title: Garbage Pail Kids

text: Each sticker card features a Garbage Pail Kid character having some comical abnormality, deformity, and/or suffering a terrible painful fate/death with a humorous word play character name such as Adam Bomb or Blasted Billy. Two versions of each card were produced, with variations featuring the same artwork but a different character name, denoted by an "a" or "b" letter after the card number. The sticker fronts are die-cut so that just the character with its nameplate and the "GPK" logo can be peeled from the backing. Many of the card backs feature puzzle pieces that form giant murals, while other flip-side subjects vary greatly among the various series, from humorous licenses and awards to comic strips and, in more recent releases, humorous Facebook profiles.


title: Garbage Pail Kids

text: 15 original series ("OS") of regular trading cards were released in the United States, with various sets released in other countries. Two large-format card editions were also released, as well as a set of fold-out posters. "All-New Series" ("ANS") sets were introduced in 2003, "Flashback" re-releases began in 2010 and a "Brand-New Series" ("BNS") was announced for 2012 with "Brand New Series 2", "Chrome S1", and "BNS3" following in 2013. A new format was released in 2014 using the year to designate the edition, followed by the release name of "Series 1", which had an Olympics-style format. In 2016, the format was changed again to themed sets that spoofed different pop culture topics.


title: Garbage Pail Kids

text: The series was the brainchild of cartoonist Art Spiegelman, then a consultant for Topps. He came up with the product idea after the success of his earlier creations "Garbage Can-dy" and "Wacky Packages". The concept originally began as an unreleased "Wacky Packages" sticker for a 1985 series, but the management at Topps thought it would be a good idea for a separate spin-off series. Spiegelman and fellow cartoonist Mark Newgarden worked together as the editors and art directors of the project, Len Brown was the manager and the first run of the cards was drawn exclusively by artist John Pound. They were first issued in 1985. Following the initial success of the cards, several additional artists and writers were brought in to contribute to the series, including Jay Lynch, Tom Bunk and James Warhola, among others.


title: Garbage Pail Kids

text: In 2020, Topps licensed Garbage Pail Kids to GPK Nation. Created by Louis Uncle Louie Gregory and Adam F. Goldberg, the company created limited edition high end collectible coins and were awarded the coveted 2020 Licensee of the year award.


title: Garbage Pail Kids

text: The cards were also known as "Bukimi Kun" [/"Mr. Creepy"] in Japan, "The Garbage Gang" in Australia and New Zealand, ' ["The Garbage Gang"] in Spain, "Havurat Ha-Zevel" ['/"The Garbage Gang"] in Israel, ' ["Trashlings"] in Latin America, "/" ["Trash Gang"/"Crazymania"] in Brazil, ' ["Snotlings"] in Italy, ' ["The Filthies"] in France and Belgium and ' ["The Totally Broken Kids"] in Germany.


title: Garbage Pail Kids

text: A smaller-sized card format was released in Australia and New Zealand. Each pack contained three stickers and the "peel here" arrow pointed to the top left area, since there was no die-cut scoring. Initially in New Zealand, a "Series 6" of the Garbage Pail Kids was released as a market test (this version was a mix of the United States "Series 6" and "7"). After this success, "Series 1" was released in Australia and New Zealand known as "The Garbage Gang" and was identical to the United States version (albeit smaller in size). The first series was released in Australia and New Zealand in 1989 with different versions: the Australian stickers were darker, had a different banner and some of the names were changed to reflect cultural differences. From "Series 2" onward, the same version was released in Australia and New Zealand. "Series 4" was the last release of "The Garbage Gang".


title: Garbage Pail Kids

text: The commercial success of the trading cards led to the production of a live-action movie, "The Garbage Pail Kids Movie", in 1987. An animated television series was also created in 1987, but its initial scheduled broadcast in the U.S. was postponed due to parental complaints. The show did make a brief appearance on U.S. television years after it was originally intended to air and was also briefly aired in Europe. The movie was released on DVD by MGM Home Entertainment on July 12, 2005 (the original VHS had been distributed by Paramount) and the animated TV series was later also released on DVD by CBS Home Entertainment on April 4, 2006 (again with distribution by Paramount). A similar set of 160 trading cards, called "The Sloppy Slobs", was released in Italy in 1993.


title: Garbage Pail Kids

text: During the height of the cards' popularity, "Garbage Pail Kids" were banned in many schools. One of the main reasons for the ban was that teachers cited them as distractions during class.


title: Garbage Pail Kids

text: Since 1988, any export and import of "Garbage Pail Kids" is banned on Mexico due to the approval of a reform to the Export and Import Law, banning all representations of minors ""in a degrading or ridiculous manner, in attitudes of incitement to violence, self-destruction or in any other form of behavior antisocial"", citing "Garbage Pail Kids" as an example.


title: Garbage Pail Kids

text: Topps was sued by the rightsholders of "Cabbage Patch Kids", Original Appalachian Artworks, for trademark infringement. As part of the out-of-court settlement, Topps agreed to modify the appearance of the Garbage Pail Kids to remove the resemblance between the characters and to change the logo design. Production of the cards themselves continued, but by 1988 sales had dwindled and a planned "Series 16" was never produced.


title: Garbage Pail Kids

text: In March 2021, Topps released a sticker card depicting a Whac-A-Mole game with members of K-pop group BTS being severely beaten with a Grammy award. After public backlash due to the card's perceived anti-Asian tone, the company apologized and withdrew the card.


title: Garbage Pail Kids

text: In 2003, Topps reintroduced "Garbage Pail Kids" with all-new artwork, dubbed the "All-New Series" ("ANS"). "ANS1" was entirely made up of artwork intended for release in the 1980s as "Series 16", but 2004's "ANS2" featured brand-new and original concepts. Unique numbers on the backs of silver foil and gold foil insert cards could be redeemed online at the official Garbage Pail Kids website, where visitors could build and "gross out" their own Garbage Pail Kids; as the number of unique code numbers applied to the character increased, the more gross it became. Less than six months later, "ANS3" was released.


title: Garbage Pail Kids

text: In 2005, Topps celebrated the 20th anniversary of the GPK franchise with special "Sketch Card" original art inserts for its "ANS4" set. These were limited to one randomly inserted card per hobby-exclusive box (available only from specialty retailers) and featured original artwork by series regulars John Pound, Tom Bunk and Jay Lynch, as well as guest artists Strephon Taylor, John Czop, Don Perlin and Justin Green. Although a regular to the series with over 35 paintings, Luis Diaz was not involved in the sketch cards due to a previous financial dispute with Topps from years earlier.


title: Garbage Pail Kids

text: In 2006, "ANS5" was released with 40 more new kids (each with an a/b twin), followed by "ANS6" in early 2007. January 2008 saw the release of "ANS7" which expanded the base set to 55 new characters and was the last set to feature new artwork until 2010's "Flashback Series 1" subset of six previously unpublished "lost" kids.


title: Garbage Pail Kids

text: The "ANS" cards differ from the original series ("OS") in a number of ways, the most obvious being the upgraded quality of the card stock with a glossy protective surface. The "ANS" releases also changed the card numbering format: "OS" cards used a continuous numbering pattern so that each new set would pick up where the last one ended (e.g. "OS1" ended at #41a/b and "OS2" picked up at #42a/b, while "ANS" reset the numbering back to #1a/b with each subsequent release). Each "ANS" also featured special chase cards randomly inserted in packs; for example, foil cards show characters from the original series (with modified artwork due to the lawsuit), "Scratch 'n Stink" cards, collectible card game cards, temporary tattoos, 3D pop-up cards, alphabet cards, activity cards, magnets, lenticular "Loco Motion" cards and die-cut jigsaw puzzle cards, along with special bonus cards available only at participating retailers in either "bonus boxes" or rack-packs; these bonus stickers were the first cards not to have a twin set.


title: Garbage Pail Kids

text: Topps released a 25th anniversary "Flashback" set on February 24, 2010, featuring reprints of characters from the original 1985–87 "GPK" series (eight each from "OS1" to "OS8") plus six previously unpublished "lost" characters and 10 "Where Are They Now?" cards, the latter showing classic GPKs drawn as they would have appeared if they had been released at that time. Packs contained randomly inserted chase cards, including lenticular "Loco Motion" cards, authentic printing plates, four levels of parallels and hand-drawn artist sketches by pop-culture artists, including Layron DeJarnette, Brent Engstrom, Dave Gross, Mark Pingitore, Joe Simko, Colin Walton, Neil Camera, Fred Wheaton, Jeff Zapata and veteran "GPK" artists Tom Bunk and Jay Lynch.


title: Garbage Pail Kids

text: A second "Flashback" set was released on February 23, 2011, with 65 more "OS" reprints from "Series 1" to "9" plus five more "lost" kids, 10 new "Where Are They Now?" cards, five 3D cards (resembling holograms but in full color), unique artist sketches and 10 "Adam Mania" cards showing variants of Adam Bomb's iconic mushroom cloud, plus parallels of the base and "Adam Mania" sets.


title: Garbage Pail Kids

text: "GPK Flashback Series 3" followed on November 2, 2011, with 65 "OS" reprints, four more "lost" kids, 10 new "WATN?" cards, five more 3D cards, 10 more "Adam Mania" cards, plus artist sketches and parallels.


title: Garbage Pail Kids

text: Topps and Abrams Books recently released a hardcover book that showcases the first five series. The cover depicts a pack from the very first series released back in 1985. Each card is displayed with the "a" name and the "b" name on the bottom corner of the page. It also included four new chase cards that were wrapped in cellophane and adhered to the inside back cover of the book, but were easily removable without running the risk of damaging the book.


title: Garbage Pail Kids

text: In 2012, Topps announced it would reboot the Garbage Pail Kids franchise with new character and content themes more reminiscent of the original 1980s series in a set called "Brand-New Series 1" ("BNS1"). The set was released on October 24, 2012. "BNS1" features 55 new "GPK" characters, a reality TV subset, motion cards, mix 'n' match stickers, parallels, artist sketch cards and code cards redeemable for a chance to be painted as a GPK in the next "BNS". "BNS2" was released in March and features 55 new characters, 18 reimagined characters, lenticular cards, glow in the dark cards and folded cards. Unlike the "All-New Series" set and like the old series sets, the numbering of "BNS" continues where the previous series ended. They have now announced that there will be a "BNS3" released in the middle of October, after the release of the "Chrome" edition in August.


title: Garbage Pail Kids

text: In October 2013, Topps re-released the original "Series 1" as a metallic chromium card set containing all 41 kids, plus 14 previously unpublished "lost" kids.


title: Garbage Pail Kids

text: On July 30, 2014, Topps re-released 1985's original "Series 2" set, plus 13 returning characters from "Series 2" characters that have been reimagined in previous "Garbage Pail Kids" sets also as a set of metallic chromium cards. "Chrome Series" cards are thicker than the original cards and are not stickers.


title: Garbage Pail Kids

text: Topps released a series of all-new cards with brand-new artwork for 2014. Like the older cards, these have activities on the back of the cards, including checklists, puzzles and "Fakebook" profiles.


title: Garbage Pail Kids

text: In July 2015, Topps released the "30th Anniversary Series" with 110 a/b cards (220 cards total). The numbering differed from previous series in that, instead of ranging from #1–110a/b, it had several themed subsets, each of which started at #1 a/b with the subsets being checklist cards featuring variations of Adam Bomb (#1–2a/b), including "Adam Bomb: Don't Push My Button", featuring classic "GPK" characters pressing Adam Bomb's button (#1–10a/b), "Artistic Impression", featuring historical art as "GPK" characters (#1–10a/b), "Artistic Interpretation", featuring characters drawn by guest artists (#1–5a/b), "Comic Book Covers", featuring art from the comic books (#1–7a/b), "Cutting Room Floor", featuring rejected concepts (#1–5a/b), "Garbage Pail Kids' Kids", featuring the children of classic GPKs (#1–10a/b), "Garbage Pail Pets", featuring animals as Garbage Pail Kids (#1–10a/b), "Garbage Pail Presidents", featuring 10 former U.S. Presidents as Garbage Pail Kids (#1–10a/b), "Lost Original Art", featuring the original paintings of classic GPKs which were never before published (#1–6a/b), "Zoom Out", featuring zoomed-out GPKs showing what happened in the background (#1–10a/b) and " '80s Spoofs", featuring parodies of things that were popular in the 1980s (#1–25a/b).


title: Garbage Pail Kids

text: After the "30th Anniversary Series", Topps began using a new formula that structured each series with an overall theme divided into subsets focusing on particular topics. In January 2016, "As American as Apple Pie In Your Face!" put GPKs in situations that parodied American culture. A second 2016 series followed in April called "Prime Slime Trashy TV" with humorous takes on popular television shows. The first series for 2017 was January's "Adam-geddon", which put the Garbage Pail Kids (including some classic kids) in perilous end-times scenarios. Topps announced that the second series for 2017 will arrive in October and be called "Battle of the Bands", caricaturing popular music acts and album covers.


title: Garbage Pail Kids

text: In April 2020, Topps announced they will celebrate the 35th anniversary by bringing digital collectible "Garbage Pail Kids" cards to the Blockchain. Topps chose to partner with the WAX blockchain. The WAX blockchain uses the EOS.IO smart contract platform. On May 12, 2020, the "Garbage Pail Kids" card packs launched on the WAX blockchain and were sold out in 28 hours. Each card is certified authentic, unique and can never be altered. This is a limited edition series and only a finite number of cards will ever be created (110,000). The cards come in one of four rarities:


title: Garbage Pail Kids

text: The first buyers of "Garbage Pail Kids" card packs on WAX were automatically entered to win an Ultra-Rare Golden Card. Only 100 of these Golden Cards will ever be minted. Golden Cards come in the original 41 characters, each with an "A" name and a "B" name. The "Garbage Pail Kids" on the WAX card series feature the original 41 characters, each with an “A” name and a “B” name.


title: Garbage Pail Kids

text: Collectors can trade their digital cards with others, showcase their inventory on social media and gift their cards to friends. Trades are instant and free on the WAX blockchain and every card's complete trading history and ownership records are stored on the WAX blockchain.


title: Garbage Pail Kids

text: On August 21, 1987, a live-action film based on the card characters was released. Its campy production made it both a critical and commercial flop, opening poorly in 374 theaters with initial receipts of $661,512 and total gross receipts of $1,576,615, barely making back its $1,000,000 budget. On Rotten Tomatoes, the film holds a 0% critic rating. The film is considered one of the worst films ever made. Topps featured advertisements for the movie on the original "Series 9" and "10" box-topper poster and variant wrapper.


title: Garbage Pail Kids

text: On March 12, 2012, it was announced that Michael Eisner's Tornante Company would be producing a new movie based on the Garbage Pail Kids, likely with computer-generated character imagery. Michael Vukadinovich was hired to write the screenplay for the film and PES has been hired to direct.


title: Garbage Pail Kids

text: In May 2021, it was announced that a new animated series is in the works at HBO Max, and would be co-produced by Topps, Tornante Company and Danny McBride's production company Rough House Pictures.


title: Ann B. Davis

text: Ann Bradford Davis (May 3, 1926 – June 1, 2014) was an American actress. She achieved prominence for her role in the NBC situation comedy "The Bob Cummings Show" (1955–1959), for which she twice won the Primetime Emmy Award for Outstanding Supporting Actress in a Comedy Series, but she was best known for playing the part of Alice Nelson, the housekeeper in ABC's "The Brady Bunch" (1969–1974).


title: Ann B. Davis

text: Davis was born in Schenectady, New York, the daughter of Marguerite (née Stott) and Cassius Miles Davis. She had an identical twin, Harriet, and an older sister and brother, Elizabeth (1917-1974) and Evans (1921-2005). When she was three, she and her family moved to Erie in northwestern Pennsylvania. She graduated from Strong Vincent High School and later from the University of Michigan in Ann Arbor. She originally enrolled as a pre-medical major; however, she changed her mind and went into drama after seeing her older brother's performance of "Oklahoma!" Davis graduated in 1948 with a degree in drama and speech.


title: Ann B. Davis

text: Davis's first television success was as Charmaine "Schultzy" Schultz in "The Bob Cummings Show", 1955–1959. She auditioned for the role because her friend's boyfriend was a casting director and recommended her for the part. She won the Primetime Emmy Award for Outstanding Supporting Actress in a Comedy Series twice out of four nominations for this role.


title: Ann B. Davis

text: She appeared on January 23, 1958, as a guest star on "The Ford Show, Starring Tennessee Ernie Ford". On February 9, 1960, Davis received a star on the Hollywood Walk of Fame. In this period, Davis also focused on theater. As early as 1958 she appeared in a national touring company of the Thornton Wilder play "The Matchmaker", costarring her "Bob Cummings Show" castmate, Lyle Talbot, who played Bob's Air Force buddy, and in about 1960 she replaced Carol Burnett in the starring role of Princess Winnifred in the Broadway production of the musical "Once Upon a Mattress".


title: Ann B. Davis

text: In the 1965–1966 television season, Davis appeared as Miss Wilson, a physical education teacher at a private girls' academy in John Forsythe's single-season NBC sitcom, "The John Forsythe Show".


title: Ann B. Davis

text: For a period in the 1960s and 1970s, Davis was known for her appearances in television commercials for the Ford Motor Company, particularly for the mid-sized Ford Fairlane models. Davis was also featured in commercials for Minute Rice in Canada until the mid-1980s. During this period she also performed as a stand-up comedian; before Sherwood Schwartz could cast her in "The Brady Bunch", Paramount Studios had to buy her out of a multiweek booking in Seattle.


title: Ann B. Davis

text: From 1969 to 1974, Davis played housekeeper Alice Nelson in "The Brady Bunch" television series. She later returned to take part in various "Brady Bunch" television movies, including "The Brady Girls Get Married" (1981) and "A Very Brady Christmas" (1988). She also reprised her role as Alice Nelson in two short-lived Brady Bunch spin-off television series: "The Brady Brides" (1981) and "The Bradys" (1990), both of which lasted only six episodes. She also made a cameo appearance as a truck driver named "Schultzy", a reference to her days on "The Bob Cummings Show", in "The Brady Bunch Movie" in 1995. In 1994, Davis published a cookbook, "Alice's Brady Bunch Cookbook", with "Brady Bunch" inspired recipes. The book also includes recipes from cast members.


title: Ann B. Davis

text: In the early 1990s, Davis returned to theater. She performed in a production of "Arsenic and Old Lace", and both the Broadway production and a world tour of "Crazy for You".


title: Ann B. Davis

text: Davis never completely retired from acting; in her later years she was the celebrity spokeswoman in several Shake 'n Bake commercials, and later appeared in several disposable mop commercials for Swiffer. She also appeared in a number of "Brady Bunch" reunion projects, most recently TV Land's "". On April 22, 2007, "The Brady Bunch" was awarded the TV Land Pop Culture Award on the 5th annual TV Land Awards. Davis and other cast members accepted the award, and she received a standing ovation.


title: Ann B. Davis

text: In 1976, Davis sold her home in Los Angeles to move to Denver, Colorado, where she joined an Episcopal community led by Bishop William C. Frey. The community later relocated to Ambridge in Beaver County in far western Pennsylvania after Frey became dean of the seminary Trinity School for Ministry. Davis had long been a volunteer for the Episcopal Church, working at the General Convention, attending services at churches around the country.


title: Ann B. Davis

text: Davis died at the age of 88 on June 1, 2014, at a hospital in San Antonio, Texas. Earlier in the day, she had sustained a subdural hematoma from a fall in her bathroom in her San Antonio residence, in which she lived with Bishop Frey and his wife, Barbara. Sources close to her say she was in excellent health for her age and her death was a complete shock. She is interred in the Saint Helena's Columbarium and Memorial Gardens in Boerne, Texas.


title: Ann B. Davis

text: Davis received four Primetime Emmy Award nominations, resulting in two awards, for her portrayal of Charmaine "Schultzy" Schultz on "The Bob Cummings Show".


title: Ann B. Davis

text: On February 9, 1960, Davis also received a star on the Hollywood Walk of Fame at 7048 Hollywood Boulevard. She also received TV Land Awards in 2004, 2006, and 2007 for her portrayal of Alice Nelson, the housekeeper on "The Brady Bunch".


title: Olm

text: The olm or proteus ("Proteus anguinus") is an aquatic salamander in the family Proteidae, the only exclusively cave-dwelling chordate species found in Europe. In contrast to most amphibians, it is entirely aquatic, eating, sleeping, and breeding underwater. Living in caves found in the Dinaric Alps, it is endemic to the waters that flow underground through the extensive limestone bedrock of the karst of Central and Southeastern Europe in the basin of the Soča River () near Trieste, Italy, southwestern Croatia, and Bosnia and Herzegovina. Introduced populations are found near Vicenza, Italy, and Kranj, Slovenia.


title: Olm

text: It is also called the "human fish" by locals because of its fleshy skin color (translated literally from , , , ), as well as "cave salamander" or "white salamander". In Slovenia, it is called "močeril" (from *"močerъ" 'earthworm, damp creepy-crawly'; "moča" 'dampness'). It was first mentioned in 1689 by the local naturalist Valvasor in his "Glory of the Duchy of Carniola", who reported that, after heavy rains, the olms were washed up from the underground waters and were believed by local people to be a cave dragon's offspring.


title: Olm

text: This cave salamander is most notable for its adaptations to a life of complete darkness in its underground habitat. The olm's eyes are undeveloped, leaving it blind, while its other senses, particularly those of smell and hearing, are acutely developed. It also lacks any pigmentation in its skin. It has three toes on its forelimbs, but only two toes on its hind feet. It exhibits neoteny, retaining larval characteristics like external gills into adulthood, like some American amphibians, the axolotl and the mudpuppies ("Necturus"). The olm is the only species in the genus "Proteus" and the only European species of the family Proteidae, whose other extant genus is "Necturus".


title: Olm

text: The word "olm" is a German loanword that was incorporated into English in the late 19th century. The origin of the German original, or 'cave olm', is unclear. It may be a variant of the word 'salamander'.


title: Olm

text: The olm's body is snakelike, long, with some specimens reaching up to . The average length is between 23-25 cm. Females grow larger than males, but otherwise the primary external difference between the sexes is in the cloaca region (shape and size) when breeding. The trunk is cylindrical, uniformly thick, and segmented with regularly spaced furrows at the myomere borders. The tail is relatively short, laterally flattened, and surrounded by a thin fin. The limbs are small and thin, with a reduced number of digits compared to other amphibians: the front legs have three digits instead of the normal four, and the rear have two digits instead of five. Its body is covered by a thin layer of skin, which contains very little of the pigment riboflavin, making it yellowish-white or pink in color.


title: Olm

text: The white skin color of the olm retains the ability to produce melanin, and will gradually turn dark when exposed to light; in some cases the larvae are also colored. Its pear-shaped head ends with a short, dorsoventrally flattened snout. The mouth opening is small, with tiny teeth forming a sieve to keep larger particles inside the mouth. The nostrils are so small as to be imperceptible, but are placed somewhat laterally near the end of the snout. The regressed eyes are covered by a layer of skin. The olm breathes with external gills that form two branched tufts at the back of the head. They are red in color because the oxygen-rich blood shows through the non-pigmented skin. The olm also has rudimentary lungs, but their role in respiration is only accessory, except during hypoxic conditions.


title: Olm

text: Cave-dwelling animals have been prompted, among other adaptations, to develop and improve non-visual sensory systems in order to orient in and adapt to permanently dark habitats. The olm's sensory system is also adapted to life in the subterranean aquatic environment. Unable to use vision for orientation, the olm compensates with other senses, which are better developed than in amphibians living on the surface. It retains larval proportions, like a long, slender body and a large, flattened head, and is thus able to carry a larger number of sensory receptors.


title: Olm

text: Although blind, the olm swims away from light. The eyes are regressed, but retain sensitivity. They lie deep below the dermis of the skin and are rarely visible except in some younger adults. Larvae have normal eyes, but development soon stops and they start regressing, finally atrophying after four months of development. The pineal body also has photoreceptive cells which, though regressed, retain visual pigment like the photoreceptive cells of the regressed eye. The pineal gland in "Proteus" probably possesses some control over the physiological processes. Behavioral experiments revealed that the skin itself is also sensitive to light. Photosensitivity of the integument is due to the pigment melanopsin inside specialized cells called melanophores. Preliminary immunocytochemical analyses support the existence of photosensitive pigment also in the animal's integument.


title: Olm

text: The olm is capable of sensing very low concentrations of organic compounds in the water. They are better at sensing both the quantity and quality of prey by smell than related amphibians. The nasal epithelium, located on the inner surface of the nasal cavity and in the Jacobson's organ, is thicker than in other amphibians. The taste buds are in the mucous epithelium of the mouth, most of them on the upper side of the tongue and on the entrance to the gill cavities. Those in the oral cavity are used for tasting food, where those near the gills probably sense chemicals in the surrounding water.


title: Olm

text: The sensory epithelia of the inner ear are very specifically differentiated, enabling the olm to receive sound waves in the water, as well as vibrations from the ground. The complex functional-morphological orientation of the sensory cells enables the animal to register the sound sources. As this animal stays neotenic throughout its long life span, it is only occasionally exposed to normal adult hearing in air, which is probably also possible for Proteus as in most salamanders. Hence, it would be of adaptive value in caves, with no vision available, to profit from underwater hearing by recognizing particular sounds and eventual localization of prey or other sound sources, i.e. acoustical orientation in general. The ethological experiments indicate that the best hearing sensitivity of "Proteus" is between 10 Hz and up to 15,000 Hz. The lateral line supplements inner ear sensitivity by registering low-frequency nearby water displacements.


title: Olm

text: A new type of electroreception sensory organ has been analyzed on the head of "Proteus", utilizing light and electron microscopy. These new organs have been described as ampullary organs.


title: Olm

text: Like some other lower vertebrates, the olm has the ability to register weak electric fields. Some behavioral experiments suggest that the olm may be able to use Earth's magnetic field to orient itself. In 2002, "Proteus" "anguinus" was found to align itself with natural and artificially modified magnetic fields.


title: Olm

text: The olm lives in well-oxygenated underground waters with a typical, very stable temperature of , infrequently as warm as . The black olm may occur in surface waters that are somewhat warmer.


title: Olm

text: At a temperature of , the olm's embryonic development (time in the eggs before hatching) is 140 days, but it is somewhat slower in colder water and faster in warmer, being as little as 86 days at . After hatching, it takes another 14 years to reach sexual maturity if living in water that is . The larvae gain adult appearance after nearly four months, with the duration of development strongly correlating with water temperature. Unconfirmed historical observations of viviparity exist, but it has been shown that the females possess a gland that produces the egg casing, similar to those of fish and egg-laying amphibians. Paul Kammerer reported that female olm gave birth to live young in water at or below and laid eggs at higher, but rigorous observations have not confirmed that. The olm appears to be exclusively oviparous.


title: Olm

text: The female lays up to 70 eggs, each about in diameter, and places them between rocks, where they remain under her protection. The average is 35 eggs and the adult female typically breeds every 12.5 years. The tadpoles are long when they hatch and live on yolk stored in the cells of the digestive tract for a month.


title: Olm

text: Development of the olm and other troglobite amphibians is characterized by heterochrony – the animal does not undergo metamorphosis and instead retains larval features. The form of heterochrony in the olm is neoteny – delayed somatic maturity with precocious reproductive maturity, i.e. reproductive maturity is reached while retaining the larval external morphology. In other amphibians, the metamorphosis is regulated by the hormone thyroxine, secreted by the thyroid gland. The thyroid is normally developed and functioning in the olm, so the lack of metamorphosis is due to the unresponsiveness of key tissues to thyroxine.


title: Olm

text: The olm swims by eel-like twisting of its body, assisted only slightly by its poorly developed legs. It is a predatory animal, feeding on small crustaceans (for example, "Troglocaris" shrimp), snails and occasionally insects. It does not chew its food, instead swallowing it whole. The olm is resistant to long-term starvation, an adaptation to its underground habitat. It can consume large amounts of food at once, and store nutrients as large deposits of lipids and glycogen in the liver. When food is scarce, it reduces its activity and metabolic rate, and can also reabsorb its own tissues in severe cases. Controlled experiments have shown that an olm can survive up to 10 years without food.


title: Olm

text: Olms are gregarious, and usually aggregate either under stones or in fissures. Sexually active males are an exception, establishing and defending territories where they attract females. The scarcity of food makes fighting energetically costly, so encounters between males usually only involve display. This is a behavioral adaptation to life underground.


title: Olm

text: Reproduction has only been observed in captivity so far. Sexually mature males have swollen cloacas, brighter skin color, two lines at the side of the tail, and slightly curled fins. No such changes have been observed in the females. The male can start courtship even without the presence of a female. He chases other males away from the chosen area, and may then secrete a female-attracting pheromone. When the female approaches, he starts to circle around her and fan her with his tail. Then he starts to touch the female's body with his snout, and the female touches his cloaca with her snout. At that point, he starts to move forward with a twitching motion, and the female follows. He then deposits the spermatophore, and the animals keep moving forward until the female hits it with her cloaca, after which she stops and stands still. The spermatophore sticks to her and the sperm cells swim inside her cloaca, where they attempt to fertilize her eggs. The courtship ritual can be repeated several times over a couple of hours.


title: Olm

text: Longevity is estimated at up to 58 years. A study published in "Biology Letters" estimated that they have a maximum lifespan of over 100 years and that the lifespan of an average adult is around 68.5 years. When compared to the longevity and body mass of other amphibians, olms are outliers, living longer than would be predicted from their size.


title: Olm

text: Olms from different cave systems differ substantially in body measurements, color and some microscopic characteristics. Earlier researchers used these differences to support the division into five species, while modern herpetologists understand that external morphology is not reliable for amphibian systematics and can be extremely variable, depending on nourishment, illness, and other factors; even varying among individuals in a single population. "Proteus anguinus" is now considered a single species. The length of the head is the most obvious difference between the various populations – individuals from Stična, Slovenia, have shorter heads on average than those from Tržič, Slovenia, and the Istrian peninsula, for example.


title: Olm

text: The black olm ("Proteus anguinus parkelj" ) is the only other recognized subspecies of the olm. It is endemic to the underground waters near Črnomelj, Slovenia, an area smaller than . It was first found in 1986 by members of the Slovenian Karst Research Institute, who were exploring the water from Dobličica karst spring in the White Carniola region.


title: Olm

text: These features suggest that the black olm has probably colonized underground habitats more recently and still retains some nontroglomorphic characteristics.


title: Olm

text: The first written mention of the olm is in Johann Weikhard von Valvasor's "The Glory of the Duchy of Carniola" (1689) as a baby dragon. Heavy rains of Slovenia would wash the olms up from their subterranean habitat, giving rise to the folklore belief that great dragons lived beneath the Earth's crust, and the olms were the undeveloped offspring of these mythical beasts. In his book Valvasor compiled the local Slovenian folk stories and pieced together the rich mythology of the creature and documented observations of the olm as "Barely a span long, akin to a lizard, in short, a worm and vermin of which there are many hereabouts".


title: Olm

text: The first researcher to retrieve a live olm was a physician and researcher from Idrija, Giovanni Antonio Scopoli, who sent dead specimens and drawings to colleagues and collectors. Josephus Nicolaus Laurenti, though, was the first to briefly describe the olm in 1768 and give it the scientific name "Proteus anguinus". It was not until the end of the century that Carl Franz Anton Ritter von Schreibers from the Naturhistorisches Museum of Vienna started to look into this animal's anatomy. The specimens were sent to him by Sigmund Zois. Schreibers presented his findings in 1801 to The Royal Society in London, and later also in Paris. Soon, the olm started to gain wide recognition and attract significant attention, resulting in thousands of animals being sent to researchers and collectors worldwide. A Dr Edwards was quoted in a book of 1839 as believing that "...the Proteus Anguinis is the first stage of an animal prevented from growing to perfection by inhabiting the subterraneous waters of Carniola."


title: Olm

text: In 1880 Marie von Chauvin began the first long-term study of olms in captivity. She learned that they detected prey's motion, panicked when a heavy object was dropped near their habitat, and developed color if exposed to weak light for a few hours a day, but could not cause them to change to a land-dwelling adult form, as she and others had done with axolotl.


title: Olm

text: The basis of functional morphological investigations in Slovenia was set up by Lili Istenič in the 1980s. More than twenty years later, the Research Group for functional morphological Studies of the Vertebrates in the Department of Biology (Biotechnical Faculty, University of Ljubljana), is one of the leading groups studying the olm under the guidance of Boris Bulog. There are also several cave laboratories in Europe in which olms have been introduced and are being studied. These are Moulis, Ariège (France), Kent's Cavern (England), Han-sur-Lesse (Belgium) and Aggtelek (Hungary). They were also introduced into the Hermannshöhle (Germany) and Oliero (Italy) caves, where they still live today. Additionally, there is evidence that a small number of olms were introduced to the United Kingdom in the 1940s, although it's highly likely that the animals perished shortly after being released.


title: Olm

text: The olm was used by Charles Darwin in his seminal work "On the Origin of Species" as an example for the reduction of structures through disuse:


title: Olm

text: An olm (Proteus) genome project is currently underway by the University of Ljubljana and BGI. With an estimated genome size roughly 15-times the size of human genome, this will likely be the largest animal genome sequenced so far.


title: Olm

text: The olm is extremely vulnerable to changes in its environment, due to its adaptation to the specific conditions in caves. Water resources in the karst are extremely sensitive to all kinds of pollution. The contamination of the karst underground waters is due to the large number of waste disposal sites leached by rainwater, as well as to the accidental overflow of various liquids. The reflection of such pollution in the karst underground waters depends on the type and quantity of pollutants, and on the rock structure through which the waters penetrate. Self-purification processes in the underground waters are not completely understood, but they are quite different from those in surface waters.


title: Olm

text: Among the most serious chemical pollutants are chlorinated hydrocarbon pesticides, fertilizers, polychlorinated biphenyls (PCBs), which are or were used in a variety of industrial processes and in the manufacture of many kinds of materials; and metals such as mercury, lead, cadmium, and arsenic. All of these substances persist in the environment, being slowly, if at all, degraded by natural processes. In addition, all are toxic to life if they accumulate in any appreciable quantity.


title: Olm

text: The olm was included in annexes II and IV of the 1992 EU Habitats Directive (92/43/EEC). The list of species in annex II, combined with the habitats listed in annex I, is used by individual countries to designate protected areas known as 'Special Areas of Conservation'. These areas, combined with others created by the older Birds Directive were to form the Natura 2000 network. Annex IV additionally lists "animal and plant species of community interest in need of strict protection", although this has little legal ramifications. Postojna Cave and other caves inhabited by the olm were eventually included in the Slovenian part of the Natura 2000 network. Capturing or killing olm is allowed only under specific circumstances determined by the local authorities (i.e. scientific study).


title: Olm

text: The olm was first protected in Slovenia in 1922 along with all cave fauna, but the protection was not effective and a substantial black market came into existence. In 1982 it was placed on a list of rare and endangered species. This list also had the effect of prohibiting trade of the species. After joining the European Union in 2004, Slovenia had to establish mechanisms for protection of the species included in the EU Habitats Directive. The olm is included in a "Slovenian Red list" of endangered species.


title: Olm

text: In Croatia, the olm is protected by the legislation designed to protect amphibians – collecting is possible only for research purposes by permission of the National Administration for Nature and Environment Protection. As of 2020 the Croatian population has been assessed as 'critically endangered' in Croatia. As of 1999, the environmental laws in Bosnia and Herzegovina and Montenegro had not yet been clarified for this species.


title: Olm

text: In the 1980s the IUCN claimed that some illegal collection of this species for the pet trade took place, but that the extent of this was unknown: this text has been copied into all subsequent assessments. Since the 1980s until the most recent assessment in 2008 the organisation has rated the conservation status for the IUCN Red List as 'vulnerable', this because of its natural distribution being fragmented over a number of cave systems as opposed to being continuous, and what they consider a decline in extent and quality of its habitat, which they assume means that the population has been decreasing for the last 40 years.


title: Olm

text: Zagreb Zoo is a zoo in Croatia that houses the olm. Olms were until recently formerly kept in numerous zoos in Germany, as well as in the UK, Belgium and Slovenia. At present they can only be experienced at Zagreb Zoo, "Hermannshöhle" in Germany and Vivarium Proteus (Proteus Vivarium) within "Postojnska jama" (Postojna Cave) in Slovenia. There are also captive breeding programs in France and Germany.


title: Olm

text: The olm is a symbol of Slovenian natural heritage. The enthusiasm of scientists and the broader public about this inhabitant of Slovenian caves is still strong 300 years after its discovery. Postojna Cave is one of the birthplaces of biospeleology due to the olm and other rare cave inhabitants, such as the blind cave beetle. The image of the olm contributes significantly to the fame of Postojna Cave, which Slovenia successfully utilizes for the promotion of ecotourism in Postojna and other parts of Slovenian karst. Tours of Postojna Cave also include a tour around the speleobiological station – the Proteus vivarium, showing different aspects of the cave environment.


title: Olm

text: The olm was also depicted on one of the Slovenian tolar coins. It was also the namesake of "Proteus", the oldest Slovenian popular science magazine, first published in 1933.


title: Reproductive system

text: The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are also important accessories to the reproductive system. Unlike most organ systems, the sexes of differentiated species often have significant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the offspring.


title: Reproductive system

text: In mammals, the major organs of the reproductive system include the external genitalia (penis and vulva) as well as a number of internal organs, including the gamete-producing gonads (testicles and ovaries). Diseases of the human reproductive system are very common and widespread, particularly communicable sexually transmitted diseases.


title: Reproductive system

text: Most other vertebrates have similar reproductive systems consisting of gonads, ducts, and openings. However, there is a great diversity of physical adaptations as well as reproductive strategies in every group of vertebrates.


title: Reproductive system

text: Vertebrates share key elements of their reproductive systems. They all have gamete-producing organs known as gonads. In females, these gonads are then connected by oviducts to an opening to the outside of the body, typically the cloaca, but sometimes to a unique pore such as a vagina or intromittent organ.


title: Reproductive system

text: The human reproductive system usually involves internal fertilization by sexual intercourse. During this process, the male inserts their erect penis into the female's vagina and ejaculates semen, which contains sperm. The sperm then travels through the vagina and cervix into the uterus or fallopian tubes for fertilization of the ovum. Upon successful fertilization and implantation, gestation of the fetus then occurs within the female's uterus for approximately nine months, this process is known as pregnancy in humans. Gestation ends with childbirth, delivery following labor. Labor consists of the muscles of the uterus contracting, the cervix dilating, and the baby passing out the vagina (the female genital organ). Human's babies and children are nearly helpless and require high levels of parental care for many years. One important type of parental care is the use of the mammary glands in the female breasts to nurse the baby.


title: Reproductive system

text: The female reproductive system has two functions: The first is to produce egg cells, and the second is to protect and nourish the offspring until birth. The male reproductive system has one function, and it is to produce and deposit sperm. Humans have a high level of sexual differentiation. In addition to differences in nearly every reproductive organ, numerous differences typically occur in secondary sexual characteristics.


title: Reproductive system

text: The male reproductive system is a series of organs located outside of the body and around the pelvic region of a male that contribute towards the reproduction process. The primary direct function of the male reproductive system is to provide the male sperm for fertilization of the ovum.


title: Reproductive system

text: The major reproductive organs of the male can be grouped into three categories. The first category is sperm production and storage. Production takes place in the testes which are housed in the temperature regulating scrotum, immature sperm then travel to the epididymis for development and storage. The second category is the ejaculatory fluid-producing glands which include the seminal vesicles, prostate, and the vas deferens. The final category are those used for copulation, and deposition of the spermatozoa (sperm) within the male, these include the penis, urethra, vas deferens, and Cowper's gland.


title: Reproductive system

text: Major secondary sex characteristics include larger, more muscular stature, deepened voice, facial and body hair, broad shoulders, and development of an Adam's apple. An important sexual hormone of males is androgen, and particularly testosterone.


title: Reproductive system

text: The testes release a hormone that controls the development of sperm. This hormone is also responsible for the development of physical characteristics in men such as facial hair and a deep voice.


title: Reproductive system

text: The human female reproductive system is a series of organs primarily located inside of the body and around the pelvic region of a female that contribute towards the reproductive process. The human female reproductive system contains three main parts: the vulva, which leads to the vagina, the vaginal opening, to the uterus; the uterus, which holds the developing fetus; and the ovaries, which produce the female's ova. The breasts are involved during the parenting stage of reproduction, but in most classifications they are not considered to be part of the female reproductive system.


title: Reproductive system

text: The vagina meets the outside at the vulva, which also includes the labia, clitoris and urethra; during intercourse this area is lubricated by mucus secreted by the Bartholin's glands. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the fallopian tubes. Each ovary contains hundreds of ova (singular "ovum").


title: Reproductive system

text: Approximately every 28 days, the pituitary gland releases a hormone that stimulates some of the ova to develop and grow. One ovum is released and it passes through the fallopian tube into the uterus. Hormones produced by the ovaries prepare the uterus to receive the ovum. The ovum will move through her fallopian tubes and awaits the sperm for fertilization to occur. When this does not occur i.e. no sperm for fertilization, the lining of the uterus, called the endometrium, and unfertilized ova are shed each cycle through the process of menstruation. If the ovum is fertilized by sperm, it will attach to the endometrium and embryonic development will begin.


title: Reproductive system

text: Most mammal reproductive systems are similar, however, there are some notable differences between the non-human mammals and humans. For instance, most male mammals have a penis which is stored internally until erect, and most have a penis bone or baculum. Additionally, males of most species do not remain continually sexually fertile as humans do. Like humans, most groups of mammals have descended testicles found within a scrotum, however, others have descended testicles that rest on the ventral body wall, and a few groups of mammals, such as elephants, have undescended testicles found deep within their body cavities near their kidneys.


title: Reproductive system

text: The reproductive system of marsupials is unique in that the female has two vaginae, both of which open externally through one orifice but lead to different compartments within the uterus; males usually have a two-pronged penis, which corresponds to the females' two vaginae. Marsupials typically develop their offspring in an external pouch containing teats to which their newborn young (joeys) attach themselves for post uterine development. Also, marsupials have a unique prepenial scrotum. The long newborn joey instinctively crawls and wriggles the , while clinging to fur, on the way to its mother's pouch.


title: Reproductive system

text: The uterus and vagina are unique to mammals with no homologue in birds, reptiles, amphibians, or fish. In place of the uterus the other vertebrate groups have an unmodified oviduct leading directly to a cloaca, which is a shared exit-hole for gametes, urine, and feces. Monotremes (i.e. platypus and echidnas), a group of egg-laying mammals, also lack a uterus and vagina, and in that respect have a reproductive system resembling that of a reptile.


title: Reproductive system

text: In domestic canines, sexual maturity (puberty) occurs between the ages of 6 to 12 months for both males and females, although this can be delayed until up to two years of age for some large breeds.


title: Reproductive system

text: The mare's reproductive system is responsible for controlling gestation, birth, and lactation, as well as her estrous cycle and mating behavior. The stallion's reproductive system is responsible for his sexual behavior and secondary sex characteristics (such as a large crest).


title: Reproductive system

text: Male and female birds have a cloaca, an opening through which eggs, sperm, and wastes pass. Intercourse is performed by pressing the lips of the cloacae together, which is sometimes known as intromittent organ which is known as a phallus that is analogous to the mammals' penis. The female lays amniotic eggs in which the young fetus continues to develop after it leaves the female's body. Unlike most vertebrates female birds typically have only one functional ovary and oviduct. As a group, birds, like mammals, are noted for their high level of parental care.


title: Reproductive system

text: Reptiles are almost all sexually dimorphic, and exhibit internal fertilization through the cloaca. Some reptiles lay eggs while others are ovoviviparous (animals that deliver live young). Reproductive organs are found within the cloaca of reptiles. Most male reptiles have copulatory organs, which are usually retracted or inverted and stored inside the body. In turtles and crocodilians, the male has a single median penis-like organ, while male snakes and lizards each possess a pair of penis-like organs.


title: Reproductive system

text: Most amphibians exhibit external fertilization of eggs, typically within the water, though some amphibians such as caecilians have internal fertilization. All have paired, internal gonads, connected by ducts to the cloaca.


title: Reproductive system

text: Fish exhibit a wide range of different reproductive strategies. Most fish, however, are oviparous and exhibit external fertilization. In this process, females use their cloaca to release large quantities of their gametes, called spawn into the water and one or more males release "milt", a white fluid containing many sperm over the unfertilized eggs. Other species of fish are oviparous and have internal fertilization aided by pelvic or anal fins that are modified into an intromittent organ analogous to the human penis. A small portion of fish species are either viviparous or ovoviviparous, and are collectively known as livebearers.


title: Reproductive system

text: Fish gonads are typically pairs of either ovaries or testes. Most fish are sexually dimorphic but some species are hermaphroditic or unisexual.


title: Reproductive system

text: Invertebrates have an extremely diverse array of reproductive systems, the only commonality may be that they all lay eggs. Also, aside from cephalopods and arthropods, nearly all other invertebrates are hermaphroditic and exhibit external fertilization.


title: Reproductive system

text: All cephalopods are sexually dimorphic and reproduce by laying eggs. Most cephalopods have semi-internal fertilization, in which the male places his gametes inside the female's mantle cavity or pallial cavity to fertilize the ova found in the female's single ovary. Likewise, male cephalopods have only a single testicle. In the female of most cephalopods the nidamental glands aid in development of the egg.


title: Reproductive system

text: The "penis" in most unshelled male cephalopods (Coleoidea) is a long and muscular end of the gonoduct used to transfer spermatophores to a modified arm called a hectocotylus. That in turn is used to transfer the spermatophores to the female. In species where the hectocotylus is missing, the "penis" is long and able to extend beyond the mantle cavity and transfer the spermatophores directly to the female.


title: Reproductive system

text: Most insects reproduce oviparously, i.e. by laying eggs. The eggs are produced by the female in a pair of ovaries. Sperm, produced by the male in one testis or more commonly two, is transmitted to the female during mating by means of external genitalia. The sperm is stored within the female in one or more spermathecae. At the time of fertilization, the eggs travel along oviducts to be fertilized by the sperm and are then expelled from the body ("laid"), in most cases via an ovipositor.


title: Reproductive system

text: Arachnids may have one or two gonads, which are located in the abdomen. The genital opening is usually located on the underside of the second abdominal segment. In most species, the male transfers sperm to the female in a package, or spermatophore. Complex courtship rituals have evolved in many arachnids to ensure the safe delivery of the sperm to the female.


title: Reproductive system

text: Arachnids usually lay yolky eggs, which hatch into immatures that resemble adults. Scorpions, however, are either ovoviviparous or viviparous, depending on species, and bear live young.


title: Reproductive system

text: Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants (green algae, mosses, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it was understood that the pollination process involved both biotic and abiotic interactions.


title: Reproductive system

text: Fungal reproduction is complex, reflecting the differences in lifestyles and genetic makeup within this diverse kingdom of organisms. It is estimated that a third of all fungi reproduce using more than one method of propagation; for example, reproduction may occur in two well-differentiated stages within the life cycle of a species, the teleomorph and the anamorph. Environmental conditions trigger genetically determined developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. These structures aid reproduction by efficiently dispersing spores or spore-containing propagules.


title: Alexander Gilkes

text: Alexander Mark Heming Gilkes (born July 1979) is a British businessman. He is the co-founder of Squared Circles, launched in 2020, and was the co-founder and president of Paddle8 from 2011 to 2018 when it was sold to The Native. Paddle8 is an online auction house for art and collectibles, described by "FT" as "reimagined art collecting for the digital age."


title: Alexander Gilkes

text: Gilkes is the son of Jeremy Gilkes, a dermatologist, and was born and raised in London. He was educated at Eton College and at the University of Bristol.


title: Alexander Gilkes

text: Gilkes has been based in New York since 2008. Prior to founding Squared Circles, he co-founded Paddle8 in 2011, which reported "$US140 million" in sales in 2015. Prior to that, Gilkes served as an auctioneer at Phillips de Pury & Company and worked at LVMH. Gilkes stepped down from his role at Paddle8 in 2018 when it was sold to The Native. In 2020, Gilkes co-founded venture studio Squared Circles along with Lukas Derksen and Paddle8 co-founder Osman Khan.


title: Alexander Gilkes

text: Gilkes has served as auctioneer for auctions including Madonna's Raising Malawi, Elton John AIDS Foundation and amFAR.


title: Alexander Gilkes

text: Gilkes "has been named" as one of "Fast Company's" Most Creative Entrepreneurs in 2017, the 100 Most Powerful People in the Art World ("Art + Auction") in 2014, 2015 and 2016, a Digital Maverick ("DETAILS"), one of the 40 Most Important People Under 40 ("Apollo") and appeared on "Vanity Fair" and "GQ's" best-dressed lists. He serves on the board of the New York Academy of Art.


title: Alexander Gilkes

text: Gilkes married fashion designer Misha Nonoo in Venice, Italy in May 2012. Their divorce was finalised in the summer of 2017.


title: Alexander Gilkes

text: Since 2018, Gilkes has been in a relationship with Russian former tennis player Maria Sharapova. They announced their engagement on 17 December 2020. Their son was born on 1 July 2022.


title: Chris Stein

text: Christopher Stein (born January 5, 1950) is an American musician known as the co-founder and guitarist of the new wave band Blondie. He is also a producer and performer for the classic soundtrack of the hip hop film "Wild Style", and writer of the soundtrack for the film "Union City", as well as an accomplished photographer.


title: Chris Stein

text: In 1973 Stein became the guitarist of the Stilettos and began a romantic relationship with Debbie Harry, one of the singers. In the summer of 1974 Stein, Harry, and the band's rhythm section left to start their own group which they eventually called Blondie. They soon became fixtures in the punk and new wave scene centered around CBGB and Max's Kansas City and by the end of the decade achieved international stardom. Blondie broke up in 1982 but reformed in 1997 and has been active off and on ever since. In addition to being the sole writer of the Blondie song "Sunday Girl", Stein co-wrote numerous hits with Harry, including "Heart of Glass", "Dreaming", "Island of Lost Souls", "Rapture", and "Rip Her to Shreds". Stein also ran the Animal Records label between 1982 and 1984.


title: Chris Stein

text: In 2015, Blondie members Debbie Harry and Chris Stein made a guest appearance alongside The Gregory Brothers in an episode of "Songify the News", and they collaborated again to parody the 2016 United States presidential election debates.


title: Chris Stein

text: A photographer, Stein documented the early New York City punk music scene, the visual allure of Debbie Harry and Blondie, and his collaborations with artists including Andy Warhol and H.R. Giger. Stein's photography was published most recently in September 2014 by Rizzoli in his book, "Chris Stein / Negative: Me, Blondie, and the Advent of Punk".


title: Chris Stein

text: The book "Negative: Me, Blondie and the Advent of Punk" was launched with an exhibition at Somerset House in London, which also coincided with the fortieth anniversary of the formation of Blondie. Some of the photographs in "Negative" have also been published in the Debbie Harry, Chris Stein and Victor Bockris co-authored volume "Making Tracks: The Rise of Blondie", first published by Elm Tree, London (1982). "Making Tracks" was later reissued by Da Capo, New York (1998).


title: Chris Stein

text: Stein's photography has also been shown in an exhibition at the Morrison Hotel Gallery, West Hollywood in August 2013; in a joint exhibition with Eddie Duggan at the University of Suffolk (April–May 2017), entitled "A la recherche du punk perdu", and in an exhibition in a Blondie 'pop-up' shop in London's Camden Market, linked to the 2017 Blondie performance at the Roundhouse.


title: Chris Stein

text: Stein was born to Jewish parents in Brooklyn, New York. He grew up in the Midwood section of Brooklyn, and attended Midwood High School in Brooklyn, but was expelled for wearing long hair. In 1983, Stein was diagnosed with pemphigus vulgaris, a rare autoimmune disease of the skin. He was cared for by his then-partner Debbie Harry and he has since regained normal function. Stein had developed a mild form of the disease, and was able to control it with a program of steroids. Stein was co-host of "TV Party", a public-access television cable TV show in New York City, that ran from 1978 to 1982.


title: Chris Stein

text: While in Blondie, Stein and Harry maintained a romantic relationship but never married. In 1985, the couple went their separate ways but have continued to work together on a professional basis. In 1999, Stein married actress Barbara Sicuranza, with whom he has two daughters, Akira and Valentina.


title: Chris Stein

text: Stein hasn't toured with Blondie since 2018 due to heart issues, but remains an active recording member in subsequent releases, as in "Blondie: Vivir en La Habana" (2019) and an upcoming to be released Blondie album. About his health condition, he stated: "I've been dealing with a dumbass condition called Atrial Fibrillation or AFib which is irregular heartbeats and combined with the meds I take for it I'm too fatigued to deal," Stein said. Former Sex Pistols bassist Glen Matlock will be filling in for Stein.


title: Eight queens puzzle

text: The eight queens puzzle is the problem of placing eight chess queens on an 8×8 chessboard so that no two queens threaten each other; thus, a solution requires that no two queens share the same row, column, or diagonal. There are 92 solutions. The problem was first posed in the mid-19th century. In the modern era, it is often used as an example problem for various computer programming techniques.


title: Eight queens puzzle

text: The eight queens puzzle is a special case of the more general "n" queens problem of placing "n" non-attacking queens on an "n"×"n" chessboard. Solutions exist for all natural numbers "n" with the exception of "n" = 2 and "n" = 3. Although the exact number of solutions is only known for "n" ≤ 27, the asymptotic growth rate of the number of solutions is (0.143 "n").


title: Eight queens puzzle

text: Chess composer Max Bezzel published the eight queens puzzle in 1848. Franz Nauck published the first solutions in 1850. Nauck also extended the puzzle to the "n" queens problem, with "n" queens on a chessboard of "n"×"n" squares.


title: Eight queens puzzle

text: Since then, many mathematicians, including Carl Friedrich Gauss, have worked on both the eight queens puzzle and its generalized "n"-queens version. In 1874, S. Gunther proposed a method using determinants to find solutions. J.W.L. Glaisher refined Gunther's approach.


title: Eight queens puzzle

text: In 1972, Edsger Dijkstra used this problem to illustrate the power of what he called structured programming. He published a highly detailed description of a depth-first backtracking algorithm.


title: Eight queens puzzle

text: The problem of finding all solutions to the 8-queens problem can be quite computationally expensive, as there are 4,426,165,368 possible arrangements of eight queens on an 8×8 board, but only 92 solutions. It is possible to use shortcuts that reduce computational requirements or rules of thumb that avoids brute-force computational techniques. For example, by applying a simple rule that chooses one queen from each column, it is possible to reduce the number of possibilities to 16,777,216 (that is, 8) possible combinations. Generating permutations further reduces the possibilities to just 40,320 (that is, 8!), which can then be checked for diagonal attacks.


title: Eight queens puzzle

text: The eight queens puzzle has 92 distinct solutions. If solutions that differ only by the symmetry operations of rotation and reflection of the board are counted as one, the puzzle has 12 solutions. These are called "fundamental" solutions; representatives of each are shown below.


title: Eight queens puzzle

text: A fundamental solution usually has eight variants (including its original form) obtained by rotating 90, 180, or 270° and then reflecting each of the four rotational variants in a mirror in a fixed position. However, one of the 12 fundamental solutions (solution 12 below) is identical to its own 180° rotation, so has only four variants (itself and its reflection, its 90° rotation and the reflection of that). Such solutions have only two variants (itself and its reflection). Thus, the total number of distinct solutions is 11×8 + 1×4 = 92.


title: Eight queens puzzle

text: Solution 10 has the additional property that no three queens are in a straight line. Solutions 1 and 8 have a 4-queen line.


title: Eight queens puzzle

text: Brute-force algorithms to count the number of solutions are computationally manageable for , but would be intractable for problems of , as 20! = 2.433 × 10. If the goal is to find a single solution, one can show solutions exist for all "n" ≥ 4 with no search whatsoever.


title: Eight queens puzzle

text: The examples above can be obtained with the following formulas. Let ("i", "j") be the square in column "i" and row "j" on the "n" × "n" chessboard, "k" an integer.


title: Eight queens puzzle

text: There is no known formula for the exact number of solutions for placing "n" queens on an board i.e. the number of independent sets of size "n" in an queen's graph. The 27×27 board is the highest-order board that has been completely enumerated. The following tables give the number of solutions to the "n" queens problem, both fundamental and all , for all known cases.


title: Eight queens puzzle

text: In 2021, Michael Simkin proved that for large numbers "n", the number of solutions of the "n" queens problem is approximately formula_1. More precisely, the number formula_2 of solutions has asymptotic growth


title: Eight queens puzzle

text: where formula_4 is a constant that lies between 1.939 and 1.945. (Here "o"(1) represents little o notation.)


title: Eight queens puzzle

text: If one instead considers a toroidal chessboard (where diagonals "wrap around" from the top edge to the bottom and from the left edge to the right), it is only possible to place "n" queens on an formula_5 board if formula_6 In this case, the asymptotic number of solutions is


title: Eight queens puzzle

text: Find the number of non-attacking queens that can be placed in a "d"-dimensional chess of size "n". More than "n" queens can be placed in some higher dimensions (the smallest example is four non-attacking queens in a 3×3×3 chess space), and it is in fact known that for any "k", there are higher dimensions where "n" queens do not suffice to attack all spaces.


title: Eight queens puzzle

text: On an 8×8 board one can place 32 knights, or 14 bishops, 16 kings or eight rooks, so that no two pieces attack each other. In the case of knights, an easy solution is to place one on each square of a given color, since they move only to the opposite color. The solution is also easy for rooks and kings. Sixteen kings can be placed on the board by dividing it into 2-by-2 squares and placing the kings at equivalent points on each square. Placements of "n" rooks on an "n"×"n" board are in direct correspondence with order-"n" permutation matrices.


title: Eight queens puzzle

text: Related problems can be asked for chess variations such as shogi. For instance, the "n"+"k" dragon kings problem asks to place "k" shogi pawns and "n"+"k" mutually nonattacking dragon kings on an "n"×"n" shogi board.


title: Eight queens puzzle

text: Pólya studied the "n" queens problem on a toroidal ("donut-shaped") board and showed that there is a solution on an "n"×"n" board if and only if "n" is not divisible by 2 or 3. In 2009 Pearson and Pearson algorithmically populated three-dimensional boards ("n"×"n"×"n") with "n" queens, and proposed that multiples of these can yield solutions for a four-dimensional version of the puzzle.


title: Eight queens puzzle

text: Given an "n"×"n" board, the domination number is the minimum number of queens (or other pieces) needed to attack or occupy every square. For "n" = 8 the queen's domination number is 5.


title: Eight queens puzzle

text: Variants include mixing queens with other pieces; for example, placing "m" queens and "m" knights on an "n"×"n" board so that no piece attacks another or placing queens and pawns so that no two queens attack each other.


title: Eight queens puzzle

text: In 1992, Demirörs, Rafraf, and Tanik published a method for converting some magic squares into "n"-queens solutions, and vice versa.


title: Eight queens puzzle

text: In an "n"×"n" matrix, place each digit 1 through "n" in "n" locations in the matrix so that no two instances of the same digit are in the same row or column.


title: Eight queens puzzle

text: Consider a matrix with one primary column for each of the "n" ranks of the board, one primary column for each of the "n" files, and one secondary column for each of the 4"n" − 6 nontrivial diagonals of the board. The matrix has "n" rows: one for each possible queen placement, and each row has a 1 in the columns corresponding to that square's rank, file, and diagonals and a 0 in all the other columns. Then the "n" queens problem is equivalent to choosing a subset of the rows of this matrix such that every primary column has a 1 in precisely one of the chosen rows and every secondary column has a 1 in at most one of the chosen rows; this is an example of a generalized exact cover problem, of which sudoku is another example.


title: Eight queens puzzle

text: The completion problem asks whether, given an "n"×"n" chessboard on which some queens are already placed, it is possible to place a queen in every remaining row so that no two queens attack each other. This and related questions are NP-complete and #P-complete.


title: Eight queens puzzle

text: Finding all solutions to the eight queens puzzle is a good example of a simple but nontrivial problem. For this reason, it is often used as an example problem for various programming techniques, including nontraditional approaches such as constraint programming, logic programming or genetic algorithms. Most often, it is used as an example of a problem that can be solved with a recursive algorithm, by phrasing the "n" queens problem inductively in terms of adding a single queen to any solution to the problem of placing "n"−1 queens on an "n"×"n" chessboard. The induction bottoms out with the solution to the 'problem' of placing 0 queens on the chessboard, which is the empty chessboard.


title: Eight queens puzzle

text: This technique can be used in a way that is much more efficient than the naïve brute-force search algorithm, which considers all 64 = 2 = 281,474,976,710,656 possible blind placements of eight queens, and then filters these to remove all placements that place two queens either on the same square (leaving only 64!/56! = 178,462,987,637,760 possible placements) or in mutually attacking positions. This very poor algorithm will, among other things, produce the same results over and over again in all the different permutations of the assignments of the eight queens, as well as repeating the same computations over and over again for the different sub-sets of each solution. A better brute-force algorithm places a single queen on each row, leading to only 8 = 2 = 16,777,216 blind placements.


title: Eight queens puzzle

text: One algorithm solves the eight rooks puzzle by generating the permutations of the numbers 1 through 8 (of which there are 8! = 40,320), and uses the elements of each permutation as indices to place a queen on each row.


title: Eight queens puzzle

text: The backtracking depth-first search program, a slight improvement on the permutation method, constructs the search tree by considering one row of the board at a time, eliminating most nonsolution board positions at a very early stage in their construction.


title: Eight queens puzzle

text: Because it rejects rook and diagonal attacks even on incomplete boards, it examines only 15,720 possible queen placements.


title: Eight queens puzzle

text: An alternative to exhaustive search is an 'iterative repair' algorithm, which typically starts with all queens on the board, for example with one queen per column. It then counts the number of conflicts (attacks), and uses a heuristic to determine how to improve the placement of the queens. The 'minimum-conflicts' heuristic – moving the piece with the largest number of conflicts to the square in the same column where the number of conflicts is smallest – is particularly effective: it easily finds a solution to even the 1,000,000 queens problem.


title: Eight queens puzzle

text: Unlike the backtracking search outlined above, iterative repair does not guarantee a solution: like all greedy procedures, it may get stuck on a local optimum. (In such a case, the algorithm may be restarted with a different initial configuration.) On the other hand, it can solve problem sizes that are several orders of magnitude beyond the scope of a depth-first search.


title: Eight queens puzzle

text: As an alternative to backtracking, solutions can be counted by recursively enumerating valid partial solutions, one row at a time. Rather than constructing entire board positions, blocked diagonals and columns are tracked with bitwise operations. This does not allow the recovery of individual solutions.


title: Eight queens puzzle

text: The following program is a translation of Niklaus Wirth's solution into the Python programming language, but does without the index arithmetic found in the original and instead uses lists to keep the program code as simple as possible. By using a coroutine in the form of a generator function, both versions of the original can be unified to compute either one or all of the solutions. Only 15,720 possible queen placements are examined.


title: Root canal treatment

text: Root canal treatment (also known as endodontic therapy, endodontic treatment, or root canal therapy) is a treatment sequence for the infected pulp of a tooth which is intended to result in the elimination of infection and the protection of the decontaminated tooth from future microbial invasion. Root canals, and their associated pulp chamber, are the physical hollows within a tooth that are naturally inhabited by nerve tissue, blood vessels and other cellular entities. Together, these items constitute the dental pulp.


title: Root canal treatment

text: Endodontic therapy involves the "removal" of these structures, disinfection and the subsequent shaping, cleaning, and decontamination of the hollows with small files and irrigating solutions, and the "obturation" (filling) of the decontaminated canals. Filling of the cleaned and decontaminated canals is done with an inert filling such as gutta-percha and typically a zinc oxide eugenol-based cement. Epoxy resin is employed to bind gutta-percha in some root canal procedures. Another option is to use an antiseptic filling material containing paraformaldehyde like N2. Endodontics includes both primary and secondary endodontic treatments as well as periradicular surgery which is generally used for teeth that still have potential for salvage.


title: Root canal treatment

text: The procedure is often complicated, depending on circumstances, and may involve multiple visits over a period of weeks.


title: Root canal treatment

text: Before endodontic therapy is carried out, a correct diagnosis of the dental pulp and the surrounding periapical tissues is required. This allows the endodontist to choose the most appropriate treatment option, allowing preservation and longevity of the tooth and surrounding tissues. Treatment options for an irreversibly inflamed pulp (irreversible pulpitis) include either extraction of the tooth or removal of the pulp.


title: Root canal treatment

text: Removing the infected/inflamed pulpal tissue enables the endodontist to help preserve the longevity and function of the tooth. The treatment option chosen involves taking into account the expected prognosis of the tooth, as well as the patient's wishes. A full history is required (which includes the patient's symptoms and medical history), along with a clinical examination (both inside and outside the mouth), and the use of diagnostic tests.


title: Root canal treatment

text: There are several diagnostic tests that can aid in the diagnosis of the dental pulp and the surrounding tissues.


title: Root canal treatment

text: If a tooth is considered so threatened (because of decay, cracking, etc.) that future infection is considered very likely or inevitable, a pulpectomy (removal of the pulp tissue) is advisable to prevent such infection. Usually, some inflammation and/or infection is already present within and/or below the tooth. To cure the infection and save the tooth, the dentist drills into the pulp chamber and removes the infected pulp. To eliminate bacteria from the pulp chamber and root canals, the use of efficient antiseptics and disinfectants is necessary. The soft tissues are either drilled out of the root canal(s) with engine driven rotary files, or with long needle-shaped hand instruments known as hand files (H files and K files).


title: Root canal treatment

text: The dentist makes an opening through the enamel and dentin tissues of the tooth, usually using a dental drill fitted with a dental burr.


title: Root canal treatment

text: The use of a rubber dam for tooth isolation is mandatory in endodontic treatment for several reasons:


title: Root canal treatment

text: There have been a number of progressive iterations to the mechanical preparation of the root canal for endodontic therapy. The first, referred to as the "standardized technique", was developed by Ingle in 1961, and had disadvantages such as the potential for loss of working length and inadvertent ledging, zipping or perforation. Subsequent refinements have been numerous, and are usually described as "techniques". These include the step-back, circumferential filing, incremental, anticurvature filing, step-down, double flare, crown-down-pressureless, balanced force, canal master, apical box, progressive enlargement, modified double flare, passive stepback, alternated rotary motions, and apical patency techniques.


title: Root canal treatment

text: The step back technique, also known as telescopic or serial root canal preparation, is divided in two phases: in the first, the working length is established and then the apical part of the canal is delicately shaped since a size 25 K-file reaches the working length; in the second, the remaining canal is prepared with manual or rotating instrumentation. This procedure, however, has some disadvantages, such as the potential for inadvertent apical transportation. Incorrect instrumentation length can occur, which can be addressed by the modified step back. Obstructing debris can be dealt with by the passive step back technique. The crown down is a procedure in which the dentist prepares the canal beginning from the coronal part after exploring the patency of the whole canal with the master apical file.


title: Root canal treatment

text: There is a hybrid procedure combining step back and crown down: after the canal's patency check, the coronal third is prepared with hand or Gates Glidden drills, then the working length is determined and finally the apical portion is shaped using step back techniques. The double flare is a procedure introduced by Fava where the canal is explored using a small file. Then canal is prepared in crown down manner using K-files then follows a "step back" preparation with 1 mm increments with increasing file sizes. With early coronal enlargement, also described as "three times technique", apical canals are prepared after a working length assessment using an apex locator; then progressively enlarged with Gates Glidden drills (only coronal and middle third). For the eponymic third time the dentist "arrives at the apex" and, if necessary, prepares the foramen with a size 25 K-file; the last phase is divided in two refining passages: the first with a 1-mm staggered instrument, the second with 0.5-mm staggering. From the early nineties engine-driven instrumentation were gradually introduced including the ProFile system, the Greater Taper files, the ProTaper files, and other systems like Light Speed, Quantec, K-3 rotary, Real World Endo, and the Hero 642.


title: Root canal treatment

text: All of these procedures involve frequent irrigation and recapitulation with the master apical file, a small file that reaches the apical foramen. High frequency ultrasound based techniques have also been described. These can be useful in particular for cases with complex anatomy, or for retained foreign body retrieval from a failed prior endodontic procedure.


title: Root canal treatment

text: There are two slightly different anti-curvature techniques. In the balanced forces technique, the dentist inserts a file into the canal and rotates clockwise a quarter of a turn, engaging dentin, then rotates counter-clockwise half/ three-quarter of a revolution, applying pressure in an apical direction, shearing off tissue previously meshed. From the balanced forces stem two other techniques: the reverse balanced force (where GT instruments are rotated first anti-clockwise and then clockwise) and the gentler "feed and pull" where the instrument is rotated only a quarter of a revolution and moved coronally after an engagement, but not drawn out.


title: Root canal treatment

text: As of 2018, novocaine is most commonly used in dental procedures to numb the area around a tooth. More novocaine is required for a root canal treatment than for a simple filling.


title: Root canal treatment

text: The primary aim of chemical irrigation is to kill microbes and dissolve pulpal tissue. Certain irrigants, such as sodium hypochlorite and chlorhexidine, have proved to be effective antimicrobials in vitro and are widely used during root canal therapy worldwide. According to a systematic review, however, there is a lack of good quality evidence to support the use of one irrigant over another in terms of both short and long term prognosis of therapy.


title: Root canal treatment

text: Root canal irrigation systems are divided into two categories: manual agitation techniques and machine-assisted agitation techniques. Manual irrigation includes positive-pressure irrigation, which is commonly performed with a syringe and a side vented needle. Machine-assisted irrigation techniques include sonics and ultrasonics, as well as newer systems which deliver apical negative-pressure irrigation.


title: Root canal treatment

text: The standard filling material is gutta-percha, a natural polymer prepared from latex from the percha tree ("Palaquium gutta"). The standard endodontic technique involves inserting a gutta-percha cone (a "point") into the cleaned-out root canal along with a sealing cement. Another technique uses melted or heat-softened gutta-percha which is then injected or pressed into the root canal passage(s). However, since gutta-percha shrinks as it cools, thermal techniques can be unreliable and sometimes a combination of techniques is used. Gutta-percha is radiopaque, allowing verification afterwards that the root canal passages have been completely filled and are without voids.


title: Root canal treatment

text: Pain control can be difficult to achieve at times because of anesthetic inactivation by the acidity of the abscess around the tooth apex. Sometimes the abscess can be drained, antibiotics prescribed, and the procedure reattempted when inflammation has been mitigated. The tooth can also be unroofed to allow drainage and help relieve pressure.


title: Root canal treatment

text: A root treated tooth may be eased from the occlusion as a measure to prevent tooth fracture prior to the cementation of a crown or similar restoration. Sometimes the dentist performs preliminary treatment of the tooth by removing all of the infected pulp of the tooth and applying a dressing and temporary filling to the tooth. This is called a pulpectomy. The dentist may also remove just the coronal portion of the dental pulp, which contains 90% of the nerve tissue, and leave intact the pulp in the canals. This procedure, called a "pulpotomy", tends to essentially eliminate all the pain. A pulpotomy may be a relatively definitive treatment for infected primary teeth. The pulpectomy and pulpotomy procedures aim to eliminate pain until the follow-up visit for finishing the root canal procedure. Further occurrences of pain could indicate the presence of continuing infection or retention of vital nerve tissue.


title: Root canal treatment

text: Some dentists may decide to temporarily fill the canal with calcium hydroxide paste in order to thoroughly sterilize the site. This strong base is left in place for a week or more to disinfect and reduce inflammation in surrounding tissue, requiring the patient to return for a second or third visit to complete the procedure. There appears to be no benefit from this multi-visit option, however, and single-visit procedures actually show better (though not statistically significant) patient outcomes than multi-visit ones.


title: Root canal treatment

text: A temporary filling material is applied between the visits. Leaky temporary filling will allow the root canals to become reinfected by bacteria in the saliva (coronal microleakage). Khayat et al. showed that all root canals obturated with gutta-percha and root canal sealer using either lateral or vertical condensation were recontaminated in less than 30 days when exposed to saliva. Therefore, maintaining a coronal seal throughout root canal therapy is very important for the success of the treatment.


title: Root canal treatment

text: Molars and premolars that have had root canal therapy should be protected with a crown that covers the cusps of the tooth. This is because the access made into the root canal system removes a significant amount of tooth structure. Molars and premolars are the primary teeth used in chewing and will almost certainly fracture in the future without cuspal coverage. Anterior teeth typically do not require full coverage restorations after a root canal procedure, unless there is extensive tooth loss from decay or for esthetics or unusual occlusion. Placement of a crown or cusp-protecting cast gold covering is recommended also because these have the best ability to seal the treated tooth. There is insufficient evidence to assess the effects of crowns compared to conventional fillings for the restoration of root-filled teeth, decision of restoration should rely on the clinical experience of the practitioner and the preference of the patients. If the tooth is not perfectly sealed, the canal may leak, causing eventual failure. A tooth with a root canal treatment still has the ability to decay, and without proper home care and an adequate fluoride source the tooth structure can become severely decayed (often without the patient's knowledge since the nerve has been removed, leaving the tooth without any pain perception). Thus, non-restorable carious destruction is the main reason for extraction of teeth after root canal therapy, accounting for up to two-thirds of these extractions. Therefore, it is very important to have regular X-rays taken of the root canal to ensure that the tooth is not having any problems that the patient would not be aware of.


title: Root canal treatment

text: Endodontic treatment may fail for many reasons: one common reason for failure is inadequate chemomechanical debridement of the root canal. This may be due to poor endodontic access, missed anatomy or inadequate shaping of the canal, particularly in the apical third of the root canal, also due to the difficulty of reaching the accessory canals which are minute canals that extend in from the pulp to the periodontium in a random direction. They are mostly found in the apical third of the root.


title: Root canal treatment

text: Exposure of the obturation material to the oral environment may mean the gutta-percha is contaminated with oral bacteria. If complex and expensive restorative dentistry is contemplated then ideally the contaminated gutta percha would be replaced in a retreatment procedure to minimise the risk of failure.


title: Root canal treatment

text: The type of bacteria found within a failed canal may differ from the normal infected tooth. Enterococcus faecalis and/or other facultative enteric bacteria or Pseudomonas sp. are found in this situation.


title: Root canal treatment

text: Endodontic retreatment is technically demanding; it can be a time-consuming procedure, as meticulous care is required by the dentist. Retreatment cases are typically referred to a specialist endodontist. Use of an operating microscope or other magnification may improve outcomes.


title: Root canal treatment

text: Currently, there is no strong evidence favoring surgical or non-surgical retreatment of periapical lesions. However, studies have reported that patients experience more pain and swelling after surgical retreatment compared to non-surgical. When comparing surgical techniques, the use of ultrasonic devices may improve healing after retreatment. Application of nanomotor implants have been proposed to achieve thorough disinfection of the dentine. There is no evidence that the use of antibiotics after endodontic retreatment prevents post-operative infection.


title: Root canal treatment

text: Since 2000 there have been great innovations in the art and science of root canal therapy. Dentists now must be educated on the current concepts in order to optimally perform a root canal procedure. Root canal therapy has become more automated and can be performed faster thanks in part to machine-driven rotary technology and more advanced root canal filling methods. Many root canal procedures are done in one dental visit which may last for around 1–2 hours. Newer technologies are available (e.g. cone-beam CT scanning) that allow more efficient, scientific measurements to be taken of the dimensions of the root canal, however, the use of CT scanning in endodontics has to be justified. Many dentists use dental loupes to perform root canal therapy, and the consensus is that procedures performed using loupes or other forms of magnification (e.g. a surgical microscope) are more likely to succeed than those performed without them. Although general dentists are becoming versed in these advanced technologies, they are still more likely to be used by root canal specialist (known as endodontists).


title: Root canal treatment

text: Laser root canal procedures are a controversial innovation. Lasers may be fast but have not been shown to thoroughly disinfect the whole tooth, and may cause damage to the tooth.


title: Root canal treatment

text: Several randomized clinical trials concluded that the use of rotary instruments is associated with a lower incidence of pain following the endodontic procedure when compared to the use of manual hand instruments. Corticosteroid intra-oral injections were found to alleviate pain in the first 24 hours in patients with symptomatic irreversible pulp inflammation.


title: Root canal treatment

text: Instruments may separate (break) during root canal treatment, meaning a portion of the metal file used during the procedure remains inside the tooth. The file segment may be left behind if an acceptable level of cleaning and shaping has already been completed and attempting to remove the segment would risk damage to the tooth. While potentially disconcerting to the patient, having metal inside of a tooth is relatively common, such as with metal posts, amalgam fillings, gold crowns, and porcelain fused to metal crowns. The occurrence of file separation depends on the narrowness, curvature, length, calcification and number of roots on the tooth being treated. Complications resulting from incompletely cleaned canals, due to blockage from the separated file, can be addressed with surgical root canal treatment. To minimise the risk of endodontic files fracturing:


title: Root canal treatment

text: A sodium hypochlorite incident is an immediate reaction of severe pain, followed by edema, haematoma and ecchymosis, as a consequence of the solution escaping the confines of the tooth and entering the periapical space. This may be caused iatrogenically by binding or excessive pressure on the irrigant syringe or it may occur if the tooth has an unusually large apical foramen. It is usually self-resolving and may take two to five weeks to fully resolve.


title: Root canal treatment

text: Tooth discoloration is common following root canal treatment; however, the exact causes for this are not completely understood. Failure to completely clean out the necrotic soft tissue of the pulp system may cause staining, and certain root canal materials (e.g. gutta percha and root canal sealer cements) can also cause staining. Another possible factor is that the lack of pulp pressure in dentinal tubules once the pulp is removed leads to incorporation of dietary stains in dentin.


title: Root canal treatment

text: Another common complication of root canal therapy is when the entire length of the root canal is not completely cleaned out and filled (obturated) with root canal filling material (usually gutta percha). On the other hand, the root canal filling material may be extruded from the apex leading to other complications. The X-ray in the right margin shows two adjacent teeth that had received bad root canal therapy. The root canal filling material (3, 4, and 10) does not extend to the end of the tooth roots (5, 6 and 11). The dark circles at the bottom of the tooth roots (7 and 8) indicated infection in the surrounding bone. Recommended treatment is either to redo the root canal therapy or extract the tooth and place dental implants. Poor quality filling material or sealant may also cause root canal treatment to fail.


title: Root canal treatment

text: Root-canal-treated teeth may fail to heal—for example, if the dentist does not find, clean and fill all of the root canals within a tooth. On a maxillary molar, there is more than a 50% chance that the tooth has four canals instead of just three, but the fourth canal, often called a "mesio-buccal 2", tends to be very difficult to see and often requires special instruments and magnification in order to see it (most commonly found in first maxillary molars; studies have shown an average of 76% up to 96% of such teeth with the presence of an MB2 canal). This infected canal may cause a continued infection or "flare-up" of the tooth. Any tooth may have more canals than expected, and these canals may be missed when the root canal procedure is performed. Sometimes canals may be unusually shaped, making them impossible to clean and fill completely; some infected material may remain in the canal. Sometimes the canal filling does not fully extend to the apex of the tooth, or it does not fill the canal as densely as it should. Sometimes a tooth root may be perforated while the root canal is being treated, making it difficult to fill the tooth. The perforation may be filled with a root repair material, such as one derived from natural cement called mineral trioxide aggregate (MTA). A specialist can often re-treat failing root canals, and these teeth will then heal, often years after the initial root canal procedure.


title: Root canal treatment

text: However, the survival or functionality of the endodontically treated tooth is often the most important aspect of endodontic treatment outcomes, rather than apical healing alone.