Process for minimal time tooth capping

A method for making caps of eight different sizes for each of a persons teeth allows premaking caps that will fit almost any tooth of any patient; caps are preferably prepared from a commercially available quartz or silicon dioxide filled acrylic material called Artglass r; the caps allow curing a material such as Charisma r with ultraviolet light thereby allowing a practitioner to place a cap containing Charisma r over a tooth prepared for capping; settle the cap in place; remove any excess and expose the capped tooth with a ultraviolet light for about three minutes to form a solidly capped tooth in one visit to the practitioners office.

BACKGROUND OF THE INVENTION 
Huge strides have been made in the field of dentistry and tooth care since 
George Washington reportedly used wooden pegs for a tooth replacement. 
Currently capping or putting crowns on teeth require the dentist to grind 
the tooth to remove decay and to grind to a relatively small flat top 
pyramid shape to receive a made to-order crown. A temporary material is 
then used to protect the tooth for the two or more days usually required 
to make the needed new crown or cap. 
This invention addresses the problem as outlined and provides the dentist 
with a way to cap a tooth with a single visit to the dentist's office. 
Filled, light polymerizable plastics with special properties to simulate 
or improve on properties of a natural tooth make this improvement 
possible. The presently preferred material for the outer shell or cap is 
known as ARTGLASS r developed in 1995. Artglass r is available from 
Heraeus Kulzer Inc.Co.,Dental Lab Division, Muirlands Blvd., Irvine, 
Calif. 92618-2595. ARTGLASS r is a light polymerizable multifunctional 
methacrylate monomer capable of forming a highly crosslinked three 
dimensional molecular network and filled with about 20% glass particles of 
about a two micrometer size and about 55% of glass particles of about 
seven tenths micrometer size. With filling of this size the surface is 
sufficiently smooth as to have a lustrous appearance. When light cured or 
polymerized the cured material is harder, has more fracture resistance, 
and is more abrasion resistant than any of the ceramics or hybrid 
composites normally used for crowns or bridges. The preferred light 
polymerizable material for use inside the cap when the cap is fabricated 
from ARTGLASS r is Charisma r. The Charisma r, also available from 
Hereaeous Kulzer Inc.,Co., is ultraviolet light curable inside the mouth 
in about three minutes. Charisma r is comprised of a multifunctional 
methacrylate monomer capable of forming a highly crosslinked three 
dimensional molecular network and filled with about 75% of glass particles 
of about seven tenths micrometer size. The properties of the cured 
Charisma r are essentially the same as the Artglass r. 
Tooth sizes vary in people but caps of about eight sizes for each tooth 
would allow capping of essentially all the teeth in the populace. 
Using a three piece glass or methacrylate polymer mold ARTGLASS r can be 
molded and light cured to form a cap approximately twenty five thousandths 
of an inch thick. With much less grinding than necessary for the presently 
used procedure a cap of one of the eight sizes will loosely fit over the 
tooth. The lesser grinding required is a special advantage in capping of 
childrens' teeth since in a child the nerve cavity is at a maximum size, 
leaving a lesser portion of the tooth that may be ground off to receive a 
normal cap. With a small amount of the uncured Charisma r placed in the 
cap the cap may be placed over the tooth and the cap may be settled in 
place by the patient biting down. The dentist may then remove any excess 
material forced out and using the light source cure the interior material 
to bond with the tooth and become integral with the cap or crown. 
The dentist may do minor grinding to get a perfect comfortable fit and may 
grind through the cap since the cap and Charisma r put in the cap have 
essentially the same cured properties. The Artglass r that forms the cap 
may be colored to match a patients tooth and Charisma r put in the cap may 
be also be colored to closely match the patients tooth since the cap is 
translucent. 
Molds for forming the caps of the polymerizable material such as Artglass r 
or similar material may be formed in glass or in a plastic that is 
transparent to the ultraviolet light that is necessary to cure the 
polymerizable material. 
The closest prior art that we have found is U.S. Pat. No. 5,192,207 dated 
Mar. 9, 1993, entitled "Composite Resin Crown, Replacement Tooth and 
Method" issued to Rosellini and U.S. Pat. No. 5,332,390 issued Jul. 26, 
1994 entitled "Shell Tooth Form" also issued to Rosellini. Our invention 
differs significantly in that: 
our shell is quartz or silicon dioxide filled to give wearability 
equivalent to porcelain whereas the transparent shell specified by 
Rosellini could not be filled with quartz or silicon dioxide and quite 
likely does not have equivalent wearability. A filling material to allow 
transparency would necessarily have the same refractive index as the 
polymerized polymer. Our preferred Artglass r material is filled with 
quartz particles of less than two micrometers in cross section and is 
translucent and has wearability essentially equal to porcelain. Our 
translucent cap will pass sufficient ultraviolet light to cure the 
Charisma r cap filler recommended in about three minutes curing time; 
with our invention grinding through the prepared cap is of little 
consequence since ultraviolet light cured Charisma r has wear properties 
similar to tooth enamel; 
in our system caps for eight sizes of each tooth are compression molded 
giving caps that will fit almost any tooth; 
our system differs from Rossellini in that our caps may be colored to match 
a patients teeth; 
our system is similar to Rosellini in that the Charisma r filling material 
may be colored to match existing teeth. 
SUMMARY OF THE INVENTION 
The invention encompasses making caps of eight different sizes for each 
tooth in a patients mouth. With eight sizes available for each tooth there 
will be a cap to fit almost any patients tooth. Caps are made of Artglass 
r, an acrylic plastic material filled with essentially round quartz 
particles of less than two micrometers in size and that when specially 
cured in an oven with a narrow ultraviolet light wavelength band has 
almost ideal properties for dental use and is translucent and allows 
normal ultraviolet light to pass through. Thus a practitioner may 
partially fill an Artglass r cap with an ultraviolet light curable 
material such as Charisma r; place this over a tooth prepared for capping, 
settle the cap in place by having the patient bite down, remove excess 
material and using ultraviolet light for about three minutes cure the 
Charisma r in place in the mouth to form a solidly capped tooth.

DETAILED DESCRIPTION OF THE INVENTION 
In FIG. 1 simple equipment for small volume formation or molding of caps is 
shown. Both the upper mold plate 1 and the split lower mold plate 3 are 
fabricated of material transparent to ultraviolet light such as glass or 
acrylate polymers since at present the commercially available material 
with the most desirable properties for this type of dental use is 
polymerizable or curable by use of ultraviolet light. In plate 1 male 
molds 4 are shown that may be precisely guided into female molds 5 in 
plate 3 with about twenty five thousandths of an inch clearance in order 
to form a cap with about a twenty five thousandths of an inch sidewall. 
Male mold 6 on plate 1 is about fifty thousandths of an inch larger than 
the metal post normally used for a jaw mounted replacement tooth. Female 
molds 5 may be sculptured to form a replacement tooth of any size and 
shape desired . The dentist may do minor necessary shaping to give exact 
match and fit for the replacement tooth. 
FIG. 2 shows the female mold 3 split in the middle to allow removal of a 
properly shaped tooth cap that is normally larger at the top than at the 
bottom. No.'s 5 are tops of molds for differing size teeth. 
In FIG. 3 shape of normal teeth 2 are indicated as shown projecting below 
the gum line 10 with a dotted line 7 indicating the amount of tooth that 
must be ground away in order to put the normal crown or cap on the tooth. 
In FIG. 4 a crown 9 is shown fitted over the tooth stub 7 after crown 9 has 
been formed to the exact shape of the previously existing tooth. This 
manufacture takes some two or three days while the patient is fitted with 
some uncomfortable temporary crown. The bulky shape of the crown 9 is 
necessary to get sufficient strength for normal use. 
FIG. 5 shows the thinner cap of our invention with the lesser grinding to 
prepare tooth 12 with area 13 indicating a spot where decay has been 
removed. This spot would be filled by material 16 such as Charisma r and 
cured to become an integral part of the cap 14. 
FIG. 6 shows a tooth replacement pivot 13 that is fastened to the jawbone 
11 with post 15 that is normally metal. In our system a fully formed tooth 
as indicated in one of the mold forms in FIG. 1 may be slipped over post 
15 and with a very small amount of material such as indicated in 16, FIG. 
5 integrally held in place. 
FIG. 7 shows a measuring and dispensing unit 24 to measure the 
unpolymerized material to make caps or put into cap interiors as 
discussed. Plunger 20 is threaded through cap 22 since the filled 
unpolymerized material is quite viscous. Calibration marks 26 are used to 
indicate the amount of material expressed.