bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface ultrastructure of some oral bacteria
Authors: KELSTRUP J. , THEILADE J. , FEJERSKOV O.
Published: October 2007

Abstract – Adhesion of Streptococcus sanguis, Fusobacterium nucleatum and an Actinomyces sp. to enamel and epon and their interspecies cohesion was studied with scanning and transmission electron microscopy. For adhesion studies enamel or epon was coated with salivary macromolecules and then cells of S. sanguis and in some experiments also with F. nucleatum or Actinomyces sp. Cells of S. sanguis were seen scattered over the surface of a thin “pellicle” that was heavily stained, and F. nucleatum and Actinomyces sp. adhered to S. sanguis or directly to the “pellicle”. For studies of cohesion S. sanguis was brought to cohere with F. nucleatum or Actinomyces sp. and then processed for transmission electron microscopy. The morphology of the cell surface structures involved was studied in negatively stained preparations or in thin sections of material treated with ruthenium red or poststained with uranyl and lead salts, phosphotungstic acid or periodic acid‐thiocarbohydrazide‐osmium tetroxide. S. sanguis demonstrated a fuzzy coat of fimbriae that seemed to unfold in areas of contact with other cells, while cells of F. nucleatum had 6–10 polar pilus‐like fimbriae, which appeared to be instrumental in cohesion, as did a dense coat of long, slender fimbriae that covered cells of Actinomyces sp.
Denture stomatitis with multiple intramucosal fistulae
Authors: SCHIØDT M.
Published: October 2007

Abstract – A hitherto undescribed clinical and histologic entity occurring in the palate of 13 denture‐wearing patients is described. Clinically it is characterized by the presence of small yellowish areas in the hard palate, which on pressure yield a whitish creamy material through multiple openings. The surrounding mucosa may exhibit various degrees of erythema. The histologic changes are characterized by the presence of intramucosal fistulae lined with unkeratinized squamous epithelium. The content of the fistulae, which corresponds to the creamy material expelled, consists of desquamated epithelial cells. These changes have mostly been nodced in elderly females, all wearing maxillary dentures for many years. This entiPf is considered a type of demure stomatitis characterized by intramucosal proliferation of epithelium, possibly because of long‐standing chronic irritation from dentures. The origin of the intramucosal fistulae is unknown. The fistulae are believed to originate either from the ductus of the minor salivary glands or from the surface epithelium of the palate.
Die‐spacing technique by diffusion precipitation
Authors: JØRGENSEN KNUD DREYER , FINGER WERNER
Published: October 2007

Abstract – The present study has shown that it is possible by utilizing the principle of diffusion to precipitate on stone dies an adequate resin spacer of uniform and desirable thickness. Details and variables of the technique are described. The precipitation technique is simple and requires a minimum of time and equipment. This spacer technique opens up gateways for a new and improved casting technique cleared of most of the variables affecting the precision of the methods employed up till now. A new gypsum bonded investment for the new casting technique is being developed.
Quantitative evaluation of the morphology of the inner surface of composite restorations
Authors: QVIST VIBEKE , QVIST JØRGEN
Published: October 2007

Abstract –

The aim of the present study was to develop a method for quantitative evaluation of the morphology of inner surfaces of composite resin restorations. Twelve restorations made In vivo using the acid etch technique were examined in a scanning electron microscope at a magnification of × 2000. 2500 predetermined areas (6300 μm2 each) on the inner surfaces of the fillings were scored from 0 to 3 with respect to the impression of their rendering of morphologic details from the etched cavity walls. Based on all the scorings and parts of the scorings, estimates for the enamel and for the dentin relief on each of the fillings were calculated. The statistical comparison of these estimates showed that approximately 50 areas per filling might be scored to attain an objective and reliable quantitation of the surface morphology.
Reactions of the dental pulp to microbial provocation of calcium hydroxide treated dentin
Authors: BERGENHOLTZ GUNNAR , REIT CLAES
Published: October 2007

Abstract –

The purpose of the present study was to determine whether treatment of dentin with calcium hydroxide reduces pulp irritation caused by microbial products. The experiment was carried out in three young monkeys. Cavities were prepared on the buccal tooth surface deep into dentin of 62 teeth. Calcium hydroxide mixed with distilled water was placed in one group of cavities. A set of control cavities received treatment with saline soaked filter‐paper discs. The calcium hydroxide dressing and the saline discs were separated from the oral cavity for a period of 14 or 60 d by a Teflon disc and a layer of zinc oxide‐eugenol cement. At the end of these periods the content of each cavity was removed and substituted by lyophilized material from cultivated plaque bacteria. After 3 d of exposure the monkeys were killed and the teeth subjected to histologic treatment. Assessments made in the light microscope revealed that pulps subjacent to calcium hydroxide‐treated dentin in the majority of cases showed no or only slight infiltrates of inflammatory cells. In controls, 13 out of 22 pulps showed severe inflammatory cell infiltrates or total pulp tissue necrosis. It was concluded that treatment of dentin with calcium hydroxide may reduce the possibility for bacterial components to cause pulp tissue damage.
Effect of saliva stimulants (Hybrin® and malic acid) on cervical root surfaces in vitro
Authors: ANNEROTH GÖRAN , NORDENRAM GUNILLA , BENGTSSON SVEN
Published: October 2007

Abstract –

Two saliva stimulating drugs, solutions of Hybrin® and malic acid were in an in vitro study found to have a heavy demineralizing effect on the root surface of the dental hard tissue. Consequently the drugs cannot be recommended to patients suffering from dry mouth reaction.
An oral lichen planus‐like lesion in Indian betel‐tobacco chewers
Authors: DAFTARY D. K. , BHONSLE R. B. , MURTI R. B. , PINDBORG J. J. , MEHTA FALI S.
Published: October 2007

Abstract –

During an epidemiologic study of oral cancer and precancerous lesioms among Indian villagers, a lichen planus‐like lesion was observed in Kerala. The lesion consisted of white, wavy, parallel, non‐elevated lines that could, not be scraped off. The lesion occurred exclusively among chewers and at the site of placement of quid. There were no subjective symptoms. The peak prevalence of the 35 diagnosed lesions was in the 35‐44 years age‐group for males and 45‐54 for females. There was a marked female predominance. The histologic features were very similar to those seen in oral lichen planus.
Plaque inhibition and improved gingival condition by use of a stannous fluoride toothpaste
Authors: BAY INGER , RØLLA GUNNAR
Published: October 2007

Abstract –

The present study contains data from a 4‐week clinical study where the effect of an experimental toothpaste containing 0.4% SnF2 on plaque and gingivitis was tested in a group of teenagers. The study was performed according to a double‐blind, cross‐over design. It was shown that the SnF2 containing toothpaste reduced both plaque and gingivitis significantly compared to a placebo paste which contained no fluoride or stannous ions.
Some effects of bone meal and NaF tablets on the composition of saliva
Authors: RASMUSSEN PER , ESPELID IVAR , BJORVATN KJELL
Published: October 2007

Abstract –

Whole saliva was collected from dental students while: 1) chewing paraffin, 2) sucking bone meal tablets, and 3) sucking NaF tablets. Initial pH, content of ionized and total calcium and content of fluoride in saliva were measured. As compared to paraffin stimulated saliva, the sucking of bone meal tablets caused a decrease in salivary pH, ionized calcium and fluoride. Sucking NaF tablets caused a fall in initial pH and an increase in total calcium, while the amount of ionized calcium remained unchanged. The content of fluoride was high in saliva during sucking of NaF tablets.
Dissolution of bovine pulp tissue by endodontic solutions
Authors: KOSKINEN KARI P. , STENVALL HANNELE , UITTO VELI‐JUKKA
Published: October 2007

Abstract –

Pulpal tissue was incubated at 37°C for 10 min with various solutions used for root canal therapy. The dissolved material was assayed for hydroxyproline (HYP) and total phosphate, and the insoluble residue for HYP and dry weight. Sodium hypochlorite (NaOCl) at 5% and diluted to 2.5% showed the strongest solvent capacity measured as loss of HYP and weight from the tissue. Dilution to 0.5% significantly decreased the effectiveness of NaOCl. The absence of HYP from the NaOCl extracts suggested decomposition of this amino acid. The other solutions tested were far inferior in their ability to dissolve pulpal tissue. The demineralizing solutions tested were poor solubilizers of soft tissue; however, they caused a considerable increase in the amount of phosphate released.
Colchicines effects on rat incisor odontoblasts and dentinogenesis
Authors: DE OLIVEIRA NOGUEIRA TEREZINHA , STENE TORBJÖRN , KOPPANG HANNA STRÖMME
Published: October 2007

Abstract— Colchicine (CLC) in doses of 0.5 and 1.5 mg/kg was administered to 40 female Wistar rats in two equal grups. The animals were sacrificed after 5h, 24 h, 3 d and 7 d, and the effects of CLC on pulp, odontoblasts and dentin in the continuously growing incisors were studied. With the lowest ddose a few arrested mitoses were observed in the germinative part of the pulp afer 5 and 24 h. With the highest dosc an increasing number of mitoses weree observed in the geminative part of the pulp after 5 and 24 h. More incisally the odontoblasts were pale, swollen and granulated after 5 h, and necrotic and disintegarated after 24 h. After 3 and 7 d dentinal derangements, consisting of moderately and severely irregular dentin, osyteodenytin and a niche‐like defect in the labial dentin, were seen. Labially one or two incremental lines traversed the dentin form the apical to the incisal part of the incisors.
Method for studying the development, structure and microflora of denture plaque
Authors: BUDTZ‐JÖRGENSEN EJVIND , THEILADE ELSE , THEILADE JÖRGEN , ZANDER HELMUTH A.
Published: October 2007

Abstract – Pieces of sandblasted, self‐adhesive tape were stuck to the fitring surface of maxillary dentures in 17 edentulous subjects with climically normal palatal mucosa. After 1 week, during which the subjects abstained from denture hygience, the tape samples were removed for cultural and microscopical examinations. The microorganisms were suspended in RTF by ultrasonic treatment and total viable anaerobic counts and viable counts of yeasts per cm2 of tape were calculated after inoculation of serial dilutions on nonselective medium and Sabouraud agar. Total anaerobic viable counts ranged from 4×104 to 5×108. By repeated sampling the largest intra‐individual variation was 10‐fold, only. Yeast counts constituted less than 1% of the total viable counts in all but two of the subjects. Light and electron microscopy showed a bacterial plaque o predominantly cocci and rods.
Micrognathia, temporomandibular joint changes and dental occlusion in juvenile rheumatoid arthritis of adolescents and adults
Authors: LARHEIM T. A. , HAANÆS H. R.
Published: October 2007

Abstract – Clinical and radiographic examinations of the jaw skelecton of 20 patients aged 15–35 with juvenile rheumatoid arthritis (JRA) and a varying degree of micrognathia were made. Symmetrically underdeveloped mandible and unaffected maxilla were generally found by means of radiographic cephalomctry. Overjet (5–15mm) occurred in 10 patients, incisal protrusion in eight and distal molar relation in 16(bilaterally in 10). Temporomandibular joint (TMJ) symptoms, mainly pain and morning stiffness, were reported from case histories in 13 patients. Symptoms and signs at the examination were few, except crepitus found in 11 patients, and restricted mouth opening observed in al the patients. In four patients no symptoms had ever been noted. Severe radiographic changes were a characteristic feature in all the patients. Mandibular size (gn‐ar distance) was significantly smaller in patients with complete destruction of the madibular head than in those with partial destruction, indicating a causal relationship between mandibular underdevelopment and arthritis of the TMJ. Flat fossa, anteroposition of remnants of the mandibular head and reduced condylar movement an maximum opening of the mouth were found. Etiologic factors of micrognathia in JRA are discussed, as well as demand and need for treatment.
Spontaneous aggregation of Streptococcus mitis ATCC 903
Authors: ABAAS SALEEM , HOLME TORD
Published: October 2007

Abstract – Glucose or sucrose grown cells of Streptococcus mitis ATCC 903 bind spontaneously to thesurface of each other producing visible microbial aggregates upon incubation in 10 mM Phosphate, Citrate‐phosphate or tris‐maleate buffers. Aggregation was delayed and proceeded at a slower rate when bacteria grown in a culture medium with a low carbohydrate/nitrogen ration were used. Growth in this culture medium resulted in carbohydrate limitation. The aggregation was highly reproducible and was unaffected by pH in therange of 4.4–7.0 but was decreased at pH 8.0 and completely inhibited at pH 9.0. No inhibition of the reaction was observed when a series of simple and complex carbohydrates were added. The was no significant difference in the rate of aggregation at 20,30 and 37°C. Aggregation occurred at a demonstrable rate at 0°C. chloramphenicol did not inhibit aggregation. Since inhibition of aggregation was obtained by treatment of bacteria with trypsin or heat it appears that protein or glycoprotein components on the bacterial surface were involved in the reaction.
Method for determination of invertase acitivity in homogentes of human dental plaque
Authors: FIEHN NILS‐ERIK , MOE DENNIS
Published: October 2007

Abstract – Supragingival human dental plaque was ecllected from patients with evidence of caries. The plaque was frozen and stored at‐20°C. Pooled plaque was homogenized in acelate buffer pH 5.0 in an ice‐water bath. By incubating the homogenate at pH 5.0 with [U‐°C]‐sucrose the formation fo glucose and fructose was followed. Incubation in acetate buffer at pH 5.0 eliminated the glycosyltransferase activities adn teh glycolytic pathway. Normal Michaclis‐Menten kinetics were observed until about 40 mM sucrose. At highert concentration of sucrose, excess substrate inhibition occurred. Storage of the homogenate at −20° C resulted in decrease of the invertase activity with time.
Distribution of blood group antigens A, B and H in human fetal oral mucosal and odontogenic epithlium
Authors: VEDTOFTE P. , MATTHIESSEN M. E.
Published: October 2007

Abstract – The distribution of blood group antigens A, B andH was examinaed in human fetal oral mucosal and olontogenic epithelium. Tissue from 19 fetuses with crown‐rump lengths of 57 mm to 189 mm, corresponding to a fertilization age of 10–20 weeks, was included in the study. The distribution of blood group antigens was studied by immunofluorescence methods on tissue sections. Cell membrane bound blood group antigen A or B was demonstrated in the oral mucosal epithelium of 10 fetuses, whereas blood group antigen H was found in all fetuses. All the epithelial cell layers of the tooth germs were devoid of the blood group antigens A,B and H independent of the age of the fetus. The blood group antigens A, B and H were located on the cell membranes of the upper cell layers of the oral epithelium, whereas the basal cells showed no reaction even in the youngest fetuses. Following the differentiation of the epithelial cells, changes were seen in the distribution of the blood group antigens.
Corrosion of amalgams
Authors: BRUNE DAG
Published: October 2007

Abstract – The release of coppoer, mercury, silver, tin or zinc from conventional, dispersed phase and spherical high copper content amalgams immersed in artifucial saliva solutions for periods up to 30 d has been measured using nuclear tracer techniques. During initial corrosion, i.e. within a few hours, substaintial amounts of mercury were found to be present in particulate matter in the three type of amalgams. The release of particulate matter was pronounced for the dispersed phase type of amalgam. After about 30 d electrochemical corrosion was found to be the predominant process for release various corrosion products. Zinc was demonstrated to be the major corrosion product released to the artificial saliva solutions from conventional as well as dispresed phase amalgams. Due to low radioacivity levels silver and tin could not be quantitatively assayed. However, the upper limits of release of silver and tin in the artificial saliva solutions referring to exposure periods up to 30 d were estimated to 0.1 μg and 25 4mUg respectively. The chemical state of the various corrosion products has been evaluated. The deposition of CuCI2 3 Cu(OJ)2 on the surfaces of copper rich amalgams was observed according to X‐ray diffraction analysis.
Influence of combinations of oral bacteria on periapical tissues of monkeys
Authors: FABRICIUS LARS , DAHLÉN GUNNAR , HOLM STIG E. , MÖLLER AKE J. R.
Published: October 2007

Abstract – The present study deals with the ability of 11 bacterial strains, in various combinations, to induce periapical reactions. The indigenous oral bacteria were originally isolated from an experimental apical periodontitis in monkey. Eight of the strains were a complete collection isolated from one root canal. These strains were inoculated together, in equal proportions, into 12 root canals. In addition, 63 canals were inoculated with other combinations or separate strains. At the end of the experimental period it was found that in the mixed infections the Bacteroides oralis strain predominated in most root canals. In contrast, this Bacteroides strain was not reisolated in any of nine root canals when inoculated in a pure culmfe. Enterococci, however, survived as pure cultures in all canals. The mixed infections showed the greatest capacity ofindticing apical periodontitis, as revealed by radiography, and most pronounced was the “eight‐strain collection”. The facultatively anaerobic streptococci induced only weak periapical reactions.
Apical periodontitis induced by selected bacterial strains in root canals of immunized and nonimmunized monkeys
Authors: DAHLÉN GUNNAR , FABRIGIUS LARS , HEYDEN GUY , HOLM STIG E , MÖLLER AKE J. R.
Published: October 2007

Abstract – Experimental infections in root canals with Streptococcus faecalisss. liqiuefaciens (Strep‐MG4), Actinomyces bovis (Act‐MO6) and Bacteroides oraiis (Bact‐MC3) were studied in four immunized and five nonimmiLtnized monkeys. The immunization was performed using1 antigens of the homologous strains. The antibody level was checked by gel diffusion. In 56 root canals of the immunized animals and 60 root canals of the nonimmunized animals, viable cells of the three bacterial strains were enclosed in equal amounts in various combinations. After 6 months, samples from the root canals were subjected to qualitative and quantitative bacteriologic analyses and the apical area was radiographically and histologically examined. The analyses revealed no significant difference between the two groups of monkeys, although the viable cell recovery was slightly higher inmost of the root canals of nonimmunized monkeys. The cell proportion of the strains within the different bacterial combinations was equal in root canals of the two groups of animals. The radiograpihic and histologic examinations revealed no significant difference between the two groups of animals regarding the number of teeth with periapical lesions. The radiographic examination, however, showed a more distinct limitation of the process in the immunized than In the nonimmunized monkeys. Histologically the lesions were more encapsulated and had a sparser cell infiltration in immunized than in nonimmunized monkeys. In the latter, inflammatory cells had often infiltrated the bone. Mixed infections gave a more severe periapical reaction than single strain infections in both animal groups.
Studies of Candida serology in denture stomatitis patients
Authors: BERGENDAL TOM , HOLMBERG KENNETH
Published: October 2007

Abstract –The aim of the study was to determine the humoral antibody response to Candida by means of hemagglutinin and precipitin tests and to correlate these results to yeast colonization in the oral sites and feces and to the relapse tendency after treatment; and furthermore, to evaluate whether Candida serology can serve as a tool to predict a denture stomatitis risk group. The serologic tests were performed by means of passive hemagglutination (HA) and immunoelectroosmophoresis (counterimmunoelectrophoresis, CIE) tests in 51 denture stomatitis patients and compared with 25 individuals in the reference group. There were significantly more patients with increased hemagglutinin titers (pos. ≥1:160) to Candida albicans polysaccharide (mannan) antigen and/or precipitin to crude C. albicans cytoplasmic antigen in serum (P<0.01) than in the reference group. In the denture stomatitis group there was no correlation between the presence of hemagglutinating and precipitating Candida antibody in serum and the parameters yeast colonization of the oral sites/feces, yeast score on the denture base and palatal erythema score. After local oral antimycotic treatment there was no significant change in the serum Candida hemagglutinin titers and serum predpitins. Serologic tests might be useful as a guidance in a selected group of patients for continued prosthetic treatment and as a prognostic instrument.
Visible light‐cured composite resins: polymerization contraction, contraction pattern and hygroscopic expansion
Authors: HANSEN ERIK KEITH
Published: October 2007

Abstract – The wall‐to‐wall polymerization contraction and hygroscopic expansion of Durafill®, Heliosit®, Silux® and Visio‐Dispers® were examined in dendn cavities in extracted human teeth. The linear shrinkage varied from 0.24% to 0.63% and only two of the tested materials were able to close the marginal gap owing to water absorption. The gaps were nearly always broadest in the apical part of the fillings. Measurements of the marginal gaps were made at different levels between 100 and 1200 um below the free surface of the fillings and the wall‐to‐wall polymerization contraction was found to increase markedly from the level of 100 urn down to 800 um. The contraction pattern of the four light‐cured resins differed significantly from the one found in a chemically‐cured material.
Epidemiologic study of excessive oral melanin pigmentation with special reference to the influence of tobacco habits
Authors: AXEIX TONY , HEDIN C. ANDERS
Published: October 2007

Abstract – The prevalence of oral melanin pigmentation was studied in a population of 30 118 adult individuals in Sweden. Among these, 9.9% showed melanin pigmentation in the oral mucosa. The anterior labial gingiva in the mandible was the most frequently pigmented location. The presence of melanin pigmentation was positively correlated to tobacco smoking. Among tobacco smokers 21.5% were pigmented as compared to 3.0% among individuals not using tobacco. The smoking‐rdated oral pigmentation, smokers' melanosis, could thus be calculated at a prevalence of 18.5% among smokers and the total frequency of smokers' melanosis was calculated at 6.8%. The prevalence of pigmentation was found to increase promninendy during the first year of smoking but aiso to decrease to the level found among non‐tobacco users about 3 years after cessation of smoking. Snuff dipping did not significandy elevate the prevalence of oral melanin pigmentation.
Wholebody autoradiographic study after a single dose of204thallium in young rats
Authors: FAGERHOLM P. , FORESLIND B. , ISACSSON G. , THYRESSON N.
Published: October 2007

Abstract –The distribution of204TI uptake in young rats after intraperitoneal injection was studies. Densitometry showed that the highest accumulationof isotope was recorded in dentin and epithelial structures whereas the CNS has a comparatively low labeling. The uptake of different organs correlated well to the clinical symptoms recorded at acute thallium poisoning.
Microradiographic and histomorphometric indices of mandibles for diagnosis of osteopenia
Authors: VON WOWERN NINA
Published: October 2007

Abstract – Mandibular autopsy specimens of 100 Danish subjects without known systemic diseases were obtained. Microradiograms of 100‐μ‐thick undermineralized vertical bucconlingual ground cross‐sections and these sections, stained with basic fuchsin, were used. Microradiographic and histologic readings of bone turnover foci on Haversian canal and endosteal‐trabecular surfaces were compared and combined. The analyses show the following. 1) number/area Haversian canals with bone formation and resorption foci and total of Haversian canals are reproducible and representative measures of bone turnover, while estimation of % bone turnover surfaces on periosteal adn endosteal‐trabecular surfaces in biopsies of mandibles has no diagnostic value. 2) Percentage of bone mass and mean cortical width in standard locality indicate the level in group of mandibles. 3) The cortical variables of bone turnover are sex independentl number/area Haversian canals with resorption foci is age independentl number/area Haversian canals with bone formation foci, totalof Haversian canals and percentage of subendosteal (Haversian canals+marrow spaces) are increased with age.
Treatment of temporomandibular arthropathy
Authors: RASMUSSEN OLE COLLIN
Published: October 2007

Abstract – The favourable spontaneous course of TMA indicates a conservative approach to treatment. One‐half of the present 119 patients were either not treated by physiatric measures only. One‐third of the patients were treated by pivotation, whereby TMJ pain was relieved within an average of 2 months. Pivotation seemed to prolong the spontaneous course of TMA. Steriods were injected intraarticularly in one‐fifth of the patients, whereby TMJ pain was relieved within an average of 5 d. There were, however, symptoms other than pain that tended to persist after steroid injection. The various treatments did not result in any lasting differences in mandibular mobility. Pivotation and steroid injection seemed to result in a higher frequency of irregularity of the mandibular condyle as seen in transpharyngeal radiographs.
Corrosion of non –γ2– amalgams
Authors: DÉRAND TORE , JOHANSSON BEATRICE
Published: October 2007

Abstract – Abstract– Eight different dental amalgams were studied in an in vitro corrosion test. Cylindrical test specimens were stored in weak lactic acid solutions at different pH for 1 month. The concentrations of mercury and copper in the solutions were measured and corrosion depths estimated. The results indicated that more copper was released from non ‐ γ2 ‐ amalgams compared with conventional ones. The amounts of copper from these amalgams were not directly correlated to the concentration in the alloys. Mercury was released in much lower amounts than copper for all amalgams and seemed to originate from the γ1‐phase. A low pH promoted the corrosion.
Effect of pressure upon wall‐to‐wall polymerization contraction of a chemically‐cured resin
Authors: HANSEN ERIK KEITH
Published: October 2007

Abstract – The marginal gaps of 105 Silar® fillings were measured after application of a load between zero and 100 N on the matrix during the initial polymerization. The fillings were placed in non‐etched dentin cavities in extracted human teeth. The dentin surrounding the cavities was either roughened with carborundum paper No. 220 or polished with Alfa Micropolish® 1 μm before the cavities were filled. When load was applied to the matrix, no effect was found of the roughness surrounding the cavities, but without load the wall‐to‐wall contraction was significantly greater in cavities where the surrounding dentin surfaces had been polished with Alfa Micropolish. Apparently the effect of load was related to friction during the polymerization between filling surplus and the dentin surrounding the cavities and not to load per se.
Adsorption of glucosyltransferase to saliva coated hydroxyapatite Possible mechanism for sucrose dependent bacterial colonization of teeth
Authors: RÖLLA GUNNAR , CIARDI JOSEPH E. , SCHULTZ SANDRA A.
Published: October 2007

Abstract – Glucosyltransferase (GTF) adsorbed to hydroxyapatite and to saliva coated hydroxyapatite in vitro. Several proteins which are known to be present in the “pellicle” which forms on hydroxyapatite when this mineral is exposed to whole saliva were shown to stimulate or inhibit GTF. It is suggested that these proteins may interact with GTF and cause binding of the enzyme to saliva coated hydroxyapatite. A model is suggested where GTF adsorbed to tooth surfaces may induce binding of microorganisms to tooth surfaces.
Longitudinal study of salivary IgA in children from 1 to 4 years old with reference to dental caries
Authors: ALALUUSUA SATU
Published: October 2007

Abstract – The concentration of salivary IgA was measured and clinical examinations performed annually in 39 children over a period of 36 months. The age of the children ranged from 1 to 4 yr during the observation period. The geometric mean value of salivary IgA increased rapidly between the age of 1 and 2, from 0.021 g/l (log mean −1.68±0.33) to 0.052 g/l (log mean −1.28±0.24). After this age the mean level of salivary IgA remained fairly constant during the observation period. When the study population was divided into two groups: the caries‐free group and the caries‐susceptible group, it was found that in the caries‐free group the mean salivary IgA value increased rapidly during the second year of life, then more slowly after the age of 2. In the caries‐susceptible group the increase in the mean value between the ages of 1 and 2 was marked and at the age of 2 the values were significantly higher compared to those of the caries‐free group. The concentrations did not, however, remain high, but fell to lower level and at the age of 4 there was a marked overlap in the values of the groups.
Some aspects of the dynamics of Cu and Zn retained in plaque as related to their effect on plaque pH
Authors: AFSETH JOHN
Published: October 2007

Abstract – The effect of glucose on acid production in dental plaque was measured in vivo after oral rinses with CuSO4 (1.0 mM) or Zn (Ac)2 (20 mM) and compared with the retention of the metals. Plaque samples were analyzed for copper and zinc by neutron activation analysis. A rinse with the copper salt solution significantly depressed acid formation in plaque for a period of 6 h whereas a rinse with the zinc solution was effective for 2 h. Plaque concentrations of the metals increased from less than 75 p.p.m. to more than 1000 p.p.m. 2 h after a rinse with the metal salts. Twelve hours after a rinse the mean plaque concentrations were 190 p.p.m. Cu or 358 p.p.m. Zn respectively. Reducing the pH of the copper sulfate solution from 5.7 to 2.0 yielded lower Cu concentrations in plaque 2 h after a rinse, indicating lower initial retention. The results clearly demonstrate a high and long lasting retention of metal ions in dental plaque and their biological effect in this environment.
Effect of IRM on human dental pulp
Authors: MÖLLER BENGT , SCHRÖDER ULLA , GRANATH LARS
Published: October 2007

Abstract – IRM has been shown to be superior to conventional ZnOE cements. This study is a biotechnical investigation of IRM's effect on the dental pulp with respect to its sealing capacity. Enamel‐dentin test bodies with IRM fillings were used in the in vitro part, where insufficiencies in sealing were detected with compressed air. The in vivo part included 44 buccal cavities in intact premolars. In teeth in which the material effect of IRM was tested, the IRM fillings were sealed off from the saliva by acid etch and composite resin. The observation intervals were 1, 7 and 28 days. Histologic changes such as capillary dilatations and presence of inflammatory cells in the pulp adjacent to the dentinal tubules involved in the cavity preparation were registered. The in vitro test showed no leakage in five cases out of six. After extreme temperature cycling, the leakage was comparable with that of zinc‐containing amalgam of traditional alloy. The pulpal changes were mild and mainly ascribed to the material effect of IRM, since no evidence was found of leakage of biologic importance.
Weight loss of endodontic sealers, cements and pastes in water
Authors: ÖRSTAVIK DAG
Published: October 2007

Abstract – A solubility test based on weight loss in water, as proposed for standard testing programs (ADA & ISO), was adapted for assessing the solubility of 10 root canal sealers, cements and pastes. The weight loss of the set materials during 24 hr in distilled water at 37°C ranged from –0.84 (AH26) to 22.71 (Kloroperka N‐Ö) weight percent. The results were reproducible, and the test was considered suitable for routine testing of weight loss in water of endodontic materials. However, the test may not provide information which is directly related to the clinical behavior of the materials.
Corrosion of amalgams with special regard to zinc
Authors: JOHANSSON BEATRICE , DÉRAND TORE
Published: October 2007

Abstract – Five dental amalgams were studied in an in vitro corrosion test. Cylindrical test specimens were stored in weak lactic acid solutions at different pH for 1 month. The solutions were analyzed for zinc, the specimens were inspected and examined in SEM. The results showed that zinc was dissolved rather quickly from the amalgams and the amount was highest for the conventional one. Some amalgams had a low tendency for corrosion products to adhere to the surfaces. The presence of zinc did not seem to reduce their corrosion resistance.
Working time of dental amalgams
Authors: JÖRGENSEN KNUD D.
Published: October 2007

Abstract – The purpose of the present work was to study the setting of amalgams made from several different commercial alloys by recording the rate of initial mercury consumption, and then to compare the findings with those from other methods of defining the early setting process. The results show that the rate of initial mercury consumption is well correlated with clinicians’ classification of the rate of setting of amalgams, but not correlated with mechanical tests like early compressive strength and guillotine setting time used till now in estimating the working time of amalgams. Based on these findings an appropriate method of determining the mercury :alloy proportion and working time of dental amalgams is suggested.
Porosity in microfill restorative composites cured by visible light
Authors: JÖRGENSEN KNUD DREYER , HISAMITSU HISASHI
Published: October 2007

Abstract – Previous studies indicate that porosity in dental microfill composite restoratives reduces the clinical qualities of this group of materials. Porosity may decrease the optical quality of restorations and is probably a strong factor in reducing wear resistance of Class 1 fillings. In view of possibly eliminating this disturbing factor it was the purpose of the present work to study the effect of variables in the clinical technique on porosity. Initially it was found that filling by spatula as well as paste‐paste mixing of non‐porous microfill materials caused high porosity, and that the visible light curing microfill brands studied were pore‐free as delivered by manufacturers. Consequently only this type of material was studied in detail and only when applied by syringing technique. Poor adaptation of composite to tube inside and to cavity walls as well as too small diameter of the tube tip were found to be factors greatly adding to porosity. In cylindrical cavities, 3 mm in diameter and 2 mm deep, porosity could be consistently reduced to zero by wetting the inside of the tube as well as the cavity walls by a drop of visible light curing monomer and by use of tube with a tip opening of 1.0 mm. Similar positive results were obtained for simulated Class 1 fillings. No adverse effects of this technique were found.
Keratin pattern in human oral buccal and hard palate mucosa
Authors: CLAUSEN HENRIK , VEDTOFTE POUL , MOE DENNIS , DABELSTEEN ERIK
Published: October 2007

Abstract – As a preliminary study the keratin proteins of human oral stratified epithelia from buccal mucosa and hard palate were investigated using SDS‐PAGE technique. The keratinized hard palate consistently showed six polypeptides varying in molecular weight from 47 to 67 k daltons, whereas the nonkeratinized buccal epithelium lacked the larger polypeptides and showed three polypeptides with molecular weight from 50 to 56 k daltons. The individual variations in the SDS‐gel pattern from eight clinically normal individuals were restricted to minor quantitative differences.
Preparation of midsagittal semithin Epon sections of the entire secretory ameloblast population in the maxillary rat incisor
Authors: WINTHER‐NIELSEN HENRIK
Published: October 2007

Abstract – To study cytological changes in the migrating cell layer of the ameloblasts in the rat incisor with semithin Epon sections the ideal section plane would consequently be along the midsagittal plane of the incisor. However, the small dimensions and the complex three‐dimensional structure of the apical part of the odontogenic organ covered by alveolar bone make it difficult to orientate and position sections in the midsagittal plane. Serial sectioning of the apical half of the maxillary incisor in the horizontal and sagittal planes clarified the relation of the midsagittal plane of the odontogenic organ to the alveolar bone, and the changes of the sectional profile of the odontogenic organ as a function of its position on the transverse axis of the incisor. From this information a method was designed whereby the two axes of the midagittal plane were marked directly on the block surface before sectioning, and the position of sections in the midsagittal zone of the ameloblasts standardized.
Ultrastructural visualization of the adherence of Streptococcus mutans and Streptococcus salivarius to hydroxyapatite
Authors: MEURMAN JUKKA H. , TUOMPO HELENA , LOUNATMAA KARI
Published: October 2007

Abstract – S. mutans and S. salivarius adherence to saliva‐coated and saliva‐uncoated hydroxyapatite was studied by transmission and high resolution scanning electron microscopy. No difference was observed between the saliva‐coated and saliva‐uncoated study series of adherence. The attachment of individual bacteria to apatite crystals was found to be mediated by cell wall projections. These electron‐dense structures were characteristically well formed in S. mutans, and even in S. salivarius the projections appeared to link the bacteria to the apatite. The site of attachment in the bacterial cell wall was always at the division area. We suggest that the possible metabolic activity at the cell wall division site, therefore, also works in the adherence process.
Effect of pellicle on galvanic corrosion of amalgam
Authors: HOLLAND ROY I.
Published: October 2007

Abstract – Galvanic corrosion of amalgam, induced by contact with a type IV dental casting gold alloy, was determined under simulated oral conditions in an electrochemical cell. The effect of a pellicle layer formed by 1 h exposure to saliva in the oral cavity was determined. Pellicle on the amalgam had no effect on the maximum corrosion rate or the 2 h corrosion charge, whereas pellicle on the gold alloy substantially reduced both these parameters of the conventional low‐copper amalgam; the corrosion of the high‐copper amalgam was less and was not influenced by pellicle formation.
Slide‐scoring method for estimation of Streptococcus mutans levels in saliva
Authors: ALALUUSUA SATU , SAVOLAINEN JOUKO , TUOMPO HELENA , GRÖNROOS LISA
Published: October 2007

Abstract – A method was developed to facilitate the estimation of S. mutans levels in saliva. Paraffin‐stimulated saliva was poured on a special slide coated with mitis‐salivarius‐sucrose agar. Two discs containing bacitracin (5 μg) were placed on the inoculated slide and the growth density of S. mutans around the bacitracin discs was scored after incubation in candle jars at 37°C for 48h. The obtained score values correlated well with the numbers of CFU of S. mutans per 1 ml of saliva estimated by a conventional method using mitis‐salivarius‐bacitracin agar. The experimental method was further tested by incubating the slides in an atmosphere created by CO2 generating tables that were placed into the cover tubes of the slides. These score values were similar to those after conventional incubation. The method is suggested for epidemiologic studies and in selecting persons at high risk for caries and in controlling the effectiveness of prophylactic measures of these patients.
Marginal porosity of light activated composites in relation to use of intermediate low‐viscous resins
Authors: HANSEN ERIK KEITH
Published: October 2007

Abstract – The marginal porosity of four light activated restoratives (Command, Durafill, Prismafill and Silux) was investigated in extracted human teeth It was found that the use of a lowviscous resin prior to application of the restorative materials significantly reduced the marginal porosity in both acid etched enamel cavities and EDTA‐cleaned dentin cavities.
Initial acidity of dental cements
Authors: BRUNE DAG , EVJE DAG MAGNAR
Published: October 2007

Abstract – The acidity in aqueous solutions following release of acid components from glass ionomer, silicate, zinc phosphate and zinc polycarboxylate cements has been registered by pH measurements. One brand of each type was studied. Initial setting was accomplished at two different temperatures; 23°C and in the interval from 23°C to about 60°C. In the latter case external heat was transferred to the samples by infrared radiation for a period of 2 min. The highest acidity was associated with the silicate specimen, while the lowest acidity was recorded for the zinc polycarboxylate specimen. Exposure to infrared radiation resulted in a reduced acidity for all types of cements. The effect of infrared exposure was most pronounced for the silicate specimens, resulting in a reduction of acid release by a factor of about 10 compared to the nontreated samples. The resistance to acid release was found to be improved by a factor of about 5 for the glass ionomer and about 3 for the zinc phosphate cement treated in a similar way. Clinically, it seems possible considerably to reduce the risk of pulpal injuries associated with the insertion of silicate restorations by using a moderate infrared radiation treatment. Furthermore, the susceptibility of glass ionomer cements to a high initial erosion should be reduced by the use of such a technique. After exposure of the glass ionomer and silicate specimens to infrared radiation at the temperature interval applied, the samples had a more glossy, tooth‐like appearance compared to the nonexposed samples, improving the aesthetic properties.
Distortion of wax crowns
Authors: JÖRGENSEN KNUD DREYER , ONO TAKASHI
Published: October 2007

Abstract – Distortion of wax crown patterns is unavoidable. This distortion is sufficient to reduce the fit of the final restoration to a degree that is clinically unacceptable. The wax distortion may be ignored only by use of die‐investing technique. However, an ideal investment for this technique is at present not available.
Scanning and transmission electron microscopy of the phagocytosis of Treponema denticola and Escherichia coli by human neutrophils in vitro
Authors: OLSEN INGAR , LINGAAS EGIL , HURLEN BJÖRN , MIDTVEDT TORE
Published: October 2007

Abstract – In the present in vitro study, scanning and transmission electron microscopy demonstrated that human neutrophils are able to phagocytize Treponema denticola cells. Two major modes of particle engulfment were detected, both of which seemed unaffected by opsonization or atmosphere (aerobic or anaerobic). The occasional finding of rather intact treponemes as long as 2 h after onset of the phagocytosis experiment, suggested that digestion could be a relatively slow process. Expulsion of digested material from the phagolysosomes to the extracellular space seemed to occur via channel‐like structures in the neutrophil cytoplasm.
Peptidergic nerves in human tooth pulp
Authors: GRÖNBLAD MATS , LIESI PÄIVI , MUNCK ANNE MARIE
Published: October 2007

Abstract – Substance P‐like and enkephalin‐like immunoreactive nerve fibers were observed in the human tooth pulp. Immunoreactivity for substance P could be demonstrated in thin, beaded nerve fibers and glomerular‐type nerve structures both in the center and in more peripheral parts of the tooth pulp. Substance P‐like nerve fibers predominated in the center of the pulp substance, while a thicker type of enkephalin‐like nerve fibers were more commonly seen at the periphery of the pulp. Controls exhibited no immunoreactivity for either neuropeptide. It is tentatively suggested that a dual innervation by substance P‐like fibers and enkephalin‐like nerve fibers may be involved in the mediation of toothache in man.
Enzyme histochemical characterization of mononuclear cells in human dental periapical chronic inflammatory lesions
Authors: JOHANNESSEN ANNE C. , NILSEN RUNE , SKAUG NILS
Published: October 2007

Abstract – Cell infiltrates in sections of paraffin‐embedded tissue of 36 human periapical inflammatory lesions (15 granulomas and 21 cysts) were examined by staining for acid α‐naphthyl acetate esterase (ANAE). Thirty‐four of the lesions showed ANAE reactive T lymphocytes, plasma cells and cells of the monocyte/macrophage cell line. Large granular lymphocytes (NK cells) could not be identified with certainty among the ANAE positive cells. Two specimens were free of ANAE reactive cells. Differential cell counts on sections from 15 lesions (7 granulomas and 8 cysts) showed that T lymphocytes were the predominating ANAE reactive cells (23%), followed by plasma cells (15%) and monocytes/macrophages (11%). 51% of the inflammatory cells were ANAE negative. There was no marked difference between the granulomas and the cysts. Inhibition with NaF (10–100 mM) gave a gradual reduction in number of ANAE positive cells, some macrophages being the only cells resistant to 100 mM NaF. The results suggest that both humoral and cellular immune reactions are likely to occur in periapical inflammatory lesions.
Scanning electron microscopic study of orthodontically induced injuries to the periodontal membrane
Authors: LINDSKOG SVEN , LILJA EVA
Published: October 2007

Abstract – Scanning electron microscopy was used to study vascular and cellular changes in the periodontal membrane (PDM) in rats after orthodontic treatment ranging from 3 h to 9 days. The orthodontic forces ranged between 200 mN and 400 mN. Within the first hours of treatment extravasated erythrocytes, eichinocytes and platelets in various stages of degeneration were found in the pressure zones. The connective tissue of the pressure zones developed an amorphous appearance lacking discernible fibers and blood vessels following treatment for 24 h. These areas are known as hyaline zones, an area of local aseptic necrosis. Three days after the application of an orthodontic force macrophage‐like cells were abundant close to the hyaline zone. They adhered to the hyaline zone with filopods radiating from pseudopods. Large osteoclast‐like cells with several projections towards the bone surface were found around the hyaline zone and in the marrow spaces close to the pressure zones. The results indicated that the tissue reactions leading to remodeling of the PDM in the pressure zones are closely related to vascular injuries and subsequent formation of coagulated blood. Furthermore, macrophages seem to be the cells which play the most important role during degradation of the hyaline zone.