bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Responsiveness of Mouse Submandibular Gland to Androgen and Thyroid Hormone
Authors: Takuma Taishin , Hosoda Satoko , Tanemura Tatsuya , Kumegawa Masayoshi
Published: November 2010

The effects of thyroxine and 5α-dihydrotestosterone on the activities of various marker enzymes in the submandibular glands of immature mice were studied. The responsiveness to thyroid hormone appeared at latest by day five after birth, which was ten d earlier than the appearance of androgen responsiveness. The activity of trypsin-like esteroprotease, however, was not increased by these hormones until day 15 after birth.
Maximum Incisal Biting Force in Denture Wearers as Influenced by Adequacy of Denture-bearing Tissues and the Use of an Adhesive
Authors: Tarbet Willard J. , Silverman Gerald , Schmidt Nicholas F.
Published: November 2010

Maximum incisal biting force was measured in 21 subjects by gnathodynamometry. Biting force was directly related to the quality of the denture support tissues. Biting force was increased and denture dislodgements reduced, especially in those with unsatisfactory support tissues, by the use of a test adhesive.
Molar Size Sequence in American Blacks
Authors: Malhotra S.K. , Richardson E.R.
Published: November 2010

The purpose of this study is to present the data on molar size sequence (MSS) in American Blacks. The results are compared with other studies on American Whites. It is evident from the findings that a reasonably high percentage of M2 > M 1 (where second molars are larger mesiodistally than first molars) exists in both the groups. This suggests that the M2 > M1 molar sequence should not be considered as a primitive characteristic, since a high percentage of this sequence is seen in the modern population. The percentage of incidences of M2 > M1 in the maxillary arch seems to be significantly higher in American Whites, in both the sexes and as a total group, than in American Blacks. In the case of the mandibular arch, the percentage is significantly higher in American Blacks.
The Tensile and Shear Strength of a Base Metal Weld Joint Used in Dentistry
Authors: MacEntee M.I. , Hawbolt E.B. , Zahel J.I.
Published: November 2010

Samples of a base metal alloy were cast and welded together using a conventional welding procedure. The joints were loaded and placed either in a corrosive environment or in air for varying time periods. The tensile and shear strength of the joints was unaffected by the corrosive environment, and the joints, despite some internal defects, appeared suitable for clinical use.
Alteration of Lidocaine- or Procaine-induced Convulsions by Manipulation of Brain Amines
Authors: Ciarlone Alfred E.
Published: November 2010

Lidocaine and procaine seizure thresholds were studied. The i.p. median convulsant dose (CD50) of lidocaine and procaine with saline pre-treatment was 95 and 240 mg/kg, respectively. Dopamine depletion by pre-treatment with d1-α-methyl-p-tyrosine plus dihydroxyphenylserine resulted in a significant drop of CD50 to 69 and 175 mg/kg for lidocaine and procaine, respectively. Serotonin depletion by pre-treatment with p-chlorophenylalanine resulted in a significant drop of CD50 to 68 mg/kg for lidocaine, but no significant change for procaine.
The Effects of Desensitizing Agents on the Hydraulic Conductance of Human Dentin in vitro
Authors: Greenhill Joël D. , Pashley David H.
Published: November 2010

The hydrodynamic theory of dentin sensitivity states that a stimulus applied at the orifice of exposed dentinal tubules causes movement of tubular fluid which stimulates nerve receptors. The fluid should obey principles of fluid movement through capillary tubes. Any decrease in the functional radius of the dentinal tubules should greatly reduce the rate of fluid flow, thus reducing dentinal sensitivity.

The purpose of this study was to evaluate the ability of agents that have been used previously for clinical dentin desensitization to reduce the rate of fluid flow through dentin in vitro.

Dentin discs prepared from extracted human third molars were treated with 50% citric acid to remove debris from tubular orifices. After placing the discs in a split chamber device, the rate at which buffer solution could filter across the dentin under 240 cm of water pressure was measured. The occlusal side of the disc was then treated with an agent thought to desensitize dentin to determine if it reduced fluid flow rate. Discs that had more than a 50% reduction in flow rate were examined by scanning electron microscopy to determine if those agents that decreased fluid flow also partially occluded tubular orifices. This in vitro model provided a useful quantitative method for screening a host of preparations that have been used in the past to decrease dentin sensitivity.
Biosynthesis of Prostaglandin E2 and F2a in Gingiva of Patients with Chronic Periodontitis
Authors: Elattar Tawfik M.A. , Lin Hsien S.
Published: November 2010

The biosynthesis of radioactive prostaglandin E2 (PGE2) and F2α from (] .14C) arachidonic acid has been demonstrated in the microsomal fraction of gingiva of patients with chronic periodontitis in vitro. 14C corresponding to unmetabolized arachidonic acid in three separate incubations was 83, 66, and 83%, and that corresponding to both PGE2 and PGF2α was 8, 22, and 9% of the total radioactivity recovered after chromatography. The ratios of PGE2 to PGF 2α were found to be 6:1, 6:1, and 3:1, respectively.
Comparison of in vitro and in vivo Dog Dentin Permeability
Authors: Pashley David H. , Kehl Thomas , Pashley Edna , Palmer Patricia
Published: November 2010

A method is described which permits the quantitation of the rate of permeation of 1311 through dog dentin, both in vivo and in vitro. The results demonstrate the rapidity of the systemic appearance of substances placed on intact dentin. Comparison of the rate of permeation of 131I made in vivo and in vitro, on the same teeth, indicates the rates are very similar.
Clinical Science
Authors: Gibbs M. , Retief D.H. , Bradley E.L. , Taylor R.E. , Walker A.R.
Published: November 2010

Acidulated phosphate fluoride (APF), Duraphat or Fluor Protector, was applied to the molar teeth of rats fed a cariogenic diet. The first maxillary molar teeth were subjected to a microbiopsy procedure for fluoride analysis and the mandibular molars scored for caries. All three topical fluoride agents produced a significant increase in the fluoride content of the outermost 5.0 μm of enamel. Only APF produced a significant reduction in caries incidence at all sites.
Isolated Parotid Acinar Cells from Patients With Cystic Fibrosis. Functional Characterization
Authors: Mangos J.A.
Published: November 2010

Studies of the homeostasis and secretory function of isolated parotid acinar cells from patients with cystic fibrosis were conducted. It was demonstrated that the transmembrane fluxes of Na and the muscarinic cholinergic receptor stimulus-secretion coupling were depressed, while the stimulus-secretion coupling of the beta-adrenergic receptor was hyper-reactive.
Binding of Eugenol and O-ethoxybenzoic Acid to Bovine Serum Albumin
Authors: Fujisawa Sechiro , Masuhara Echi
Published: November 2010

The binding constants (log K) of eugenol, o-ethoxybenzoic acid, and their analogues, plus other organic compounds widely used in dentistry with bovine serum albumin, were examined with respect to the partition coefficients of these compounds in octanol-water (log P). Linear relationships between log K and log P values were obtained with high relative coefficients. Eugenol and o-ethoxybenzoic acid showed a relatively large log K value.
Clinical Science
Authors: Rugg-Gunn A.J. , Edgar W.M. , Jenkins G.N.
Published: November 2010

Plaque pH in six adult subjects was monitored while they consumed a meal containing three foods. The marked fall in plaque pH caused by drinking sugared coffee was considerably reduced by eating the two non-sugary foods (egg and crisp-bread) before, during, or after the sugared coffee. This favorable action was negated by a pause between the sugary and non-sugary courses.Received for publication March 20, 1980 Accepted for publication July 30, 1980
Naturally-occurring IgA Antibodies to Glycerol-teichoic Acid in Human Saliva. Correlation with Caries Activity
Authors: Bolton Ronald W.
Published: November 2010

Human subjects were examined for caries activity and for naturally-occurring salivary IgA of glycerol-teichoic acid (TA) specificity by an enzyme-linked immunosorbent assay. Subjects free of active caries produced higher levels of anti-TA in their saliva than persons with one or more active carious lesions.
Determination of the AuCu Superlattice Formation Region in Gold-Copper-Silver Ternary System
Authors: Uzuka Tsutomu , Kanzawa Yasuo , Yasuda Katsuhiro
Published: November 2010

The composition and temperature range of the AuCu-type superlattice formation in the Au-Cu-Ag ternary system was determined by X-ray powder diffraction. Four distinguishable phase transformations were detected, i.e., 1) α (disordered FCC phase) → AuCu I, 2) α → AuCu II, 3) α → α1 (Cu-rich FCC phase) + α 2 (Ag-rich FCC phase), and 4) α → AuCu3. The stable temperature range of the AuCu I-type superlattice was restricted to a lower temperature range by adding silver to stoichiometric and off-stoichiometric Au-Cu alloys. Depending on the increase in silver content, the co-existing region of the AuCu II-type superlattice and the silver-rich α2 phase extended to the lower temperature and over a wide composition range.
Influence of Contact Stress, Sliding Velocity, and Surface Roughness on the Sliding Wear of a Composite Restorative
Authors: Bailey William F. , Rice Stephen L. , Albert Ronald J. , Temin Samuel C.
Published: November 2010

The influence of several experimental parameters on the sliding-wear behavior of a composite restorative has been examined. The results demonstrate that: 1) Changes in surface finish and sliding velocity have little effect on the moderate wear-rate observed at nominal levels of stress, and 2) increased contact stress can profoundly alter wear mechanisms and produce marked surface failure at levels well within the range associated with human mastication.
Behavior of Odontoblasts and Basal Lamina of Trypsin or EDTA-isolated Mouse Dental Papillae in Short-term Culture
Authors: Osman Mohammad , Ruch Jean-Victor
Published: November 2010

Embryonic mouse first mandibular molars (day 18), containing the first overtly differentiated odontoblasts, were treated with EDTA or trypsin, to obtain isolated dental papillae. Trypsin dissociation was accompanied by disappearance of the basal lamina. EDTA-treatment removed the basal lamina from the basal surface of the epithelium, but left it associated with the dental papillae. EDTA- or trypsin-isolated dental papillae were grown for three to 24 h at the top of a plasma clot. Trypsin-isolated dental papillae rapidly lost their typical morphology, and the post-mitotic odontoblasts never became functional. EDTA-isolated dental papillae remained covered by the basal lamina for 15 to 18 h. During this period, the typical morphology was maintained, and post-mitotic odontoblasts secreted predentin. Pre-odontoblasts and odontoblasts went through the basal lamina and migrated at the outer surface of the basal lamina (i.e., at the side facing away from the enamel organ).
Organic-bound Chromium in Enamel, Dentin, and Bone Studied by Electron Spin Resonance
Authors: Doi Yutaka , Aoba Takaaki , Okazaki Masayuki , Takahashi Junzo , Moriwaki Yutaka
Published: November 2010

A g=1.980 signal due to trivalent chromium observed in electron spin resonance (ESR) spectra of bovine enamel, dentin, and bone, which were heated at temperatures above 900°C before observation, indicates strongly that chromium is associated with organic constituents of the calcified tissues. The concentrations of chromium in the tissues have been estimated with the ESR technique.
The Influence of Mineralizing Solutions on the Bonding of Composite Restorations to Dentin. Cyanoacrylate Pre-treatment
Authors: Causton B.E. , Johnson N.W.
Published: November 2010

Cyanoacrylate cement is used as an adhesion promoter for both quartz-filled and resin-filled composite restoratives, with the cyanoaciylate being protected from hydrolysis by various mineral layers grown on and in the dentin surface.
Measurement of Regional Bone Blood Flow in the Rabbit Mandible Using the Hydrogen Washout Technique
Authors: Indresano A.T. , Lundell M.I.
Published: November 2010

This investigation involved quantitating blood flow in rabbit mandible using the hydrogen washout technique. The animal was ventilated with a H2/O2 gas mixture. Hydrogen concentration was monitored by surgically implanted platinum electrodes. The Fick principle was used to interpret the H2 washouts. The following mean flows were obtained: Cortical bone, 4.49 ml/100g/min; condylar bone, 8.22 ml/100g/min; and alveolar bone, 18.33 ml/100g/min. This technique proved repeatable and compared well with other studies.
Histological Considerations of Direct Pulp Capping Agents
Authors: Heys D.R. , Cox C.F. , Heys R.J. , Avery J.K.
Published: November 2010

The results from this study showed a variety of pulpal responses to various calcium hydroxide materials when placed directly on the dental pulp. Two of the materials proved to be more successful at stimulating reparative dentin bridging and healing of the underlying pulp tissue. The remainder of the pulp capping agents were ineffective at healing the pulp and forming a reparative dentin bridge. When teeth were capped with these other agents, the pulp showed necrosis and chronic inflammation.
Salivary Calculi: Ultrastructural Morphology and Bacterial Etiology
Authors: Lustmann J. , Shteyer A.
Published: November 2010

Ultrastructural morphology of 16 salivary calculi was studied by means of transmission and scanning electron microscopy. The external surface was mostly globular or coarse, and on high magnifications the features could be divided into four main groups: a) amorphic calcified deposits covering extensive areas, b) other areas covered with crystals in a variety of arrangements, c) heavy accumulations of calcified rod-like and filamentous-like microorganisms, and d) platelet crystals in juxtaposition to calcified microorganisms in several areas. In most calculi the split area was found to be laminated. It is suggested that microorganisms have an important role in the formation and growth of salivary calculi.
Effects of a Single Application of Sodium Fluoride Gel on Dental Plaque Acidogenesis
Authors: Brown L.R. , White J.O. , Horton I.M. , Perkins D.H. , Streckfuss J.L. , Dreizen S.
Published: November 2010

The quantities of lactate and acetate produced by human dental plaque were compared before and after five-minute exposures to 1% sodium fluoride gel. A single topical application of the gel increased plaque fluoride by about 700 ppm, 79% of which was lost after six h. Gel use significantly reduced plaque L(+)-lactate production in vitro, and the production of L(+)- and D(-)-lactate and acetate in situ.
The Effect of Saliva on Plaque pH in vivo
Authors: Abelson D.C. , Mandel I.D.
Published: November 2010

The impact of saliva on plaque pH in vivo, following exposure to a sucrose substrate, was measured in ten caries-resistant (CR) and ten caries-susceptible (CS) subjects under varying conditions of salivary access. When the plaque was denied access to saliva, the pH minima reached by the CR and CS groups were comparable. As the access to saliva was increased, the observed pH minima increased to a significantly greater degree in the CR subjects than in the CS subjects. This demonstrates the major role that saliva plays in modifying plaque pH, especially in caries-resistant people.
The Inorganic Phase in Dentinogenesis imperfecta
Authors: Kerebel B. , Daculsi G. , Menanteau J. , Kerebel L.M.
Published: November 2010

High resolution TEM, X-ray diffraction analysis, infrared absorption spectroscopy, thermogravimetry, and chemical and electron microprobe analyses showed that in dentinogenesis imperfecta the mineral phase is a carbonated apatite with crystallites of normal size, but less numerous than in normal dentin. Losses of Ca, P, and Mg, and a higher Ca/P ratio and water content were recorded.
A Thermal Shock Test for Porcelain-Metal Systems
Authors: Anusavice K.J. , Ringle R.D. , Morse P.K. , Fairhurst C.W. , King G.E.
Published: November 2010

A thermal shock test was employed to evaluate the crazing resistance of 55 porcelain-metal systems. The effect of the porcelain brand used was the most significant determinant of porcelain crazing. The effects of the alloys and alloy-porcelain combinations, although also significant, were second order effects.
A Comparison of the Inflammatory Response Produced by Commercial Eugenol and Purified Eugenol
Authors: Webb J.G. , Bussell N.E.
Published: November 2010

Eugenol is one of the major therapeutic agents in dentistry. The inflammatory responses to purified and commercial eugenol are compared, and the inflammatory responses to zinc oxide/eugenol prepared with either purified or commercial eugenol are also compared. The results indicate that eugenol is inflammatory, but the impurities present in commercial eugenol increase the inflammatory response to eugenol and zinc oxide/ eugenol.
Stain Removal from a Silicone Maxillofacial Elastomer
Authors: Yu R. , Koran A. , Raptis C.N. , Craig R.G.
Published: November 2010

In this study, environmental stains were removed from maxillofacial elastomers by solvent extraction. Silastic 44210, an RTV silicone with proven color and physical property stability, was stained with lipstick, disclosing solution, and methylene blue. These stains were then removed by solvent extraction with each of four chemically dissimilar solvents, namely: toluene, benzene, 1,1,1-trichloroethane, and n-hexane. An additional series of samples was prepared with 11 maxillofacial pigments, not for staining, but for evaluation of pigment stability. Results obtained from spectrophotometric measurements before and after solvent extraction demonstrated the effectiveness of solvent extraction in removing stains, while there was little or no change in the color of the pigments or the base elastomer.
Composite Resins with a Condensable Inorganic Phase
Authors: Ehrnford L.
Published: November 2010

Open porous particles consisting of a sintered three-dimensional glass network were impregnated with BIS-GMA-based liquid resins. Formulations containing highly viscous resins allowed the particles to be condensed by a packing technique similar to that used for dental amalgam.
The Mineralization of Enamel Surfaces. A Constant Composition Kinetics Study
Authors: Amjad Z. , Koutsoukos P.G. , Nancollas G.H.
Published: November 2010

The in vitro remineralization of acid-etched enamel surfaces offers an attractive model for simulating carious lesion recalcification and the repair of teeth in the oral environment. In the present work the influence of the extent of etching with hydrochloric and phosphoric acids has been examined. The kinetics of growth of hydroxyapatite as an exclusive phase on the pretreated enamel surfaces has been studied by means of a constant solution composition procedure. This method enables studies to be made at low constant supersaturations so that the stoichiometry of the precipitating phase may be defined. The very small rates of mineralization with HAP were determined with a precision hitherto unattainable. In addition, the influence of fluoride ion in enhancing the remineralization of damaged enamel has been investigated.
Comparative Effect of SnF2, NaF, and SnCl2 on the Growth of Streptococcus mutans
Authors: Mayhew R.R. , Brown L.R.
Published: November 2010

The inhibitory effects of NaF, SnF2, and SnCl2 were compared in vitro on the growth of Streptococcus mutans NCTC #10449. Sodium fluoride arrested growth at 300 and 600 ppm F (while SnF2 suppressed the rate of growth at 75 ppm F), showed some bactericidal activity at 150 and 300 ppm F, and was totally bactericidal at 600 ppm F. The greater inhibition by SnF2 suggests an additive effect of Sn2+. As a measure of a fluoride-free Sn2+ solution, SnCl2 was inappropriate since most of the tin present, at a neutral pH, was Sn4+. The influence of pH was particularly noteworthy with SnF2 at 600 ppm F, where a total bactericidal effect was observed within four h at pH 5.9, while viable cells were still recoverable from four to 40 h with SnF 2 at pH 7.2.
The Effect of Topical Fluoride Agents on Fluoride Uptake and Surface Morphology
Authors: Wefel J.S. , Harless J.D.
Published: November 2010

Four topical fluoride agents were evaluated in vitro for their ability to form permanently bound fluoride. APF, NH4F, and Na2SnF6 formed soluble reaction products, while TiF4 did not. Surface coatings were present on those samples that showed higher levels of fluoride after washing.
Degradation of Glass Filler in Experimental Composites
Authors: Söderholm K.-J.
Published: November 2010

A degradation of untreated fillers in composites stored in distilled water was indicated by an increased sodium and hydroxy ion concentration in storage water, and by examination of the fillers with SEM. Silane treatment of the fillers retarded the leaching process, while cycling stresses accelerated it.
Fluoride Uptake from in situ Brushing with a SnF2 and a NaF Dentifrice
Authors: Mobley M.J.
Published: November 2010

Fluoride uptake into decalcified human enamel was determined from in situ brushing with a 0.40% SnF2-calcium pyrophosphate abrasive dentifrice, a 0.243% NaF-silica abrasive dentifrice, and a non-fluoride-silica abrasive placebo dentifrice. Dentifrice treatments were compared using a randomized block test design with 11 panelists, wearing specially fabricated partial dentures that were able to hold two 3-mm-diameter enamel discs in proximal positions. The enamel discs were analyzed for fluoride after two wk of regular use of the test dentifrices. The mean fluoride contents after use of the test dentifrices were 16.0, 8.4, and 4.6 μg/cm2 for the 0.243% NaF, the 0.40% SnF2, and the placebo dentifrice, respectively. The differences in the means were statistically significant. These uptake results correlate well with the reported clinical efficacies of these dentifrices.
Materials Science
Authors: Vankerckhoven H. , Lambrechts P. , Van Beylen M. , Vanherle G.
Published: November 2010

The monomer systems of conventional composites and smooth-surface microfilled composites were studied by means of nuclear magnetic resonance spectroscopy. The monomer composition varied from brand to brand. Obviously, this will result in different physical properties and clinical behavior.

Transmission electron microscopy revealed the presence of a free submicron fraction in the monomer system of some restorative resins.
Correlated Light and Scanning Electron Microscopy of Artificial Carious Lesions
Authors: Hubbard M.J.
Published: November 2010

Artificial carious lesions formed in human enamel were studied by light microscopy and scanning electron microscopy. Scanning electron microscopy of enamel surfaces, prepared by fracturing, revealed features which could be correlated with the zonal pattern observed with light microscopy. A control study of non-carious enamel revealed features previously attributed to caries.
Identification of Significant Variables for Pulpal Reactions to Dental Materials
Authors: Qvist V. , Stoltze K.
Published: November 2010

The variation in the long-term pulpal reactions to 60 experimental fillings in intact human premolars was analyzed by the General Linear Model procedure. Results showed that variations in the experimental conditions related to individual, tooth, and cavity preparations significantly influenced the degree of the reactions. Considering these factors in the design of experiments and in the interpretation of results, the discriminatory power of the tests will increase.
Creep and Corrosion of Amalgam
Authors: Mahler D.B. , Adey J.D. , Marek M.
Published: November 2010

Creep and corrosion were determined for an amalgam that demonstrates both the absence or presence of γ2 depending on final Hg content. The results showed that corrosion was directly related to the amount of γ2 present, while creep was either low or high depending on the absence or presence of γ2.
Resistance to Extrinsic Stains by Hydrophobic Composite Resin Systems
Authors: Douglas W.H. , Craig R.G.
Published: November 2010

Measurement of color parameters demonstrated that hydrophobic composites had less staining capacity and greater ease of stain removal when compared with conventional composite materials. Accelerated aging of samples is important in staining tests.
Calcification and Crystallization in Bovine Enamel
Authors: Sakae T. , Hirai G.
Published: November 2010

The degree of crystallinity of the inorganic components in bovine enamel during maturation was calculated and was compared with the degree of calcification. The process of calcification was quantified using monochromatic X-ray microradiography, and the extent of crystallization was analyzed using an X-ray microdiffraction method.

The results showed two notable phenomena: (1) that calcification continued for a short time after the eruption of the tooth, and (2) that the crystallization of the inorganic components was delayed in relation to the process of calcification before eruption, but caught up and progressed rapidly after eruption.
Increased Collagen Synthesis by Gingival Fibroblasts Derived from a Papillon-Lefevre Patient
Authors: Cheung H.S. , Landow R.K. , Bauer M.
Published: November 2010

Both skin and gingival fibroblasts in the Papillon-Lefévre patient synthesized Type I and Type III collagen in a ratio very similar to fibroblasts of control cells. The only abnormality appeared to be elevated levels of collagen and protein synthesis by gingival cells derived from the Papillon-Lefévre patient.
The Prevalence of Juvenile Periodontitis ("Periodontosis") in a Dental School Patient Population
Authors: Barnett M.L. , Baker R.L. , Yancey J.M.
Published: November 2010

In order to obtain additional information about the prevalence of juvenile periodontitis, a retrospective, cross-sectional study was performed utilizing the dentulous patient pool of an urban dental school. For a one-year period, 2.4% of patients between the ages of 13 and 30 were found to have juvenile periodontitis.
A Microbiological Analysis of Human Early Carious and Non-carious Fissures
Authors: Meiers J.C. , Wirthlin M.R. , Shklair I.L.
Published: November 2010

The fissure sampling technique consisted of removing the fissure using a bur in a high-speed handpiece with water spray and then suctioning the fissural contents and the water spray into a sterile sampling container. Sixty-eight teeth were sampled. Total bacterial counts, total streptococcal counts, and counts of Streptococcus mutans, Streptococcus sanguis, Streptococcus faecalis, Actinomyces viscosus, and lactobacilli were performed on the fissural samples. There was a four-fold increase in the total number of microorganisms recovered from carious (N=48) compared to non-carious (N=20) fissures. S. mutans was the only microorganism common to all carious fissures.
Plasmid Content of Some Oral Microorganisms Isolated from Subgingival Plaque
Authors: Vandenbergh P.A. , Syed S.A. , Gonzalez C.F. , Loesche W.J. , Olsen R.H.
Published: November 2010

Eighty-five strains of bacterial species selected from the predominant cultivable dental plaque flora of patients with different periodontal pathologies were examined for their plasmid content. Microorganisms studied included: Actinomyces viscosus, A. odontolyticus, Bacteroides asaccharolyticus (B. gingivalis), B. melaninogenicus subspecies intermedius, and subspecies melaninogenicus, Capnocytophaga ochracea (B. ochraceus), and Fusobacterium nucleatum. Three B. melaninogenicus isolates showed plasmids of approximately 2.7-2.9 Mdalton (mega-dalton) molecular size. Restriction, enzyme digests of the plasmids demonstrated dissimilar patterns when electrophoresed on agarose gels. In other microorganisms, including the Actinomyces species, plasmids were not observed.
Extracellular Iodophilic Polysaccharide Synthesized by Neisseria in Human Dental Plaque
Authors: Ruby J.D. , Shirey R.E. , Gerencser V.F. , Stelzig D.A.
Published: November 2010

Dental plaque collected from the labial aspect of the anterior dentition of children harbored Neisseria that synthesized an extracellular iodophilic polysaccharide (EIP) from sucrose. Gas chromatograms of fully-acetylated EIP derivatives indicated that glucose (97%) and galactose (3%) were the only monosaccharide constituents present. The characterization of the partially-methylated alditol acetate (PMAA) derivatives of EIP indicated that it was primarily a linear 1,4 glucan (75.5%), with some 1,6 glucan (8.4%). The relative linearity of EIP (96.6%) as compared to that of amylose and glycogen was confirmed by spectrophotometric absorption studies.
Effect of Gramicidin D on the Acidogenic Properties of Oral Streptococci and Human Dental Plaque
Authors: Vadeboncoeur C. , Proulx M. , Trahan L.
Published: November 2010

The effect of gramicidin D, gramicidin S, and carbonylcyanide p-trifluoromethoxyphenyl hydrazone on the glycolysis of various oral streptococci was investigated. Gramicidin D was the most effective and inhibited the glycolysis of all the streptococci studied in the presence of the most common sugars found in man's diet (sucrose, lactose, glucose, and fructose). A concentration of 2.5 X 10-6 M gramicidin D was sufficient to decrease significantly the rate of glycolysis of human dental plaque in the presence of sucrose. The use of this ionophore as a caries preventive agent is discussed.
Phagocytic and Killing Activity of Human Blood, Gingival Crevicular, and Salivary Polymorphonuclear Leukocytes for Oral Streptococci
Authors: Scully C.
Published: November 2010

The phagocytic and killing capacities of human blood, gingival crevicular, and salivary polymorphonuclear leukocytes for oral streptococci have been examined. Crevicudar and salivary leukocytes were active in phagocytosis and killing of oral streptococci, but were impaired in these respects compared with blood leukocytes.
Fluoride Release from a Silicophosphate Cement with Added Fluoride
Authors: Derkson G.D. , Poon P.J. , Richardson A.S.
Published: November 2010

The fluoride release from a silicophosphate cement with added fluoride was compared to that from glass ionomer and silicophosphate cements. The fluoride-enriched cement was found to release four times more fluoride than did the glass ionomer cement and five to 15 times more fluoride than did the silicophosphate cement.
Precipitations in a Dental Ag-Pd-Cu-Au Alloy
Authors: Herø H. , Jørgensen R. , Sørbrøden E. , Suoninen E.
Published: November 2010

The structure of a dental Ag-Pd-Cu-Au alloy has been studied after centrifugal casting and various heat treatments. By transmission electron microscopy, a high density of small fct particles, assumed to be PdCu, was observed, but, in addition, finely-spaced rods of ~ 0.05 μm (500 Å) diameter with an fcc structure precipitated on the {100} planes of the matrix were found. On the basis of their structure and the pertaining lattice parameter, these rods are assumed to be Cu-rich. They could also be observed by scanning electron microscopy, but not at annealing temperatures lower than 425° C.
Effect of Increasing the Bulk Content of the Diet on the Rat Parotid Gland and Saliva
Authors: Johnson D.A. , Sreebny L.M.
Published: November 2010

Parotid gland enlargement was induced in rats by incorporating non-nutritive bulk into the stock diet. The magnitude of gland enlargement was directly correlated to the percentage of bulk in the diet. The protein concentration of parotid saliva was increased, but the composition of secretory proteins was not noticeably affected.
Formation of 12L-Hydroxyeicosatetraenoic Acid (12-HETE) by Gingival Tissue
Authors: Sidhagen B. , Hamberg M. , Fredholm B.B.
Published: November 2010

Extracts of inflamed human gingival tissue converted exogenous [14C] -arachidonic acid mainly to a non-prostaglandin metabolite. This metabolite was identified as 12-hydroxyeicosatetraenoic acid (12-HETE) by gas-liquid chromatography-mass-spectometry. Endogenous arachidonic acid was also converted to 12-HETE. Significant formation of PGF2α , PGD2, PGI2, Thromboxane B, or 12-HHT could not be detected, but, in occasional experiments, significant conversion of arachidonic acid to PGE2 was found.
Drug-Nitrite Interactions in Human Saliva: Effects of Food Constituents on Carcinogenic N-Nitrosamine Formation
Authors: Rao G.S. , Osborn J.C. , Adatia M.R.
Published: November 2010

A simple and rapid high-pressure liquid chromatographic assay for monitoring N-nitrosodimethylarnine (NDMA) in human saliva was developed. The method was used to study in vitro the effects of common food constituents on NDMA formation in saliva from the interaction of salivary nitrite with aminopyrine and oxytetracycline. Natural phenolic compounds, caffeic acid, and tannic acid, and synthetic additives, erythorbic acid, sorbic acid, propyl gallate, and butylated hydroxytoluene - all inhibited NDMA formation (20-80%). With ascorbic acid, up to 90% inhibition of NDMA synthesis in saliva was observed. In contrast, chlorogenic acid (a phenolic component of coffee) acted as a catalyst (up to 48% increase) of the nitrosamine formation under identical experimental conditions.
Aging Reactions in a Low Gold, White Dental Alloy
Authors: Hisatsune K. , Ohta M. , Shiraishi T. , Yamane M.
Published: November 2010

Aging behavior of a low gold, white dental alloy was investigated by electrical resistivity measurements, X-ray diffraction, and electron microscopy. It was characterized by both grain interior and grain boundary reactions. The coexistence of AuCu-I and CuPd in dental alloys was first confirmed.
Empirical Verification of Confidence Intervals Computed from Dental Data
Authors: Cohen M.E. , Cecil J.C.
Published: November 2010

Sampling experiments were conducted on five distributions of dental epidemiological data which varied in degree of positive skew. The tendency of nominal confidence intervals to be underestimated and asymmetric in the two tails increased with skew and decreased with increasing sample size. The findings conform to theoretical expectations and demonstrate the importance of the normality assumption regarding sampling distributions. A rule is presented which identifies a sample size so that the 95% confidence probability statement would be incorrect no more than 6% of the time.
Ultrastructural Quantitation of Connective Tissue Changes in Phenytoin-induced Gingival Overgrowth in the Ferret
Authors: Hall B.K. , Squier C.A.
Published: November 2010

Ultrastructural quantitation has been used to determine both the effect of phenytoin (PHT) on gingival connective tissue components and the cellular basis for these changes. The results suggest that the amount of ground substance increases, and this may be due to decreased degradation within fibroblasts.
In vitro Hydrolysis of Monofluorophosphate by Dental Plaque Microorganisms
Authors: Jackson L.R.
Published: November 2010

The ability of suspensions of natural supragingival plaque, artificial plaque, and Streptococcus mutans KIR to hydrolyze sodium monofluorophosphate, Na2PO 3F (MFP), was investigated using a fluoride-selective electrode. S. mutans KIR cells produced minimal hydrolysis. Enzymes in plaque suspensions rapidly hydrolyzed MFP to liberate fluoride ion, a possible mechanism for the cariostatic action of monofluorophosphate dentifrices.
The Use of the Beagle Dog as a Dental Stain Model
Authors: Schemehorn B.R. , McDonald J.L. , Stookey G.K.
Published: November 2010

Two studies were conducted to assess stain accumulation in beagle dogs following four wk of treatments with water or chlorhexidine. Clinical stain assessments were made by two examiners using different grading procedures. Both scoring methods demonstrated increased stain associated with chlorhexidine usage, and the results for both examiners appeared to be reproducible from one study to the other.
Clinical Science
Authors: Nagumo M. , Sakurada S. , Enomoto S.
Published: November 2010

Experiments were performed to examine the function of neutrophil membrane receptors in oral bacterial infections. For this purpose, Fc and C3b receptors on human peripheral blood neutrophils and exudate neutrophils obtained from subcutaneous abscesses were studied by using the rosette-forming method.
Stain Removal from a Pigmented Silicone Maxillofacial Elastomer
Authors: Yu R. , Koran A. , Craig R.G. , Raptis C.N.
Published: November 2010

The removal of environmental stains from a pigmented maxillofacial elastomer was carried out by solvent extraction under network swelling. Silastic 44210 was pigmented with 11 maxillofacial pigments prior to staining. Samples were stained with lipstick, methylene blue, and disclosing solution. These stains were then removed by solvent extraction with 1,1,1-trichloroethane. Color parameter measurements both before and after staining and after solvent extraction demonstrated the effectiveness of removing these stains by solvent extraction while causing little or no change in the color of the pigmented samples.
Visco-elastic Properties of Some Room-temperature Polymerizing Resins
Authors: Clarke R.L. , Braden M.
Published: November 2010

Visco-elastic properties of a number of room-temperature polymerizing resins have been determined using a torsional pendulum apparatus. The storage and dissipative components of the complex shear modulus were determined in the temperature range 20- 180°C, together with the mechanical loss
Clenched Jaw Jerks in Children
Authors: Josell S.D. , Yaeger J.A. , Gay T.
Published: November 2010

Masseter muscle silent periods were assessed in 24 children divided into three groups according to their stage of dental development (primary, mixed, and permanent). Surface electrode EMG data, timing code, and microphone input were recorded on magnetic tape. A visual record was obtained by playing the tape into an optical oscillograph; measurements were maae from the photosensitive paper. The results indicate the latency and silent period durations of clenched jaw jerks were similar among the three groups. For the subjects in this study, the mean latency and silent period durations of the masseter muscle during clenched jaw jerks were 14.9 ms (milli-seconds) and 27.0 ms.
Age Dependency of Stimulated Salivary Flow Rate, pH, and Lactobacillus and Yeast Concentrations
Authors: Parvinen T. , Larmas M.
Published: November 2010

No significant influence of age on the stimulated salivary flow rate or pH was observed in a cross-sectional study of unmedicated adults. The females had a lower output than did the males in every age group. A tendency toward higher salivary counts of lactobacilli and yeasts with aging was observed.
Effects of Continuous Patient Information in the Dental Environment
Authors: Thrash W.J. , Marr J.N. , Box T.G.
Published: November 2010

The effects of varying knowledge of an information system and belief in the effects of this information on discomfort during dental treatment were measured. The information system consisted of patient-operated buttons connected to a series of lights which provided continuous information to the dentist concerning the relative comfort of the patient. Actual information, false information, and knowledge of the information system were combined to form experimental groups.

The results showed that those individuals with the ability to provide information to the dentist reported less discomfort than those without this ability during a scaling procedure. During the polishing procedure, the belief of the effect of information resulted in a decrease of reported discomfort.
Effects of Phase Transformations of Silicas and Calcium Sulfates on the Compressive Strength of Gypsum-bonded Investments at High Temperatures
Authors: Ohno H. , Nakano S. , Miyakawa O. , Watanabe K. , Shiokawa N.
Published: November 2010

The effects of transformations of silicas and calcium sulfates on high temperature compressive strength were investigated in commercial and experimental investment materials containing fused quartz as silica. The strength is only slightly affected by the α → β transformation of cristobalite and not by the quartz α → β transformation. The state of the calcium sulfates is the main factor influencing variations in the strength at a particular temperature.
The Remineralization of Fluoride-treated Bovine Enamel Surfaces
Authors: Amjad Z. , Koutsoukos P.G. , Nancollas G.H.
Published: November 2010

Various etching methods are examined with respect to their ability to induce the surface nucleation and growth of fluorapatite from solutions of low, sustained supersaturation with respect to hydroxyapatite and fluorapatite. The constant composition kinetics method enables the rates of remineralization to be precisely determined, and the possibility of the direct growth of fluorapatite on calcium fluoride crystals in calcium phosphate solutions of low supersaturation has also been examined.
Mandibular Bone Turnover During Calcium Deficiency in the Rat
Authors: Murray E.J. , Messer H.H. , Alamoudi N.
Published: November 2010

Bone resorption and deposition during calcium deficiency were compared in the mandible, femur, and vertebrae. While resorption did not differ markedly among the three sites, mineral deposition was lowest in the mandible, leading to a greater net loss of mineral than from femur or vertebrae.
Effect of Phosphate Deficiency on Pulp Alkaline Phosphatase and Ca2+-, Mg2 + -ATPase Activity in Rats
Authors: Messer H.H. , Guo M.K. , Goebel N.K.
Published: November 2010

Phosphate deficiency imposed on weanling rats for two wk resulted in a 40% increase in alkaline phosphatase activity of incisor pulp, without a significant change in Ca2+-, Mg2+ -ATPase activity. The results are consistent with a separate identity for the two enzymes, but their physiological roles remain obscure.
Comparison of Methods for Monitoring Changes in the pH of Human Dental Plaque
Authors: Schachtele C.F. , Jensen M.E.
Published: November 2010

Changes in human dental plaque pH can be used to obtain estimates of the acidogenic potential of ingested foods. The presence of acid in plaque is influenced by a large number of host, microbial, and substrate factors. Several useful methods have been developed for monitoring changes in plaque pH. Plaque sampling involves repeated removal of small samples of plaque from a number of teeth at intervals after food ingestion, dispersion of the sample, and in vitro measurement of pH. Touch electrode methods utilize glass or antimony microelectrodes, which are placed onto plaque in situ where direct readings can be obtained. Telemetry methods involve placement of glass microelectrodes or ion-sensitive field effect transistors within the dentition. Plaque is allowed to accumulate, and pH changes can subsequently be transmitted with radio or wire. Each of the methods has clear advantages and limitations. The methods have been simultaneously compared in human volunteers using solutions of fermentable carbohydrate. Inter-method differences in response were observed depending upon the site of measurement. Data obtained from caries-prone surfaces via telemetry showed lower pH minima and retarded returns to resting pH levels. The technology is available for controlled comparative plaque pH studies, with the method of choice depending upon the goals of the investigation. It is essential that the results be compared to data obtained with other models designed to evaluate the cariogenic potential of foods.
Duration of Response and Stimulus Sequence in the Interpretation of Plaque pH Data
Authors: Edgar W.M.
Published: November 2010

Evaluation of cariogenicity from evidence provided by plaque pH data may be assisted if the duration as well as the extent of the pH fall is examined. Consumption of foods in sequence may alter the pH response to individual items.
Metabolism of Androgens by Human Periodontal Ligament
Authors: Vittek J. , Rappaport S.C. , Gordon G.G. , Hagedoorn J. , Southren A.L.
Published: November 2010

The metabolism of androgens (testosterone and androstenedione) has been studied in healthy and diseased human periodontal ligaments. An increased activity of 17β-oxidoreductase and 17-keto-5α-A-ring reductase and decreased activity of 17β-hydroxy-5α-A-ring reductase, 3αβ-oxidoreductase and 5β-A-ring reductase have been found in diseased periodontal ligament.
A Comparison of Whole Mouth Resting and Stimulated Salivary Measurement Procedures
Authors: Navazesh M. , Christensen C.M.
Published: November 2010

Methods for collection and stimulation of whole mouth saliva were compared. Resting salivary flow values were roughly equivalent for draining, spitting, suction, and swab collection techniques, but the swab technique was less reliable. Gustatory and masticatory stimuli induced significantly higher salivary flow compared to resting levels, but the between- and within-subject variances were also higher. Stimulation produced a fairly constant addition of saliva whether individual resting flow levels were low or high.
Lipid Composition of Submandibular Saliva from Normal and Cystic Fibrosis Individuals
Authors: Slomiany B.L. , Aono M. , Murty V.L.N. , Slomiany A. , Levine M.J. , Tabak L.A.
Published: November 2010

The submandibular saliva of patients with cystic fibrosis was found to contain about 66% more lipids/100 ml of saliva than that of normal individuals and exhibited elevated levels of neutral lipids, phospholipids, and glycolipids. No significant differences were noted in the proportions of individual neutral lipid and phospholipid components present in both types of samples. The glycolipids of normal saliva consisted entirely of glyceroglucolipids, whereas those of cystic fibrosis saliva, in addition to glyceroglucolipids, also contained small amounts of glycosphingolipids. These quantitative and qualitative differences may affect the physicochemical properties of the secretion.
Influence of Chemicals on Wear of Dental Composites
Authors: Wu W. , McKinney J.E.
Published: November 2010

The wear resistance of a commercial dental restorative composite exposed to different chemicals was measured with a pin-disc apparatus. The initial wear rate increased dramatically once the composite had been immersed in chemicals known to soften the cross-linked matrix material, which is a copolymer derived from BIS-GMA and diluent monomer. The increase of wear rate in a chemically softened composite was found to persist over a depth beyond 160 μm for specimens immersed over two wk prior to wear testing.
Evaluation of Salivary IgA Antibodies to Cariogenic Microorganisms in Children. Correlation with Dental Caries Activity
Authors: Bolton R.W. , Hlava G.L.
Published: November 2010

Children were examined for caries activity, and their salivary IgA was evaluated for reactivity to antigens of cariogenic bacteria by an enzyme-linked immunosorbent assay (ELISA). IgA levels to Streptococcus mutans were higher in children with no detectable caries. Analysis of IgA specific for Lactobacillus casei, teichoic acid, and glucan revealed no protective role for these specificities in children.
Dental Caries and Periodontal Disease in an Indochinese Refugee Population
Authors: Diangelis A.J. , Rojas A.J.
Published: November 2010

Caries and periodontal disease data from 205 Indochinese refugee 12-to-19-year-olds were obtained and were analyzed on the basis of sex, ethnic group, and access to dental care. A mean DMF score of 6.2 and a mean P.I. score of 1.2 were recorded for the total sample. Greater caries experience was noted in females and in the Vietnamese teenagers.
Effect of Hydrophilic Diluents on the Properties of Cured Composites
Authors: Dermann K. , Rupp N.W. , Brauer G.M.
Published: November 2010

Hydrophilic diluents in composite formulations slightly increase water sorption of cured resin. This increased water uptake does not result in a significant improvement in the marginal adaptation, although other properties of the resulting composites are very satisfactory.