bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical and Materials Sciences
Authors: Okabe T. , Mitchell R. , Butts M.B. , Bosley J.R. , Fairhurst C.W.
Published: November 2010

The reaction zone surrounding the Ag-Cu eutectic dispersant in Dispersalloy amalgam was found by selected area reflection electron diffraction to consist of Cu6Sn5 and Ag2Hg3. These electron diffraction data confirm electron probe studies by Mahler and his associates.
A Study of "Broken Appointment" Patients in a Children's Hospital Dental Clinic
Authors: Fazio Robert Charles , Boffa Joseph
Published: November 2010

An investigation of possible variables dictating "No Show" batient behavior relative to scheduled dental appointments was undertaken. Source of payment for services and race demonstrated statistical associations with "No Show" behavior. Race was confounded with the former variable. Two third-party payment groups demonstrated different fail-cancel behavior when compared.
Improving the Fracture Resistance of Dental Ceramic
Authors: Dunn B. , Levy M.N. , Reisbick M.H.
Published: November 2010

A time-temperature sequence for optimally strengthening dental ceramic by ion exchange was investigated. Stress relaxation occurs at higher temperatures and/or longer times. Improved strengths are obtained in a reasonable period of time that could be used for clinical application.
The Effect of Diphenylhydantoin on Fibroblasts In Vitro
Authors: Keith David A. , Paz Mercedes A. , Gallop Paul M.
Published: November 2010

Human fibroblasts have been cultured in the presence of Diphenylhydantoin. No consistent stimulation of cell growth was observed. The drug at a concentration of 0.02 mM, in the presence of ascorbic acid, decreased collagen prolyl hydroxylation in "old" W1-38 cultures but a concentration of 0.1 mM was required to decrease prolyl hydroxylation in "young" cultures.
Microstructure of Dental Amalgams Containing High and Low Copper Contents
Authors: Malhotra Manohar L. , Asgar Kamal
Published: November 2010

Microstructure of commercial dental alloys and their amalgams were studied primarily by x-ray diffraction, optical metallography, scanning electron microscopy, and x-ray energy dispersive spectroscopy. X-ray diffraction revealed more phases than normally reported in these materials. Presence of new phases was discussed and their formation mechanism understood. Some phases having interacting 2θ° values with others were properly identified. Both new and conventional dental alloys and their amalgams, namely Tytin, Sybraloy, Dispersalloy, Kerr Spheraloy, Caulk Spherical, Shofu Spherical, and Caulk 20th Century Microcut were used to complete the investigation.
Volunteering in Dental Peer Review: Differences Between Volunteers and Practitioners at Large
Authors: Milgrom P. , Ratener P. , Weinstein P. , Read W. , Morrison K.
Published: November 2010

This report characterizes dzfferences among early and late volunteers, and non-volunteers for personal characteristics and situational determinants of volunteering in an experimental dental peer review study. Differences were found jor volunteers/nonvolunteers for some items representing subject interest, expectation of a favorable evaluation, sociability, and achievement motivation.
The Rheological Characteristics of Elastomeric Impression Materials
Authors: Combe E.C. , Moser J.B.
Published: November 2010

An indirect extrusion viscometer has been used to assess the shear rate dependence of viscosity of a range of pastes supplied for elastomeric impression materials. A suggested specification for these pastes has been proposed.
The Effect of Some Divalent Cations on Extracellular Polysaccharide Synthesis in Streptococcus salivarius
Authors: Boyd Robert F.
Published: November 2010

The amount of extracellular insoluble polysaccharide produced by Streptococcus salivarius can be effected by some divalent cations. Calcium at concentrations of 1 × 10-3 and 10-4 M caused a reduction in polysaccharide synthesis. Magnesium at 1 × 10-3 M inhibited extracellular polysaccharide production but at 1 X 10-4 M had little effect. Manganese was without effect on polysaccharide synthesis. Zinc at 1 X 10-3 and 1 X 10-4 M caused a substantial increase in extracellular polysaccharide synthesis.
Experimental Formation of "Corn Cob" In Vitro
Authors: Takazoe Ichiro , Matsukubo Takashi , Katow Toshiko
Published: November 2010

Organisms isolated from corn cob were examined for aggregation with Bacterionema matruchotii. Such aggregations, interpreted as corn cob formation, in vitro, occurred with five isolates identified as Streptococcus sanguis. A cell-surface component of Streptococcus sanguis or a phospholipid-related substance of Bacterione ma matruchotii appeared to be involved.
Color of Dental Restorative Resins
Authors: Dennison Joseph B. , Powers John M. , Koran Andrew
Published: November 2010

The color of 7 composite resins, an unfilled restorative resin, and 3 glaze coatings was determined by reflection spectrophotometry and visually with Munsell color tabs. Statistically significant correlations existed between comparable parameters of the spectrophotometric and Munsell data. There were observable color variations among the 11 resins studied, but only 3 materials were within the range for natural tooth color.
Physical Properties of Zinc Phosphate Cement Prepared on a Frozen Slab
Authors: Tuenge Rodney , Siegel Ivens A. , Izutsu Kenneth T.
Published: November 2010

The physical properties of a zinc phosphate cement prepared on a room temperature slab were compared to those of the cement prepared on a frozen slab. Solubility, compressive strength, and setting time of cements prepared on both types of slabs were within the limits set by A.D.A. Specification No. 8.
Immunotherapy of Chemically-Induced Tumors in the Hamster Cheek Pouch with Dinitrochlorobenzene
Authors: Marshack Martin , Toto Patrick , Kerman Ronald
Published: November 2010

Immune stimulation with an agent such as dinitrochlorobenzene (DNCB) may delay chemcal carcinogenesis. Dimethylbenzanthracene (DMBA) was used to chemically induce tumors in the hamster buccal pouch. Hamsters were studied for the effect of DNCB sensitization in the buccal pouch prior to or after DMBA tumor induction. At appropriate time intervals the hamsters were sacrificed and each cheek pouch was examined histologically for the development of DMBA-induced tumors and for the presence of lymphoid cells infiltrating the tumor site. The results show that DNCB immunotherapy or immunoprophylaxis prior to or following DMBA tumor induction can alter the type of tumor produced and stimulate an infiltration of lymphoid cells into the tumor area probably invoking immune defense mechanisms.
Determination of Arbitrary Tooth Displacements
Authors: Pryputniewicz R.J. , Burstone C.J. , Bowley W.W.
Published: November 2010

The noninvasive, modern technique based on the method of double-exposure hologram interferometry was used to measure arbitrary displacements of teeth in the three dimensional space. The experimental studies were carried out on an idealized model of the maxillary central incisor. The results show that the experimental data, based on component loading, are inadequate to accurately predict tooth displacement from an arbitrary force acting in the three dimensional space.
Effect of Cooling Techniques on Temperature Control and Cutting Rate for High-Speed Dental Drills
Authors: Lloyd B.A. , Rich J.A. , Brown W.S.
Published: November 2010

This paper describes a series of tests conducted to determine the effectiveness of various cooling techniques used while preparing teeth for restoration. Comparisons are presented for four cooling techniques: air stream, air-water spray, water stream from a separate hand-held syringe, and water applied through a hollow bur. The comparisons were made in two ways, temperature control and influence on cutting rate. It was demonstrated that wet cooling techniques provided better temperature control than cooling with air and also improved the rate of material removal.
A Study of High Copper Amalgams. II. Amalgamation on a Hg-Plated High Copper Alloy Containing 30 Wt% Cu
Authors: Okabe T. , Mitchell R. , Wright A.H. , Fairhurst C.W.
Published: November 2010

The amalgamation reaction of a low silver, high copper alloy powder has been investigated by plating tablets of compacted powder with Hg. Both y, Ag-Hg and η Cu-Sn crystals form on the tablets. In spite of large differences in composition, these tablets amalgamated similarly to the T tablets studied and reported in Part I.
The Effect of Metal/Fluoride Complexes on Fluoride Uptake and Caries-like Lesion Formation in Enamel
Authors: Clarkson Brian H.
Published: November 2010

Pretreatment of enamel with TiCl3 and ZrOCL2·8H2O solutions prior to APF application was shown to increase fluoride uptake and reduce caries-like lesion formation to a greater extent than APF alone. The increase in fluoride uptake by enamel was not solely due to the low pH of the pretreatment solutions.
Etches for the Microstructure of Dental Amalgams
Authors: Abbott J.R. , Makinson O.F.
Published: November 2010

An iodized sodium hydroxide solution. is suitable as an etch for conventional amalgams. In diluted form and followed by sodium thiosulfate solution, this may be used on dispersed phase, ternary and quaternary alloy amalgams for clearer results than with the cyanide method. Alternative etches are given for ternary-quaternary materials.
Fermentation Characteristics of Strains of Streptococcus mutans
Authors: Lyon T.C.
Published: November 2010

Realization of the important role of Streptococcus mutans in the initiation of dental caries has resulted in extensive studies of all its biologic characteristics. The ultimate goal is to control or eliminate it from the oral cavity. One means of accomplishing this is to reduce or eliminate its carbohydrate source. This study reports those carbohydrates which Streptococcus mutans cannot metabolize.
Effect of Fluoride Topical Solutions on Enamel Demineralization by Lactate Buffers and Streptococcus mutans in vitro
Authors: Zahradnik R.T. , Propas D. , Moreno E.C.
Published: November 2010

Applications of APF and NaF solutions to extracted human teeth reduced the extent of enamel subsurface demineralization induced by colonization of S. mutans but were ineffective against demineralization by acid lactate buffers. It is concluded that the CaF2 formed on the tooth surface during the treatment is responsible for the protection observed.
Use of the Munsell System to Compute Color Differences in Composite Resins
Authors: Moser J.B. , Wozniak W.T. , Muller T.P. , Moore B.K.
Published: November 2010

Color changes resulting from immersion of four composite resins in hot distilled water, coffee and tea were measured by a tristimulus colorimeter. Changes are shown as CIE ΔE values and converted to Munsell ΔH, ΔV and ΔC values.
Cell Production in the Normal and Lathyrogenic Rat Periodontal Ligament (PDL)
Authors: Michaeli Yael , Zajicek Professor Gershom , Ginio Itzhak
Published: November 2010

Thirty male albino rats weighing 200 g. each were separated into two groups. 15 rats received 0.2% 3-amino propionitrile fumarate (BAPN) in drinking water. 15 rats served as controls. Within three weeks eruption rate diminished by 50%. On the 22nd experimental day each rat received one dose of 1 μCi/g. body weight tritiated thymidine (1.9 Ci/mM). 5 rats of each group were then killed after 1 hour, 1 week and 2 weeks. The PDL cell migration rate was evaluated autoradiographically. It diminishes proportionally with the eruption rate. In the BAPN treated animals, the mean total periodontal ligament (PDL) cell count is 55.5% higher than that of the control.
Comparative Enamel Histology of Primate Teeth
Authors: Gantt D.G.
Published: November 2010

The use of nonhuman primates as experimental models has markedly increased during the past decade. However, very little is known about primate dental tissues, especially enamel. Comparative studies of the enamel from 25 primate species reveal a wide variation in (1) the thickness of enamel, (2) microstructure and ultra-structure, and (3) the species' capacity to respond to systemic stress. These data provide a baseline of information presently not available to the dental researcher.
Chemical Determinants of Enamel Hypoplasia in Children with Disorders of Calcium and Phosphate Homeostasis
Authors: Nikiforuk G. , Fraser D.
Published: November 2010

Studies of children with disorders of calcium and phosphate homeostasis indicate that hypocalcaemia, but not hypophosphataemia, is a significant and specific factor in the etiology of enamel hypoplasia. Only those teeth were affected that had developed during the hypocalcaemic episodes.
Cellular Regulation of the Metabolism of Androgens in Rat Oral Mucosa. III. Activation of Δ4-3-ketosteroid-5α-A Ring Reductase Enzyme System by 5,5-Diphenylhydantoin
Authors: Vittek Jozef , Gordon Gary G. , Rappaport Sydney C. , Southren A. Louis
Published: November 2010

Systemic pretreatment of rats with diphenylhydantoin (DPH) or its addition into an in vitro assay increases 5α-reduction of testosterone by the oral mucosa. Enzyme kinetic studies showed that DPH binds to the enzyme and probably activates it by an allosteric mechanism.
Effects of Adhesion Promoters on Resin-enamel Retention
Authors: Jedrychowski Joseph R. , Caputo Angelo A. , Foliart Roberta
Published: November 2010

The adhesive effects of three adhesion promoters were compared utilizing three different filled resins on acid-etched human permanent teeth. The results demonstrated a significantly greater resistance to dislodgement of resins by shear forces when an NPG-GMA type of adhesion promoter was utilized. Type of resin did not influence resin retention.
Alkaline Phosphatase Activity in a Strain of Bacterionema Matruchotii
Authors: Franker Colin K. , Mcgee Marlon P. , Rezzo Thomas P.
Published: November 2010

Protein from the soluble fraction of Bacterium matruchotii cells propagated in a medium containing no added inorganic phosphate was fractionated by gel permeation chromatography. The bulk of phosphatase activity assayed at pH 8.0 was found in fractions equivalent to a molecular weight of 6 × 105 daltons. Substrate saturation kinetics indicate at Km of 0.75 mM for p-nitrophenylphosphate. Activity was stimulated more than twofold by Zn++ at 1 mM, but was significantly reduced by EDTA, Ca++ and inorganic phosphate. The enzyme(s) shows negligible activity at pH below 6.0 and has a narrow optimum between 7.5 and 8.5.
Antibacterial Susceptibility of Plaque Bacteria
Authors: Newman Michael G. , Hulem Charles , Colgate Judith , Anselmo Carl
Published: November 2010

Selected anaerobic, capnophilic and facultative bacteria isolated from patients with various forms of periodontal health and disease were tested for their susceptibility to antibiotics and antimicrobial agents. Specific bactericidal and minimum inhibitory concentrations were compared to disc zone diameters, thereby generating new standards for the potential selection of antimicrobial agents.
New Amine Accelerators for Composite Restorative Resins
Authors: Brauer G.M. , Dulik Dianne M. , Antonucci J.M. , Termini D.J. , Argentar H.
Published: November 2010

The overall characteristics of the composites cured with a number of newly synthesized, tertiary aromatic amines compare favorably to those of resins polymerized with commonly used accelerators. Maximum compressive and tensile strength for the composites are obtained only over a narrow concentration range of accelerator used.
In vitro Wear of Microfilled and Visible Light-cured Composites
Authors: Fan P.L. , Powers J.M. , Craig R.G.
Published: November 2010

Wear of microfilled composites, a visible light-cured composite, and a conventional composite were characterized by two-body abrasion and single-pass sliding. There were differences in abrasion rates among the materials. Tangential forces, wear track widths, and surface failure modes were different among materials. Wear characteristics are combinations of these properties.
Collagenolytic Activity of Crevicular Fluid and of Adjacent Gingival Tissue
Authors: Golub Lorne M. , Kaplan Robert , Mulvihill James E. , Ramamurthy N.S.
Published: November 2010

The fluid in and gingival tissue lining periodontal pockets were collected from male patients undergoing periodontal therapy. The collagenolytic activity of the crevicular fluid, and the ability of the gingiva in culture to degrade (a) an exogenous collagen substrate, and (b) endogenous collagen newly synthesized and labeled with H3 -hydroxyproline, were related to the severity of gingival inflammation. Although inflammation appeared to have only a slight effect on gingival collagenolytic activity and on the turnover of collagen newly synthesized in culture, a marked effect was observed on the collagenase activity in the crevicular fluid. This study suggests that the collagen destructive activity of the periodontal lesion can be assessed by monitoring crevicular fluid collagenolytic activity.
Clinical Performance of Amalgam as Predicted by Physical Property Tests
Authors: Gale E.N. , Osborne J.W.
Published: November 2010

For a number of years, dentistry has relied upon laboratory data to select and to certify the materials to be used in restorations. The data obtained from laboratory studies are used as criteria for clinical performance and also for sales promotion.
Subcutaneously Implanted Alginate as a Continuous-release Source of Fluoride
Authors: Whitford Gary M. , Ekstrand Jan , Callan Richard S. , Pearson David E.
Published: November 2010

The fluoride concentrations of seven brands of alginate ranged from 8600 to 30,500 ppm. In acute and chronic in vivo studies, fluoride was continuously released from subcutaneously implanted alginate cylinders for up to three weeks. This technique is a simple and economical method for elevating soft and hard tissue fluoride levels.
In vivo Remineralization Using a Sustained Topical Fluoride Delivery System
Authors: Abrahams Lewis J. , Yonese Masa , Higuchi William I. , Fox Jeffrey L. , Charbeneau Gerald T.
Published: November 2010

The efficacy of a new remineralization system was determined in vivo by maintaining a low concentration of approximately 1 ppm fluoride for 48 hrs against a demineralized human tooth. Human subjects were selected who wore removable partial dentures containing two or more of the demineralized teeth with film system. The findings indicate levels of fluoride uptake to 500 ppm at 50 micron depths in experimental sites.
Basic Biological Sciences
Authors: Baum Bruce J. , Wright William E.
Published: November 2010

A major extracellular protein of cultured adult human gingival fibroblasts was shown to be fibronectin by indirect immunofluorescence, lactoperoxidase catalyzed iodination and metabolic radiolabeling. Fibronectin preparations from these cells possessed the biological properties of agglutination of sheep red blood cells and promotion of cell adhesion to a collagen substrate.Received for publication December 18, 1978. Accepted for publication May 21, 1979.
An Abrasion Test for Composite Resins
Authors: Ehrnford Lars , Derand Tore , Larsson Lars-Ake , Svensson Alvar
Published: November 2010

An abrasive wear test for composite resins was proposed. A slurry of glass pearls and abrasive particles were used. The abrasive effect was examined for different particle sizes. Particle sizes were found which gave the same order of wear as found clinically for an amalgam, a composite resin, and unfilled resin.
The Pathway of Enamel Rods at the Base of Cusps of Human Teeth
Authors: Skobe Ziedonis , Stern Samuel
Published: November 2010

Enamel increases in volume and surface area with distance from the dentin-enamel junction, particularly at cusps, while the number of rods remains constant. Our results indicate that the increase in volume may be due to the increased rod diameter near the tooth surface, a circumferential winding of rods in the parazone orientation of Hunter-Schreger bands, and the migration of rods from a mid-coronal origin at the dentin surface to a cuspal termination at the tooth surface. Increased surface area can be explained by the increased rod diameter and the oblique approach of rods to the tooth surface.
Marginal Fracture of Amalgam: Effect of Type of Tooth and Restoration Class and Size
Authors: Mahler David B. , Marantz Richard L.
Published: November 2010

In this study of the marginal fracture of clinical amalgam restorations, it was found that restoration class or size did not influence fracture behavior, and a contralateral pair design was not found to be necessary. However, a slight effect was found for tooth type.
In vivo and in vitro Study of 90Sr in Developing Rat Molar Enamel
Authors: White B.A. , Deaton T.G. , Bawden J.W.
Published: November 2010

The uptake patterns of 90Sr in developing rat molar enamel were studied in vivo and in vitro. Autoradiographic methods were used that preclude loss or translocation of tracers associated with water-soluble compounds in the sections. In eight-day-old rats injected with the tracer, 90Sr uptake in the enamel was significantly less than for dentin and bone, particularly at early sacrifice times. The uptake pattern of 90Sr was somewhat different from that previously observed for 45Ca. The in vitro experiments indicated that the viable intact enamel organ limits uptake of 90Sr by enamel in both the secretory and maturation phases of enamel formation.
Relationship Between Saliva and Serum Agglutination Titers and Post-irradiation Caries Activity in Cancer Patients
Authors: Brown Lee R. , O'Neill Peggy A. , Dreizen Samuel , Handler Sandra F. , Riggan Linda J. , Perkins Deborah H.
Published: November 2010

Agglutination titers in 444 saliva and 481 serum samples from 36 head and neck cancer patients and 16 control subjects were determined against formalinized cellular antigens of Streptococcus and Lactobacillus species. Saliva agglutination titers were significantly higher in cancer patients before radiotherapy than in control subjects. Changes in specific saliva agglutination titers to oral isolates following radiotherapy reflected changes in saliva IgA and post-irradiation caries activity. Patients with no post-irradiation caries activity had significantly higher saliva agglutination titers to S. mutans, S. sanguis, and L. fermenti, lower plaque S. mutans counts, and higher saliva IgA levels than those with post-irradiation caries activity. Serum agglutination titers were unrelated to either serum immunoglobulin levels, microbial counts, or caries activity.
Visco-elastic Properties of Pour (Fluid) Denture Base Resins
Authors: Barsby M.J. , Braden M.
Published: November 2010

A number of pour-type denture base resins were found to have low glass transition temperatures, indicating a propensity to thermal distortion. These low transition temperatures reflected high residual monomer contents. Furthermore, such materials exhibited high mechanical loss tangents, consistent with high creep rates observed previously.
Fluoride Accumulation by Oral Microorganisms
Authors: Gaugler Robert W. , Minke P.N. , Pecotte J.K.
Published: November 2010

Ten laboratory strains of oral microorganisms and 17 recent clinical isolates were examined for their ability to concentrate fluoride from a 1 ppm (0.05 mM NaF) fluoride solution. The laboratory strains concentrated the ion from two- to six-fold over the surrounding media. Clinical isolates of Actinomyces concentrated the ion to similar levels to the laboratory strains of this organism; however, clinical isolates of Streptococcus mutans and S. sanguis concentrated the fluoride significantly less than any of the laboratory strains examined.
Age-related Changes in the Cellular Level of Amylase and Protein Synthesis in the Rat Parotid Gland
Authors: Kim Sun-Kee
Published: November 2010

Age-related changes in the cellular content of secretory proteins and protein synthesis were studied in parotid glands of rats of various ages. The secretory protein content (determined by measuring the level of α-amylase activity) and the synthesis of proteins (assayed by the rate of incorporation of 3H-leucine into acid-insoluble proteins) decline with increasing age. Morphological and radioautographic studies of the gland indicate that the decline in protein synthesis is due to the reduction in the ability of secretory cells to synthesize proteins.
Susceptibility of Rats, Hamsters, and Mice to Carious Infection by Streptococcus mutans Serotype c and d Organisms
Authors: Ooshima Takashi , Sobue Shizuo , Hamada Shigeyuki , Kotani Shozo
Published: November 2010

Susceptibility of rats, hamsters, and mice to carious infection by S. mutans serotypes c and d was compared. S. mutans serotype c induced a similar level of carious lesions at experimental periods of 68, 82, and 98 d in rats, hamsters, and mice, respectively. On the other hand, S. mutans serotype d developed a high level of caries at those experimental periods in rats and hamsters, whereas in mice it showed weak caries activity.
Clinical Science
Authors: Brin Ilana , Koyoumdijsky-Kaye Edith
Published: November 2010

The C/R ratio of lower premolars, which succeeded prematurely extracted primary molars, was examined after apical closure. This ratio was influenced differently in both sexes (more in girls), depending on the age at which the extraction was performed (mainly before the age of eight yr).
Newer Local Anesthetics and Techniques for Administration
Authors: Gangarosa Louis P.
Published: November 2010

Bupivacaine and etidocaine are long-duration amide local anesthetics and could be useful in dentistry for long procedures and post-operative pain control.

Iontophoresis of lidocaine-epinephrine will also add to the dentist's armamentarium by providing a truly effective topical anesthetic for pre-injection topical, deciduous tooth extraction and biopsies. This technique could provide a breakthrough for eliminating patient fear of needle injection, a major factor in patient anxiety which hinders acceptance of dentistry.
Immunoglobulin Class of Agglutinins to Oral Microorganisms in Post-irradiation Cancer Patients
Authors: O'Neill P.A. , Brown L.R. , Dreizen S. , Riggan L.J. , Handler S.F. , Perkins D.H.
Published: November 2010

Previous studies of xerostomic patients showed salivary IgA values and agglutination titers against Streptococcus mutans to be inversely related to plaque levels of the microorganism and post-irradiation caries activity. Chromatographic separation of the samples allowed examination of this agglutination activity for immunoglobulin correlation and antigenic specificity. Serum activity was related to all the major immunoglobulins, with prominence from polymeric IgA. Salivary activity was restricted to the 11S IgA-IgM region. An unidentified, very high molecular weight salivary component agglutinated Lactobacillus fermenti in addition to S. mutans.
Yield Point of Monkey Mandible
Authors: Reitzik M. , Schmidt E. , Butters R.G.
Published: November 2010

Stress-strain curves were developed for monkey mandibles using an Instron Tensiometer. It was found that the yield point (elastic limit) was proportional to the breaking load.
Intraoral Mineralization of Abraded Dental Enamel
Authors: Brudevold F. , Tehrani A. , Bakhos Y.
Published: November 2010

The iodide permeability (Ip) of abraded bovine enamel increased after short exposure to an acid buffer and decreased after short exposure to a mineralizing solution. Intraoral exposure gave a marked decrease in Ip after one h and a continued lesser decrease after two and three h. In vitro exposure to fresh and dialyzed saliva and various undersaturated solutions indicated that the intraoral decrease was due to mineralization rather than to pellicle formation. Analysis of the data also indicated that part of the mineral formed intraorally was more loosely bound to the enamel than that formed from an inorganic mineralizing solution. The rapid rate of the initial phase of intraoral mineralization shown in this study reveals a powerful mechanism for protecting the dentition against demineralization.
Regulation of the Growth Rate of Streptococcus mutans
Authors: Cuffini A. , Kral T.A. , Daneo-Moore L.
Published: November 2010

Streptococcus mutans strain GS-5 was grown under a variety of environmental conditions in order to achieve different balanced growth rates. A range of growth rates could be obtained using limitations in the concentrations of glutamate/glutamine, leucine, or valine. Different balanced growth rates were also obtained when cells were grown in a variety of carbon sources. Using glucose, cellobiose, amygdalin, maltose, mannitol, and galactose, reproducible doubling times were obtained ranging from 61 to 226 min.
Role of the Enamel Organ in Limiting Fluoride Uptake During the Maturation Phase of Enamel Development
Authors: Bawden J.W. , Deaton T.G. , Crenshaw M.A.
Published: November 2010

Autoradiographs of molar teeth from 15-day-old rats that had been injected with 18F showed no tracer uptake in the late-mineralizing enamel. Autoradiographic and quantitative in vitro experiments indicated that the enamel organ limited fluoride uptake during the maturation phase of enamel formation.
Copper-free Amalgams: Dimensional Change After Approximately Five Years at 60, 37, and 23°C
Authors: Paffenbarger G.C. , Rupp N.W. , Patel P.R.
Published: November 2010

Two copper-free amalgams expanded excessively after storage in air at 60°C for about five yr. One expanded significantly at 37°C and slightly at 23°C. High silver content, absence of copper, and presence of small amounts of zinc, or all three, seemed to promote very high expansions at 60° C.
Relationship Between Subsurface Damage and Wear of Dental Restorative Composites
Authors: McKinney J.E. , Wu W.
Published: November 2010

Pin and disc wear measurements were made on a commercial dental composite over a stress range from 2.5 to 20 MPa. The wear rates were found to increase suddenly during wear at times which tended to decrease with increasing stress. The results are interpreted in terms of wear mode conversion which results from the build-up of subsurface damage during wear. Micrographs showing damaged layers are compared with those from restorations worn in vivo.
Basic Biological Sciences
Authors: Yankell S.L. , Moreno O.M. , Saffir A.J. , Lowary R.L. , Gold W.
Published: November 2010

Solutions containing 0.2% of a bis-biguanide, chlorhexidine (positive control), and four bis-amidinourea antimicrobial agents were tested in beagle dogs in a 12-week study. The five agents significantly reduced clinical plaque and gingivitis scores, and gingival fluid volumes in treated dogs, compared with water. All compounds reduced the stain area scores compared to water controls. Stain intensity scores were higher for chlorhexidine than for the four new antimicrobial agents and the water controls. There were no overt behavioral changes. Histological examination of oral tissues revealed no irritation.
Human Interdental Plaque-pH Data and Rat Caries Tests: Results with the Same Substances
Authors: Firestone A.R.
Published: November 2010

Interdental plaque-pH telemetry measures, in vivo, H-ion concentration at the level of the enamel surface under an undisturbed layer of plaque. It is better suited to test non- or hypo-acidogenic products than are rat caries tests. These products can, with a very high probability, be considered non- or hypocariogenic ("safe, or friendly, for teeth "), no matter how frequently they are consumed.

Plaque-pH telemetry is poorly suited for judging the effectiveness of agents directed at enamel - e.g., topical fluoride, remineralizing solutions, etc. - or agents which may have long-term effects on plaque composition.

Plaque-pH telemetry is able to demonstrate the effects of different meal patterns and the form and texture of foods on oral clearance and plaque pH.
The Effect of Several Topical Fluoride Agents on Artificial Lesion Formation
Authors: Wefel J.S. , Harless J.D.
Published: November 2010

NH4F, Na2SnF6, and TiF 4 were applied to human molars before in vitro lesion formation. Polarized light microscopy was used to evaluate the lesions formed; it showed that only the TiF4 treatment resulted in a reduction in lesion size when compared to APF test halves.
Estimation of Solidification Time During Casting by Use of a Heat Transfer Model
Authors: Okazaki M. , Takahashi J. , Kimura H. , Ida K.
Published: November 2010

Time-dependent temperature profiles in dental casting molds were analyzed by an unsteady heat conduction model. The thermal conductivity and initial temperature of the mold greatly affected the heat transfer in the mold. The thermal conductivities of gypsum-and phosphate-bonded investments at high temperatures were accurately measured by means of the hot wire method. From the data obtained, the solidification times of Ag, Ag alloy, and Co-Cr alloy were calculated and compared with the experimental results.
A Low-gold Dental Alloy: Structure and Segregations
Authors: Herø H. , Jørgensen R. , Sørbrøden E.
Published: November 2010

The structure and concentration gradients were studied in the as-cast state for a low-gold alloy and a conventional Type III gold alloy. A much more lamellar eutectic phase was found at the grain boundaries in the low-gold alloy. TEM investigations showed that the interior of the grains consisted of fine lamellae, which probably were alternating Au-Ag and Au-Cu-rich bands due to the miscibility gap in the solid state. Microprobe analyses, where the beam overlapped several of the observed lamellae, displayed both the inter-dendritic and grain boundary segregations to be much larger for the low-gold alloy than for the Type III alloy. The lamellae observed in the as-cast state are quickly dissolved at 700°C into one phase, but the relaxation by diffusion of the concentration differences associated with grain boundary segregations required several hours because of the much larger distances involved. Aging at 350°C caused precipitation of ordered fct particles. On the basis of structure and alloy composition, they are most likely AuCu I and may contain some Pd.
Development of an Artificial Oral Environment for the Testing of Dental Restoratives: Bi-axial Force and Movement Control
Authors: DeLong R. , Douglas W.H.
Published: November 2010

The integration of two closed mechanical loops was used to produce a force-movement cycle, using servo-hydraulics. Several of the parameters were of interest in clinically-simulated laboratory studies. The system represented the first phase in developing an artificial oral environment.
The Ultrastructure and Hardness of the Transparent of Human Carious Dentin
Authors: Ogawa K. , Yamashita Y. , Ichijo T. , Fusayama T.
Published: November 2010

The ultrastructure of the transparent layer of carious dentin was investigated in relation to hardness. This layer was the deeper part of the intermediately-softened inner carious dentin. Intratubular deposition of fine crystals was initially observed at the uppermost layer of normal dentin, increased in the subtransparent layer, and gradually shifted to deposition of rhomboid-shaped crystals in the transparent layer. Crystals were not seen in the tubules in the overlying discolored layer. Softening, due to demineralization of the intertubular and peritubular dentin, started at the bottom of the subtransparent layer and increased in the outward direction.
Changes in Protein Composition of Saliva from Radiation-induced Xerostomia Patients and Its Effect on Growth of Oral Streptococci
Authors: Cowman R.A. , Baron S.S. , Glassman A.H. , Davis M.E. , Strosberg A.M.
Published: November 2010

Clarified and dialyzed mixed saliva-water rinses, obtained from patients receiving radiation treatment of the major salivary glands, exhibited quantitative reductions in total protein content and qualitative changes in protein composition. Radiation or post-radiation saliva preparations supported enhanced growth of Streptococcus mutans, but reduced growth of Streptococcus sanguis relative to growth on pretreatment saliva.
Extensibility Characteristics of the Human Cheek: A Pilot Study
Authors: Weinstein S. , Ho T.P. , Bowley W.W. , Boyle M.
Published: November 2010

Force displacement curves of the cheek in an edentulous area in the maxillary bicuspid-molar region on ten adults evidenced three segments: a power function, a plateau, and an exponential function. The plateau suggested an area in which the cheek could be displaced with no increase in force. The resting force was 1.54 g to 4.61 g. The cheek can be modeled by a fluid-filled double elastic membrane system.
Development of High-strength, Acrylic Resin-compatible Adhesive Cements
Authors: Brauer G.M. , Stansbury J.W. , Argentar H.
Published: November 2010

The reaction of vanillate esters dissolved in chelating agents with zinc oxide yields hard cementitious materials. Hexyl vanillate-EBA(o-ethoxybenzoic acid) mixed with ZnO-Al 2O3-hydrogenated rosin gives a high-strength, low water-soluble cement that does not inhibit polymerization and adheres to non-precious metals and composites.
Cutaneous Sensory Thresholds from Skin Overlying Masseter and Forearm in MPD Patients and Controls
Authors: Davidson R.M. , Gale E.N.
Published: November 2010

Cutaneous sensory thresholds from skin overlying both masseters and right ventral forearm were measured in a group of 12 MPD patients and an appropriately matched group of non-patients. No significant differences were found between the two groups, nor were there significant differences between symptomatic and contralateral asymptomatic sites in the patients. There does not appear to be evidence for differences in sensory characteristics in the cutaneous afferent pathway of MPD patients.
Analysis of Thermally-induced Stresses in Porcelain-Metal Systems
Authors: DeHoff P.H. , Anusavice K.J. , Boyce R.J.
Published: November 2010

An analysis of the stresses which develop during air cooling and shock testing of a simulated porcelain-metal crown is presented. Strain gauges were used to experimentally determine porcelain surface stresses during shock testing. The finite element method was used to calculate stress patterns throughout the simulated crown. This study indicates that the previously reported high degree of correlation between dilatometry-derived compatibility index values and ΔT values may be related to porcelain tensile strengths and defect density.
Collagenase Activity in Human Saliva
Authors: Jima K. , Ando K. , Kishi M. , Nakashizuka T. , Hayakawa T.
Published: November 2010

Fairly high collagenase activity was initially demonstrated in human whole saliva, and the activity from patients with periodontal diseases was statistically higher than that from healthy subjects. Based on some characteristic properties, the collagenase in whole saliva appeared to be of tissue, rather than bacterial, origin.
A Simplified Technique for the Evaluation of Circulation in Experimental Osseous Grafts
Authors: Petri W.H. , Halverson B.A. , Triplett R.G.
Published: November 2010

A technique has been described that is effective in the evaluation of microcirculation in experimental bone grafts. This method employs India ink with a perfusion pump. These materials provide an inexpensive, rapid, and simple protocol that yields consistent, repeatable results with graphic demonstration of microcirculation in experimental bone grafts.
The Effect of Mastication on Marginal Adaptation of Composite Restorations in vivo
Authors: Qvist V.
Published: November 2010

The marginal adaptation of composite restorations placed in vivo in acid-etched cavities in teeth with and without antagonists was compared. The results showed that functional mastication has a major influence on the marginal adaptation of composite restorations in the oral environment and must therefore be considered in the planning of future leakage experiments.
An X-ray Spectrometric Technique for Measuring Porcelain-Metal Adherence
Authors: Ringle R.D. , Mackert J.R. , Fairhurst C.W.
Published: November 2010

This study demonstrated a correlation between silicon x-ray counts and area fractions of adherent porcelain as determined by point-counting. This correlation has allowed a method to be devised for measuring area fractions of porcelain adherent to porcelain-fused-to-metal (PFM) fracture surfaces. The described method, after controlled destruction of the porcelain mass, uses silicon x-rays excited by the electron beam in a scanning electron microscope. Under the conditions employed in these studies, the x-ray technique has shown that this gold alloy retains more porcelain than does either of two particular nickel-chromium alloys.
Neuraminidase-activated Attachment of Actinomyces naeslundii ATCC 12104 to Human Buccal Epithelial Cells
Authors: Saunders J.M. , Miller C.H.
Published: November 2010

The attachment of Actinomyces naeslundii ATCC 12104 to human buccal epithelial cells pre-treated with neuraminidase (sialidase) was evaluated. Both commercial clostridial neuraminidase and neuraminidase preparations from the test strain of A. naeslundii enhanced attachment. The results suggest that the A. naeslundii β-galactoside-seeking ligand involved in hemagglutination and interbacterial coaggregation also mediates one type of binding to human buccal epithelial cells.
Grooved Titanium Surfaces Orient Growth and Migration of Cells from Human Gingival Explants
Authors: Brunette D.M. , Kenner G.S. , Gould T.R.L.
Published: November 2010

A silicon mask-etching technique was used to prepare grooved surfaces that control the direction of outgrowths of human gingival explants. The method used to produce the grooves is excellent in terms of both the uniformity of the grooves and the control with which surfaces of the desired specifications can be obtained.
Bovine Teeth as Possible Substitutes in the Adhesion Test
Authors: Nakamichi I. , Iwaku M. , Fusayama T.
Published: November 2010

In order to find a substitute for human teeth in the adhesion test, the adhesive strength to bovine teeth was compared with that to human teeth using five dental cements and two composite resins. The adhesion to enamel and the superficial layer of dentin showed no statistically significant difference between human and bovine teeth, although the mean values were always slightly lower with bovine teeth. Adhesion to bovine dentin decreased considerably with the depth of dentin.
Distribution of Enamel Defects and the Association with Respiratory Distress in Very Low Birthweight Infants
Authors: Johnsen D. , Krejci C. , Hack M. , Fanaroff A.
Published: November 2010

Although dental defects have long been observed among surviving pre-term infants, only few systematic studies address this problem. In a clinic limited to recall of infants of very low birthweight (<1.5 kg), enamel hypoplasia of primary incisors was found in 14/67 (21%) children, and enamel opacities were found in an additional 31% of the children. In contrast, enamel hypoplasia and opacities were found in 4% and 22%, respectively, of a control group of 46 normal birthweight children. The difference was significant (p < 0.05) for the hypoplasia but not for the opacities. Primary incisor enamel hypoplasia was more commonly noted in maxillary central incisors than in lateral incisors (X2 = 28.0, p < 0.01). Furthermore, hypoplasia was more common in maxillary incisors than in mandibular incisors (X2 = 48.4, p < 0.01).

In infants with dental defects, there was no significant correlation with pregnancy risk factors, gestational age, birth weight, septicemia, first-week caloric intake, serum bilirubin, or calcium. Infants with enamel hypoplasia were more likely, however, to have severe respiratory distress syndrome (X2 = 7.2, p < 0.01), than infants with unaltered enamel.

Central incisor edge involvement may indicate post-natal processes and/or a systemic disturbance extending back to the middle trimester of pregnancy.
Thymocyte Activating Factor(s) in Human Gingival Fluids
Authors: Mergenhagen S.E.
Published: November 2010

Human gingival fluid contains a low-molecular-weight factor (10,000 to 25,000) which enhances the proliferation of murine thymocytes in the presence of suboptimal doses of mitogen. Although the gingival fluid has no Interleukin 2 (T cell growth factor) activity, as indicated by its inability to induce proliferation of an IL 2 dependent lymphocytic cell line, it is directly mitogenic for dermal fibroblasts. These studies suggest that the thymocyte and fibroblast growth-promoting properties of human gingival fluid may have important functions in regulating inflammatory responses in the human periodontal tissues.
A Freeze-Fracture Study of Ruffle-ended Post-secretory Ameloblasts
Authors: Garant P.R. , Nagy A. , Cho M.I.
Published: November 2010

The post-secretory portion of the rat incisor enamel organ was prepared for routine transmission electron microscopy and freeze-fracture replication in order to define further the structural surface features of the ruffle-ended ameloblasts. Surface views of the distal plasma membrane of the ruffle-ended ameloblasts revealed a well-developed zonula occludens junction with from six to ten rows of tight junctional strands. Gap junctions were also observed just proximal to the tight junctional strands. The membranes of the ruffled border contained a rich supply of intramembrane particles (IMP). The IMPs were approximately 7 to 8 nm in diameter and preferentially located on the P-face profiles of the membrane. The density of IMPs on the membranes of the ruffled border was higher than that on the lateral borders of the cell.

It is suggested that the IMPs of the ruffled border may represent enzymatic proteins in the basal cell membrane of absorptive ameloblasts. In addition, the large, highly-developed zonula occludens appeared structurally capable of sealing the intercellular spaces between the ruffle-ended ameloblasts.
Effects of Local Anesthetics on Pulpal Blood Flow in Dogs
Authors: Kim S. , Edwall L. , Trowbridge H. , Chien S.
Published: November 2010

Effects of 2% lidocaine with epinephrine (1 :100,000) administered by the various local anesthetic techniques - i.e., infiltration, mandibular block, and intraseptal injection - on pulpal blood flow in dogs were determined using the 15 μm radioisotope-labeled microsphere injection method. The pulpal blood flow decreased significantly with all three techniques; however, the most drastic reduction occurred in the molar teeth with the intraseptal injection. When 2% lidocaine without epinephrine was used in the intraseptal injection, pulpal blood flow increased significantly.
Post-treatment Effect of Fluoride Varnishes in Children with a High Prevalence of Dental Caries in a Community with Fluoridated Water
Authors: Seppa L. , Tuutti H. , Luoma H.
Published: November 2010

Children with a high prevalence of dental caries living in a community with fluoridated water had received semi-annual half-mouth applications of one of two fluoride varnishes for three years. Two years after the applications were discontinued, we studied the post-treatment effect of the varnishes. The absolute reduction in caries found during the treatment was retained, but the cariostatic effect did not continue after treatment. This finding suggests that fluoride varnish applications should not be discontinued after three years.
Electromyographic Activity of Anterior Temporal Area Pain Patients and Non-pain Subjects
Authors: Majewski R.F. , Gale E.N.
Published: November 2010

Anterior temporal area and non-specific facial muscle activity were recorded from 11 patients with unilateral anterior temporal area muscle pain and from 11 matched asymptomatic individuals at various mandibular openings. No significant differences were observed (1) in temporal area EMG activity between pain and non-pain sides and (2) between temporal area and non-specific facial muscle EMG activity between patient and non-patient groups.

In relation to increased vertical mandibular opening from centric occlusion: (a) anterior temporal area EMG activity decreased to a minimum level (with further opening, anterior temporal area EMG did not significantly change); and (b) non-specific facial muscle EMG activity decreased to a minimum level (with further opening, non-specific facial muscle EMG increased).