bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Calcifiable Proteolipid from Streptococcus mutans
Authors: Streckfuss J.L. , Vogel J.J. , Brown L.R.
Published: November 2010

Proteolipid is known to initiate calcification in vitro. Apoprotein and phospholipid components of proteolipid from five of 14 calcifiable S. mutans specimens were characterized. The apoproteins contained 16 amino acids with calculated percent polarities ranging from 32.0 to 45.2. The acidic phospholipids were cardiolipin, mono- and diphosphoinositides, and phosphatidylserine. Neutral lipids, phosphatidylethanolamine and phosphatidylcholine, were also found. The latter were the most abundant in all isolates. Appropriate hydrophobic proteins and acidic phospholipids in the proteolipids accounted for S. mutans calcifiability.
Autoradiographic Determination of the Metabolic Activity of Protein in Mature Dentin
Authors: Hoppenbrouwers P.M.M. , Borggreven J.M.P.M. , Maltha J.C.
Published: November 2010

Tritiated proline was administered as protein marker to domestic cats during the development of their permanent dentition (age 11-18 wk). At 30, 43, 56, and 75 wk, the amount of tritium in the mature dentin was determined by quantitative autoradiography. At 43, 56, and 75 wk the residual amount of label was 92, 92, and 77%, respectively, of that at 30 wk. The metabolism of dentinal collagen (with possibly a recycling of proline) and the metabolism of non-collagenous proline-containing proteins are suggested as factors that may contribute to the decrease of tritium label.
Salivary Anti-Streptococcus mutans Changes over a Six-month Period in Children Ages Two - Five Years
Authors: Everhart D.L. , Bamgboye P.O. , Schwartz M.S.
Published: November 2010

Fourteen children, from two to five years of age, were surveyed at two periods: the first on day zero before carious lesions were filled; and the second at six mo after filling carious lesions. The variables surveyed were salivary IgA specific for S. mutans, oral hygiene, caries experience (deft), age, and saliva flow rate. The findings indicate a three-fold increase in salivary IgA specific for S. mutans during the six-month period.
Salivary Protein Polymorphisms in Caries-free and Caries-active Adults
Authors: Anderson L.C. , Lamberts B.L. , Bruton W.F.
Published: November 2010

Several salivary proteins are known to exhibit genetic polymorphism, and this study was undertaken to determine whether there was an association of caries experience with specific parotid salivary protein phenotypes. Parotid saliva collected from 46 caries-free and 47 caries-active naval recruits was subjected to SDS, anionic, and cationic polyacrylamide slab gel electrophoresis. Distributions of the acidic proline-rich (Pr), parotid acidic (Pa), double band (Db), parotid size variant (Ps), parotid middle band (Pm), and parotid basic (Pb) protein phenotypes were similar in both caries-free and caries-active subjects. Further, overall protein patterns on SDS, anionic, and cationic slab gels did not differ between the two groups.
Properties of Cysteine-containing Phosphoproteins from Human Submandibular-sublingual Saliva
Authors: Shomers J.P. , Tabak L.A. , Levine M.J. , Mandel I.D. , Hay D.I.
Published: November 2010

Cysteine-containing phosphoproteins (CCP) similar to those found in human submandibular-sublingual saliva have also been detected in parotid saliva and tears suggesting a serous origin. No appreciable difference was found in salivary CCP concentrations between caries-susceptible and caries-resistant individuals. CCPadsorbed to hydroxyapatite, and this binding was due in part to phosphate residues. In addition, these molecules inhibited the transformation of dicalcium phosphate dihydrate, albeit to a lesser extent than statherin.
Transformation of Calcium Fluoride for Caries Prevention
Authors: Chander S. , Chiao C.C. , Fuerstenau D.W.
Published: November 2010

Oral application of fluoride for caries prevention may tend to form calcium fluoride (CaF2) instead of the desired fluorapatite. In view of this, the transformability of CaF2 to fluorapatite has been studied. This investigation shows that CaF2 can be converted to fluorapatite in phosphate solutions at various temperatures ranging between 25 and 75°C in the pH range of 6.5 to 8.5. In the initial stage, phosphate ions, believed to be HP04=, adsorb on the particle surface. A dissolution/precipitation mechanism is proposed for the growth of fluorapatite.
The Use of an Intermediate Resin in the Acid-etch Procedure: Retentive Strength, Microleakage, and Failure Mode Analysis
Authors: Prevost A.P. , Fuller J.L. , Peterson L.C.
Published: November 2010

Three composite resin systems, one conventional (Concise) and two microfilled (IsoPast and Silar), used with and without an intermediate resin (Concise Enamel Bond), were evaluated with and without thermal stress for in vitro retentive strength and sealing ability to acid-etched human enamel.

All three materials yielded significantly different shear strength values. The use of an intermediate resin significantly improved both the shear strength and resistance to microleakage of Silar, while no differences were observed for Concise and IsoPast. The thermocycling procedure did not generally or consistently affect the results.

The failure mode of the three acid-etched composite resins was studied by evaluation of the failure surface and by describing the percentages of enamel, composite, and interface which were present. The use of an intermediate resin did not significantly influence the failure mode, and the correlation between the failure mode and retentive strength, although significant, was low. The study confirmed the importance of adequate wetting action of a resin on the etched enamel surface to ensure proper bonding.
Clinical Science Physical and Chemical Effects of Toothpastes on Dental Enamel
Authors: Zero D.T. , Curzon M.E.J. , Zander H.A.
Published: November 2010

The effects on surface enamel of an experimental toothpaste containing Sr-EDTA, sodium ricinoleate, and fluoride were compared with those of a commercially available fluoride toothpaste. Knoop indentations, before and after treatment with control and experimental toothpastes, showed no significant changes. Both toothpastes rendered the enamel surface less soluble after treatment.
Measurement of Softening Temperatures in Dental Bake-on Porcelains
Authors: Bertolotti R.L. , Fukui H.
Published: November 2010

An effective porcelain softening temperature is determined from the deflection behavior of split bimaterial (metal/porcelain) rings during cooling. The effective temperature provides an upper temperature bound for thermal expansion comparison and compatibility evaluation.
Color Analysis of Dental Modifying Porcelains
Authors: Johnston W.M. , O'Brien W.J.
Published: November 2010

Sintered samples of modifying porcelains of various colors and manufacturers were analyzed using reflectance spectrophotometry. Color designations are reported according to practices of the Commission Internationale de l'Eclairage (International Commission for Illumination), and color names were assigned based on a method developed through a joint effort of the Inter-Society Color Council and the United States National Bureau of Standards (ISCC.NBS). Within samples labeled by the same color, differences among manufacturers were found in the color designations and names. These differences were noted in part by plots of the chromaticity coordinates of the samples. The ISCC-NBS method of designating colors is proposed as a uniform and descriptive color-naming method for modifier porcelain. Consistent color naming is a step in improving communication over the use of modifying porcelains.
Influence of Enamel Stylus Stiffness on the Sliding-wear Behavior of a Composite Restorative
Authors: Rice S.L. , Bailey W.F. , Pacelli P.F.T. , Blanck W.R.
Published: November 2010

The wear behavior of a composite restorative in sliding contact with a stylus fashioned from human enamel has been investigated as a function of the effective stiffness of the stylus-restorative contact. The results demonstrate that: (1) the stiffness parameter affects wear surface morphology of both the composite and the enamel; and (2) a decrease in stiffness produces a larger variance in the rate of wear of a composite, but this factor has no significant effect on the average wear-rate for the material and test conditions explored.
Chemical Location of Cadmium in Developing Rat Molars
Authors: Shearer T.R. , Johnson B.E. , Ridlington J.W. , Whanger P.D.
Published: November 2010

The purpose of this experiment was to determine the distribution and chemical binding of 109Cd in the developing rat molar. The results indicated that cadmium was taken up into the inorganic fraction of molar teeth, and this may help elucidate the mechanism of caries promotion by cadmium.
The Uptake of Horseradish Peroxidase in the Temporomandibular Joint Synovium of the Rat Following Unilateral Extraction of Molars
Authors: Ueno S.
Published: November 2010

Unilateral extraction of rat molars was followed by degeneration of type A temporomandibular joint synovial lining cells. The uptake of intravenously injected HRP decreased in accordance with the degree of degenerative change. Normal passage of proteins from blood to joint cavity appears to be controlled by the synovium, especially by type A cells. This study suggests that, with certain TMJ disturbances, control of protein transport may be altered.
The Relationship Among the Permeability to Iodide, Pore Volume, and Intraoral Mineralization of Abraded Enamel
Authors: Brudevold F. , Tehrani A. , Cruz R.
Published: November 2010

Measurements of the permeability to iodide (Ip) of the outer portion of abraded bovine enamel were found to be related to the pore volume. Intraoral exposure of the enamel produced a rapid decrease in Ip after 0.5 h and a slower decrease during the next three h. This decrease was due to mineralization, and it was shown that the rate of mineralization decreased with a decrease in the pore volume of the enamel.
Pain in Clinical and Laboratory Contexts
Authors: Dworkin S.F. , Chen A.C.N.
Published: November 2010

Subjects served as their own control when tooth pulp shock was delivered in laboratory and clinical situations. Significantly heightened pain was observed in the clinical dental setting. The dental setting proved more anxiety-provoking and associated with reduced tolerance for pain, suggesting that cognitive contexts of a dental setting may elicit heightened subjective pain responses.
Optical Properties of Composites of Selected Shades
Authors: Yeh C.L. , Miyagawa Y. , Powers J.M.
Published: November 2010

The optical properties of seven shades of a conventional composite and five shades of a microfilled composite were determined from reflection spectrophotometric data with Kubelka's equations. Scattering and absorption coefficients decreased and values of infinite optical thickness increased as wavelength increased from 405 to 700 nm. Reflectivity curves were determined.
Arylamidase Activities Specific for Proline, Tyrosine, and Basic Amino Acid Residues in Some Oral Bacteria
Authors: Fukasawa K. , Hiraoka B.Y. , Fukasawa K.M. , Harada M.
Published: November 2010

Arylamidase activities in eight strains of oral bacteria were assayed. Although the activities in S. mutans tested were low, S. mitis, S. milleri, and lactobacilli had high activities. Arylamidases which were specific for proline and basic amino acid residues in S. mitis and tyrosine residue in L. casei were identified.
Characterization of the Adhesion of Soft Lining Materials to Poly (methyl methacrylate)
Authors: Wright P.S.
Published: November 2010

The adhesion of nine soft lining materials to poly (methyl methacrylate) has been characterized in the laboratory using peeling tests. Applying the energy theory of fracture to an elastic film peeling from a rigid substrate, this method gives a direct measure of the work of detachment.
A Model for the Implant-Bone Interface Characteristics of Porous Dental Implants
Authors: Cook S.D. , Klawitter J.J. , Weinstein A.M.
Published: November 2010

The use of computer-aided design techniques, such as,finite element stress analysis, to evaluate implant designs requires that the mechanics at the interface between the implant and the bone be characterized, This problem is aecentuated when implants designed to achieve stabilization by tissue growth into parous coatings are used. A model has been developed to represent the mechanical properties of the porous material-bone interface. The model, which accounts for the mechanics of bane tissue grown into a porous implant surface, was also developed so that it could be incorporated into a three-dimensional finite-element analysis,

The analytical results from a three-dimensional finite-element model af a cylindrical porous rooted dental implant system incorporating the interface madel were compared to the results of mechanical tests performed on similar implants which had resided in canines for two yr. The resutts fram the finite elernent analysts using the interface model were found to be in better agreement with the experimental results than when a direct bone- to-porous-inaterial interface was assumed.
Pulpal Response to a New Adhesive Restorative Resin
Authors: Inokoshi S. , Iwaku M. , Fusayama T.
Published: November 2010

The pulpal response to a new adhesive restorative resin was histopathologically investigated using dogs, and was compared with a representative conventional resin. When filled without etching and cavity wall lining, bacterial penetration and pulpal response were less with the new resin. Lining of dentin walls and total etching of cavity walls, including dentin, caused less pulpal response under the new resin. Cavities which were totally etched and filled with the new resin showed only a slight pulpal response and no bacterial penetration.
Neurotoxic Effects of Root Filling Materials on Rat Phrenic Nerve in vitro
Authors: Brodin P. , Røed A. , Aars H. , ørstavik D.
Published: November 2010

Inhibitory effects of root filling materials on the conduction of action potentials evoked in rat phrenic nerves were evaluated in vitro. Endomethasone and N2 Normal completely and irreversibly inhibited conductance; ProcoSol caused complete but reversible inhibition; Kloroperka N-O caused total inhibition which was sometimes reversed; and AH26 and Diaket showed partial inhibition which was partially reversible.
Acid-soluble Bovine Fetal Enamelins
Authors: Belcourt A.B. , Fincham A.G. , Termine J.D.
Published: November 2010

High molecular weight enamelin proteins were recovered from conventional acetic acid extracts of fetal bovine enamel and were analyzed by gel filtration and ion-exchange chromatography. This procedure is simple and straightforward, and recovers approximately half of the total tissue enamelin content.
Biological Assessments of Experimental Cavity Cleansers: Correlation Between in vitro and in vivo Studies
Authors: Mjor LA , Hensten-Pettersen A. , Bowen R.L.
Published: November 2010

Adhesive bonding of resins to dentin surfaces requires the removal of the layer of debris caused by the cutting. Certain isotonic acidic solutions can do this rapidly. Five solutions were evaluated using cell cultures and pulp studies in monkeys. At concentrations above 10%, each solution caused the cultured human epithelial cells to respond unfavorably, probably due to the low pH of the culture medium. None of these experimental cleanser solutions caused significant pulpal irritation.
Calcium, Phosphorus, Fluoride, and pH Levels of Human Dental Plaque from Areas of Varying Fluoride Levels
Authors: Grobler S.R. , Reddy J. , Van Wyk C.W.
Published: November 2010

Plaque calcium, phosphorus, fluoride, and pH in samples obtained from 149 life-long resident children, aged from six to seven and 12 to 13 yr, from one of three naturally fluoridated communities were determined. In general, smaller amounts of phosphorus and fluoride, and larger amounts of calcium and hydrogen ions (lower pH values) are associated with smaller amounts of fluoride in the drinking water supply. Significant differences among the mean pH, fluoride, and Ca/P concentrations both in the six-to-seven- and 12-to-13-year age group were found when comparing the results of the three areas with different levels of fluoride in their drinking water supply.
Structural, Ultrastructural, Microradiographic, and Electron-probe Studies of an Unusual Case of Regional Odontodysplasia
Authors: Kerebel B. , Kerebel L.M.
Published: November 2010

Structural, ultrastructural, microradiographic, and electron microprobe studies of an unusual case of odontodysplasia were performed. Two cusps were absent from one molar. Normal prismatic enamel and mantle dentin were present on the two others. The dentinal mass resembled osteodentin. The mineral content of enamel and dentin was decreased compared to that of the controls.
Materials Science
Authors: DeHoff P.H. , Anusavice K.J. , Hathcock P.W.
Published: November 2010

An experimental and analytical stress analysis of the four-point flexural test for metal-ceramic bond strength is presented. Specimen geometry dictates whether failure occurs at the porcelain surface or at the interface under a line of force magnification. Finite element stress analysis indicates that bond separation, if.it occurs, is probably due to normal tensile stresses.
Adhesive Bonding of Various Materials to Hard Tooth Tissues: Improvement in Bond Strength to Dentin
Authors: Bowen R.L. , Cobb E.N. , Rapson J.E.
Published: November 2010

Used in sequence, solutions of an acidic mordant, a surface-active comonomer, and a coupling agent having methacrylate and aromatic carboxyl groups were used to prepare dentin surfaces in vitro for strong bonding with a composite resin.
Effect of Chinese and Western Antimicrobial Agents on Selected Oral Bacteria
Authors: Tsao T.-F. , Newman M.G. , Kwok Y.-Y. , Horikoshi A.K.
Published: November 2010

The susceptibility of selected oral bacteria, including suspected periodontopathogens, to a commonly employed Chinese herbal medicine Huang-chin (HC, Scutellaria baicalensis) was tested in vitro. The minimum inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC) were determined. HC was also compared with tetracycline, alexidine, and stannous fluoride. HCdecoction, ata concentration of 2%, was bacteriostatic in eight of 11 bacteria tested, but a concentration of 3.13% or greater was required for bactericidal effect. Among the tested bacteria, Bacteroides melaninogenicus ss intermedius was the most sensitive (MIC = 1.57%, MBC = 2%); Actinomyces viscosus was the least sensitive (MIC = 6.25%, MBC 12.5%). Tetracycline, alexidine, and SnF2 were bactericidal in vitro in all bacteria tested at concentrations lower than those used clinically.
Materials Science
Authors: Yeh C.L. , Powers J.M. , Miyagawa Y.
Published: November 2010

The colors of seven shades of a conventional composite and five shades of a microfilled composite were measured by reflection spectrophotometry at three thicknesses and for two backgrounds. Intrinsic color was determined from reflectirity data computed from optical properties. As thickness increased, the color approached the intrinsic color. Differences in color among shades were statistically significant.
In vitro Depth of Cure of Photo-activated Composites
Authors: Tirtha R. , Fan P.L. , Dennison J.B. , Powers J.M.
Published: November 2010

The in vitro depth of cure of six photo-activated composites was studied by measurement of hardness, transverse strength, and light transmission coefficients. Both Barcol hardness and transverse strength were sensitive techniques for characterizing depth of cure. As a group, the visible light-activated composites had higher values of depth of cure and higher transmission coefficients than did the ultraviolet light-activated composites.
Properties of Ag-Cu-Pd Dispersed Phase Amalgam: Compressive Strength, Creep, and Corrosion
Authors: Greener E.H. , Szurgot K.
Published: November 2010

Dental amalgams fabricated from a dispersion phase consisting of 62%Ag-28%Cu-10%Pd, combined with traditional lathe cut and spherical Ag3Sn alloys, were investigated and compared with commercial Cu-enriched amalgams. High one-hour compressive strength, reduced creep, and significant improvements in corrosion resistance of dispersant and resultant amalgams were obtained.
Action of Drugs, Detergents, and Monomers on Liposomes
Authors: Fujisawa S. , Kadoma Y. , Masuhara E.
Published: November 2010

Interactions of 14 organic compounds, such as phenols, aromatic carboxylic acids, steroids, and methacrylates with the multi-lamellar lecithin-cholesterol liposomes, were monitored in biological systems. It was found that their actions with our artificial liposomes were quite similar to those of biological membranes described previously.
The Pattern of Mineralization of Traumatically-induced Developmental Defects of Sheep Enamel Assessed by Microhardness and Microradiography
Authors: Suckling G.W. , Purdell-Lewis D.J.
Published: November 2010

An earlier study showed that some of the variation in appearance of defects of enamel in sheep incisor teeth induced by trauma during tooth development was related to the phase of activity of the ameloblasts at the time of injury. In the present study, sixteen selected defects were examined by microhardness and microradiography. It was found that in some of the fully formed teeth, the defects had retained the pattern of mineralization present at the time of trauma, i.e., mineralization had ceased. In other teeth, further mineralization of the defects occurred after trauma, resulting in well-mineralized enamel, although sometimes of incomplete thickness. It was concluded that the trauma, depending on its severity, leads to either permanent or temporary dysfunction of the ameloblasts, which also influences the appearance of the resulting lesions.
Streptococcus mutans in Caries-free and Caries-active Naval Recruits
Authors: Walter R.G. , Shklair I.L.
Published: November 2010

Streptococcus mutans was detected by a colorimetric test in all of 53 caries-active naval recruits and in 98 of 120 caries-free (DMFT = 0) recruits. The number of positive sites was greater in the caries-active subjects. The low percentage of false positive and false negative S. mutans isolations confirmed the value of the colorimetric test as a preliminary indicator of S. mutans.
The Continuity of Mandibular Form in Mandibulofacial Dysostosis
Authors: Behrents R.G.
Published: November 2010

It is reported in studies of patients with Mandibulofacial Dysostosis (Treacher Collins Syndrome, MFD) that the lower border of the mandible exhibits a consistent form. The mandible of a 15-week-old fetus was described demonstrating the distinctive typical broad concave curvature of the lower border of the mandible. It appears that the basic mandibular form in MFD is established in utero, is maintained throughout postnatal growth and development, and is unique in shape.
Determination of Visco-elastic Properties of Dental Polymers by Mechanical Impedance Measurements
Authors: Clarke R.L. , Braden M.
Published: November 2010

A mechanical impedance method has been used to determine visco-elastic properties, namely, Young's Modulus (E) and the mechanical loss tangent (Tan δ), at a nominal temperature of 23° C and over the frequency range 0.02 - 20 k Hz. This method involves longitudinal wave propagation in a rod of material, and measuring resonant frequencies and half-band widths. Both glassy and elastomeric polymers have been studied, and data have been compared with low frequency and static data.
Oral Fluoride Retention Following Various Topical Application Techniques in Children
Authors: LeCompte E.J. , Doyle T.E.
Published: November 2010

Eight child volunteers received routine APF gel topical fluoride applications using four different application techniques. Each child received a total of four topical fluoride applications, and all applications were separated by at least one wk. The amounts of fluoride applied, recovered from the mouth, and retained in the mouth were calculated for each treatment. Tray systems with some form of absorptive liner resulted in significantly less oral-retained fluoride after the four-minute application procedure (p<.01). The value of patient expectoration following topical fluoride treatment was also evaluated, and was a significant adjunct in reducing the net oral-retained fluoride dose in eaeh instance (p<.01).
Ethnic Variability in the Prevalence of Submerged Primary Molars
Authors: Koyoumdjisky-Kaye E. , Steigman S.
Published: November 2010

Dental submergence, linked primarily with tooth ankylosis, has been reported to have a possible genetic predisposition. The submergence of primary molars was examined in a sample of 1530 children, 2.5-13.5 yr old, appertaining to seven ethnic groups living in Israel. It was found that the frequency of submergence varied among the ethnic groups, and that, on the whole, it was considerably higher than that in North American children.
Dimensional Changes of a High-tin Content Amalgam
Authors: Paffenbarger G.C. , Rupp N.W. , Patel P.R.
Published: November 2010

Amalgam made with Brewster Alloy (62% Ag, 33% Sn, 5% Cu, and 0.2% Zn) had little or no dimensional change during 24 h at 23°C.

Brewster amalgam stored for five yr in air expanded 186, 68, and 14 μm/cm at 60, 37, and 23°C, respectively.

Nearly "stable" conditions were approached at about 50 mo.
Spectral Distributions of Dental Photopolymerization Sources
Authors: Cook W.D.
Published: November 2010

The spectral distributions of the radiation emitted by the white-light photopolymerization units were measured and were compared with those of a UV light source. The components of short-wavelength radiation were smaller in the former than were those in the latter. The efficiency of the radiation sources for photopolymerization is discussed.
Relationship Between Frequency of Pilocarpine Administration and Salivary IgA Level
Authors: Smith D.J. , Taubman M.A. , Ebersole J.L. , King W.
Published: November 2010

The effect of repetitive administration of pilocarpine nitrate on the salivary volume and salivary IgA concentration was studied in the NIH white hamster. One and one-half to three-fold increases in salivary volume, coupled with decreases of 1/3 to 2/3 in IgA concentration, occurred as the frequency of administration of pilocarpine increased.
Extraskeletal of a Porous Hydroxyapatite Ceramic
Authors: Piecuch J.F.
Published: November 2010

Coralline replamineform hydroxyapatite implants were placed in canine subcutaneous tissues in an attempt to clarify whether the hydroxyapatite matrix acted as a passive matrix for osseous ingrowth when placed in same inherent bone induction capacity.

The implants were well-tolerated and elicited no deleterious host response. Connective tissue rapidly infiltrated the pores, but no evidence of hone formatian was noted in any of the specimens. It was concluded that this implant material does not act to induce bone formation.
Oral Colonization and Pathogenicity of Actinomyces israelii in Gnotobiotic Rats
Authors: Behbehani M.J. , Jordan H.V. , Heeley J.D.
Published: November 2010

Reference strains of A. israelii were orally implanted in germ-free rats after multiple inoculations. Early colonization was associated with areas of interdental hair and bedding impactions. Largest populations of organisms were isolated from teeth, as compared to the tongue, cheek, or palate. Examination of molar teeth with the scanning electron microscope revealed bacterial accumulations in the occlusal fissures, but not on smooth or approximal surfaces. Extensive plaque formation after 100-150 d was accompanied by root-surface caries and bacterial invasion of the pulp. There was no evidence of bacterial penetration of the dentin underlying surface enamel.
Materials Science
Authors: Wiegman-Ho L. , Ketelaar J.A.A.
Published: November 2010

The setting of zinc polycarboxylate dental cements is studied by the measurement of conductance as a function of time. The kinetics can be described by two parameters: an induction period, to, and a first-order reaction rate constant, k, for the decrease of conductance. The influence of molecular weight, temperature, cement-to-liquid ratio, and pre-heat treatment of zinc oxide on both parameters is studied.
Effect of Cement Base Thicknesses on MOD Amalgam Restorations
Authors: Farah J.W. , Clark A.E. , Mohsein M. , Thomas P.A.
Published: November 2010

The effect of five cement bases on the fracture strength of three amalgams was determined at 24 h after condensation. It was found that the type of base used was the most important factor in affecting the fracture strength of the amalgam, followed by the thickness of the base, and finally the type of amalgam that was used.
Aluminum Foil Pouch Packaging in Pre-measured Amalgam Capsules
Authors: Rinne V.W.
Published: November 2010

Examination of the aluminum foil pouch used in some pre-measured amalgam capsules for mercury packaging revealed the formation of an unknown substance after trituration. This substance was determined to be aluminum oxide and, in the amorphous or poorly crystallized hydrated form, may be a contaminate of the amalgam alloy.
Extent of Polymerization of Dental Resins by Differential Scanning Calorimetry
Authors: Antonucci J.M. , Toth E.E.
Published: November 2010

The traditional infrared spectroscopic methods for assessing the degree of polymerization of dental monomers are often hampered by the difficulties of sample preparation and, in the case of composites, by interference from the filler component. These difficulties may be circumvented by the use of another technique, differential scanning calorimetry (DSC). In this preliminary investigation, DSC was used to ascertain the degree of vinyl polymerization of an experimental monomer system consisting of seven parts BIS-GMA and three parts TEGDMA (triethylene glycol dimethacrylate). Thermally-activated polymerizations of this monomer system were studied using benzoyl peroxide (BP) as the initiator. Both the heating rate and the concentration of BP affected the percent of reacted vinyl groups. For a BP concentration of 0.39% and heating rates of 10°/min and 2.5°/min, conversions were 73 and 38%, respectively. Chemically-activated polymerizations using BP and fast-acting amine accelerators (e.g., p-t-butyl-N ,N-dimethylaniline) gave approximately the same results (e.g., 50% conversion) as those obtained with slower-acting promoters (e.g., ascorbyl palmitate). Experimental difficulties are encountered in observing an exotherm with the very reactive accelerators unless the other parameters (e.g., BP or inhibitor content) involved in the reaction are adjusted accordingly. As a method for evaluating the performance of various dental monomers, initiator systems, and inhibitors, DSC has great potential utility.
Leaking of Fillers in Dental Composites
Authors: Soderholm K.-J.M.
Published: November 2010

The leakage of filler elements from four composites after storage in water was investigated. The results showed that all fillers leaked Si, and that the micro-filled composite and the Ba- and Sr-containing glass composites leaked more Si than did the quartz-containing material. The leakage from the different fillers was explained by hydroxy-ion and stress-corrosion attacks.
Three-dimensional Stress Distribution Around a Dental Implant at Different Stages of Interface Development
Authors: Borchers L. , Reichart P.
Published: November 2010

An anchor-type ceramic dental implant contained in a section of the mandibular molar region was modeled for finite element stress analysis. The distributions of stresses in the bone around the implant due to axial and transverse loading were calculated for different stages of normal and pathological development of the implant-bone interface. Highest stress concentrations are observed in the crestal region with transverse loading when spongy bone surrounds the implant immediately after surgery. Development of a lamina dura around the implant slightly reduces severe stress peaks, whereas ingrowth of connective tissue almost eliminates them.
The Acid Pattern in Human Dental Plaque
Authors: Distler W. , Kröncke A.
Published: November 2010

Lactic and volatile acids in standardized plaque samples from 11 subjects have been estimated by means of HPLC before and after exposure to sucrose in vivo. Total acid differed considerably between subjects, but the ratio of acids estimated within the plaque from different persons did not vary significantly. The time-dependent acid pattern following sucrose rinsing allowed the plaque samples to be divided into two groups: one showing only small changes in total acid production; and the other exhibiting a distinct increase in total acid up to 15 min after sucrose rinsing.
Basic Biological Sciences
Authors: MacCallum D.K. , Tandler B. , Lillie J.H.
Published: November 2010

Cytomegaloviruses undergo the classical morphologic stages of replication in hedgehog submandibular gland duct cells. A profound cytomegaly is associated with the infection. These features indicate that the hedgehog may be an excellent model in which to study the biology of cytomegalovirus-salivary gland interactions.
The Initial Alterations in the Craniofacial Complex of Macaca mulatta Skull Resulting from Forces with High-pull Headgear
Authors: Kragt G. , Duterloo H.S.
Published: November 2010

Initial reactions to tensile forces of up to 3.5 N per side applied to the maxilla of a macerated Macaca mulatta skull were determined with holographic interferometry. Displacements ranged from 0 μm to 22 μm depending on the force magnitude and the point of observation. A complicated force-coordinated pattern of shearing and compression in the sutures occurred. The results appear comparable to similar experiments in dry human skulls and analogous to the effects observed in long-term experiments in living animals.
The Solubility of Octacalcium Phosphate at 37°C in the System Ca(OH)2-H 3PO4-KNO3-H2O
Authors: Shyu L.J. , Perez L. , Zawacki S.J. , Heughebaert J.C. , Nancollas G.H.
Published: November 2010

The solubility product of octacalcium phosphate [Ca4H(PO4)3 · 2.5H 2O] has been determined in the system Ca(OH)2-H3PO 4KNO3-H2O at 37°C in experiments involving a range of hydrodynamics, ionic strength, and equilibration time. A value of pK so= 49.3 ± 0.2 was obtained for three different solid preparations by considering activity coefficients and ion-pair corrections.
Effect of Indomethacin on the Blood Flow of the Rabbit Submandibular Gland
Authors: Fazekas A. , Posch E. , Zelles T.
Published: November 2010

Effects of the stimulation of the chorda tympani and acetylcholine infused into the artery of the gland were studied on the blood flow and saliva secretion of the rabbit submandibular gland before and after indomethacin treatment. The enhancement of blood flow and saliva secretion was less apparent after indomethacin than before. Results suggest that endogenous prostaglandins are also involved in the mechanism of the augmentation of blood flow and saliva secretion produced by the stimulation of the chorda tympani in the rabbit submandibular gland.
Effect of Dichloromethylene Diphosphonate on Fluoride Balance in Healthy Men
Authors: Maheshwari U.R. , Leybin L. , McDonald J.T. , Schneider V.S. , Newbrun E. , Hodge H.C.
Published: November 2010

Healthy men with a daily intake of 0.37 mg fluoride were given dichloromethylene diphosphonate (Cl 2MDP) or a placebo during a period of ambulation followed by bed rest. In both groups, serum ionic fluoride was unchanged, and fluoride balances were negative, but Cl2MDP significantly reduced loss of fluoride in the treated groups.
The Cement-forming Properties of Phytic Acid
Authors: Prosser H.J. , Brant P.J. , Scott R.P. , Wilson A.D.
Published: November 2010

The properties of aluminosilicate-phytic acid cements were investigated. They proved to be fast-setting and resistant to acid attack, with the ability to bond to enamel, but not to dentin.
The Effects of an Incisal Bite Plane on Rat Sublingual Glands
Authors: Hioki S. , Niwa K. , Kishimoto T. , Kawazoe T. , Yokota Y. , Abe K. , Dawes C.
Published: November 2010

Application of an incisal bite plane for as little as three d caused a significant increase in the size of the sublingual glands of rats, with some evidence of hyperplasia and hypertrophy of the acinar cells. The enlargement had few effeets on salivary secretion, and the gland changes were reversible.
The Development of a Novel Tooth-root Implant Material
Authors: El Basty M.A. , Kamel I.L.
Published: November 2010

Polyacrylic acid-alumina composites have been developed in this laboratory and were found to be biocompatible and resistant to biodegradation. These composites can be designed to apply a predetermined pressure on the bone interface which was found beneficial for stimulation of new bone formation and increased bone densification at the implant interface. Optimization of the physical and mechanical properties is presented, and a brief summary of the subcutaneous and oral implantation is reported.
Water Absorption and Water Solubility of Soft Lining Materials for Acrylic Dentures
Authors: Braden M. , Wright P.S.
Published: November 2010

Soft lining materials undergo two processes when immersed in water. Plasticizers and other soluble materials are leached into the water, and water is absorbed by the polymer. The balance between these two processes affects both the compliance and dimensional stability of the materials.
Structure of High-temperature Oxidation Zones of Gold Alloys for Metal-Porcelain Bonding Containing Small Amounts of In and Sn
Authors: Ohno H. , Kanzawa Y. , Kawashima I. , Shiokawa N.
Published: November 2010

Changes in the morphology of the oxidation zone and the quantities of oxide for gold alloys containing two base metals (In and Sn) were investigated by exposing alloys at 1000°C for one h in air. The contents of In and Sn were varied in the range of from 0-1.5 wt%.

In the range of from 1.5-0,35 wt% In (from 0-1.15 wt% Sn), In2 O3 was formed predominantly at the alloy surface. The electron probe x-ray micro-analyzer detected no uniform external oxidation zone. A mixture composed of In2O3 and SnO2 precipitated internally in the alloy matrix.

An external oxidation zone composed of SnO2 was formed on the alloys containing over 1.2 wt% Sn, and no internal oxidation zone was observed.
Increases in Fluoride, Calcium, and Phosphate in Dental Plaque Resulting from the Use of a Mineralizing Mouthrinse Containing Urea and Monofluorophosphate
Authors: Pearce E.I.F. , Schamschula R.G. , Cooper M.H.
Published: November 2010

A mouthrinse used ten times over a four-day period increased the concentration of acid-extractable fluoride in immature plaque by 320%, calcium by 190%, and phosphate by 97%. Corresponding increases in mature plaque were smaller, yet significant. Diffusion of the ions from plaque was restricted, and hence a prolonged caries-inhibitory effect can be expected.
Validity of Clinical Assessments Related to the Cemento-enamel Junction
Authors: Hug H.U. , Van 't Hof M.A. , Spanauf A.J. , Renggli H.H.
Published: November 2010

The distance measured from a constant reference to the subgingival cemento-enamel junction by four observers with two different probes in 11 patients was compared to independent precision measurements of the same distance performed during periodontal surgery. The findings question the validity of probe measurements with relation to the cemento-enamel junction.
Ultrastructural Characteristics of Progenitor Cell Populations in the Periodontal Ligament
Authors: Gould T.R.L.
Published: November 2010

Electron microscope radio-autography was used in an attempt to identify any relationship between the location and degree of differentiation of progenitor cells in the periodontal ligament (PDL). Ligament fibroblasts were classified on the basis of their nuclear/ cytoplasmic ratio and their distance to the closest blood vessel measured. It was determined that an undifferentiated paravascular progenitor cell population exists, and that the PDL also contains progenitor cells showing a range of cytodifferentiation.
Identification of a Cathepsin B-like Protease in the Crevicular Fluid of Gingivitis Patients
Authors: Eisenhauer D.A. , Hutchinson R. , Javed T. , McDonald J.K.
Published: November 2010

Crevicular fluid from gingivitis patients contains significant levels of a cysteine protease which was characterized as the lysosomal protease cathepsin B, as judged by substrate specificity, thiol dependence, pH optimum, kinetic parameters, pH stability, and inhibitor sensitivities. A highly-sensitive fluorometric assay procedure was used to establish the mean level of cathepsin B activity for 25 gingivitis patients.
Dentin Stresses in Post-reconstructed Teeth with Diminishing Bone Support
Authors: Reinhardt R.A. , Krejci R.F. , Pao Y.C. , Stannard J.G.
Published: November 2010

Dentin stresses from simulated functional loads to post-reinforced tooth models with four levels of periodontal support were calculated using finite element analysis. As bone levels diminished, stresses were found to increase dramatically and to concentrate in the small amount of dentin remaining near the post apex.
Effect of Mandibular Molar Anatomy on the Buccal Class I Cavity Preparation
Authors: Re G.J. , Pruitt D. , Childers J.M. , Norling B.K.
Published: November 2010

In mandibular molars, enamel dramatically increases in thickness at the buccal pit area and progresses occlusally due to an extensive concavity in the buccal dentinal core, In order to comply with the principles of operative dentistry, this anatomic variance dictates that, if the ultimate restoration is to be placed in dentin, the axial wall of a Class I buccal pit preparation should incline medially rather than follow the external contour of the tooth. The occlusal cavosurface angle of the preparation should be obtuse to coincide with enamel rod direction. Retention, when needed, should be placed at the mesio-axial and disto-axial line angles to avoid undermining occlusal intercuspal enamel, especially as the preparation approaches 2 mm occlusal to the buccal pit,
Enzymatic Sulfation of Glycosphingolipids in Rat Parotid Salivary Glands
Authors: Zdebska E. , Liau Y.H. , Slomiany A. , Slomiany B.L.
Published: November 2010

The results of this study demonstrate that sulfatoglycosphingolipids of rat parotid salivary glands consist of galactosylceramide and lactosylceramide sulfates. The enzyme activity which catalyzes the formation of these compounds in vitro via transfer of sulfate from 3'-phosphoadenosine-5'-phosphosulfate to galactosyl- and lactosylceramide is located in the microsomal fraction of parotid glands. This sulfotransferase exhibits its optimum activity at pH 6.8 and requires the presence of Triton X-100, Mg2 +, and F1-.
A Biochemical Study of Two Bifunctional Reagents as Alternatives to Formocresol
Authors: Ranly D.M. , Lazzari E.P.
Published: November 2010

Two bifunctional reagents, glutaraldehyde and dimethylsuberimidate, were compared to formaldehyde with respect to fixation and modification of protein. Glutaraldehyde proved the superior fixative based on cross-linking and enzyme degradation assays. An immunoprecipitation assay suggests that the reaction products of glutaraldehyde may have altered antigenicity.
Clinical Science
Authors: Jensen M.E. , Schachtele C.F.
Published: November 2010

Changes in plaque pH after a sucrose rinse were simultaneously monitored by plaque sampling, touching of the plaque with antimony and glass electrodes, and telemetry. The minimum pH at approximal sites was approximately 0. 7 pH units lower than that on buccal surfaces. The pH at the approximal site remained below resting levels after 120 min, and the area under the pH response curves from this site was five times greater than that from the buccal surfaces.
A Mouthrinse which Optimizes in vivo Generation of Hypothiocyanite
Authors: Mansson-Rahemtulla B. , Pruitt K.M. , Tenovuo J. , Le T.M.
Published: November 2010

We report here the properties of a mouthrinse which enhances one of the natural defense factors in human saliva, the salivary peroxidase system. Concentrations of the antimicrobial agent, the hypothiocyanite (OSCN-) ion, can be increased in vivo to bacteriostatic levels by use of a mouthrinse which is 4 mM (0.014%) in hydrogen peroxide and I mM (0.0097%) in potassium thiocyanate at pH 5.5. The volume of the rinse, the H2O2 concentrations, and the pH were shown to be determinants of the concentration of OSCN- generated by the rinse.
The Effect of Enamel De- and Remineralization on Permeability to Iodide and Urea
Authors: Amdur B.H. , Brudevold F. , Tehrani A.
Published: November 2010

Blocks of bovine enamel subjected to de- and remineralization were measured for changes in permeability to iodide and urea. Results were similar, indicating that the diffusion pathways for the two species were comparable, and that sites for iodide binding did not appear to exist.
Comparison of in vitro and in vivo Wear of Composites
Authors: Powers J.M. , Ryan M.D. , Hosking D.J. , Goldberg A.J.
Published: November 2010

In vitro wear data were determined for nine experimental composites and compared with two-year clinical data. The in vitro tests included single-pass wear and two-body abrasion. The in vivo data were obtained between 1978 and 1980 for 54 class 2 posterior composite restorations in 25 patients. Correlations between the in vitro and in vivo data were found with values of α less than 0.08.
Use of Bacteriophage-resistant Mutants to Study Actinomyces viscosus Cell Surface Receptors
Authors: Tylenda C.A. , Kolenbrander P.E. , Delisle A.L.
Published: November 2010

Spontaneously occurring bacteriophage-resistant mutants of Actinomyces viscosus were isolated. The mutants exhibited altered coaggregation patterns with streptococci. From analysis of the data, it appears that a cell surface structure on A. viscosus may function both as a phage receptor and as a binding site for co-aggregation with certain oral streptococci. These mutants will be valuable in the study of surface structures that mediate one type of the cell-to-cell interactions that occur between these two important groups of oral bacteria.
Fluoride Concentrations in Rat and Human Tooth Pulps and Their Possible Interference with Phosphatase Activities
Authors: Ericsson Y. , Angmar-Mansson B.
Published: November 2010

Alkaline and acid phosphatases (p-ases), fluoride (F), and calcium (Ca) were analyzed in the pulps of rat incisors and young human pre-molars. P-ase activities were about ten times higher in the rat than in the human pulps; in the latter, high p-ase activity appeared to be connected with rapid mineralization. Average total F was 3-4 ng/mg in both rat and human pulp, while Ca showed values several times higher, although greatly varying, in human than in rat pulps. Ionized F was two to three times higher in ultrafiltrates from rat and human pulps than in the blood plasma of the species; in the rat, the F content of the ultrafiltrates increased only three to four times when plasma F was experimentally elevated over 100 times. In vitro, rat pulp alk. p-ase activity was slightly inhibited only in the range above 100 mM NaF, while acid p-ase showed weak inhibition in the region from 0.15-0.25 mM and 40-60% inhibition in the range from 10-100 mM NaF. In vivo, no effect on pulp p-ases was found, even from sublethal NaF doses.
Morphology of Enamel Surfaces Treated with Topical Fluoride Agents: SEM Considerations
Authors: Nelson D.G.A. , Jongebloed W.L. , Arends J.
Published: November 2010

Three topical fluoride agents deposited surface coatings of different morphology and thickness on intact human enamel surfaces. The agents studied were an acidic silane fluoride lacquer, a neutral NaF lacquer, and an APF gel. Each agent reacted with the enamel surface differently, producing its own distinctive etching pattern. The smallest particles observed in the surface coatings were from 20 to 30 nm in diameter and appeared to have indistinct morphologies. They often agglomerated into spherical globules ranging from 1-3 μ m in diameter.