bluuebunny/crossref_metadata_2025 huggingface dataset:
Weddellite in Submandibular Gland Calculus
Authors: Yamamoto H. , Sakae T. , Takagi M. , Otake S. , Hirai G.
Published: November 2010

Scanning electron microscopy of a submandibular sialolith showed octahedral and dipyramidal crystals located at the surface layer of cortex. The crystal habits observed were consistent with those of a tetragonal crystal system. X-ray microcdiffraction revealed the presence of weddellite. The origin of weddellite within the calculus remains to be determined.
Materials Science
Authors: Hirasawa T. , Hirano S. , Hirabayashi S. , Harashima I. , Aizawa M.
Published: November 2010

A study of the expansion of restorative composite resins associated with water sorption was conducted. The results show that this expansion depends upon the mass of water absorbed by the composite restorative. Although polymerization shrinkage can be compensated by expansion due to water sorption, the length of time involved in achieving this compensation is approximately seven d.
On Creep Mechanisms in Amalgams
Authors: Herø H.
Published: November 2010

Creep mechanisms have been investigated in both conventional and non-γ2 amalgams. The back stress during steady-state creep was measured by the "stress-dip" technique, and pre-polished vertical surfaces of nearly cylindrical specimens were studied after creep. Indications of both superplastic flow and dislocation creep were observed.
Characterization and Modification of Electrochemical Properties of Teeth
Authors: Tung M.S. , Brown W.E.
Published: November 2010

Perm selectivity of teeth was studied by membrane potential measurements. The enamel was found to have a preferential affinity for calcium and hydrogen ions. Its permselectivity could be modified by anionic compounds, such as phytate and alginate; by cationic compounds, such as protamine, polyarginine, and poly lysine ; or by an alternating coating of the above compounds.
Action of Drugs on Liposomes with Varying Charges
Authors: Fujisawa S. , Kadoma Y. , Masuhara E.
Published: November 2010

The effects of 12 amphipathic compounds-such as aromatic and aliphatic carboxylic acids, amines, imines, nitrogen-substituted derivatives, and aldehydes-on multilamellar liposomes with varying charges were monitored in biological systems. The stabilization-lysis action of amphipathic compounds on liposomes was influenced by either the electrostatic repulsion or the attraction force between these compounds and liposomes.
Effects of Composite Restorations on the Periodontal Membrane in Monkeys
Authors: Nasjleti C.E. , Castelli W.A. , Caffesse R.G.
Published: November 2010

We evaluated the histopathological response of the periodontal membrane to intentionolly-replanted teeth carrying composite (experimental) and silver amalgam (control) restorations in the middle third of each root. The study revealed that the amalgam produced, in the periodontal tissues, an initial localized inflammation that subsided with the subsequent formation of a fibrous capsule. However, the periodontal membrane adjacent to the composite resin restorations demonstrated chronic inflammation. It was concluded that the composite evoked chronic inflammatory responses of the periodontal tissues in monkeys.
Experimental Ridge Augmentation With Porous Hydroxyapatite Implants
Authors: Piecuch J.F. , Topazian R.G. , Skoly S. , Wolfe S.
Published: November 2010

A new hydroxyapatite ceramic implant material for restoration of atrophic edentulous ridges was tested in a canine animal model The structure of this material is unique, in that it is produced from the skeleton of a coral, and in that it is penetrated by a uniform network of interconnected pores. Results indicate that bone penetrates its structure to a greater degree than had been observed with similar implants constructed of different materials. Implant insertion through a simple surgical technique involving minimal morbidity is a viable method of placement.
Clinical Science
Authors: Rubin C. , Krishnamurthy N. , Capilouto E. , Yi H.
Published: November 2010

A three-dimensional finite element model has been developed for the purpose of analyzing the stress distribution in a human mandibular right first molar. The model takes into account the non-symmetric geometry and loading, and the material inhomogeneities of the tooth. Comparisons with existing two-dimensional analyses are given.
Clinical Science
Authors: Cohen M.E. , Cecil J.C.
Published: November 2010

Analyses of variance under the assumptions of either independence or intraclass correlation among observations were carried out on theoretical dental research data. Data sets varied with respect to the magnitude of a between-subjects treatment effect and the variance of scores within subjects. When scores within subjects were positively correlated (i.e., the intraclass correlation coefficient was greater than zero), the independence model provided tests which were too likely to reject the null hypothesis. Dental researchers who analyze sites (e.g., teeth, pockets) as independent observations, without establishing the intraclass correlation to be near zero, run the risk of reporting results in terms of an improper statistical model
The Role of Oral Kinesthesia in the Determination of the Swallowing Threshold
Authors: Takahashi T. , Morimoto T. , Azuma S. , Kawamura Y.
Published: November 2010

The interdental dimension discrimination (IDD) ability and the swallowing threshold were evaluated at the sitting and supine positions. The difference in the magnitude of mis-estimation of IDD and that in the swallowing threshold between the two positions was significantly correlated. These results indicate some influence of the IDD in the determination of the swallowing threshold.
Biosynthesis of 17β-estradiol and Its Binding to Specific Receptors in Human Gingiva
Authors: Vittek J. , Gordon G.G. , Munnangi P.R. , Rappaport S.C. , Southren A.L.
Published: November 2010

An increased biosynthesis of 17β-estradiol was found by microsomes obtained from the inflamed human gingivae when compared to those from healthy and hyperplastic tissues. In contrast, binding of estradiol to cytoplasmic receptors was increased only in hyperplastic tissue and was independent of the amount of estradiol formed.
Biomechanical Stress Analysis of the Amalgam-Tooth Interface
Authors: Peters M.C.R.B. , Poort H.W.
Published: November 2010

An axisymmetric finite element model of a restored lower molar was used to examine the effect of interface parameter changes on the stresses within the restored tooth. The resulting principal and equivalent stresses and displacements were evaluated and plotted throughout the model. It was found that changes in amalgam-tooth interface parameters resulted in noticeable changes in the stress distribution.
Post-irradiation Polymerization of Visible Light-activated Composite Resin
Authors: Leung R.L. , Fan P.L. , Johnston W.M.
Published: November 2010

The rate of post-exposure polymerization and the effects of initial polymerization on the final polymerization of visible light-activated composite resin were studied. The extent of polymerization, as indicated by hardness values, was influenced by the exposure time to the photo-activating radiation and by the post-exposure time. The timing of testing is critical when studying the properties of visible light-activated composite resins.
Tarnishing of a Low-gold Dental Alloy in Different Structural States
Authors: Herø H. , Jørgensen R.B.
Published: November 2010

Tarnish testing of a low-gold alloy has been carried out in a solution of Na2S. Different structures were created by means of heat treatments. Substantial variations in tarnish and corrosion resistance and in types of attack were observed. Annealing to a single phase structure gave the best resistance, while subsequent age-hardening had a deteriorating effect.
Volume and Composition of Pilocarpine- and Isoproterenol-stimulated Submandibular Saliva of Early Postnatal Rats
Authors: Martinez J.R. , Camden J.
Published: November 2010

Submandibular saliva was collected from early postnatal rats by cannulation of the main excretory duct of individual glands after i.p. injections of pilocarpine (10 mg/kg body weight) or isoproterenol (10 mg/kg body weight). With this method of saliva collection, a secretory response to pilocarpine was observed at two wk of age. The average weight of 40 glands was 35.6 ± 1.6 mg, and the average volume of saliva secreted in 60 min was 32 ± 2.2 μl. By three wk of age, the gland had approximately doubled in size (average weight of 39 glands = 61.9 ± 3.1 mg), and the average total volume of saliva secreted in 60 min was more than three times larger (120.4 ± 10.5 μl) than that secreted by two-week-old rats. The relationship between electrolyte (Na+, K+, Ca++) and protein concentrations and rate of flow was similar to that observed in pilocarpine-stimulated adult saliva, and did not differ appreciably in the saliva of two-and three-week-old animals. A measurable secretory response to isoproterenol was observed at three wk of age when saliva was collected by duct cannulation. The average total volume of saliva secreted in 60 min was 48 ± 3.1 μl, and salivary Na+and K+concen trations, and their relationship to flow rate, were similar to those of isoproterenol-stimulated adult saliva. Saliva Ca++and protein concentrations were also generally similar to those of isoproterenol-stimulated adult saliva. Total protein output (in 60 min) was 2½ times greater in three-week-old rats with isoproterenol stimulation (compared to pilocarpine stimulation), but was significantly smaller than that of isoproterenol-stimulated adult glands. It is concluded that the submandibular gland of early postnatal rats is capable of secreting saliva in vivo following cholinergic and β-adrenergic stimulation, and that this ability corresponds with the appearance of the corresponding autonomic receptors, but precedes cytodifferentiation, Ductal transport of electrolytes is well-developed at this stage of postnatal development, but fluid and protein output is smaller than in adult glands and requires full morphological maturation of acinar cells.
A Comparative Study of Salivary Lysozyme in Caries-resistant and Caries-susceptible Adults
Authors: Stuchell R.N. , Mandel I.D.
Published: November 2010

Lysozyme concentration was quantitated immunochemically in parotid and submandibular-sublingual saliva of 46 caries-resistant and 17 caries-susceptible adults. There was essentially no difference between the two groups. The concentration of lysozyme was three times higher in the submandibular-sublingual than in the parotid secretion, and was significantly higher in unstimulated submandibular saliva than in secretions stimulated with 1, 2, or 4% citric acid. There were no significant differences in flow rate between caries-resistant and -susceptible subjects. Salivary lysozyme concentration is not a critical determinant of resistance or susceptibility to caries.
Tooth Wear Rates Among Contemporary Australian Aborigines
Authors: Molnar S. , McKee J.K. , Molnar I.M. , Przybeck T.R.
Published: November 2010

Most reports of Aboriginal tooth wear have been descriptive, and few have dealt with the question of wear rate. This study records cusp heights of dental casts taken from individuals during a growth study of Aboriginal children from ages six to 18. Their rates of wear were greater than those of Europeans, and the most rapid rate was recorded among Aboriginal males. These differences are due to the quantity of dietary abrasives.
Prednisolone Clearance: A Possible Determinant for Glucocorticoid Efficacy in Patients with Oral Vesiculo-erosive Diseases
Authors: Lozada F. , Frey F.J. , Benet L.Z.
Published: November 2010

The pharmacokinetics of prednisolone were determined in 12 patients with oral vesiculo-erosive diseases. The bioavailability of prednisone in these patients exhibited a low intersubject variability, while the metabolic clearance rate of total and of unbound prednisolone varied considerably from patient to patient.
A Study of Productivity and Participation at IADR and AADR Annual Meetings from 1970 to 1981
Authors: Lee M.M. , Gardiner J. , Federico J. , Lane P.L.
Published: November 2010

An analysis was conducted of the scientific research productivity and participation in the International Association for Dental Research and the American Association for Dental Research annual meetings between 1970 and 1981. The study was designed to describe the overall level of participation, most productive institutions by year, and percent change in total research productivity of participating institutions and countries from 1970 to 1981. The results indicate that a total of approximately 687 different institutions representing 49 countries participated during the 12-year period. The total number of presentations increased by 77%, while the total number of participating institutions increased by 63%. The top 20 most productive institutions in any given year accounted for between 38 and 51% of all research presented. Of these top 20 participating institutions, approximately 83% were universities. An analysis by year and most productive institutions from 1980 to 1981 is presented.
Effects of Androgens on the Activity of Steroid-metabolizing Enzymes in the Murine Submaxillary Gland
Authors: Katsukawa H. , Tanabe Y. , Funakoshi M.
Published: November 2010

Effects of androgens on the activity of androgen-metabolizing enzymes have been investigated in the murine submaxillary gland. 5α-reductase activity is androgen-dependent, and 17β-hydroxysteroid dehydrogenase activity is androgen-resistant. The level and androgen-responsiveness of 5α-reductase in the murine submaxillary gland are not imprinted during the neonatal period by testicular androgens. Circulating androgen may have a cumulative effect on androgen response of 5α-reductase.
Mechanism of Action of an Antiseptic, Anti-odor Mouthwash
Authors: Pitts G. , Brogdon C. , Hu L. , Masurat T. , Pianotti R. , Schumann P.
Published: November 2010

Inter-related determinants of oral malodor were measured over a three-hour period in 30 human subjects after mouthwash treatments. Re-odoration was important to mouthwash activity for 30 min. At post-treatment times of 60-180 min, the anti-odor activity of the product is due solely to its anti-microbial action.
Blood Flow Changes in the Rabbit Maxilla Following an Anterior Osteotomy
Authors: Indresano A.T. , Lundell M.I.
Published: November 2010

This investigation considered circulatory changes in the distal segment of an anterior maxillary osteotomy produced in nine rabbits. Blood flow in the distal pulp, alveolar bone, and mucosa was measured using hydrogen washout. The results showed a decrease in blood flow in all tissues with a mucosal rebound within 30 min.
Materials Science A Simulation Model for Transient Thermal Analysis of Restored Teeth
Authors: De Vree J.H.P. , Spierings Th.A.M. , Plasschaert A.J.M.
Published: November 2010

A theoretical model was developed to analyze the influence of various cement bases on temperature distribution and heat flow in restored teeth. A physical model of a molar was developed to simulate different thermal processes by simple parameter variation. The time-dependent temperature field was calculated using the finite element method (FEM). The values for material properties and thermal load were chosen from the dental literature. The results are in good agreement with clinical experimental research as published by Trowbridge et al. 1 It is concluded that the model is a valid tool for further research with regard to the influence of restorative materials and cavity design on the thermal behavior of restored teeth.
Stress Analysis of a Tooth Restored with a Post and Core
Authors: Peters M.C.R.B. , Poort H.W. , Farah J.W. , Craig R.G.
Published: November 2010

An idealized axisymmetric finite element model of a second premolar restored with a post and core was used to study the distribution and magnitude of stresses as a function of the following parameters : the diameter of the post, the length and the shape of the post, and finally the interface characteristics between post and cement. Emphasis was directed toward the cement layer interposed between the post and the tooth. Bonding between the post and the cement appeared to be the most important parameter to achieve optimal mechanical behavior of the tooth-prosthesis combination.
Basic Biological Sciences
Authors: Hicks M.J. , Silverstone L.M.
Published: November 2010

The effect of acid-etching on SnF2-treated caries-like lesions was investigated. The results suggested that remineralization occurred, limited to the superficial portions of the lesions. In addition, we observed etching patterns which are comparable to those described for etched sound enamel.
The Extent of the Odontoblast Process in Normal and Carious Human Dentin
Authors: Yamada T. , Nakamura K. , Iwaku M. , Fusayama T.
Published: November 2010

When observed by SEM, after being treated with the HCl-collagenase method, the odontoblast processes extended throughout the whole thickness of dentin in intact teeth and the whole thickness of normal and the inner carious dentin in carious teeth. Small holes and depressions were found on the processes in the transparent layer.
Shallow Fluorine Depth Profiles of Cementum in Periodontal Disease—A Pilot Study
Authors: Crawford A.W. , Sampson W.J. , De Bruin H.J.
Published: November 2010

A nuclear resonant reaction depth profiling technique was used to analyze elemental fluorine distribution in the first 20 μ m of human dental cementum. A pilot sample of six periodontally-involved teeth indicated greater levels of fluorine in exposed cementum (0.9→2.4%) compared to cementum apical to the zone of epithelial attachment (0.4→1.1%). Furthermore, the exposed cementum appeared to have fluorine levels within the surface 5 μ m comparable to the hyper-mineralized layer previously reported by x-ray diffraction and microprobe techniques. The nuclear resonant reaction is a nondestructive technique which yields useful information of surface elemental distribution as a function of depth, and may be regarded as a potential means of analyzing changes in the inorganic constitution of cementum during various physico-chemical pre-treatments.
Clinical Science
Authors: Kinirons M.J.
Published: November 2010

The mean pH and buffering capacity of stimulated saliva collected from young cystic fibrosis patients were measured and were found to be significantly higher than were the values for the controls (p < 0.01). In addition, the caries experience of the cystic fibrosis children would appear to be considerably less than that of the controls. The association of these salivary alterations with a decreased caries experience is discussed.
Measurement of the Ability to Control Jaw Muscle Forces in Man
Authors: Lewis G.R. , Yemm R.
Published: November 2010

Subjects were asked to track a moving waveform on an oscilloscope screen, with the output of a force transducer placed between the teeth. It was found that, after a learning period, the error depended upon the clenching force, and that, over the force range studied, the greater the effort demanded, the greater the error.
Materials Science
Authors: Averette D.F. , Marek M.
Published: November 2010

In vitro corrosion of two low-copper and three high-copper deratal amalgams was examined using stressed and unstressed specimens. Stress was applied in tension; anodic polarization curves and polarization resistance were determined. In stressed condition, the passive current density was higher, and polarizatfon resistance was lower. The changes are attributed mainly to the fracture of passive films by creep strain.
The Relationship Between Filler Loading and Particle Size Distribution in Composite Resin Technology
Authors: Cross M. , Douglas W.H. , Fields R.P.
Published: November 2010

Distinct composite structures are characterized by the ratio of liquid resin volume to non-filler volume of the material constituting the filler. If the ratio is less than one, there is high particle-to-particle interaction. If the ratio is greater than one, particles are pushed apart, and the burden of energy dissipation falls upon the resin.
Effect of Xylitol on the Growth and Glycolysis of Acidogenic Oral Bacteria
Authors: Vadeboncoeur C. , Trahan L. , Mouton C. , Mayrand D.
Published: November 2010

We investigated the effect of xylitol on the growth of different oral bacteria in the presence of glucose. Xylitol inhibited the growth of all but one of ten strains of S. mutans and failed to inhibit the growth of the lactobacilli, actinomycetes, and other streptococci tested except S. sanguis 10556, which was slightly inhibited. However, the rate of acid production of the sensitive S. mutans strains was not equally affected by xylitol. These data, obtained with pure cultures of acidogenic oral bacteria, may explain the lack of an in vitro inhibitory effect of xylitol on dental plaque samples.
The Acidogenic Potential of Reference Foods and Snacks at Interproximal Sites in the Human Dentition
Authors: Jensen M.E. , Schachtele C.F.
Published: November 2010

Telemetry was used to evaluate changes in plaque pH at interproximal sites in the dentition of five human subjects following the ingestion of a variety of reference foods and snacks. Short-term telemetry (30 min) revealed that most of the substrates yielded both pH minima and total responses similar to that obtained with a 10% sucrose rinse. Aged Cheddar cheese and skim milk were much less acidogenic than were the other foods.
Rat Caries Assay of Reference Foods and Sugar-containing Snacks
Authors: Navia J.M. , Lopez H.
Published: November 2010

Using standard reference snack foods, we tested a method, using rats fed in a programed feeding machine, to evaluate the caries-promoting properties of foods. Results, which were expressed in relation to a control food, indicate that the method distinguished differences in caries potential among a number of different snack foods. Buccal and sulcal caries scores of rats fed snack foods varied in their responses. A gel diet used to provide essential nutrients for the rat growth in this approach contributed minimally to the caries response which was related principally to the food being tested.
Storage of Experimentally Avulsed Teeth in Milk Prior to Replantation
Authors: Blomlöf L. , Lindskog S. , Andersson L. , Hedström K.-G. , Hammarström L.
Published: November 2010

Extracted monkey teeth were endodontically treated, stored in milk or saliva for two or six h, and then replanted. Periodontal conditions were evaluated after eight wk. Teeth that had been stored for two or six h in milk or for two h in saliva showed periodontal healing almost as good as that of immediately replanted teeth. Teeth that had been kept in saliva for six h or bench-dried for one h showed extensive replacement resorption. Milk may thus be recommended as a storage medium for ex-articulated teeth prior to replantation in cases when immediate replantation is not possible.
Phase Variation of Hyaluronidase-producing Peptostreptococci Associated with Periodontal Disease
Authors: Tam Y.-C. , Chan E.C.S.
Published: November 2010

Peptostreptococci isolated from diseased periodontal pockets produced large amounts of extracellular hyaluronidase throughout their growth cycle. Phase variants, obtained by re-streaking aged colonies of the wild types, had different colonial morphology and shorter generation times. These variants produced less hyaluronidase, and enzyme production occurred only during the early stationary phase.
Comparative Growth Responses of Oral Streptococci on Mixed Saliva or the Separate Submandibular and Parotid Secretions from Caries-active and Caries-free Individuals
Authors: Cowman R.A. , Baron S.S. , Fitzgerald R.J. , Stuchell R.E. , Mandel I.D.
Published: November 2010

Growth of S. mutans on mixed or parotid saliva from CF individuals may be influenced by the availability of growth-supportive proteins or the inhibitory activity present in parotid saliva. A deficiency in growth-supportive proteins may explain the limited growth of S. sanguis on mixed or submandibular saliva from these individuals.
The Effects of Parathyroid Hormone, Calcitonin, and Vitamin D Metabolites on Calcium Transport in the Secretory Rat Enamel Organ
Authors: Bawden J.W. , Deaton T.G. , Crenshaw M.A.
Published: November 2010

The effects of parathyroid hormone (PTH), calcitonin (CT), 1,25(OH)2D3, and 24,25(OH) 2D3 on calcium transport through the secretory stage enamel organ were studied on developing rat molars in vitro. 24,25(OH)2D 3 increased 45Ca uptake by the explants. 24,25(OH)2 D3 plus PTH further enhanced 45Ca uptake and resulted in an increase in net calcium uptake by the developing enamel.
Concentration Changes in Surface Ca, P, F, Zn, Fe, and Sr During White Spot Formation
Authors: Crawford A.W. , De Bruin H.J.
Published: November 2010

The purpose of this study was to investigate the mechanism of surface layer formation in artificial white spots. Two nondestructive nuclear micro-analysis techniques were employed to analyze windows of human dental enamel at progressive stages of an artificial lesion. Fluoride concentrations were measured to a depth of 9 μm using resonant reaction profiling. Surface concentrations of Ca, P, Zn, Fe, and Sr were measured using proton-induced X-ray emission. The enamel windows were analyzed longitudinally after zero, four, and 16 hours' exposure to lactic acid gels of pH 3.7 and pH 4.5. During the first four hr of lesion formation, non-fluoridated apatite was preferentially removed from the surface with up to a 40% loss of Ca and P, depending on the gel pH. The next 12 hr saw a build-up of Ca and P in the surface to values approaching those of healthy enamel. In comparison, F and Sr concentrations changed very little, Fe tended to show a small increase at the end of each demineralization period, and Zn was less readily lost and gained than was Ca. These results and others suggest that the white spot surface layer phenomenon is a combined demineralization/remineralization process aided by, but not requiring, the presence of endogenous fluoride.
Dental Caries and Strontium Concentration in Drinking Water and Surface Enamel
Authors: Athanassouli T.M. , Papastathopoulos D.S. , Apostolopoulos A.X.
Published: November 2010

We investigated the possible cariostatic effect of strontium in the absence of effective amounts of fluoride by relating the DMFT index of the population to the strontium and fluoride concentrations in drinking water and enamel surfaces. The epidemiological survey was conducted in two neighboring districts in the northwest part of Greece, involving 582 children ranging in age from 11 to 14. The average DMFT values were 5.26 in the high-strontium (2.9-7 ppm Sr) area and 6.95 in the low-strontium (0.2-1.3 ppm Sr) area, while fluoride was low (< 0.06 ppm) in both districts. Further, the average strontium concentration in surface enamel was higher in the high-strontium area.
Basic Biological Sciences
Authors: Takai N. , Yoshida Y. , Kakudo Y.
Published: November 2010

Glucose permeation from blood to saliva appeared to follow the para cellular pathway in rat submandibular and sublingual glands, and the permeability was much higher in the sublingual than in the submandibular gland. The duct system re-absorbed glucose in the submandibular but not the sublingual gland. The glucose concentration in sublingual saliva was inversely related to the flow rate.
Acid Reactivity of Carbonated Apatites with Strontium and Fluoride Substitutions
Authors: Featherstone J.D.B. , Shields C.P. , Khademazad B. , Oldershaw M.D.
Published: November 2010

Carbonated apatites containing approximately 3.0 or 6.5% CO3 were precipitated in the presence of sodium, strontium, and/or fluoride at various concentrations. Almost all the available strontium and fluoride was incorporated into the crystals, whereas only a portion of the carbonate and sodium present was taken up. When incorporated together, Sr and F improved the crystallinity of carbonated apatites and markedly reduced their acid reactivity. This phenomenon may partially explain the observed reduction in caries for populations whose drinking water contains optimum levels of Sr at 5-10 mg/l and Fat 1-2 mg/l.
A Statistical Analysis of the Clinical Response to the Single-crystal Sapphire Endosseous Dental Implant in Dog Jaws
Authors: Steflik D.E. , McKinney R.V. , Koth D.L.
Published: November 2010

A statistical analysis was carried out an the clinical evaluatory data gathered from a two-year longitudinal study of the single-crystal sapphire endosteal dental implant in dog jaws. Statistically, the implants behaved either better than control molars (clinically), or in a manner similar to control molars. These data suggest an excellent prognosis for the single-crystal sapphire dental implant.
Effects of Fatigue on a Soldered Base Metal Alloyt
Authors: Hawbolt E.B. , MacEntee M.I.
Published: November 2010

An in vitio tensile fatigue test produced cyclic loading of joints made in a base metal casting alloy with a low-temperature precious metal solder, and the number of cycles to failure was recorded for a range of cyclic stresses. The majority of the joints survived stresses that should represent normal intra-oral loading.
The Effect of Some Metal Ions on the Intradental Sensory Nerves of the Cat
Authors: Panopoulos P. , Palaghias G. , Olgart L.
Published: November 2010

Intradental nerve activity from canine teeth of anesthetized cats was recorded during the application of different metal ion solutions in a dentinal cavity. The application of Ag2+, Ca2+, Cd2+, Cr3+, Hg 2+, Mg2+, Mn2+, Ni2+, Pb2+, Pd2+, Sn2+, and Zn2+ reduced the nerve activity induced by NaCl 0.76 M and compound 48/80. The application of Cu2+ and Co2+ excited the intradental sensory nerves.
A Comparison of Tooth Eruption Patterns Between Two Colonies of Young Marmosets (Callithrix jacchus)
Authors: Goss A.N.
Published: November 2010

The tooth eruption patterns of two large groups of young living marmosets were compared. The eruption sequence was essentially similar and was consistent with previous studies based on smaller numbers of dead animals. At nine mo, however, one group was more advanced than the other, although their craniofacial growth patterns were similar.
Clinical Science The Effect of an Antibacterial Solution on the Microflora of Human Incipient Fissure Caries
Authors: Meiers J.C. , Schachtele C.F.
Published: November 2010

A technique for collecting various levels of plaque from incipient occlusal fissure caries was used to evaluate the antibacterial properties of a solution containing I2-KI, CuSO4, and ethanol. In comparison with control fissures (n = 6), the treated fissures (n = 9) showed a 98% difference in recoverable bacteria, with the killing of S. mutans, Actinomyces, and lactobacilli appearing to reflect the level of agent penetration.
Sexual Dimorphism in the Emergence of the Deciduous Teeth
Authors: Tanguay R. , Demirjian A. , Thibault H.W.
Published: November 2010

Exact ages of emergence of the twenty deciduous teeth have been investigated on a longitudinal sample of 195 French-Canadian children (113 boys and 82 girls). A multivariate analysis of variance yielded a significant overall sex difference (p<O. 0001).

It has been found that the emergence of the deciduous dentition in boys is more precocious than that in girls by about one month; this difference is present at the emergence of the upper central incisor and is maintained henceforth. The only notable exception to this pattern is the emergence of the first molars.

Results of the present study, combined with those of previous research, suggest that sexual dimorphism in the emergence of the deciduous teeth could be mediated through ethnic factors.
The Effect of Dental Amalgam Restorations on Blood Mercury Levels
Authors: Abraham J.E. , Svare C.W. , Frank C.W.
Published: November 2010

Mercury levels in blood and in mouth air before and after chewing were measured in 47 persons with ana 14 persons without dental amalgam restorations. Questionnaires relating to exogenous sources of mercury exposure were administered to both groups. Differences in the mouth air mercury levels before and after chewing were statistically significant in the group with amalgams, but not in the group without amalgams. Analysis of the data from the questionnaires indicated that little or no exogenous exposure to mercury occurred among the two groups. Blood mercury concentrations were positively correlated with the number and surface area of amalgam restorations and were significantly lower in the group without dental amalgams.
Neuraminidase Activity: A Biochemical Marker to Distinguish Streptococcus mitis from Streptococcus sanguis
Authors: Murray P.A. , Levine M.J. , Tabak L.A. , Reddy M.S.
Published: November 2010

Selected reference and freshly isolated strains of Streptococcus mitis (mitior) and Streptococcus sanguis were assayed for cell-associated neuraminidase activity by their ability to hydrolyze [3H-] sialyllactitol. A cell-associated neuraminidase was detected with S. mitis and S. sanguis serotype II ( reclassified as S. mitis) but not with S. sanguis serotypes I and III. Neuraminidase activity of S. mitis correlated with this organism's inability to hydrolyze arginine, aesculin, and few, if any, sugars. The findings indicate that the presence of cell-associated neuraminidase activity is useful for the taxonomic classification of S. mitis.
Relaxation of Polymerization Contraction Stresses by Flow in Dental Composites
Authors: Davidson C.L. , De Gee A.J.
Published: November 2010

The hardening stresses in wall-to-wall bonded composites were measured and related to calculated values obtained from freely shrinking materials. Since the ultimate tensile strength of the materials contracting under restricted conditions was not lower than that of composites which were not hindered during the polymerization shrinkage, the conclusion was drawn that the contraction was compensated for by flow instead of internal disruptions.
Rat Intestinal Vitamin D-dependent Calcium-binding Protein: Immunocytochemical Localization in Incisor Ameloblasts
Authors: Taylor A.N. , Gleason W.A. , Lankford G.L.
Published: November 2010

Antiserum raised against the 10,000-Dalton vitamin D-dependent calcium-binding protein (CaBP10 ) from rat intestine was used to localize CaBP10 immunocytochemically in histological sections of rat mandible using an indirect immunoperoxidase method. Ameloblasts in the zone of maturation, along the continuously erupting incisor, contained CaBP10 throughout their cytoplasm. It was present in both smooth-ended ameloblasts and ruffle-ended ameloblasts. CaBP10 was not found in earlier developmental stages of ameloblasts or in other cells involved in tooth formation, i.e., odontoblasts, pulpal cells, cells of the stellate reticulum, papillary layer, and outer dental epithelium. The presence of CaBP10 in ameloblasts suggests that the vitamin D-endocrine system may have a direct effect on tooth formation in addition to the indirect effect of maintaining the required levels of serum calcium and phosphorus required for mineralization.
Activity of Streptococcus mutans a-D-Glucosyltransferases Released Under Various Growth Conditions
Authors: Walker G.J. , Brown R.A. , Taylor C.
Published: November 2010

The effect of a variety of growth conditions on extracellular D-glucosyltransferase (GTF) activity of Streptococcus mutans strains in continuous culture has been studied. Maximum GTF activity was found at low growth rates and at pH 6.5, and under this condition the predominant glucosyltransferase was GTF-S, an enzyme that synthesized soluble dextran. At high growth rates, the proportion of GTF-S decreased, and 50% or more of the total glucosyltransferase was GTF-I, an enzyme that synthesized water-insoluble (1→3)-α-D-glucan. Variation in the relative activities of GTF-S and GTF-I results in such diversity in the glucans synthesized from sucrose that it is virtually meaningless to describe a structural analysis of S. mutans glucan without specifying the conditions of growth of the organism.
Virulence Factors of Streptococcus mutans and Dental Caries Prevention
Authors: Hamada S. , Koga T. , Ooshima T.
Published: November 2010

Streptococcus mutans possesses the abilities to adhere to pellicle-coated tooth surfaces and to form acids - two characteristics associated with the cariogenicity of this micro-organism. De novo synthesis of insoluble glucan by S. mutans glucosyltransferase from sucrose is essential in the adherence process. Therefore, agents which interfere with the adherence ability of S. mutans would be useful for controlling dental caries. In the present report, we have summarized our recent findings concerning virulence factors of S. mutans and means for prevention of S. mutans- induced dental caries.
Induction and Delivery of Mucosal Immune Responses
Authors: Husband A.J. , Dunkley M.L. , Scicchitano R. , Sheldrake R.F.
Published: November 2010

The oral cavity is relatively deficient in lymphoid tissue capable of directing the inductive and effector events required for effective mucosal IgA responses to local antigen. Recent evidence regarding a common mucosal immune system has raised new possibilities in immunization of mucosal surfaces. This review describes the role of the intestine in contributing to responses at distant mucosal sites and in particular emphasizes the immune potential of the intestine in determining the success of immunization strategies to control dental caries.
The Volume of Saliva in the Mouth Before and After Swallowing
Authors: Lagerlof F. , Dawes C.
Published: November 2010

In 20 male and 20 female adult subjects, the volume of saliva in the mouth before (VMAX) and after (RESID) swallowing was determined. RESID could be computed by measuring the potassium and chloride concentrations in unstimulated saliva and in the expectorate after a five-second rinse with 5 ml of water immediately following a swallow. The mean value of RESID after a normal swallow was significantly higher in males (0.87 ml) than in females (0.66 ml). After a forced swallow, RESID was only slightly but significantly reduced, being 0.82 ml and 0.60 ml in males and females, respectively. The volume of saliva normally swallowed was calculated from the unstimulated salivary flow rate and the normal swallowing frequency. The mean value of VMAX (RESID plus volume normally swallowed) in males was 1.19 ml, which was slightly but not significantly higher than that in females (0.96 ml). When water was infused into the mouth at increasing flow rates, there was an increase in VMAX and in both the volume of fluid swallowed and the swallowing frequency.
Single Bovine Enamel Particles Examined by Electron Optics
Authors: Landis W.J. , Navarro M. , Neuringer J.R. , Kurz K.
Published: November 2010

Whole enamel scrapings from teeth of embryonic calves have been separated by density gradient centrifugation in organic solvents into fractions (1.6 < p < 2.4 g/cm3) representing progressive stages of mineral phase maturation. Single enamel particles or their small aggregates from such fractions were examined by transmission electron microscopy, electron diffraction, and high-spatial-resolution electron probe micro-analysis. The electron optical methods demonstrated the presence of poorly crystalline hydroxyapatite as the only detectable solid phase in all fractions. Octacalcium phosphate and brushite were not identified in the fractions. Changes in electron diffraction patterns were indicative of a progressive increase in apatite crystallinity with enamel maturation. Molar Ca/P ratios were found to range from 1.48 to 1.70, with a higher mean value obtained for lower-density fractions (p < 2.0 g/cm3). Lower-density fractions contained some particles with high ratios (~2.0-4.0) and a non-uniform distribution of Ca and P, as revealed by electron probe mapping. These characteristics are suggested as possibly being related to carbonate phases in early enamel.
The Effect of Topical Fluoride Applications on the Surface Free Energy of Human Enamel- An in vitro Study
Authors: De Jong H.P. , Van Pelt A.W.J. , Busscher H.J. , Arends J.
Published: November 2010

The surface free energy γ s and its polar and dispersion components γsp and γsd were determined from contact angle measurements on human enamel treated with sodium fluoride, acidulated phosphate fluoride (APF), and aminfluoride solutions. Sodium fluoride solutions only slightly influenced the surface free energy component γsp. The γsp value of the APF-treated human enamel increased from 52 to 66 erg.cm-2. The γsp value after aminfluoride treatment decreased from 52 to 19 erg.cm-2. The γsd values remained about 35 erg.cm-2 for all specimens measured. It is suggested that aminfluoride-treated enamel surfaces may exhibit a reduced tendency for bacterial adhesion.
Wound Healing Following Dental Extractions in Rabbits: Effects of Tranexamic Acid, Warfarin Anti-coagulation, and Socket Packing
Authors: Vinckier F. , Vermylen J.
Published: November 2010

We have investigated the importance of the coagulation and fibrinolytic systems for wound healing following dental extractions. Four front teeth were extracted in rabbits; wound healing was measured as time until complete epithelial closure. The antifibrinolytic agent tranexamic acid shortened duration of waund healing in normal rabbits. Anti-coagulation with warfarin delayed epithelial closure, which was, however, normalized by simultaneous administration of tranexamic acid, whereas complete packing of the soeket with oxidized cellulose had no corrective effect. Apical packing together with tranexamic acid gave normal healing. It is concluded that the quality of the fibrin network within the dental socket determines the rate of wound healing; oxidized cellulose is not an adequate substitute for fibrin.
Tooth Ultrastructure of Late Triassic Haramiyidae
Authors: Frank R.M. , Sigogneau-Russell D. , Voegel J.C.
Published: November 2010

Six molars of Haramiyidae from the French lower Rhaetic were examined by scanning and transmission electron microscopy, and by electron diffraction. Typical polished wear facets were located on the tops and on the occlusal bases of cuspids. Enamel was found to have had a structural pattern defined as "pre-prismatic", consisting of a repetitive pinnate orientation of the c-axes of apatite crystallites but without interprismatic material. Peritubular dentin was not found, but hydroxyapatite deposition in the dentinal tubular lumens was observed, whereas typical denticles with dentinal tubules and hydroxyapatite deposits were located in the pulp chambers. Taken together, these different features are strongly indicative of mastication, and hence enforce the suspected mammalian status of the Haramiyidae.
Augmentation of Tooth and Jaw Regeneration in the Frog with a Digital Transplant
Authors: Howes R.I. , Bakers E.C.
Published: November 2010

Augmentation of a regeneration site in the maxilla of the frog with a digital transplant resulted in an earlier bony union but did not affect the rate of regeneration of teeth which still ankylosed to a separately indueed bany base rather than to the transplanted digital bone.
Materials Science Subsurface Damage Layer of in vivo Worn Dental Composite Restorations
Authors: Wu W. , Toth E.E. , Moffa J.F. , Ellison J.A.
Published: November 2010

Dental composite restorations have been examined using a silver staining method to elucidate in vivo wear mechanisms. Emphasis was placed on examination of material immediately beneath the wearing surfaces. Several in vitro tests were also investigated for their ability to generate in vivo- like surface defects. For all the clinically worn composite restorations, a porous layer has been observed beneath those surfaces exposed to the oral environment. A laboratory test using certain substances to simulate the oral environmental effects can reproduce this porous layer. These results suggest that the in vivo wear process of dental composites is one accelerated by environmental softening of the composites.
Prevention of in vitro Secondary Caries with an Experimental Fluoride-exchanging Restorative Resin
Authors: Zimmerman B.F. , Rawls H.R. , Querens A.E.
Published: November 2010

We investigated the development of artificial caries lesions adjacent to experimental composite resins which release fluoride by ion exchange. Overall, compared with both a commercial, non-fluoride composite and a restorative silicate cement, the cavity walls and tooth surfaces immediately adjacent to the experimental resins developed fewer and/or smaller lesions. When lesions did develop, they did not penetrate as far along the cavity walls adjacent to the experimental materials. In general, the degree of protection imparted by the fluoride composites increased with increasing fluoride content. These results demonstrate the potential of these adhesive resins for restorative and other dental applications in which an extended fluoride presence would be of benefit.
Development of New Agents and Techniques for Intravenous Analgesia
Authors: Thut P.D.
Published: November 2010

The search for new anesthetic and analgesic drugs will be aided by analysis of the structures of chemical compounds which variously stimulate the five proposed opioid receptors or the benzodiazepine receptors. The mechanism of interaction between the benzodiazepines, opioids, and the neuroleptics will be further elucidated. These studies will result in discovery of drugs with fewer side-effects and more specific clinical effects.
Differential Pharmacology of Drugs Used for Intravenous Pre-medication
Authors: Dionne R.A.
Published: November 2010

The differential effects of drugs used for intravenous pre-medication are reviewed using the results of controlled clinical trials in dental outpatients. The evaluation of clinical success requires experimental control of factors which can confound both the therapeutic and evaluation processes. The evaluation of drugs which are given primarily to alleviate anxiety requires that this effect be assessed by the patient's self-report rather than by the clinician's estimate of drug effect based on external manifestations. The results of the studies reviewed suggest that intravenous diazepam accomplishes the therapeutic objectives of anxiety relief, decreased pain perception, and amnesia. The addition of a narcotic, while reducing the diazepam dose, does not result in any greater effect, but does improve patient cooperation. It is concluded that diazepam, administered to clinical end-point, accomplishes most of the goals of intravenous pre-medication with minimal potential for adverse effects. The use of additional agents may improve patient cooperation, but this possible advantage must be weighed against the potential for increased systemic effects.