bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorporation of Fluoride by Human Enamel: III. In Vivo Effects of Nonfluoride and Fluoride Prophylactic Pastes and APF Gels
Authors: Stearns Robert I.
Published: November 2010

Prophylactic procedures with a nonfluoride paste decrease the enamel surface fluoride concentration, whereas a sodium fluoride paste tends to prevent this loss. Topical acidulated phosphate-fluoride gel treatments exceed the equilibrium of enamel fluoride concentrations that are obtained subsequently by a second-order fluoride loss reaction.
The Failure of Aging or Loss of Teeth to Drastically Alter Mandibular Angle Morphology
Authors: Israel Harry
Published: November 2010

This investigation does not support the hypothesis that the angle of the jaw becomes more obtuse with age and loss of dentition. A sample of women was studied radiogrammetrically in a cross-sectional and longitudinal manner. It was demonstrated that the mandibular angle maintains a stable configuration from adulthood to old age regardless of dental status.
Petrographic Study of the Refractory Performance of High-Fusing Dental Alloy Investments: I. High-Fired, Phosphate-Bonded Investments
Authors: Mabie Curtis P.
Published: November 2010

Detailed X-ray, optical microscopic, optical emission, and electron probe analyses of a phosphate-bonded investment before and after firing and after casting were made. Complex sintering reactions that involve incipient liquefaction generate bonds in the fired investment. The refractory behavior of this investment, which is reflected by the extent of liquefaction induced by casting, may influence casting roughness, fit, and porosity.
Effect of Retainer Margin and Distribution of Mercury on Dental Amalgam Mercury Vaporization Patterns
Authors: Svare Carl W. , Hunt Ronald J. , Kai Chiu Chan
Published: November 2010

The results of this study showed that mercury vaporization patterns were not related directly to specimen postset mercury distribution. During the setting process, amalgam specimen retainer configurations affected these patterns significantly.
Age Changes in the Occlusal Pattern of Deciduous Dentition
Authors: Nanda Ram S. , Khan Inamullah , Anand Reena
Published: November 2010

The occlusal patterns of 2,500 children, 2 to 6 years of age, were examined. A straight, terminal plane relationship predominated at all ages. The termination patterns seemed to change with age, and this was caused by mesial migration of the mandibular arch and by mesial mandibular shift.
Heat Transfer in Teeth
Authors: Jacobs H.R. , Thompson R.E. , Brown W.S.
Published: November 2010

Experiments were conducted to determine the thermal resistance between food and teeth during mastication processes and the drinking of beverages. It was found that the assumption of negligible resistance between food and teeth overestimates greatly the resulting temperature gradients. Also, heat transfer coefficients (reciprocal thermal resistance) during drinking and mastication are below 7.0 X 10 -2 calorie/cm2 second°C.
Zinc Oxide-Eugenol Cements: IV. Microstructure and Hydrolysis
Authors: Wilson Alan D. , Clinton Desmond J. , Miller Robert P.
Published: November 2010

The microstructure of zinc oxide-eugenol cement and the water-leached product was examined by electron microscopy and scanning electron microscopy. Crystalline zinc eugenolate, which forms a reaction product, encases and binds unconsumed zinc oxide grains. Water leaching removes zinc eugenolate and leaves a voided structure bound by zinc hydroxide, which readily disintegrates.
SnHPO 4 from the Reaction of Stannous Fluoride and Hydroxyapatite at a Low pH
Authors: Nelson K.G. , Bainbridge C.A.
Published: November 2010

The reaction of stannous fluoride with hydroxyapatite at pH values less than 2 was studied. The X-ray diffraction powder pattern indicates that the major product is SnHPO 4. Chemical analysis corroborated this finding and also indicated a minor amount of calcium and fluoride. SnHP04 was synthesized and its X-ray pattern was compared with the reaction product.
Epidemiologic Study of Dental Caries Experience and Between-Meal Eating Patterns
Authors: Bagramian R.A. , Russell A.L.
Published: November 2010

The relationship between dental caries and between-meal snacks was investigated in a study of 1,486 high school students. The participants completed a questionnaire on between-meal habits and then were given dental examinations. The lack of differences in dental caries between racial and geographic groups was not related to the frequency of sucrose-containing, between-meal snacks.
Alveolar Ridge Augmentation with Ceramics
Authors: Hammer Wade B. , Topazian Richard G. , Mc Kinney Ralph V. , Hulbert Samuel F.
Published: November 2010

Porous calcium aluminate ceramic segments implanted for augmentation of deficient residual mandibular ridges proved clinically, radiologically, and histologically compatible with oral soft and hard tissues after a one year follow-up study.
Interrelationships and Sex Differences of Dental and Skeletal Measurements
Authors: Anderson Donald L. , Thompson Gordon W.
Published: November 2010

Mandibular canine width and eruption age permit as high a degree of sex discrimination as do skeletal dimensions. Hence, canine width could be useful for sex determinations in forensic dentistry. Canine width and eruption age were not related, but in males both were related to the amount of canine separation. In females the absence of the fifth cusp in mandibular first molars was related to small canine width and to a late cessation of skeletal growth.
Fluoride Acquisition in Vitro by Etched Enamel from Acidulated Phosphate-Fluoride Preparations
Authors: Mellberg Iames R. , Loertscher Kenneth L.
Published: November 2010

Fluoride uptake by acid-etched human enamel from acidulated phosphate-fluoride solutions was determined and compared with previous findings with sound enamel. Etched enamel acquired about five times more fluoride than sound enamel. The relative efficacy of different fluoride solutions was not always the same with etched and sound enamel.
Comparison of Rheological Properties of Four Dental Restorative Materials
Authors: Torgalkar Anil M.
Published: November 2010

Rheological properties of aged specimens of four restorative materials were investigated at 37 C by a nondestructive test method using an acoustic spectrometer. An amalgam was found to have the highest Young's modulus and lowest dynamic viscosity. A Poisson's ratio of about 0.2 was obtained for all of the dental restoratives.
Role of Attrition and Occlusal Contact in the Physiology of the Rat Incisor: VII. Formation of Impeded and Unimpeded Incisors in Magnesium-Deficient Rats
Authors: Weinreb M.M. , Kusner W. , Michaeli Y.
Published: November 2010

Odontogenesis in the basal end of the rat incisor depends to a considerable degree on the amount of occlusal pressure that is present and the amount of eruption that results. When occlusal pressure is removed and a certain amount of eruption takes place, dental tissues will form in the normal pattern, even under conditions of severe nutritional or hormonal deficiencies.
Action of Fluoride on Salivary Lysozyme
Authors: Mechin J.C. , Toury CH
Published: November 2010

Lysozyme activity was inhibited by increasing the ionic concentration beyond isotonicity, irrespective of the type of ion present. No specific inhibitory effect of fluoride ions on lysozyme activity was demonstrated.
Effect of Undernutrition During the Perinatal Period on Caries Development in the Rat: II. Caries Susceptibility in Underfed Rats Supplemented with Protein or Caloric Additions During the Suckling Period
Authors: Menaker Lewis , Navia Juan M.
Published: November 2010

The specific role of protein deficiency in altering dental caries incidence in rat pups was investigated. A 10% protein supplement given to undernourished rats during development allowed them to overcome weight deficiencies and reversed dental caries to the low incidence found in well-nourished control rats. Caries in undernourished rats supplemented with an isocaloric, proteinfree solution, was as high as that of undernourished rats intubated with distilled water.
Ultrastructure of Human Enamel Specimens Prepared by Ion Micromilling
Authors: Hamilton W.J. , Judd G. , Ansell G.S.
Published: November 2010

Ion-thinning techniques for the preparation of transmission electron microscope samples of mature enamel were used to examine ultrastructural details that included crystallite size and orientation in relation to the enamel rod geometry. The three-quarter arcade of the sheath is visible as the perimeter of the keyhole. Diffraction studies indicate a preferred orientation in the c axis of the crystallites in the head and tail of the keyhole and in other directions in the head region.
Elasticity of Elastometer Impression Materials : II. Permanent Deformation
Authors: Kaloyannides Thanos M.
Published: November 2010

The permanent deformation of all elastomer impression materials currently in use in Greece was studied. Measurements were made at ten minutes and 24 and 48 hours after mixing the materials. Silicone and polyether materials showed much less permanent deformation than the mercaptan materials in the measurement ten minutes after mixing.
An Experimental Radiopaque Composite Material
Authors: Barton J.A. , Burns C.L. , Chandler H.H. , Bowen R.L.
Published: November 2010

Numerous physical properties of a new reinforced resin were found to be similar to those obtained with earlier composite material formulations.
Oxytalan Fiber System of Molars in the Mouse Mandible
Authors: Sims Milton R.
Published: November 2010

The periodontal ligament of molars in mice includes an oxytalan fiber system that extends uninterruptedly from the first to the third molar. These fibers are not anchored in bone but they coordinate the movement of the tooth to the periodontal vasculature. The hypothesis is proposed that oxytalan fibers may be part of a mechanism that regulates vascular flow.
Movements of the Jaw After Unexpected Contact with a Hard Object
Authors: Gibbs Charles H. , Suit Stanley R.
Published: November 2010

Responses to sudden contact of the teeth with a hard object hidden in soft food were investigated in seven individuals. The result recorded was unexpected stoppage of jaw movement, rather than a jaw opening reflex commonly thought to occur.
Wear of Fluorapatite Single Crystals : V. Influence of Environment on Frictional Behavior and Surface Failure
Authors: Powers J.M. , Ludema K.C. , Craig R.G.
Published: November 2010

The influence of environment on the frictional behavior and surface failure of fluorapatite single crystals was evaluated for sliding in air, water, and dimethylformamide. The coefficient of friction was independent of environment. The ductile-to-brittle transition, however, occurred at a lower load in water than in air.
Wear of Fluorapatite Single Crystals : VI. Influence of Multiple-Pass Sliding on Surface Failure
Authors: Powers J.M. , Ludema K.C. , Craig R.G.
Published: November 2010

The influence of multiple-pass sliding on the surface failure of fluorapatite single crystals was evaluated. The surface and subsurface damage on the basal plane of fluorapatite was accelerative, rather than additive. Damage was more severe for sliding in opposite directions than for two traversals in the same direction.
Lipid and Calculus Matrix Calcification In Vitro
Authors: Ennever J. , Vogel J.J. , Benson L.A.
Published: November 2010

Lipid is necessary for calcification of a calculus matrix. Matrix was prepared by decalcification of dental calculus. The matrix calcified when it was exposed to a metastable calcium phosphate solution. After extraction with chloroform-methanol, the matrix lost the capacity to calcify. The lipid extract was calcifiable.
Comparison of the Effects of Parasympathetic Denervation and Administration of Testosterone Propionate on Submaxillary Glands of Male Mice
Authors: Houssay A.B. , De Harfin J.F. , Peronace A.A.V.
Published: November 2010

Histometric studies were done of the submaxillary glands of male mice. Parasympathetic denervation induced atrophy of the acini and slight atrophy of the tubules. Castration induced atrophy of the tubules and the administration of testosterone Propionate produced hypertrophy of the tubules, but the acini were not altered.
Genetic and Epidemiologic Studies of Oral Characteristics in Hawaii's Schoolchildren: Dietary Patterns and Caries Prevalence
Authors: Hankin Jean H. , Chung Chin S. , Kau Manuel C.W.
Published: November 2010

The relationship between the frequency of eating various foods and caries was studied in 910 eighth grade students of different races in Hawaii. There was a significant positive association between the frequency of candy and gum intake and DMF teeth. Racial differences still persisted after accounting for the dietary variation.
Mechanism for the Retardation of the Acid Dissolution Rate of Hydroxyapatite by Strontium
Authors: Dedhiya Mahendra G. , Young Fudah , Higuchi William I.
Published: November 2010

Dissolution rates and apparent solubilities for synthetic hydroxyapatite in acetate buffers containing phosphate and strontium ions in the range of 10-3 to 10-2 M were determined under various pH and buffer conditions. Critical examination of the role of strontium with a physical model suggests that a calcium-strontium apatite surface complex may govern the driving force of the dissolution reaction.
Effect of Occlusal Trauma on Interstitial Pressure in the Periodontal Ligament
Authors: Palcanis Kent G.
Published: November 2010

Tissue fluid pressure in the periodontal ligament was measured in dog canine teeth placed in traumatic occlusion for 48 hours. The pressure in experimental teeth was 19 mm Hg, which is significantly higher than the 10 mm Hg recorded for contralateral control teeth.
Eruption of Permanent Teeth in Mongoloid Children and Their Sibs
Authors: Orner Gerald
Published: November 2010

Eruption constants for the permanent dentition were determined in 212 mongoloid children and 124 of their unaffected sibs. Eruption of the permanent teeth in sibs was like that of other normal children. Mongoloid children resembled their sibs in general characteristics of tooth eruption, but showed a consistent tendency toward later mean ages of eruption for each tooth type.
Analyses of Components of Periodontal Disease
Authors: Glass Robert L. , Loftus Edward R. , Kapur Krishan K. , Alman John E.
Published: November 2010

Six variables associated with periodontal disease were evaluated in 635 men. Correlations between individual variables were low to moderate.' Highest correlations were observed between bone loss and tooth mobility. Principal component analysis of the intercorrelation matrix, followed by Varimax rotation of the factor matrix, demonstrated two distinct factors, periodontitis and gingivitis.
Linear Growth Study of the Pharyngeal Cavity
Authors: Castelli Walter A. , Ramirez Perla C. , Nasjleti Carlos E.
Published: November 2010

A cephalometric study was made to determine average linear dimensions and growth differentials of the pharyngeal cavity in boys and girls 6 to 15 years of age. The length of the cavity and its nasal openings had a faster rate of growth in boys than in girls, especially during puberty. Oral opening and laryngeal inlet did not vary between sexes.
A Study of the Dental Student-Patient Relationship
Authors: Weinstein Philip , Smith Timothy A. , Bartlett Richard C.
Published: November 2010

We attempted to establish standard patient measures by which to evaluate patients' reactions to dental care and to relate them to charasteristics and attitudes of dental students. Three sets of analyses were reported: relationships of student attitudes, personalities, and grades; relationships of patients' dissatisfaction, anxieties, and discontinuation of treatment; and relationshps between dental student measures and patient measures.
Enzyme-Histochemical Determination of Human Bone Growth Activity in Postmortem Material
Authors: Kjær Inger , Prydsoe Uwe
Published: November 2010

Autopsy material from calvarian bones and sutures of two children, was used to determine growth activity by measuring enzyme alkaline Phosphatase activity. In the extremely active periosteum of the 2-day-old boy, differences in growth activity could be demonstrated by reduction of the temperature of the incubation medium from room temperature to 4 C.
Automated Diagnosis of Craniofacial Pain
Authors: Leonard Michael S. , Roberts Stephen D. , Fast Thomas B , Mahan Parker E.
Published: November 2010

One of the techniques of automated diagnostic classification, pattern recognition, was applied to the problem of classifying patients with craniofacial pain. Dental data relevant to the classification process and the automated classifier are presented. Classifier training and accuracy of the automated process are discussed.
Electron Microscopic Study of the Effect of Water Jet Lavage Devices on Dental Plaque
Authors: Brady John M. , Gray Walter A. , Bhaskar Surindar N.
Published: November 2010

The maxillary posterior teeth of nine rhesus monkeys were treated with a pulsating water lavage instrument at 70 psi (high setting). Electron microscopic studies of pre- and post-lavage plaque samples showed that water jet devices as used in this experiment either removed the plaque completely or caused irreversible damage to the microbial forms in the plaque matrix.
Assessment of Sutural and Cranial Growth in Young Guinea Pig Skulls: A Quantitative Tetracycline Labeling Study
Authors: Malloy Randolph B.
Published: November 2010

Photographs of labeled bone regions measured planimetrically showed statistically significant differences in the values for bone formation in sutural and nonsutural sections, in different regions, and in different age and sex groups.
Effect of Soft Tissues on Radiographic Measurements of the Head
Authors: Boersma H.
Published: November 2010

Measurements on standardized lateral radiographs of monkey heads and subsequently of the dried skulls did not show statistically significant differences. The error of the method in the heads was on the average six times greater for the linear dimensions and four times greater for the angular dimensions than those in the skulls.
Temporary Suppression of Streptococcus mutans in Humans through Topical Application of Vancomycin
Authors: De Paola Paul F. , Jordan Harold V. , Berg Joel
Published: November 2010

Vancomycin, an antibiotic with desirable properties for oral usage, was applied in a 15% gel formulation to the teeth of children, and as a 1% paste to the teeth of young adults. Temporary suppression was observed in the presence of Streptococcus mutans, an organism which has been implicated in human dental caries.
Intermaxillary Relationships During Deglutition
Authors: Lard W.R.E.
Published: November 2010

Investigations were performed to assess the degree of tooth contact during deglutition. Graphic recordings of vertical jaw movement during deglutition were obtained from partially edentulous patients by means of an intraoral transmitting system. The incidence and position of tooth contact and its relationship to prosthodontics was studied.
Pulp Reaction to a Polycarboxylate Cement in Monkeys
Authors: El-Kafrawy A.H. , Dickey D.M. , Mitchell D.F. , Phillips R.W.
Published: November 2010

Pulp response to a polycarboxylate cement was evaluated microscopically in 48 teeth with intact dentin floors, and in 55 teeth with exposed pulps. The innocuous effect of polycarboxylate cements on the pulp was substantiated, although its use for pulp capping is not recommended.
Tensile Bond Strength Between Fissure Sealants and Enamel
Authors: Williams B.F. , Von Fraunhofer J.A. , Winter G.B.
Published: November 2010

Acrylic buttons were attached to tooth enamel by in situ curing of three types of polymeric fissure sealants, a dental cement, and a glass ionomer cement and then were immersed in water. The polymeric materials exhibited the greatest bond strengths to enamel, but in two instances the bond strength decreased with time although the cements showed increased strength. One polymeric material exhibited an unchanged bond strength.
Effects of Ready-to-Eat Breakfast Cereals on Dental Caries Experience in Adolescent Children: A Three-Year Study
Authors: Rowe Nathaniel H. , Anderson Ray H. , Wanninger Lester A.
Published: November 2010

The 375 adolescent public school children who participated in a permissive three-year breakfast consumption study showed no differences in dental caries experience whether they ate ready-to-eat breakfast cereals or other dietary regimens.
Local Clearance of 131I-4-Iodoantipyrine in Oral Mucosa and Subcutaneous Tissue of Cats
Authors: Gangarosa Louis P.
Published: November 2010

131I-4-iodoantipyrine clearances from injection sites in oral submucosa were at least twice as rapid as clearances in subcutaneous tissue in cats. There was a positive correlation between the rapidity of clearances in the two tissues. Epinephrine, a vasoconstrictor, depressed clearances in both tissues, whereas papaverine, a vasodilator, increased clearances.
Variations in the Crystalline Components of Human Dental Calculus: I. Crystallographic and Spectroscopic Methods of Analysis
Authors: Zapanta Le Geros Racquel
Published: November 2010

The diffractometric method has more advantages than the camera technique for X-ray diffraction analysis of the crystalline components of human dental calculus. With the use of this crystallographic method and infrared absorption techniques, it was found that the magnesium content of human dental calculus is the result of partial substitution of magnesium for calcium in whitlockite, and that the carbonate content is the result of substitution in apatite.
Fluoride Secretion in Rat Bile
Authors: Parkins F.M. , Greenlimb P.E.
Published: November 2010

The rate of bile secretion in fasted male rats and corresponding bile and plasma fluoride concentrations were studied to determine if significant quantities of fluoride are secreted into the small intestine from the bile duct during fluoride absorption. The osmolalities and fluoride levels were similar to those of plasma ; this suggests that the rat biliary system does not concentrate fluoride.
A New Dental Superalloy System: V. Embrittling Phase Transformations
Authors: Mohammed Hamdi , Asgar Kamal
Published: November 2010

The σ phase is rich in Ta. When the Ta concentration is less than 14%, σ does not interfere with the slip mechanism; when the Ta concentration is more than 15%, σ interferes with the slip mechanism. The coherent α-Co 3Ta phase forms at Ta concentrations of less than 15%, whereas incoherent γ-Co 2Ta forms only at higher Ta concentrations. The interface between σ and the matrix is an important factor in the failure mechanism.
Comparable Bactericidal Activity of two Chemosterilizers
Authors: Hill W.J. , Malveaux F.J. , Whitehurst V.E.
Published: November 2010

Bactericidal activity of a phenolic and a quaternary ammonium compound was assessed in the presence and absence of protein when certain bacteria were adsorbed to porous and nonporous surfaces. Organisms were more resistant when adsorbed to porous surfaces. Protein contributed to increased survival of bacteria only when adsorbed to porous surfaces.
Improved Method of Neutron Activation Analysis for Microleakage Studies
Authors: Meyer J.M. , Dennison J.B. , Craig R.G.
Published: November 2010

Improvements in the neutron activation technique for studying microleakage were achieved by selecting more suitable tracers and by using a more accurate method for evaluation of the activation data. Dysprosium was the most suitable tracer; it provided the least variation in the results and allowed the fastest activation and counting procedure.
Effects of Proteolytic Enzymes on Posteruptive Maturation, Remineralization, and the Caries-Preventive Effects of Fluoride in Rats
Authors: Briner W.W. , Henderson C.C. , Widder J.S.
Published: November 2010

The object of these studies was to determine the effect of topically applied bacterial proteases on posteruptive maturation of rat molars, on remineralization of incipient lesions in rats, and on the caries-preventive effect of fluoride in rats as evidenced by changes in hypomineralized areas in molars. Our findings showed that the topically applied proteases had no effect on the foregoing phenomena.
Comparison of Oral Health in Four Canadian Indian Communities
Authors: Myers Gordon S. , Lee Melvin
Published: November 2010

Dental caries and periodontal disease experience varied considerably among four populations of Indian communities although environmental conditions seemed similar.
Penetration of Commercial and Dental Waxes
Authors: Powers J.M. , Craig R.G.
Published: November 2010

Penetration of commercial and dental waxes was studied. Measurements indicated that resistance of paraffin and dental inlay waxes to penetration was closely related to the temperature at which solid-solid transformations occurred. Annealed waxes were more resistant to penetration than unannealed waxes.
Controlled Test of the Analgesic and Relaxant Properties of Nitrous Oxide
Authors: Devine Vernon , Adelson Richard , Goldstein Joel , Valins Stuart , Davison Gerald C.
Published: November 2010

The pain-reducing and calming properties of nitrous oxide mixed with oxygen were evaluated with the use of placebo and standard control groups. Subjects under nitrous oxide had higher pain thresholds and a higher tolerance for shock than placebo and control subjects. They also reported themselves as more relaxed than did placebo and control subjects.
Histological Study of the Periapical Tissues of Incompletely Formed Pulpless Teeth Filled with Zinc Preparations and with Magnesium Hydroxide
Authors: Rowe A.H.R. , Binnie W.H.
Published: November 2010

The effect of various zinc preparations and magnesium hydroxide on the apical tissues of incompletely formed premolars in dogs was studied histologically. Favorable results were obtained in 13 of 19 instances where zinc oxide and eugenol were used. Zinc oxide with water or zinc sulfate solution and magnesium hydroxide with water produced unsatisfactory results.
Studies on Oral Lichen Planus : I. Serum Immunoglobulins and Complement
Authors: Griffith M. , Kaufman H.S. , Silverman S.
Published: November 2010

In this preliminary study we explored the possibility of an immunologic component in oral lichen planus by assessment of serum immunoglobulins and complement levels, by skin tests for cellular immunity, and by fluorescent antibody techniques to detect immunoglobulins in the lesions. Although certain abnormalities were noted, none was consistent or of significant magnitude to clarify the cause of this disease.
Effect of Fluoride on Extracellular Polysaccharide Production by Streptococcus mutans
Authors: Bowen W.H. , Hewitt Merilyn J.
Published: November 2010

Fluoride at a concentration of 70 ppm in a dialyzed medium influenced the growth of cariogenic streptococci and also extracellular polysaccharide production. In four of five strains tested higher yields of microorganisms were obtained from the medium without added fluoride. Fluoride also affected the composition of the polysaccharide produced. The ratio of fructose to glucose usually was substantially higher in the fluoride group than in the control groups.
Electromyographic Analysis of the Circumoral Muscles of Facial Expression
Authors: Lehr Robert P. , Blanton Patricia L. , Biggs Norman L. , Sewell David A.
Published: November 2010

Electromyography of the circumoral muscles was undertaken with the use of fine-wire electrodes that were inserted into of hair follicles of ten patients with full dentitions and normal occlusion. The inferior circumoral muscles, which initiated many oral activities, had a higher degree of activity than did the superior circumoral muscles. Tonic discharge during mandibular rest was infrequent.
Transverse Strength of Aluminous and Feldspathic Porcelain
Authors: Sherrill C.A. , O'Brien W.J.
Published: November 2010

The transverse strength of aluminous porcelain was compared with that of feldspathic porcelain and the effect of surface roughness and environmental moisture on these strengths was determined. Aluminous porcelain was superior to feldspathic porcelain in transverse strength and the transverse strength of both types of porcelain was affected adversely by environmental moisture.
Elastase Production by Oral Staphylococci
Authors: Murphy Richard A.
Published: November 2010

Cultures of staphylococci isolated from the mouth and nose were assayed for their ability to degrade various proteins including elastin. Almost two thirds of the oral cultures and over a half of the nasal cultures produced elastase. Results indicated this to be an extracellular, constitutive enzyme. A role for oral staphylococci in periodontal disease is postulated.
Frequency of Cleft Uvula and Submucous Cleft Palate in Patients with Down's Syndrome
Authors: Schendel S.A. , Gorlin R.J.
Published: November 2010

Of 389 patients with Down's syndrome, 18 exhibited bifid uvula (4.63%) and 3 exhibited submucous cleft palate (0.77%). The hypothesis that cleft uvula and submucous cleft palate are micromanifestations of the more severe isolated cleft palate seems to be correct.
Organic Polymeric Polyphosphonates as Potential Preventive Agents of Dental Caries : In Vitro Experiments
Authors: Anbar M. , St. John G.A. , Scott A.C.
Published: November 2010

Organic polymeric polyphosphonates adsorb on enamel surfaces in the form of a monolayer and inhibit calcium and fluoride ion transport but not that of phosphate ions. The polymers investigated include phosphonated polyethylene, polyvinylphosphonate, and polyvinylbenzylphosphonate. The adsorption of proteins on enamel, as exemplified by human serum albumin, is diminished and the adsorbed protein is more readily desorbed from surfaces with polymeric polyphosphonates. These jendings may offer an explanation for the anticariogenic effect of polymeric polyphosphonates.
Effects of Age and Years of Exposure on the Economic Benefits of Fluoridation
Authors: Doherty Neville , Powell Elbert
Published: November 2010

The study shows how econometric techniques can be applied in analyzing the benefits of preventive dental care. The relationship between age and children's dental costs before and after fluoridation is analyzed. Results show that while costs increase with age, their level and rate of increase are lower after fluoridation.
Composition Stability of Gold Base Dental Alloys for Different Melting Techniques
Authors: Tuccillo Joseph J. , Lichtenberger H. , Nielsen John P.
Published: November 2010

The current precious metal dental alloys are apt to contain base metal additions that tend to "fire refine" out of the alloy. In the set of representative alloys examined, the copper and silver contents remained relatively stable. Iron oxidized out severely using torch or induction melting; it oxidized out mildly using resistance furnace melting. New metal additions to the charge can offset the base metal losses.
Dynamics of Dental Occlusion in Baboons
Authors: Zanowiak Paul P.
Published: November 2010

An investigation of the dynamics of dental occlusion in baboons showed mandibular movement to be rotary and cyclic and to include lateral motion. The path of motion was related directly to the dental articulation, and it was not restricted by the overlapping canines, indicating a major premise of the cuspid-rise theory is invalid.
Growth of the Palate and Maxillary Dental Arch
Authors: Cleall John F.
Published: November 2010

A histological study of rats using bone markers revealed sites and directions of growth of the maxillas.
Effects of a Simulated Skylab Mission on the Oral Health of Astronauts
Authors: Brown Lee R. , Wheatcroft Merrill G. , Frome William J. , Rider Linda J.
Published: November 2010

Laboratory and clinical findings related to the oral tissues of three astronauts during a 56-day simulated Skylab mission are described. Changes in the oral counts of specific microorganisms were observed concurrently with alterations in saliva flow rates and levels of secretory IgA and salivary lysozyme.
Determination of Strontium in Ground and Whole Teeth by X-ray Emission Spectrography
Authors: Kubota J. , Lazar V.A. , Losee F.L. , Curzon M.E.J.
Published: November 2010

Concentrations of strontium in samples of human enamel were determined by X-ray emission spectrography and compared with analyses of the same samples by atomic absorption. The spectrographic method is a rapid, nondestructive means to determine relative concentrations of strontium in tooth tissue samples.
Letters to the Editor
Authors: Kamen Alec
Published: November 2010

The Journal devotes this section to comment by readers on topics of current interest to dental research. The editor reserves the right to edit all communications to fit available space and requires that all letters be signed. Printed communications do not necessarily reflect the opinion or official policy of the Association. Your participation in this section is invited.
Glass Ceramics as Composite Fillers
Authors: Müller G.
Published: November 2010

Glass ceramics are known that are transparent and colorless and have very low thermal expansions. Experiments are described to modify such glass ceramics by introduction of oxides of high atomic weight. Glass ceramics containing relatively large amounts of La 2O3 are promising as X-ray opaque filler materials with nearly zero thermal expansion.
Hyponatremia and Hypernatremia Effects on Salivary Glands of the Rat
Authors: Esposito E.J. , Beasley Joe D.
Published: November 2010

A sodium chloride-deficient diet and a control diet were supplemented with different amounts of sodium chloride and fed to rats. The effects of these treatments over different experimental periods were observed on salivary glandular tissue by gross and histological methods. Weight, reversible and irreversible histologic changes, and sialolithiasis are reported.
Further Studies of the Cariostatic Properties of Tin (II) and Oat Hulls in the Rat
Authors: Stookey George K. , McDonald James L.
Published: November 2010

Two experimental dental caries studies were conducted in rats to investigate further the cariostatic activity of oat hulls and tin (II). The findings confirm the cariostatic activity of oat hulls regardless of the nutritional content of the diet, indicate that tin (II) may exert cariostatic activity depending on the concentration and nutritional content of the diet, and that the two agents are partially additive at tin (II) concentrations of 15 and 75 ppm but are not synergistic.
Interdental Thickness Discrimination by Normal Subjects
Authors: Williams William N. , Lapointe Leonard L. , Thornby John I.
Published: November 2010

Twenty-four adults made judgments of relative thickness of Plexiglas wedges placed inter dentally. Obtained difference limen values were consistently lower than those previously reported. Degree of mouth opening had no significant effect on performance. These data contribute to our understanding of sensory-perceptual factors in the regulation of chewing and speech.
Reactions in Glass Ionomer Cements: II. An Infrared Spectroscopic Study
Authors: Crisp Stephen , Pringuer Martin A. , Wardleworth Dion , Wilson Alan D.
Published: November 2010

The transmission and attentuated total reflectance spectra of a dental cement formed from an aluminosilicate glass and aqueous polyacrylic acid (ASPA) are reported. Interpretation of spectra show that a siliceous hydrogel is formed together with the polyacrylate salts of calcium and aluminum. In the fully hardened cement a minor proportion of -COOH remains unconverted to — COO- groups for steric reasons.
Reactions in Glass Ionomer Cements: III. The Precipitation Reaction
Authors: Crisp Stephen , Wilson Alan D.
Published: November 2010

Water-soluble ions in dental cements of different ages were studied. The cement is formed by the reaction between aqueous polyacrylic acid and an aluminosilicate glass. Electrical conductance measurements were made on cements up to three months after formation. Calcium polyacrylate is formed before aluminum polyacrylate. Calcium ions are fully combined within three hours, whereas aluminum ions continue to react for at least 48 hours.
Circadian Mitotic Rhythms in the Cervical Tissues of the Rat Maxillary Incisor
Authors: Kiely Michael L. , Wilde J.L.
Published: November 2010

A pronounced 24-hour fluctuation occurs in the mitotically active tissues of the rat maxillary incisor. High and low periods of activity were seen during the daytime as well as at night. A consistent increase in the number of mitotic figures occurred approximately four hours subsequent to a change in the light-dark regimen.
Five-Year Changes in the Edentulous Mandible as Determined on Oblique Cephalometric Radiographs
Authors: Winter Chester M. , Woelfel Julian B. , Igarashi Takayoshi
Published: November 2010

Oblique cephalometric radiographs were used to study mandibular resorption and denture settling on 45 patients wearing complete dentures; patients had either anatomic, nonanatomic, or semianatomic posterior teeth. The anatomic occlusal group had significantly less resorption and somewhat less denture movement from rest position to centric occlusion during five to seven years.
Dentinoenamel Junction Area of a Resorbing Permanent Incisor Studied by Means of Scanning Electron Microscopy
Authors: Sela J. , Sela M. , Lustmann J. , Ulmansky M.
Published: November 2010

The surfaces of enamel and dentin that had become separated from each other presumably in the region of the dentinoenamel junction were examined. The enamel surface at the junction was scalloped; the scallops were made of enamel rods. The dentinal surface showed a mirror image picture, tubular in nature. Both surfaces were granulated, which may indicate that apatite crystals from the two tissues intermingle there.
Electron Microscopic Study of the Cytotoxicity of Cadmium and Mercury In Vitro
Authors: Kawahara H. , Takashima Y. , Nakamura M. , Yamagami A.
Published: November 2010

The cells treated with cadmium chloride showed severe changes: ribosomes disappeared, mitochondria showed various degrees of destruction, and the endoplasmic reticulum had a swollen and beadlike appearance. In cells treated with mercuric chloride, ribosomes increased in their density and rosette-like polysomes were predominantly observed. The effects of these two metallic ions were discussed.
Effect of Temperature and Humidity on the Adhesive Strength of Orthodontic Direct Bonding Materials
Authors: Khowassah M.A. , Bishara S.E. , Francis T.C. , Henderson W.
Published: November 2010

The effects of temperature and humidity on the adhesive strength of two direct bonding orthodontic materials were investigated. Tensile testing showed that the adhesive bond was much stronger than the polycarbonate brackets. There is a significant increase in tensile and shearlike strength after 15-, 22-, and 30-day incubation at 37 C and 100% humidity, as compared with initial strength (after 30 minutes) at room temperature.
Hypodontia: A Polygenic Trait-A Family Study among Israeli Jews
Authors: Chosack Aubrey , Eidelman Eliecer , Cohen Tirza
Published: November 2010

A high prevalence of hypodontia was detected among 820 first degree relatives of 305 probands and there was an increased risk if a second family member was affected. Hypodontia is a common trait in the population, and a deviation from normal sex ratio was observed in those affected. These results suggest a polygenic mode of inheritance.
Elasticity of Impression Materials: IV. Permanent Deformation as a Function of Time
Authors: Kaloyannides Thanos M. , Christidou L.
Published: November 2010

The permanent deformation-time relationship under constant load, of 15 elastomer impression materials were studied. All materials showed a greater permanent deformation under constant load than with tensile load, except the polyether material. Silicone and polyether materials exhibited perceptibly less permanent deformation than mercaptan materials ten minutes after mixing.
Assessment of Microleakage Using a Conductimetric Technique
Authors: Jacobsen P.H. , Von Fraunhofer J.A.
Published: November 2010

A new method enables the dimensional changes of a range of anterior restorative materials to be demonstrated in an artificial cavity. The cavity wall-restoration interspace was incorporated into an electrochemical cell and the changes in the current passing through this cell reflected changes in the dimensions of the interspace.
Extractions in the Presence of Acute Infections
Authors: Martis C.S. , Karakasis D.T.
Published: November 2010

Of 1,376 extractions performed in the presence of acute infection, 327 were performed in the presence of a coexisting fascial space abscess. No serious complications were observed. It seems that the relation of dental operations to the intracranial infections has been overestimated. The extraction of teeth in cases of acute suppurative infection treats the primary dentoalveolar infection and prevents the development of fascial space abscesses.
Formation of CaHPO4 · 2H2O in Tooth Enamel as an Intermediate Product in Topical Fluoride Treatments
Authors: Chow Laurence C. , Brown Walter E.
Published: November 2010

Significant amounts of CaHPO4 · 2H2O (DCPD) were deposited in tooth enamel by pretreatment with a solution saturated with respect to DCPD. When these enamel samples were treated with a given fluoride solution, the fluoride uptake increased with increasing amounts of DCPD produced by the pretreatment. The interactions between enamel and acidic solutions to yield DCPD can be understood as dissolution-precipitation reactions and analyzed through the use of solubility phase diagrams.
Potential Applications of Certain Nickel-Titanium (Nitinol) Alloys
Authors: Civjan Simon , Huget Eugene F. , DeSimon Laszlo B.
Published: November 2010

The mechanical behavior ("shape memory") associated with martensitic solid-state transformation in nearly equiatomic Ni-Ti alloy (55-Nitinol) has been studied. Potential dental and medical applications for 55-Nitinol (~55% Ni, 1.5% Co, balance Ti, by weight) and for 60-Nitinol (~60% Ni, by weight) have been suggested.
In Vivo Tetracycline Labeling of Experimentally Induced Reparative Dentin in Human Teeth
Authors: Tagger M. , Perlmutter S. , Galon H. , Helft M.
Published: November 2010

Tetracycline hydrochloride was administered to label reparative dentin in teeth indicated for extraction. Deep cavities or pulp capping performed on the teeth one to four months before extraction served as a stimulus for new dentin formation. Examination of undemineralized sections under ultraviolet light revealed fluorescent bands in the reparative dentin of most teeth. The technique can be safely used in studies of the effects of clinical procedures on the dentin and pulp of human teeth.
Mixtures of Elastomer Impression Materials: II. Measurement of Young's Modulus of Elasticity and Permanent Deformation
Authors: Kaloyannides Thanos M. , Kapari Danae J.
Published: November 2010

An experiment was carried out to determine the Young's modulus of elasticity and the permanent deformation of 16 mixtures of elastomer impression materials. The permanent deformation was measured in tension and compression of the samples and the results were compared.
Autotransplants and Allotransplants of Teeth in the Subcutaneous Tissue of Rabbits : A Histological Study
Authors: Birman Esther G. , Soares de Araujo Ney
Published: November 2010

Autotransplants and allotransplants of rabbit teeth were performed heterotopically into the subcutaneous tissue and were studied morphologically and histochemically. The results suggest that the periodontal ligament plays a major role in the success of tooth transplantation.
Peripheral Blood Toxicity of Topical 5-Fluorouracil on the Syrian Hamster Cheek Pouch
Authors: Cherrick Henry M. , McKelvy Bruce D.
Published: November 2010

Toxicological studies on the peripheral blood after topical application of 5-fluorouracil to the buccal pouch of the Syrian hamster showed that a daily application of 10 μl (0.5 mg) was the maximum ideal dose for this animal. This dose did not depress to a significant degree the white blood cell count, red blood cell count, hemoglobin level, hematocrit value, or the peripheral differential blood counts after 14 daily applications. Doses of increased concentration either daily or periodically were less effective and toxic.
Labeling Index and Cell Density of Aging Rat Oral Tissues
Authors: Toto Patrick D. , Rubinstein Alicia S. , Gargiulo Anthony W.
Published: November 2010

Age changes were detected in oral epithelium, dental pulp, and periodontal ligament in the Simonsen rat.
Effect of Infusing Selected Chemical Compounds on Dentinal Fluid Movement in the Rat
Authors: Steinman Ralph R. , Leonora John
Published: November 2010

Intra-arterial infusion of carbamyl phosphate or of carbamyl-DL-aspartic acid into rats on a cariogenic diet greatly stimulated the movement of fluid through the odontoblastic processes. The infusion of sodium cyanate also stimulated fluid movement. Guanidine HCl and L-asparagine were active at higher concentrations. Purifying the urea on a mixed-bed ion exchange resin virtually removed its stimulatory effect on dentinal fluid movement. The action of urea is apparently attributable to contamination with sodium cyanate.
Effect of Selected Dietary Additives on the Incidence of Dental Caries in the Rat
Authors: Steinman Ralph R. , Leonora John
Published: November 2010

Weanling rats fed a cariogenic diet supplemented with carbamyl phosphate, in combination with egg shell meal and trace elements, showed a striking reduction in the incidence of caries. The cariostatic efficacy of carbamyl phosphate is significant because it stimulates fluid movement within odontoblasts via the hypothalamic-parotid gland endocrine axis.
Antibodies in the Saliva and Serum of Rats Sensitized by Intraductal Instillation of Antigen into the Parotid Gland
Authors: Boss J.H. , Rosenmann E. , Sela J. , Ulmansky M. , Dishon T.
Published: November 2010

Instillations of bovine serum albumin into the parotid gland of rats elicit a local and systemic immune response, the former being the more pronounced response. With increasing number of intraductal instillations of antigen, the titers of antibodies in the saliva and serum rise progressively.
An Epidemiologic Study of Deciduous Molar Relations in Preschool Children
Authors: Infante Peter F.
Published: November 2010

This study indicated that distoclusion decreased significantly with age and was more prevalent in siblings of children with Class II molar relation as compared with the prevalence for the total population. Children of middle socioeconomic status (SES) and girls with Class I molar relation had prevalences of posterior crossbite significantly greater than lower SES children and boys, respectively. Finger habits were highly associated with posterior crossbite (P < 0.001)
Residual Fluoride Concentrations and Scanning Electron Microscopic Examination of Root Surfaces of Human Teeth After Topical Application of Fluoride In Vivo
Authors: Ehrligh J. , Hochman N. , Gedalia I. , Tal M.
Published: November 2010

Fluoride concentrations in root surfaces of human teeth after a single topical application with a 2% acidulated sodium fluoride solution in vivo were investigated. Increased residual fluaride concentrations in the root surfaces and precipitations on the peritubular dentin, as revealed by SEM micrographs, may be factors in reducing hypersensitivity.
Polyurethane Elastomer As a Possible Resilient Material for Denture Protheses: A Microbiological Evaluation
Authors: Tang Robert Y.W. , Gonzalez Juan B. , Roberts Glenn D.
Published: November 2010

A polyurethane elastomer was microbiologically evaluated in vitro for its potential use in resilient denture liners. Specimens were immersed in suspensions of ten selected oral microorganisms; this was followed by viable cell counts at intervals during a 16-week period. Results indicated that the polyurethane neither supported the growth of the organisms nor was it degraded.
Truncated Poisson Distribution with Optimization Techniques in the Epidemiology of Caries
Authors: Singh Chanchal , Snyder C. William
Published: November 2010

A truncated Poisson distribution provides a closer fit to observed caries in a sample of 10-to 11-year-old children than a previously reported chain binomial distribution. Operations research techniques are used in estimating a parameter.