bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Science
Authors: Blaschke Donald D. , Blaschke Thomas J.
Published: November 2010

In a preliminary investigation, condyle-temporal bone spatial relationships were determined quantitatively in 50 asymptomatic TMJs (25 subjects) by making area measurements of the posterior and anterior portions of the joint spaces. For both right and left sides, the numerical expression of the joint relationship indicated that the condyle is normally centered in the joint to a very high degree. Standard deviations around the mean joint relationship values were large, however, which suggests that the posteroanterior variation of condyle positions in asymptomatic TMJs is greater than commonly thought. In addition, there was only mild correlation between individual joint relationships on right and left sides.
Clinical Science
Authors: Elattar Tawfik M.A. , Lin Hsien S.
Published: November 2010

The levels of cAMP were measured by means of radioimmunoassay in 20 gingival samples free from inflammatory cells and 43 samples with moderately dense and dense aggregations of inflammatory cells. The average values were found to be 340 ± 44 and 552 ± 59 pmol/gm wet tissue, respectively. The increase in cAMP levels in inflammation is suggested to be modulated by an increase in endogenous prostaglandin synthesis and could be one of the natural mechanisms by which the host protects itself from dangerous consequences of unregulated immune response.
Traumatized Anterior Teeth in Iraqi and Sudanese Children-A Comparative Study
Authors: Baghdady Virgin S. , Ghose Leonora J. , Enke Helmut
Published: November 2010

This epidemiological study describes the prevalence of trauma to the anterior teeth of 6090 Iraqi and 3507 Sudanese primary school children. 7.7% of Iraqi and 5.1% of Sudanese presented incisal trauma. The male to female ratio was 1.3:1 in Iraqis and 2.6 :1 in Sudanese.

The frequency of trauma to Iraqi females below age nine yr was higher than the males, but the condition was reversed with age. In Sudanese children the frequency was higher in males in all age groups.

In general, males suffered a higher rate of trauma in both countries, but the Iraqi children had a significantly higher rate of trauma than the Sudanese in both sexes.
Failure at the Margin of Amalgams as Affected by Cavity Width, Tooth Position, and Alloy Selection
Authors: Osborne J.W. , Gale E.N.
Published: November 2010

The effects of alloy, cavity width, and tooth position on failure rate at the margins of 429 two-year-old Class II amalgams were analyzed. Interpretation of the results from a factorial design indicated that: (1) There were significant differences among alloys; (2) conservative preparations exhibit less breakdown than wider preparations; and (3) there was less failure in lower premolars than in other posterior teeth.
Masticatory Muscle Silent Periods in Patients with MPD Syndrome Before and After Treatment
Authors: Skiba Thomas J. , Laskin Daniel M.
Published: November 2010

Masticatory muscle silent periods were compared in normal subjects and in patients with MPD syndrome before and after a variety of psychological, physiological, and pharmacological forms of therapy. All patients initially showed prolonged silent periods in one or more of the muscles. There was a direct relationship between prolongation and severity of symptoms. The temporalis (90.9%) and masseter (54.5%) were most frequently involved. In almost all instances the silent periods returned to the normal range following treatment.
In vitro Corrosion and Tarnish Analysis of the Ag-Pd Binary System
Authors: Vaidyanathan T.K. , Prasad A.
Published: November 2010

Binary compositions over the entire range of compositions of the Ag-Pd system are characterized by anodic polarization in Ringer's solution and alternate immersion in 0.5% Na 2S solution. The results show that a wide range of protection and passivation tendencies are introduced with Pd alloying of Ag.
The Laser-Raman Spectroscopic Studies on Human Enamel and Precipitated Carbonate-containing Apatites
Authors: Nishino Mizuho , Yamashita Shinsuke , Aoba Takaaki , Okazaki Masayuki , Moriwaki Yutaka
Published: November 2010

Laser-Raman spectra of synthetic apatites containing from zero to 12.4 wt% carbonate ions and enamel apatite are reported. Special attention is paid to the correlation between the intensities of the carbonate, phosphate, and hydroxyl modes and the carbonate content in the apatites. The data presented here indicate that most of the CO2-3 in corporated in the apatite lattice substitutes for PO3-4 and suggest that a small amount of CO 2-3 might be located in the OH- position.
Peroxidase Antimicrobial System of Human Saliva: Requirements for Accumulation of Hypothiocyanite
Authors: Thomas E.L. , Bates K.P. , Jefferson M.M.
Published: November 2010

Human saliva was fractionated to determine the components required for production and accumulation of the antimicrobial oxidizing agent, hypothiocyanite ion (OSCN-). The required components were: 1) peroxidase activity and thiocyanate ion (SCN -), 2) the saliva sediment, which produced hydrogen peroxide (H 2O2) in the presence of oxygen and a divalent cation, and 3) heatstable factors of the saliva supernatant. The supernatant factors were separated into high- and low-mol wt fractions. The high-mol wt fraction contained both peptide and carbohydrate, and its activity was partially inhibited by proteolytic treatment. The low-mol wt fraction contained carbohydrate and could be replaced by a number of mono- and di-saccharides. Glucosamine and N- acetyl glucosamine were the most effective, whereas neutral sugars such as sucrose were less effective. Sucrose competed with glucosamine, so that lower levels of OSCN- were obtained with increasing amounts of sucrose. The sugars stimulated production of H202 by the saliva sediment. Production of H202 was greater in the presence of glucosamine than of neutral sugars. Also, the ratio of OSCN- accumulation to H202 production was greater in the presence of glucosamine. The results suggest that peroxidase-mediated antimicrobial activity is modulated by the carbohydrate composition of whole saliva and by certain protein and glycoprotein components.
Fracturing Molars with Axial Forces
Authors: Re Gerald J. , Norling Barry K.
Published: November 2010

Extracted human molars were prepared with different sized occlusal cavities and restored with a high-copper amalgam. Loads were applied along the long axis of the teeth, and forces required to fracture the teeth were recorded. More force was required to break samples with the larger restorations than was required to break samples with the smaller restorations.
Mode of Occurrence of Brushite and Whitlockite in a Sialolith
Authors: Sakae Toshiro , Yamamoto Hirotsugu , Hirai Goro
Published: November 2010

A micro-focus X-ray diffractometer was applied to a ground section of sialolith, and localization of brushite and whitlockite was found. The sialolith was composed of a central core of organic material and a layered cortex of mineral components. The major component of the mineral cortex is apatite. Brushite and whitlockite locate independently at the surface layer of the cortex.
Identification of Hyaluronidase Activity in Rabbit Dental Pulp
Authors: Sakamoto N. , Nakajima T. , Ikunaga K. , Shidahara H. , Okamoto H. , Okuda K.
Published: November 2010

A hyaluronidase activity was demonstrated in rabbit dental pulp. The optimum pH of the enzyme was 3.8. The enzyme activity was enhanced by protamine and poly-L-lysine and was inhibited by iodoacetamide, ferric ion, and ferrous ion in decreasing order. The product of the enzyme reaction was identified as tetrasaccharide. From these results it was concluded that the enzyme exists in pulp tissue and is functioning for degradation of proteoglycans in situ.
Estimation of Physiologic Stresses with a Natural Tooth Considering Fibrous PDL Structure
Authors: Atmaram Gobind H. , Mohammed Hamdi
Published: November 2010

Finite element analysis is used to determine the physiological stress values in the natural tooth and the underlying bone. In addition to modeling the periodontal ligament (PDL) as a continuous structure as considered in previous studies, the PDL is modeled more accurately in a novel fashion as a fibrous structure. The results indicate that the type of PDL modeling has a significant effect on the nature and magnitude of alveolar stresses, and that the fibrous PDL modeling shows higher and more widely distributed lateral tensile stresses in the alveolar bone than those resulting from the continuous PDL modeling.
Effect of Topically-applied Solutions of Iodine, Sodium Fluoride, or Chlorhexidine on Oral Bacteria and Caries in Rats
Authors: Caufield Page W. , Navia Juan M. , Rogers Angela M. , Alvarez Celestino
Published: November 2010

Antibacterial levels of iodine, chlorhexidine, or sodium fluoride were topically applied to the molar teeth of rats. The effect of these agents on buccal and sulcal caries, as well as on certain oral bacterial populations was assayed. All three agents exerted a significant cariostatic effect which was site specific. Buccal caries incidence and reductions appeared correlated to S. mutans counts, while sulcal caries was better correlated to total cultivable counts. These studies suggested that the simultaneous application of iodine and NaF might exert an additive cariostatic effect.
Characteristics of Submandibular Glands from Young and Aged Rats
Authors: Kuyatt Brian L. , Baum Bruce J.
Published: November 2010

Submandibular glands from young adult and aged male and female rats have been examined and various descriptive parameters obtained. Several sex differences were observed with tissue from young and old animals. Sex differences were found in the gland contents of DNA, protein, and sialic acid and in some protein components resolved by gel electrophoresis. Significant age-related decreases in the gland contents of protein, sialic acid, and neutral sugar, but not DNA, were found with male rats. In female rats these values were constant across the animal's adult lifespan.
High-voltage Electron Microscopy of Radiation Damages in Octacalcium Phosphate
Authors: Aoba Takaaki , Takahashi Junzo , Yagi Toshio , Doi Yutaka , Okazaki Masayuki , Moriwaki Yutaka
Published: November 2010

The present high-voltage electron microscopic study showed two types of radiation damages in OCP. The first type commenced with the formation of voids, which later grew and coalesced along the c-axis. The second type was characterized by the appearance of paired and concentric strain fields and the subsequent formation of dislocations. The origin of the strain fields is attributed tentatively to a precipitation of a second phase in the crystal.
Basic Biological Sciences
Authors: Turner J.W. , Jordan H.V.
Published: November 2010

Actinomyces strains were tested for evidence of bacteriocin-like antagonism. Prevalence of inter-strain antagonism was low, and, when present, zones of inhibition were generally small and poorly defined. Strains of A. viscosus were very susceptible to bacteriocin-like inhibition by S. mutans. Prevalence of inhibition was high, and zones of inhibition tended to be large and well defined. Inhibitors produced by S. mutans were generally heat stable, nondialyzable, and sensitive to proteolytic enzymes. Individual strains of A. viscosus could be differentiated on the basis of sensitivity patterns to a battery of S. mutans strains.
The Relation of Keratinization to Bacterial Colonization on the Baboon Tongue as Demonstrated by Scanning Electron Microscopy
Authors: Aufdemorte T.B. , Cameron I. L.
Published: November 2010

Scanning electron microscopic observations of the baboon tongue demonstrating specificity of microbial distribution as related to epithelial keratinization are presented. The number of bacteria inhabiting a surface was related to the degree of keratinization. Orthokeratotic dorsal tongue surfaces were most heavily colonized by bacteria. The parakeratotic and non-keratinized surfaces were less heavily populated, with non-keratinized areas showing the fewest numbers of bacteria.
Inhibitory Effects of Inhaled Methyl Methacrylate Vapor on Amphibian Skeletal Muscle
Authors: Martin J.S. , Digioia W.J. , Werley M.S. , Tansy M.F.
Published: November 2010

The effect of inhaled vapors of methyl methacrylate (MMA) at a 2000 ppm concentration was studied on electrically stimulated in situ amphibian skeletal muscle preparations. Upon exposure to the vapor for 30 min, there was a significant fall in maximal twitch tension, a depression in elicited responses to a train of tetanizing stimuli and an upward and rightward shift in the strength-duration curve. Responses during a 30-minute post-exposure recovery period seldom reached sham control values.
Clinical and Laboratory Evaluation of Some Othodontic Direct Bonding Systems
Authors: Beech D.R. , Jalaly T.
Published: November 2010

Shear and tensile bond strengths of five representative types of acid etch direct bonding adhesives have been compared with their clinical performance using both metal and plastic brackets. Taking the various clinical factors into account, the material with the lowest bond strength- ordinary self-curing acrylic with 20-50% phosphoric acid etchant - was considered to be the best system.
Determination of Stress Patterns in Root-filled Teeth Incorporating Various Dowel Designs
Authors: Davy D.T. , Dilley G.L. , Krejci R.F.
Published: November 2010

A theoretical investigation has utilized the finite element technique to analyze mechanical stress patterns in a reconstructed maxillary central incisor. A series of designs for endodontic dowel posts incorporated into the prostheses has been comparatively evaluated. For the load condition considered, the results show that minor changes in the stress patterns are produced by the post diameter, length, and taper variations considered.
The Accelerative and Adhesive Bonding Capabilities of Surface-active Accelerators
Authors: Antonucci J.M. , Misra D.N. , Peckoo R.J.
Published: November 2010

PolySAM-1, a multifunctional surface-active amine polymerization accelerator, and several simpler surface-active amine promoters were evaluated for their accelerative and adhesion-promoting potentials. Diametral tensile strength measurements, performed on composites prepared from a bis-GMA resin formulation with tribasic calcium phosphate as the filler, were used to assess the adhesive bonding capabilities of these amines.
4-N,N-Dialkylaminophenethanols,-Alkanoic Acids and Esters: New Accelerators for Dental Composites
Authors: Brauer G.M. , Stansbury J.W. , Antonucci J.M.
Published: November 2010

The newly synthesized 4-N,N-dialkylaminophenethanol, 4-N,N-dialkylaminophenalkanoic acid and ester are highly reactive accelerators for the polymerization of composites. With low amine concentration, nearly colorless restorations having good color stability are obtained.
The Adherence to Bone by Cytoplasmic Elements of Osteoclasts
Authors: Ryder M.I. , Jenkins S.D. , Horton J.E.
Published: November 2010

The intimate association observed between osteoclasts and bone has suggested that these cells may be adherent to the bony surface. We investigated this cell-surface relationship in parathyroid hormone-stimulated bone explants following applications of biophysically-induced cell detachment forces. Bone surfaces adjacent to disrupted osteoclasts were examined with transmission electron microscopy for the presence of residual cell membrane elements. Results of this study provide evidence for the adherence of osteoclasts to bony surfaces and implicate elements of both clear zone and ruffled border as cell-membrane bonded sites.
Effect of K2SO4 and CaSO4 Dihydrate Solutions on Crystallization and Strength of Gypsum
Authors: Shen C. , Mohammed H. , Kamar A.
Published: November 2010

Crystal formations obtained from evaporating clear filtrates of dental stone mixed with various solutions were examined with an optical and scanning electron microscope. It was found that when K2SO4 was present in any concentration, a spherulitic structure dissimilar to that of CaSO4 2H2O and K2SO4 was dominant. It is concluded that syngenite (a complex compound of CaS04 and K2SO4) forms at the center of the nuclei of crystallization and is responsible for spherulitic formation. The use of K2SO4 solution and saturated CaSO 4 solution was also found to improve the strength both at one and 24 h.
Decomposition of Gypsum Bonded Investments
Authors: Matsuya S. , Yamane M.
Published: November 2010

Decomposition of gypsum bonded investments was investigated by means of TG-DTA and X-ray diffraction. The decomposition began at about 900°C and led to the formation of CaSi03 as a major product and Ca2SiO4 as a minor one. CaO was not formed during the decomposition of any of the investments. The decomposition process followed Jander's equation, [1-(1-α)1/3]2 = kt, and the Ca2+ ion diffusion in CaSi03 was concluded to be a rate-detennining step.
Evaluation of an Oligomer or an Oligomer Plus Cetyl Pyridinium Chloride Against Plaque, Stain, Calculus, and Gingivitis
Authors: Gaffar A. , Niles H.P. , Davis C.B.
Published: November 2010

A low molecular weight oligomer of sulfoacrylic acid (ND-2) was effective in inhibiting hydroxyapatite formation in vitro at 33 ppm from a saturated solution of calcium and phosphate. The oligomer did not damage or etch human dental enamel in vitro at pH 5.0 and 7.5. It significantly reduced calculus formation when applied topically in beagles at a concentration of 1% in a rinse. In a second study using 30 beagle dogs, the rinses containing 0.1% CPC and 0.1% CPC + 2% ND-2 significantly reduced (a < 0.05) plaque and gingivitis for 12 wk when compared to a placebo rinse, One-tenth percent CPC rinse induced more discoloration of teeth than the placebo, while the rinse containing 0.1% CPC + 2% ND-2 had significantly less discoloration than CPC rinse or the placebo rinse in beagles. Thus the oligomer was effective in reducing CPC-induced discoloration in beagles.
Current Concepts of the Mechanism of Action of Local Anesthetics
Authors: Strichartz Gary R.
Published: November 2010

Recent experiments are reviewed to present a current view of the mechanisms of conduction block by local anesthetics. Local anesthetics block the sodium channels whose opening causes the rising phase of the action potential. Both charged and neutral forms of local anesthetics are able to block channels. Charged anesthetics interfere with a "gating" mechanism after gaining access to a "receptor" site in the aqueous pore of the channel from the axoplasmic surface of the membrane. This site is only available to charged compounds when the gate of the channel is open. In contrast, uncharged compounds (including the free base form of local anesthetics) appear to reach the site through the membrane's lipid interior, bypassing the channel "gates. " Anesthetics blocking the gate of the channel can either enhance or inhibit the normal inactivation mechanism of the sodium channel, depending on the particular anesthetic.
Effect of Stannous Fluoride Treatments on the Progression of Initial Lesions in Approximal Surfaces of Permanent Posterior Teeth
Authors: Powell K.R. , Barnard P.D. , Craig G.G.
Published: November 2010

Home use of a SnF2 dentifrice in combination with the professional application of a 10% SnF2 solution markedly retarded the growth of initial lesions over a four-year period. Overall, the SnF2 dentifrice alone showed inhibitory properties, whereas the SnF2 solution alone had no discernible effect on lesion development.
Variables Discriminating Individuals who Seek Orthodontic Treatment
Authors: Albino J.E. , Cunat J.J. , Fox R.N. , Lewis E.A. , Slakter M.J. , Tedesco L.A.
Published: November 2010

Characteristics differentiating two groups of adolescents were identified: those planning orthodontic treatment and a comparison group not planning treatment. Two separate analyses, for psychosocial and dental-related variables, were completed. Additional analyses were applied using salient variables for each group. Eighty-two percent of the subjects were correctly categorized using the resulting discriminant function.
In vitro Accelerated Aging of Composites and a Sealant
Authors: Powers J.M. , Fan P.L. , Marcotte M.
Published: November 2010

The in vitro accelerated aging of conventional and microfilled composite restorative materials and a sealant was studied. Volume loss/surface area ranged from 2.0 to 7.3 x 10-3 mm3/mm2 after 900 h of aging. Surface morphology changed more dramatically for the conventional composites than for the other materials. Changes in surface chemistry as measured by FTIR-ATR were observed.
Color Stability and Aging of Plastic Veneering Materials
Authors: Powers J.M. , Fan P.L.
Published: November 2010

The color stability and aging characteristics of commercial plastic veneering materials were studied in vitro by an accelerated aging method. The veneering materials were similar in color to, but more opaque than, composite restorative materials. Changes in color during aging were minimal. Weight loss occurred during aging.
Tongue Brushing, Dentifrice, and Age Effects on Taste and Smell
Authors: Hyde R.J. , Feller R.P. , Sharon I.M.
Published: November 2010

Tongue brushing with and without dentifrice in young adult and old subjects affected taste detection thresholds, but not taste intensity scaling, for sucrose, NaCl, citric acid, and caffeine. Citric acid (sour) and caffeine (bitter) tasted significantly less intense in the older subjects. Olfactory detection thresholds for pyridine improved slightly after tongue brushing in the older subjects.
Sexual Dimorphism in the Development, Emergence, and Agenesis of the Mandibular Third Molar
Authors: Levesque G.-Y. , Demirjian A. , Tanguay R.
Published: November 2010

The development, alveolar emergence, and agenesis of the mandibular third molars, in a homogeneous group of French-Canadian children and young adults ranging in age from seven to 25 yr, were evaluated from 4640 panoramic radiographs using the method of Demirjian et al. 8 Clinical emergence was recorded from dental casts of children between 15 and 19 yr. The occurrence of bilateral agenesis was about 9%, without significant sexual difference. The left and right third molars had the same pattern of crown and root development and emergence. Girls were ahead of boys up to the second half of crown formation, but this sexual difference disappeared at the first stage of root formation. The root development course was faster in males than in females. At the apex closure, the sexual difference was much more marked for retarded cases (about 2.7 yr) than for median (1.5 yr) or advanced cases (0.4 yr). For alveolar and clinical emergence, males were about six mo ahead of females at the median level.
Pressures Created by Dental Injections
Authors: Pashley E.L. , Nelson R. , Pashley D.H.
Published: November 2010

In routine dental practice, anesthetic solutions are injected into tissue sites of widely different distensibilities, under a variety of pressures. The purpose of the present study, during simulated dental practice, was to determine the maximum injection pressures obtained by clinicians during injections in dogs. Regular aspirating dental syringes were used together with dental anesthetic cartridges filled with isotonic saline. Maximum operator injection pressures ranged from 330 to 660 psi (17,061-34,122 mmHg). Those injection sites that were least distensible gave the highest maximum injection pressures: interosseous (21,559 mmHg); incisive papilla (18,224 mmHg); periodontal (17,630 mmHg); hard palate (11,322 mmHg); and intrapulpal (8918 mmHg). More distensible tissue sites gave much lower pressures. The data indicate that dental injection pressures vary widely from several hundred mmHg to several hundred psi, depending on the clinician's physical effort and the distensibility of the tissue.
Calcifiability Comparison Among Selected Microorganisms
Authors: Ennever J. , Streckfuss J.L. , Goldschmidt M.C.
Published: November 2010

Seven reference-strain bacteria were examined for apatitic calcifiability in a chemically-defined medium and in a metastable calcium phosphate solution. The results support the belief that calcification is limited to certain microorganisms. Additionally, the findings emphasize that determining microbiologic calcifiability only in a calcification-supporting medium is too restrictive.
Dentin Hydraulic Conductance: Changes Produced by Red Blood Cells
Authors: Pashley D.H. , Nelson R. , Williams E.C.
Published: November 2010

Red blood cells were forced into dentinal tubules in vitro under known hydrostatic pressures. This resulted in a 1 7-fold fall in the hydraulic conductance of dentin. The histologic appearance of red blood cells forced into dentin in vitro was very similar to that found in dog pulps following full crown preparations without adequate cooling in vivo.
Identification of Phospholipids and Neutral Lipids in Human Gingival Fluid
Authors: Pellat B.P. , Kohaut J.C.
Published: November 2010

Gingival fluid was collected from children with a gingival index score of 2. Lipids were extracted, purified, and separated by thin-layer nanochromatography and identified. Lysophosphatidylcholines, sphingomyelins, phosphatidyl-cholines-ethanolamines-serines-inositols, polyglycerophosphatides, diphosphatidylglycerols, non-esterified fatty acids, mono- and di-glycerides, and cholesterols were observed. Serum origin of these lipids was possible, but enrichment by salivary bacterial or tissue lipids cannot be eliminated.
Comparison Among a Dip-slide Test (Dentocult®), Plate Count, and Snyder Test for Estimating Number of Lactobacilli in Human Saliva
Authors: Birkhed D. , Edwardsson S. , Andersson H.
Published: November 2010

Saliva samples from 120 individuals were cultured by three methods: (a) Dentocult, incubated four d at 37°C or six d at room temperature, (b) SL agar technique, and (c) Snyder test. In a supplementary study with 77 subjects, and comparing only the two former methods, the incubation time with Dentocult at room temperature was prolonged to nine d. The authors also studied whether the number of lactobacilli was influenced by storage time, transport medium, and sampling time of day.
Materials Science
Authors: Morrison J.T. , Duncanson M.G. , Shillingburg H.T.
Published: November 2010

Wax pattern surface treatments were compared to determine their effectiveness in reducing contact angles incident at wax pattern-investment interfaces.. Gypsum-bonded and phosphate-bonded investments were examined. A coordinate system was used to obtain a polynomial expression from which the contact angles could be determined.
The Effects of Cavity Smear Layer Removal on Experimental Marginal Leakage around Amalgam Restorations
Authors: Jodaikin A. , Austin J.C.
Published: November 2010

Unvarnished freshly-packed dental amalgam restorations leak initially. However, with time, a marginal seal is usually effected. It is not known whether the smear layer which forms during cavity preparation is associated with this leakage pattern. This study was undertaken to evaluate experimental marginal leakage around amalgam restorations (left in situ for one and 12 wk) which had been placed in cavities prepared with and without removal of the smear layer in vital and devitalized teeth. The cavities were obturated with two types of dental amalgams, a conventional and a dispersed-phase amalgam. The excised teeth restorations were subjected to a fluorescent dye marginal leakage experiment. All of the short-term specimens leaked severely, but some of the long-term specimens displayed significant sealing properties. No significant differences were found between the two types of amalgams. However, the non-vital tooth specimens and cavities without smear layers displayed significantly improved sealing properties.
The in vivo Effects of an Antiseptic Mouthwash on Odor-producing Microorganisms
Authors: Pitts G. , Pianotti R. , Feary T.W. , McGuiness J. , Masurat T.
Published: November 2010

Oral odorigens were quantitated by specific, functional assays; oral malodor was simultaneously measured organoleptically. An antiseptic mouthwash was found to depress malodor and populations of odorigenic bacteria for at least two h. These results support the hypothesis that the anti-odor properties of the product are related to its anti-microbial activity.
Contact Angle Measurements on Human Enamel — An in vitro Study of Influence of Pellicle and Storage Period
Authors: de Jong H.P. , van Pelt A.W.J. , Arends J.
Published: November 2010

In this study, contact angle (Θ) measurements on enamel from four patients were carried out in vitro. The experiments were done with and without the acquired pellicle. The results show that if ΘA, ΘB, and Θ C are the contact angles of enamel with pellicle, enamel 3-7 μm under the anatomical surface, and enamel 100-200 μm under the surface, then ΘA > ΘB > ΘC, respectively. The biological variation in one patient is comparable to the biological spreading among patients; the biological variations are several times greater than are the experimental errors. Storage experiments indicate that enamel surfaces change strongly after extraction if stored in water; main changes occur within one wk.
Clinical Science
Authors: Lupkiewicz S.M. , Gibbs C.H. , Mahan P.E. , Lundeen H.C. , Ariet M. , Sinkewiz S.L.
Published: November 2010

This study investigated irregularities in hinge movement in 113 subjects. These irregularities were analyzed by computer with an instantaneous three-dimensional "screw axis method. " The variation in hinge movement was measured by the dispersion of the hinge axis instant centers. Dispersion of instant centers was greater for muscle pain patients than for the normal, indicating that instant center data could make a contribution to diagnosis and treatment planning.
Metals in Solution in Mercury Expressed from Copper-rich Dental Amalgams
Authors: Paffenbarger G.C. , Rupp N.W. , Waterstrat R.M.
Published: November 2010

Metals dissolved in excess mercury expressed from copper-rich amalgams ranged from 0.06 to 0.63 wt %. Such small percentages are not likely to affect pertinent properties. The solubility data may assist in explaining the kinetics of hardening of amalgams.
Effects of Parasympathomimetic and Sympathomimetic Drugs on the Secretion and Composition of Rat Sublingual Saliva
Authors: Abe K. , Yokota Y. , Dawes C.
Published: November 2010

The sublingual glands of adult, male rats secreted considerable volumes of saliva in response to several cholinergic agonists, but very little in response to α-adrenergic stimuli and none in response to a β-adrenergic agonist. The types of proteins secreted were quite different from those in submandibular and parotid saliva or serum, and were largely independent of the nature of the stimulus. However, some differences in staining intensity of electrophoretic patterns occurred both between stimuli and with the same stimulus used on different rats.
A Comparative Study of Enzymes Involved in Glucose Phosphorylation in Oral Streptococci
Authors: Vadeboncoeur C. , Mayrand D. , Trahan L.
Published: November 2010

The properties of two enzymes involved in the phosphorylation of glucose were studied in three oral streptococci species. The glucokinase of Streptococcus mutans had a lower affinity for glucose and ATP than did those from S. salivarius and S. sanguis. The enzyme had an identical pH optimum (pH 8.0) in all three bacteria. However, the results from the phosphoenolpyruvate phosphotransferase system showed a different pattern when its activity was measured using 2-deoxyglucose with toluenized cells. Uptake studies of 2-deoxyglucose also revealed that the three microorganisms had different affinities for this compound. This glucose analogue strongly inhibited the acid production of S. salivarius, but did not affect the glycolysis of the other two bacteria.
Slots vs. Pins: A Comparison of Retention Under Simulated Chewing Stresses
Authors: Outhwaite W.C. , Twiggs S.W. , Fairhurst C.W. , King G.E.
Published: November 2010

Extracted human teeth have been used in an experiment comparing the fatigue life of amalgam and composite resin restorations using either threaded pins or an undercut slot for retention. The fatigue lives of restorations retained by either a slot or pins were comparable when amalgam was used. When composite resin was used, the slot-retained restorations had significantly longer lives.
Basic Biological Sciences
Authors: Uchtmann H. , Duschner H.
Published: November 2010

Electron spectroscopic depth profiles of the chemical composition of bovine incisors after fluoride treatment show that interactions are restricted principally to a hyperfine outermost layer of only 0.05 μm. In this zone, high fluoride concentrations of up to 20% are correlated with drastic surface enamel degradations. A mixed layer of calcium phosphates and calcium fluorides is formed.
Bacterial Invasion of Pulpal Dentin Wall in vitro
Authors: Akpata E.S. , Blechman H.
Published: November 2010

Instrumented root canals of extracted human teeth were inoculated with known pulpal bacterial isolates. The inoculated teeth were immersed in the appropriate culture media and incubated at 37° C for varying periods. Streptococci multiplied in the root canals and invaded the radicular dentinal tubules. The extent of bacterial invasion was time-dependent. This experimental model may be useful in investigating the effect of intra-canal medicaments on microorganisms lodged in the pulpal dentin wall.
Identification of PK 1 Bacteriophage DNA in Streptococcus mutans
Authors: Higuchi M. , Higuchi M. , Katayose A.
Published: November 2010

A lysogenic bacteriophage PK 1 and plasmid DNA's in Streptococcus mutans PK 1 have been characterized by electron microscopy. PK 1 phage DNA molecules were observed in both linear and circular forms, which gave the molecular weights of (28.9 ± 0.4) x 106 and (27.4 ± 0.2) x 106 daltons, respectively. Plasmid DNA has a molecular weight of 4.0 x 106 daltons. No difference of density in CsCl density gradient between linear and circular forms of phage DNA and plasmid DNA was observed.
Pharmacokinetics of Fluoride from APF Gel and Fluoride Tablets in Children
Authors: LeCompte E.J. , Whitford G.M.
Published: November 2010

During separate visits, four child volunteers received routine APF gel topical fluoride applications and ingested known amounts of fluoride (3.0 mg) in the form of tablets. Plasma and urine fluoride concentrations, as well as urine excretion rates, were measured before and for five h after these procedures. Significant increases in plasma and urinary fluoride concentrations were observed following both procedures.
Immunochemistry of Monkey Salivary Mucin
Authors: Hatton M.N. , Tabak L.A. , Levine M.J.
Published: November 2010

The immunochemistry of monkey salivary mucin was examined using a monospecific antiserum. Quantitative precipitation assays using various mucin derivatives indicated that the antiserum contained antibody populations with specificity toward carbohydrate moieties as well as toward non-glycosylated peptide regions. Using quantitative inhibition assays, the carbohydrate specificity was found to reside in a complex oligosaccharide containing fucose.
Mechanism of Epinephrine Enhancement of Lidocaine-induced Skeletal Muscle Necrosis
Authors: Yagiela J.A. , Benoit P.W. , Fort N.F.
Published: November 2010

Skeletal muscle damage produced in rats by 2% lidocaine in combination with agents that mimic or modify actions of epinephrine was assessed histologically. Only drugs producing vasoconstriction- epinephrine, phenylephrine, and felypressin — significantly augmented lidocaine myotoxicity. This potentiation was in direct relation to each drug's ability to retard absorption of the local anesthetic from its injection site.
Characterization of Cysteine-containing Phosphoproteins from Human Submandibular-Sublingual Saliva
Authors: Shomers J.P. , Tabak L.A. , Levine M.J. , Mandel I.D. , Ellison S.A.
Published: November 2010

Members of a family of acidic proteins taken from human submandibular-sublingual saliva were designated cysteine-containing phosphoproteins, since they could be distinguished from other salivary phosphoproteins by the presence of half-cystine. These molecules consisted of a single peptide chain of ~ 14,000 daltons. Their isoelectric points ranged from 4.3 to 5.9. Two groups (C2 and C3) were 0-phosphorylated. Their charge heterogeneity was apparently due to variations in content of phosphate and acidic and basic amino acids.
Unreacted Methacrylate Groups on the Surfaces of Composite Resins
Authors: Vankerckhoven H. , Lambrechts P. , Van Beylen M. , Davidson C.L. , Vanherle G.
Published: November 2010

The unreacted methacrylate groups on the surface of conventional composites and microfilled composites were studied by means of multiple internal reflection infrared spectroscopy. The influences of polymerization time, temperature, and the effect of polishing were studied. We also attempted to relate the results of some mechanical tests to the degree of chemical unsaturation measured in the different resins. All surface treatments and manipulative variables caused a decrease in double bond content and interfacial bond strength.
Properties of Ag-Cu-Pd Dispersed Phase Amalgams: Microstructures
Authors: Marshall G.W. , Marshall S.J. , Szurgot K. , Greener E.H.
Published: November 2010

A 62% Ag-28% Cu-10% Pd lathe-cut alloy was successfully blended with conventional lathe-cut and spherical amalgam alloy. The resulting alloy showed little γ2 after one wk at 37°C and a phase structure resembling commercial amalgam. In addition, the Cu 3Pd phase present in the dispersant appears to participate in the amalgam reaction and, as a result, Pd may be found in the reaction zone around the dispersants in γ1 and/or Cu6Sn5 phases.
Cemental Annulation as an Age Criterion in Forensic Dentistry
Authors: Stott G.G. , Sis R.F. , Levy B.M.
Published: November 2010

Intact teeth were obtained from three cadavers of known age 57, 67, and 76 years, respectively. Cross-sections 100-150 μm thick were taken from the roots using a diamond saw. Individual sections were stained, mounted on glass slides, and photographed on a light microscope. The usual number of years for the eruption of any particular tooth were added to the annulation count to determine the estimated age for that cadaver.
Confidence Intervals for Percentage Reduction in Caries Increments
Authors: Wallenstein S. , Fleiss J.L. , Chilton N.W.
Published: November 2010

Confidence intervals are presented for the percentage reduction in mean caries increments associated with a test treatment relative to the mean increment associated with control. Approaches based on both the analysis of variance and the analysis of covariance are compared with respect to ease of computation and to the length of the confidence interval.
The Effect of Supragingival Plaque Control on the Composition of the Subgingival Microbial Flora in Ligature-induced Periodontitis in the Monkey
Authors: Siegrist B. , Kornman K.S.
Published: November 2010

The influence of supragingival plaque control on the subgingival microflora and clinical parameters of ligature-induced periodontitis in the Cynomolgus monkey was investigated. No clinical changes were observed during the six-week experimental period. The total cultivable flora and the proportions of total black-pigmented Bacteroides (BPB) and asaccharolytic black-pigmented Bacteroides decreased significantly in the cleaned test sites as compared to those in the non-cleaned controls. The study suggests that six wk of supragingival plaque control in the presence of periodontal disease may alter the periodontitis-associated microflora in the monkey, but not sufficiently to alter clinical signs of disease in this time period.
The Effect of 5,5'-diphenylhydantoin on the Metabolism of 17β-estradiol by Rat Oral Mucosa
Authors: Vittek J. , Munnangi P.R. , Gordon G.G. , Rappaport S.C. , Southren A.L.
Published: November 2010

Systemic pretreatment of rats with 5,5'-diphenylhydantoin (DPH) or its addition into an in vitro assay increases microsomal hydroxylation of 17β-estradiol. This increase depends on the concentration of DPH in the microsomal cell compartment.
Evaluation of the Biologic Effects of Dental Materials Using a New Cell Culture Technique
Authors: Imai Y. , Watanabe A. , Chang P.-I. , Masuhara E.
Published: November 2010

The biological effects of seven dental cements — including zinc oxide-eugenol, EBA, silicate, zinc phosphate, silico-phosphate, polycarboxylate, and glass ionomer — and a composite resin were evaluated by a new cell culture technique. The agar overlay containing serum was proposed as a dentin model. The effects of thickness and serum concentration of the agar overlay on cell growth were studied and compared to in vivo findings. Some correlative phenomena between the cell culture results and in vivo data are presented.
The Isolation of a Family of Cysteine-containing Phosphoproteins from Human Submandibular-Sublingual Saliva
Authors: Shomers J.P. , Tabak L.A. , Levine M.J. , Mandel I.D. , Ellison S.A.
Published: November 2010

A family of acidic proteins has been isolated from human submandibular-sublingual saliva using Sephadex G-200 gel filtration, DE-52 cellulose chromatography, and immuno-affinity chromatography. These molecules were homogenous in size and by immunological criteria, but exhibited charge heterogeneity. The heterogeneity displayed was not due to gustatory stimulation or degradation during isolation procedures.
The Effects of Plasma and Salivary Constituents on Dentin Permeability
Authors: Pashley D.H. , Nelson R. , Kepler E.E.
Published: November 2010

The experiments described in this report were designed to determine the possible influence of plasma and salivary constituents on dentin permeability, in vitro. The results indicate that plasma, serum, and whole (mixed) saliva are all capable of causing immediate reductions in dentin permeability. Individual plasma protein fractions and several different types of bacteria were also effective in reducing the ease with which fluid can move across dentin. These observations may provide a mechanism for the "spontaneous" reductions in dentin sensitivity seen by clinicians following periodontal therapy.
Materials Science
Authors: Thompson L.R. , Miller E.G. , Bowles W.H.
Published: November 2010

The unpolymerized material extracted from cured orthodontic bonding resin was analyzed by UV spectrophotometry. Under certain conditions, substantial amounts of the material (approximately 14%) were leached from bracketed teeth. The possible carcinogenicity of these unpolymerized materials is discussed.
Clinical Science
Authors: Hoppenbrouwers P.M.M. , Borggreven J.M.P.M. , The G.S.T. , Maltha J.C.
Published: November 2010

Tritiated proline was administered to domestic cats during the development of their permanent dentition. The amount of residual radioactivity was determined autoradiographically at various times after cavity preparation in mature molars and premolars. Two wk after cavity preparation, the amount of radiolabel beneath the axial cavity wall decreased to about 50% of that present in corresponding contralateral cavity-free teeth. The observed decreases are ascribed to an enhancement of the protein metabolism in dentin. At 45 wk, 80-90% of the radiolabel has disappeared. This paper discusses the role of an eventual effect of microleakage on the latter results.
Development and Validation of a Measure of Attitudes Toward Malocclusion
Authors: Fox R.N. , Albino J.E. , Green L.J. , Farr S.D. , Tedesco L.A.
Published: November 2010

The Orthodontic Attitude Survey was designed to assess children's and their parents' attitudes toward malocclusion and orthodontic treatment. Five consistent clusters of attitudes had discriminant validity, and were significantly related to plans for orthodontic treatment and to objective and subjective indicators of the child's occlusal status and appearance.
Correlations Between Salivary Protease and Supragingival or Subgingival Calculus Index
Authors: Watanabe T. , Toda K. , Morishita M. , Iwamoto Y.
Published: November 2010

Significant positive correlations between protease activities in saliva and supragingival/subgingival calculus indices, periodontal pocket depth, or P-M-A index were confirmed. When the partial correlation was calculated, the subgingival calculus index correlated well with the sediment protease at pH 8.5, and the supragingival calculus index showed a significant correlation with the supernate protease at pH 4.5.
Fluoride Pharmacokinetics in the Domestic Pig
Authors: Richards A. , Fejerskov O. , Ekstrand J.
Published: November 2010

Plasma fluoride concentrations were studied in 11 pigs following single oral or intravenous doses of fluoride. The results showed a less-than-20% bioavailability of fluoride when administered with calcium-rich food. Pharmacokinetic analyses showed that the plasma half-life varied from 0.6 to 1.4 h, depending on diet and route of fluoride administration. These data are comparable to those reported for man, and thus illustrate the suitability of the pig for studies of effects of fluoride on hard tissues.
Influence of Aging on DNase Activity in Human Parotid Saliva
Authors: Yaegaki K. , Sakata T. , Ogura R. , Kameyama T. , Sujaku C.
Published: November 2010

The micro method of disc electrophoresis is introduced for determining DNase activity in human saliva. Acid DNase activity in an elderly age group was found to be low, compared with that in a young age group. However, electrophoretic properties of materials obtained from young and elderly age groups did not vary significantly.
Effect of Increasing Contact Time of Sucrose Solution or Powdered Sucrose on Plaque pH in vivo
Authors: Firestone A.R.
Published: November 2010

Interdental plaque pH, recorded in six volunteers during and after rinsing for one, two, four, eight, and two x four min with 15 ml of a 7.3 mM (0.25%) sucrose solution, declined continuously the longer the substrate was in contact with the plaque. The addition of a sticky, non-fermentable substrate to powdered sucrose significantly increased the acidogenic response of interdental plaque.
A Longitudinal Study of Caries Development in Initially Caries-free Naval Recruits
Authors: Walter R.G.
Published: November 2010

The purpose of this investigation was to determine the pattern of caries development in initially caries-free naval recruits during a four-year period. The results indicated that: (1) 37% of the individuals developed at least one carious lesion during the four-year study, (2) occlusal lesions occurred most frequently, (3) maxillary second molars were most frequently attacked, and (4) the development of caries mirrored the isolation frequency of Streptococcus mutans.
Dimensional Changes of Four Amalgams After Five Years of Storage in Air at 60, 37, and 23°C
Authors: Paffenbarger G.C. , Rupp N.W. , Coyne M.P.
Published: November 2010

Amalgam cylinders, 4 mm in diameter and 8 mm long, made from four alloys, expanded lengthwise from 204 to 220 at 60°C, 18 to 46 at 37°C, and 6 to 35 at 23°C, μm/cm, respectively, after storage in air at the indicated temperatures for five yr.
Behavior of Mast Cells in Periodontal Ligament Associated with Experimental Tooth Movement in Rats
Authors: Yamasaki K. , Shibasaki Y. , Fukuhara T.
Published: November 2010

Orthodontic mechanical stress reduced the frequency of the appearance of mast cells stainable with toluidine blue in the periodontal ligament on both the pressure and tension sides of rat molar teeth. This effect was seen immediately after insertion of elastic bands between the first and second molars, and the greatest reduction in the number of mast cells stainable with toluidine blue was observed 15 min after insertion.
Secretion of Protein by the Submandibular Glands of the Rat, Mouse, and Hamster in Response to Various Parasympatho- and Sympatho-mimetic Drugs
Authors: Abe K. , Dawes C.
Published: November 2010

The types of proteins secreted by the submandibular glands of rats in response to high doses of α-adrenergic agonists are electrophoretically different from those secreted in response to cholinergic and β-adrenergic agonists, but, in mice and hamsters, they appear to be independent of the nature of the stimulus.