bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of Sucralose on Bacterial Metabolism
Authors: Young D.A. , Bowen W.H. 
Published: November 2010

Sucralose (1',4',6' trideoxy-trichloro-galactosucrose) is a nontoxic, intensely sweet sucrose derivative that has been shown to be non-cariogenic in experimental animals. The purpose of this study was to determine whether certain oral bacteria could utilize sucralose. Sucralose, as a sole carbon source, was unable to support growth of ten strains of oral bacteria and dental plaque. When sucralose was incorporated into a liquid medium containing glucose or sucrose, all organisms tested displayed similar pH falls, compared with controls. The incorporation of 126 mmol/L sucralose into glucose agar medium caused total inhibition of growth of Streptococcus sobrinus 6715-17, Streptococcus sanguis 10904, Streptococcus sanguis Challis, Streptococcus salivarius, and Actinomyces viscosus WVU627. Sucralose had no effect on IPS production. Sucralose was not bound to, nor taken up by, cells. Sucralose inhibited the formation of glucan and fructan polymers in proportion to the sucralose-to-enzyme ratio, but independent of the sucrose concentration in the assay mixture. No radioactive polymer was formed from 14C-U-sucralose added to mixtures containing glucosyltransferase (GTF) or fructosyltransferase (FTF). Inhibition of GTF and FTF by sucralose was removed following dialysis of the enzyme/sucralose mixture. These results show that sucralose was not utilized by the oral bacteria tested and that the inhibitory effect of sucralose on GTF and FTF was non-competitive and reversible. The results further support the concept that sucralose is non-cariogenic.
Preliminary Surface Analysis of Etched, Bleached, and Normal Bovine Enamel
Authors: Ruse N.D. , Smith D.C. , Torneck C.D. , Titley K.C. 
Published: November 2010

X-ray photoelectron spectroscopic (XPS) and secondary ion-mass spectroscopic (SIMS) analyses were performed on unground un-pumiced, unground pumiced, and ground labial enamel surfaces of young bovine incisors exposed to four different treatments: (1) immersion in 35% H2O2 for 60 min; (2) immersion in 37% H 3PO4 for 60 s; (3) immersion in 35% H2O2 for 60 min, in distilled water for two min, and in 37% H3PO 4 for 60 s; (4) immersion in 37% H3PO4 for 60 s, in distilled water for two min, and in 35% H2O2 for 60 min. Untreated unground un-pumiced, unground pumiced, and ground enamel surfaces, as well as synthetic hydroxyapatite surfaces, served as controls for intra-tooth evaluations of the effects of different treatments. The analyses indicated that exposure to 35% H2O2 alone, besides increasing the nitrogen content, produced no other significant change in the elemental composition of any of the enamel surfaces investigated. Exposure to 37% H3PO4, however, produced a marked decrease in calcium (Ca) and phosphorus (P) concentrations and an increase in carbon (C) and nitrogen (N) concentrations in unground un-pumiced specimens only, and a decrease in C concentration in ground specimens. These results suggest that the reported decrease in the adhesive bond strength of resin to 35% H 2O2-treated enamel is not caused by a change in the elemental composition of treated enamel surfaces. They also suggest that an organic-rich layer, unaffected by acid-etching, may be present on the unground un-pumiced surface of young bovine incisors. This layer can be removed by thorough pumicing or by grinding. An awareness of its presence is important when young bovine teeth are used in a model system for evaluation of resin adhesiveness.
Gradual Increases in Marginal Leakage of Resin Composite Restorations with Thermal Stress
Authors: Momoi Y. , Iwase H. , Nakano Y. , Kohno A. , Asanuma A. , Yanagisawa K. 
Published: November 2010

The effects of thermal stress on the marginal leakage of resin composite restorations in bovine teeth were investigated by a method that preserved the specimens. The changes in marginal leakage of specimens with increasing numbers of thermal cycles were measured by an electrical conductivity method. Four brands of posterior resin composites were used to fill cylindrical cavities (2.0 mm in diameter and 1.5 mm in depth) on the labial surfaces of bovine incisors, according to the manufacturer's instructions. Thermal cycling stress was applied to the specimens for up to about seven weeks (9000 cycles). During this time, the electrical conductance between the pulp and a drop of physiological saline solution covering the resin restoration was measured periodically by application of an electrical potential (60 Hz, 10 Vp-p). Thermal stress increased the marginal leakage gradually, rather than step-wise. Even before application of any thermal stress, wide variations of marginal leakage were found among different specimens restored with the same brand of resin. Specimens with less initial leakage showed less increase in leakage, and vice versa, throughout the experimental period.
The Effect of Tin on the Corrosion Behavior of the Ag-Hg Phase of Dental Amalgam and Dissolution of Mercury
Authors: Marek M. 
Published: November 2010

The anodic polarization behavior of the Ag-Hg matrix phase of dental amalgam (γ1) and the rate of mercury dissolution were examined as a function of the tin content. The objectives were to determine the effect of tin on the electrochemical behavior and dissolution of mercury and to provide evidence on whether tin dissolves in the γ1 phase or precipitates as a tin-rich phase. Anodic polarization curves were recorded for specimens of the γ1 phase containing 0-1.5% Sn and for the γ2 phase and a γ2-containing dental amalgam, in synthetic saliva. Mercury dissolved in synthetic saliva in 24 h was determined for the γ1 phase containing 0-1.0% Sn, with cold-vapor Atomic Absorption Spectrophotometry used for mercury analysis. Tin induced passive behavior of the γ1 phase and suppressed mercury dissolution. The passive γ 1 phase did not exhibit a breakdown of passivity occurring at the γ 2 phase. The results were consistent with the tin presence in γ 1 in a solid solution, rather than in tin-rich precipitates, and indicated that at least 1.5% Sn can be dissolved in γ1 at 37°C.
Effects of Fluoride and Chlorhexidine on the Microflora of Dental Root Surfaces and Progression of Root-surface Caries
Authors: Schaeken M.J.M. , Keltjens H.M.A.M. , Van Der Hoeven J.S. 
Published: November 2010

The effects of fluoride and chlorhexidine varnishes on the microflora of dental root surfaces and on the progression of root-surface caries were studied. Forty-four patients, surgically treated for advanced periodontal disease, were distributed at random among three groups. All patients received a standardized preventive treatment. Furthermore, the dentition of the patients in the two experimental groups was treated, at three-month intervals, with chlorhexidine and fluoride varnish, respectively. Patients in the control group received no additional treatment. In the experimental groups, plaque samples were collected from selected sound and carious root surfaces at baseline and at three, six, and nine months after the onset of the study. The presence of root-surface caries was scored at baseline and after one year. In addition, the texture, depth, and color of the root-surface lesions were monitored. Mutans streptococci on root surfaces were suppressed significantly (p<0.05) during the whole experimental period in the chlorhexidine varnish group, but not in the fluoride varnish group. A non-significant increase in the number of Actinomyces viscosus/naeslundii was noted after treatment with chlorhexidine and fluoride varnish. The increase in the number of decayed and filled root surfaces after one year was significantly lower in the experimental groups than in the control group. After treatment with chlorhexidine varnish, significantly more initial root-surface lesions had hardened than in the other groups.
Single-dose Concentrations of Tinidazole in Gingival Crevicular Fluid, Serum, and Gingival Tissue in Adults with Periodontitis
Authors: Liew V. , Mack G. , Tseng P. , Cvejic M. , Hayden M. , Buchanan N. 
Published: November 2010

Previous studies have shown that metronidazole is effective in the treatment of subgingival microflora associated with destructive periodontitis. The aim of this study was to determine whether tinidazole, a close analogue of metronidazole, would reach sufficient concentrations in serum, gingival crevicular fluid, and gingival tissue, to inhibit putative periodontopathic bacteria. Ten adult patients with moderate to advanced periodontitis took a single 2-g dose of tinidazole orally. Samples were assayed by high-performance liquid chromatography. The concentrations of tinidazole in serum and GCF were in a similar range (3.2-46.5 μg/mL). Tinidazole was not detected in the GCF in three of the patients. The drug was found in gingival tissue obtained at two h (0.17 ± 0.14 μg/mg) and six h (0.15 ± 0.18 μg/mg) after oral administration. The mean concentration of tinidazole in serum at 24 h (13 ± 3.0 μg/mL) is greater than the minimum inhibitory concentration for anaerobic bacteria as reported by others. The present data suggest that a single 2-g oral dose of tinidazole may lead to the presence of potentially bactericidal levels of tinidazole for up to 24 h in the periodontal pockets of some patients with periodontitis.
Dentinal Fluid Movement Associated with Loading of Restorations
Authors: Hirata K. , Nakashima M. , Sekine I. , Mukouyama Y. , Kimura K. 
Published: November 2010

Post-operative biting sensitivity is a significant clinical problem after placement of posterior resin composites and may be due to dentinal fluid movement. The occlusal surfaces of extracted teeth were filled with amalgam (control) or various posterior resin composites, and the movement of the dentinal fluid induced by the loading of the restorations was studied. In addition, the firing of pulpal nerves induced by the loading of class 5 resin composite restorations in canine teeth of dogs was also investigated. When the entire cavity was etched with an acid gel and then filled with resin composite, dentinal fluid movement in response to loading was significantly (p<0.01) greater than in the amalgam-filled or unoperated controls. The dog canine tooth filled with resin composite showed firing of pulpal nerves when loaded. These results suggest that the movement of dentinal fluid induced by masticatory pressure on resin composite restorations may elicit biting sensitivity.
Evaluation of New Gingival Retraction Agents
Authors: Bowles W.H. , Tardy S.J. , Vahadi A. 
Published: November 2010

Current gingival retraction agents are not without undesirable side-effects; there appears to be no ideal gingival retraction agent. Several sympathomimetic amines, capable of producing local vasoconstriction with minimal systemic side-effects, are available as non-prescription nasal decongestants and eye washes. The purpose of this study was to evaluate the efficacy of three of these agents for gingival tissue displacement. Mongrel dogs were used as experimental subjects, in which pulse rate and blood pressure were monitored electronically. Visine® (tetrahydrozoline HCl, 0.05%), Afrin® (oxymetazoline, 0. 05%), and Neosynephrine®(phenylephrine HCl, 0.25%) were the commercial products studied as gingival retraction agents. Plain, untreated cord was used as a mechanical control, and as a vehicle for the three experimental agents. Commercially available cords impregnated with both racemic epinephrine (8%) and alum were also used as standard retraction agents with which the test solutions were compared. Visine and Afrin produced tissue displacement greater than that of any of the other agents; Neosynephrine, epinephrine, and alum were more effective than the untreated mechanical control. Cardiovascular changes included a slight increase in systolic pressure in the Neosynephrine group, and a slightly lower mean arterial pressure and pulse rate in all three experimental groups.
The Effect of Low-level Laser Treatment on Maxillary Arch Dimensions after Palatal Surgery on Beagle Dogs
Authors: De Braekt M.M.H. In , Van Alphen F.A.M. , Kuijpers-Jagtman A.M. , Maltha J.C. 
Published: November 2010

The effect of low-level laser treatment on maxillary arch dimensions after palatal surgery was investigated in Beagle dogs at an age of 12 weeks. A total of 30 dogs was used, and they were assigned to either a control group (Group C, n = 6) or one of two experimental groups (Group L, n = 12; and group LL, n = 12). After Von Langenbeck's palatal repair in the two experimental groups, denuded bony areas in the LL group were irradiated with a continuous Ga-As-Al laser beam (830 nm) and energy output set at 30 mW. A dosage of 1 J/cm2 wound surface area was used. Treatment was carried out three times a week, with a total of ten treatments. The animals of the L group served as non-treated control animals. Dental casts were made of all animals of all groups at regular intervals until they reached 25 weeks of age. Maxillary arch dimensions were studied. Dental arch dimensions in the deciduous dentition of both experimental groups were not disturbed by surgery, but after eruption of permanent teeth, mainly transvere maxillary arch dimensions in the premolar region increased less in both experimental groups than in the control group. It was concluded that low-level laser treatment under the conditions used in this study did not decrease the adverse iatrogenic effects of palatal surgery on maxillary arch dimensions.
Progression of Approximal Caries in Relation to Iatrogenic Preparation Damage
Authors: Qvist V. , Johannessen L. , Bruun M. 
Published: November 2010

The aim of the present study was to evaluate the effect of iatrogenic preparation damage on the need for operative caries treatment of approximal surfaces, adjacent to Class II amalgam restorations. The material was collected by 77 dentists from the Public Dental Child Health Service in Denmark. It consisted of die-stone models of 187 first-time Class II preparations, adjacent to 190 unfilled approximal surfaces of 58 primary and 132 permanent teeth. The cavity preparations were performed in children between 4 and 17 years of age. They were all filled with amalgam. Information about operative treatment and exfoliation or extraction of the preparation teeth and the adjacent teeth during the following seven years was obtained from the patients' records. sStereomicroscopic examination of the models revealed preparation damage on 64% of the unfilled approximal surfaces in primary teeth and on 69% of the corresponding test surfaces in permanent teeth. During the observation period, operative treatment was performed on 10% of the undamaged test surfaces in primary teeth and on 35% of the damaged ones (p < 0.05). The corresponding figures for test surfaces in permanent teeth were 6% and 15% (p < 0.05). It is concluded that iatrogenic preparation damage is a frequent side-effect of operative intervention with approximal caries lesions, and represents a dental health problem, since the damage increases caries progression and the perceived need for restorative therapy of the adjacent teeth.
Demand and Need for Treatment of Craniomandibular Dysfunction in the Dutch Adult Population
Authors: De Kanter R.J.A.M. , Kayser A.F. , Battistuzzi P.G.F.C.M. , Truin G.J. , Van't Hof M.A. 
Published: November 2010

A nationwide survey of oral conditions, treatment needs, and attitudes toward dental health care in Dutch adults was carried out in 1986. One of the aims of the study was to investigate the perceived need and demand for treatment of craniomandibular dysfunction (CMD). A sample of 6577 persons (15-74 yrs of age), stratified for gender, age, region, and socio-economic status, was contacted. Of this sample, 4496 persons participated in the behavioral part of the study, of which 3526 were examined clinically. The CMD-treatment demand was based on (1) CMD complaints in the past, (2) CMD complaints at present, and (3) an anticipated increase of the present complaints. CMD was both anamnestically and clinically assessed, independently by different examiners. A total of 21.5% of the Dutch adult population reported dysfunction, but 85% of these perceived no need for treatment. With most of the remaining 15% either seeking or intending to seek treatment (or having had it before), a figure of 3.1% can be used to summarize the actual level of treatment need for CMD in the Dutch adult population.
The Dependence of Shrinkage Stress Reduction on Porosity Concentration in Thin Resin Layers
Authors: Alster D. , Feilzer A.J. , De Gee A.J. , Moli A. , Davidson C.L. 
Published: November 2010

The development of polymerization contraction stress was determined as a function of the surface area of porosity, so that the contribution of voids in resin composite to stress relief could be investigated. Experiments were carried out on 200-um-thick layers of resin bonded from wall to wall in a restrained condition. The resin samples were divided into three groups: Group A was without porosity, group B contained a small number of pores, and group C contained a large number of pores in comparison with group B. For each group, porosity area, maximal stress, and stress development rate were determined. The mean maximal stress and stress development rate were inversely proportional to the mean porosity surface. These characteristics differed significantly (p < 0.01) between group A and C. For determination of whether shrinkage stress reduction has to be ascribed to flow from the outer surfaces of the voids or to inhibition of the setting reaction by oxygen in the voids, resin containing only nitrogen bubbles was also tested. The results indicated that both aspects contributed substantially to shrinkage stress relief. Incorporation of pores by the stirring of a luting cement contributes to stress reduction and can therefore be considered as a contribution to the maintenance of marginal integrity.
Effects of Cement-curing Modes on Dentin Bonding of Inlays
Authors: Zuellig-Singer R. , Krejci I. , Lutz F. 
Published: November 2010

The aim of this in vitro study was to evaluate dentin adhesion after cementation of immediate direct "All Purpose" Hybrid (AP.H) composite inlays (Dentsply) and Cerec Dicor-MGC (Dentsply) inlays with the dentin adhesive Prisma Universal Bond 2 (Dentsply) and the dual-curing Dicor-MGC luting composite (Dentsply). In 24 extracted human molars, standard MOD cavities were prepared with one approximal margin located in enamel and the other one located in dentin. They were divided into four groups: (I) AP.H inlays, luting composite only, chemically cured; (II) AP.H inlays, luting composite, immediately-light-cured; (III) AP.H inlays, luting composite, initially chemically and delayed-light-cured (15 min); and (IV) MGC inlays, luting composite, initially chemically and delayed-light-cured (15 min). In vitro load cycles corresponding to five years of clinical stress followed. Initially and after specimens were loaded, the margins were analyzed quantitatively by SEM. The tooth/cement and cement/inlay interfaces were scored separately. The initial percentages of "continuous margin"—at both the tooth/luting composite and luting composite/inlay interfaces-were higher than 94% for all groups. At the end of the load cycles, the quality of the margins at the tooth/luting composite interface significantly decreased for all groups. The highest decrease was found for the cervical margins located in dentin, where only 37%-61% were scored as "continuous margin". The AP.H inlay/luting composite interface showed almost no change. At the MGC inlay/ luting composite interface, the percentage of "continuous margin" decreased to 74%. After specimens were loaded, the percentage of "continuous margin" in dentin was lower than in enamel, despite the use of a dentin bonding agent (PUB 2). Chemical curing alone and immediate- and delayed-light-curing modes of the dual-cured luting composite showed "continuous margin" scorings which were not statistically different from each other.
Association Between Salivary Flow Rate and the Use of Systemic Medication Among 76-, 81-, and 86-year-old Inhabitants in Helsinki, Finland
Authors: Narhi T.O. , Meurman J.H. , Ainamo A. , Nevalainen J.M. , Schmidt-Kaunisaho K.G. , Siukosaari P. , Valvanne J. , Erkinjuntti T. , Tilvis R. , Makila E. 
Published: November 2010

The aim of this study was to examine salivary flow rate and its association with the use of medication in a representative sample of 76-, 81-, and 86-year-old subjects, totaling 368. In this study, 23% (n = 80) of the subjects were unmedicated. From one to three daily medications were used by 47% (n = 168) and more than four medications by 30% (n = 104). The most commonly used medications were nitrates, digitalis or anti-arrhythmic drugs (47.7%), analgesics and antipyretics (32.6%), and diuretics (29.5%). The mean number used daily was significantly higher in 86-year-olds than in the two younger age groups (p < 0.01). No significant differences in this respect were found between genders. Among the unmedicated subjects, 76-year-olds had significantly higher stimulated salivary flow rates than did the 81-year-olds (p < 0.05). Unmedicated women showed significantly lower unstimulated (p < 0.01) and stimulated flow rates than did men (p < 0.05). Stimulated salivary flow rate was also significantly higher in the 76-year-old medicated subjects than in the medicated 86-year-old subjects (p < 0.05). No statistically significant differences were found in unstimulated salivary flow rates among the three age groups. Medicated women showed significantly lower unstimulated salivary flow rates than men (p < 0.001), although the difference in stimulated saliva flow was not significant. A statistically significant difference in unstimulated and stimulated salivary flow rates was found between unmedicated persons and those who took from four to six, or more than seven, prescribed medications daily.
Immunocytochemical Localization of Cathepsin D in Rat Junctional Epithelium
Authors: Ayasaka N. , Goto T. , Tsukuba T. , Kido M.A. , Nagata E. , Kondo T. , Yamamoto K. , Tanaka T. 
Published: November 2010

Localization of cathepsin D was studied in the junctional epithelium (JE) of healthy rat gingivae by immuno-light and -electron microscopy, by means of both the avidin-biotin-peroxidase complex method and a colloidal gold IgG method. At the light-microscopic level, cathepsin D was demonstrated in the JE and oral sulcular epithelium (OSE). Cathepsin D immunoreactivity was remarkable in the coronal portion of the JE and decreased toward its apical portion. However, cathepsin D immunoreactivity in the basal cell layer of the JE was negligible or negative. In the OSE, the granular layer was positive for cathepsin D. In the adjacent connective tissue, many macrophage-like cells (not clear at this level) close to the basal cell layer showed strong immunoreactivity. At the electron microscopic level, cathepsin D was found in the primary lysosomes and trans-cisternae of Golgi apparatus in the JE cells. These lysosomes were often fused together or were fused with cathepsin D-negative intracytoplasmic vacuoles to form secondary lysosomes, which indicated that intracellular digestion may have been in progress. However, neutrophils contained few gold particles based on cathepsin D. It is likely that the amounts of cathepsin D contained in the JE cells and macrophages are larger than those of cathepsin D contained in the neutrophils. These findings provided morphological evidence that JE cells have the same endocytotic capacity as macrophages and neutrophils, and that JE cells participate in the intracellular digestion that is carried out by lysosomal enzymes such as cathepsin D. It is suggested, in addition, that maximum intracellular digestion occurs in the coronal portion of the JE.