PubMed Health⌕ Search

Biomedical subjects

K B Frazier

Publications and source records attributed to K B Frazier.

17 recordsLinked to original sources
PubMed2001

Tray delivery of potassium nitrate-fluoride to reduce bleaching sensitivity.

OBJECTIVE: Tooth sensitivity is a common side effect associated with tooth whitening. The purpose of this study was to determine if bleaching tray delivery of potassium nitrate-fluoride reduces bleaching sensitivity enough to allow continuation of whitening treatment. METHOD AND MATERIALS: Thirty patients were enrolled in a university-approved clinical study and had their teeth bleached at night with 10% carbamide peroxide in a custom-fitted tray. The bleaching tray was a rigid experimental design for which sensitivity was expected. If tooth sensitivity was experienced, the patient applied a gel containing 5% potassium nitrate and 1,000 ppm sodium fluoride in the bleaching tray for various time periods. Log forms were collected upon completion of bleaching, and patient interviews were used to compare effects of the gel before and after sensitivity treatment. RESULTS: Sixteen out of 30 patients experienced tooth sensitivity. Of those 16 patients, 12 used the gel, and 11 of the 12 reported a reduction in sensitivity. Treatment times ranged from 10 minutes before bleaching to 30 minutes before and after. The number of applications ranged from one to continuous use. Some patients were able to continue bleaching after one gel application with no subsequent sensitivity. Other patients were unable to continue bleaching unless they continued using the gel. The incidence of tooth sensitivity (53%) reported in this study is consistent with sensitivity reported in studies using semi-rigid custom-fitted trays made from stone casts with a nonscalloped, nonreservoir design. CONCLUSION: The use of a 5% potassium nitrate-fluoride gel applied in the tray as needed for tooth sensitivity associated with nightguard vital bleaching can reduce sensitivity in a majority of patients and allow most patients to continue bleaching to completion.

Carbamide Peroxide↗
PubMed2000

Dependence of plasma alpha-tocopherol flux on very low-density triglyceride clearance in humans.

To evaluate the effect of dietary fat-induced alterations in triglyceride (TG) metabolism on plasma and very low-density lipoprotein (VLDL)-alpha-tocopherol, nine healthy males (mean +/- SEM, age: 36 +/- 3 years, BMI: 24.7 +/- 1.1) consumed a 35%-fat diet (control) for one week followed by a 15% low-fat, high-carbohydrate diet for 5 weeks. After each dietary phase, the subjects ingested an evening meal along with a 50 mg capsule of (2)H(6)-RRR-alpha-tocopheryl acetate; blood samples were drawn over a 24 h period while the subjects remained fasted. Low-fat feeding increased fasting plasma TG concentrations by 53% (116 +/- 27 to 178 +/- 32, mg/dl, p < 0.0001) primarily by reducing VLDL-TG clearance. Total plasma alpha-tocopherol concentrations (labeled + unlabeled) were unchanged (25.8 +/- 2.3 vs. 26.4 +/- 3.0 nmol/ml plasma) and no differences between the diets were observed for plasma (2)H(6)-alpha-tocopherol concentration (4.8 +/- 0.6 nmol/ml, for both diets) or enrichments (18.1 +/- 1.8% average for both diets). However, low-fat feeding significantly increased the amount of alpha-tocopherol in the VLDL fraction (43%, p = 0.04) in concert with elevations in VLDL-apoB and TG. The alpha-tocopherol and TG content of VLDL varied in parallel in individual subjects and fractional replacement rates and clearance of alpha-tocopherol and TG in VLDL were closely correlated. Kinetic parameters were decreased by 32-39% from high-fat to low-fat. These data suggest that vitamin E bioavailability is similar between a 15 and 35% fat diet, with a redistribution of alpha-tocopherol in lipoproteins occurring during low-fat feeding (increased in the VLDL fraction, reduced in the other lipoproteins), and transfer of alpha-tocopherol from VLDL depends upon TG removal from the particle, consistent with previous observations in vitro and in animal studies.

Adult↗
PubMed2000

A case report of subpontic osseous hyperplasia in the maxillary arch.

Subpontic osseous hyperplasia has been portrayed in both the historical and the current literature as occurring exclusively in the mandibular posterior region. This article presents the clinical, radiologic, and microscopic documentation of subpontic osseous hyperplasia occurring in the maxillary first molar region.

Aged↗
PubMed2000

Teaching nightguard bleaching and other tooth-whitening procedures in North American dental schools.

Tooth-whitening using carbamide peroxide delivered in a custom-fitted tray (nightguard bleaching) is a relatively new procedure, yet it is currently one of the most commonly used types of esthetic dental treatment in private practice. This study determined the extent that nightguard bleaching (NGB) has been included in dental school curricula. All sixty-five dental schools in North America were surveyed about curriculum content and treatment protocol for the use of nightguard and other bleaching procedures, generating an 82 percent response. The survey covered eighteen subject areas related to NGB ranging from clinical requirements and indications to products and recall intervals used. The most commonly taught tooth-whitening procedure was NGB, which was most often taught by operative and restorative faculty. Although no schools had clinical requirements for NGB, 92 percent taught it. The most common indications for NGB were esthetic shade change and pre-restorative lightening of teeth. Unrestored caries, defective restorations, and pre-existing sensitivity were common contraindications. Most schools do not use a specific NGB consent form, but most use written patient instructions. Most schools use at least two different NGB products, bleach for two to four weeks, and use reservoired and scalloped trays. An average of 25 percent of NGB patients were estimated to develop sensitivity, for which treatment recommendations include fluoride, desensitizing toothpaste, and reduced exposure time. Curriculum time and safety concerns were reasons for not teaching NGB (8 percent schools). Most schools indicated that the relative importance of NGB in the curriculum was increasing.

Canada↗
PubMed1999

Effect of toothbrushing on elemental release from dental casting alloys.

PURPOSE: This study assessed the effect of toothbrushing on the elemental release from common dental casting alloys. MATERIALS AND METHODS: A Au-Pt high-noble alloy, a Au-Pd high-noble alloy, a Pd-Cu-Ga noble alloy, and a Ni-Cr base-metal alloy were placed into a biological medium for 1 week to allow equilibration of elemental release, then brushed for 30 minutes at 90 strokes/min under 200 g of force with a soft toothbrush. The brushing was performed in neutral saline or lactic acid at pH 4 with or without toothpaste. The alloys were then transferred back into a biological medium for 1 week. Atomic absorption spectroscopy was used to measure the mass lost from each alloy during and in the week after brushing. Mass loss was expressed as micrograms per square centimeter of alloy surface, and the various brushing conditions were compared by analysis of variance and Tukey multiple comparison intervals (alpha = 0.05). RESULTS: During brushing, element release increased significantly over nonbrushed controls for all alloys except the Ni-Cr. Toothpastes, acidic solutions, or combinations of these conditions with toothbrushing further enhanced elemental release, but Ni release from the Ni-Cr alloy increased the most (30-fold). In the week after brushing, brushing alone increased elemental release only from the Ni-Cr alloy. However, toothpastes and acidic solutions increased elemental release for all alloys significantly, except for the Au-Pd alloy. In general, elemental release during brushing was far greater than in the week after brushing. CONCLUSIONS: Under the conditions of this study, toothbrushing increased the elemental release from dental casting alloys.

Analysis of Variance↗
PubMed1999

Carbamide peroxide whitening of nonvital single discolored teeth: case reports.

Patients who present with a single discolored tooth represent a significant restorative challenge. These case reports describe an economic and conservative treatment option for these patients. The situations presented demonstrate techniques for bleaching with carbamide peroxide in a traditional nightguard or with an inside-outside technique to achieve acceptable esthetic results on isolated nonvital discolored teeth. Although these techniques may not be effective in all cases, they do not compromise or eliminate any future treatment options.

Adult↗
PubMed1998

Comparison of wear-resistance of Class V restorative materials.

Compomers and resin-modified glass ionomers have been developed to improve the physical properties of traditional glass ionomer cements. This project compared the toothbrush wear-resistance of three compomers (Compoglass, Dyract, Hytac) and three resin-modified glass ionomer restorative materials (Fuji II LC, Photac-Fil, Vitremer) to that of two resin-based composites (Herculite XRV, Silux Plus). Specimens (n = 7) were prepared according to manufacturers' instructions and stored in a humidor for 48 hours prior to testing. The specimens were subjected to 120,000 strokes at 1.5 Hz, using a brush-head force of 200 g on a Manly V-8 cross-brushing machine. The slurry contained a 50:50 (w/w) mixture of toothpaste and deionized water. Abrasion-resistance was calculated by measuring specimen mass-loss prior to and subsequent to brushing. The data were analyzed using a one-way analysis of variance (ANOVA) and the Tukey-Kramer post-hoc test. Significant differences (p < .0001) in mass-loss were found, and loss ranged from 0.013 +/- 0.003 g (Hytac) to 0.061 +/- 0.009 g (Compoglass). No correlation (p = .959) between wear-resistance and experimentally determined filler content existed. This study showed that all but one hybrid resin-ionomer type material exhibited a resistance to toothbrush wear that was as good as or better than that of the two traditional resin-based composite materials.

Analysis of Variance↗
PubMed1998

Nightguard bleaching to lighten a restored, nonvital discolored tooth.

Traditional techniques to lighten discolored endodontically treated teeth have used bleaching materials that had to be applied and directly monitored by dentists. These bleaching techniques have been associated with cervical resorption in nonvital teeth, and the treatment outcome is often difficult to predict. This article describes the use of nightguard bleaching to obtain an esthetic result for a restored nonvital tooth that had been treated with limited success with traditional office-based bleaching procedures.

Adult↗
PubMed1997

The teaching of all-ceramic restorations in North American dental schools: materials and techniques employed.

North American dental schools were surveyed to determine the types of clinical experiences and the extent of material use that predoctoral students encounter with restorative procedures that employ all-ceramic materials. The results were based on an overall response rate of 80% from the 64 surveyed schools. The majority (96%) of the 51 schools responding to the survey did offer an opportunity to become experienced with all-ceramic restorations. The selection of bases and liners for all-ceramic restorations included dentin adhesive agents, glass ionomer materials, and calcium hydroxide products, by a ratio of 5:4:1, respectively. The most commonly used impression material types were addition silicone and polyether. One or both of these materials were used by every school. Dicor glass ceramic and alumina core ceramic were the most commonly used materials by the responding schools for veneers, onlays, and crowns. Dicor glass ceramic and CAD/CAM ceramic were most commonly used for inlays. Crowns were made of more different all-ceramic material types than the other restoration classes. Fabrication of all-ceramic restorations was primarily by commercial laboratories and school technicians. Students have hands-on experience in the fabrication of all-ceramic restorations in 6% of the responding schools. Luting agents for all-ceramic restorations include dual-cured resin, in 96% of the responding schools, light-cured resin, 43%, and glass ionomer cement, 33%. Zinc phosphate, chemical-cured composite, and polycarboxylate were used by less than one fourth of the respondents. Only resin-based composite materials were used to lute ceramic veneers. Rubber dam was applied primarily during luting procedures involving all-ceramic inlays and onlays. Crowns and veneers were isolated by this method in less than 30% of the responding schools. Finishing procedures with all-ceramic restorations were accomplished with three or more instruments by 89% of the schools.

Ceramics↗
PubMed1996

The teaching of all-ceramic restorations in North American dental schools: curricular requirements and indications.

A survey was conducted to examine the manner in which North American dental school curricula provide instruction to pre-doctoral students in the applications of all-ceramic restorative materials. A questionnaire was sent to all 64 dental schools and the response rate was 80%. All dental schools offered didactic instruction, and 96% also provided some clinical experience. Most of the time, two departments are involved in teaching this clinical subject, with fixed prosthodontics being the department most frequently cited. Veneers were the most commonly taught all-ceramic restoration. Crowns were most frequently used on anterior teeth and premolars, especially in the maxillary arch. Inlays were almost exclusively performed for class I and class II lesions, whereas onlays were considered when the isthmus width of an inlay preparation exceeded one half of the intercuspal distance. Contraindications for the use of these materials were listed, with occlusal dysfunction such as bruxism being the most commonly cited reason for not using all-ceramic materials. The primary reasons for not teaching these procedures included insufficient longitudinal research and the lack of in-house laboratory support. Most schools indicated that the relative importance of all-ceramic restorations as a component of their curriculum was increasing.

Ceramics↗
PubMed1996

The teaching of all-ceramic restorations in Scandinavian dental schools: a survey.

The study was designed to survey the curricular requirements, types of clinical experience, and materials/ techniques used in teaching programs for all-ceramic restorations in Scandinavian dental schools. All 13 dental schools responded. Ten offered some clinical experience to pre-doctoral students, but only one required one all-ceramic restoration. The departments of fixed prosthodontics had the main teaching responsibility. All-ceramic crowns were taught at 9, veneers at 7, and inlays/onlays at 10 dental schools. A wide range of different teaching concepts, materials, and views on indications and contraindications was reported. It appears as if all-ceramic restorations are regarded as experimental by the teaching institutions, although the dental industry and some practitioners strongly recommend these types of restorations.

Ceramics↗
PubMed1995

Wear resistance of dual-cured resin luting agents.

PURPOSE: To evaluate the three-body wear resistance of five commercially available dual-cured resin-based composite luting agents compared both in a dry state and after water storage. MATERIALS AND METHODS: Six specimens of each material were prepared and tested for three-body wear resistance in the ACTA wear machine for 250,000 cycles and the loss of material was measured with a profilometer. Material wear was measured under three conditions: dry storage, 6-month water storage, and 12-month water storage. RESULTS: One-way and two-way ANOVA and Tukey's HSD test of multiple comparisons revealed significant differences in wear resistance. Water storage did not significantly affect the wear resistance of four of the five materials. The order of wear resistance was: Cosmedent Insure > Vivadent Dual-Cement > Kerr Porcelite Dual Cure > Jeneric/Pentron Optec Luting Cement > Chameleon Mirage FLC (P < or = 0.0001). The rank order of wear resistance could not be readily predicted when based solely on the manufacturers' reported physical specification data.

Acrylic Resins↗
PubMedDate not supplied

Effect of prophylactic polishing protocols on the surface roughness of esthetic restorative materials.

Many polishing protocols have been evaluated in vitro for their effect on the surface roughness of restorative materials. These results have been useful in establishing protocols for in vivo application. However, limited research has focused on the subsequent care and maintenance of esthetic restorations following their placement. This investigation evaluated the effect of five polishing protocols that could be implemented at recall on the surface roughness of five direct esthetic restorative materials. Specimens (n=25) measuring 8 mm diameter x 3 mm thick were fabricated in an acrylic mold using five light-cured resin-based materials (hybrid composite, microfilled composite, packable composite, compomer and resin-modified glass ionomer). After photopolymerization, all specimens were polished with Sof-Lex Disks to produce an initial (baseline) surface finish. All specimens were then polished with one of five prophylactic protocols (Butler medium paste, Butler coarse paste, OneGloss, SuperBuff or OneGloss & SuperBuff). The average surface roughness of each treated specimen was determined from three measurements with a profilometer (Surface 1). Next, all specimens were brushed 60,000 times at 1.5 Hz using a brush-head force of 2 N on a Manly V-8 cross-brushing machine in a 50:50 (w/w) slurry of toothpaste and water. The surface roughness of each specimen was measured after brushing (Surface 2) followed by re-polishing with one of five protocols, then final surface roughness values were determined (Surface 3). The data were analyzed using repeated measures ANOVA. Significant differences (p=0.05) in surface roughness were observed among restorative materials and polishing protocols. The microfilled and hybrid resin composite yielded significantly rougher surfaces than the other three materials following tooth brushing. Prophylactic polishing protocols can be used to restore a smooth surface on resin-based esthetic restorative materials following simulated tooth brushing.

Analysis of Variance↗