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Biomedical subjects

William D Browning

Publications and source records attributed to William D Browning.

12 recordsLinked to original sources
PubMed2006

Performance of 2 packable composites at 12 months.

OBJECTIVE: The purpose of this randomized, double-blind, clinical trial was to compare the marginal seal of 2 packable resin composite materials in moderate to large lesions on molars. METHOD AND MATERIALS: Fifty participants in need of a moderate to large Class 2 or complex Class 1 molar restoration were randomly distributed into 4 groups, to receive either Alert (Jeneric/Pentron) or SureFil (Dentsply/Caulk) resin composite with or without a surface sealer. Each participant received one restoration. With the exception that study protocol limited increments to no more than 4 mm, teeth were restored according to the manufacturers' instructions, and surface sealer was applied after finishing in the designated groups. Use of Alert includes routine placement of a flowable composite liner. Clinical performance of the restorations was evaluated in 8 categories at baseline, 6 months, and 12 months. The 2 materials were compared to determine if a difference in marginal seal existed between groups. The number of restorations exhibiting marginal staining was compared using Fischer's exact test at a significance level of 5%. RESULTS: Six participants did not present for the 12-month recall. At 12 months, 19 (90.5%) Alert restorations and 15 (68.2%) SureFil restorations did not exhibit marginal staining. There was no statistically significant difference between the 2 restorative materials for marginal staining. Overall, 3 restorations were rated as failures. CONCLUSION: At 12 months, materials placed with a flowable liner were not associated with a significant reduction in marginal staining.

Adult↗
PubMed2006

The benefits of glass ionomer self-adhesive materials in restorative dentistry.

Bonded, resin-based composite restorative materials have potential advantages. If the dentin bond achieved is not greater than the polymerization stress, loss of retention is likely, resulting in areas of microleakage and postoperative sensitivity. Class 5 lesions restored with no preparation have been used for testing the clinical performance of new adhesive restorative systems. Laboratory studies have demonstrated that bond strength varies according to the depth of dentin and the degree of calcification. Until the later generations of dentin bonding agents, retention rates for bonded, resin-based composites were typically more erratic and lower than glass ionomer (GI) and resin-modified glass ionomer (RMGI) restorative materials. Providing stress relief during setting is inherent in GI and RMGI materials, which helps to explain their good retention rates, despite their low bond strengths. GI and RMGI liners and lightly filled resin bonding agents provide similar stress relief. Current evidence supports the use of both RMGI and composite restorations placed with a liner of lightly filled resin in adhesive Class 5 restorations. Bonded, resin-based composite has the advantage of finishing to a high-gloss surface, making it more acceptable in areas of the mouth that are highly visible.

Acrylic Resins↗
PubMed2006

Standardized method to produce tetracycline-stained human molar teeth in vitro.

OBJECTIVE: This study tested the hypothesis that exposure of human molar teeth to tetracycline (TCN) derivatives in vitro results in tooth discoloration resembling the clinical presentation of TCN staining. METHOD AND MATERIALS: The effects of exposure of 20 extracted human molar teeth to distilled water, chlortetracycline, doxycycline, or minocycline were compared. The baseline color of each tooth was analyzed with a dental spectrophotometer. The pulp chambers were each filled with a TCN derivative solution and then sealed. The teeth were placed in a centrifuge tube and then centrifuged at 2800 rpm for 20 minutes. Color change was monitored weekly for 7 weeks. Digital images of the surfaces were recorded. For each specimen at every evaluation period, color change from baseline was calculated using Commission Internationale d'Eclairage (CIE) Delta E 2000 (deltae00). RESULTS: There was a significant association between the type of derivative used and deltae00, as well as between the evaluation period and deltae00. There was also a significant association between the interaction term, derivative x evaluation period, and deltae00. Results of the Holm-Sidak post hoc test demonstrated that all 3 TCN derivatives were associated with significantly larger deltae00 than the control group (P < or = .05). CONCLUSIONS: All 3 TCN derivative solutions produced significant color changes as time progressed. Different TCN derivatives produced a different L* (lightness), C* (chroma), and H* (hue), with minocycline behaving distinctly differently from chlortetracycline and doxycycline. The model could be used to study the underlying mechanisms of TCN staining as well as many aspects of vital tooth

Analysis of Variance↗
PubMed2004

Blood pressure screening practices of a group of dental hygienists: a pilot study.

PURPOSE: Recent research suggests that one in five Americans has hypertension, according to the American Heart Association. When hypertension is undiagnosed or uncontrolled, it places patients at risk for other cardiovascular diseases, contributing to an increase in mortality. Dental hygienists are in an ideal setting to screen for this silent disease. This study was designed to determine how frequently a group of practicing dental hygienists performs screenings for hypertension on their patients, and to determine the barriers that prevent this screening from occurring. METHODS: One hundred one dental hygienists were questioned with a written survey about their blood pressure screening practices and their reasons for not taking blood pressure readings, if applicable. RESULTS: Sixty-seven dental hygienists completed the survey. Survey results revealed that the majority of dental hygienists were not recording blood pressure readings, even though their dental hygiene school curriculum had emphasized doing so for all patients. The most frequently cited reasons for not performing a routine blood pressure screening were insufficient time in the appointment and the minimal value given to the procedure by their employers. CONCLUSION: To work against obstacles that prevent the provision of this service, dental and dental hygiene faculty must increase their efforts to inculcate in their students the value of blood pressure screening. Further studies are needed to determine if the findings of this study are indicative of only one segment of dental hygiene practitioners, or if they represent the norm in the profession.

Blood Pressure Determination↗
PubMed2004

Safety and efficacy of a nightguard bleaching agent containing sodium fluoride and potassium nitrate.

OBJECTIVES: Transient sensitivity during bleaching is generally reported to affect 67% of patients. While most people tolerate this sensitivity, some find it impossible to continue treatment. The purpose of this study was to determine the safety and efficacy of an experimental, low-sensitivity bleaching agent. METHOD AND MATERIALS: Twenty-two participants bleached for a minimum of 6 hours per night over a 2-week period. The bleaching agent used, Experimental Product E, is a 10% carbamide peroxide gel containing potassium nitrate and sodium fluoride. Evaluations were performed at baseline and 1,2,13, and 26 weeks. Color change was measured using a value-ordered Vita classic shade guide and a colorimeter. Sensitivity of the teeth, gingiva, tongue, and/or throat was measured daily using a patient log. RESULTS: The median color change after 2 weeks was eight tabs. Approximately 36% reported sensitivity during the active whitening phase of the study. As a group, participants reported sensitivity during 13.7% of the total days spent whitening. CONCLUSION: Experimental Product E was shown to be safe. Participants experienced minor sensitivity during the active bleaching phase only. Experimental Product E was shown to be an effective bleaching agent for the subjects tested in this study.

Adult↗
PubMed2003

Clinical evaluation of a 3% hydrogen peroxide tooth-whitening gel.

PURPOSE: The purpose of this randomized double-blind investigation was to clinically evaluate the effectiveness of a commercially available 3% hydrogen peroxide tooth-whitening material (ADS Tooth Whitening Gel, Applied Dental Sciences, Inc., Lee, MA). The material was used over 2 weeks in a dentist-supervised, patient-applied application. MATERIALS AND METHODS: The evaluation was carried out in accordance with American Dental Association (ADA) Council on Scientific Affairs Acceptance Program Guidelines for Home-Use Tooth Whitening Products (May 1998). Sixty-five participants were randomized into two groups (active and placebo) for a double-blind, placebo-controlled study. A custom application tray, scalloped without reservoirs, was fabricated for each participant. Tooth shades were documented by matching with the Vita shade guide ordered according to value and assigned a numeric ranking from 1 to 16, darkest to lightest. Participants were supplied with the treatment solutions to use in the application tray. Duration of active treatment was 30 minutes 3 times a day for 2 weeks. Participants were evaluated at baseline, 1 week and 2 weeks treatment, and 12 and 26 weeks post-treatment. The statistical analysis used at each time point to determine the difference between the active and placebo groups based on the change in value was the two-sample t-test. Plaque and soft tissue indices were also recorded. RESULTS: The teeth treated with 3% hydrogen peroxide were significantly lighter at 2, 12, and 26 weeks (p < or = .0140, .0004, and .0001, respectively) compared with the placebo group. The mean shade change was 4.2 Vita shade tabs at 2 weeks. At 26 weeks (6 months), the degree of whitening was 4.1 tabs.

Adult↗
PubMed2003

Use of shade guides for color measurement in tooth-bleaching studies.

UNLABELLED: Several different methods are used to measure tooth color in bleaching studies. The ADA Acceptance Program Guidelines for Home Use Tooth Whitening Products specify the use of a value-oriented shade guide and/or electronic color measurement devices. Since people perceive color differently, shade guides are a subjective measure. Differences between raters and by the same rater are well documented in the dental literature. The purposes of this article will be to discuss the advantages and disadvantages using shade guides to measure color change related to tooth whitening, and to evaluate the correlation of data gathered from the use of shade guides to electronic color measurement devices. Using an order published by the manufacturer, both the TRUBYTE Bioform and Vita Classical guides can be arranged by value. A study by O'Brien demonstrated however, that the order is flawed and the change in brightness from tab to tab varies greatly. Despite these disadvantages, a review of data from several clinical trials demonstrates that Vita Classical shade guide data is consistent with data gathered using electronic color measurements. Furthermore, the O'Brien data can be used to make both these guides better measurement systems. The ADA Certification program standards define the degree of overall color change that should be considered clinically important. This issue is as critical as the measurement system used. Reporting color changes that are neither detectable to the human eye nor considered by the public to be important offers the profession little usable information. Given that any standard for color change during bleaching must relate to the abilities of the human eye, it is the conclusion of the author that shade guides should remain a critical element of any bleaching study. CLINICAL SIGNIFICANCE: Clinicians are frequently exposed to reports of bleaching agents that have been shown to result in a change of 6, 7, 8, etc., tabs. Without understanding the limitations of the shade guide used, reports of a specific shade tab change are of little use and may actually be misleading.

Color↗
PubMed2002

Sensitivity and tooth whitening agents.

PURPOSE: Three commercially available dentist-prescribed home-applied bleaching systems were evaluated to identify the incidence of sensitivity and to compare the efficacy of whitening the maxillary anterior teeth of 18 patients. METHODS: NiteWhite Excel 2Z (Discus Dental), fx (Challenge Products), and Rembrandt Xtra-Comfort (DenMat Corp.) were randomly assigned to six patients each. The fx product was used as a control since it was not advertised as a zero sensitivity product. The manufacturers' instructions for tray fabrication and use were followed while the patients bleached for 2 weeks. The patients kept a diary and were recalled at 1 week, 2 weeks, and 4 weeks. The shade change and the presence or absence of any sensitivity were evaluated at each recall. RESULTS: NiteWhite Excel 2Z was used for 83 days of treatment with the following percentage of positive sensitivity reported: 0% hot and cold, 2.4% throat sensitivity, 2.4% tongue sensitivity, and 25.3% gingival sensitivity. Rembrandt Xtra-Comfort was used for 84 days with 0% hot and cold, 0% throat, 11.9% tongue, and 27.4% gingival sensitivity reported. The fx product was used for 83 days and resulted in 14.5% hot and cold, 3.6% throat, 1.2% tongue, and 16.9% gingival sensitivity. All products lightened the teeth an average of eight shade tabs on the Vita guide. There was a statistically significant difference between the groups when comparing the presence of sensitivity (chi-squared test, p < .001) but not when comparing the shade tab change. CLINICAL SIGNIFICANCE: Of the products tested, all produced similar change in shade tab value, none were sensitivity free, but NiteWhite Excel 2Z and Rembrandt Xtra-Comfort did not produce thermal sensitivity.

Carbamide Peroxide↗
PubMed2002

Comparison of luting cements for minimally retentive crown preparations.

OBJECTIVE: The purpose of this study was to compare the retentive strengths of resin, glass-ionomer, and zinc phosphate cements under adverse conditions. METHOD AND MATERIALS: Thirty extracted teeth were mounted and prepared in their long axis. The axial wall height was 3 mm and the convergence angle was 28 degrees. These conditions increased the role of the cement and decreased the role of the preparation in providing retention of the casting. The axial surface area was determined. Copings were fabricated with a ring aligned in the long axis to facilitate removal of the crown. They were cemented with a resin cement, a glass-ionomer cement, or a zinc phosphate cement. A block randomization scheme was used to assign cements so that the mean surface areas of the teeth were equivalent in all groups. The copings were loaded in tension, and the amount of force required to remove the coping was recorded. The stress required to remove the coping was calculated. RESULTS: The mean stress required to remove the copings was 9.4, 5.0, and 3.1 MPa for the resin, glass-ionomer, and zinc phosphate cements, respectively. CONCLUSION: The resin cement group was significantly stronger than both the glass-ionomer cement and the zinc phosphate cement groups. The glass-ionomer cement was significantly stronger than the zinc phosphate cement.

Analysis of Variance↗
PubMed2002

Predictors of success in dental hygiene education: a six-year review.

The purpose of this study was to examine the predictive reliability of incoming grade point average (GPA), incoming math/science GPA, and Scholastic Aptitude Test (SAT) scores in predicting success in dental hygiene education. Success in dental hygiene education was defined in terms of Dental Hygiene National Board score (N-BRD) and dental hygiene GPA at graduation (DH-GPA). Academic transcripts and admissions documents of 134 students comprising the Medical College of Georgia dental hygiene classes of 1996-2001 were reviewed. Incoming college GPA (1-GPA), incoming college math/science GPA (MS-GPA), total SAT score (T-SAT), verbal SAT score (V-SAT), math SAT score (M-SAT), N-BRD score, and DH-GPA were documented for each student. A forward, step-wise, multiple linear regression was used to analyze the data. I-GPA was the most significant predictor of success. Analysis showed that DH-GPA was best predicted by both the I-GPA (p < or = .001) and T-SAT (p < or = .004). Only the I-GPA (p < or = .001) was significant in predicting N-BRD scores. Data from this study will be used to evaluate the admissions process in dental hygiene at the Medical College of Georgia.

Achievement↗
PubMedDate not supplied

Predictors of non-carious loss of cervical tooth tissues.

This Predictor Variables study is designed to determine which one of 11 factors evaluated may be correlated to Non-carious Loss of Cervical Tooth Tissues (NLCTT) using subjects with and without NLCTT. The ultimate objective is to successfully predict the path toward risky behaviors and reduce the incidence of NLCTT.

Acids↗