Biomedical subjects

Ralph H Leonard

Publications and source records attributed to Ralph H Leonard.

7 recordsLinked to original sources

PubMed2005

Effect on enamel microhardness of two consumer-available bleaching solutions when compared with a dentist-prescribed, home-applied bleaching solution and a control.

BACKGROUND: There exists limited data in the literature regarding the efficacy and safety of consumer-available, paint-on bleaching solutions. PURPOSE: The purpose of this in vitro study was to evaluate the effect of two consumer-available, paint-on bleaching products on enamel microhardness against a control and a dentist-prescribed, home-applied (DPHA) bleaching product. MATERIALS AND METHODS: Eighty enamel slabs were obtained from extracted human teeth and randomly divided into four treatment groups: (1) control; (2) Opalescence (Ultradent Products, Inc., South Jordan, UT, USA); (3) Crest Night Effects (Procter & Gamble, Cincinnati, OH, USA); and (4) Colgate Simply White Night (Colgate-Palmolive Co., Piscataway, NJ, USA). Opalescence is a carbamide peroxide DPHA product, whereas Crest Night Effects and Colgate Simply White Night are consumer-available products. The specimens in groups 2 to 4 underwent 2 weeks of treatment for 8 h/d. Specimens were maintained in artificial saliva at 37 degrees C between treatments. Subsequently, one-half of the specimens in groups 2 to 4 (n=10) underwent an additional seven treatments for 8 h/d, while the other half were stored in artificial saliva, receiving no further treatment. Microhardness was measured as Knoop hardness numbers (KHNs) at baseline and after 1, 7, 14, and 21 treatment days. The results were analyzed for statistical significance both intra- and intergroups using analysis of variance (p=.05). RESULTS: A statistically significant reduction in mean KHN was observed compared with baseline at 1, 7, 14, and 21 treatment days for group 4 and at 7 treatment days for group 3. When compared with the control or DPHA product, group 4 was the only treatment that resulted in significantly lower mean KHNs at 7, 14, and 21 treatment days. CONCLUSION: When evaluating enamel microhardness, consumer available, paint-on bleaching solutions may adversely affect enamel microhardness compared to a control and 10% carbamide peroxide DPHA bleaching solution. CLINICAL SIGNIFICANCE: With numerous consumer-available bleaching products on the market, it is crucial to be judicious in their selection and use. The results of this in vitro study showed that the consumer-available, paint-on bleaching solutions adversely affected enamel microhardness at some time during the study. Consumers should be made aware of this effect on enamel.

Carbamide Peroxide↗

PubMed2004

Desensitizing agent efficacy during whitening in an at-risk population.

BACKGROUND: Nightguard vital bleaching (NGVB) has gained acceptance among dentists and patients as a simple and effective procedure to lighten discolored teeth. Although the efficacy and predictability of NGVB have been well established, it has been documented that patients undergoing the procedure may experience side effects such as tooth sensitivity (TS) and gingival irritation (GI). A previous NGVB study suggested that selected participants might benefit from a regimen of a desensitizing agent (DSA) to decrease or prevent TS during whitening. PURPOSE: The purpose of this study was to determine whether the daily use of an active DSA (UltraEZ, Ultradent Products Inc., South Jordan, UT, USA) during NGVB would decrease TS in a population at risk for TS when compared with a placebo. MATERIALS AND METHODS: Forty subjects participated in this single-blind randomized clinical trial. All participants had indicated that they had preexisting TS or other risk factors for TS during NGVB. To evaluate TS caused by the tray alone, participants wore custom-fitted maxillary whitening trays containing no DSA or whitening solution during week 1. Next, participants were randomly assigned to apply either the active DSA or placebo daily for 14 days in the trays for 30 minutes prior to whitening. The placebo was the same formulation as UltraEZ but without the desensitizing agents (3% potassium nitrate and 0.11% by weight fluoride ion). The bleaching solution was a 10% carbamide peroxide whitening solution (Opalescence, Ultradent Inc.). Post treatment, participants were followed up for 1 week, during which time they used neither trays nor solutions. Throughout the study, participants completed a daily diary to record their perceptions of TS and the time spent wearing the tray with the whitening solution. RESULTS: Forty-one percent of the active group had at least 1 day of TS during treatment compared with 78% of the placebo group. The difference was statistically significant (p = .027) using the two-tailed Fisher exact test. CLINICAL SIGNIFICANCE: This study suggests that the use of an active 3% potassium nitrate and 0.11% fluoride desensitizing agent for 30 minutes prior to whitening may decrease tooth sensitivity when compared with a placebo in a population at risk for tooth sensitivity.

Administration, Topical↗

PubMed2004

Effect of tray-based and trayless tooth whitening systems on microhardness of enamel surface and subsurface.

PURPOSE: To evaluate the effect of tray-based and trayless tooth whitening systems on surface and subsurface microhardness of human enamel. METHODS: Enamel slabs were obtained from recently extracted human third molars. Specimens were randomly assigned to six groups according to tooth whitening treatment (n = 10): 6.0% hydrogen peroxide (HP) (Crest Whitestrips), 6.5% HP (Crest Professional Whitestrips), 7.5% HP (Day White Excel 3), 9.5% HP (Day White Excel 3), 10% carbamide peroxide (Opalescence), and a control group (untreated). Specimens were treated for 14 days following manufacturers' recommended protocols, and were immersed in artificial saliva between treatments. Enamel surface Knoop microhardness (KHN) was measured immediately before treatment, and at days 1, 7, and 14 of treatment. After treatment, subsurface microhardness was measured at depths of 50-500 microm. Data were analyzed for statistical significance using analysis of variance. RESULTS: Differences in microhardness for treated vs. untreated enamel surface were not statistically significant at any time interval. For 6.5% and 9.5% HP, there was a decrease in surface microhardness values during treatment, but at the end of treatment the microhardness values were not statistically different from the baseline values. For the enamel subsurface values, no differences were observed between treated vs. untreated specimens at each depth. Trayless and tray-based tooth whitening treatments do not significantly affect surface or subsurface enamel microhardness.

Carbamide Peroxide↗

PubMed2003

Nightguard vital bleaching of tetracycline-stained teeth: 90 months post treatment.

PURPOSE: The purpose of this longitudinal whitening study was to determine the stability, post-treatment side effects, and patient satisfaction at 90 months post treatment after 6 months of active treatment of tetracycline-stained teeth with 10% carbamide peroxide. MATERIALS AND METHODS: Fifteen of 21 participants enrolled in the study (71%) were contacted and asked to participate in a survey concerning their whitening experience. Participants were asked whether there had been any change in the shade of their teeth after treatment and if they had experienced any side effects that they believed were treatment related. Eight of the 15 participated in a clinical examination. RESULTS: Nine participants (60%) reported no obvious shade change or only a slight darkening not noticed by others. None reported darkening back to the original shade; however, four had re-treated their teeth. Examiners were in agreement with the participants' perception of shade change upon comparing pretreatment and post-treatment photographs and Vita shade (Vita Zahnfabrik D-79713, Bad Sackingen, Germany) values. The degree of improvement over the pretreatment shade was significant for the 90-month post-treatment shade (p < .01). All respondents (n = 15) denied having to have a crown or root canal or tooth sensitivity that they believed was treatment related. CLINICAL SIGNIFICANCE: The results of this study of nightguard vital bleaching indicate that tetracycline-stained teeth can be whitened successfully using extended treatment time and that shade stability may last at least 90 months post treatment (range 84-100 mo). Patients participating in this study were over-whelmingly positive about the procedure in terms of shade retention and lack of post-treatment side effects.

Adult↗

PubMed2003

Long-term treatment results with nightguard vital bleaching.

Since its introduction into dentistry in 1989, nightguard vital bleaching has been proven to be a simple and safe procedure to lighten discolored teeth. Efficacy of the technique is 98% for nontetracycline-stained teeth, and with extended treatment time, tetracycline-stained teeth can be expected to lighten in at least 86% of cases. Satisfactory retention of the shade change without re-treatment can be expected in at least 43% at 10 years posttreatment. Side effects are usually mild and transient, disappearing within days of treatment completion with no long-term sequelae. Participants report that they are glad they went through the procedure, and wild recommend the procedure to a friend.

Humans↗

PubMed2002

Safety issues when using a 16% carbamide peroxide whitening solution.

BACKGROUND: The scientific literature is lacking on the occurrence of side effects and other safety issues when using carbamide peroxide whitening solutions of concentrations greater than 10%. This double-blind nightguard vital bleaching study compares safety issues when using 16% carbamide peroxide against a placebo or 10% carbamide peroxide (Nite White Classic by Discus Dental Inc.). Evaluated were changes in gingival index, plaque index, nonmarginal gingival index, nongingival oral mucosal index, tooth vitality, and the patients' perceptions of tooth sensitivity and gingival irritation. MATERIALS AND METHODS: Twenty female dental hygiene students participated in the study. Each participant wore a maxillary treatment tray for 1 week without any solution and then for 8 to 10 hours per night for 14 nights, filling each quadrant with placebo, 10% carbamide peroxide, or 16% carbamide peroxide, using a split tray design. RESULTS: With respect to gingival index, plaque index, nonmarginal gingival index, nongingival oral mucosa index, tooth vitality, and tooth sensitivity, there were no statistically significant differences between the 16% carbamide peroxide solution and the other two solutions (p > .05). Quadrants receiving the 16% carbamide peroxide solution experienced more gingival irritation than quadrants receiving placebo or 10% carbamide peroxide solution (p > .05). CONCLUSIONS: When evaluating the above-mentioned safety issues, except for gingival irritation, there were no statistically significant differences between a 16% carbamide peroxide solution and 10% carbamide peroxide solution or a placebo when used as described here. CLINICAL SIGNIFICANCE: Among the 20 participants whose data were analyzed, it was found that a 16% carbamide peroxide whitening solution (Nite White Classic), when used as described in this study, can be effective in nightguard vital bleaching with no statistical differences in gingival index, plaque index, nonmarginal gingival index, nongingival oral mucosa changes, tooth vitality, or tooth sensitivity, compared with a 10% whitening solution (Nite White Classic). More gingival irritation was experienced with 16% carbamide peroxide. Additionally, 20% of the participants in this study self-reported sensitivity when wearing their treatment tray without any solution, and 36% of the participants reported sensitivity to the placebo solution.

Adult↗

PubMed2002

Safety and stability of nightguard vital bleaching: 9 to 12 years post-treatment.

PURPOSE: The purposes of this retrospective case series study were to evaluate safety issues and determine participants' perceptions of a nightguard vital bleaching (NGVB) technique approximately 10 years post-treatment (average, 118 mo; range, 108-144 mo). MATERIALS AND METHODS: The study sample included 30 (79%) of 38 participants who had completed a previous NGVB study using a 10% carbamide peroxide solution (Proxigel or Gly-Oxide) in a custom tray for 6 weeks. Participants were asked whether there had been any change in the shade of their teeth post-treatment and, if so, to quantify the change on a verbal scale. In addition, 19 participants had gingival index and tooth vitality evaluated clinically, external cervical root anatomy evaluated radiographically, and enamel surface changes evaluated microscopically. RESULTS: Thirty-five (92%) of the original 38 participants had successful lightening of their teeth. At approximately 10 years post-treatment (average, 118 mo; range, 108-144 mo), external cervical resorption was not diagnosed and gingival index and tooth vitality findings were considered within the normal expectations for the sample studied, suggesting minimal clinical post-NGVB side effects at approximately 10 years. Scanning electron microscopic observations did not reveal substantial differences between treated and nontreated surfaces. Color stability, as perceived by 43% of the participants, may last approximately 10 years (average, 118 mo; range, 108-144 mo) post-treatment. CLINICAL SIGNIFICANCE: Nightguard vital bleaching using 10% carbamide peroxide is safe and effective, with no noticeable side effects, at approximately 10 years (average, 118 mo; range, 108-144 mo) post-treatment. Color stability, as perceived by 43% of the participants, may last 108 to 144 months post-whitening.

Adult↗