Nightguard vital bleaching and its effect on enamel surface morphology.

BACKGROUND: The effect that nightguard vital bleaching (NGVB) has on enamel surface morphology is a subject of debate. Previous studies that have evaluated the effect of NGVB on the enamel surface report minimal changes to changes that appear to worsen post-treatment. The purpose of this in vivo NGVB study was to evaluate by scanning electron microscopy (SEM) the effects that 10% carbamide peroxide has on enamel morphology after 2 weeks of treatment and at 6 months post-treatment. MATERIALS AND METHODS: Ten patients participated in the study. Each participant wore a guard filled with an active whitening solution for 8 to 10 hours per day for 14 treatment days. An impression of the study teeth (maxillary incisors) was taken at baseline, after 14 days of treatment, and at 6 months post-treatment, and an epoxy cast made. The epoxy casts were prepared for viewing under the SEM and photographs were taken at 200 times and 2,000 times magnification. Six examiners evaluated changes in enamel surface morphology by comparing the SEM photographs taken at baseline, on treatment day 14, and at 6 months post-treatment. Still masked, the examiners also compared each patient's baseline:treatment day 14 and baseline:6 months post-treatment photographs with photographs of a known standard. RESULTS: This in vivo study demonstrated that a 14-day regimen of NGVB using a 10% carbamide peroxide solution had minimal effect on the surface morphology of enamel and that the effects did not worsen over time.

Effect of dental unit waterline biocides on enamel bond strengths.

This study evaluated the effects of chemical biocides used to control dental unit waterline biofilm on the bond strength of resin to enamel. Sixty bovine teeth were randomly assigned to six treatment groups. One-way ANOVA revealed a significant difference in means (p < 0.001) and Tukey's multiple range test indicated that three of the experimental groups had significantly lower mean shear bond strengths than the control (p < 0.05). This finding suggests that dental unit waterline biocides may adversely affect adhesion of resin to enamel.

Nightguard vital bleaching: a long-term study on efficacy, shade retention. side effects, and patients' perceptions.

BACKGROUND: The scientific literature is lacking in long-term clinical data on the duration of efficacy and post-treatment side effects of nightguard vital bleaching. PURPOSE: This longitudinal clinical study was undertaken (1) to determine the clinical efficacy and duration of efficacy at 3, 6, and 47 months post treatment of a peroxide-containing whitening solution; (2) to evaluate safety issues with respect to using a peroxide whitening solution; and (3) to determine patients' perceptions of the whitening technique. MATERIALS AND METHODS: This project was part of a nightguard vital bleaching study involving human participants. The study teeth for efficacy and duration of efficacy when using a 10% carbamide peroxide solution were the four maxillary central and lateral incisors, with the tooth shade being taken from the middle third of the tooth. Safety issues evaluated were the changes in gingival index (GI), plaque index (PI), nonmarginal gingival index (NMGI), nongingival oral mucosal index (NGOMI), and tooth vitality (TV). Radiographic changes of the study teeth and the patients' perceptions of tooth sensitivity (TS) or gingival irritation (Girr) during treatment and post treatment were also evaluated. RESULTS: The active 10% carbamide peroxide whitening solution used in this study was effective in lightening teeth (98%), and this effect was sustained at a mean of 47 months post treatment in 82% of the participants. When evaluating safety issues, 66% of the participants using the active solution reported TS or Girr. No one reported TS or Girr or any other adverse effects at the end of the study. CONCLUSIONS: The results of this study concur with those of previously reported studies that nightguard vital bleaching using a 10% carbamide peroxide whitening solution according to the manufacturer's instructions is efficacious and safe, with minimal side effects. In addition, long-term shade retention was reported by 82% of the participants at the end of the study, with no adverse side effects. CLINICAL SIGNIFICANCE: Results of this study should reassure dentists that nightguard vital bleaching is a safe, effective, and predictable method to lighten teeth. The whitening effect lasted up to 47 months in 82% of the patients, with no adverse side effects reported at the end of the study.

Nightguard vital bleaching: dark stains and long-term results.

Since its introduction to dentistry in 1989, nightguard vital bleaching has proven to be a simple and safe procedure for lightening discolored teeth. Efficacy of the technique is 98% for non-tetracycline-stained teeth, and with extended treatment time, tetracycline-stained teeth can be expected to lighten in 86% of cases. Satisfactory retention of the shade change without additional treatment can be expected in 63% of patients 3 years post-treatment and in at least 42% of patients at 7 years. Side effects are usually mild and transient, disappearing within days of treatment completion. Patients report that they are glad they went through the procedure and 98% recommend the procedure to a friend.

Effect of whitening agents containing carbamide peroxide on cariogenic bacteria.

PURPOSE: The purpose of this study was to investigate the in vitro antibacterial effects of three different carbamide peroxide products (Nitewhite, Opalescence, and Proxigel) on cariogenic microorganisms (mutans streptococci [MS] and lactobacilli), and to evaluate the effects of a 10% carbamide peroxide solution (Proxigel) on salivary levels of MS and lactobacilli clinically. MATERIALS AND METHODS: Growth inhibition studies were performed to determine the concentration and exposure time of carbamide peroxide to give total inhibition of recoverable growth of MS and lactobacilli. Paraffin-stimulated saliva samples were collected from subjects before and after 6 weeks of treatment with 10% carbamide peroxide in bleaching trays, and levels of MS and lactobacilli were determined. RESULTS: The growth inhibition studies showed no visible growth of MS or lactobacilli at 24-, 48-, or 72-hour incubation, after a 2-hour exposure to 1% carbamide peroxide. Identical results were obtained with all three carbamide peroxide products. In the clinical study, the mean salivary MS levels, expressed as logarithm colony-forming units per milliliter (CFU/mL), were 5.38 for the pretreatment samples and 5.23 for the post-treatment samples. The differences were not statistically significant (p > .05). However, there was a reduction in logarithm lactobacilli counts from a mean of 4.12 pretreatment to a mean of 2.74 post-treatment. This was statistically significant (p < .05).

Quantitation of vital bleaching by computer analysis of photographic images.

BACKGROUND: The authors investigated the use of computer processing of photographic images to monitor changes in tooth brightness after nightguard vital bleaching, or NGVB. METHODS: Photographs of shade guides and clinical cases (patients' teeth) were taken on 35-millimeter film with electronic flash illumination and processed commercially. A slide scanner was used to digitize images as red, green and blue, or RGB, files, with constant brightness, contrast and linearity settings; the images were then analyzed with commercial software. Relevant image components (that is, teeth or shade guide tabs) were separated, and histograms of various numerical color descriptors were generated for each image component. RESULTS: Analysis of shade tab images showed that the mean pixel intensity for the RGB blue channel, or MPIb, was the most satisfactory brightness descriptor, with clear sequential MPIb increments from lighter to darker shades in each series of colors (A through D) and close correlation with the manufacturer's brightness scale (r = .83). Mathematical analysis of MPIb data for shade tabs in the same image yielded a brightness index that was reproducible and correlated well with the manufacturer's brightness scale. Sequential measurements of this index in three subjects whose teeth were bleached with carbamide peroxide for 14 days correlated well with assessments made by visual shade guide comparisons. CONCLUSIONS: The authors conclude that computer analysis of digitized photographic images with internal color controls provides an index of tooth brightness that is reproducible from image to image. CLINICAL IMPLICATIONS: A brightness index derived from computer analysis of digitized photographic images may be useful for monitoring the effectiveness of NGVB.

Nightguard vital bleaching of tetracycline-stained teeth: 54 months post treatment.

PURPOSE: The purpose of this longitudinal whitening study was to determine the stability, post-treatment side effects, and patient satisfaction after 6 months of active treatment of tetracycline-stained teeth with 10% carbamide peroxide at 0 and 54 months post treatment. MATERIALS AND METHODS: Twelve patients who completed the study (80%) were contacted and asked to participate in a survey concerning their whitening experience. Subjects 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 twelve patients underwent clinical examination. RESULTS: Ten patients (83%) reported no obvious shade change or only a slight darkening not noticed by others. Two (17%) reported a slight darkening that is probably noticeable by other people, but no one reported moderate darkening or significant darkening back to original shade. All respondents (n = 12) denied having to have a crown or root canal that they believed was treatment-related. Examiners who compared preoperative and post-treatment photographs and Vita shade values were in agreement with the patient's perceptions of shade change. The degree of improvement was significant for both the immediate (0 mo) and the 54-month post-treatment comparison with the pretreatment shade (p < .005 and p < .01 respectively). CLINICAL SIGNIFICANCE: Results of this nightguard vital bleaching study indicate that tetracycline-stained teeth can be whitened successfully using extended treatment time, and that shade stability may last at least 54 months after treatment. Patients who participated in this study were overwhelmingly positive about the procedure in terms of shade retention and lack of post-treatment side effects.

Use of different concentrations of carbamide peroxide for bleaching teeth: an in vitro study.

OBJECTIVE: This in vitro study compared the shade changes in extracted teeth during 2 weeks' whitening with 5%, 10%, or 16% carbamide peroxide. METHOD AND MATERIALS: After color calibration, the sole examiner selected 110 extracted unrestored, noncarious teeth, shade A3 or darker on a value-oriented guide. The teeth were randomly distributed into equal color groups. The control group (11 teeth) was treated with 0.9% saline, while the experimental groups (33 teeth each) were treated with 5%, 10%, or 16% carbamide peroxide. The solutions remained on the teeth for 8 hours. The teeth and tray were rinsed with tap water for 2 minutes, then rehydrated in 0.9% saline for 16 hours in the humidifier. The shade was assessed, and the process was repeated daily for 2 weeks. RESULTS: Repeated-measures analysis of variance indicated a significant difference in overall shade values between the control and all carbamide peroxide-treated groups at days 8 and 15. A Kaplan-Meier Survival Analysis indicated a quicker two-tab color change for the 10% and 16% groups than the 5% group. However, continuation of the 5% treatment to 3 weeks resulted in shades that approached the 2-week 10% and 16% values. CONCLUSION: Lower concentrations of carbamide peroxide take longer to whitening teeth but eventually achieve the same result as higher concentrations. Higher concentrations may cause increased sensitivity.

Nightguard vital bleaching removes brown discoloration for 7 years: a case report.

Nightguard vital bleaching with 10% carbamide peroxide was used to remove a brown stain from the maxillary central incisor of a 13-year-old-boy. After 7 years, during which there was no touch-up treatment, the discoloration had not returned. This conservative technique should be considered before more invasive procedures for the treatment of discolored vital teeth in young patients.

Efficacy, longevity, side effects, and patient perceptions of nightguard vital bleaching.

Since its introduction into dentistry in 1989, nightguard vital bleaching has been proven to be a simple and safe procedure to whiten discolored teeth. Efficacy of the technique is 95% for nontetracycline-stained teeth, and with extended treatment time, tetracycline-stained teeth can be expected to lighten in 90% of cases. Satisfactory retention of the shade change can be expected in 63% of patients 3 years posttreatment and at least 35% at 7 years. Side effects are usually mild and transient, disappearing within days of treatment completion. Patients report that they are glad they went through the procedure, and 97% recommend the procedure to a friend.

Risk factors for developing tooth sensitivity and gingival irritation associated with nightguard vital bleaching.

The purpose of this study was to determine risk factors in the development of tooth sensitivity and gingival irritation associated with the nightguard vital bleaching technique. The potential risk factors evaluated (sex, age, reported allergy, whitening solution, number of times the solution was changed daily [its usage pattern], and dental arch) were collected from the daily log form turned in by each of the 64 participants after completion of the 6-week lightening process. Also evaluated for each participant, from color slides, were tooth characteristics such as gingival recession, defective restorations, abfraction lesions, enamel-cementum abrasion, etc, and reported side effects. The generalized Mantel-Haenszel statistic was used to assess the association between the potential risk factors and the development of tooth sensitivity and/or gingival irritation. No statistical relationship existed between age, sex, allergy, tooth characteristics, or the dental arch lightened and the development of side effects. Initially, a statistically significant association existed between side effects and the whitening solution used. However, when the analysis was controlled for usage pattern, this relationship disappeared. Patients who changed the whitening solution more than once a day reported statistically significantly more side effects than did those who did not change the whitening solution during their usage time.

Change in pH of plaque and 10% carbamide peroxide solution during nightguard vital bleaching treatment.

The purpose of this study was to evaluate in vivo changes in the pH of plaque and of a 10% carbamide peroxide solution occurring within the bleaching guard during a 2-hour nightguard vital bleaching procedure. Baseline pH values for plaque and the carbamide peroxide solution were established. A small hole was placed in the anterior interproximal region of the guard to allow placement of the pH electrode. The pH of the carbamide peroxide solution was measured at 5-minute intervals. After 2 hours, the guard was removed and pH of the plaque was remeasured. The procedure was repeated three times on each of four subjects. The mean baseline pH reading for plaque was 6.31 and mean final pH reading was 6.86. The difference was statistically significant. At initial placement of the carbamide peroxide-filled guard, the mean intraguard pH was 4.50 (range of 2.80 to 7.80). The mean peak intraguard pH of 8.06 (range of 7.30 to 8.43), which was significantly different from baseline, was obtained within 31 minutes. The pH of plaque, saliva, and a 10% carbamide peroxide bleaching solution within the guard increased significantly during bleaching and remained significantly elevated for the duration of the study (2 hours).

Effectiveness, side effects and long-term status of nightguard vital bleaching.

In this clinical trial of nightguard vital bleaching for six weeks, 92 percent of the patients experienced some lightening of treated teeth. About 97 percent of patients with teeth stained through aging, inherent discoloration, brown fluorosis or trauma experienced lightening, as did 75 percent with tetracycline-stained teeth. Sixty-six percent experienced side effects, which resolved in 24 to 48 hours. Earliest re-treatment was done after one year in less time. Minimal color change occurred for 74 percent after 1 1/2 years and 62 percent after three years.

Salivary pH changes during 10% carbamide peroxide bleaching.

The purpose of this study was to evaluate the effect on salivary pH of a 10% carbamide peroxide solution when used with a custom-fitted guard for bleaching teeth. Baseline pH values were established for unstimulated saliva and on saliva produced while wearing an empty guard. After insertion of a guard half filled with Proxigel, salivary pH measurements were made at 5-minute intervals until the values returned to baseline levels. Mean salivary pH values were 6.81 +/- 0.11 for unstimulated samples and 6.91 +/- 0.18 after insertion of the empty guard. After insertion of the filled guard, there was a statistically insignificant decrease in salivary pH during the first 5 minutes, followed by an increase above baseline at 10 minutes, to a mean peak value of 7.32 +/- 0.27 at 15 minutes. The difference between the baseline values and the mean peak value at 15 minutes was statistically significant. The results of the study indicated that the pH of saliva increased significantly during the first 15 minutes of nightguard vital bleaching and did not significantly drop below baseline in the first 2 hours after insertion with a moderately low-pH solution.

Efficacy of foam liner in 10% carbamide peroxide bleaching technique.

The purpose of this study was to determine if the use of a foam liner in a tray during the nightguard vital bleaching technique would cause a difference in the rate of bleaching or the final shade of the bleached teeth. Ten subjects were selected who had previously successfully bleached their maxillary arch by using a 10% carbamide peroxide solution. Vacuum-formed guards were fabricated for the mandibular arch so that one quadrant was covered with a conventional-style guard, and the other quadrant was covered with a foam-lined guard. All patients were successful in bleaching their mandibular arch. No patient reported any difference between the two quadrants in the rate of bleaching or in the final shade, nor was any difference apparent to the operators clinically or in photographic evaluation. It appears that the addition of a foam insert does not noticeably alter the clinical result of home bleaching. If bleaching is successful in one arch, it can be expected to be effective in the other arch.

Alcohol, alcoholism, and dental treatment.

The purpose of this article is to inform the dental clinician about the prevalence of alcohol use and abuse and to provide a summary of the effects of alcohol on the body. In addition, the implications of alcohol use and alcoholism as related to dental treatment are examined to aid the practitioner in recognizing and diagnosing alcohol abuse. The increased use of alcohol in all age groups and the increased number of people using, abusing, and becoming dependent upon alcohol requires the practicing dentist to be aware of its many effects.