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A procedure is presented which combines the walking bleach and the external thermocatylitic bleaching technique. This maximizes the bleaching potential of each and minimizes the possibility of subsequent external root resorption.
The purpose of this study was to evaluate the ability of several intracoronal isolating barrier materials to prevent leakage of a bleaching agent into the roots of teeth and to determine whether placement of the barrier material at the cementoenamel junction or below the cementoenamel junction has an effect on the bleaching results of the crowns. Fifty teeth were stained in vitro, and gutta-percha fillings were placed in the root canals. The experimental isolating barriers were placed at the cementoenamel junction or 2 mm below the cementoenamel junction. A walking bleach of Superoxol and sodium perborate was placed in the pulp chamber for three treatments. The roots of the teeth were evaluated for the presence of root decoloration, and the crowns of the teeth were evaluated for bleaching effect. Findings from this study showed a significant difference between gutta-percha alone and gutta-percha with barrier in preventing root decoloration (p less than 0.05). No significant differences were found between the other experimental groups in preventing root decoloration. Placement of an intracoronal isolating barrier material 2 mm below the cementoenamel junction resulted in a more acceptable esthetic bleaching result of the crowns than did placement of barrier material at the cementoenamel junction.
Intracoronal bleaching of nonvital, teeth with 30% hydrogen peroxide is occasionally associated with external cervical root resorption. The exact mechanism by which bleaching induced root resorption occurs is not yet fully understood. The relationship of cementum to the enamel at the cementoenamel junction may have clinical significance. Seventeen single rooted human mandibular premolars extracted atraumatically for orthodontic reasons were used. The radicular hydrogen peroxide penetration in each tooth was measured in vitro by an indirect colorimetric method. Thereafter, the teeth were examined with a scanning electron microscope to determine the type of the cementoenamel junction. It was found that the radicular penetration of 30% hydrogen peroxide was related to the type of cementoenamel junction.
Tetracycline-discolored teeth that are to be restored by porcelain laminate veneers present a clinical challenge. Successfully bleaching such teeth prior to veneering will permit the clinician and technician to overcome the technical difficulties associated with masking dark teeth. This article describes a combined treatment modality in which the teeth are bleached after the preparation for porcelain laminate veneers.
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Explore the source record for details and available documents.
Vital bleaching can be a relatively unpredictable treatment. Photographs of previous cases and cosmetic imaging, although useful, may lead to unrealistic expectations on the part of the patient. The high-tech mystique of computer imaging and viewing one's own teeth has a significant impact on the dental patient. Whether imaged by the dentist or an auxiliary, patients must be aware of alternatives that may exist both before and during treatment. Cosmetic imaging should be used as an adjunct to, not as the prime motivator for, treatment planning in bleaching cases. Excellent communication between the practitioner and patient is the most important factor in assuring positive bleaching results and patient satisfaction.
The effectiveness of combining in-office and at-home nightguard vital bleaching on tetracycline-stained teeth was evaluated. Grade 1 and grade 2 tetracycline stains were eliminated completely in two months by this combination approach. Grade 3 stains, the most severe, were lightened significantly with a reduction in the banding effect. The most common side effect was an increase in tooth sensitivity, especially to cold, while actively in treatment. All patients reported disappearance of the sensitivity after termination of the treatment phase.
This study evaluated in vitro and in situ the potential adverse effects of 10% carbamide peroxide on human enamel using microhardness, calcium loss and surface morphology analysis. Twenty-four enamel slices (4 mm2) were obtained from recently extracted premolars. The specimens were polished under water-cooling down to 1,200-grade sandpaper. After initial microhardness readings (100 g), the specimens were randomly divided into two groups for in situ and in vitro conditions. The specimens were covered with 10% carbamide peroxide for eight hours. After removing the bleaching gel, the in vitro specimens were stored in deionized water and the in situ specimens, included in an intra-oral appliance, were placed in the oral cavity of four volunteers. These cycling sequences took place for 14 days. Upon conclusion of the bleaching treatment, new microhardness readings were performed on all specimens. Calcium dosage was assessed from the bleaching gel collected after initial exposure on day one, then from gel collected between days two and seven and gel collected between day eight and 14 using an atomic absorption spectrophotometer. Surface morphology was observed from two non-treated control specimens and two specimens of each experimental bleached group under SEM evaluation. Statistical analysis (ANOVA and Tukey tests) disclosed that specimens bleached in situ showed similar microhardness to unbleached specimens and had statistically higher (p < 0.01) hardness than in vitro bleached specimens. The loss of calcium in the in vitro situation at 14 days was 2.5 times higher than the in situ condition. SEM micrographs demonstrated that surface alterations were more pronounced in the in vitro condition. The adverse effects of carbamide peroxide on enamel were evident in specimens bleached in vitro but were not seen in situ. The presence of saliva could prevent the demineralizing effect of bleaching gel in situ.
Interest in the use of bleaching for treatment of discolored teeth is increasing. Bleaching, especially at-home mouthguard bleaching, is considered by many professionals to be the most conservative, non-invasive treatment modality currently available.
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.
Nightguard vital bleaching, or NGVB, which involves the use of a 10 percent carbamide peroxide in a custom-fitted mouthguard, has been used with much success since its introduction in 1989. Normal bleaching treatment time is one to two weeks, although times may be extended to months for difficult stains. When used in a professionally supervised manner, nightguard vital bleaching is as safe as any other routinely used dental treatment.
Internal bleaching with a 30 percent hydrogen peroxide solution is aesthetically very successful in the short term; however, in the long term, the success rate falls below 50 percent. This procedure is associated with a risk of external root resorption, documented both clinically and experimentally. The etiology of resorption and the effects of 30 percent hydrogen peroxide on dental tissues suggest that this chemical should be avoided. Internal bleaching is possible using sodium perborate mixed with water. The aesthetic outcome is still acceptable and the potential for resorption may be minimized.
OBJECTIVE: This in vitro study aimed to evaluate the effect of bleaching agents on dentin microhardness during and after bleaching. METHOD AND MATERIALS: Specimens were randomly assigned to seven groups (n = 15): Nite White Excel 2 Z [NW] 10% and 22%; Rembrandt [REM] 10% and 22%; Opalescence [OPA] 10% and 20%; and a placebo agent. The 42-day whitening treatment consisted of daily application of the agents to the dentin surfaces for 8 hours, followed by immersion in artificial saliva for 16 hours. After the bleaching treatment, specimens were kept immersed in artificial saliva for 14 days. Microhardness was measured at baseline, 8 hours, and 7, 14, 21, 28, 35, and 42 days of bleaching and during the posttreatment period (7 and 14 days). RESULTS: The analysis of variance for split-plot showed a significant effect on the interaction between bleaching agent and time. Tukey's test and regression analyses revealed that during the bleaching period, the agents NW 10%, NW 22%, and OPA 20%, which did not differ from each other, did not alter dentin microhardness, showing constant microhardness values. There were no differences among REM 10%, REM 22%, and OPA 10%, which showed significant reductions in microhardness after day 14 compared to other agents. After bleaching procedures, there was an increase in dentin microhardness for all groups. CONCLUSION: Throughout the bleaching treatment, depending on the agent applied, dentin showed a transitory decrease in microhardness values. In the posttreatment period, artificial saliva presented a remineralizing effect on the bleached surfaces.
A randomized, parallel, examiner-blind clinical study was conducted to examine the ability of 2 toothbrushes to maintain teeth whitening after at-home bleaching. Forty subjects used a 15% carbamide peroxide tray bleaching system at home for 2 weeks per the manufacturer's instructions and then were randomly assigned to use either the Sonicare Advance power toothbrush or a manual toothbrush as part of their home oral hygiene routine for 6 months. The color of the labial surfaces of the subjects' maxillary anterior dentition was assessed before bleaching and immediately, 2 months, 3 months, and 6 months after bleaching. Color was assessed by comparison with Vita Classical shade tabs and by digital image analysis in the CIE L*a*b* color space. Both groups demonstrated a rebound effect at the 2-month visit and beyond, with mean Vita shade scores significantly higher than immediately after bleaching. At the 6-month evaluation, a significant difference in the amount of rebound in each group was observed. Specifically, the rebound of the Sonicare brush group was on average 1.12 Vita shades less than that of the manual brush group. The 6-month difference was confirmed through digital image analysis, with the Sonicare brush group 4.8 L* units lighter, corresponding to 2 Vita shades, and 2.1 b* units less yellow than the manual brush group. This clinical trial demonstrates that the Sonicare Advance toothbrush better maintains whitening after bleaching treatment than a manual toothbrush.
341 mottled teeth were bleached with 4% and 18% hydrochloric acid; the mixture of 36% hydrochloric acid, 30% hydrogen peroxide and anesthetic ether; and 30% hydrogen peroxide warmed by infra-red ray lamp. The effects were evaluated clinically. The extracted mottled and normal teeth were treated with the methods mentioned above. The decolouration effects, the structural changes of tooth surface, and the remineralization were examined by scanning electronmicroscopy and polaroid microscopy. The results showed: all of the four methods had the decolouration effects; the decolouration effect was better in the teeth with higher mineralization and the pigmentation existed more superficially; complete decolouration was 94.8% and lightened cases were 5.2%. The mechanism of decolouration seemed to be the dissolution of tooth superficial layer containing pigment. The decalcified tooth surface might be recalcified by the treatment of recalcification solution, or by saliva itself.
AIM: To evaluate the bleaching efficacy of 35% carbamide peroxide, 35% hydrogen peroxide and sodium perborate for intracoronal bleaching of root filled discoloured teeth. METHODOLOGY: Extracted premolars were artificially stained using whole blood then root canal treatment was performed. After obturation, a 2 mm intermediate base was placed 1 mm below the buccal amelo-cemental junction. Intracoronal bleaching was performed in 11 teeth per group, using either 35% carbamide peroxide gel (group CP), 35% hydrogen peroxide gel (group HP) or sodium perborate mixed with distilled water (group SP). The bleaching agents were replaced after 7 days. The shade of the teeth was evaluated at day 0, 7 and 14. The results were analysed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U-test. RESULTS: At the end of 7 days, both groups CP and HP lightened by 8 +/- 3 Vita tab positions, respectively, whereas group SP lightened by 5 +/- 3 tab positions (P < 0.05). At the end of the second bleaching period at day 14, group CP and HP lightened by a further 2 +/- 2 and 2 +/- 3 tab positions, respectively, whereas group SP lightened by a further 3 +/- 4 tab positions. There were no statistical differences between groups at day 14. CONCLUSIONS: Thirty-five per cent carbamide peroxide and 35% hydrogen peroxide were equally effective for intracoronal bleaching, and significantly better than sodium perborate after 7 days. After 14 days, there were no significant differences between the groups. Thirty-five per cent carbamide peroxide can be recommended as an equally effective alternative to hydrogen peroxide for intracoronal bleaching.