PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Tooth Bleaching”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46Linked to original sources

Effect of intracanal medicaments on the sealing ability of TERM.

An in vitro leakage study was performed to determine the effect of intracanal medicaments on the sealing ability of Temporary Endodontic Restorative Material (TERM). Fifty extracted mandibular molars with uniform access preparations were restored with TERM after placement of either a dry cotton pellet (control) or a pellet moistened with eugenol, formocresol, CMCP, or a paste of sodium perborate and superoxol. Multiple quantitative measurements were made on each intact specimen at five time intervals after restoration, and, in some cases, after thermocycling. Statistical analysis revealed no significant leakage in the control group, or in the groups which used eugenol, formocresol, or CMCP when they were compared with the control group. Analysis, however, did show significant leakage for the group containing the bleaching paste. The authors concluded that the sealing ability of TERM is not affected by eugenol, formocresol, or CMCP. However, it should not be used for the temporary restoration of teeth being treated by the walking bleach technique.

Borates↗

In vitro evaluation of the cytotoxicity of a bleaching agent.

Cell cultures of L929 and BHK21/C13 cells were used to evaluate the toxicity of a newly introduced bleaching agent (Colgate Platinum) compared to hydrogen peroxide, an established bleaching agent. The cell reaction was determined by a quantitative technique at 24 h and 72 h. Both bleaching materials had a dose-dependent effect on cell viability. Concentrations of hydrogen peroxide causing a 50% decrease in cell number (50% inhibition dose-ID50) were calculated as 0.00034% after 24 h and 0.00001% after 72 h in L929 cells. The ID50 of hydrogen peroxide was found to be 0.00016% after 24 h and 0.00007% after 72 h in BHK21/C13 cells. The ID50 of Colgate Platinum was 0.00074% after 24 h and 0.00045% after 72 h in L929 cells and 0.00055% after 24 h and 0.00024% after 72 h in BHK21/C13 cells. The results showed that, in vitro, both bleaching agents were cytotoxic to fibroblasts and the new bleaching agent was less toxic than hydrogen peroxide.

Animals↗

Integration of composite and ceramic restorations in tetracycline-bleached teeth: a case report.

UNLABELLED: The success of an esthetic rehabilitation depends on the understanding of the patient's need and expectation. The management of patients with moderate to severe tetracycline-stained teeth is very challenging. Tooth whitening may be a valid alternative to more aggressive treatments; however, patients should be aware of the limitations of tooth whitening therapy. Clinicians may select differing treatment plans; tooth whitening can improve intrinsic discoloration in a way so that no further treatment is required. Once tooth whitening is completed, direct or indirect restorative procedures may be afforded to match the existing restoration with the bleached tooth structure. This article describes a conservative clinical approach to rehabilitate the smile of a patient with moderate to severe tetracycline-stained teeth using a combination of tooth whitening and direct composite and indirect porcelain restorations in the maxillary anterior segment. CLINICAL SIGNIFICANCE: The combination of tooth whitening and adhesive restorations allows clinicians a significantly more conservative approach to intrinsically stained teeth; tooth preparation for porcelain veneers and porcelain-fused-to-metal and full-ceramic crowns can be restricted to conditions in which persistent tooth discoloration or significant loss of both dentin and enamel exists.

Adult↗

Penetration of the pulp chamber by carbamide peroxide bleaching agents.

Hydrogen peroxide readily penetrates the pulp chamber of freshly extracted teeth. This study was undertaken to determine whether carbamide peroxide also penetrates the pulp chamber. Freshly extracted teeth were sectioned 2 to 3 mm apical to the cementoenamel junction and the coronal pulpal tissue was removed. Acetate buffer was placed in the pulp chamber to absorb and stabilize any peroxide that might penetrate. The coronal portion of each tooth was immersed in either carbamide peroxide gel or gelled hydrogen peroxide at various concentrations for 15 min at 37 degrees C. The buffer was removed, leukocrystal violet was added, and the optical density of the resulting blue solution was determined spectrophotometrically. Amounts of peroxide found in the pulp chamber after 15 min ranged from 3.3 +/- 0.38 micrograms for the 10% sample to 40.4 +/- 3.51 micrograms for the 30% sample.

Carbamide Peroxide↗

The use of dentinal etching with endodontic bleaching procedures.

The removal of the smear layer from dentinal surfaces has been shown to increase significantly the permeability of dentin in both vital and endodontically treated teeth by opening the orifices of the dentinal tubules. This knowledge has led to the practice of acid etching the intracoronal dentin of endodontically treated teeth prior to nonvital bleaching procedures in order to increase the speed and effectiveness of the bleach. In this study extracted human teeth, which had been stained in vitro, were used to compare the effects of dentinal etching of the pulp chambers with no acid etching in conjunction with "walking bleach" procedures. In one experimental group, the pulp chambers were acid etched with 50% phosphoric acid for 1 min to remove the smear layer prior to insertion of the 30% hydrogen peroxide/sodium perborate bleaching agents. The second group had the same chamber preparation except the acid etching was deleted. Evaluators were unable to distinguish a significant difference between the effectiveness of the bleaching procedures in the two experimental groups.

Acid Etching, Dental↗

The effect of bleaching agent on composite/enamel bonding.

This in vitro study evaluates the effect of an in-office light-activated hydrogen peroxide bleaching agent on the shear bond strength of composite resin to etched enamel. Specimens were divided into 4 groups. Group 1 specimens were not bleached and served as the control; Group 2 consisted of specimens bonded immediately after bleaching; Groups 3 and 4 of specimens bonded 1 and 2 weeks respectively after bleaching. The mean shear bond strengths (MPa) of Groups 2 (14.2 +/- 4.9), 3(19.2 +/- 3.2) and 4 (23.1 +/- 3.7) were lower than the value obtained in Group 1 (25.1 +/- 3.7). Groups 2 and 3 had significantly lower shear bond strengths than the unbleached Group 1 (25.1 +/- 3.7). It is suggested that bonding procedures be postponed for two weeks after any bleaching procedure had been done.

Composite Resins↗

Safety issues relating to the use of hydrogen peroxide in dentistry.

Hydrogen peroxide is used widely in professionally and self-administered products. Hydrogen peroxide is a highly reactive substance which can damage oral soft tissues and hard tissues when present in high concentrations and with exposures of prolonged duration. This report provides an overview of health issues relating to the use of hydrogen peroxide, with an emphasis on safety with prolonged exposure to low concentrations of peroxide products. There is good evidence for the safety of hydrogen peroxide when used at low concentrations on a daily basis over extended periods of time, in self-administered oral health care products such as dentifrices and mouthrinses. These low concentrations neither damage oral hard or soft tissues, nor do they pose a significant risk of adverse long-term effects. Caution should be exercised with the increasingly higher concentration peroxide products used for 'walking' or 'power' bleaching due to the possibility of chemical irritation of oral soft tissues with injudicious use. The volumes of material and application times should be controlled carefully. Thorough education of patients is particularly important with self-applied gels because of the lack of professional supervision with such products. Such education is part of the duty of care of the dentist who supplies bleaching gels for at-home use.

Anti-Infective Agents, Local↗

A clinical evaluation of a bleaching agent used with and without reservoirs.

This in vivo study evaluated the variation of tray fabrication (trays constructed with or without reservoirs) on the degree of color change of teeth and sensitivities associated with using a 15% carbamide peroxide bleaching agent for two hours once daily for 14 days. Patients returned in one, two, three, six and 12 weeks. Color changes were evaluated by subjective shade matching, comparing clinical photographs and through measurements obtained using a color-measuring device. Subjects were asked to keep a daily record of any tooth and gingival sensitivity on the right and left side of their maxillary dental arch for three weeks. Colorimeter data showed that teeth lightened with agent with reservoirs were significantly lighter than teeth lightened with the same agent without reservoirs. However, the amount of lightening was below the threshold of visual differentiation. Shade guide and slide photography data showed no significant differences between teeth lightened with agent with reservoirs compared to teeth lightened with the same agent without reservoirs. In addition, no significant differences in tooth and gingival sensitivity were found between the tray side with reservoirs and those without reservoirs.

Adult↗

In vitro evaluation of toothbrushing abrasion of differently bleached bovine enamel.

PURPOSE: To evaluate in vitro, the effect of different external bleaching agents on the susceptibility of enamel against toothbrushing abrasion. METHODS: 96 bovine enamel specimens were embedded in acrylic resin, polished and covered with tape except for a 1.4 x 10 mm window. The samples were divided into eight groups (A-H), 12 specimens each (A-G) were treated with seven different home-bleaching (A: Whitestrips, B: Rapid White, C: Opalescence 10%, D: Opalescence PF 15%) and in-office-bleaching agents (E: Opalescence Extra, F: Opalescence Quick, G: Opalescence Extra Boost) according to manufacturers' instructions. Before and after each individual bleaching treatment the samples were brushed 40 times in an automatic brushing machine using a slurry containing artificial saliva and fluoridated toothpaste. The control group (Group H) was not bleached, but also brushed. After each cycle the specimens were stored in artificial saliva for 24 hours. RESULTS: After 20 cycles loss of enamel was determined by profilometry, resulting in the following values (mean +/- standard deviation) which were statistically analyzed: Group A: (0.169 microm +/- 0.035), Group B (11.108 microm +/- 0.655), Group C (0.207 microm +/- 0.042), Group D (0.154 microm +/- 0.028), Group E (0.081 microm +/- 0.015), Group F (0.084 microm +/- 0.018), Group G (0.087 microm +/- 0.014), Group H (0.076 microm +/- 0.012). Group B differed significantly from the other groups (r = 0.001). Samples of Groups C, D and A showed a significant difference compared to the control H (r = 0.001). Statistical analysis revealed no significant difference between enamel loss of Groups E, F, G and the Control H. It could be proven that toothbrushing abrasion of bleached enamel may be increased depending on the bleaching agent and application form used. Nevertheless, with the exception of bleaching treatment with Rapid White, toothbrushing abrasion of bleached enamel seems to be clinically less relevant.

Animals↗

Intracoronal bleaching: concerns and considerations.

The history of intracoronal bleaching and the development of the walking bleach technique are reviewed. External cervical resorption associated with intracoronal bleaching is a serious sequela that has been reported in the literature. One explanation given for this phenomenon is that it results from an inflammatory process initiated by the presence of bleaching agents in the attachment apparatus. The basis for this conclusion is discussed. A review of published case reports on external cervical resorption associated with intracoronal bleaching revealed that: 100 per cent of the affected teeth had no intermediate dental base placed, 84 per cent were treated with a thermocatalytic technique, 80 per cent were bleached after the root canal sealer was fully set and 72 per cent had a history of trauma before bleaching. Based on these observations, it should be possible to safely bleach teeth intracoronally provided specific concerns and considerations are taken into account. These are: 1) the use of heat should be avoided; 2) an intermediate dental base should be placed with due respect to the attachment level; and 3) a base should be selected with due respect to its effectiveness in sealing tooth structure.

Borates↗

The effects of peroxide bleaching on composite to enamel bond strength.

OBJECTIVES: The objective of this in vitro study was to evaluate the effects of an in-office type of bleaching regimen on the composite to enamel bond. METHODS: The enamel on forty extracted human teeth was subjected to a 25% hydrogen peroxide bleaching treatment. Ten additional unbleached specimens served as controls (Group A). The 40 bleached specimens were divided into four equal groups (Groups B-E). Composite cylinders were bonded to the prepared surfaces at various time intervals following bleaching. Group B was bonded immediately, Group C at 1 d, Group D at 1 wk, and Group E at 1 mon post-bleaching. RESULTS: Mean shear bond strength values showed a significant decrease in bond strength for Group B. However, the bond strength returned to normal values after 1 d and remained normal for at least 1 mon. Scanning electron microscope examination showed an apparent decrease in the number of resin tags present in the enamel/composite interface for Group B compared with the other groups including controls. SIGNIFICANCE: Polymerization inhibition of the resin bonding agent is the likely mechanism for the effects of the bleaching on bond strength.

Composite Resins↗

A clinical comparison of treatments for endemic dental fluorosis.

A case report is presented describing the treatment for endemic dental fluorosis. Six maxillary anterior teeth were treated, three with an acid-bleach combination technique and three with an acid technique. No clinical differences was noted in treatment time or esthetic results.

Acid Etching, Dental↗

Mineral loss from bovine enamel by a 30% hydrogen peroxide solution.

This study investigated the effect of a 30% hydrogen peroxide bleaching agent on bovine enamel in terms of mineral loss. Contents of mineral elements both in the teeth and bleaching agent were evaluated to estimate the effect of hydrogen peroxide on teeth. Finely polished non-carious bovine incisors (n = 5) were immersed in a 30% hydrogen peroxide solution for 120 h. The amounts of concentrated elements in the bleaching agent (5 mL) were measured using inductively coupled plasma-atomic emission spectrometer and ion chromatograph. The contents of mineral elements in the teeth were measured using an electron probe microanalyzer. The Ca/P ratio in the bleaching agent was approximately 1.99. The amount of Zn in the bleaching agent was below the detection limit. The total content of mineral elements of the unbleached enamel (90.75 +/- 1.58) was slightly greater than that of the bleached enamel (87.44 +/- 0.77). The Ca/P ratio of the bleached enamel was 2.06. The amount of Ca loss from the bleached enamels after 120 h was similar to the amount of Ca loss from teeth exposed to a soft drink or juice for a few minutes. Therefore, mineral loss caused by the bleaching process may not be a threatening factor to teeth.

Animals↗

Effect of bleaching time and temperature on the radicular penetration of hydrogen peroxide.

Extracted human premolars were treated endodontically and bleached intracoronally. The teeth were bleached with 30% hydrogen peroxide for periods of 5, 20, 40 and 60 min at temperatures of 24 degrees C, 37 degrees C and 47 degrees C. A correlation for both bleaching time and temperature and the radicular penetration of hydrogen peroxide was found. No penetration was found after 5 min bleaching at any of the temperatures tested. Prolonging the bleaching time after 5 min increased the hydrogen peroxide penetration at each of the temperatures tested. A rise in the bleaching temperature also increased the hydrogen peroxide penetration although not significantly for all tested periods. It is therefore suggested to minimize the bleaching time and temperature when hydrogen peroxide is used as the oxidizing agent. Bleaching should be limited to separate 5-min periods rather than being performed over a long continuous period.

Adult↗