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Publication
Journal: Critical reviews in oral biology and medicine : an official publication of the American Association of Oral Biologists
August/21/2003
Abstract
Present tooth-bleaching techniques are based upon hydrogen peroxide as the active agent. It is applied directly, or produced in a chemical reaction from sodium perborate or carbamide peroxide. More than 90% immediate success has been reported for intracoronal bleaching of non-vital teeth, and in the period of 1-8 years' observation time, from 10 to 40% of the initially successfully treated teeth needed re-treatment. Cervical root resorption is a possible consequence of internal bleaching and is more frequently observed in teeth treated with the thermo-catalytic procedure. When the external tooth-bleaching technique is used, the first subjective change in tooth color may be observed after 2-4 nights of tooth bleaching, and more than 90% satisfactory results have been reported. Tooth sensitivity is a common side-effect of external tooth bleaching observed in 15%-78% of the patients, but clinical studies addressing the risk of other adverse effects are lacking. Direct contact with hydrogen peroxide induced genotoxic effects in bacteria and cultured cells, whereas the effect was reduced or abolished in the presence of metabolizing enzymes. Several tumor-promoting studies, including the hamster cheek pouch model, indicated that hydrogen peroxide might act as a promoter. Multiple exposures of hydrogen peroxide have resulted in localized effects on the gastric mucosa, decreased food consumption, reduced weight gain, and blood chemistry changes in mice and rats. Our risk assessment revealed that a sufficient safety level was not reached in certain clinical situations of external tooth bleaching, such as bleaching one tooth arch with 35% carbamide peroxide, using several applications per day of 22% carbamide peroxide, and bleaching both arches simultaneously with 22% carbamide peroxide. The recommendation is to avoid using concentrations higher than 10% carbamide peroxide when one performs external bleaching. We advocate a selective use of external tooth bleaching based on high ethical standards and professional judgment.
Publication
Journal: Clinical Oral Investigations
March/29/2010
Abstract
Hydrogen peroxide (H(2)O(2)) is a powerful oxidising agent. It gives rise to agents known to be effective bleaching agents. The mechanisms of bleaching involve the degradation of the extracellular matrix and oxidation of chromophores located within enamel and dentin. However, H(2)O(2) produces also local undesirable effects on tooth structures and oral mucosa. In clinical conditions, the daily low-level doses used to produce tooth whitening never generate general acute and sub-acute toxic effects. Genotoxicity and carcinogenicity only occur at concentrations that are never reached during dental treatments. Some transient adverse effects have been reported on the oral mucosa and the digestive tract if the product is swallowed. Local effects may occur on the oral mucosa and dental tissues during whitening, namely, pulp sensitivity, cervical resorption, release of selected components of dental restorative materials, and alteration of the enamel surface. Most of the local effects are dependent of the technique and concentration of the product so far used, but as the results of bleaching obtained are not stable, repeated treatments add to the adverse effects. The informed decision to administer or not and the control of bleaching effects should stand in the hand of dental surgeons and certainly not as it appears at present, as cosmetics sold without any restriction despite the potential health hazards of peroxides.
Publication
Journal: Lasers in Medical Science
January/27/2011
Abstract
The aim of this clinical study was to evaluate the efficiency of in-office bleaching systems with different light sources for color change and possible side effects such as tooth sensitivity and gingival irritations. Forty healthy volunteers aged 18 years and older (average age 27.3 years), having all their natural healthy teeth in shade A3 or darker on the Vita shade guide, with no restorations on the buccal surfaces and no tooth sensitivity, participated in this study. Participants were randomly assigned to four groups of ten volunteers. Group 1 received bleaching without light activation (Opalescence Xtra Boost, Ultradent); group 2 received bleaching (Laser White 10, Biolase) with a diode laser (810 nm, 10 W/ Laser Smile, Biolase) activation; group 3 received bleaching treatment (Remewhite, Remedent) with a plasma arc lamp (400-490 nm, 2800 mV/cm(2), Remecure CL15), and group 4 received bleaching with a light emitting diode (LED) lamp (By White accelerator, Ensodent) according to the manufacturers' recommendations. The shade was assessed with a classical Vita shade guide (Vita Zahnfabrik) and a digital spectrophotometer (Vita Easy Shade, Vident). The color of teeth was scored at baseline and 1 week after bleaching. Any side effects on teeth or gingiva was recorded by visual analog scale. Results were analyzed statistically, by one-way analysis of variance (ANOVA), Kruskal-Wallis, and Mann-Whitney U tests with Bonferroni correction. All the bleaching techniques resulted in shade change. No significant differences were found in the color change among the four groups with shade guide assessment (P>> 0.05), but spectrophotometer readings exhibited significant differences among the groups (P < 0.05). The overall shade change values expressed as DeltaL, Deltaa, Deltab, DeltaE for group 2 was significantly higher than those for the other groups (P < 0.05). Group 2 also showed lower tooth and gingival sensitivity scores than those of the other groups (P < 0.05). All techniques resulted in shade change. Although the shade guide evaluation did not exhibit any differences among the bleaching treatment groups, spectrophotometer readings showed different findings. The results obtained by the two methods of evaluation of shade change used in this study were different from each other. Bleaching with diode laser resulted in less tooth and gingival sensitivity than the other bleaching systems.
CONCLUSIONS
in-office bleaching systems used with or without light, lead to a shade change. As bleaching with diode laser resulted in less tooth and gingival sensitivity, it might be preferred among in-office bleaching systems.
Publication
Journal: British Dental Journal
June/5/2006
Abstract
Hydrogen peroxide in the form of carbamide peroxide is widely used for tooth whitening (bleaching), both in professionally- and in self-administered products. Adverse effects have become evident. Cervical root resorption is a possible consequence of internal bleaching and is more frequently observed in teeth treated with the thermo-catalytic procedure. Tooth sensitivity is experienced in 15-78% of patients undergoing external tooth bleaching. However, clinical studies addressing other adverse effects are lacking. Direct contact with hydrogen peroxide induces genotoxic effects in bacteria and cultured epithelial cells, but the effect is reduced or totally abolished in the presence of metabolising enzymes. Several carcinogenesis studies, including the hamster cheek pouch model, indicate that hydrogen peroxide (H(2)O(2)) might possibly act as a promoter. Until further clinical research is concluded to address the question of possible carcinogenicity, it is recommended that: tooth-bleaching products using concentrated H(2)O(2) should not be used without gingival protection; that H(2)O(2) containing products should be avoided in patients with damaged or diseased soft tissues. For nightguard vital bleaching, minimal amounts of low dose H(2)O(2) (including in the form of carbamide peroxide) are preferred, thereby avoiding prolonged and concentrated exposures.
Publication
Journal: Journal of Contemporary Dental Practice
August/20/2002
Abstract
Dentin hypersensitivity is a common condition of transient tooth pain associated with a variety of exogenous stimuli. There is substantial variation in the response to such stimuli from one person to another. Except for sensitivity associated with tooth bleaching or other tooth pathology, the clinical cause of dentin hypersensitivity is exposed dentinal tubules as a result of gingival recession and subsequent loss of cementum on root surfaces. The most widely accepted theory of how the pain occurs is Brännström's hydrodynamic theory of dentin hypersensitivity. Dentinal hypersensitivity must be differentiated from other conditions that may cause sensitive teeth prior to treatment. Three principal treatment strategies are used. Dentinal tubules can be covered by gingival grafts or dental restorations. The tubules can be plugged using compounds that can precipitate together into a large enough mass to occlude the tubules. The third strategy is to desensitize the nerve tissue within the tubules using potassium nitrate. Several over-the-counter products are available to patients to treat this condition.
Publication
Journal: Operative Dentistry
March/25/2010
Abstract
This study compared the clinical outcome of bleaching techniques in vital teeth. After IRB approval and informed consent, 90 subjects were selected based on the shade of their anterior teeth (A2 or darker, Vita Classic shade guide). Subjects were assigned to three treatment groups in a split-mouth study design: Group I: HB (at-home bleaching with 10% carbamide peroxide for two weeks) vs OBL (in-office bleaching with 35% hydrogen peroxide, two sessions, two-week intervals, with light irradiation); Group II: OB (in-office bleaching without light irradiation) vs OBL; Group III: HB vs combination (one session plus HB). Color change and color rebound (deltaE) were measured for a 16-week period. Color measurements were carried out with both a spectrophotometer and a shade guide at baseline, 1, 2, 4, 8 and 16 weeks. Tooth sensitivity was evaluated using a VAS scale for 15 days. Both the Student's t-test and Tukey-Kramer test were used to analyze the results (p < 0.05). After one week, one session of OBL followed by HB resulted in lower color values, compared with the other bleaching methods. Group III resulted in the least shade values at one-week evaluation, when compared with the other bleaching methods. After two weeks, HE alone resulted in similar color changes as OB, OBL and OBL+HB. The use of light irradiation did not improve bleaching efficacy (OB = OBL). OBL and OB resulted in higher sensitivity rates than HB.
Publication
Journal: Journal of Esthetic and Restorative Dentistry
April/1/2002
Abstract
OBJECTIVE
This study investigated the effect of the presence, absence, and aging of a heat-enhancing compound (colorant) added to bleaching gel on the temperature rise of the gel itself, as well as the temperature rise within the pulp chamber, when a tooth was exposed to a variety of light-curing units in vitro.
METHODS
An extracted human upper central incisor was fitted with thermocouples placed in the pulp chamber as well as on the facial tooth surface. A temperature-controlled simulated intrapulpal fluid flow was provided to the tooth, and bleaching agent (Opalesence XTRA, Ultradent) containing heat-enhancing colorant, aged colorant, or no colorant was applied to the facial surface. The tooth and light-curing unit were placed in a thermostatically controlled oven at 37 degrees C, and real-time gel and intrapulpal temperature values were recorded digitally. Light-curing units used were a plasma arc light (PAC) (PowerPac, ADT), a conventional quartz tungsten halogen source (QTH) (Optilux 501, Demetron/Kerr), the QTH light used in high-power (bleaching) mode, and an argon ion laser (AccuCure 3000, LaserMed). An exposure scenario simulating light-enhanced bleaching of 10 upper teeth was developed. Temperature rise over the pre-exposure, baseline value associated with the last light exposure in the bleaching sequence was calculated for each curing and bleaching combination. Five replications for each test condition were made. Temperature rise values were compared using analysis of variance (ANOVA) at a preset alpha of 0.05.
RESULTS
When fresh colorant-containing bleach was used, the PAC light increased bleach temperature 39.3 degrees C above baseline. With no added colorant, temperature rise was 37.1 degrees C. The QTH light in bleach mode resulted in gel temperature 24.8 degrees C above baseline, whereas the temperature increase was only 11.5 degrees C when no colorant was used. Conventional QTH light use increased fresh bleach temperature by 17.7 degrees C, whereas an increase of only 11.1 degrees C was measured without colorant. The argon ion laser produced equivalent temperature rise regardless of the presence or freshness of the colorant, approximately 9.4 degrees C. Intrapulpal temperatures were all significantly lower than those recorded in the bleaching gel and ranged from 5 degrees to 8 degrees C. As a rule, the presence of fresh heat-enhancing colorant in the bleaching gel resulted in a significant intrapulpal temperature increase (approximately 1 degrees C) over that reached using other lights. The PAC and the QTH light used in bleach mode induced greater intrapulpal temperature rise than the laser.
CONCLUSIONS
Freshness of bleaching agent incorporating light-activated, heat-enhancing colorant influences temperature rise of bleaching gel and also may increase intrapulpal temperature values. Use of intense lights does elevate bleach temperature and also results in increased intrapulpal temperature that may further impact on patient sensitivity and pulpal health resulting from this treatment.
Publication
Journal: Journal of the American Dental Association
December/14/2009
Abstract
BACKGROUND
Tooth sensitivity has been reported with in-office tooth bleaching. The authors conducted a study to evaluate whether the use of a desensitizing agent before in-office bleaching decreased this sensitivity.
METHODS
Before in-office bleaching with a 35 percent hydrogen peroxide gel (three applications of 15 minutes each), clinicians applied a placebo gel on the buccal surfaces of all teeth in 15 participants in the control group, which was left undisturbed for 10 minutes. The clinicians applied a desensitizing agent to the teeth of 15 participants in the experimental group in the same manner as that described for the control (placebo) group. They repeated this protocol one week later. Patients recorded their tooth sensitivity on a 0-to-4 scale. The authors used t test (alpha = .05) to compare the tooth color changes and the intensity of tooth sensitivity between groups at baseline and immediately after the first and second appointments. The authors used Fisher exact test and t test (alpha = .05), respectively, to analyze the percentage of patients with tooth sensitivity and its intensity.
RESULTS
The use of a desensitizing gel did not affect the bleaching efficacy. Seven participants (46.7 percent) in the experimental group and 13 participants (86.7 percent) in the control group experienced tooth sensitivity (P < .05). The intensity of sensitivity was statistically significantly higher for participants in the control group (P < .05).
CONCLUSIONS
The use of a desensitizing gel (5 percent nitrate potassium/2 percent sodium fluoride) before in-office bleaching did not affect the bleaching efficacy but did reduce tooth sensitivity.
CONCLUSIONS
The use of a desensitizing gel before in-office tooth bleaching can reduce tooth sensitivity, the most common side effect associated with this procedure.
Publication
Journal: Journal of the American Dental Association
September/28/2000
Abstract
BACKGROUND
Vital tooth bleaching for esthetic reasons has gained in popularity during the last few years. However, few studies have investigated the efficacy of daytime bleaching products. The purpose of this double-blind in vivo study was to evaluate the efficacy of 20 percent carbamide peroxide, or CP, and 7.5 percent hydrogen peroxide, or HP, during daytime use. The degree of color change, any color relapse, and tooth or gingival sensitivity were evaluated.
METHODS
Twenty-four patients participated in this study. The bleaching gels were randomly applied to the right and left maxillary anterior teeth. Patients were shown how to place the two bleaching agents in a custom tray for one hour, twice a day for two weeks. Patients returned in one, two, three, six and 12 weeks for color evaluation with the colorimeter and shade guides as well as to have color slide photographs taken. The authors evaluated sensitivity by asking the patients to record daily for 21 days any tooth or gingival sensitivity they experienced.
RESULTS
Use of the 20 percent CP resulted in significantly more lightness than the 7.5 percent HP during the first 14 days of the study, but at the end of the study, there was no significant difference between products with regard to tooth lightness. In addition, the authors found no statistically significant difference between products with regard to gingival or tooth sensitivity.
CONCLUSIONS
Both CP and HP are effective at-home bleaching agents when daytime bleaching is preferred.
CONCLUSIONS
Dentists who choose to use daytime bleaching can select either CP or HP.
Publication
Journal: Operative Dentistry
May/19/2014
Abstract
The aim of this study was to compare the effectiveness of and tooth sensitivity to 10% and 20% carbamide peroxide (CP) home-use bleaching agents and 35% and 38% hydrogen peroxide (HP) in-office bleaching agents, all of which contain desensitizing agents, in a clinical trial. Four agents were evaluated: 10% CP and 20% CP (Opalescence PF 10% and Opalescence PF 20%, Ultradent, both with 0.5% potassium nitrate and 0.11% fluoride ions), 38% HP (Opalescence Boost PF, Ultradent, with 3% potassium nitrate and 1.1% fluoride ions), and 35% HP (Pola Office, SDI, with potassium nitrate). The initial screening procedure included 100 volunteers, aged 18 to 42, with no previous sensitivity or bleaching treatment and with any tooth shade. Volunteers were randomly assigned among the technique/bleaching agent groups. A run-in period was performed 1 week before the beginning of the bleaching treatment. For the home-use bleaching technique, each volunteer was instructed to dispense gel (10% CP or 20% CP) into the trays and then insert them into his or her mouth for at least two hours per night for three weeks. For the in-office bleaching technique, the bleaching agents (38% HP or 35% HP) were prepared and used following the manufacturer's instructions, with three applications performed in each session. Three sessions were carried out with an interval of seven days between each session. The participants were evaluated before, at one week, two weeks, and three weeks after the beginning of the bleaching treatment, and again one and two weeks after the bleaching treatment ended. A shade guide (Vita Classical, Vita) was used by a blinded examiner to perform shade evaluations before bleaching and two weeks after the end of bleaching. At the time of the shade evaluations, tooth sensitivity was also recorded by asking the volunteers to classify the sensitivity during bleaching treatment as absent, mild, moderate, or severe. The present study found that 13.8% of the volunteers withdrew from the study due to tooth sensitivity, and 43.2% of the participants experienced some type of sensitivity during bleaching treatment. The χ(2) test showed that there was a significant prevalence of tooth sensitivity during bleaching treatment using the home-use 20% CP agent, with 71.4% of volunteers reporting any level of tooth sensitivity (p=0.0032). A low prevalence of tooth sensitivity was observed for volunteers who used the in-office 38% HP agent (15.0%). The Wilcoxon test (p<0.05) showed that all of the bleaching treatments were effective in bleaching teeth and that there were no differences between the final color shade results among the treatments (Kruskal-Wallis, p<0.05). This study showed that 43.2% of all the volunteers experienced mild or moderate tooth sensitivity during the treatment with bleaching agents. A higher prevalence of tooth sensitivity was observed for 71.4% of the volunteers who used the 20% CP home-use bleaching agent, which may be ascribed to the peroxide concentration and/or the time/length the agent was in contact with the dental structures.
Publication
Journal: Indian Journal of Medical Research
March/29/2009
Abstract
Emerging evidence supports the theory that some autism spectrum disorders (ASDs) may result from a combination of genetic/biochemical susceptibility, specifically a reduced ability to excrete mercury (Hg), and exposure to Hg at critical developmental periods. Elemental/inorganic Hg is released into the air/water where it becomes methylated and accumulates in animal tissues. The US population is primarily exposed to methyl-Hg by fish consumption. In addition, many pharmaceuticals have been, and some continue to be, a ubiquitous source of danger because they contain mercurials. Mercurials may be found in drugs for the eye, ear, nose, throat, and skin; in bleaching creams; as preservatives in cosmetics, tooth pastes, lens solutions, vaccines, allergy test and immunotherapy solutions; in antiseptics, disinfectants, and contraceptives; in fungicides and herbicides; in dental fillings and thermometers; and many other products. Hg has been found to cause immune, sensory, neurological, motor, and behavioural dysfunctions similar to traits defining/associated with ASDs, and that these similarities extend to neuroanatomy, neurotransmitters, and biochemistry. Furthermore, a review of molecular mechanisms indicates that Hg exposure can induce death, disorganization and/or damage to selected neurons in the brain similar to that seen in recent ASD brain pathology studies, and this alteration may likely produce the symptoms by which ASDs are diagnosed. Finally, a review of treatments suggests that ASD patients who undergo protocols to reduce Hg and/or its effects show significant clinical improvements in some cases. In conclusion, the overwhelming preponderance of the evidence favours acceptance that Hg exposure is capable of causing some ASDs.
Publication
Journal: Journal of Applied Oral Science
January/15/2013
Abstract
This study evaluated color change, stability, and tooth sensitivity in patients submitted to different bleaching techniques.
METHODS
In this study, 48 patients were divided into five groups. A half-mouth design was conducted to compare two in-office bleaching techniques (with and without light activation): G1: 35% hydrogen peroxide (HP) (Lase Peroxide - DMC Equipments, São Carlos, SP, Brazil) + hybrid light (HL) (LED/Diode Laser, Whitening Lase II DMC Equipments, São Carlos, SP, Brazil); G2: 35% HP; G3: 38% HP (X-traBoost - Ultradent, South Jordan UT, USA) + HL; G4: 38% HP; and G5: 15% carbamide peroxide (CP) (Opalescence PF - Ultradent, South Jordan UT, USA). For G1 and G3, HP was applied on the enamel surface for 3 consecutive applications activated by HL. Each application included 3x3' HL activations with 1' between each interval; for G2 and G4, HP was applied 3x15' with 15' between intervals; and for G5, 15% CP was applied for 120'/10 days at home. A spectrophotometer was used to measure color change before the treatment and after 24 h, 1 week, 1, 6, 12, 18 and 24 months. A VAS questionnaire was used to evaluate tooth sensitivity before the treatment, immediately following treatment, 24 h after and finally 1 week after.
RESULTS
Statistical analysis did not reveal any significant differences between in-office bleaching with or without HL activation related to effectiveness; nevertheless the time required was less with HL. Statistical differences were observed between the results after 24 h, 1 week and 1, 6, 12, 18 and 24 months (intergroup). Immediately, in-office bleaching increased tooth sensitivity. The groups activated with HL required less application time with gel.
CONCLUSIONS
All techniques and bleaching agents used were effective and demonstrated similar behaviors.
Publication
Journal: Operative Dentistry
November/2/2011
Abstract
This clinical study evaluated the effects of light-emitting diode (LED)/laser activation on bleaching effectiveness (BE) and tooth sensitivity (TS) during in-office bleaching. Thirty caries-free patients were divided into two groups: light-activated (LA) and non-activated (NA) groups. A 35% hydrogen peroxide gel (Whiteness HP Maxx, FGM Dental Products, Joinville SC, Brazil) was used in three 15-minute applications for both groups. For the LA group, LED/laser energy (Whitening Lase Light Plus, DMC Odontológica, São Carlos SP, Brazil) was used, in accordance with the manufacturer's directions. Two sessions of bleaching were performed at one-week intervals. Color was registered at baseline and after the first and second bleaching sessions using a Vita shade guide. Patients recorded TS on a 0 to 4 scale during bleaching and within the next 24 and 48 hours of each session. BE at recall each week and intensity of TS were evaluated by repeated measures analysis of variance (ANOVA) and Tukey tests (α=0.05). Tooth sensitivity was compared using the Friedman repeated measures analysis of variance by rank and the Wilcoxon sign-ranked test. Faster bleaching was observed for the LA group than for the NA group after the first session (4.8 and 3.8 shade guide units [SGUs]; p=0.0001). However, both techniques were capable of bleaching the same number of SGUs after the second bleaching session (p=0.52). Most of the LA group (53.3%) had sensitivity even 24 hours after each bleaching session, but only 26.6% from the NA group reported TS. The intensity of TS was similar for both groups immediately after bleaching but significantly higher for the LA group 24 hours after each bleaching session (p=0.001). After two bleaching sessions, the use of LED/laser light activation did not improve bleaching speed. Persistent tooth sensitivity and higher tooth sensitivity after 24 hours of bleaching were observed when light activation was used.
Publication
Journal: Quintessence International
March/30/1998
Abstract
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.
Publication
Journal: Medical Hypotheses
August/17/2010
Abstract
Vital bleaching procedures are a popular means of improving the appearance of discolored teeth. There is a wide array of whitening products for home and dental office use; all involves placing peroxide containing gels or solutions in contact with the teeth. In order to whiten teeth peroxide has to be able to penetrate tooth structure and oxidize colored compounds in the dentin. Unfortunately beauty comes with a price; many patients undergoing peroxide based whitening procedures complain of bleaching sensitivity (BS) arising in the treated teeth. In BS, pain can occur in healthy intact teeth without any provoking stimulus. Currently the mechanism of nociceptors activation in BS is unknown. A more common form of dental pain-dentin sensitivity (DS) occurs when stimuli such as cold or tactile stimulation contact areas of exposed dentin in otherwise healthy teeth. In DS, stimulation of the dentin results in fluid shifts in the dentinal tubules, these fluid shifts activate mechanosensitive nerve endings in the deep dentin and pulp. Since many aspects of BS and DS symptoms differ, it is hypothesized that that the mechanism of pain generation differs for these two conditions. Recently the functional properties of a chemosensitive ion channel-TRPA1 have been described. This channel is activated by a variety of oxidizer compounds including hydrogen peroxide. Pulpal sensory afferents express TRPA1. It is hypothesized that direct activation of intradental nerve activity via TRPA1 is the mechanism of BS pain. If this theory were correct, tooth sensitivity treatments that reduce the excitability of the intradental nerves such as potassium salts, would be the treatment of choice for BS.
Publication
Journal: Journal of Esthetic and Restorative Dentistry
January/20/2013
Abstract
BACKGROUND
Bleaching-related tooth sensitivity has been shown to be facilitated by the presence of enamel defects. A nano-hydroxyapatite (n-HAP) paste has been shown to repair these defects.
OBJECTIVE
Using a randomized clinical trial, an n-HAP paste was investigated to determine its efficacy in reducing bleaching-related tooth sensitivity.
METHODS
An n-HAP paste (Renamel AfterBleach, Sangi Co., Ltd., Tokyo, Japan) and a placebo (zero-HAP) were randomly assigned for use in 42 participants. A 7% hydrogen peroxide gel was used twice daily for 14 days, with use of assigned desensitizer for 5 minutes immediately following. A diary was completed daily for 4 weeks to note: use of the agents and sensitivity on a visual analog scale (VAS). Three aspects of tooth sensitivity were investigated: percentage of participants; number of days; and intensity level. Color change was assessed.
RESULTS
For Groups zero-HAP and n-HAP, respectively, 51 and 29% of participants reported tooth sensitivity (p = 0.06). Days of sensitivity were 76 and 36, respectively (p = 0.001). Change in VAS score from baseline trended higher for group zero-HAP (p = 0.16). Color change was equivalent.
CONCLUSIONS
The data trend indicated group n-HAP experienced less sensitivity over all three measures. Only the number of days of sensitivity was statistically significant.
CONCLUSIONS
Within the limits of the study it can be concluded that the use of the n-HAP paste was associated with a statistically significant reduction in the number of days of tooth sensitivity experienced during active bleaching.
CONCLUSIONS
For those using a tooth whitener without a desensitizing agent, this study indicates that a paste containing nano-hydroxyapatite crystal can effectively reduce the duration of tooth sensitivity.
Publication
Journal: Journal of Dentistry
November/15/2015
Abstract
OBJECTIVE
To assess the whitening effectiveness and the trans-enamel/trans-dentinal toxicity of experimental tooth-bleaching protocols on pulp cells.
METHODS
Enamel/dentine discs individually adapted to trans-well devices were placed on cultured odontoblast-like cells (MDPC-23) or human dental pulp cells (HDPCs). The following groups were formed: G1 - no treatment (control); G2 to G4 - 35% H2O2, 3 × 15, 1 × 15, and 1 × 5 min, respectively; and G5 to G7 - 17.5% H2O2, 3 × 15, 1 × 15, and 1 × 5 min, respectively. Cell viability and morphology were evaluated immediately after bleaching (T1) and 72 h thereafter (T2). Oxidative stress and cell membrane damage were also assessed (T1). The amount of H2O2 in culture medium was quantified (Mann-Whitney; α=5%) and colour change (ΔE) of enamel was analysed after 3 sessions (Tukey's test; α=5%).
RESULTS
Cell viability reduction, H2O2 diffusion, cell morphology alteration, oxidative stress, and cell membrane damage occurred in a concentration-/time-dependent fashion. The cell viability reduction was significant in all groups for HDPCs and only for G2, G3, and G5 in MDPC-23 cells compared with G1. Significant cell viability and morphology recovery were observed in all groups at T2, except for G2 in HDPCs. The highest ΔE value was found in G2. However, all groups presented significant ΔE increases compared with G1.
CONCLUSIONS
Shortening the contact time of a 35%-H2O2 gel for 5 min, or reducing its concentration to 17.5% and applying it for 45, 15, or 5 min produce gradual tooth colour change associated with reduced trans-enamel and trans-dentinal cytotoxicity to pulp cells.
CONCLUSIONS
The experimental protocols tested in the present study provided significant tooth-bleaching improvement associated with decreased toxicity to pulp cells, which may be an interesting alternative to be tested in clinical situations intended to reduce tooth sensitivity and pulp damage.
Publication
Journal: Journal of Esthetic and Restorative Dentistry
April/1/2002
Abstract
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.
OBJECTIVE
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.
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.
CONCLUSIONS
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.
Publication
Journal: Operative Dentistry
January/9/2012
Abstract
OBJECTIVE
The aim of this study was to evaluate whether the use of a gel applied for 1 × 45 minutes would have the same bleaching rate and tooth sensitivity levels when compared with 3 × 15-minute applications.
METHODS
In-office bleaching was performed in 30 participants with 35% hydrogen peroxide gel. In one group (n=15; 3 x 15 minutes), the bleaching agent was refreshed every 15 minutes, three times at each bleaching appointment. In the other group (n=15; 1 x 45 minutes) the gel was left undisturbed on the buccal surfaces of all teeth for 45 minutes at each bleaching appointment. This protocol was repeated after one week. The bleaching evaluation was completed by two blinded, calibrated evaluators who compared the baseline color of the maxillary anterior teeth with a value-oriented shade guide after each period. The patients recorded the tooth sensitivity on a 0-4 scale. The color changes were evaluated by appropriate tests (α=0.05). The percentage of patients with tooth sensitivity and its intensity were also statistically analyzed (α=0.05), respectively.
RESULTS
The use of gel for a single 45-minute period (1 x 45 minutes) decreased the bleaching efficacy (p<0.05) 86.7%, and 100% of patients from the 3 × 15-minute and 1 × 45-minute groups, respectively, experienced tooth sensitivity (p=0.22). The intensity of sensitivity was lower for the 3 × 15-minute applications (p=0.04).
CONCLUSIONS
A 35% hydrogen peroxide gel for in-office bleaching preferably should be applied in three 15-minute applications because 1 × 45 minutes reduces the bleaching speed and slightly increases the intensity of tooth sensitivity.
Publication
Journal: Journal of Dentistry
January/7/2013
Abstract
OBJECTIVE
To evaluate the influence of light on bleaching efficacy and tooth sensitivity during in-office vital bleaching.
METHODS
We performed a literature search using Medline, EMBASE and Cochrane Central up to September 2011.
METHODS
All randomised controlled trials (RCTs) or quasi-RCTs comparing the light-activated bleaching system with non-activation bleaching system were included. Reports without clinical data concerning bleaching efficacy or tooth sensitivity were excluded.
RESULTS
Eleven studies were included in the meta-analysis. A light-activated system produced better immediate bleaching effects than a non-light system when lower concentrations of hydrogen peroxide (15-20% HP) were used (mean difference [MD], -1.78; 95% confidence interval [CI]: [-2.30, -1.26]; P<0.00001). When high concentrations of HP (25-35%) were employed, there was no difference in the immediate bleaching effect (MD, -0.39; 95% CI: [-1.15, 0.37]; P=0.32) or short-term bleaching effect (MD, 0.25; 95% CI: [-0.47, 0.96]; P=0.50) between the light-activated system and the non-light system. However, the light-activated system produced a higher percentage of tooth sensitivity (odds ratio [OR], 3.53; 95% CI: [1.37, 9.10]; P=0.009) than the non-light system during in-office bleaching.
CONCLUSIONS
Light increases the risk of tooth sensitivity during in-office bleaching, and light may not improve the bleaching effect when high concentrations of HP (25-35%) are employed. Therefore, dentists should use the light-activated system with great caution or avoid its use altogether. Further rigorous studies are, however, needed to explore the advantages of this light-activated system when lower concentrations of HP (15-20%) are used.
Publication
Journal: Operative Dentistry
May/22/2011
Abstract
CLINICAL OBJECTIVE: This clinical study evaluated whether the use of a desensitizing agent (5% potassium nitrate/2% sodium fluoride) before in-office light-activated bleaching decreased this sensitivity.
METHODS
Before in-office bleaching with 35% hydrogen peroxide gel (three applications, 15 minutes each) associated with an LED/laser unit, clinicians applied a placebo gel or the desensitizing agent on the buccal surfaces of all participants. They repeated this protocol one week later. Patients recorded their tooth sensitivity on a 0-to-4 scale. The authors used one-way repeated measures ANOVA to compare the tooth color changes and non-parametric statistics to compare the different percentages of patients with tooth sensitivity and the levels of tooth sensitivity in the different periods of time between groups (α=0.05).
RESULTS
The use of a desensitizing gel did not affect the bleaching efficacy. Eighty percent and 100% of the participants from the experimental and placebo groups, respectively, experienced tooth sensitivity (p>0.05). The intensity of sensitivity was similar immediately after bleaching for both groups (p>0.05). After 24 hours, lower sensitivity was reported in the experimental group, while most of the participants from the placebo group experienced tooth sensitivity (p<0.05).
Publication
Journal: Quintessence International
November/9/1998
Abstract
OBJECTIVE
A 6-month, double-blind study was undertaken to assess the efficacy and safety of a 10% carbamide peroxide gel designed for at-home tooth bleaching.
METHODS
Sixty patients were randomized into two equal subgroups balanced by age, gender, and oral health status. Shade guide measurements, color transparency photographs, and colorimeter readings were taken and evaluated at baseline and 1, 2, 3, 6, 12, and 24 weeks. The active phase of treatment lasted 14 days.
RESULTS
At 22 weeks postbleaching (week 24 of the study), patients receiving the active agent had a 14.1 rank order difference in the shade guide from baseline, and 66% had a clinically observable color change as determined by photographic assessment. They also had a measurable, statistically significant color change from baseline to 6 months of delta E* = 5.0. The tooth color of maxillary incisors stabilized at week 6 and maxillary canines at week 12. The mean color change lost from weeks 2 to 24 was 45% (in delta E*). Transient tissue and tooth sensitivity, noted in some patients, resolved after treatment was completed.
CONCLUSIONS
The product tested is an effective and safe tooth-whitening agent.
Publication
Journal: Acta odontologica latinoamericana : AOL
October/24/2012
Abstract
The aim of this study was to evaluate the effect of tooth bleaching with 10% carbamide peroxide (CP) or 35% hydrogen peroxide (HP), with or without quartz-tungsten-halogen light or hybrid source LED/infrared laser exposition on the occurrence duration, intensity and location of tooth sensitivity Forty patients were selected and randomly divided into four groups: GI--home bleaching with CP for 4 hours a day, over the course of 3 weeks; GII--three sessions of HP with three 10-minute applications at each session and no light source; GIII--the same procedure as GII with quartz-tungsten-halogen light irradiation; GIV--the same procedure as GII with LED/laser light irradiation. The evaluation included an appointment with each patient before and after each HP bleaching session or each weekly CP bleaching and 7, 30 and 180 days after the end of treatment. The Kruskal-Wallis test revealed that the duration and intensity of post-treatment sensitivity were significantly higher for HP than for CP (p< 0.05), and symptoms were located predominantly in anterior teeth. All bleaching methods generated sensitivity, which was more frequent in anterior teeth. However, treatment with CP generated lower sensitivity than treatment with HP independently of the light sources.
Publication
Journal: Journal of the American Dental Association
April/24/2005
Abstract
BACKGROUND
The authors undertook a study to measure how the addition of amorphous calcium phosphate (ACP) to a professionally dispensed 16 percent carbamide peroxide equivalent bleaching gel affects tooth color and dentinal hypersensitivity.
METHODS
The authors assigned two groups to use either the test gel containing ACP or a control gel. Both groups used their respective products for three hours daily for 14 days. At checkpoints during the treatment period, the authors studied tooth color, gingival health and three measures of hypersensitivity. They performed double-blinded clinical measurements on days three, seven, 14 and on the fifth day post-treatment.
RESULTS
The test group demonstrated significantly lower (P < .05) mean thermal sensitivity scores compared with baseline (day 14: 0.21 versus 0.31; fifth posttreatment day: 0.06 versus 0.18). Tactile sensitivity also was substantially lower (P < .05) for test subjects (day 14: 0.26 versus 0.48; fifth posttreatment day: 0.06 versus 0.19). Furthermore, at the conclusion of the study, twice as many subjects were free of thermal sensitivity (test group, 80 percent, compared with control group, 40 percent; P < .001) and there was a similar significant (P < .001) percentage difference for tactile sensitivity. Both groups demonstrated equivalent and significant tooth color enhancement as compared with baseline (control: -7.73 shade change versus test: -8.12; P < .05).
CONCLUSIONS
This study demonstrates that ACP could be added to a 16 percent carbamide peroxide equivalent bleaching gel and result in a significant reduction of clinical measures of dentinal hypersensitivity, both during and after treatment.
CONCLUSIONS
The results of this study offer evidence in support of clinical decisions to treat patients with bleaching gel containing ACP when uncompromised tooth whitening efficacy is desired, yet dentinal hypersensitivity may be a concern.
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