In-Office Dental Bleaching Using 37% Carbamide Peroxide Versus 35% Hydrogen Peroxide: A Randomized, Double-Blind Clinical Trial.

OBJECTIVE: Compare the tooth sensitivity (TS) and bleaching efficacy (BE) of in-office dental bleaching performed with 35% hydrogen peroxide (HP) or 37% carbamide peroxide (CP). MATERIALS AND METHODS: Sixty-six participants were randomly divided into two groups according to the bleaching gel applied to the right hemiarch: 35% HP, or 37% CP. TS was recorded immediately after, up to 1, 24, and 48 h after bleaching, using the VAS and NRS scales. BE was assessed before bleaching and 1 month after using color guide units (ΔSGUs) and a spectrophotometer (ΔEab, ΔE00, and ΔWID). TS was assessed using McNemar's and paired t-test (VAS) or Wilcoxon signed rank (NRS). The paired t-test was used to analyze BE (α = 0.05). RESULTS: TS risk and intensity were lower for the 37% CP (p = 0.003 and p < 0.005). Despite significant differences between the groups after 1 month (ΔSGU and ΔE00; p < 0.05), the color measurements of both groups exceeded the 50%:50% perceptibility/acceptability threshold. CONCLUSION: In-office dental bleaching using 37% CP resulted in reduced risk and TS intensity, without prejudice to the BE. CLINICAL RELEVANCE: The use of 37% CP for in-office dental bleaching could decrease TS risk and intensity without affecting BE. TRIAL REGISTRATION: ClinicalTrials.gov identifier: RBR-683qhf.

Does simultaneous versus individual-arch at-home dental bleaching regimen influence patient satisfaction? A randomized clinical trial.

OBJECTIVE: Our randomized, parallel and single-blinded clinical trial evaluated patient level of discomfort during at-home bleaching testing the equivalence between two different protocols for the use of bleaching trays (simultaneous vs. single arch), as well as tooth sensitivity (TS), gingival irritation, (GI) and bleaching efficacy (BE). MATERIALS AND METHODS: We randomized 100 patients into: simultaneous (n = 50) and single arch (n = 50). At-home bleaching was performed with 10% hydrogen peroxide (HP) for 2 weeks for simultaneous group and 4 weeks for single arch group. We assessed patient level of discomfort using 9-item questionnaire. The TS and GI, as well as BE using spectrophotometer and color guide were assessed using the visual analog scale (0-10). Data from level of discomfort and BE were evaluated by Student's t test. The TS and GI were compared using the relative risk and confidence interval (α = 0.05). RESULTS: Only tray adaptation showed a significant effect after the second week (p < 0.002). There was equivalence between groups for level of discomfort (p < 0.01). We found no significant intergroup differences for the risk of TS or GI, nor for intensity. We observed no significant differences between them regarding bleaching efficacy (p > 0.21). CONCLUSIONS: A simultaneous-use protocol for customized at-home dental bleaching trays proved to be equivalent to using single arch for patient level of discomfort and bleaching efficacy, with no significant increase in adverse effects. CLINICAL SIGNIFICANCE: Clinicians may decide whether to use a simultaneous or single arch protocol for tray usage; however, bleaching was achieved more quickly when the trays were worn simultaneously.

Acid Etching with Modified Phosphoric Acid to Increase the Longevity of the Bonded Interface.

PURPOSE: To evaluate the effect of three phosphoric acids modified with chlorhexidine (CHX), benzalkonium chloride (BAC), or proanthocyanidins (PRO) and one conventional phosphoric acid (CON) on the immediate (24 h; IM) and 1-year composite-dentin microtensile bond strength (µTBS) and nanoleakage (NL), using an etch-and-rinse adhesive. MATERIALS AND METHODS: A flat dentin surface was exposed on 28 caries-free extracted molars, which were then randomly assigned to four groups (n = 7). After etching and rinsing with one phosphoric acid per group, the adhesive (Adper Single Bond 2) was applied on a moist dentin surface. Composite buildups (Filtek Z350) were constructed incrementally and bonded stick specimens (0.8 mm2) were prepared and submitted to the microtensile test (0.5 mm/min) immediately (24 h) or after 1 year of water storage. For nanoleakage, 2 bonded sticks from each tooth at each storage period were immersed in 50 wt% ammoniacal silver nitrate, polished, and analyzed by SEM in backscattered mode. Data were submitted to a two-way ANOVA and Tukey's test (α = 0.05). RESULTS: After 1 year, stable µTBS values were observed only for the modified phosphoric acids (CHX, BAC, and PRO). Also, NL was more evident in the CON group than in the CHX, BAC and PRO groups (p < 0.05) after 1-year water storage. CONCLUSIONS: Compared to the control, the phosphoric acid etchants which contained protease inhibitors (CHX, BAC and PA) promoted the stability of composite-dentin microtensile bond strength and showed less nanoleakage after 1 year of water storage. They represent an effective way of prolonging the stability of the composite-dentin bonds without creating an additional bonding step.

Multiple Adhesive Layering Influence on Dentin Bonding and Permeability.

The aim was to evaluate the effect of the number of layers on the microtensile bond strength (µTBS), permeability and nanoleakage of an etch-and-rinse adhesive (Adper Single Bond 2). Different numbers of layers (1, 2 and 4) were applied on dentin susbstrate. Specimens were obtained and tested for µTBS. Stick-shaped samples were analysed by scanning electron microscope, to observe silver nitrate penetration. One-way ANOVA and Tukey tests were applied (α=0.05) for µTBS values. The fracture mode was evaluated under a stereomicroscope and a scanning electron microscope (SEM). Groups with two and four layers of bond showed higher µTBS to dentin and they also showed lower adhesive permeability than ONE layer. The silver nitrate uptake occurred in the hybrid layer in practically all groups. Fracture occurred predominantly at the mixed interface. The authors recommend the application of more than one layer of Adper Single Bond 2, because a single layer showed lower µTBS and higher permeability values.

Five-year Effects of Chlorhexidine on the In Vitro Durability of Resin/Dentin Interfaces.

PURPOSE: To evaluate the effect of an acid containing 2% chlorhexidine (Ac/CHX) or a 2% CHX aqueous solution (Aq/CHX) on the immediate and 5-year bonding properties of resin/dentin interfaces produced by two adhesives. The presence of CHX in these interfaces was also evaluated under micro-Raman spectroscopy. MATERIALS AND METHODS: Forty-two molars were ground to expose a flat dentin surface. In the control group, the surfaces were etched with conventional phosphoric acid, and Prime&Bond NT (PB) and Adper Single Bond 2 (SB) were applied. In Ac/CHX, an acid containing 2% CHX was applied after adhesive application. In the Aq/CHX group, an aqueous solution of 2% CHX was applied for 60 s after etching. After placing the restoration, specimens were prepared and tested using the microtensile bond strength test (µTBS, 0.5 mm/min) immediately or after 5 years. For nanoleakage (NL), specimens at each period were immersed in silver nitrate solution and examined by EDX-SEM. In addition, specimens at each period underwent examination for CHX using micro-Raman spectroscopy. Data were submitted to appropriate statistical analysis (a=0.05). RESULTS: After 5 years, NL was more pronounced in the control than in the Ac/CHX or Aq/CHX (p<0.001). Significant reductions in the µTBS were observed for all groups; however, they were more pronounced for the control (p<0.001). CHX was still present in the hybrid layers Ac/CHX or Aq/CHX groups after 5 years. CONCLUSION: The use of a 2% chlorhexidine-containing acid or the application of an aqueous CHX primer may increase the long-term stability of resin/dentin interfaces.

Effect of medium or high concentrations of in-office dental bleaching gel on the human pulp response in the mandibular incisors.

Objectives: The present study evaluated the pulp response of human mandibular incisors subjected to in-office dental bleaching using gels with medium or high concentrations of hydrogen peroxide (HP). Materials and Methods: The following groups were compared: 35% HP (HP35; n = 5) or 20% HP (HP20; n = 4). In the control group (CONT; n = 2), no dental bleaching was performed. The color change (CC) was registered at baseline and after 2 days using the Vita Classical shade guide. Tooth sensitivity (TS) was also recorded for 2 days post-bleaching. The teeth were extracted 2 days after the clinical procedure and subjected to histological analysis. The CC and overall scores for histological evaluation were evaluated by the Kruskal-Wallis and Mann-Whitney tests. The percentage of patients with TS was evaluated by the Fisher exact test (α = 0.05). Results: The CC and TS of the HP35 group were significantly higher than those of the CONT group (p < 0.05) and the HP20 group showed an intermediate response, without significant differences from either the HP35 or CONT group (p > 0.05). In both experimental groups, the coronal pulp tissue exhibited partial necrosis associated with tertiary dentin deposition. Overall, the subjacent pulp tissue exhibited a mild inflammatory response. Conclusions: In-office bleaching therapies using bleaching gels with 20% or 35% HP caused similar pulp damage to the mandibular incisors, characterized by partial necrosis, tertiary dentin deposition, and mild inflammation.

Clinical versus laboratory adhesive performance to wet and dry demineralized primary dentin.

PURPOSE: To evaluate the influence of dentin moisture on bond strengths of an etch-and-rinse bonding agent to primary dentin clinically and in the laboratory. METHODS: The sample consisted of two groups of 20 caries-free primary second molars: molars in exfoliation period (clinical group) and extracted molars (laboratory group). Class I cavities were prepared in all specimens leaving a flat dentin surface on the pulpal floor. A two-step etch-and-rinse adhesive was vigorously rubbed on either dry (n = 5) or wet demineralized dentin (n = 5) under clinical or laboratory conditions. After restorative procedures, the teeth from the clinical group were extracted after 20 minutes. All samples were processed and underwent microtensile bond strength test and silver nitrate uptake evaluation under scanning electron microscopy. RESULTS: Statistically higher bond strength values were observed when the bonding was performed under laboratory conditions and on a wet demineralized dentin. Most of the failures were adhesive and mixed irrespective of the experimental condition. Silver nitrate uptake occurred in all groups irrespective of the experimental condition. Resin-dentin bond strengths produced in the laboratory in primary teeth may overestimate those produced under clinical circumstances.

The effect of 6-month water storage on the bond strength of self-etch adhesives bonded to dentin.

PURPOSE: To evaluate the microtensile bond strengths (microTBS) of 1-step vs. 2-step self-etch systems to dentin after 24 hours and after 6 months of water storage. METHODS: Resin composite buildups were bonded to occlusal dentin of third molars using the following adhesives: Xeno IV (XE, Dentsply), G-Bond (GB, GC Inc), Clearfil S3 Bond (CS3, Kuraray); Adper Prompt L-Pop (AD, 3M ESPE); Go (GO, SDI), All Bond SE (ABSE 1-step or ABSE 2-step, Bisco) and Clearfil SE Bond (CSE, Kuraray). The bonded sticks (cross-sectioned area of 0.8-0.9 mm2) originated from the same teeth were randomly divided to be tested after 24 hours or after 6 months of water storage. The data was submitted to two-way repeated measures ANOVA and Tukey's test with and without the inclusion of premature failures (PF) (alpha = 0.05). RESULTS: The inclusion of PF resulted in different statistically significant means for CS3, CSE and AD (P<0.05). Only the ABSE2 showed stable bonds after 6 months of water storage (P>0.05).

The use of warm air stream for solvent evaporation: effects on the durability of resin-dentin bonds.

This study evaluated the effect of a warm (W) or cold (C) air-dry stream for solvent evaporation on the immediate (IM) and six-month (6M) resin-dentin bond strength (microTBS) and silver nitrate uptake pattern (SNU) of two-step etch-and-rinse adhesive system (Adper Single Bond [SB] and Prime & Bond 2.1 [PB]). The adhesives were applied on demineralized dentin surfaces and a warm or cold air-dry stream (10 seconds) was applied followed by light-activation (10 seconds). After 24-hours of water storage, the specimens were serially sectioned in the "x" and "y" directions to obtain bonded sticks around 0.8 mm2 to be tested immediately or after six months of water storage. The specimens at each period were immersed in a 50% solution of silver nitrate, photodeveloped and analyzed by SEM for SNU. Higher IM microTBS values were observed for SB under W conditions. Both adhesives showed reductions in microTBS after 6M in both air temperatures. Regarding SEM, a low silver nitrate uptake was observed in the W groups either in IM or 6M for both adhesives.

Bond strength and quality of the hybrid layer of one-step self-etch adhesives applied with agitation on dentin.

OBJECTIVES: This study evaluated the effect of the application mode on the microtensile resin-dentin bond strength (microTBS) and silver nitrate uptake (SNU) of three one-step self-etch adhesives systems (Clearfil S3 Bond [S3], Xeno III [XE] and Adper Prompt L-Pop [AD]). MATERIALS AND METHODS: The occlusal enamel of 30 caries-free extracted molars was removed with a slow-speed diamond saw under copious water-cooling in order to expose a flat dentin surface. The adhesives were applied passively or with agitation. After light-curing (600 mW/cm2 for 10 seconds), composite buildups were constructed incrementally and the specimens were stored in water (37 degrees C/24 hours). The specimens were longitudinally sectioned in the "x" and "'y" direction to obtain bonded sticks (0.8 mm2) to be tested immediately in tension at 0.5 mm/minute. For SNU, two bonded sticks from each tooth were coated with nail varnish, placed in silver nitrate and polished down with SiC paper. The microTBS and SNU data were submitted to two-way ANOVA and Tukey's test (alpha=0.05). RESULTS: Regarding the microTBS, only the main factor mode of application was statistically significant (p = 0.01). All adhesives showed higher microTBS when applied with agitation. Regarding SNU, only the main factor adhesive was statistically significant (p = 0.001). A higher amount of silver nitrate uptake, located in both the hybrid and adhesive layer, occurred for AD, regardless of the mode of application. CONCLUSIONS: Application with agitation on the dentin surface is a clinical tool capable of improving the resin-dentin bond strength of one-step self-etch adhesives; however, this clinical approach does not improve the hybrid layer resistance to silver nitrate uptake.

Effect of mode of application on the microtensile bond strength of a self-etch and etch-and-rinse adhesive system.

UNLABELLED: This study examined the 24-hour microtensile bond strength (microTBS) of a three-step etch-and-rinse (All Bond 3 [AB3]) and a two-step self-etch system (All Bond Self-Etch [ABSE]) to dentin and ground enamel, varying the application mode. METHODS: AB3 was applied according to the following procedures: A-phosphoric acid + adhesive application. The adhesive was then light-cured before resin buildup. B-similar to Procedure A, except that a thin layer of bonding resin was applied over the cured adhesive; C-similar to Procedure B, however, the adhesive was not light-cured before application of the bonding resin. ABSE was applied according to the following procedures: A--the acidic adhesive was applied and light-cured; B--after the acidic adhesive application and light-curing, a thin layer of ABSE Liner was applied and light cured; C--similar to B, however, the acidic adhesive was not light cured before application of the ABSE Liner. Resin composite buildups (Charisma) were bonded to teeth substrates after adhesive application. The bonded specimens were sectioned into beams 0.9 mm2 after storage in water (24 hours/37 degrees C) and subjected to microTBS with a crosshead speed of 0.5 mm/minute. The average values (MPa) obtained in each substrate were subjected to two-way repeated measures ANOVA and the Tukey's test (alpha=0.05). RESULTS: No significant difference was observed among the experimental groups either in ground enamel or dentin. CONCLUSIONS: The 24-hour microtensile bond strength of All Bond 3 and All Bond Self-Etch was similar, regardless the mode of application of the adhesive systems.

A randomized clinical evaluation of a one- and two-step self-etch adhesive over 24 months.

OBJECTIVE: To evaluate the performance of All Bond SE used in a one- or two-step protocol in a 24-month randomized clinical study. METHODS: Thirty-three patients with two similarly sized non-carious cervical lesions participated in this study. A total of 66 restorations were placed, half using the one-step All Bond SE protocol (SE-1) and the other half using the two-step All Bond SE protocol (SE-2). The restorations were evaluated at baseline and after 6, 12 and 24 months following the modified USPHS criteria and analyzed by the McNemar's test and Fisher's exact test (alpha = 0.05). RESULTS: After 24 months, six SE-1 and four SE-2 restorations were rated as Bravo in marginal discoloration The retention rates for SE-1 and SE-2 were 84.8% and 90.9%, respectively, after 24 months. Compared to baseline, the retention rate for SE-1 was statistically lower. CONCLUSIONS: All Bond SE used in the one- or two-step protocol resulted in high retention rates after 24 months.

A 24-month randomized clinical trial of a two- and three-step etch-and-rinse technique.

PURPOSE: This 24-month randomized paired tooth clinical study evaluated the performance of All Bond 3 used in the simplified (2-step) and full (3-step) versions. METHODS: 33 patients, with at least two similar sized non-carious cervical lesions participated in this study. A total of 66 restorations were placed, half using the 2-step All Bond 3 (AB3-2) and the other half using 3-step All Bond 3 (AB3-3). The restorations were placed incrementally using the composite resin Aelite. The restorations were evaluated at baseline and after 6, 12 and 24 months following the modified USPHS criteria. Statistical differences between the adhesive were tested using with McNemar's test and clinical performance over time for each material with the Fisher's exact test (alpha = 0.05). RESULTS: After 24 months, six AB3-2 and four AB3-3 were rated as bravo for marginal discoloration but did not differ from each other significantly (P > 0.05). The retention rates at 24 months of AB3-2 and AB3-3 were 90.9% and 97.0%, respectively (P > 0.05).

Bleaching sensitivity with a desensitizing in-office bleaching gel: a randomized double-blind clinical trial.

OBJECTIVES: This split-mouth study assessed the bleaching sensitivity (risk and intensity) and color change after in-office bleaching using a desensitizing-containing (5% potassium nitrate) and a desensitizing-free 35% hydrogen peroxide gel. The null hypothesis was that there would be no differences between study groups regarding bleaching sensitivity. METHOD AND MATERIALS: Sixty patients participated in this split-mouth study. The subjects received desensitizing-containing hydrogen peroxide in half of the maxillary arch, and the other half received a desensitizing-free hydrogen peroxide, defined by random sequence, in two dental bleaching sessions. The bleaching sensitivity was evaluated during bleaching and from 1 h to 48 h after each bleaching session using a visual analog scale and numeric rating scale; the McNemar test, the Wilcoxon signed-rank test, and the Student-Newman-Keuls test were used for statistical analysis. The color was measured at baseline and 30 days post-bleaching, evaluated with paired t tests (P = .05). RESULTS: Statistically similar risks of bleaching sensitivity were observed (P = 1.000), but the intensity of bleaching sensitivity was lower (P < .011) on average by 1.32 visual analog scale units in the group bleached with the desensitizer-containing gel during up to 24 h assessment times. No statistical difference in color change was observed between groups (P > .321). CONCLUSION: The incorporation of 5% potassium nitrate into in-office bleaching gels does not reduce the risk of bleaching sensitivity, but it reduces its intensity slightly without jeopardizing color change.

Influence of chlorhexidine digluconate concentration and application time on resin-dentin bond strength durability.

Although it is known that chlorhexidine application may preserve resin-dentin bonds from degradation, the lowest optimal concentration and application time have yet to be established. This study evaluated the effects of different concentrations of chlorhexidine digluconate and different application times on the preservation of resin-dentin bonds formed using two etch-and-rinse adhesives. In experiment 1, after acid etching, the occlusal demineralized dentin was rewetted either with water or with 0.002, 0.02, 0.2, 2, or 4% chlorhexidine for 60 s. In experiment 2, the surfaces were rewetted with water, or with 0.002% or 2% chlorhexidine for 15 or 60 s. After this, both adhesives and composite resin were applied and light-cured. Bonded sticks (0.8 mm(2)) were tested under tension (0.5 mm min(-1)) immediately or after 6 months of storage in water. Two bonded sticks from each tooth were immersed in silver nitrate and analyzed quantitatively using scanning electron microscopy. Reductions in microtensile bond strengths and higher silver nitrate uptake were observed for both adhesives when the rewetting procedure was performed with water. Stable bonds were maintained for up to 6 months under all chlorhexidine conditions tested, irrespective of the chlorhexidine concentration and application time. The use of 0.002% chlorhexidine for 15 s seems to be sufficient to preserve resin-dentin interfaces over a 6-month period.

Active application improves the bonding performance of self-etch adhesives to dentin.

OBJECTIVES: To evaluate the effect of application method on immediate and 6-month resin-dentin microtensile bond strength (microTBS) and nanoleakage (NL) of three one-step self-etch adhesives systems (Clearfil S(3) Bond (S3), Xeno III (XE) and Adper Prompt L-Pop (AD)). METHODS: The oclusal enamel of 30 human molar was removed in order to expose a flat dentin surface. The adhesives were applied under two modes: inactive (IN) or active (AC) application. After light-curing (600mW/cm2 for 10s), composite buildups were constructed incrementally and sectioned to obtain bonded sticks (0.8mm2) to be tested in tension immediately (IM) or after 6 months (6M) of water storage. For NL, three bonded sticks from each tooth at each time were coated with nail varnish, placed in silver nitrate and polished down with SiC paper. The microTBS data were submitted to a two-way ANOVA and Tukey's test for each adhesive (alpha=0.05). RESULTS: The AC showed higher microTBS to dentin when compared to IN in both periods of time (p=0.001). Only for AD, lower microTBS was seen after 6M for IN and AC techniques. XE and S3 adhesives applied under IN showed a higher amount of silver penetration throughout the hybrid layer. Low silver nitrate deposition was seen for these adhesives under AC. After 6M, AD showed a higher amount of silver nitrate uptake under IN and AC techniques. CONCLUSIONS: AC improves the bonding performance of all one-step self-etch adhesive systems tested regardless of the time and this tendency was maintained over time.

Evaporating solvents with a warm air-stream: effects on adhesive layer properties and resin-dentin bond strengths.

OBJECTIVES: This study evaluated the effect of a warm or cold air-dry stream for solvent evaporation on the microtensile resin-dentin bond strength (muTBS), nanoleakage pattern (SEM), degree of conversion (DC) and solvent evaporation rates (SE) of an ethanol/water- (Adper Single Bond, [SB] 3MESPE) and an acetone-based (Prime & Bond 2.1, [PB] Dentsply), two-step etch-and-rinse adhesive system. MATERIALS AND METHODS: Adhesives were applied on demineralized dentin surfaces. For SE, a warm or cold air-dry stream (10 s) was applied prior to light-activation (10 s). Bonded sticks (0.8mm2) were tested in tension (0.5 mm/min). Two bonded sticks from each tooth were immersed in a 50% (w/v) solution of silver nitrate (24 h), photodeveloped (8 h) and analyzed by SEM. The DC and solvent evaporation rate of the adhesives were evaluated under FTIR and analytical balance, respectively. Data were analyzed by two-way ANOVA and Tukey test (alpha=0.05). RESULTS: Higher muTBS and lower nanoleakage were observed when the SE step was performed with warm air-dry stream. However, the DC of the adhesives was not altered by the use of a warm air-dry. CONCLUSIONS: The use of a warm air-dry stream seems to be a clinical tool to improve the bond strength and the quality of the hybrid layer (less nanoleakage infiltration), since it might reduce the number of pores within the adhesive layer.

Tooth sensitivity with a desensitizing-containing at-home bleaching gel-a randomized triple-blind clinical trial.

OBJECTIVES: Desensitizing agents are usually included in the composition of bleaching agents to reduce bleaching-induced tooth sensitivity (TS). This randomized clinical trial (RCT) evaluated the risk and intensity of TS and color change after at-home bleaching with a desensitizing-containing (3% potassium nitrate and 0.2% sodium fluoride) and desensitizing-free 10% carbamide peroxide (CP) gel (Whiteness Perfect, FGM). METHODS: A triple-blind, within-person RCT was conducted on 60 caries-free adult patients. Each participant used the gel in a bleaching tray for 3 h daily for 21 days in both the upper and lower dental arches. The absolute risk and intensity of TS were assessed daily through the 0-10 VAS and NRS scale for 21 days. Color change was recorded using shade guides (Vita Classical and Vita Bleachedguide) and the Easyshade spectrophotometer at baseline, weekly and 30 days after the end of the bleaching. The risk and intensity of TS were evaluated by the McNemar and Wilcoxon Signed Rank tests, respectively. Color change (ΔSGU and ΔE) were evaluated by the Mann-Whitney test and a paired t-test, respectively (α = 0.05). RESULTS: No difference in the TS and color change was observed (p > 0.05). CONCLUSIONS: The incorporation of potassium nitrate and sodium fluoride in 10% carbamide peroxide at-home bleaching gel tested in this study did not reduce the TS and did not affect color change (RBR-4M6YR2).

Response of human pulps to different in-office bleaching techniques: preliminary findings.

This study evaluated a whitening effect and the likely side effect (tooth sensitivity and pulp response) of human teeth subjected to different in-office bleaching (IOB) techniques and materials, mainly the presence of calcium in the IOB materials. A calcium-free (CF) and a calcium-containing (CC) 35% hydrogen peroxide (HP) gels were evaluated. The CF was refreshed every 15 minutes, three times (CF 3-15) or in a single 45-min application (CF 1-45) at one bleaching appointment. The CC was used only in a single 45-min application (CC 1-45). Each technique was applied in 5 mandibular incisors scheduled for extraction for different patients. In control group, no tooth bleaching was performed. The tooth colour (TC) and tooth sensitivity (TS) were recorded at baseline and after IOB. The teeth were extracted 2 days after the application of IOB and subjected to histological analysis. The data was submitted to appropriate statistical analysis (α=0.05). The changes of TC were similar between groups and statistically different from the control (p<0.05). However, TS of groups bleached with CF was statistically higher than that recorded for CC and the control (p<0.05). In CF 3-15 and CF 1-45 groups, the coronal pulp tissue exhibited partial necrosis associated with tertiary dentin deposition. In CC 1-45 group smaller area of necrosis occurred only in three bleached teeth in which tertiary dentin deposition was observed. The calcium-containing 35%HP gel could be preferable for in-office bleaching because it caused less tooth sensibility and pulp damage.

PROPOSTA DE TERMO DE CONSENTIMENTO LIVRE E ESCLARECIDO PARA USO DE PROTETORES BUCAIS PERSONALIZADOS / Proposed of informed consent for use of personalized mouthguards

Durante a prática de esportes, especialmente considerando as modalidades de luta, a cavidade oral fica vulnerável aos eventos traumáticos decorrentes do contato entre os esportistas, o que pode comprometer o bom desenvolvimento da atividade e o próprio desempenho do atleta. A utilização de protetores bucais é uma medida fundamental para reduzir a ocorrência dessas injúrias e, principalmente as suas gravidades, favorecendo uma recuperação mais eficaz e rápida. Contudo, é obrigação ética do profissional e prerrogativa legal dos pacientes receber as informações relacionadas ao seu tratamento da forma mais completa possível, bem como certificar-se que os pacientes compreenderam estas questões. Neste trabalho, é apresentada uma proposta de um modelo de Termo de Consentimento Livre e Esclarecido para uso de protetores bucais personalizados, o qual aborda as questões pertinentes à confecção destes dispositivos. Este documento traz inúmeros benefícios para a especialidade, pois apresenta características como o fortalecimento do vínculo de confiança entre o dentista e o paciente atleta, a determinação de benefícios apropriados, riscos e encargos, a compreensão das vulnerabilidades entre as partes e a obtenção de permissões e aprovações. A confecção e o uso de protetores bucais apresentam especificidades importantes e estas devem estar esclarecidas para o paciente.