Occurrence of sensitivity during at-home and in-office tooth bleaching therapies with or without use of light sources.

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.

Effect of light irradiation on tooth whitening: enamel microhardness and color change.

The aim of this study was to evaluate the influence of light exposure associated with 35% hydrogen peroxide (Pola Office, SDI, Melbourne, Vic., Australia) or 15% hydrogen peroxide (BriteSmile, Discus, Culver City, CA, USA) on the microhardness and color changes of bovine enamel. Experimental groups were Britesmile + Light (BL) (15% hydrogen peroxide + plasm arc; 4 x 20 minutes), Britesmile + No Light (BN) (BL, no light), Pola office + Light (PL) (35% hydrogen peroxide + LED; 4 x 8 minutes), and Pola office + No light (PN) (PL, no light). Color changes (DeltaE) and the CIELAB (Commission Internationale de l' Eclairage, L* a* b* color system) parameters (L*, a*, and b*) were assessed with a spectrophotometer before (B), immediately (A), 1 day and 7 days after bleaching. The microhardness was measured before (B) and after (A), the obtained data were submitted to a two-way analysis of variance, and DeltaE were submitted to t-test for each period. Only Pola Office, in which the peroxide is associated with the light, improved DeltaE when evaluated immediately after bleaching (p < 0.001). Light exposure did not influence DeltaE after 1 day or 7 days for either bleaching system. The enamel microhardness was not altered after bleaching for BriteSmile. However, enamel microhardness was reduced after bleaching for Pola Office, 283 MPa (+/-21) and 265 MPa (+/-27), respectively. It was concluded that these two bleaching systems were efficient regardless of the light systems used. However, the 35% hydrogen peroxide altered the enamel microhardness. CLINICAL SIGNIFICANCE Enamel microhardness was affected by a 35% hydrogen peroxide in-office bleaching therapy. Moreover, the in-office bleaching outcome was not improved by using the light associated with systems tested in this study. (J Esthet Restor Dent 21:387-396, 2009).

Clinical evaluation of the effectiveness of different bleaching therapies in vital teeth.

The aims of this in vivo study were to compare the effectiveness and color stability of at-home and in-office bleaching techniques and to evaluate whether the use of light sources can alter bleaching results. According to preestablished criteria, 40 patients were selected and randomly divided into four groups according to bleaching treatment: (1) at-home bleaching with 10% carbamide peroxide, (2) in-office bleaching with 35% hydrogen peroxide (HP) without a light source, (3) in-office bleaching with 35% HP with quartz-tungsten-halogen light, and (4) in-office bleaching with 35% HP with a light-emitting diode/laser. Tooth shade was evaluated using the VITA Classical Shade Guide before bleaching as well as after the first and third weeks of bleaching. Tooth shade was evaluated again using the same guide 1 and 6 months after the completion of treatment. The shade guide was arranged to yield scores that were used for statistical comparison. Statistical analysis using the Kruskal-Wallis test showed no significant differences among the groups for any time point (P > .01). There was no color rebound in any of the groups. The bleaching techniques tested were equally effective. Light sources are unnecessary to bleach teeth.

Human pulp responses to in-office tooth bleaching.

OBJECTIVE: To evaluate and compare the responses of human incisor and premolar pulps after bleaching. STUDY DESIGN: A bleaching agent with 38% hydrogen peroxide (H(2)O(2)) was applied on the buccal surface of 10 sound lower teeth (G1: 6 premolars; G2: 4 incisors) for 45 minutes. Three premolars and 3 incisors that received only rubber/pumice prophylaxis were used as control groups G3 and G4, respectively. Two days after the bleaching procedure, the teeth were extracted and processed for histologic evaluation. RESULTS: Only in G2 (4 incisors) were any changes in the pulp detected. In the coronal pulp there was a large zone of coagulation necrosis. The radicular pulp showed mild inflammatory changes manifested as an accumulation of mononuclear cells around congested and dilated blood vessels. No pulpal damage was seen in either of the control groups (G3 and G4) or in group G1. CONCLUSION: Bleaching with 38% H(2)O(2) for 45 minutes causes irreversible pulp damage in lower incisors but not in premolars.

Influência do solvente dos sistemas adesivos e do vácuo na resistência à microtração em esmalte pós-clareação / Influence of adhesive system solvent and vacuum on the microtensile bond strength to bleached enamel

O objetivo deste estudo foi avaliar a influência da composição do sistema adesivo e do vácuo na resistência à microtração ao esmalte bovino pós-clareação. Trinta e dois incisivos bovinos tiveram suas coroas seccionadas longitudinalmente em duas metades, uma (teste) foi clareada (Whiteness HP 35%, FGM) e a outra (controle) não. Os dentes foram distribuídos em 4 grupos (n = 8). Os grupos 1 e 3 foram tratados em vácuo por uma hora e os grupos 2 e 4 não. Nos grupos 1 e 2 foi aplicado o adesivo Single Bond 2 (3M ESPE), e nos grupos 3 e 4 o Prime & Bond 2.1 (Dentsply), sendo todos recobertos com a resina TPH (Dentsply). As interfaces compósito/esmalte foram seccionadas para obter "palitos" com área de +- 0,8 mm², que foram submetidos ao teste de microtração (0,6 mm/min). Os valores obtidos foram submetidos à ANOVA de três entradas (vácuo ou não, clareação ou não e adesivo Single Bond 2 ou Prime & Bond 2.1). Os fatores adesivo (p = 0,925) (Prime & Bond 2.1 = 31,86 +- 7,54; Single Bond 2 = 32,03 +- 6,78) e vácuo 9p = 0,568) (com = 31,42 +- 6,82; sem = 32,47 +- 7,49) não foram estatisticamente significativos, sendo o fator clareação significativo (p <0,0010 (com = 26,45 +- 6,13; sem = 37,45 +- 8,19), mas as interações não. Concluiu-se que, de uma maneira geral, os sistemas adesivos testados apresentaram a mesma resistência adesiva; que a clareação diminuiu a resistência adesiva para ambos os sistemas adesivos, independente de seus solventes; e que a utilização ou não de vácuo não afetou a resistência adesiva.

Estudo do proporcionamento volumétrico propiciado por amalgamador mecânico "Dosamat", em função da quantidade de liga e mercúrio nos depósitos / Study of the volumetric proportion propitiated by mechanical amalgamator in function of the amount of alloy and mercury in the deposits

Os autores se propuseram a comparar o peso de diversas porções de três diferentes tipos de liga para amálgama e de mercúrio, em função da variação da quantidade destes componentes nos respectivos depósitos do amalgamador Dosamat, uma vez que havia dúvida quanto à capacidade de obter-se adequada padronização do proporcionamento obtido por este aparelho, já que o mesmo é volumétrico

Odonto estética: a cor da vaidade / Aesthetic Odontology: the colour of vanity

O clareamento dental feito pelo próprio paciente ganha popularidade. Técnica é contra-indicada para pessoas com propensão ao desenvolvimento de câncer, gestantes, crianças e pacientes especiais

Restauraçäo extensa de amálgama: utilizando pino intra-conduto como meio de retençäo / Extensive amalgama restoration using radicular post for retention

Relato de um caso clínico de restauraçäo extensa de amálgama, retido através de pino intra-conduto, em pré-molar superior que apresentava apenas a parede vestibular remanescente. Säo feitos alguns comentários sobre vantagens e desvantagens da técnica

Estudo in vitro do efeito de três diferentes agentes clareadores sobre a dureza e rugosidade do esmalte dentário bovino / In vitro study of the influence of 3 whitenning agents upon rugosity and vickers hardness of bovine dental enamel

Foi avaliada a influência de três tipos distintos de agentes clareadores sobre a rugosidade e a dureza Vickers do esmalte bovino. Quarenta incisivos centrais inferiores foram divididos em quatro grupos: 1o.) água deionizada (controle); 2o.) peróxido de hidrogênio a 35 por cento; 3o.) Opalescence X-tra e 4o.) Opalescence Regular a 10 por cento. Os ensaios foram executados antes e depois dos tratamentos. As médias iniciais e finais obtidas de rugosidade (expressos em micrometros) foram, respectivamente, de 58,4 e 58,9 para os dentes do grupo 1, de 62,9 e 399,6 para os do 2, de 60,5 e 282,1 para os do 3 e de 56,4 e 58,5 para os do 4; quanto à dureza (expressos em números puros) foram, respectivamente, de 259,2 e 258,9 para os do grupo 1, de 256,7 e 172,8 para os do 2, de 259,7 e 213,1 para os do 3 e de 260,3 e 259,4 para os do 4. Foi estatisticamente constatado que os espécimes dos grupos 2 e 3 mostraram alterações nas propriedades estudadas; consequentemente, receberam um tratamento adicional, denominado ameloplastia com ácido (através de uma aplicação do produto Opalustre), o qual permitiu a recuperação dos valores originais, para ambas as propriedades referidas