The influence of desensitizing dentifrices on pain induced by in-office bleaching.

The purpose of this study was to evaluate whether the use of desensitizing dentifrices used 15 days prior to and after in-office tooth bleaching could eliminate or reduce tooth sensitivity. After institutional review board approval and informed consent, 45 subjects were selected and divided into 3 groups according to the dentifrice selected: Colgate Total (CT), Colgate Sensitive Pro-Relief (CS) or Sensodyne ProNamel (SP). The subjects used toothpaste and a toothbrush provided to them for 15 days prior to bleaching. They were then submitted to two in-office bleaching sessions (Whiteness HP Blue Calcium). Their tooth sensitivity was assessed using the Visual Analog Scale (VAS) for a week after each session. Their tooth shade alteration was measured with a Vitapan Classical shade guide to determine if the dentifrices could influence the effectiveness of the bleaching agent. The data were submitted to Wilcoxon, Kruskal-Wallis and Mann-Whitney tests (α = 0.05). The use of desensitizing dentifrices did not affect the bleaching efficacy. In regard to tooth sensitivity, there was a statistically significant difference between the results of the Control Group and Group T2 after the first session (p = 0.048). There was no statistically significant difference in the results for the other groups after the first session. In regard to the second session, there was no statistically significant difference in the results for all the groups. The use of a desensitizing dentifrice containing nitrate potassium reduced tooth sensitivity during the bleaching regimen. Dentifrices containing arginine and calcium carbonate did not reduce tooth sensitivity. Color change was not influenced by the dentifrices used.

The influence of desensitizing dentifrices on pain induced by in-office bleaching

The purpose of this study was to evaluate whether the use of desensitizing dentifrices used 15 days prior to and after in-office tooth bleaching could eliminate or reduce tooth sensitivity. After institutional review board approval and informed consent, 45 subjects were selected and divided into 3 groups according to the dentifrice selected: Colgate Total (CT), Colgate Sensitive Pro-Relief (CS) or Sensodyne ProNamel (SP). The subjects used toothpaste and a toothbrush provided to them for 15 days prior to bleaching. They were then submitted to two in-office bleaching sessions (Whiteness HP Blue Calcium). Their tooth sensitivity was assessed using the Visual Analog Scale (VAS) for a week after each session. Their tooth shade alteration was measured with a Vitapan Classical shade guide to determine if the dentifrices could influence the effectiveness of the bleaching agent. The data were submitted to Wilcoxon, Kruskal-Wallis and Mann-Whitney tests (α = 0.05). The use of desensitizing dentifrices did not affect the bleaching efficacy. In regard to tooth sensitivity, there was a statistically significant difference between the results of the Control Group and Group T2 after the first session (p = 0.048). There was no statistically significant difference in the results for the other groups after the first session. In regard to the second session, there was no statistically significant difference in the results for all the groups. The use of a desensitizing dentifrice containing nitrate potassium reduced tooth sensitivity during the bleaching regimen. Dentifrices containing arginine and calcium carbonate did not reduce tooth sensitivity. Color change was not influenced by the dentifrices used.

Clinical performance of cervical restorations with desensitizing agents: 18-month clinical trial.

PURPOSE: To evaluate the clinical performance and postoperative sensitivity of noncarious Class V restorations with and without the use of a potassium oxalate-based desensitizing agent over a period of 18 months. MATERIALS AND METHODS: One hundred forty cervical lesions (40 patients) were selected and randomly divided into four groups: group 1 (G1) - teeth restored with the application of a potassium oxalate-based desensitizing agent (BisBlock) after acid etching and before the application of the adhesive Adper Single Bond 2; group 2 (G2) - teeth restored using the same adhesive system used in G1, without the use of any desensitizing agent; group 3 (G3) - similar to G1, but using the adhesive One-Step; group 4 (G4) - similar to G3, but without the application of BisBlock. All restorations were evaluated (double blind) after 1 week and 2, 6, 12, and 18 months according to the modified USPHS criteria. The McNemar and chi-square tests were used to analyze the results (p ≤ 0.05). RESULTS: There were no statistical differences between groups restored with or without the use of a desensitizing agent for postoperative sensitvity. After 18 months, retention rates proved to be statistically significantly lower for One-Step than Adper Single Bond 2. CONCLUSION: The use of potassium oxalate-based desensitizing agent did not decrease postoperative sensitivity when it was used under composite resin restorations.

Clinical evaluation of 4% hydrogen peroxide bleaching in mandibular teeth

Introduction: Bleaching agents have been constantly introduced into market; however, the efficacy of new hydrogen peroxides still needs to be evaluated. Objective: The aim of this study was to evaluate in vivo the effectiveness of 4% hydrogen peroxide bleaching agent in color change, bleaching maintenance, tooth sensitivity, and patients' satisfaction. Material and methods: Forty subjects were selected, lower bleaching trays were constructed, and the patients were instructed to apply 4% hydrogen peroxide bleaching agent at home. Shade measurements of the mandibular anterior teeth were carried out with a spectrophotometer and Vita Classical shade guide (VITA) at the following moments: baseline, 14 days, after patients' satisfaction, and after 90 days. In addition, tooth sensitivity was evaluated using a visual analogue scale (VAS) at the first 14 days. Shade measurements were submitted to repeated measures ANOVA with Bonferroni adjustment and level of significance set at 5%. Results: Statistically significant differences were found for mandibular tooth shade after at-home bleaching (p < 0.001). After 14 days of bleaching, 90% of the subjects were not pleased with the achieved bleaching; however, after 27 days most of the patients reported to be satisfied. Tooth sensitivity was reported to range from 1.01 in a scale from 0-10. Conclusion: At-home bleaching using 4% hydrogen peroxide is effective in lower teeth with reduced tooth sensitivity.

Effect of multiple coats of ultra-mild all-in-one adhesives on bond strength to dentin covered with two different smear layer thicknesses.

PURPOSE: To evaluate the effect on bond strength of 1, 2, or 3 coats of two one-step self-etching adhesives on dentin covered with two different smear layer thicknesses. MATERIALS AND METHODS: Flat dentin surfaces from recently extracted third molars were wet ground with 60- or 600-grit SiC paper to produce smear layers of different thicknesses. Adper Easy Bond (3M ESPE) and Clearfil S3 Bond (Kuraray) were applied in 1, 2, or 3 consecutive coats after air drying each coat. ScotchBond Multi Purpose (3M) and Clearfil SE Bond (Kuraray) were used as controls. Composite resin crowns (Filtek Z250, 3M ESPE) were built up, stored for 24 h, and cut in x and y directions. Eight to twelve sticks (0.65 ± 0.05 mm2 of area) from the central area of each tooth were fractured in tension (0.5 mm/min). Sticks from each group were processed for interfacial micromorphological evaluation with SEM. RESULTS: Three-way ANOVA revealed a significant interaction between factors (p < 0.05). Tukey's post-hoc test showed that only when Adper Easy Bond was applied on dentin prepared with 600-grit SiC paper, microtensile bond strength was not significantly affected by the number of coatings. However, the effect of smear layer thickness was only statistically significant when the adhesives were applied in one coat, for both adhesives. When they were applied in two or three coats, smear layer thickness did not significantly affect bond strength (p > 0.05). CONCLUSIONS: The thickness of the smear layer affected the bond strength of both all-in-one adhesives. Additional coats can be beneficial to bond strength, especially with Clearfil S3 Bond.

Performance clínica de dois sistemas adesivos em lesões cervicais não cariosas: 30 meses de acompanhamento / Clinical evaluation of two adhesive systems in noncarious cervical lesions: 30-month clinical trial

Objetivo: Avaliar a performance clínica de dois sistemas adesivos em lesões de Classe V não-cariosas, por 30 meses. Materiais e Métodos: Sessenta e três lesões cervicais não-cariosas foram restauradas com a resina composta Polofil M (Voco) associada aos sistemas adesivos Futurabond NR (Voco) ou Solobond M (Voco). As restaurações foram executadas seguindo dois protocolos adesivos: o adesivo Futurabond NR foi aplicado pela técnica autocondicionante (G1) e o adesivo Solobond M foi utilizado de acordo com a técnica do condicionamento ácido total (G2). As restaurações foram avaliadas após 7 dias, 6, 18 e 30 meses para oscritérios: retenção, descoloração marginal, integridade marginal, sensibilidade pós-operatória e presença de lesão secundária de cárie, de acordo com os critérios USPHS. Os dados foram analisados usando os testes de McNemar e Qui-quadrado (α=0,05). Resultados: Após 30 meses de acompanhamento, 12 restauraçõesforam perdidas, 6 de cada grupo. O percentual de escore alfa para cada grupo foi: retenção (G1: 77,8%; G2:81,2%), descoloração marginal (G1: 66,7%; G2: 80,8%), integridade marginal (G1: 61,9%; G2: 80,8%),sensibilidade pós-operatória (G1: 90,5%; G2: 89,4%) e presença de lesão secundária de cárie (G1: 95,2%;G2: 100%). Não houve diferença estatística entre os grupos para nenhum dos critérios avaliados (p>0,05).Conclusão: Após 30 meses, os dois sistemas adesivos apresentam desempenhos clínicos semelhantes.

Slow progression of dentin bond degradation during one-year water storage under simulated pulpal pressure.

OBJECTIVES: To evaluate the dentin bond durability of simplified adhesives after one-year (1 y) under water storage and simulated pulpal pressure. METHODS: Class I cavities were prepared in sixty human third molars with the pulpal wall located in mid-coronal dentin. The roots were cut off to expose the pulpal chamber, and the teeth were assembled in a pulpal pressure simulator device. A two-step etch-and-rinse adhesive (Single Bond 2/SB), a two-step self-etch adhesive (Clearfil SE Bond/CSE), a three-step self-etch adhesive (Adper Scotchbond SE/SSE) and three all-in-one adhesives (Adper Easy Bond/EB, Clearfil S(3) Bond/S3 and Adhese One/AO) were applied according to manufacturers instructions. No enamel pre-etching was used for the self-etch systems. The cavities were filled with a composite (Z250, 3M ESPE) in four to five horizontal increments and individually cured. Immediately after the final cure, pulpal pressure was set to 15 cm H(2)O. After 24 h and 1 y under simulate pulpal pressure the teeth were cut following a 'nontrimming' microtensile test technique (n=30) and tested in tension. Kruskall-Wallis and post hoc multiple comparisons were used at alpha=0.05. Weibull statistics was applied to SB, CSE and EB. Fractographic analysis of debonded specimens was performed using scanning electron microscopy. RESULTS: At 24 h and 1 y periods, SB showed higher bond strength means than all the others adhesives tested. CSE was not statistically different from EB at 24 h and from EB and SB at 1 y. EB showed bond strength statistically higher than the other three self-etch adhesives, which were not statistically different from each other at 24 h. AO showed significantly lower bond strength than all tested materials after 1 y. For all adhesives the mean bond strength at 1 y were not statistically different from the values measured at 24 h (p>0.05). Shifts in failure mode patterns and Weibull modulus decrease indicate some degree of bond degradation after the 1 y storage period. CONCLUSION: One-year of simulated pulpal pressure did not affect dentin bond strength of simplified adhesives in Class I restorations. Signs of degradation were only revealed by fractographic analysis and reliability parameters.

Clinical performance of vital bleaching techniques.

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.

Avaliação da resistência à tração de reparos de restaurações de resina composta / Evaluation of bonding strength of composite resin restoration repairs

Reparos de resina composta podem evitar a substituição de restaurações com desgaste superficial. O objetivo deste trabalho foi verificar a influência de diferentes tratamentos de superfície e sistemas adesivos na resistência de união entre resinas compostas envelhecidas e reparos. Trinta cubos de resina composta (A3) com 64mm3 foram confeccionados, envelhecidos artificialmente (5000 ciclos de termociclagem) e distribuídos em 3 grupos de acordo com o tratamento de superfície: G1 - condicionamento com ácido fosfórico; G2:asperização com uma ponta diamantada e condicionamento com ácido fosfórico; G3 - jateamento com óxido de alumínio e condicionamento com ácido fosfórico. Cada grupo foi subdividido em dois subgrupos de acordo com o sistema adesivo utilizado: adesivo do sistema Adper Scotchbond MP(BO) ou Adper Single Bond 2(SB). Todos os grupos experimentais receberam uma restauração de resina composta (WE) em 3 incrementos. Um grupo controle foi confeccionado, no qual esses incrementos foram inseridos diretamente sobre o cubo de resina composta não envelhecida. Os espécimes foram armazenados em água destilada a 37ºC por 24 horas e então seccionados longitudinalmente no sentido X e Y para obtenção dos corpos-de-prova com 0,64mm2 de área de adesão. Uma amostra de cada grupo foi confeccionada para avaliar as alterações superficiais provocadas pelos diferentes tratamentos no microscópio eletrônico de varredura. Os dados de resistência de união foram analisados por meio do teste de ANOVA com dois fatores e o detalhamento foi realizado pelos testes de Tukey HSD e Dunnett (α=5%). Os valores de resistência de união e desvios-padrão em MPa foram:G1(BO):60,1±9,2, G1(SB):48,8±21,7, G2(BO):64,4±13,5, G2(SB):64,5±9,0, G3(BO):76,9±14,5, G3(SB):72,6±13,9 e controle 75,6±13,1. Independentemente do agente de união utilizado, o tratamento mecânico da superfície a ser reparada é essencial para o sucesso do procedimento.

Effect of dental bleaching on the microleakage of class V composite restorations / Efeito do clareamento dental na microinfiltração em restaurações classe V de resina composta

Purpose: The purpose of this study was to evaluate the effect of bleaching agents on the microleakage of Class V composite restorations. Methods: Class V cavities were prepared on the buccal surface of 30 bovine incisors with the incisal margin located in enamel and the gingival margin located in dentin. The cavities were restored using the adhesive system Adper SingleBond2 and the composite Filtek Z250. After 24 h, the samples were finished, polished, thermocycled (500 cycles), and randomly divided into three groups (n=10): (G1) bleached with 35% Hydrogen Peroxide, (G2) bleached with 10% Carbamide Peroxide, and (G3) control group. After bleaching, the samples were coated with wax and nail polish varnish, immersed in 0.5% basic fuchsin for 24 h, and cut parallel to the long axis of the tooth at three reference points on the restoration. The slices were photographed to evaluate the dye penetration and scored for microleakage. Data were analyzed by Kruskal-Wallis test. Results: Microleakage was absent in more than 90% and 53% of the margins located in enamel and dentin, respectively. No significant difference in microleakage was found between control and experimental groups. Conclusion: The bleaching agents tested had no effect on microleakage at the adhesive interface in enamel or dentin.

Objetivo: Avaliar os efeitos dos agentes clareadores na microinfiltração em restaurações Classe V de resina composta. Metodologia: Foram preparadas 30 cavidades classe V na face vestibular de incisivos bovinos com a margem incisal localizada em esmalte e a gengival em dentina. As cavidades foram restauradas com o sistema adesivo Adper Single-Bond e resina composta Filtek Z250. Após 24 horas realizou-se o acabamento, polimento e 500 ciclos de termociclagem. Os dentes foram divididos aleatoriamente em 3 grupos (n=10). (G1) clareados com Peróxido de Hidrogênio 35%; (G2) clareados com Peróxido de Carbamida 10%; e (G3) controle. Os espécimes foram recobertos com cera e esmalte de unha e imersos em fucsina básica 0,5% por 24 horas. Transcorrido esse período, as amostras foram seccionados no longo eixo do dente em três pontos da restauração e as fatias fotografadas para analisar a microinfiltração do corante. Os dados (escore) foram analisados por teste de Kruskal-Wallis. Resultados: Mais de 90% e 53% das margens localizadas em esmalte e dentina, respectivamente, não apresentaram microinfiltração. Não houve diferença estatística na microinfiltração dos grupos testados em comparação com o grupo controle. Conclusão: Os agentes clareadores testados não afetaram a microinfiltração na interface adesiva em esmalte e dentina.

Efeito da contaminação salivar na microinfiltração marginal de um sistema adesivo de frasco único / Effect of salivary contamination on marginal microleakage with a one-bottle adhesive system

Objetivo: Avaliar a microinfiltração marginal após a contaminação salivar percebida e despercebida em cavidades restauradas com sistema adesivo de frasco único. Materiais e métodos: Trinta cavidades classe V foram preparadas na vestibular de incisivos bovinos com margem incisal em esmalte e cervical em dentina. Dividiu-se os dentes aleatoriamente em 3 grupos (n = 10). No Grupo I (controle), as cavidades foram restauradas com adesivo Single Bond (3M ESPE) conforme recomendações do fabricante. Grupo II (contaminação despercebida) as cavidades foram contaminadas com saliva após o condicionamento ácido. No Grupo III (contaminação percebida), após a contaminação salivar, as cavidades foram secas com jatos de ar durante 5 segundos. Todas as cavidades foram restauradas com resina composta em dois incrementos. Após 24 horas, os dentes foram termociclados, cobertos com cera pegajosa e esmalte de unha, imersos em corante, lavados, secos, seccionados longitudinalmente e a extensão da microinfiltração foi analisada numa escala de 0-4, sendo os dados submetidos ao teste Kruskall-Wallis. Resultados: A mediana dos escores de esmalte foi: Grupo I = 0, Grupo II = 4 e Grupo III = 0. Observou-se uma menor infiltração no grupo controle e infiltração percebida nas margens em esmalte (p = 0,0339). Nas margens em dentina, a mediana dos escores foi: Grupo I = 1, Grupo II = 4 e Grupo III = 4. O grupo controle promoveu melhor selamento que os Grupos II e III (p = 0,0103). Conclusão: A contaminação salivar exerce um efeito negativo na capacidade de selamento marginal. As margens em esmalte, remover a saliva com jatos de ar mostrou-se uma eficiente forma de restabelecer a integridade marginal.