Is prolonged bleaching more harmful to dental enamel than daily dietary and hygienic oral habits?

The ultrastructural and mechanical properties of enamel surface were evaluated after prolonged bleaching treatments with 10% carbamide peroxide in the presence or absence of orange juice (erosive challenge) and toothbrushing (abrasive challenge). In total, 145 incisor bovine teeth were used in this study. Twenty-five samples were prepared for the ultrastructural evaluations, and 120 samples were prepared for microhardness and roughness tests. These 120 samples were divided into eight experimental groups (n = 15): G1- artificial saliva; G2- abrasion; G3- erosion; G4- dental bleaching; G5- erosion + abrasion; G6- bleaching + abrasion; G7- bleaching + erosion; and G8- bleaching + erosion + abrasion. All groups were tested at T0 (before treatment), T1 (14 days), T2 (21 days), and T3 (28 days). Two-way analysis of variance for repeated measures and the post hoc Sidak tests (p ≤ 0.05) were used. The roughness evaluation demonstrated an increase in damage for all experimental groups with an increase in the time period. For microhardness, the groups exposed to artificial saliva (AS) and abrasive challenge did not show any differences at any time points, while the other groups showed a decrease in microhardness from T0 to T3. Ultrastructural evaluation showed different surface alterations in response to the treatments. Despite prolonged bleaching periods, the procedure caused lesser enamel surface alterations than exposure to orange juice alone or in combination with brushing.

Is prolonged bleaching more harmful to dental enamel than daily dietary and hygienic oral habits?

Abstract The ultrastructural and mechanical properties of enamel surface were evaluated after prolonged bleaching treatments with 10% carbamide peroxide in the presence or absence of orange juice (erosive challenge) and toothbrushing (abrasive challenge). In total, 145 incisor bovine teeth were used in this study. Twenty-five samples were prepared for the ultrastructural evaluations, and 120 samples were prepared for microhardness and roughness tests. These 120 samples were divided into eight experimental groups (n = 15): G1- artificial saliva; G2- abrasion; G3- erosion; G4- dental bleaching; G5- erosion + abrasion; G6- bleaching + abrasion; G7- bleaching + erosion; and G8- bleaching + erosion + abrasion. All groups were tested at T0 (before treatment), T1 (14 days), T2 (21 days), and T3 (28 days). Two-way analysis of variance for repeated measures and the post hoc Sidak tests (p ≤ 0.05) were used. The roughness evaluation demonstrated an increase in damage for all experimental groups with an increase in the time period. For microhardness, the groups exposed to artificial saliva (AS) and abrasive challenge did not show any differences at any time points, while the other groups showed a decrease in microhardness from T0 to T3. Ultrastructural evaluation showed different surface alterations in response to the treatments. Despite prolonged bleaching periods, the procedure caused lesser enamel surface alterations than exposure to orange juice alone or in combination with brushing.

Influence of the Extended Use of Desensitizing Toothpastes on Dentin Bonding, Microhardness and Roughness

Abstract The aim of this study was to evaluate the influence of an extended use of desensitizing toothpastes (DTs) on dentin bonding, microhardness and roughness. One hundred and twenty bovine incisor teeth were randomly divided into four groups: G1, distilled water (WATER); G2, Colgate Total 12 (CT12); G3, Colgate Sensitive Pro-Relief (CSPR); and G4, Sensodyne Repair ?αμπ; Protect (SRP). Dentin surfaces were etched with 17% EDTA and 2 years of simulated tooth brushing (20,000 cycles) was performed on their surfaces. Knoop microhardness, surface roughness and scanning electron microscopy (SEM) were performed before and after the simulated tooth brushing. For microshear bonding test, a 2-step self-etching adhesive system (Clearfil SE Bond) was used and 0.8 mm diameter composite resin (Filtek Z350 XT) cylinders were built. Microshear test was performed with an orthodontic wire and with a crosshead speed of 0.5 mm/min. The data were analyzed for: 1) bond strength (one-way ANOVA), 2) microhardness intra-group (Student's test) and inter-group (one-way ANOVA/Tukey's test) comparisons, 3) roughness intra-group (Student's test/Wilcoxon's test) and inter-group (Kruskal-Wallis/Student-Newman-Keuls test) comparisons. The extended use of both dentifrices (conventional and for sensitive teeth) did not affect the bond strength and produced a significant increase in microhardness and roughness of the dentin, except for the microhardness of the SRP group. The simulated tooth brushing technique with water produced an increase in roughness, without reducing significantly the dentin microhardness.

Resumo O objetivo deste estudo foi avaliar a influência do uso prolongado de dentifrícios dessensibilizantes (DTs) na adesão, microdureza e rugosidade da dentina. Cento e vinte dentes incisivos bovinos foram divididos aleatoriamente em quatro grupos: G1, água destilada (WATER); G2, Colgate Total 12 (CT12); G3, Colgate Sensitive Pro-alívio (CSPR); e G4, Sensodyne Repair ?αμπ; Protect (SRP). As superfícies dentinárias foram condicionadas com EDTA a 17% e foram realizados 2 anos de escovação dental simulada (20.000 ciclos) em suas superfícies. A microdureza Knoop, rugosidade de superfície e microscopia eletrônica de varredura (MEV) foram realizadas antes e após escovação dental simulada. Para o teste de adesão por microcisalhamento, foi aplicado um sistema adesivo auto condicionante de 2 passos (Clearfil SE Bond) e foram construídos cilindros de resina composta (Filtek Z350 XT) de 0,8 mm de diâmetro. O teste de microcisalhamento foi realizado com um fio ortodôntico e com velocidade de 0,5mm/min. Os dados foram analisados para: 1) resistência de união (ANOVA 1 fator), 2) comparações de microdureza intra grupo (teste t de Student) e inter grupo (ANOVA 1 fator / teste de Tukey), 3) comparações de rugosidade intra grupo (teste t de Student / teste de Wilcoxon) e inter grupo (Kruskal Wallis / teste de Student-Newman-Keuls). O uso prolongado de ambos dentifrícios (convencional e para dentes sensíveis) não interferiu na resistência de união e produziu um aumento significativo na microdureza e rugosidade da dentina, exceto para a microdureza do grupo SRP. A técnica de escovação dental simulada com água promoveu aumento na rugosidade, sem reduzir significativamente a microdureza da dentina.

Influence of the Extended Use of Desensitizing Toothpastes on Dentin Bonding, Microhardness and Roughness.

The aim of this study was to evaluate the influence of an extended use of desensitizing toothpastes (DTs) on dentin bonding, microhardness and roughness. One hundred and twenty bovine incisor teeth were randomly divided into four groups: G1, distilled water (WATER); G2, Colgate Total 12 (CT12); G3, Colgate Sensitive Pro-Relief (CSPR); and G4, Sensodyne Repair ?αµπ; Protect (SRP). Dentin surfaces were etched with 17% EDTA and 2 years of simulated tooth brushing (20,000 cycles) was performed on their surfaces. Knoop microhardness, surface roughness and scanning electron microscopy (SEM) were performed before and after the simulated tooth brushing. For microshear bonding test, a 2-step self-etching adhesive system (Clearfil SE Bond) was used and 0.8 mm diameter composite resin (Filtek Z350 XT) cylinders were built. Microshear test was performed with an orthodontic wire and with a crosshead speed of 0.5 mm/min. The data were analyzed for: 1) bond strength (one-way ANOVA), 2) microhardness intra-group (Student's test) and inter-group (one-way ANOVA/Tukey's test) comparisons, 3) roughness intra-group (Student's test/Wilcoxon's test) and inter-group (Kruskal-Wallis/Student-Newman-Keuls test) comparisons. The extended use of both dentifrices (conventional and for sensitive teeth) did not affect the bond strength and produced a significant increase in microhardness and roughness of the dentin, except for the microhardness of the SRP group. The simulated tooth brushing technique with water produced an increase in roughness, without reducing significantly the dentin microhardness.

Ethanol-wet bonding technique: 18-month clinical evaluation / Técnica de adhesión húmeda en etanol: evaluación clínica a los 18 meses

The objective of this randomized clinical trial was to evaluate the clinical performance up to 18 months of restorations placed using ethanol-wet bonding technique (EWBT) compared with the three-step etch-and-rinse (TSER) and one-step self-etching (OSSE) approaches. Ninety-three non-carious cervical lesions (31 for each group) were restored by one experienced operator in 17 patients under relatively dry conditions using gingival retraction cord, cotton rolls and saliva ejector. Each adhesive system was randomly allocated to one of randomized cervical lesions until the three groups were present in the same subject in equal amounts. The restorations were evaluated at baseline, 6, 12 and 18 months by two blinded and calibrated examiners using the modified US Public Health Service guidelines (USPHS) for the following outcomes: retention (kappa= 1.00), staining and marginal adaptation (kappa=0.81) and analyzed by Fisher's exact and Kruskal-Wallis tests, respectively. No significant differences were observed among groups after 18 months for any of the assessed criteria (p>0.05). The intra-group analysis performed by Cochran's test (for retention) and Wilcoxon test (for marginal adaptation/staining) revealed significant differences between the time intervals baseline/18 months in marginal adaptation (p= 0.0117) and retention (p= 0.0101) for OSSE and in marginal staining for TSER (0.0051) and EWBT (p= 0.0277) groups. The survival analysis for retention criteria and the overall clinical success were performed using a log-rank test and did not show significant differences among groups (p> 0.05). All three adhesives protocols presented similar clinical performance up to 18 months.

El propósito de este ensayo clínico aleatorizado fue evaluar, durante 18 meses, el éxito clínico de las restauraciones realizadas por la técnica de adhesión húmeda en etanol (TAHE) en comparación con las técnicas de grabado independiente de tres pasos (GTP) y de autograbado de un paso (AUP). Un solo operador, especializado en odontología restaurativa, realizó sobre 17 pacientes 93 restauraciones en lesiones cervicales no cariosas (31 para cada grupo). Los diferentes protocolos adhesivos se distribuyeron aleatoriamente en las lesiones cervicales hasta que los tres grupos estuviesen presentes en el mismo paciente y en cantidades iguales. Las restauraciones fueron evaluadas a los 6, 12 y 18 meses, por dos examinadores calibrados y que no participaron del procedimiento restaurador. Las directrices modificadas del Servicio de Salud Pública de Estados Unidos (SSPEU) fueron la base para las evaluaciones de las siguientes variables: retención (kappa= 1,00), adaptación y decoloración marginal (kappa= 0,81). Estas variables fueron analizadas mediante la prueba exacta de Fisher y Kruskal-Wallis, respectivamente. No se observó diferencia significativa entre los grupos después de 18 meses en las tres variables evaluadas (p >0,05). El análisis intra-grupo hecho por la prueba de Cochran (para la retención) y la prueba de Wilcoxon (para la adaptación y decoloración marginal) revelaron diferencias significativas entre los intervalos de tiempo de la línea de base / 18 meses para la retención (p= 0,0101) y adaptación marginal en el grupo AUP (p= 0,0117), y para la decoloración marginal en los grupos GTP (p= 0,0051) e TAHE (p= 0,0277). El análisis de supervivencia para la retención, así como la comparación del éxito clínico de los protocolos adhesivos, fueron realizados con la prueba de log-rank, y no hubo diferencias significativas (p >0,05) entre los grupos. No hubo diferencia en el éxito clínico de los tres protocolos adhesivos después de 18 meses.

Influence of prolonged use of desensitizing dentifrices on dentin bond strength of self-etching adhesive system / Influencia del uso prolongado de pasta dentífrica desensibilizante en la fuerza de unión de la dentina de un sistema adhesivo autocondicionante

Dentin hypersensitivity is a relatively common clinical condition, which affects a large part of the world's population. The objective of this study was to evaluate the influence of previous and prolonged treatment with desensitizing dentifrices (DD) on bond strength to dentin, promoted by a self-etching adhesive system. Seventy non-carious bovine incisors were used, and divided into five groups (n= 14), according to the desensitizing toothpaste used, such as, G1: distilled water (WATER) (control); G2: Colgate Total 12 (CT12) (control); G3: Colgate Sensitive Pro-Relief (CSPR); G4: Sensodyne Rapid Relief (SRR); G5: Sensodyne Repair & Protect (SRP). Teeth had their buccal surfaces flattened until the exposure of dentin, and fragments of 4x4x2 mm were obtained. Fragments were included in polyvinyl chloride (PVC) cylinders and exposed to 17 % EDTA for 1 min. Subsequently, specimens were submitted to 20 000 cycles of simulated dental toothbrushing. After 24 h in artificial saliva, specimens were hybridized (Clearfil SE Bond ­ Kuraray), as well as resin composite cylinders built on dentin surfaces. Samples were stored in distilled water, at 37 C for 24 h, and the shear bond strength was determined. The highest bond strength (MPa) value was seen in CT12 group (4.39), and the lowest one in CSPR group (3.34). Data were statistically analyzed by 1-way ANOVA (ð= 0.05), and results showed that there were no significant differences (p= 0.5986) considering the DD factor. The predominant fracture pattern was cohesive on dentin. The previous and prolonged use of different DD did not affect dentin bond strength promoted by a self-etching adhesive system.

La hipersensibilidad dentinaria es una condición clínica relativamente común, que afecta a una gran parte de la población mundial. El objetivo fue evaluar la influencia del tratamiento previo y prolongado con dentífricos desensibilizantes (DD) en fuerza de adhesión a la dentina, que promueve un sistema adhesivo de autograbado. Se utilizaron 70 incisivos bovinos no cariados, y se dividieron en cinco grupos (n= 14), de acuerdo con la pasta de dientes desensibilizante utilizada: G1: agua destilada (agua) (control), G2: Colgate Total 12 (CT12) (control), G3: Colgate Sensitive Pro-Alivio (CSPR), G4: Sensodyne Rápido Alivio (SRR) y G5: Sensodyne Repair & Protect (SRP). Los dientes tenían sus superficies bucales aplanadas hasta la exposición de la dentina, y se obtuvieron fragmentos de 4x4x2 mm. Los fragmentos se incluyeron en cilindros de cloruro de polivinilo y se expusieron a 17 % de EDTA durante un 1 min. Después, las muestras se sometieron a 20 000 ciclos de cepillado dental simulado. Después de 24 h en saliva artificial, las muestras se hibridaron (Clearfil SE Bond - Kuraray), y cilindros de resina compuesta fueron construidos sobre superficies de dentina. Las muestras se almacenaron en agua destilada, a 37 °C durante 24 h y luego se determinó la resistencia al cizallamiento. El mayor valor de resistencia a la unión (MPa) se observó en el grupo CT12 (4,39), y el menor en el grupo CSPR (3,34). Los datos fueron analizados estadísticamente mediante ANOVA de un factor 1 (ð= 0,05), y los resultados no mostraron diferencias significativas (p= 0,5986) teniendo en cuenta el factor de los DD. El patrón de fractura predominante sobre la dentina fue el cohesivo. El uso previo y prolongado de diferente DD no afectó resistencia de unión a la dentina promovido por un sistema adhesivo de autograbado.

Influence of tooth bleaching on the bonding strength of silorane-based restorative system / Influencia del aclaramiento dental en la fuerza de adhesion del sistema restaurativo a base de silorano

Bleaching procedures can interfere on adhesive bonding of methacrylate-based restorative materials. After introduction of silorane-based composites, little information is available about this interaction. The objective is evaluate the influence of bleaching on enamel shear bond strength of silorane-based restorative system. Forty sound incisive bovine teeth were randomly divided into 04 groups (n= 10), being: G1 (control) ­ not bleached + Clearfil SE Bond (CSEB)/Filtek Z250 (Z250), G2 (control) not bleached + Silorane Adhesive (SA)/Filtek P90 (P90), G3 ­ bleached + CSEB/Z250; G4 ­ bleached + SA/P90. The teeth were sectioned, had crowns included in a PVC rings, and the enamel surfaces gridded and polished with silicon carbide abrasive papers. G1 and G2 were stored in artificial saliva (37 C), daily renewed, for a period of 04 days. G3 and G4 were exposed to 02 sessions of 38% hydrogen peroxide (38HP), with 03 applications of 15 min in each session. Composite resin cylinders were built up on the enamel surfaces. Bonding procedures were performed according the manufacturer's instructions. After storage in distilled water for 24 h (37 C), the samples were submitted to shear bond test. Data were analyzed by two-way ANOVA and t (LSD) tests (5%). Intra group comparison showed significant difference for Z250 after bleaching, but not for P90. Shear strength was significant lower for P90, despite bleaching procedures. In conclusion, 38HP bleaching had no influence on the enamel bond strength of P90, even though presenting lower bond strength than Z250.

Los procedimientos de blanqueamiento dental pueden interferir en la unión adhesiva de los materiales de restauración a base de metacrilato. Después de la introducción de materiales compuestos a base de silorano, hay poca información disponible acerca de esta interacción. El objetivo fue evaluar la influencia del blanqueamiento en la cizalladura de la fuerza de adhesion sobre esmalte del sistema restaurativo a base de silorano. Cuarenta dientes incisivos bovinos fueron divididos aleatoriamente en 4 grupos (n= 10), siendo: G1 (control) - no aclarado + Clearfil SE Bond (CSEB)/Filtek Z250 (z250), G2 (control) - no aclarado + adhesivo de silorane (AS)/Filtek P90 (P90), G3 - aclarado + CSEB / Z250; g4 - aclarado + AS/P90. Los dientes fueron seccionados, tenían coronas incluidas en anillos de pvc, y las superficies de esmalte fueron molidas y pulidas con papeles abrasivos de silicona de silicio. G1 y G2 fueron almacenados en saliva artificial (37 °C), renovada diariamente, durante un período de 04 días. G3 y G4 se expusieron a 2 sesiones de peróxido de hidrógeno al 38% (38 HP) con 03 aplicaciones de 15 min en cada sesión. Los cilindros de resina compuesta fueron construidos en las superficies de esmalte. Los procedimientos de unión se realizaron según las instrucciones del fabricante. Después del almacenamiento en agua destilada durante 24 h (37 °C), las muestras fueron sometidas al ensayo de resistencia de adhesión al cizallamiento. Los datos fueron analizados por ANOVA de dos vías y prueba t (5%). La comparación intragrupo mostró diferencias significativas para Z250 después del aclaramiento, pero no para P90. La resistencia al corte fue significativamente menor para P90, a pesar de los procedimientos de blanqueamiento. En conclusión, el blanqueamiento con 38HP no tuvo influencia en la resistencia de la unión esmalte de P90, a pesar de presentar una fuerza de unión más baja que Z250.

Influence of whitening gel on pulp chamber temperature rise by in-office bleaching technique / Influência do gel clareador no aumento da temperatura intra-câmara pulpar pela técnica do clareamento em consultório

Introduction: Dental bleaching is a conservative method for the aesthetic restoration of stained teeth. However, whitening treatments are likely to cause adverse effects when not well planned and executed. Objective: This study evaluated the influence of whitening gel on temperature rise in the pulp chamber, using the in-office photoactivated dental bleaching technique. Material and Method: The root portion of an upper central human incisor was sectioned 3mm below the cemento-enamel junction. The root canal was enlarged to permit the insertion of the K-type thermocouple sensor (MT-401) into the pulp chamber, which was filled with thermal paste to facilitate the transfer of heat during bleaching. Three photosensitive whitening agents (35% hydrogen peroxide) were used: Whiteness HP (FGM), Whiteness HP Maxx (FGM) and Lase Peroxide Sensy (DMC). An LED photocuring light (Flash Lite - Discus Dental) was used to activate the whitening gels. Six bleaching cycles were performed on each group tested. The results were submitted to one-way ANOVA and LSD t-test ((α≤0,05). Result: The lowest mean temperature variation (ºC) was detected for Lase Peroxide Sensy (0.20), while the highest was recorded for Whiteness HP (1.50). Conclusion: The Whiteness HP and Whiteness HP Maxx whitening gels significantly affected the temperature rise in the pulp chamber during bleaching, and this variation was dependent on the type of whitening gel used.

Introdução: O clareamento dental representa uma manobra conservadora na recuperação estética de dentes com alterações cromáticas. Contudo, os tratamentos clareadores são passíveis de causar efeitos adversos, quando não bem planejados e executados. Objetivo: Este estudo avaliou a influência do gel clareador no aumento da temperatura intra-câmara pulpar através da técnica de clareamento dental fotoativado realizado em consultório. Material e Método: Um incisivo central superior humano foi seccionado na porção radicular 3 mm abaixo da junção cemento-esmalte. O canal radicular foi alargado para permitir a introdução do sensor do termômetro na câmara pulpar, a qual foi preenchida com pasta térmica, favorecendo a transferência de calor das paredes dentárias para o sensor do termômetro digital com termopar tipo K (MT- 401A) durante o clareamento. Três agentes clareadores fotossensíveis (peróxido de hidrogênio a 35%) foram utilizados, sendo: Whiteness HP (FGM), Whiteness HP Maxx (FGM) e Lase Peroxide Sensy (DMC). Um aparelho fotopolimerizador de led (Flash Lite - Discus Dental) foi empregado para a ativação dos géis clareadores. Seis ciclos de clareamento foram realizados para cada grupo testado. Os resultados foram submetidos à ANOVA de um critério e ao teste t (LSD) ((α≤0,05). Resultado: A menor média de variação de temperatura (ºC) foi observada com o Lase Peroxide Sensy (0,20), enquanto que a maior com o Whiteness HP (1,50). Conclusão: Os géis clareadores Whiteness HP e Whiteness HP Maxx interferiram significativamente no aumento da temperatura intra-câmara pulpar durante o clareamento, sendo esta variação dependente do tipo de gel clareador empregado.

Etidronate from Medicine to Endodontics: effects of different irrigation regimes on root dentin roughness

An increase in dentin roughness, associated with surface composition, contributes to bacterial adherence in recontaminations. Surface roughness is also important for micromechanical interlocking of dental materials to dentin, and understanding the characteristics of the surface is essential to obtain the adhesion of root canal sealers that have different physico-chemical characteristics. OBJECTIVES: To evaluate the effects of sodium hypochlorite (NaOCl), ethylenediaminetetraacetic (EDTA), etidronic (HEBP), and citric acid (CA) associated with different irrigation regimens on root dentin roughness. MATERIAL AND METHODS: Forty-five root halves of anterior teeth were used. The root parts were sectioned in thirds, embedded in acrylic resin and polished to a standard surface roughness. Initially, the samples of each third were randomly assigned into 3 groups and treated as follows: G1 - saline solution (control); G2 - 5% NaOCl+18% HEBP mixed in equal parts; and G3 - 2.5% NaOCl. After initial measuments, the G3 samples were distributed into subgroups G4, G5 and G6, which were subjected to 17% EDTA, 10% CA and 9% HEBP, respectively. Following the new measuments, these groups received a final flush with 2.5% NaOCl, producing G7, G8 and G9. The dentin surface roughness (Ra) was determined before and after treatments using a profilometer. The Wilcoxon test (α<0.05) was used to compare the values before and after treatments, and the Friedman test (α<0.05) to detect any differences among root thirds. RESULTS: (i) NaOCl did not affect the surface roughness; (ii) there was a significant increase in roughness after the use of chelating agents (P<0.01); and (iii) only the G3 group showed a difference in surface roughness between apical third and other thirds of the teeth (P<0.0043). CONCLUSION: Only the irrigation regimens that used chelating agents altered the roughness of root dentin. .

One-Year Evaluation of a Simplified Ethanol-Wet Bonding Technique: A Randomized Clinical Trial

The objective of this randomized clinical trial was to evaluate the clinical performance of adhesive restorations using a three-step etch-and-rinse adhesive (TSER), a one-step self-etching adhesive (OSSE), and a simplified ethanol-wet bonding technique (EWBT) prior to the application of a composite resin in non-carious cervical lesions. Ninety-three restorations (31 for each group) were placed in 17 patients by a single operator. No cavity preparation was performed. After 6 and 12 months, the restorations were assessed by two previously trained examiners using modified Ryge criteria for retention (kappa=1.00) and marginal adaptation/staining (kappa=0.81), and the results were analyzed by Fisher's exact and Kruskal-Wallis tests, respectively. No significant differences were observed among groups at the 6- and 12-month time points for any of the assessed criteria (p≥0.05). The intra-group analysis performed by Cochran's test (for retention) and Wilcoxon test (for marginal adaptation/staining) revealed significant differences between the baseline/12-month time intervals in marginal adaptation in OSSE (p=0.0180) and in marginal staining in TSER (p=0.0117). The survival analysis for retention criteria performed using a log-rank test did not show significant differences (p>0.05). The restorations placed using the simplified EWBT performed equally well as the other adhesive strategies employed.

O objetivo deste ensaio clínico randomizado foi avaliar o comportamento clínico das restaurações adesivas, usando um adesivo convencional de três passos (CTP), um adesivo autocondicionante de um passo (AUP) e uma técnica simplificada da adesão úmida por etanol (AUET) antes da aplicação de uma resina composta em lesões cervicais não-cariosas. Noventa e três restaurações (31 para cada grupo) foram realizadas em 17 pacientes por um único operador. Nenhum preparo cavitário foi realizado. Depois de 6 e 12 meses, as restaurações foram avaliadas por 2 examinadores previamente treinados, utilizando critérios de Ryge modificados para retenção (kappa=1,00) e adaptação/manchamento marginal (kappa=0,81), e os resultados foram analisados pelos testes Exato de Fisher e Kruskal-Wallis, respectivamente. Não foram observadas diferenças significativas entre os grupos aos 6 e 12 meses para qualquer um dos critérios avaliados (p≥0,05). A análise intra-grupo feita pelos testes Q de Cochran (para retenção) e Wilcoxon (para adaptação/manchamento marginal) revelou diferenças significativas entre os intervalos de tempo baseline/12 meses para a adaptação marginal no AUP (p=0,0180) e manchamento marginal no CTP (p=0,0117). A análise de sobrevivência para o critério retenção realizada utilizando o teste de log-rank não apresentou diferenças significantes (p≥0,05). As restaurações feitas utilizando a técnica simplificada da adesão úmida por etanol comportaram-se igualmente às outras estratégias adesivas empregadas.

Avaliação da sensibilidade pós-operatória em restaurações diretas profundas utilizando sistemas adesivos autocondicionantes / Evaluation of postoperative sensitivity in deep direct restorations using self-etching adhesive systems

O propósito de presente estudo foi avaliar a sensibilidade pós-operatória (SPO) após 2 dias, 7 dias, 180 dias e 360 dias, em restaurações de dentes posteriores feitas com resina composta (Z-350, 3M-ESPE) associada a adesivos autocondicionantes. Foram realizadas 60 restaurações em 35 pacientes e os grupos experimentais foram assim delineados: GI= 20 cavidades tratadas com o sistema adesivo de três passos SBMU (3M-ESPE); GII= 20 cavidades tratadas com o sistema autocondicionante de dois passos Adper SE Plus (3M_ESPE); GIII= 20 cavidades tratadas com o sistema autocondicionante de um passo All Bond SE (BISCO). Após 48 horas, 7 dias, 180 dias e 360 dias, os pacientes foram chamados para avaliação da SPO. Inicialmente, o relato do paciente era considerado e classificado de zero a três, de acordo com critérios previamente estabelecidos. Posteriormente, teste clínico com frio era realizado e classificado de zero a dez, de acordo com a escala visual analógica modificada. Os resultados foram analisados pelos testes não paramétricos de Kruskall-Wallis, para comparar os diferentes tratamentos ao longo do tempo; e teste de Friedman, para analisar o comportamento de cada sistema ao longo dos períodos. Os testes estatísticos não mostraram diferenças significativas de SPO para os grupos testados em todos os períodos avaliados. Os resultados mostraram que, nesse caso, a SPO não foi influenciada pelos sistemas autocondicionantes.

Low shrinkage composite resins: influence on sealing ability in unfavorable C-factor cavities

The present investigation observed the sealing ability of low shrinkage composite resins in large and deep cavities, placed and photocured in one increment. Large, deep cavities (5.0 mm diameter and 2.5 mm deep) surrounded by enamel were prepared in bovine teeth, which were then divided into five groups. Groups 1, 2, 3 and 4: acid conditioning + Adper Single Bond (3M/ESPE, St Paul, MN, USA) and restoration with Aelite LS Posterior (BISCO Inc. Schaumburg, IL, USA) (G1); Filtek Z-350 (3M/ESPE,St Paul, MN, USA) (G2); Filtek Z-350 Flow (3M/ESPE, St Paul, MN, USA) (G3); Premisa (KERR Corporation, Orange, CA, USA) (G4). Group 5: Silorane Adhesive system (3M/ESPE, St Paul, MN, USA) + restoration with Filtek Low Shrinkage Posterior P90 (3M/ESPE, St Paul, MN, USA). After polymerization, the teeth were immersed in 0.5 percent basic fuchsine solution and immediately washed. Using the Imagetool Software, the extent of dye along the margins was calculated as a percentage of total perimeter. The restorations were then transversally sectioned and the depth of dye penetration was calculated in mm, using the same software. Kruskal-Wallis analysis for all groups showed no statistical differences for extent (p = 0.54) or depth (p = 0.8364) of dye penetration. According to this methodology, the so-called low shrinkage composite resins had the same sealing ability compared to regular and flowable nanocomposite materials.

Clinical evaluation of postoperative sensitivity using self-etching adhesives containing glutaraldehyde

The present clinical study aimed to assess the postoperative sensitivity (POS) after 48 hours and seven days in occlusal restorations bonded with three different adhesive systems, two of them containing glutaraldehyde. The restorative procedures were performed using the three-step etch-and-rinse Adper SBMP-Plus adhesive (SBMP), the two-step etch-and-rinse Gluma Comfort One Bond + Desensitizer adhesive (GC+D) and the all-in-one self-etching/priming I Bond (IB) adhesive, which also has glutaraldehyde in its formula. All cavities were restored with Filtek Supreme nanoparticle composite resin. After 48 hours and seven days the patients were recalled and the postoperative sensitivity evaluated. The data analyzed by non-parametric Friedman test showed no significant differences in POS among the three tested groups after 48 hours and seven days.

Cimentos autoadesivos: inter-relação dentina-cimento-pino / Self-adhesive luting cements: dentin-cement-post relationship

Os pinos pré-fabricados, cimentados nos condutos radiculares, são utilizados para aumentar a retenção do material de reconstrução e, em associação com a restauração indireta, aumentam a resistência do conjunto. O interior do conduto radicular é particularmente de difícil acesso e visualização. Assim, simplifica o protocolo de cimentação reduz a possibilidade de erros. Os cimentos autoadesivos, em virtude de sua fácil manipulação e aplicação, têm sido propostos para essa finalidade. No entanto, é necessário que a inter-relação desses materiais com a dentina e com o pino seja mais bem estudada e compreendida, bem como os aspectos relacionados à reação de polimerização. Sendo assim, este artigo tem como propósito apresentar informações das caracteristicas desse tipo de cimento, sua relação com a dentina e pino, com base em informações da literatura específica, bem como por meio de imagens obtidas com microscopia eletrônica de varredura (MEV).

Resinas compostas posteriores: análise de longevidade e comportamento clínico / Posterior composite restorations: analysis of longevity and clinical performance

A proposta deste estudo foi determinar como as resinas compostas inseridas em dentes posteriores têm se comportado clinicamente. A influência de fatores como higiene oral e risco à cárie, tamanho e localização da cavidade a ser restaurada, características físico-químicas das resinas compostas e a técnica operatória foram analisadas. As principais causas de falhas que determinam a substituição da restauração são a infiltração marginal e o desgaste. os critérios e o bom senso clínico para indicar uma restauração de resina composta em dentes posteriores são de importância fundamental para que elas tenham razoável longevidade. A otimização de resultados a longo prazo depende diretamente da análise crítica do profisional frente à cada situação clínica e dos cuidados com a técnica restauradora que ele emprega

Avaliação da infiltração marginal em restaurações com resina composta variando-se os métodos de fotoativação / Evaluation of the marginal leakage in restorations with composite, varying the light cure methods

O presente estudo se propôs a avaliar a infiltração marginal em restaurações realizadas pelas técnicas de fotoativação gradual e com máxima intensidade. Foram confeccionadas 32 cavidades de classe V, com margens em esmalte, dimensões ocluso-cervical de 2,0mm, mésio-distal de 2,0mm e profundidade de 1,5mm. As cavidades foram restauradas com o sistema restaurador Single Bond/Z-250 (3M do Brasil). Os dentes foram divididos em dois grupos. Os grupos diferiam entre si de acordo com a técnica de fotoativação da resina. Os resultados, mostraram que a técnica de fotoativação gradual apresentou índice de infiltração estatisticamente menor em relação à técnica de fotoativação com máxima intensidade

Avaliaçäo da variaçäo de pH e da permeabilidade da dentina cervical em dentes submetidos ao tratamento clareador / Evaluation of pH variation and cervical dentin permeability in teeth submitted to bleaching treatment

A reabsorçäo cervical externa da raiz é uma das desvantagens do procedimento clareador. Vários säo os mecanismos que podem ser responsáveis por desencadear esta reabsorçäo, dentre eles, a açäo química e física dos materiais utilizados, bem como a morfologia da junçäo amelocementária. Este trabalho teve como objetivo observar uma possível via de comunicaçäo entre a câmara pulpar e a superfície externa da raiz, medindo o pH e a infiltraçäo de corante na dentina cervical após o procedimento clareador. Realizou-se o tratamento endodôntico em 34 dentes incisivos permanentes. Os dentes foram divididos em 3 grupos experimentais de acordo com o nível do corte da obturaçäo e selamento da embocadura dos canais com cimento de ionômero de vidro. O clareamento foi realizado usando perborato de sódio e peróxido de hidrogênio a 30 por cento. As leituras do pH foram realizadas após 30min, 24h, 48h e 72h do início do procedimento. A seguir, os dentes foram imersos em fucsina básica a 0,5 por cento por 24h para determinarmos possíveis diferenças na permeabilidade da dentina cervical. Os resultados mostraram que o pH apresentou tendência a se modificar quando o corte da obturaçäo permaneceu na embocadura dos canais, bem como quando se removeram 2mm da obturaçäo e quando se selou a embocadura com cimento de ionômero de vidro. A permeabilidade dentinária aumentou nos 3 grupos experimentais, em comparaçäo com os dentes que compreenderam o grupo controle. Estas leves diferenças podem sugerir uma via de comunicaçäo entre a câmara pulpar e a superfície externa da raiz

Resistência à fratura de dentes despolpados tratados com agentes clareadores / The fracture strenght of extracted teeth with chemical agents

Verificou-se a resistência à fratura de dentes humanos extraídos, pré-molares hígidos, com abertura coronária e com curativos com agentes químicos e térmicos usados para a técnica de clareamento de dentes despolpados e escurecidos. Os resultados mostraram que os agentes químicos e térmicos usados nas técnicas de clareamento enfraquecem significativamente a estrutura dentária