Microleakage of "Bulk-Fill" Composite Resin for Class II Restorations Pretreated With CO2 Laser in Deciduous Molars: An In Vitro Study.

Introduction: Microleakage has been reported to cause dentin hypersensitivity because of the passage of bacteria and their products through the restoration-tooth interface and is one of the main reasons for replacement of restorations. CO2 laser can be used for treatment of dentin hypersensitivity. Thus, this study aimed to evaluate in vitro the microleakage in composite restorations following surface pretreatment with acid etching and CO2 laser. Methods: Twelve human caries-free primary molars were selected. Class II cavities were prepared on occlusal mesial and occlusal distal surfaces. Specimens were randomly divided into four groups (n=6): Group 1 (G1) - 37% phosphoric acid gel etching + Beautiful-Bulk Restorative - Giomer (Shofu Inc); Group 2 (G2) - 37% phosphoric acid gel etching + SDR Bulk-Fill Flow (Dentsply); Group 3 (G3) - CO2 laser irradiation + Beautiful-Bulk Restorative - Giomer (Shofu Inc); Group 4 (G4) - CO2 laser irradiation + SDR Bulk-Fill Flow (Dentsply). Surfaces were restored with bonding agent (Natural Bond DE, DFL). Specimens were cut longitudinally and immersed in 0.5% methylene blue solution for 4 hours. Microleakage scores were assessed under a magnifying glass at x3,5 and qualitatively analyzed by scanning electron microscope (SEM). Data were analyzed using nonparametric Wilcoxon test (P < 0.05). Results: Scores prevailed between 0 and 2, however, no statistically significant difference was found among the groups (P = 0.05). Conclusion: It could be concluded that all composite resins bulk fill did not show significant difference among them regarding microleakage using either CO2 laser or 37% phosphoric acid etching.

Remoción quimica-mecánica del tejido cariado en dientes permanentes: reporte de caso clínico / Chemo-mechanical caries removal in permanent tooth: case report

En odontopediatría, una de las principales dificultades que se presenta en la remoción del tejido dental cariado, es el manejo del paciente niño debido al miedo y a la ansiedad por el uso de anestesia e instrumentos rotatorios. A fin de resolver este problema, el método químico-mecánico para la eliminación del tejido cariado, es una alternativa conservadora y eficaz ya que evita el uso de anestésicos e instrumental rotatorio. Según estudios, este método es más aceptado por los pacientes comparado con el método tradicional. Este artículo tiene como objetivo presentar un caso clínico del uso del gel a base de papaína (Papacárie ®) para la eliminación químico-mecánica del tejido cariado en dientes permanentes.

anesthesia and rotating instruments. In order to solve this problem, the chemical-mechanical method for the elimination of the carious tissue, is a conservative and effective alternative since it avoids the use of anesthetics and rotary instruments. According to studies, this method is more accepted by patients compared to the traditional method. This paper aims to present a clinical case of the use of papain gel (Papacárie ®) for the chemical-mechanical removal of carious tissue in permanent teeth.

Electromyographic evaluation of a low-level laser protocol for the treatment of temporomandibular disorder: a randomized, controlled, blind trial.

[Purpose] Problems involving the temporomandibular joint and associated structures can lead to temporomandibular disorder (TMD). The aim of the present study was to evaluate muscle activity in individuals with a diagnosis of TMD before and after treatment with low-level laser therapy (LLLT) through the use of electromyography (EMG). [Subjects and Methods] Male and female individuals aged 14 to 23 years were evaluated. TMD was determined by a clinical examination and the administration of the Research Diagnostic Criteria for Temporomandibular Disorders, followed by the evaluation of sensitivity to palpation of the masseter and anterior temporal muscles as well as the EMG determination of muscle activity. The participants were randomly allocated to an active LLLT group (n=9) and sham group (n=7). Twelve sessions of LLLT were conducted using a wavelength of 780 nm, energy density of 25 J/cm2, power of 50 mW, power density of 1.25 W/cm2 and a 20-second exposure time or sham LLLT. Muscle activity was determined prior to treatment and after the last session. [Results] During the isometric evaluation of the masseter and anterior temporal muscles, an increase in the mean EMG signal was found in the group submitted to active LLLT. When evaluated individually, some participants in the active LLLT group demonstrated a reduction in muscle activity, but no significant differences were found in the mean EMG signal between the initial and final evaluations. [Conclusion] Further studies with a larger sample size are needed to confirm the present findings.

Influence of different test parameters on the microshear bond strength of two simplified etch-and-rinse adhesives.

PURPOSE: To evaluate the effect of different test parameters on the resin-dentin microshear bond strength (µSBS). MATERIALS AND METHODS: A 1.5-mm-thick dentin disk was prepared in each of 140 human molars. The disks were divided into five groups to test the following variables: time of adhesive light polymerization (n = 20), storage time (n = 40), bonding area (n = 40), Tygon tube removal (n = 20), and time of composite placement (n = 20). The adhesives were applied and each specimen was subjected to µSBS testing. All fractured specimens were observed with SEM. The data from each experiment were subjected to two-way ANOVA and Tukey's test (α = 0.05). RESULTS: The storage time, bonding area, and Tygon tube removal did not influence the µSBS. Higher µSBS values were found when empty Tygon tubes were filled after positioning and when the adhesive was light polymerized before Tygon tube placement (p < 0.05). CONCLUSIONS: Differences in test parameters affected the µSBS of adhesives, especially the time of adhesive light polymerization and composite placement.

Effect of sonic application mode on the resin-dentin bond strength and nanoleakage of simplified self-etch adhesive.

OBJECTIVES: This study aims to evaluate the effect of different application modes on the immediate and 6-month resin-dentin bond strength (µTBS) and nanoleakage in the hybrid and adhesive layers. MATERIALS AND METHODS: Three 1-step self-etch adhesives (One Coat 7.0 (OC), Clearfil S(3) Bond (CS), and FuturaBond NR (FB)) were applied on a flat superficial dentin surface of 30 human molars under manual mode or sonic vibration at a frequency of 170 Hz (SV). Composite build-ups were constructed incrementally; specimens were sectioned to obtain resin-dentin sticks with cross-sectional area of 0.8 mm(2) and tested in tension (0.5 mm/min) immediately (IM) or after 6 months (6M) of water storage. Two bonded sticks, from each tooth at each storage time, were immersed in a silver nitrate solution, photo-developed, and analyzed under scanning electron microscopy. The amount of nanoleakage was measured using the ImageTool 3.0 software. Data, from each adhesive, were analyzed by two-way ANOVA and Tukey's test (α = 0.05). RESULTS: OC and CS showed higher µTBS and lower nanoleakage in the IM period when applied with SV groups. For FB, no significant difference was observed between the two modes of application. All materials showed lower nanoleakage in the SV groups. Higher nanoleakage was observed after 6M for OC and FB. CONCLUSIONS: The sonic application mode at an oscillating frequency of 170 Hz can improve the resin-dentin µTBS, reduce the nanoleakage, and retard the degradation of the resin-dentin µTBS of Clearfil S(3) Bond and One Coat 7.0 adhesives. CLINICAL SIGNIFICANCE: Sonic application mode at an oscillating frequency of 170 Hz can be helpful and easy to use in dental practice to guaranty long-lasting restorations.

Effect of Two Microshear Test Devices on Bond Strength and Fracture Pattern in Primary Teeth

This in vitro study evaluated the influence of two devices for application of shear load in microshear tests on bond strength and fracture pattern of primary enamel and dentin. Eighty primary molars were selected and flat enamel (40 teeth sectioned mesio-distally) and dentin (40 teeth sectioned transversally) surfaces were obtained. Both surfaces were polished to standardize the smear layer. Two-step etch-and-rinse adhesive systems (Adper Single Bond and XP Bond) were used. Polyethylene tubes was placed over the bonded surfaces and filled with composite resin. The microshear testing was performed after storage in water (24 h/37 °C) using two devices for application of microshear loads: a notched rod (Bisco Shear Bond Tester) or a knife edge (Kratos Industrial Equipment). Failure modes were evaluated using a stereomicroscope. Bond strength data were subjected to ANOVA and chi-square test to compare the failure mode distributions (α=0.05). No significant differences were observed between the groups for dentin and enamel bond strength or fracture patterns (p>0.05). The predominant failure mode was adhesive/mixed. In conclusion, the devices for application of shear loads did not influence the bond strength values, regardless of adhesive system and substrate.

Este estudo in vitro avaliou a influência de dois dispositivos para aplicação de força de cisalhamento em testes de resistência de união ao microcisalhamento e no padrão de fratura em dentina e esmalte de dentes decíduos. Oitenta molares decíduos foram selecionados e superficies planas em esmalte (40 dentes seccionados no sentido mésio-distal) e dentina (40 dentes seccionados transversalmente) foram obtidas. Ambas as superficies foram abrasionadas para padronização da lama dentinária. Dois sistemas adesivos de condicionamento ácido prévio (Adper Single Bond e XP Bond) foram utilizados. Tubos de polietileno foram colocados sobre as superficies, nas quais já haviam sido aplicados os sistemas adesivos, e preenchidos com resina composta. O teste de resistência de união ao microcisalhamento foi realizado após armazenamento dos espécimes em água (24 h/37 °C) utilizando dois dispositivos para a aplicação das forças de cisalhamento: cisalha côncava (Bisco Shear Bond Tester) e cisalha plana (Kratos Industrial Equipment). O padrão de fratura foi avaliado usando estereomicroscópio. Os dados de resistência de união foram submetidos à ANOVA e o teste quiquadrado foi utilizado para comparar a distribuição dos padrões de fratura (α=0,05). Não foram observadas diferenças estatisticamente significantes entre os grupos, tanto para a resistência de união a dentina e esmalte quanto para o padrão de fratura (p>0,05). O modo de falha predominante foi adesiva/mista. Em conclusão, os dispositivos para aplicação de força de cisalhamento não influenciam os valores de resistência de união, independente do sistema adesivo e substrato.

Resistencia a la compresión de resinas compuestas a base de metacrilato y de silorano / Compressive strength of a silorane-based and a methacrylate-based composite resin

Objetivo: el objetivo de este estudio fue comparar la resistencia a la compresión de resinas compuestas a base de silorano y a base de metacrilato. Materiales y métodos: treinta muestras con formato de disco, fueron confeccionadas insertando las resinas, de forma incremental, en una matriz de aluminio (10 cm de diámetro x 15 mm de alto). El tiempo de fotoactivación de cada incremento fue de 20 segundos (Filtek P60, 3M ESPE) y 40 segundos (Filtek P90, 3M ESPE), utilizando una lámpara de luz halógena a 500 mW/cm2. LUego de ser almacenadas en agua destilada a 23 +- 2ºC y 50 +-5 por ciento de humedad relativa durante 40 horas, las muestras fueron sometidas al test de resistencia a la compresión, en una máquina de ensayos universal (1,3 mm/min). Los datos (en MPa) fueron analizados estadísticamente mediante ANOVA y prueba de Tukey (alfa=0,05). Resultados: los valores de resistencia a la compresión de P60 fueron estadísticamente superiores a los de P90 (P60=371,91 +- 58,76; P90=264,41+-30,33). Conclusión: las resinas compuestas a base de silorano presentaron los valores más bajos de resistencia a la compresión.

Resistencia a la compresión de resinas compuestas a base de metacrilato y de silorano / Compressive strength of a silorane-based and a methacrylate-based composite resin

Objetivo: el objetivo de este estudio fue comparar la resistencia a la compresión de resinas compuestas a base de silorano y a base de metacrilato. Materiales y métodos: treinta muestras con formato de disco, fueron confeccionadas insertando las resinas, de forma incremental, en una matriz de aluminio (10 cm de diámetro x 15 mm de alto). El tiempo de fotoactivación de cada incremento fue de 20 segundos (Filtek P60, 3M ESPE) y 40 segundos (Filtek P90, 3M ESPE), utilizando una lámpara de luz halógena a 500 mW/cm2. LUego de ser almacenadas en agua destilada a 23 +- 2ºC y 50 +-5 por ciento de humedad relativa durante 40 horas, las muestras fueron sometidas al test de resistencia a la compresión, en una máquina de ensayos universal (1,3 mm/min). Los datos (en MPa) fueron analizados estadísticamente mediante ANOVA y prueba de Tukey (alfa=0,05). Resultados: los valores de resistencia a la compresión de P60 fueron estadísticamente superiores a los de P90 (P60=371,91 +- 58,76; P90=264,41+-30,33). Conclusión: las resinas compuestas a base de silorano presentaron los valores más bajos de resistencia a la compresión.(AU)

Effect of the application time of phosphoric acid and self-etch adhesive systems to sclerotic dentin.

OBJECTIVES: To evaluate the effect of application time on the resin-dentin bond strength (µTBS) and etching pattern of adhesive systems applied on sclerotic dentine. MATERIAL AND METHODS: A total of forty-two bovine incisors had their roots removed. The 1-step self-etch GO (SDI), the 2-step self-etch Adper SE Bond (3MESPE) and the 35% phosphoric acid (3MESPE) from the 2-step etch-and-rinse Adper Single Bond 2 (3MESPE) were applied on the bovine incisal surfaces according to the manufacturer's instructions or duplicating the recommended conditioning time. After adhesive application, thirty teeth were restored with composite resin, stored for 24 h in distilled water at 37°C, and sectioned into resin-dentin bonded sticks (0.8 mm²) and tested according to the µTBS at 0.5 mm/min. The etching pattern of the remaining twelve teeth (n=4 for each material) was examined under scanning electron microscopy. Each tooth was divided into a buccal-to-lingual direction into three thirds, and each third randomly assigned to the groups: control (no treatment), according to the manufacturers' instructions and duplicating the recommended application time. The µTBS and the relative percentage of the tubule area opening were evaluated by two-way repeated measures ANOVA and Tukey's tests (α=0.05). RESULTS: The duplication of the conditioning time favored only the GO adhesive (p<0.05). Both application methods significantly increased the tubule area opening (p<0.05) compared to the controls. CONCLUSIONS: The efficacy of duplicating the conditioning time was only effective for the 1-step self-etch adhesive system tested.

Six-month evaluation of a resin/dentin interface created by methacrylate and silorane-based materials.

OBJECTIVES: This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. MATERIAL AND METHODS: The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. RESULTS: Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). CONCLUSIONS: The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

Tratamiento estético de manchas blancas de esmalte posortodoncia: asociación de blanqueamiento dental e infiltración resinosa / Esthetic treatment of postorthodontic enamel white spots: an association between tooth whitening and resin infiltration

Objetivo: describir la asociación entre blanqueamiento dental en el consultorio y la infiltración resinosa de manchas blancas originadas postratamiento ortodóntico. Caso clínico: el tratamiento estético de dientes anteriores se inició con el blanqueamiento con peróxido de hidrógeno en el consultorio. Después de siete días, las manchas blancas fueron infiltradas con resina de alta fluidez, con el fin de mejorar el aspecto estético. Conclusión: la asociación de las técnicas de blanqueamiento dental e infiltración resinosa permite corregir alteraciones cromáticas de un modo altamente conservador, con resultados satisfactorios

Tratamiento estético de manchas blancas de esmalte posortodoncia: asociación de blanqueamiento dental e infiltración resinosa / Esthetic treatment of postorthodontic enamel white spots: an association between tooth whitening and resin infiltration

Objetivo: describir la asociación entre blanqueamiento dental en el consultorio y la infiltración resinosa de manchas blancas originadas postratamiento ortodóntico. Caso clínico: el tratamiento estético de dientes anteriores se inició con el blanqueamiento con peróxido de hidrógeno en el consultorio. Después de siete días, las manchas blancas fueron infiltradas con resina de alta fluidez, con el fin de mejorar el aspecto estético. Conclusión: la asociación de las técnicas de blanqueamiento dental e infiltración resinosa permite corregir alteraciones cromáticas de un modo altamente conservador, con resultados satisfactorios (AU)

Effect of two microshear test devices on bond strength and fracture pattern in primary teeth.

This in vitro study evaluated the influence of two devices for application of shear load in microshear tests on bond strength and fracture pattern of primary enamel and dentin. Eighty primary molars were selected and flat enamel (40 teeth sectioned mesio-distally) and dentin (40 teeth sectioned transversally) surfaces were obtained. Both surfaces were polished to standardize the smear layer. Two-step etch-and-rinse adhesive systems (Adper Single Bond and XP Bond) were used. Polyethylene tubes was placed over the bonded surfaces and filled with composite resin. The microshear testing was performed after storage in water (24 h/37 °C) using two devices for application of microshear loads: a notched rod (Bisco Shear Bond Tester) or a knife edge (Kratos Industrial Equipment). Failure modes were evaluated using a stereomicroscope. Bond strength data were subjected to ANOVA and chi-square test to compare the failure mode distributions (α=0.05). No significant differences were observed between the groups for dentin and enamel bond strength or fracture patterns (p>0.05). The predominant failure mode was adhesive/mixed. In conclusion, the devices for application of shear loads did not influence the bond strength values, regardless of adhesive system and substrate.

Six-month evaluation of a resin/dentin interface created by methacrylate and silorane-based materials

Objectives: This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. Material and Methods: The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. Results: Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). Conclusions: The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

Associação de técnicas para diminuição da sensibilidade advinda do clareamento caseiro / Association of techniques for decreasing the sensibility coming from dental bleaching at home

A sensibilidade dentária associada ao clareamento dentário é a principal causa de desistência dos pacientes em relação à procura desse procedimento ou suspensão da continuidade do tratamento clareador. Para isso, tanto modificações químicas nos agentes clareadores, quanto estratégias clínicas têm sido propostas para eliminar e/ou controlar esse sintoma indesejado sem prejudicar o resultado estético final almejado. O presente trabalho relata um caso clínico onde várias estratégias foram utilizadas para eliminar a sensibilidade causada pelo clareamento caseiro com peróxido de carbamida 16 por cento. Ao final, o paciente ficou muito satisfeito com o resultado estético e não houve relato de ocorrência de sensibilidade durante o prOcedimento clareador

The main cause of patients withdrawal in relation to the demand for this procedure or suspension of bleaching is the dental sensitivity. For this, both modifcations in bleaching agents as clinical strategies have been proposed to eliminate and/or control this unwanted symptoms without affecting the fnal esthetic result. The present case report shows the association of several strategies to decrease the dental bleaching sensitivity caused by 16% peroxide carbamide gel for at-home bleaching. The results showed that the patient was very satisfed with the bleaching result and there was no record of sensitivity during the bleaching procedure.

Immediate bonding to bleached enamel treated with 10% sodium ascorbate gel: a case report with one-year follow-up.

It is generally not recommended that bonded restoration treatment should be carried out immediately after bleaching treatment. However, the use of antioxidants such as sodium ascorbate can be useful to avoid a waiting period. This article is a brief review about in vitro proposals to overcome low bond strength values to bleached dental surfaces. It shows a one-year follow-up case report of a young female presenting agenesis of maxillary lateral incisors reshaped with direct resin composite immediately after dental bleaching. Teeth were bleached with a combination of in-office and at-home whitening protocols, followed by the application of a 10% sodium ascorbate gel for one hour, to allow the immediate reshaping with direct resin composite restoration. After one year, the clinical performance of the restoration was successful. The use of sodium ascorbate gel can help the clinician to perform bonding procedures immediately after bleaching treatments.

Antioxidant activity by DPPH assay of potential solutions to be applied on bleached teeth.

The aim of this study was to assess, using the DPPH assay, the antioxidant activity of several substances that could be proposed to immediately revert the problems caused by bleaching procedures. The percentage of antioxidant activity (AA%) of 10% ascorbic acid solution (AAcidS), 10% ascorbic acid gel (AAcidG), 10% sodium ascorbate solution (SodAsS), 10% sodium ascorbate gel (SodAsG), 10% sodium bicarbonate (Bicarb), Neutralize(®) (NE), Desensibilize(®) (DES), catalase C-40 at 10 mg/mL (CAT), 10% alcohol solution of alpha-tocopherol (VitE), Listerine(®) (LIS), 0.12% chlorhexidine (CHX), Croton Lechleri (CL), 10 % aqueous solution of Uncaria Tomentosa (UT), artificial saliva (ArtS) and 0.05% sodium fluoride (NaF) was assessed in triplicate by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical assay. All substances exhibited antioxidant activity, except for CL. AAcidS, AAcidG and VitE exhibited the highest AA% (p<0.05). On the contrary, CHX, NE, LIS and NaF showed the lowest AA% (p<0.05). In conclusion, AAcidS, AAcidG, SodAsS, SodAsG and VitE presented the highest antioxidant activity among substances tested in this study. The DPPH assay provides an easy and rapid way to evaluate potential antioxidants.

Restauraciones directas con resina compuesta inmediatas al blanqueamiento dental: relato de un caso / Immediate resin composite restorations after dental bleaching: a case report

Objetivo. Relatar el uso de un gel antioxidante como paso intermedio para realizar restauraciones directas en resina compuesta inmediatas al blanqueamiento dental. Caso clínico. El tratamiento estético de los diente ántero-superiores e inferiores se inició con el blanqueamiento en el consultorio con peróxido de hidrógeno. Luego se aplicó sobre las superficies dentales con gel antioxidante de ascorbato de sodio al 10 por ciento durante 60 minutos para eliminar los residuos del gel blanqueador y se realizó el recontorno cosmético de los eis dientes antero-superiores con resinas compuestas directas, de este modo se evitó un tiempo de espera de aproximadamente 7 días después del blanqueamiento dental. Conclusiones. El uso de un gel de ascorbato de sodio al 10 por ciento permitió la realización de restauraciones directas en resina compuesta inmediatas al blanqueamiento dental, de forma segura.

Restauraciones directas con resina compuesta inmediatas al blanqueamiento dental: relato de un caso / Immediate resin composite restorations after dental bleaching: a case report

Objetivo. Relatar el uso de un gel antioxidante como paso intermedio para realizar restauraciones directas en resina compuesta inmediatas al blanqueamiento dental. Caso clínico. El tratamiento estético de los diente ántero-superiores e inferiores se inició con el blanqueamiento en el consultorio con peróxido de hidrógeno. Luego se aplicó sobre las superficies dentales con gel antioxidante de ascorbato de sodio al 10 por ciento durante 60 minutos para eliminar los residuos del gel blanqueador y se realizó el recontorno cosmético de los eis dientes antero-superiores con resinas compuestas directas, de este modo se evitó un tiempo de espera de aproximadamente 7 días después del blanqueamiento dental. Conclusiones. El uso de un gel de ascorbato de sodio al 10 por ciento permitió la realización de restauraciones directas en resina compuesta inmediatas al blanqueamiento dental, de forma segura.(AU)

Influence of ozone gas and ozonated water application to dentin and bonded interfaces on resin-dentin bond strength.

PURPOSE: To assess the influence of ozone gas and ozonated water application to prepared cavity and bonded interfaces on the resin/dentin bond strength of two-step etch-and-rinse adhesive systems (Adper Single Bond 2 [SB2] and XP-Bond [XP]). MATERIALS AND METHODS: Sixty extracted human third molars were sectioned perpendicularly to their long axes to expose flat occlusal dentin surfaces. In experiment 1, dentin was treated with ozone before the bonding procedure, while in experiment 2, ozone was applied to resin/dentin bonded interfaces. In experiment 1, dentin surfaces were treated either with ozone gas (2100 ppm), ozonated water (3.5 ppm), or distilled water for 120 s, and then bonded with SB2 or XP according to manufacturers' instructions. Hybrid composite buildups were incrementally constructed and the teeth were sectioned into resin-dentin sticks (0.8 mm2). In experiment 2, dentin surfaces were first bonded with SB2 or XP, composite buildups were constructed, and bonded sticks obtained. The sticks were treated with ozone as previously described. Bonded sticks were tested under tensile stress at 1 mm/min. Silver nitrate impregnation along the resin/dentin interfaces was also evaluated under SEM. RESULTS: Two-way ANOVA (adhesive and ozone treatment) detected no significant effect for the cross-product interaction and the main factors in the two experiments (p > 0.05), which was confirmed by the photomicrographs. CONCLUSION: Ozone gas and ozonated water used before the bonding procedure or on resin/dentin bonded interfaces have no deleterious effects on the bond strengths and interfaces.