Aim: To evaluate dentin permeability after pretreatment with 2.5% aqueous solution of titanium tetrafluoride (TiF4), followed by a self-etching universal adhesive system. Methods: Forty dentin discs (1.5 mm thick) were randomly divided into groups according to the application or non-application of a pretreatment, and the type of adhesive system to be tested (two-step self-etching/ Clearfil SE Bond/ Kuraray Medical, or universal adhesive system/ Single Bond Universal/ 3M ESPE). Both sides of the discs were conditioned with 37% phosphoric acid to remove the smear layer. The first hydraulic conductivity measurement (L1) was performed in a permeability machine, under 5 PSI pressure. The samples were sanded again to form a standardized smear layer. The teeth designated for pre-treatment with TiF4 received the TiF4 solutions applied actively for 60 seconds, and the adhesive systems were applied according to the manufacturer's instructions. Then, a new hydraulic conductivity measurement (L2) was performed for the purpose of calculating the hydraulic conductance at a later time, considering the water viscosity and the thickness of the specimen. The percentage (L) of dentin permeability after application of the adhesive system was obtained (L (%) = [(L1-L2) x100] / L1). The Mann-Whitney non-parametric test was applied. Results: There was no difference between the two adhesive systems, or between the groups with or without pretreatment, as regards dentin permeability (p>0.05). Conclusion: Pretreatment with 2.5% TiF4 did not influence dentin permeability, irrespective of the adhesive system used
Subject(s)Titanium , Dentin-Bonding Agents , Dentin Permeability , Fluorides
Objective: Evaluate the mechanical properties of experimental adhesive models with different photoinitiators (PI) polymerized by LED units of different power densities. Material and Methods: Three groups of adhesive models based on HEMA/BisGMA (45/55) were prepared in association with different PI combinations: G2 (control) 2 PI: 0.5% CQ, 0.5% EDMAB; G3 - 3 PI: 0.5% CQ; 0.5% DMAEMA, 0.5% DPIHP; G4 - 4 PI: 0.5% CQ; 0.5% EDMAB; 0.5% DMAEMA; 0.5% DPIHP. The three formulations were polymerized at two different LED power densities: 550 mW/cm2 and 1200 mW/cm2. The degree of conversion (DC) of adhesive monomers was monitored in situ through the FTIR for 600 s. Specimens were prepared for each formulation for analysis mong adhesive systems (G2
Objetivo: Avaliar as propriedades mecânicas de modelos adesivos experimentais com diferentes fotoiniciadores (PI) polimerizados por unidades de LED de diferentes densidades de energia. Material e Métodos: Três grupos de modelos adesivos baseados em HEMA/BisGMA (45/55) foram preparados em associação com diferentes combinações de PI: G2 (controle) 2 PI: 0,5% CQ, 0,5% EDMAB; G3 - 3PI: 0,5% CQ; 0,5% DMAEMA, 0,5% DPIHP; G4 - 4 PI: 0,5% CQ; 0,5% EDMAB; 0,5% DMAEMA; 0,5% DPIHP. As três formulações foram polimerizadas em duas densidades de potência de LED: 550 mW/cm2 e 1200 mW/cm2. O grau de conversão (DC) dos monômeros adesivos foi monitorado in situ através do FTIR durante 600 s. Amostras foram preparadas para cada formulação para análise de resistência à flexão (FS), módulo de elasticidade (ME), sorção (SOR) e solubilidade (SOL). Os dados foram submetidos aos testes ANOVA 2-fatores e Tukey (5%). Resultados: DC: houve diferença significativa entre os sistemas adesivos (G2
, Dentin-Bonding Agents
, Light-Curing of Dental Adhesives
, Photoinitiators, Dental
Aim: To evaluate the impact of a dual-cured adhesive system on the in situ degree of conversion (DC), bond strength (BS) and failure mode (FM) of adhesive interfaces in dentin cavities restored with a bulk-fill resin composite. Methods: 4-mm-deep dentin cavities with a 3.1 C-factor were created in 68 bovine incisors (n = 17 per group). The lightcured (Scotchbond™ Universal) or the dual-cured (Adper™ Scotchbond™ Multi-purpose Plus) adhesive system was applied to the cavities, which were then restored with a bulkfill resin composite (Filtek™ Bulk Fill). In situ DC analysis was performed by means of micro Raman spectroscopy at the top and bottom interfaces. Push-out BS was measured in a universal testing machine after 24-h or 6-month water storage. FM was determined with a stereomicroscope. Data of in situ DC and BS were analyzed by two-way analysis of variance (ANOVA) and Tukey test (p<0.05), while the FM was analyzed descriptively. Results: The groups that received the dual-cured adhesive system showed statistically higher in situ DC and BS than those that received the light-cured adhesive system. Cohesive failure mode was the most frequent in all conditions. Conclusion: In situ DC and BS were influenced by the curing strategies of the adhesive systems with better performance of the dual-cured material
Subject(s)Aging , Dentin-Bonding Agents , Composite Resins , Physical Phenomena , Polymerization
Abstract Using a bur multiple times to prepare dental structure may produce a smoother final surface on dentin than a new one. This superficial roughness may affect adhesion with resin-based materials by modifying the substrates' characteristics. The aim of this study was to evaluate the effect of multiple uses of diamond burs on dentin's superficial microroughness and bond strength with resin composite when using a self-etch adhesive. Diamond dental burs were used to simulate a preparation (dentin flat surface) on extracted third molars. Samples were distributed into groups according to burs' number of previous uses as follows: 0, 1, 5 and 10. Scanning electron microscopy images at 70x, 350x, and 1000x were used to illustrate burs' deformation. Each specimen's dentin microroughness was measured three times to compare between experimental groups and the micro-shear bond strength test (n=15) was performed for the 0 and 10 uses groups using a universal adhesive in a self- etching mode. Diamond crystals wear and dislodgements were evident among groups where the burs were used more times. As the number of uses increased the mean microroughness of the dentin surface decreased with significant differences between the 0 and 10 uses groups. No statistical differences between experimental groups resulted from bond strength tests. When using a universal adhesive in a self-etching mode, the number of previous uses of a diamond bur seems to have no significant effect on dentin/resin composite bond strength.
Resumen El uso de una fresa múltiples veces para preparar la estructura dental puede producir una superficie final más lisa en la dentina que una fresa nueva. Esta rugosidad superficial modifica las características del sustrato y puede afectar la adhesión con materiales resinosos. El objetivo de este estudio fue evaluar el efecto de los múltiples usos de las fresas de diamante sobre la micro rugosidad superficial de la dentina y la resistencia adhesiva con la resina compuesta cuando se utiliza un adhesivo de autograbado. Se utilizaron fresas dentales de diamante para simular una preparación (superficie plana de la dentina) en terceros molares extraídos. Las muestras se distribuyeron en grupos según el número de usos previos de las fresas de la siguiente manera: 0, 1, 5 y 10. Se utilizaron imágenes de microscopía electrónica de barrido a ×70, ×350 y ×1000 para ilustrar la deformación de las fresas. Se midió la micro rugosidad de la dentina de cada espécimen tres veces para comparar entre los grupos experimentales y se realizó la prueba de resistencia a la adhesión por micro cizallamiento (n=15) para los grupos de 0 y 10 usos utilizando un adhesivo universal en modo de autograbado. El desgaste de los cristales de diamante y los desprendimientos fueron evidentes entre los grupos en los que las fresas se utilizaron más veces. A medida que aumentaba el número de usos, la micro rugosidad media de la superficie de la dentina disminuyó, con diferencias significativas entre los grupos de 0 y 10 usos. En las pruebas de resistencia adhesiva no se observaron diferencias estadísticas entre los grupos experimentales. Cuando se utiliza un adhesivo universal en modo de autograbado, el número de usos previos de una fresa de diamante no parece tener un efecto significativo en la resistencia de la unión dentina/resina del composite.
Subject(s)Humans , Dentin-Bonding Agents/analysis , Shear Strength
Abstract: The purpose of this study was to compare the shear bond strength (SBS) of four resin-based composite materials to a silicate-based cement using a ''no-wait'' universal bond with self-etch (SE) and etch-and-rinse (ER) modes. Acrylic blocks (n=80, 2mm depth, 5mm diameter central hole) were prepared. The holes were filled with BiodentineTM (BD) and divided into 4 main groups (n=20) according to the composite resin type used: Group FZ250: FiltekTM Z250 Universal Restorative (microhybrid), Group SDR: SDR Plus U Bulk Fill Flowable (low-viscosity bulk-fill), Group FBP: FiltekTM Bulk Fill Posterior (high-viscosity bulk-fill), Group EF: EsFlow™ Universal Flowable Composite (nanohybrid). A 'no-wait' universal bond (Clearfil Universal Bond Quick) was used for bonding application. Then each group was divided into 2 subgroups according to the etching mode applied (ER and SE). SBSs were measured and stereomicroscope was used to identify the failure modes. Selected samples of fracture surfaces were imaged by SEM. Tukey's post-hoc and One-way ANOVA tests were used to analyze data. There were statistically significant differences among the composite groups (p 0.05). The SBS of BD to the resin composites depends on the composite type but application of the 'no-wait' universal bond in different etching modes is regardless of the SBS of BD to resin composites.
Resumen El objetivo de este estudio fue comparar la resistencia de adhesión al cizallamiento (SBS) de cuatro resinas con un cemento a base de silicato utilizando una adhesivo universal "no-wait" de autograbado (SE) y grabado y lavado (ER). Se prepararon bloques acrílicos (n=80, de 2mm de profundidad y un agujero central de 5mm de diámetro). Los agujeros se rellenaron con BiodentineTM (BD) y se dividieron en 4 grupos principales (n=20) según el tipo de resina compuesta utilizada: Grupo FZ250: FiltekTM Z250 Universal Restorative (microhíbrido), Grupo SDR: SDR Plus U Bulk Fill Flowable (bulk-fill de baja viscosidad), Grupo FBP: FiltekTM Bulk Fill Posterior (bulk-fill de alta viscosidad), Grupo EF: EsFlow™ Universal Flowable Composite (nanohíbrido). Para la aplicación de la adhesión se utilizó un adhesivo universal "no-wait" (Clearfil Universal Bond Quick). A continuación, cada grupo se dividió en 2 subgrupos según el modo de grabado aplicado (ER y SE). Se midieron los SBS y se utilizó el estereomicroscopio para identificar los modos de fallo. Las muestras seleccionadas de las superficies de fractura se analizaron mediante SEM. Se utilizaron las pruebas post-hoc de Tukey y ANOVA de una vía para analizar los datos. Hubo diferencias estadísticamente significativas entre los grupos de composites (p0,05). La SBS de la BD a los composites de resina depende del tipo de composite, pero la aplicación de la unión universal "no-wait" en los diferentes modos de grabado es independiente de la SBS de la BD a los composites de resina.
Subject(s)Humans , Dentin-Bonding Agents , Shear Strength , Turkey
Aim One of the reasons for the failure of adhesion in composite restorations and secondary caries may be the chemical irrigants used during the endodontic treatment. NaOCl is widely used for the biomechanical preparation of root canals due to its antimicrobial properties and capacity to dissolve organic material. In addition, another very effective decontamination solution is chlorhexidine 2%. There are few studies about the effect of root canal irrigation solutions on bond strength of universal adhesives therefore, in this study we have investigated the influence of CHX 2% and NaOCl 5.25% on micro-tensile bond strength of G-Premio Bond. Methods Twenty-four human teeth were randomly allocated to the following groups: G1, immersion in saline solution 0.9% for 30 minutes (control); G2, immersion in CHX 2% for 30 minutes; G3, immersion in NaOCl 5.25% for 30 minutes. After restoration, the dentin/resin interface was tested by micro-tensile bond strength. The surfaces morphology was analyzed by Scanning Electron Microscopy. Data were analyzed by ANOVA followed by Tukey test in SPSS software Version 24. Results There was a statistically significant difference between G3 and G1 (P < 0.05). There were no statistically significant differences among G1 and G2, G2 and G3. Conclusion Root canal irrigation with NaOCl 5.25% significantly reduced the micro-tensile bond strength in the G-Premio Bond at self-etch mode, but the use of CHX did not make a significant difference.
Subject(s)Sodium Hypochlorite , Chlorhexidine , Dentin-Bonding Agents , Endodontics
Introducción: se realizó una revisión bibliográfica con el objetivo de conocer, analizar y comparar los diferentes tipos de adhesivos de octava generación que se encuentran en el mercado y la diferencia que existe entre cada uno. Los adhesivos universales han demostrado mejoras en su resistencia, sobre todo en las técnicas de aplicación y en las propiedades de estos materiales, al mejorar la fuerza adhesiva para que el odontólogo pueda brindar tratamientos restaurativos exitosos. Objetivo: conocer, analizar y comparar los diferentes tipos de adhe- sivos de la octava generación empleados en odontología. Material y métodos: se realizó una búsqueda en las bases de datos electrónicas PubMed, BVS, Redalyc y ScienceDirect. Se utilizaron 32 artículos que cumplieron con los criterios predeterminados y la especificidad reque- rida para la pregunta de investigación. Conclusiones: se demostró que la tecnología cada día avanza, sobre todo en el área de los adhesivos, ya que éstos son de mucha utilidad en el día a día del odontólogo; es importante conocer cada uno de éstos, puesto que es un poco complejo seleccionar el correcto, mas no el uso. En la actualidad, existen diversas opciones por las que el odontólogo puede optar, es por ello que el pro- fesional debe estar capacitado sobre cada una de las diferentes marcas existentes y, de acuerdo al tratamiento, debe elegir cuál es mejor utilizar en una rehabilitación. Es importante para el odontólogo conocer estos materiales, ya que esto lo beneficiará al momento de llevar un plan de tratamiento restaurador (AU)
Introduction: a bibliographic review was carried out to learn about, analyze, and compare the different types of eighth-generation adhesives on the market and the difference between each one. Universal adhesives have demonstrated improvements in their resistance, especially in the application techniques and properties of these materials, improving the adhesive strength so that the dentist can provide successful restorative treatments. Objective: to know, analyze and compare the different types of eighth-generation adhesives used in dentistry. Material and methods: a search was made of the following electronic databases: PubMed, BVS, Redalyc, ScienceDirect. Finally, 32 articles that met the predetermined criteria and the specificity required for the research question were used. Conclusions: it was demonstrated that technology is advancing every day, especially in the area of adhesives since these are very useful in the daily life of the dentist. It is important to know each one of these since it is a little complex at the moment of selecting the correct one, but not the use. Currently, there are several options that the dentist can choose, which is why the professional must be trained on each of the various existing brands and according to the treatment which is the best to use at the time of rehabilitation. The dentist needs to know these materials since they will benefit him/her when carrying out a restorative treatment plan (AU)
Subject(s)Technology, Dental/trends , Dentin-Bonding Agents , Surface Properties , Acid Etching, Dental/methods , Compressive Strength , Dental Enamel/drug effects , Shear Strength , Dentin/drug effects , Nanoparticles , Flexural Strength
Los sistemas cementantes han mejorado notablemente, los objetivos que persiguen los nuevos cementos es que la adhesión sea duradera y conseguir siempre que sea posible una interface cerrada con un sellado perfecto. Se han podido desarrollar nuevas técnicas y nuevos materiales de cementación que han ido perfeccionando la unión del material restaurador al diente. En el presente estudio se compara la fuerza de adhesión a dentina de cementos de autograbado y cementos de grabado total para comprobar los efectos positivos en el grabado de la dentina. Para el estudio se utilizaron dos cementos a base de resina (RelyX U200 Clicker 3M y RelyX Ultimate 3M). Se encapsularon 40 molares en acrílico en dos grupos de 20 muestras para la aplicación de dos sistemas cementantes de autograbado (grupo 1) y de grabado total (grupo 2), respectivamente, se desgastaron hasta descubrir la dentina; siguiendo las especificaciones del fabricante se colocó el cemento en cada grupo, y después se sometieron a pruebas de cizalla en una máquina de ensayo universal Instron. La medida expresada en megapascales (MPa) fue: grupo 1 = 7.5569 y grupo 2 = 12.6444. En este caso fueron analizados dos grupos, tomándose la primera significancia bilateral. Se realiza la prueba en t de Student, con 95% de intervalo de confianza en la diferencia, demostrando así que el cemento RelyX Ultimate 3M tiene mayor fuerza de adhesión que el cemento RelyX U200 Clicker 3M. Nuestra investigación fue factible y llegamos a nuestro propósito, en el cual comprobamos la mayor adhesión de cementos de grabado total, los cuales son sometidos a un previo tratamiento del diente (AU)
Subject(s)Humans , Adolescent , Adult , Acid Etching, Dental , Cementation , Dentin-Bonding Agents , Resin Cements , Shear Strength , Tensile Strength , Data Interpretation, Statistical , Dentin/drug effects
Abstract Objective: To evaluate the microleakage at the junction between amalgam-composite resin restorations using different bonding systems. Material and Methods: In this in-vitro study, standard class II cavities were prepared on 40 human maxillary premolars. The axial and gingival floor depths of the cavities were 2 mm and 1 mm below (cementoenamel junction), respectively. The samples were divided into 4 groups (n = 10). In all groups, a layer of 1-mm thick amalgam was used as a coating for the initial part of the gingival floor. In group 1, no bonding system was used for amalgam restoration. In group 2, G-Premio Bond was applied. G-Premio bond + alloy primer and single bond + alloy primer were used in group 3 and group 4, respectively. The rest of the cavities in all groups were then repaired using FiltekZ250 composite. The samples were thermocycled at 500 rpm and immersed in 1% methylene blue solution for 24 hours to allow dye penetration. Once cut, the samples were placed under a stereomicroscope (40X) to determine the microleakage rate. Data analysis was carried out using post-hoc and Chi-square tests (p<0.05). Results: The highest and lowest microleakage rate was related to groups 1 and 3, respectively. There was a significant difference between groups (1,2) and (1,3), and (1,4), and groups (2,3) (p<0.05). Conclusion: The use of alloy primer and bonding could reduce the microleakage between the two restorations (AU).
Subject(s)Humans , Dentin-Bonding Agents , Composite Resins , Dental Leakage , Dental Restoration, Permanent , In Vitro Techniques/methods , Chi-Square Distribution , Dental Bonding
Abstract Objective: To evaluate and compare the shear bond strengths (SBS) and bracket failure rates (BFR) of orthodontic brackets bonded with Light Cure adhesive against those bonded with Self Cure adhesive. Material and Methods: The study had in vitro and in vivo parts. In the in vitro part to determine SBS of Light Bond(LB)(R) and Rely.a.Bond(RB)(R) adhesives used in bonding brackets to 88 extracted teeth, each adhesive type was used to bond 44 brackets. The clinical study was conducted to determine the BFR of the LB(R) and RB(R) adhesives by bonding 256 teeth using each adhesive type. A standardized bonding procedure was followed in both the in vitro and in vivo parts of the study. Data were analyzed using frequency, percentage, mean, independent t-test, chi-square, and Pearson Correlation statistics. A p-value of ≤ 0.05 was considered significant. SPSS version 21.0 was used to analyze the data generated. Results: There was a significantly higher mean SBS 10.6MPa for LB(R) adhesive than the 7.0MPa of the RB(R) adhesive. In the in vivo study, (LB)(R) had a greater but not significant BFR of 9.0% than RB(R) (8.0%). No significant relationship existed between the SBS of either adhesive type (as determined in vitro) and their BFR in vivo. Conclusion: Higher SBS of LB(R) did not translate to less BFR in the clinic, nor did a lower SBS of RB(R) translate to more BFR in the clinic (AU).
Subject(s)Humans , Dental Bonding/instrumentation , Orthodontic Brackets , Dentin-Bonding Agents , Shear Strength , In Vitro Techniques/methods , Chi-Square Distribution
Objective: The current study aimed to evaluate the effect of diode laser irradiation (980 nm) and warm air drying (50°C) on shear bond strength between Lithium di-silicate (IPS e.max; Ivoclar) and human dentin using both (Etch & Rinse) adhesive, Adper™ Single Bond 2 (3M ESPE) and (Self-etch) adhesive, Single Bond UniversalTM(3M ESPE) before adhesive polymerization. Material and Methods: 54 sound lower molars were sectioned to obtain flat dentinal surfaces. Specimens were divided into 2 equal groups (n=27): Group 1 (ER) and Group 2 (SE) according to bonding approach. Each subgroup was subdivided according to dentin surface treatment into 3 equal subgroups (n=9): Control (Co), Diode laser irradiation (L) and Warm air drying (W). All specimens were adhesively cemented to IPS e.max® CAD discs using RelyX™ Ultimate Clicker™(3M ESPE) resin cement. Samples were then subjected to pre-loading in a thermodynamic manner. All samples were tested for shear bond strength using computer-controlled material testing machine. Data analysis was performed using two-way (ANOVA) (p< 0.05) followed by pair-wise Tukey's post-hoc tests. Results: In (SE) group, the subgroup (W) had the highest shear bond strength values followed by (Co) subgroup and the least was (L) subgroup with statistically significant difference. As for (ER) group, the subgroup (W) had the highest shear bond strength values followed by (Co) subgroup and the least was (L) subgroup with no statistically significant difference. Conclusion: Warm air drying for (SE) bonding approach increased shear bond strength of Lithium di-silicate to human dentin and can be introduced as a new effective protocol.(AU)
Objetivo: o objetivo do estudo atual é avaliar o efeito da radiação do laser de diodo (980nm) e secagem de ar quente (50°C) na resistência ao cisalhamento entre dissilicati de Lítio (IPS e.max; Ivoclar) e a dentina humana usando ambos modelos de adesivos (condicionamento total) Adper™ Single Bond e (auto-condicionante) Single Bond Universal™ (3M ESPE), Single Bond UniversalTM (3M ESPE) antes da fotopolimerização. Material e Métodos: 54 segundos molares inferiores foram selecionados para obter superfícies dentinárias planas. Os espécimes foram divididos em 2 grupos iguais (n=27): grupo 1 (ER) e grupo 2 (SE) de acordo com protocolo de adesividade. Cada grupo foi subdividido de acordo com o tratamento de superfície dentro de 3 subgrupos iguais (n=9): Controle (co), irradiação com laser de diodo (L) e secagem com ar quente (W). Todos os espécimes foram adesivamente cimentados a discos de IPS emax CAD usando RelyX Ultimate Clicker (3M ESPE) cimento resinoso. As amostras foram então submetidas a pré-carregamento de forma termodinâmica. Todas as amostras foram testadas para resistência a cisalhamento usando máquina de teste de materiais controlados por computador. A análise de dados foi realizada usando ANOVA dois fatores (p<0.05) seguindo por testes de Tukey pareado como test post-hoc. Resultados: No grupo (SE), o subgrupo (W) apresentou maiores valores de resistência ao cisalhamento seguindo o subgrupo (Co) é o menor foi o subgrupo (L) com diferença estatisticamente significativa. Já para o grupo (Er), o subgrupo (W) apresentou os maiores valores de resistência ao cisalhamento seguido do grupo (Co) e o menor foi o subgrupo (L) sem diferença estatisticamente significante. Conclusão: a secagem com ar quente para a abordagem de adesividade (Se) aumentou a resistência ao cisalhamento do dissilicato de lítio à dentina humana e poderia ser introduzido como um novo e eficaz protocolo(AU)
Subject(s)Humans , Dentin-Bonding Agents , Shear Strength , Dentin , Lasers, Solid-State
Objective: The aim of this study was to evaluate the effect of STMP as biomimetic analog of dentin matrix on the dentin bond strength submitted to artificial cariogenic challenge over time. Material and Methods: The total number of teeth used in the experiment was 60 teeth, which were divided into 6 groups (n = 10). Of these total amount, 10 teeth were not submitted to the artificial cariogenic challenge (ACC), serving as control group (Sound Dentin - SD) while the other 50 were submitted to an ACC (7d/37ºC), being treated with treatment solutions according to each group: SD- deionized water/sound dentin, CD- deionized water/ artificial caries dentin, GIII- STMP, GIV- STMP + Ca(OH)2, GV- STMP + NaF, and GVI- NaF. After treatments (24h), the specimens were restored (Adper Single Bond Universal + Filtek Z250), to obtain resindentin sticks with a cross sectional area of 0.8mm2, approximately. Two-third of these sticks were stored in artificial saliva (37°C) for analyzes after 6 and 12 months. The 1/3 remains were subjected to µTBS test (baseline). Data were analyzed by two-way ANOVA and Tukey tests (p<0.05). Results: In general, the highest µTBS values were obtained in sound condition (SD), while the artificial caries condition (CD) determined minimum values. Groups treated with NaF (with or without STMP- GV and GVI) were not able to improve adhesion over time. Only the use of STMP + Ca(OH)2(GIV) improved the µTBS compared to the others caries-challenged dentin after 1 year. The adhesive failure pattern was predominant in all time. Conclusion: The use of the STMP associated with Ca(OH)2 seems to be a viable therapeutic strategy conciliating the biomimetizing capacity to the adhesive process satisfactorily even its performance is not superior to initial condition (AU)
Objetivo: O objetivo deste estudo foi avaliar o efeito do STMP como análogo biomimético da matriz dentinária na resistência de união à dentina submetida a desafio cariogênico artificial ao longo do tempo. Material e Métodos:foram utilizados um total de 60 dentes neste experimento, os quais foram divididos em 6 grupos (n = 10). Desse total, 10 dentes não foram submetidos ao desafio cariogênico artificial (DCA), servindo como grupo controle (Dentina Hígida - DH) enquanto os outros 50 foram submetidos ao DCA (7d / 37ºC), sendo tratados com soluções de tratamento específicas para cada grupo: DH- água deionizada / dentina hígida, DC- água deionizada / dentina submetida ao DCA, GIII- STMP, GIV- STMP + Ca(OH)2, GV- STMP + NaF e GVI- NaF. Após os tratamentos (24h), os corpos-de-prova foram restaurados (Adper Single Bond Universal + Filtek Z250), para obtenção de palitos de resina-dentina com área transversal de aproximadamente 0,8mm2. Dois terços desses palitos foram armazenados em saliva artificial (37°C) para análises após 6 e 12 meses. Os outros 1/3 foram submetidos ao teste µTBS (baseline). Os dados foram analisados por ANOVA a dois fatores e testes de Tukey (p <0,05). Resultados:Em geral, os maiores valores de µTBS foram obtidos em condição hígidas (DH), enquanto a condição subtmetidas ao DCA determinou os menores valores. Os grupos tratados com NaF (com ou sem STMP associado -GV e GVI) não foram capazes de melhorar a resistência de união, ao longo do tempo. Somente o uso de STMP + Ca (OH)2(GIV) melhorou o µTBS em comparação com as outras condições desafiadas por cárie após 1 ano. O padrão de falha adesiva foi predominante em todos os tempos. Conclusão: O uso do STMP associado ao Ca (OH)2 parece ser uma estratégia terapêutica viável conciliando a capacidade biomimetizante ao processo adesivo de forma satisfatória mesmo que seu desempenho não seja superior à condição inicial.(AU)
Subject(s)Humans , Protease Inhibitors , Dentin-Bonding Agents , Dentin
Objective: To evaluate the ability of different separating mediums to prevent adhesion between provisional restorations and hybridized dentin surfaces when used with the Immediate Dentin Sealing technique (IDS). Material and Methods: 120 extracted human teeth 40 premolars and 80 molars were selected to integrate acrylics samples separated into 4 different groups (n=10) according to the separating medium used for IDS protection. Forty samples were made of three teeth mounted in a self-cure acrylic resin block (Jet, Classic, São Paulo, Brazil) arranged side by side, simulating the positioning and proximal contacts present in the dental arch between the second premolar, first molar and second molar. A standard dental preparation for ultra-thin occlusal veneer was performed and complete occlusal dentin exposure was achieved by selective removal of the occlusal enamel with a high-speed conical round burr (Code: 1801.4138 FG, KG Sorensen, Medical Burs Ind. e Com. de Pontas e Brocas Cirúrgicas Ltda, São Paulo, Brazil). Dentin hybridization were performed on the control group and 3 different groups of separating mediums (n=10): PCcommercial provisional separating agent (Pro-V Coat, Bisco, Schaumburg, USA); GGglycerin gel (K-Y Gel; Johnson & Johnson Industry and Commerce LTDA, São Paulo, Brazil); PJpetroleum jelly (Rioquímica, São Paulo, Brazil). Provisionalization were manufactured on the prepared teeth. After 2 weeks, the tensile test was performed, and the analysis of the failure pattern was performed by 3D laser confocal microscopy and Scanning Electron Microscopy (SEM). The data were analyzed with the 1-way ANOVA and the Tukey test (α = 0.05). Results: Significantly lower tensile strength values were found for the commercial provisional separating agent (30.39 ± 10.01 N) compared to others (p < 0.05). Conclusion: The commercial provisional separating agent showed greater effectiveness on protecting hybridized dentin against the provisional restorations (AU)
Objetivo: Avaliar a capacidade de diferentes agentes isolantes em prevenir a adesão entre as restaurações provisórias e a superfícies de dentina hibridizadas quando usados com a técnica do Selamento Dentinário Imediato (IDS). Material e Métodos: 120 dentes humanos extraídos - 40 pré-molares e 80 molares - foram selecionados para integrar as amostras de acrílico divididas em 4 grupos diferentes (n = 10) de acordo com o meio de separação usado para proteção IDS. Foram confeccionadas 40 amostras de três dentes montados em um bloco de resina acrílica autopolimerizável (Jet, Classic, São Paulo, Brasil) dispostos lado a lado, simulando o posicionamento e os contatos proximais presentes na arcada dentária entre o segundo pré-molar, primeiro molar e segundo molar. Um preparo dentário padrão para laminado oclusal ultrafino foi realizado e a exposição completa da dentina oclusal foi obtida pela remoção seletiva do esmalte oclusal com uma broca cônica arredondada de alta rotação (Código: 1801.4138 FG, KG Sorensen, Medical Burs Ind. E Com. de Pontas e Brocas Cirúrgicas Ltda, São Paulo, Brasil). A hibridização da dentina foi realizada no grupo controle e em 3 grupos diferentes de agentes isolantes (n = 10): PC - agente de separação provisório comercial (Pro-V Coat, Bisco, Schaumburg, EUA); GG gel de glicerina (K-Y Gel; Johnson & Johnson Industry and Commerce LTDA, São Paulo, Brasil); PJ vaselina (Rioquímica, São Paulo, Brasil). As restaurações provisórias foram fabricadas nos dentes preparados. Após 2 semanas, foi realizado o teste de tração, e a análise do padrão de falha foi realizada por microscopia confocal a laser 3D e Microscopia Eletrônica de Varredura (MEV). Os dados foram analisados com a ANOVA de 1 fator e o teste de Tukey (α = 0,05). Resultados: Valores de resistência à tração significativamente menores foram encontrados para o agente separador provisório comercial (30,39 ± 10,01 N) em comparação com os demais (p < 0,05). Conclusão: O agente separador provisório comercial mostrou maior eficácia para a proteção da dentina hibridizada contra as restaurações provisórias (AU)
Subject(s)Humans , Dentin-Bonding Agents , Dental Restoration, Temporary , Dentin
Objective: The aim of this study was to evaluate the effectiveness of different adhesives on the shear bond strength (SBS) of brackets bonded to different ceramic materials. Material and Methods: Fifty disk-shaped specimens were produced from lithium disilicate (IPS e.max CAD) and monolithic zirconia (Cercon) materials. Each specimen was polished with a three-step diamond polishing system. The polished ceramic surfaces were conditioned with universal bonding resin (Assure Plus) without pre-treatment, except for two specimens. Central brackets were bonded onto different ceramic specimens with different adhesives as follows: group 1: conventional adhesive onto the lithium disilicate; group 2: one-step adhesive onto the lithium disilicate; group 3: conventional adhesive onto the monolithic zirconia; group 4: one-step adhesive onto the monolithic zirconia. After thermal cycling, the specimens were subjected to the SBS test. The adhesive remnant index (ARI) scores were also recorded to evaluate bond failure type. KruskalWallis and Mann-Whitney U tests were used for statistical analysis. Results: There were statistically significant differences among the SBS values (pË0.05). The monolithic zirconia group with universal bonding resin and conventional orthodontic adhesive demonstrated the highest SBS value (6.34 MPa) and ARI scores. The lithium disilicate group showed the lowest SBS value (2.17 MPa) with the same protocol. No adhesive remained on the lithium disilicate specimens. Conclusion: One-step adhesive and universal bonding resin combination should not be considered as an alternative for lithium disilicate and monolithic zirconia restorations. Conventional adhesive and universal bonding resin application can be effective on non-pretreated ceramic surfaces during orthodontic bonding (AU)
Objetivo: o objetivo deste estudo foi avaliar a eficácia de diferentes adesivos na resistência ao cisalhamento (SBS) de bráquetes colados a diferentes materiais cerâmicos. Material e métodos: Cinquenta espécimes em forma de disco foram produzidos a partir de materiais de dissilicato de lítio (IPS e.max CAD) e zircônia monolítica (Cercon). Cada amostra foi polida com um sistema de polimento de diamante de três passos. As superfícies cerâmicas polidas foram condicionadas com resina de ligação universal (Assure Plus) sem pré-tratamento, exceto para dois corpos-de-prova. Bráquetes centrais foram colados em diferentes corpos de prova cerâmicos com diferentes adesivos da seguinte forma: grupo 1: adesivo convencional sobre dissilicato de lítio; grupo 2: adesivo de uma etapa sobre o dissilicato de lítio; grupo 3: adesivo convencional sobre zircônia monolítica; grupo 4: adesivo de uma etapa sobre a zircônia monolítica. Após a ciclagem térmica, os corpos-de-prova foram submetidos ao teste SBS. Os escores do índice de remanescente adesivo (ARI) também foram registrados para avaliar o tipo de falha de adesão. Os testes U de Kruskal-Wallis e Mann-Whitney foram usados para análise estatística. Resultados: Houve diferenças estatisticamente significativas entre os valores de SBS (pË0,05). O grupo de zircônia monolítica com resina de colagem universal e adesivo ortodôntico convencional demonstrou o maior valor de SBS (6,34 MPa) e escores de ARI. O grupo de dissilicato de lítio apresentou o menor valor de SBS (2,17 MPa) com o mesmo protocolo. Nenhum adesivo permaneceu nas amostras de dissilicato de lítio. Conclusão: A combinação de adesivo de uma etapa e resina de ligação universal não deve ser considerada como uma alternativa para restaurações de dissilicato de lítio e zircônia monolítica. A aplicação de adesivo convencional e resina de colagem universal podem ser eficazes em superfícies de cerâmica não pré-tratadas durante a colagem ortodôntica (AU)
Subject(s)Resins, Synthetic , Orthodontic Brackets , Dentin-Bonding Agents , Shear Strength
A cimentação de pinos de fibra de vidro à dentina intrarradicular, principalmente no terço apical, continua sendo um desafio na odontologia. O objetivo desse estudo foi avaliar a influência do controle de umidade com etanol na resistência de união de pinos de fibra de vidro em diferentes terços de dentina intrarradicular, 24 horas e 6 meses após o processo de cimentação adesiva. Sessenta e quatro incisivos bovinos extraídos foram submetidos ao tratamento endodôntico e divididos em dois grupos, de acordo com o tipo de controle de umidade (técnica convencional e alcoólica). Cada grupo foi dividido em 4 subgrupos (n=8) de acordo com a cimentação: RXU: Single bond Universal + RelyX Ultimate; PNV: primer de dentes Panavia V5 + Panavia V5; U200: RelyX U200; SET: Set PP. A resistência de união do pushout foi medida em diferentes áreas da interface entre o pino e a superfície radicular, 24 horas e 6 meses após o procedimento de união. Os dados foram submetidos ao teste de Bonferroni (α = 0,05). Os menores valores de resistência de união foram encontrados para o grupo SET, com diferença estatisticamente significante entre os demais grupos para os terços cervical e médio. Os maiores valores de resistência de união foram encontrados para o grupo PNV com diferença estatisticamente significante para os demais grupos nos terços médio e apical em 24 horas. Avaliando os diferentes terços, em geral, os maiores valores de resistência de união foram encontrados para o terço cervical. O grupo PNV apresentou maiores valores de resistência de união para os terços cervical e médio, sem diferença estatisticamente significante entre eles. Quanto ao tipo de controle de umidade, pode-se observar que não há diferença estatisticamente significativa para o grupo PNV às 24 horas, U200 e SET aos 6 meses. Na comparação entre os tempos (24 horas e 6 meses), em geral, os valores de resistência de união diminuíram após o armazenamento. Diferenças significativas com menores valores foram observadas após o tempo de seis meses nos valores de envelhecimento para a resistência de união. Por meio de um microscópio óptico e um aparelho de microscopia eletrônica de varredura o padrão de fratura na interface adesiva foi caracterizado.
Cementation of fiberglass posts to intraradical dentin, especially in the apical third, remains a challenge in dentistry. The study was to evaluate the influence of moisture control with ethanol on the bond strength of fiberglass posts in different thirds of intraradicular dentin, 24 hours and 6 months after the adhesive cementation process. Sixty-four extracted bovine incisors were endodontically protected and divided into two groups, according to the type of moisture control (conventional and alcoholic technique). Each group was divided into 4 subgroups (n=8) according to cementation: RXU: Single bond Universal + RelyX Ultimate; PNV: Panavia V5 tooth primer + Panavia V5; U200: RelyX U200; SET: Set PP. The pushout bond strength was measured in different areas of the interface between the post and the root surface, 24 hours and 6 months after the bonding procedure. The data were confirmed by the Bonferroni test (α = 0.05). The lowest bond strength values were found for the SET group, with a statistically significant difference between the other groups for the cervical and middle thirds. The highest bond strength values were found for the PNV group, with a statistically significant difference for the other groups in the middle and apical thirds at 24 hours. Evaluating the different thirds, in general, the highest bond strength values were found for the cervical third. The PNV group showed higher bond strength values for the cervical and middle thirds, with no statistically significant difference between them. As for the type of humidity control, it can be observed that there is no statistically significant difference for the PNV group at 24 hours, U200 and SET at 6 months. In the comparison between times (24 hours and 6 months), in general, the bond strength values decreased after storage. Minor elevation differences with values were observed after the six-month time in the ageing values for bond strength. Using an optical microscope and a scanning electron microscopy device, the fracture pattern at the adhesive interface was characterized.
Subject(s)Dentin-Bonding Agents , Dental Cements , Dental Pins , Dentin
OBJECTIVES@#Root canal therapy is the most effective and common method for pulpitis and periapical periodontitis. During the root canal preparation, chemical irrigation plays a key role. However, sodium hypochlorite (NaOCl), the widely used irrigation fluid, may impact the bonding strength between dentin and restorative material meanwhile sterilization and dissolving. Therefore, it's important to explore the influence of NaOCl on the adhesion between dentin and restoration materials to ensure clinical efficacy. This study aims to explore the effect of NaOCl on dentine adhesion and evaluate the effect of dentine adhesion induced by sodium erythorbate (ERY), and to provide clinical guidance on dentin bonding after root canal therapy.@*METHODS@#Seventy freshly complete extracted human third molars aged 18-33 years old, without caries and restorations were selected. A diamond saw was used under running water to achieve dentine fragments which were divided into 10 groups with 14 fragments in each group: 2 control [deionized water (DW)±10% ERY] and 8 experimental groups (0.5%, 1%, 2.5%, and 5.25% NaOCl±10% ERY). The dentine specimens in the control group (treated with DW) and the experimental groups (treated with 0.5% NaOCl, 1% NaOCl, 2.5% NaOCl, and 5.25% NaOCl) were immersed for 20 min using corresponding solutions which were renewed every 5 min. The other 5 groups were immersed in 10% ERY for 5 min after an initial washing with DW for 1 min. Then, we selected 4 dentine fragments from all 14 fragments in each group and the numbers and diameters of opening dentinal tubules were observed under scanning electron microscope (SEM). The other 10 dentine fragments from each group were used to make adhesive samples by using self-etch adhesive wand composite resin. All the above adhesive samples were sectioned perpendicular to the bonded interface into 20 slabs with a cross-sectional area of 1 mm×1 mm using a diamond saw under the cooling water, and then the morphology of 10 slabs in each group's bonding interface was observed from aspects of formation of resin tags, depth of tags in dentin, and formation of hybrid layer under SEM. The other 10 slabs of each group's microtensile bond strength and failure modes were also analyzed.@*RESULTS@#Among the 0.5% NaOCl, 1% NaOCl, 2.5% NaOCl, and 5.25% NaOCl groups, the number and diameter of patent dentinal tubules gradually increased with the rise of concentration of NaOCl solution (all P<0.05). Among the DW, 0.5% NaOCl, 1% NaOCl, 2.5% NaOCl, and 5.25% NaOCl groups, the number and diameter of patent dentinal tubules increased after using ERY, but without significant difference (all P>0.05). Among the DW, 0.5% NaOCl, 1% NaOCl, and 2.5% NaOCl groups, the scores of formation of resin tags under SEM gradually increased with the increase of concentration of NaOCl solution, while the score in the 5.25% NaOCl group decreased significantly compared with the score of the 2.5% NaOCl group (P<0.05). There was no significant difference between using 10% ERY groups and without using 10% ERY groups (all P>0.05). The scores of length of the tags under SEM in the 5.25% NaOCl group was significantly higher than the scores of DW, 0.5% NaOCl, and 1% NaOCl groups (all P<0.05), and it was also higher than the score of the 2.5% NaOCl group, but without significant difference (P>0.05). There was no significant difference between using 10% ERY groups and without using 10% ERY groups (P>0.05). The scores of formation of hybrid layer under SEM in the 2.5% NaOCl and 5.25% NaOCl groups significantly decreased compared with the score of the DW group (all P<0.05). There were significant differences between the 2.5% NaOCl±10% ERY groups and between the 5.25% NaOCl±10% ERY groups (all P<0.05). Microtensile bond strength was greater in the 0.5% NaOCl, 1% NaOCl, and 2.5% NaOCl groups, but lower in the 5.25% NaOCl group than that in the DW group (all P<0.05). There were significant differences between the 2.5% NaOCl±10% ERY groups and between the 5.25% NaOCl±10% ERY groups (all P<0.05). The incidence of type "Adhesive" of failure modes in the 5.25% NaOCl group was significantly higher than that in other groups (all P<0.05), while the incidence of type "Adhesive" in the 5.25% NaOCl+10% ERY group was lower than that in the 5.25% NaOCl group (P<0.05).@*CONCLUSIONS@#The bonding strength to dentine increases with the increase of NaOCl concentration when the concentration lower than 2.5%; whereas it is decreased at a higher concentration (such as 5.25%). 10% ERY has a definite recovery effect on attenuated bonding strength to 5.25% NaOCl-treated dentine.
Subject(s)Adolescent , Adult , Ascorbic Acid , Dental Bonding , Dentin , Dentin-Bonding Agents/pharmacology , Diamond/pharmacology , Humans , Materials Testing , Microscopy, Electron, Scanning , Resin Cements/pharmacology , Sodium Hypochlorite/pharmacology , Tensile Strength , Water/pharmacology , Young Adult
OBJECTIVE@#To investigate the effect of a noval radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet on crosslinking of dentin collagen.@*METHODS@#(1) Twenty intact third molars were collected. The middle dentin discs were prepared for each tooth by low-speed water-cooled Isomet saw, and then immersed in 10% (mass fraction) H3PO4 solution for 16 h to obtain fully demine-ralized dentin collagen. The twenty dentin discs were then randomly divided into five groups. The control group was untreated while the four experimental groups were treated by plasma jet with gas temperature of 4 ℃ for different times (20 s, 30 s, 40 s, and 50 s). The structure and crosslinking degree of dentin collagen were characterized by attenuated total reflection-Fourier transform infrared spectroscopy. The surface morphology of demineralized dentin was observed by scanning electron microscope, and the microstructure was observed by transmission electron microscope. (2) Fourty non-caries third molars were collected to prepare 5 g fine dentin powder, then completely demineralized with 10% H3PO4 solution. The control group was untreated, while the four experimental groups were treated by plasma jet for 20 s, 30 s, 40 s and 50 s. The crosslinking degree of each group was determined by ninhydrin colorimetric method. (3) Forty intact third molars were collected to obtain dentin strips. Only two central symmetrical dentin strips (nasty 80) were taken from each tooth and immersed in 10% H3PO4 solution for 16 h to obtain fully demineralized dentin collagen. Eighty dentine collagen fiber strips were randomly divided into five groups. The control group was untreated and the axial surfaces of dentin collagen fiber strips in the expe-rimental groups were treated with the plasma jet for 20 s, 30 s, 40 s and 50 s. The ultimate tensile strength of dentin was measured by universal mechanical machine.@*RESULTS@#(1) The surface morphology of demineralized dentin observed by scanning electron microscope showed that the network structure of collagen fibers on the surface of demineralized dentin treated with the plasma jet for 20 s, 30 s and 40 s could maintain the uncollapsed three-dimensional structure, and part of the microstructure was destroyed after plasma jet treated for 50 s. After being treated by plasma jet for 20 s, 30 s and 40 s, the three-dimensional structure was uncollapsed, and the typical periodic transverse pattern of natural type Ⅰ collagen fiber could be seen. The results of infrared spectra showed that the secondary conformation of dentin collagen fibers was the same as that of the control group after being treated with the plasma jet, and the intensity of amide band was significantly increased after being treated for 30 s and 40 s. (2) The results of ninhydrin crosslinking test showed that the crosslinking ratio of dentin collagen treated by plasma jet for 30 s and 40 s was the highest, and the difference was statistically significant (P < 0.05). (3) The results of dentin ultimate tensile strength showed that the control group was (1.67±0.24) MPa, and the plasma jet treated 20 s, 30 s, 40 s and 50 s groups were (4.21±0.15) MPa, (7.06±0.30) MPa, (7.32±0.27) MPa, and (6.87±0.17) MPa, which were significantly different from that of the control group (P < 0.05).@*CONCLUSION@#The novel RF-APGD plasma jet treatment can promote the crosslinking degree of demineralized dentin collagen and improve their ultimate tensile strength.
Subject(s)Collagen , Dental Bonding , Dentin , Dentin-Bonding Agents , Microscopy, Electron, Scanning , Tensile Strength
Objective: To study the effect of hydroxyapatite (HA) based agents on the bonding properties of universal adhesive with different application modes, and to provide evidence for the use of adhesives after desensitization treatment. Methods: Sixty impacted third molars were extracted and selected (acquired from Department of Oral and Maxillofacial Surgery, College of Stomatology, Xi'an Jiaotong University). Four third molars were used to prepare 1 mm thick dentin disks and treated with 1% citric acid to simulate sensitive tooth models. The dentin surfaces were observed by scanning electron microscope (SEM) after treating with no desensitization (control group), desensitized by HA based toothpaste Biorepair and Dontodent Sensitive respectively (desensitizing toothpaste A group and B group), or HA paste treatment (desensitizing paste group ) (n=2 per group). The remaining teeth were selected to expose the mid-coronal dentin and establish dentin sensitivity models. Then, the specimens were divided into 4 former groups and received corresponding treatment. Each group was randomly divided into 2 subgroups, and intermediately strong universal adhesive (G-Premio Bond) was applied on the desensitized dentin by either etch-and-rinse mode or self-etch mode. Resin-dentin slice specimens (n=4 per subgroup), microtensile specimens (n=20 per subgroup) and slice specimens (n=6 per subgroup) were prepared. The microstructure and nanoleakage of the adhesive interfaces were observed by scanning electron microscopy (SEM). The microtensile strength (bond strength) and fracture mode were tested and recorded. The water permeability of the adhesive interface was observed by laser scanning confocal microscopy (LSCM). Results: SEM showed that desensitizing toothpaste and desensitizing paste could partially or entirely occlude most of the dentin tubules. For the etch-and-rinse mode, the bond strength of specimens treated with toothpaste A [(40.98±4.60) MPa], toothpaste B [(40.89±4.64) MPa] and HA paste [(41.48±3.65) MPa] was significantly higher than that of the control group [(38.58±4.28) MPa] (F=3.89,P<0.05). There was no statistically significant difference in bond strength among the 4 subgroups for self-etch modes (F=0.48,P>0.05). After desensitization, the bond strength of the control group and desensitizing groups in the self-etch mode was significantly higher than that in the etch-and-rinse mode (P<0.05). The overall fracture modes were mixed failure and interfacial failure in the control group and desensitizing groups. SEM showed speckled silver-stained particles deposited along the bottom of the hybrid layer on the bond interface of etch-and-rinse mode, and there were few silver-stained particles deposited on the bond interface of self-etch mode. LSCM showed continuous linear penetration in the hybrid layer of etch-and-rinse mode subgroups and discontinuous linear penetration in the hybrid layer of self-etch mode subgroups. Conclusions: HA based desensitizers have no adverse effect on the bond strength of intermediately strong universal adhesive and show good bonding performance accompanied with the self-etch mode.
Subject(s)Adhesives , Dental Bonding , Dental Cements , Dentin , Dentin-Bonding Agents , Durapatite , Humans , Materials Testing , Microscopy, Electron, Scanning , Resin Cements , Tensile Strength
Aim: The aim of this study was to compare the microtensile bond strength (µTBS) and the characteristics of the adhesive interface of Scotchbond Universal - SU etch-and-rise mode (3M ESPE) and Adper Scotchbond Multi-Purpose - MP (3M ESPE) to dentin over time. Methods: Class I cavity preparations were performed in 60 human molars that were randomly divided according to the dentin bonding system (DBS) used (n=30): (1) Acid conditioning + SU and (2) Acid conditioning + MP. For bonding strength (BS) analysis, 30 teeth (n = 15) were sectioned into sticks and submitted to the microtensile test in a universal testing machine after 24 hours and 12 months. The adhesive interface of the others 30 teeth was analyzed in a confocal microscope after 24 hours and 12 months. The data of µTBS were analyzed by two-way repeated measures ANOVA and Tukey's HSD (α = 0.05). Results: SU presented the lowest DBS compared to MP (p=0.000). Time did not influenced DBS for both adhesive systems (p=0.177). Confocal microscopy analysis showed no cracks between both adhesive systems tested. Conclusion: The results indicate that MP - µTBS showed a better performance compared to SU in total-etch mode
Subject(s)Humans , Dentin-Bonding Agents , Microscopy, Confocal , Dentin , Methacrylates
Aim: Recent reports indicate that deproteinization of acid-etched dentin surface can extend penetration depth of adhesive agents. The main goal of the present research was to investigate the deproteinization effect of Nd:YAG and diode 940 lasers on acid-etched dentin and microleakage grade in class V composite restorations. Methods: 36 extracted human premolar teeth were selected to make standard buccal and lingual class V cavities. These samples were randomly split into three sub-groups: 1.Control group, in which composite was applied for restoration after etch and bonding process without deproteinization; 2.Nd:YAG laser group, in which the teeth were deproteinized with Nd:YAG laser after etching and painting internal surfaces of cavities with Van Geison stain and then composite restorations applied just as control group; 3.Diode laser group, in which the process was similar to Nd:YAG laser group, but instead, diode 940 laser was irradiated. The teeth were bisected into two equal longitudinal buccal and lingual halves. Marginal microleakage of samples was scored by using a stereomicroscope. Kruskal- Wallis, Mann-Whitney U and Fisher's statistical tests were employed for analysis of the obtained data. Results: A significant reduction in marginal microleakage was observed for both groups treated with laser (Nd:YAG and diode 940)compared to control (p=0.001 & p=0.047). There was no significant difference in marginal microleakage between Nd:YAG laser and diode 940groups (P = 0.333). Conclusion: Nd:YAG and diode 940 laser deproteinization of acid-etched dentin decreased the marginal microleakage of in-vitro class V resin composite restorations