Micromorfología superficial de 2 cerámicas grabables tratadas con diferentes ácidos / Superficial micromorphology of 2 etchable ceramics treated with different acids

Para lograr una unión fuerte entre las restauraciones de cerámica sin metal y las resinas de cementación se indican acondicionamientos de superficie previos a la cementación. Nuestro objetivo es describir y comparar al MEB las superficies de cerámicas feldespáticas y reforzadas con disilicato de litio antes y después de ser tratadas con 2 procedimientos ácidos. Se utilizaron 8 bloques de cerámica feldespática (A) y 8 de cerámica reforzada con disilicato de litio (B). Se subdividieron en 2 grupos de 4 bloques (A1 y A2) y (B1 y B2). Los grupos A1 y B1 fueron tratados con ácido fluorhídrico 9% (HF) y los grupos A2 y B2 con ácido fluorhídrico, seguido de ácido fosfórico al 35%. Posteriormente, se observaron al MEB (1.000 ×) y se procesaron las imágenes con el programa Matlab R2012a, que mide el contraste. Los estadísticos utilizados fueron el test ANOVA y el test «t¼ no pareado Resultados El ácido fluorhídrico 9% crea irregularidades en ambos tipos de cerámicas. Al aplicar HF, seguido de ácido fosfórico sobre la cerámica feldespática no se aprecian diferencias en el contraste, con respecto a utilizar solo HF. Al usar ambos ácidos, en la cerámica reforzada con disilicato de litio se aprecian menos irregularidades respecto a las tratadas con un solo ácido. Conclusiones El ácido fluorhídrico 9% crea microrretenciones en ambas cerámicas. El HF al 9%, seguido del ácido fosfórico 35% parece modificar los valores de contraste de la cerámica colada, en cambio en las feldespáticas no hay diferencias significativas con ambos tratamientos.

Surface conditioning prior to cementing is indicated to achieve a strong bond between metal-free ceramic restorations and resin cements. The aim of this study is to describe and compare the scanning electron microscopy (SEM) images of the surfaces of Feldspathic ceramic and Lithium disilicate glass ceramic before and after being treated with two acid procedures. For this, 8 blocks of Feldspathic ceramic (A) and 8 of Ceramic lithium disilicate (B) were used. They were subdivided into two groups of 4 blocks (A1 and A2) and (B1 and B2). Groups A1 and B1 were treated with 9% Hydrofluoric Acid (HF) and the A2 and B2 groups, with 9% Hydrofluoric Acid followed by 35% Phosphoric Acid. Subsequently, they were observed using SEM (1,000 ×) and the images processed with the program Matlab R2012a, which measures the contrast. The statistics used were ANOVA test and the unpaired t test. Results 9% Hydrofluoric Acid creates irregularities in both types of ceramics. When applying HF followed by Phosphoric Acid on Feldspathic ceramics, no differences in contrast were found, compared to using only HF. With ceramic lithium disilicate using both acids, there are fewer irregularities with respect to those treated with a single acid. Conclusion 9% Hydrofluoric Acid creates micro-retentions in both ceramics. 9% HF followed by 35% Phosphoric Acid appears to significantly modify the Lithium disilicate glass ceramic contrast values. On the other hand, the Feldspathic ceramic showed no significant differences with both treatments.

Evaluation of shear bond strength of three different types of artificial teeth to heat cure denture base resin: An in vitro study.

Context: Bonding of artificial teeth and denture base material remained a significant problem for successful prosthetic treatment. Aim: The purpose of this in vitro study was to evaluate shear bond strength of three different artificial teeth with heat cure denture base material after various surface conditioning methods and thermocycling. Materials and Methods: Ninety mandibular first molar denture teeth were selected. They were divided into three groups, Group I: Nanocomposite resin (Veracia), Group II: Composite teeth (Endura), and Group III: Cross-linked acrylic denture teeth (Acry rock). All groups were further subdivided into subgroups based on surface conditioning methods. Subgroup A: No surface conditioning (control group), Subgroup B: Surface conditioning with methyl methacrylate-based bonding agent (Vitacoll), and Subgroup C: Air abrasion with 50 μm aluminum oxide powder particles plus silane-coupling agent (Monobond-S) and Vitacoll bonding agent. Evaluation of shear bond strength of all the specimens was done using universal testing machine. Results: Mean shear bond strength of Group I, Subgroup B (6.87 ± 0.934) showed higher value when compared with Group II, Subgroup B (6.76 ± 1.84) and Group III, Subgroup B (5.66 ± 2.18). The control group (untreated surface) of all three types of artificial teeth used in this study showed significantly lower shear bond strength values than experimental groups (surface conditioning methods; P < 0.05). Conclusion: The results of this study suggest that there were significant differences in shear bond strength among control group and surface treatment groups of denture teeth bonded to heat cure denture base resin.

Influencia del tiempo de tratamiento de superficie con ácido fluorhídrico de la porcelana VITA VM 13 en la resistencia de unión a cemento de resina frente a fuerzas de tracción: estudio in vitro / Influence of surface treatment time with hydrofluoric acid of VITA VM13 porcelain on tensile bond strength to a luting resin cement. In vitro study

Introducción: Los procedimientos restauradores indirectos son comunes en la clínica diaria actual. Se debe tener cuidado especial en la cementación, pues la gran mayoría de los fracasos ocurren en la interfase diente/restauración. Por esto es indispensable un adecuado tratamiento de superficie de la restauración para lograr una adhesión óptima a la superficie dentaria. Materiales y Métodos: Treinta cilindros de porcelana VITA VM 13 con dimensiones de 5 mm de altura y 7 mm de diámetro fueron separadas aleatoriamente en 3 grupos (n=10) de acuerdo con los tratamientos recibidos. Grupo I (control) - sin acondicionamiento superficial; Grupo II - grabado con ácido fluorhídrico al 9.6 por ciento por 1 minuto; Grupo III - grabado con ácido fluorhídrico al 9.6 por ciento por 2 minutos. Estas fueron probadas en cuanto a su resistencia de unión a la tracción en una máquina universal para pruebas (INSTRON modelo 4411, 3M). Los valores, expresados en MPa, fueron analizados estadísticamente a un nivel de significación del 5 por ciento, usando el Análisis de la Varianza (ANOVA) de un factor. Resultados: En relación con la prueba de resistencia de unión a la tracción, se encontraron los siguientes valores medios para cada grupo: Grupo I (control) - x=3.35 MPa; Grupo II - x=4.64 MPa; Grupo III - x=3.80 MPa. Conclusiones: Según los resultados obtenidos, se puede concluir que el tratamiento de superficie con ácido fluorhídrico durante 1 minuto, promueve microrretenciones que aumentan significativamente los valores de resistencia a la tracción, que puede traducirse en un beneficio clínico mayor.

Aim: Indirect restorative procedures are common in the current daily practice. Special care must be taken in the cement, as the vast majority of failures occurs at the interface tooth /restoration. Therefore a proper surface treatment of the restoration is essential to achieve optimum adhesion to the tooth surface. Materials and Methods: Thirty porcelain cylinders VITA VM 13 with dimensions of 5 mm in height and 7 mm in diameter were randomly divided into 3 groups (n=10) according to the treatments received. Group I (control) - no surface conditioning; Group II- recorded with 9.6 percent hydrofluoric acid for 1 minute; Group III - recorded with 9.6 percent hydrofluoric acid for 2 minutes. Their tensile bond strength was tested in a universal testing machine (Instron Model 4411, 3M). The values, expressed in MPa, were statistically analyzed at a level of significance of 5 percent, using Analysis of Variance (ANOVA) of a factor. Results: In relation to the bond strength test, tensile strength, revealed the following values for each group: Group I (control) - x=3.35 MPa, Group II - x=4.64 MPa, Group III - x=3.80 MPa. Conclusions: According to the results, it can be concluded that the surface treatment with hydrofluoric acid for 1 minute promotes microretentions, which significantly increase the values of bond strength, tensile strength. This can result in a higher clinical benefit.

Effect of surface treatments of fiber posts on bond strength to composite resin cores / 대한치과보존학회지

The purpose of the present study was to compare the influence of post-surface treatment with silane, hydrogen peroxide, hydrofluoric acid or sandblasting and to investigate the effect of silane in combination of the other treatments on the microtensile bond strength between fiber posts and composite resins for core build-up. Thirty-two glass-fiber posts (FRC Postec Plus, Ivoclar Vivadent, Schaan, Liechtenstein) were divided into eight groups according to the different surface pretreatments performed: silane application (S); immersion in 28% hydrogen peroxide (HP); immersion in hydrogen peroxide followed by application of silane (HP-S); immersion in 4% hydrofluoric acid gel (HF); immersion in hydrofluoric acid gel followed by application of silane (HF-S); sandblasting with aluminum oxide particles (SB); sandblasting followed by application of silane (SB-S). In control group, no surface treatment was performed. The composite resin (Tetric Flow, Ivoclar Vivadent, Schaan, Liechtenstein) was applied onto the posts to produce the composite cylinder specimen. It was sectioned into sticks to measure the microtensile bond strength. The data was analyzed with one-way ANOVA and LSD test for post hoc comparison (p < 0.05). Post pretreatment with sandblasting enhanced the interfacial strength between the fiber posts and core materials. Moreover, sand-blasting followed by application of silane appears to be the most effective method that can improve the clinical performance of glass fiber posts.

The influence of surface conditioning on the shear bond strength of self-adhesive resin cement to zirconia ceramics / 대한치과보철학회지

PURPOSE: To evaluate the effect of surface conditioning on the shear bond strength of zirconium-oxide ceramic to 4 luting agents. MATERIAL AND METHODS: A total of 120 disk-shaped zirconium-oxide ceramic blocks (3Y-TZP, Kyoritsu, Japan) were treated as follows: (1) Sandblasting with 110 microm aluminum-oxide (Al2O3) particles; (2) tribochemical silica coating (Rocatec) using 110 microm Al2O3 particles modified by silica; (3) no treatment. Then zirconium-oxide ceramic blocks bonded with 4 luting cements (RelyX luting (3M ESPE), Maxcem (Kerr), Nexus3 (Kerr), Rely X Unicem (3M ESPE)). Each group was tested in shear bond strengths by UTM. A 1-way analysis of variance and 2-way analysis of variance was used to analyze the data (alpha = .05). RESULTS: RelyX unicem in combination tribochemical silica-coating produced a highest bond strength (P < .05). Air abrasion group and Rocatec treatment groups resulted in significantly higher than no conditioning group (P < .05). RelyX Luting groups showed lower bond strength than other groups. There were significant differences among groups (P < .05). CONCLUSION: Within the limitation of this study, RelyX Unicem cement provided the highest bond strength and Rocatec treatment enhanced the bond strength.

Avaliação de três métodos de tratamento de superfície em uma resina compostas indireta / Evaluation of three methods of surface treatment in an indirect composite resin

O objetivo do estudo foi avaliar tratamentos de superfície da resina composta indireta Sinfony (3M) para o seu reparo caso haja uma fratura. Para o experimento foram realizados 6 blocos de resina composta indireta Sinfony (3M) de dimensões 6x6x12mm. Estes blocos foram divididos ao meio no seu maior comprimento e distribuídos para três grupos. No grupo 1, os espécimes foram condicionados por ácido fosfórico por 30 segundos, o grupo 2, por ácido fluorídrico por 30 segundos e no grupo 3, por jateamento de óxido de alumínio de 50µ por 5 segundos. Na superfície cortada do bloco foi realizado o tratamento de superfície e o reparo devolvendo as dimensões iniciais de cada bloco. Para todos os grupos foram utilizados sistema adesivo Adper Scothbond Multiuso (3M) e resina composta direta Filtek Z350 (3M). Os blocos foram fixados a uma máquina de corte e obtido 36 fatias de aproximadamente 1 mm² de base por 12 mm de comprimento por grupo para a realização do teste de microtração. Os resultados mostraram para cada grupo as seguintes médias e desvios-padrão em MPa não havendo diferença estatística entre eles: Grupo 1 - 33,99±19,45; Grupo 2 - 29,16±13,02; Grupo 3 - 30,13±19,75. Concluiu-se que qualquer dos três tipos de tratamento de superfície para reparo em resina composta indireta Sinfony tem resultados semelhantes quanto à resistência adesiva.

The objective of this study was to valuate surface conditionings of indirect composite resin Sinfony (3M) for his/her repair in case there is a fracture. For the study, 6 blocks of indirect composite rsin Sinfony (3M) of dimensions 6x6x12mm were made. The groups were divided in three of agreement conditioning surface. For all of the groups were used adhesive system Adper Scothbond Multi-uso (3M) and composite direct resin Filtek Z350 (3M). In the group 1, the specimens were conditioned by phosphoric acid by 30 seconds, the group 2, for fluoredric acid for 30 seconds and in the group 3, for oxide of aluminum sandblasting of 50µ for 5 seconds. Each group received two blocks. These blocks were divided to the middle in largest length, obtaining a total of four blocks for each group. In the cut surface, the repair was accomplished returning the initial dimensions of each block. Each block was adapted to a cut machine and obtained 9 slices of approximately 1mm² of base area and 12mm of length for the microtensile test. The result showed for each group the following mean and standard-deviation in Mpa, not having difference statistics among them: Grupo 1 - 33,99±19,45; Grupo 2 - 29,16±13,02; Grupo 3 - 30,13±19,75. Concluded that any of the three types of surface treatment for repair in indirect resin composite Sinfony has similar results as for the adhesive resistance.

EFFECT OF DIFFERENT SURFACE CONDITIONING METHODS ON SHEAR BONDING STRENGTH OF GLASS-INFILTRATED CERAMIC I TO DENTINE / 解放军医学杂志

To investigate the effects of different surface conditioning methods on the shear bonding strength of glass-infiltrated ceramic to dentine, 24 glass-infiltrated ceramic testing-pieces were divided into four groups randomly. Among them 3 groups were treated with A(sandblasting+silance), B(etching+silace) or C(silance), separately, while group D was set as the control. Bonding the ceramic pieces to dentine with Super-Bond and the shear bonding strengths was measured. The results showed that the shear bonding strength of group D was lower than that of group A, B and C (P0.05). It is suggested that surface conditioning using combined sandblasting with silance can remarkbly improve the shear bonding strength of glass-infiltrated ceramic to dentine.