Shear vs. Tensile Bond Strength of Resin Composite Bonded to Ceramic

Abstract Background The resin bond strength of sclerotic dentine is significantly lower than that of the normal dentine, which paused a challenge for bonding procedures clinically. The aim of this study was to compare the effects of different surface pretreatments on the micro-tensile bond strength and microstructure between sclerotic dentine and normal dentine. Methods Eighty teeth that were collected, forty premolars with typical wedge-shaped defects visually graded as class III were assigned as the sclerotic dentine group (SD), the other forty normal premolars with artificial wedge-shaped defects were assigned as the normal dentine group (ND). Each group was randomly subdivided into eight subgroups according to the solution used: 35% phosphoric acid, 15% EDTA, 5% or 10% NaClO. Then the dentine surface was examined using a scanning electron microscope (SEM). The lesions were restored using self-etching adhesive and the subsequent resin composite. The teeth were sectioned into sticks for the micro-tensile bond strength analysis, and the data were analysed using the SPSS17.0 software package (α = 0.05). Results First, for the ND groups, after pretreatment using 35% phosphoric acid, and 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the normal dentine were higher than that of the other groups (P < 0.05). Second, for the SD groups, after pretreatment using 35% phosphoric acid, 15% EDTA, and 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the sclerotic dentine were higher than that of the other groups (P < 0.05). Third, the bond strengths of the sclerotic dentine were lower than that of the normal dentine without any pretreatment (P < 0.05). After pretreatment using 35% phosphoric acid + 5% or 10% sodium hypochlorite, the bonding strengths of the sclerotic dentine were higher than that of the normal dentine (P < 0.05). SEM observation showed that the appearances of dentine surface were changed after pretreatment using the above solutions, with the reduced smear layer, opened small groove and increased dentinal tubules. Conclusion Pretreatment of dentine using 35% phosphoric acid+ 5% or + 10% sodium hypochlorite changed the microstructure of the sclerotic dentine surface and subsequently increased the micro-tensile bond strength.

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The finish line location of the cemented crown is an influencing factor for tensile bond strength, marginal adaption and nanoleakage?

Brazilian Dental Science ◽

10.14295/bds.2020.v23i2.1924 ◽

2020 ◽

Vol 23 (2) ◽

Author(s):

Enrico Angelo ◽

Rodrigo Esteves Barros Lins ◽

Luis Roberto Marcondes Martins

Keyword(s):

Bond Strength ◽

Epoxy Resin ◽

Resin Composite ◽

Influencing Factor ◽

Resin Cement ◽

Tensile Bond Strength ◽

Adhesive Failure ◽

Finish Line ◽

Significance Level ◽

Spearman Correlation Test

Objective: The aim of this study was to evaluate the influence of different crowns finishing line location on the crown tensile bond strength, marginal adaption and nanoleakage. Material and Methods: Sixty healthy third molars were collected. For tensile bond strength, a self-adhesive resin cement was used. For marginal adaption, epoxy resin models were prepared. Prior to tensile bond strength test, images for the epoxy resin models were measured under scanning electron microscopy (SEM). Nanoleakage was measured using same protocol. Failure mode was evaluated through SEM and classified: adhesive failure, cohesive in cement, cohesive in dentin, cohesive in resin composite, cohesive in enamel, and mixed. Statistical analysis was performed using Shapiro-Wilk and Kolmogorov Smirnov normality tests, two-way ANOVA, Bonferroni (posthoc) parametric test, with significance level of 5% (P < .05), Spearman correlation test. Results: tensile bond strength was not statistically different between the cemented groups with composite resin and ceramic. Cementation of ceramic was not statistically different between the groups (enamel, 3.28 Pa; dentin, 3.14 Pa; resin, 2.85 Pa). Marginal adaption was statistically different between resin and ceramic; finish line location varied between enamel and resin (175.91 μm vs. 433.58 μm). Nanoleakage rate was statistically different among all groups, except for resin: with resin (9.49%) and ceramic (9.35%). There was a predominance of adhesive failure in all groups. Conclusion: finish line location can be performed safely in enamel and dentin. Composite resinas substrate present an alternative, but still need to be more studied. Regarding the crown’s material, it is possible to perform a satisfatory restoration in both: resin and ceramic. With ceramics presenting better results. KEYWORDSResin composite; Ceramics; Tensile bond strengh; Marginal adaption; Nanoleakage.

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Effect of tooth age on bond strength to dentin

Journal of Applied Oral Science ◽

10.1590/s1678-77572003000400013 ◽

2003 ◽

Vol 11 (4) ◽

pp. 342-347 ◽

Cited By ~ 5

Author(s):

Marcelo Giannini ◽

Patrícia Chaves ◽

Marcelo Tavares de Oliveira

Keyword(s):

Bond Strength ◽

Resin Composite ◽

Testing Machine ◽

Age Groups ◽

In Vitro Study ◽

Adhesive System ◽

Tensile Bond Strength ◽

Significant Difference ◽

Diamond Saw

This in vitro study evaluated the effect of tooth age on the tensile bond strength of Prime & Bond NT adhesive system to dentin. Human third molars from the five age groups were analyzed: A- 17 to 20yrs, B- 21 to 30yrs, C- 31 to 40yrs, D- 41 to 50yrs and E- 51 to 63yrs. The occlusal enamel was removed using a diamond saw under water cooling and the dentin surface was wet-ground with 600-grit SiC paper to obtain flat surfaces. The adhesive system was applied according to the manufacturer's instructions and a 6-mm high resin "crown" was built-up with resin composite. Teeth were stored for 24 hours in distilled water at 37ºC and prepared for micro-tensile testing. Each specimen was mounted in a testing jig attached to a universal testing machine and stressed in tension at a crosshead speed of 0.5mm/min until failure. The means of tensile bond strength were (MPa): A- 21.42 ± 7.52ª; B- 30.13 ± 10.19ª; C- 31.69 ± 11.78ª; D- 30.69 ± 8.47ª and E- 35.66 ± 9.54ª. No statistically significant difference was observed among the age groups (p > 0.05). The results suggested that the tensile bond strength of the adhesive system was not significantly affected by dentin aging.

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