Preheated acid associated with silane and electric current in the adhesion of the resin cement to ceramic

Abstract

This study verified the effect of the combination of preheated hydrofluoric acid/silane/electric current in the adhesion of the resin cement to ceramic. IPS E.max Press ceramic discs embedded in PVC rigid tubes were divided into four groups associating preheated hydrofluoric acid and silane applied with electrical current (n=10): Ha+S (Heated acid + silane); Ha+S+Ec (Heated acid + silane + electrical current); A+S (Acid + silane) and A+S+Ec (Acid + silano + electrical current). Resin cement/ceramic samples were stored in water at 37°C for 24h. After storage, they were submitted to the microshear test, fracture analysis, and contact angle at 24h or after thermocycling (10,000 cycles/5-55ºC). Bond strength data were evaluated by two-way ANOVA. For comparison between evaluation times (24h or thermocycling) was applied unpaired t-test. A significance post-hoc test of p=0.05 was assumed for analyses and graphs (GraphPad Prism 9.0 software). At 24h, the microshear strength showed similar values between Ha+S, Ha+S+Ec, and A+S+Ec groups, while A+S showed the lowest value with a statistical difference. After thermocycling, Ha+S and Ha+S+Ec were similar, as well as A+S and A+S+Ec. There was a significant difference in all groups comparing 24h (highest value) with after thermocycling (lowest value). Adhesive fracture was predominant in all groups and evaluation times. Ha+S and A+S groups showed higher contact angle values compared to the Ha+S+Ec and A+S+Ec with lower values. In conclusion, the association of preheated hydrofluoric acid/silane applied or not with electric current promoted different microshear strength values, fracture types, and contact angles in the resin cement/ceramic bond.

Major outcomes of clinical and experimental studies to highlight the importance of using silane in composite resin restorations in modern dentistry: a systematic review

“…Adhesive fracture was predominant in all groups and evaluation moments. The Ha+S and A+S groups presented higher contact angle values compared to the Ha+S+Ec and A+S+Ec groups with lower values [7].…”

“…The composite resin to be used should be applied, choosing the appropriate material for each case [2,3]. Some work, analyzing the relevance of various chemical and mechanical treatments in old composite resins and repair bond strength, concluded that the improvement in the bond strength between the new and the old composite resin restoration requires increased harshness to institute micromechanical union between the surface of the old composite resin and the resin together [4,5].…”

“…The use of drills, followed by acid etching and application of adhesive, appears to be used by more than 80% of dentists as a pre-treatment of the old composite to be repaired. In vitro data can help elucidate whether silane treatment of composite resin surfaces before repair is indispensable [3][4][5].…”

“…However, for the conditioned groups there was no difference between the silane and the silane associated with dentin adhesive. Acid etching of porcelain significantly increased strength in all bonding methods and was the main contributor to the values obtained [2][3][4].…”