Effect of incorporation of silane in the bonding agent on the repair potential of machinable esthetic blocks

Abstract

Objective:To investigate the repair potential of CAD/CAM (computer-aided design/computer-aided manufacturing) ceramic and composite blocks using a silane-containing bonding agent with different repair protocols.Materials and Methods:Twenty-four discs were constructed from CAD/CAM ceramic and composite blocks. The discs were divided into six groups according to surface pre-treatment employed; GI: Diamond stone roughening (SR), GII: SR+ silanization (SR+S), GIII: Hydrofluoric acid etching (HF), GIV: HF+ silanization (HF+S), GV: Silica coating (SC), GVI: SC+ silanization (SC+S). Silane-containing bonding agent (Single Bond Universal adhesive, 3M ESPE) was applied to the pre-treated discs. Prior to light curing, irises were cut from tygon tubes (internal diameter = 0.8 mm and height = 0.5 mm) and mounted on each treated surface. Nanofilled resin composite (Filtek Z350XT, 3M ESPE) was packed into the cylinder lumen and light-cured (n = 10). The specimens were subjected to microshear bond strength testing (μ-SBS) using universal testing machine. Failure modes of the fractured specimens were analyzed using field emission scanning electron microscope (FESEM). Eight representative discs were prepared to analyze the effect of surface treatments on surface topography using FESEM. μ-SBS results were analyzed using ANOVA and Tukeys post-hoc test.Results:Three-way ANOVA results showed that the materials, surface pre-treatment protocols, and silanization step had a statistically significant effect on the mean μ-SBS values at P ≤ 0.001. For ceramic discs, the groups were ranked; GIV (24.45 ± 7.35)> GVI ((20.18 ± 2.84)> GV (7.14 ± 14)= GII (6.72 ± 1.91)=GI (6.34 ± 2.21)=GIII (5.72 ± 2.18). For composite discs, groups were ranked; GI (24.98 ± 7.69)=GVI (24.84 ± 7.00) >GII (15.85 ± 5.29) =GV (14.65 ± 4.5)= GIV (14.24 ± 2.95)≥ GIII ((9.37 ± 2.78).Conclusion:The additional silanization step cannot be omitted if the repair protocol comprises of either hydrofluoric acid etching or silica coating for both CAD/CAM esthetic restorative materials. However, this step can be suppressed by using silane-containing adhesive with diamond stone roughened repair protocol.

Bonding of the silane containing multi-mode universal adhesive for lithium disilicate ceramics

“…Another explanation is that the concentration of silane in MUA might not be sufficient to react with the hydroxyl groups of the ceramic surface. This was confirmed by the studies by Zaghloul et al35 and Kalavacharla et al26 According to these authors, treatment with silane followed by MUA significantly improved the bond strength between the ceramic and the composite resin. The additional silanization step enhanced chemical bonding to the exposed hydroxyl groups and surface wettability with resin impregnation.…”

“…Because the pH of MUAs is 2.2 to 3.2 for self-etching capability, a self-condensation reaction occurs in the silanol groups of hydrolyzed silane 3334. A second possible explanation is that Bis-GMA in MUAs significantly inhibits the condensation reaction between the hydroxyl groups of lithium disilicate ceramic and the silanol groups of silane 35. Moreover, extra resin could inhibit the condensation reaction that releases water molecules according to the Le Chatelier principle 36.…”

Bond strength between composite repair and polymer‐infiltrated ceramic‐network material: Effect of different surface treatments

“…The BisGMA component can prevent the reaction between the silane and the hydroxyl group of the ceramic surface containing silica . A balance between the hydroxyl groups of the inorganic substrate and the hydrolysable functional groups in the silane is required to improve the bond strength . The results of the present study suggest that the silane rate in the universal adhesive (approximately 10% of the volume) is not sufficient to provide similar bond strength to the use of the silane separately, probably due to the incompatibility with the amount of hydroxyl groups in the inorganic phase of PICN.…”

“…The present study found the highest bond strength values for the groups treated with the silane, alone or combined to the silane‐containing adhesive, compared to the single use of silane‐containing adhesive (universal), accepting the first hypothesis. Universal adhesives were introduced to simplify the bonding protocol and, consequently, reduce the clinical time . Besides the silane already mentioned, the universal adhesive tested contains several components according to the manufacturer: MDP, BisGMA, Vitrebond Copolymer, HEMA, filler, ethanol water, and initiators.…”

Influence of different surface treatments of fiberglass posts on the bond strength to dentin

“…In addition, after heat-treating the silane, higher bond strength values may be achieved due to the removal of the upper layers of silane, leaving a more stable silane layer at the bonding interface 37 . Failure mode analysis showed that, in the three groups, mixed failure was predominant, indicating that there was a good interaction of the resin cement with the post and root dentin after the different surface treatments; thus, the adhesion process was effective 31,[39][40][41][42] . Previous studies have reported that clinically…”