Effect of universal adhesives on microtensile bond strength to hybrid ceramic

Abstract

Background The aim of this study was to evaluate the effect of universal adhesives (UA) and silane on the microtensile bond strength (μTBS) of resin cement to a hybrid ceramic Vita Enamic (VE). Methods VE specimens were acid etched using hydrofluoric acid (HF) and were assigned to three groups ( n = 10) based on the applied bonding technique. In group 1 (S), a silane-based primer was used as a surface treatment prior to the application of a resin cement (Variolink Esthetic DC). In group 2, a silane-containing UA, Clearfil Universal Bond (CUB) was used for the surface treatment, and in group 3, A silane-free UA, Tetric N-Bond Universal (TNU) was used for surface treatment. Resin cement build-ups were prepared. The bonded specimens were sectioned into resin-ceramic beams. Half of the beams of each group were stored for 24 h at 37 °C and the other half were subjected to a thermo-cycling aging. The microtensile bond strength (μTBS) was measured at a crosshead speed of 0.5 mm/min. Failure modes were assessed accordingly. Data were analyzed using a) two-way analysis of variance ANOVA followed by one-way ANOVA and Tukey tests between groups and b) independent t- test to detect differences (α = 0.05) for each group. The surface topographies of the ceramic surface were evaluated using scanning electron microscopy. Results The results showed that silane-based primer (S) application resulted in significantly higher (p < 0.05) μTBS values after 24 h and after thermocycling compared to both silane-containing UA (CUB) and silane-free UA (TNU). The μTBS values of all groups were significantly reduced after thermocycling. No statistically significant difference was observed between the μTBS of CUB and TNU after 24 h. However, TNU showed significantly higher μTBS after thermocycling. Different failure modes were observed, and adhesive failure was the most common in all groups. Marked surface topographic changes were observed following HF etching. Conclusion It is concluded that, the UAs tested cannot be recommended as substitutes to the silanization of Hybrid ceramic.

Effect of different preparation designs and all ceramic materials on fracture strength of molar endocrowns

“…31 Earlier researchers have reported that the thermocycling decreased bond strength of PIC to the resin luting agent. 32 The reduced failure load in the radicular extension group could be due to the combined effect of increased stress concentration and reduced bond strength. Hence most failures in this group were favorable with the debonding of endocrowns.…”

Bonding performance of dispersed filler resin composite CAD/CAM blocks with different surface treatment protocols

“…Silane application has been recommended as a chemical pretreatment for DF-RCBs 23,35) as well as for PICN-RCBs 11,29,30,41) . Trialkoxysilanes are bi-functional molecules whose alkoxy groups have the ability to condensate with hydroxyl (-OH) groups on the substrate surface while their carbon double bonds can polymerize with the resin monomers by photo-initiated free radical polymerization 42,43) .…”

Surface treatment and adhesion approaches on polymer-infiltrated ceramic network

“…In evaluating the bond strength of PICN with two types of resin cement after several acid etching protocols combined with silane, Single Bond Universal and an association of both primers, Rohr et al 22 (2017) found that the highest bond strengths values were achieved when silane was applied followed by the universal adhesive after 5% hydrofluoric acid conditioning for 30 to 60 s. Corroborating the findings of the present study, the authors also did not find adequate mean bond strength values when universal adhesive was applied solely after HF 22 . Furthermore, Awad et al 19 (2019) also found a significantly higher performance of silane group and low bond strengths of universal adhesives after aging in comparing the behavior of a silane primer, a silane-containing universal adhesive and a silane-free universal adhesive after HF etching (4.6%) on μTBS of PICN with resin cement. These results seem to demonstrate that chemical adhesion promoted by UA and PICN was not sufficient compared to silane (HF-S).…”

“…Furthermore, adhesive bonding is related to a higher fracture strength of indirect restorations and restored teeth 4,9,10 . Methods which increase the surface properties would be clinically advantageous in order to improve the adhesive bond to ceramic surfaces 7,[11][12][13] , promoting micromechanical interlocking [14][15][16] and/or surface reactivity for chemical bonding [17][18][19] .…”

“…Silane coupling agent has demonstrated a positive impact on the bond strength of composite cements to PICN 4,19,26,27 . However, only the ceramic component of PICN has a chemical bond to silane, as the resinous component presents limited reactive groups available for bonding after polymerization 22 .…”