The effect of different surface treatments and bonding agent combinations on the shear bond strength of titanium alloy to lithium disilicate glass-ceramics

Abstract

Statement of problem. The esthetic challenges of using titanium alloyabutments have led to the increasing use of prefabricated titanium insertsbonded to tooth colored abutments and fixed dental prostheses. Optimalbonding protocol related to surface treatment of titanium alloy have not beenestablished.Purpose. The purpose of this in vitro study was to assess the effects ofdifferent surface treatment and cementation procedure combinations of titaniumalloy disks on the bond strength of lithium disilicate glass-ceramics.Material and methods. A total of 40 computer-aided designed andcomputer-aided manufacturing (CAD-CAM) titanium alloy disks (4×6.6 mm)were used. Specimens were divided into two groups (2 groups; n=20/ group)according to surface treatment type including alumina airborne- particle abrasion(50µm, 0.4 Mpa for 10 seconds at 20-mm distance) and 9.5% Hydrofluoric acidetching gel for 90 seconds. Heat-pressed lithium disilicate disks were fabricatedand bonded with resin cements onto the treated surfaces after dividing eachgroup into two subgroups (2 subgruops; n=10/subgroup) depending on the typeof resin cement was used Multilink Hybrid abutment cement or Panavia SA pluscement . All the specimens were stored in the distilled water at 37℃for 24 hoursthen 5000 cycles of thermal cycling were done. After thermcycling shear bondstrength test was conducted using a universal testing machine. Statisticalanalysis were done by ANOVA and Tukey honset sinificant differences tests (P<0.05).Results. The mean of ±SD shear bond strength values ranged from3.89±0.59 MPa to15.91±3.23 MPa.The highest shear bond strength values were xiiobtained using airborne-particle abrasion. Resin cements tested in this studyhad similar effect on the bonding strength values.Conclusions. Surface treatment of titanium alloy with sandblastingimproved shear bond strength but increasing the etching time of 9.5%Hydrofluoric acid did not. The cement type didn't have a significant influence onshear bond strength.Key words: Titanium alloys, dental implant abutment, shear bond strength