Microshear bond strength evaluation of surface pretreated zirconia ceramics bonded to dentin

Abstract

Objectives:To comparatively assess the micro shear bond strength (MSBS) of dentin bonded surface pre-treated zirconia ceramics.Materials and Methods:Zirconia blocks were sectioned into 50 cubical blocks. The blocks were further categorized into five groups (n = 10 each). Group I: No treatment was performed on zirconia samples; Group II: The zirconia samples were sand-blasted; Group III: Group II + etched with 9.8% of hydrofluoric (HF) acid for 60 s; Group IV: The sandblasted zirconia samples were selectively infiltrated with low fusing porcelain; and Group V: Group IV + etched using 9.8% HF acid gel. The zirconia specimens were then bonded to dentin samples, and the samples were tested for MSBS evaluation using universal testing machine.Results:The MSBS of all the four experimental groups shows greater value than group I. Among the experimental groups, group V and group IV do not show any statistical significant difference, whereas the mean MSBS of groups IV and V were statistically greater than group III and group II. However, groups I, II, and III do not show any statistical significant difference in mean MSBS values between them.Conclusion:Selective infiltration etching of zirconia ceramics provides the highest bond strength with resin cement.

Effect of selective infiltration etching on the bond strength between zirconia and resin luting agents

“…SIE starts with the application of a heated glass infiltration agent to the zirconia surface, which gives it in an eroded and porous characteristic . By means of thermal cycling, the surface is then transformed into a highly retentive, highly reactive nanoporous surface .…”

“…A hindrance to SIE's widespread adoption is that it requires more time, effort and sensitive handling during every step of the technique . Previous studies have reported that the SIE method leads to higher bond strength to zirconia than sandblasting . These findings are probably related to the differences in topography achieved by means of each technique.…”

“…15 SIE starts with the application of a heated glass infiltration agent to the zirconia surface, which gives it in an eroded and porous characteristic. 13,14 By means of thermal cycling, the surface is then transformed into a highly retentive, highly reactive nanoporous surface. 10,17,24 This method seems promising, as one study has reported that the bonding of selective-infiltration-etched partial retained zirconia restorations was strong enough to resist functional loads in the molar region.…”

“…This method provides an abraded and porous zirconia surface . Increased surface roughness and promising results have been observed in vitro, in bond strength studies …”

“…12 Increased surface roughness 13 and promising results have been observed in vitro, in bond strength studies. 11,12,14,15 The technique relies on a heat-induced maturation (HIM) process that acts by stressing zirconia grain boundaries by two short thermal cycles. In combination, a thin layer of a low melting glass with various additives that control its viscosity and thermal coefficient expansion is applied to the surface.…”