The effect of surface treatment with a fractional carbon dioxide laser on shear bond strength of resin cement to a lithium disilicate‐based ceramic

This study investigated the impact of different surface treatments, including fractionalcarbon dioxide (CO2) laser on shear bond strength (SBS) of resin cement to lithium disilicate ceramic.
In this in vitro study, 72 blocks of IPS e.max CAD ceramic were randomlydivided into six groups in terms of treatment (n = 12). Group 1 underwent etching with 9.6%hydrofluoric (HF) acid, whereas group 2 was subjected to air abrasion with aluminum oxide particles.Groups 3 and 4 were treated with a fractional CO2 laser for 10 s using 10 W/14 mJ (group 3) or20 W/10 mJ (group 4). In groups 5 and 6, the CO2 laser was applied similar to that in groups 3 and4, respectively; then, the specimens were etched by HF acid. After silane application, luting cementwas bonded to the specimens. The SBS was assessed with a universal testing machine, and the typeof bond failure was determined. Data were analyzed by ANOVA, Duncan, and Fisher’s exact tests.
Surface conditioning with fractional CO2 laser alone resulted in significantly lower SBSthan HF acid treatment (P The combination of fractional CO2 laser irradiation and HF acid etching could berecommended when extra retention is required for lithium disilicate‑based restorations, whereaslaser treatment alone cannot produce sufficient SBS.