Effect of anti-COVID-19 mouthwashes on shear bond strength of resin-matrix ceramics repaired with resin composite using universal adhesive

Using anti-COVID-19mouthwashes has become necessary to reduce Acute Respiratory Syndrome Coronavirus 2 ( SARS- CoV- 2) transmission. Resin- Matrix Ceramic (RMC) materials exposed to mouthwashes may affect the bonding of the repaired material. This research was investigated to assess the effect of the antiCOVID- 19 mouthwash on shear bond strengths (SBS) in RMC repaired with resin composite. The 189 rectangular specimens per material of the two different RMCs (Vita Enamic (VE) and Shofu Block HC (ShB)) were thermocycling and randomly divided into 9 subgroups according to mouthwash types of ( distilled water ( DW) , 0. 2%povidone-iodine (PVP-I) and 1.5% Hydrogen peroxide (HP)) and surface treatments protocol ( no surface treatment, hydrofluoric acid etching (HF) and sandblast (SB)). The repair protocol for RMC was performed ( using universal adhesive and resin composite) and specimens were assessed by SBS test. The failure mode was examined using the stereomicroscope. SBS data were evaluated by 3-way ANOVA and Turkey post hoc test. The SBS were significantly affected by RMC, mouthwash and surfacetreatment protocol. Both of the surface treatment protocols (HF and SB) to both RMC improved the SBS whether immersed in anti-COVID-19 mouthwash or not. For VE immersed in HP and PVP- I, HF surface treatment had the highest SBS. For ShB immersed in HP and PVP-I, SB surface treatment had the highest SBS.