Cumhuriyet Dental Journal (Feb 2021)
Influence of different repair protocols and artificial aging on bond strength of composite to a CAD/CAM polymer-infiltrated ceramic
Abstract
Abstract Objectives: The repair bond strength of the composite to a polymer-infiltrated ceramic network (PICN) restoration may vary depending on the repair protocol used and may decrease over time. The aim of this study was to evaluate the effects of different repair protocols and artificial aging on shear bond strength (SBS) of a composite for repair to PICN material. Materials and methods: Artificially aged specimens (5000 thermal cycles between 5°C and 55°C) sliced from PICN CAD/CAM blocks (Vita Enamic) were randomly divided into 5 groups according to the repair protocol applied: 1) TS: tribochemical silica coating-Single Bond Universal 2) ES: etching with hydrofluoric acid (HF)-Single Bond Universal 3) EU: etching with HF-Ultradent Porcelain Repair System 4) GU: grinding with diamond bur-Ultradent Porcelain Repair System 5) GI: grinding with diamond bur-Ivoclar Vivadent Ceramic Repair System. After receiving a composite resin cylinder for repair, specimens were further divided into 2 subgroups considering artificial aging procedure (n=12): baseline/aging (5000 thermal cycles between 5°C and 55°C). SBS tests were performed by using a universal testing machine and failure types were classified as cohesive failure in PICN, cohesive failure in composite, adhesive, and mixed. The SBS data were analyzed with 1-way ANOVA,factorial ANOVA, least signifigance difference, and Duncan tests (α=0.05). Failure modes were calculated as a percentage. Results: The mean SBSs for ES and GU were higher than TS at baseline (p<0.05). After aging procedure, EU and GU showed lower SBS than ES (p<0.05). Aging decreased the SBS for ES, EU and GU compared to baseline (p<0.05). The failure modes in general were observed as cohesive in PICN at baseline, while the only group that showed cohesive failure predominantly was EU after aging. Conclusions: Considering the time-efficiency and effectiveness, etching with HF followed by Single Bond Universal application can be recommended as the intraoral repair protocol for PICN.
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