Amal Abdallah A. Abo-Elmagd^{1, 2,}, Ebtehal Mohammed³

Background: This in vitro study was conducted to investigate the effect of ultrasonic scaling on debonding of lithium disilicate glass ceramic laminate veneers restorations cemented to tooth structure. Materials and Methods: 16 extracted sound upper anterior teeth were prepared to receive laminate veneer restorations. They were randomly assigned into 2 groups (n=8), as in group Non-US , the cemented fabricated laminate veneers were not exposed to ultrasonic scaling and in the ultrasonic group (US) the cemented fabricated laminate veneers were exposed to ultrasonic scaling. The GC Initial LiSi Press Lithium disilicate glass ceramics laminate veneers were fabricated according to manufacturer instructions. The debonding force test was applied after cementation and after ultrasonic scaling using Instrone testing machine. The obtained data were tabulated and analyzed statistically. Differences were considered significant at P<0.05. Results: the recorded values of the debonding force mean ±SD for Non-US group were (79.5288 ±16.5228N) and mean ±SD values recorded for US group were (54.0713 ±8.2647 N). The T test showed significant difference between 2 groups (p value=0.0016) and 95% CI (29.45±14.0057). Conclusion(s): Within the limitations of this study, it was found that ultrasonic scaling significantly affect the debonding force of cemented laminate veneers.

debonding force, laminate veneers, lithium disilicate ceramics, press ceramic ultrasonic scalar