Efficacy of two polishing systems in reestablishing the surface smoothness of posterior monolithic lithium disilicate restorations: One-year results of a split-mouth randomized controlled clinical trial

• Published in: The Journal of prosthetic dentistry 2024-01, Vol.131 (1), p.25-33
• Main Authors: Caixeta, Mariana Tassinari, de Oliveira, Danila, Isquierdo de Souza, Fernando, Rocha, Eduardo Passos
• Format: Article
• Language: English
• ISSN: 0022-3913; 1097-6841
• DOI: 10.1016/j.prosdent.2022.01.008

Selecting the optimal polishing procedure to reestablish surface smoothness after occlusal adjustment is essential for the long-term success of glass-ceramic restorations. While in vitro studies have shown different effective polishing protocols, clinical trials are lacking. The purpose of this split-mouth controlled clinical trial was to evaluate the effectiveness of 2 polishing systems in reestablishing the surface smoothness of posterior monolithic lithium disilicate ceramic restorations. Ninety-six restorations that required occlusal adjustment after bonding were randomized into 2 groups: Forty-eight restorations were polished by using the Exa Cerapol polishing kit, and the other 48 restorations were polished by using the Shofu polishing kit. The restorations were replicated with epoxy resin at 3 study times—after bonding (t1), after occlusal adjustment (t2), and after polishing (t3)—for quantitative roughness analysis (Ra). Representative specimens from each group were qualitatively analyzed by using a confocal laser microscope. Clinical analyses were performed after the polishing procedure and at 30, 180, and 365 days after the polishing procedure by following the United States Public Health Service (USPHS) criteria. ANOVA and the Tukey multiple comparisons parametric tests were computed (α=.05). The Kaplan-Meier test was used to analyze the survival rate of restorations. No statistically significant difference was found between the Exa Cerapol and Shofu groups (P=.086). A statistically significant difference was found between study times t1 and t2 and between t2 and t3 (both P