Purpose: Although there are short-term clinical reports of CAD/CAM-produced composite resin crowns using hybrid resin blocks for premolars, a long-term survey under certain conditions of intracrown pretreatment is needed because variations were seen in previous reports. The purpose of this study was to evaluate the longevity of premolar CAD/CAM-produced composite resin crowns installed under certain conditions of pretreatment.
Methods: During the 6 years from April 1, 2014 to March 31, 2020 at the Departments of Prosthodontics and Implantology, Fukuoka Dental College Medical and Dental General Hospital, we performed a retrospective study of premolar CAD/CAM-produced composite resin crowns placed by 16 dentists with at least three years of clinical experience. The pretreatment for luting was divided into two groups: one in which all pretreatments of alumina sandblasting, phosphoric acid treatment, and silane treatment were performed (guideline compliance group), and the other in which at least one of the treatments was not performed (guideline non-compliance group). CAD/CAM-produced composite resin crown, coronal survival and related factors were examined using the Kaplan-Meier method and Cox proportional hazards analysis.
Results: The 6-year cumulative survival rate was 93.6% and the success rate was 88.8%. The 6-year cumulative survival rate was 92.7% in the guideline compliance group, which was significantly higher than 79.5% in the guideline non-compliance group. Regarding factors affecting survival time, the Cox proportional hazard analysis found that the complete or pretreatment of the adhesive pretreatment had a significant relationship with the survival time.
Conclusion: Adhesive pretreatment for luting is important for obtaining long-term longevity, suggesting that premolar CAD/CAM-produced composite resin crowns may be sufficient for clinical use.
View full abstract