A 3-year clinical evaluation of endodontically treated posterior teeth restored with two different materials using the CEREC AC chair-side system

Statement of problem: The introduction of polymer-infiltrated ceramic network (PICN) materials may provide more options for dentists in restoring short clinical crowns and extensively damaged posterior teeth, but clinical data for their performance are lacking.

Purpose: The purpose of this clinical study was to compare the 3-year performance and survival rates of PICN material with those of conservative ceramic onlay restorations for endodontically treated posterior teeth using the CEREC AC chair-side system.

Material and methods: A total of 101 onlay restorations of endodontically treated posterior teeth using the CEREC AC chair-side system were provided in 93 participants. The 101 teeth were divided into 2 groups: Vita Enamic group and Vitablocs Mark II group. Using the modified US Public Health Service quality evaluation system, 2 calibrated evaluators examined the performance of the onlay restorations over 3 years. The Kaplan-Meier method was adopted to analyze the survival rate of restorations (α=.05). The log rank test was used to compare the survival rates of the 2 groups. The Fisher exact test was performed to detect differences in the success rates for extensively damaged teeth and short clinical crown restorations between the 2 groups. The Silness and Löe gingival index was also recorded.

Results: The restoration survival rates in the 2 groups were 97.0% (Vita Enamic) and 90.7% (Vitablocs Mark II) (P>.05). Five failures were recorded (4.95%). These failures were caused by restoration debonding (60%), ceramic fractures (20%), and tooth fractures (20%). There were no significant differences between the success rates of restoring extensively damaged teeth and short clinical crowns between the 2 groups (P>.05). The periodontal condition of 25% of participants was improved 3 years after the onlay restorations.

Conclusions: Onlay restorations of endodontically treated posterior teeth with Vita Enamic using the CEREC AC chair-side system are clinically promising prosthodontic alternatives, with a survival rate of 97.0% after 3 years. More research is needed to verify the results of this study.