Comparing the effectiveness of lithium disilicate glass ceramic onlays and full crowns in the restoration of cracked teeth that have undergone root canal therapy

This study compares the effects of lithium disilicate glass ceramic onlays and full crowns in restoring cracked teeth that have undergone root canal therapy, providing a reference for the restoration method of cracked teeth that have undergone root canal therapy.

This study was approved by the hospital’s medical ethics committee, and all patients signed the informed consent form. Patients with cracked teeth who underwent root canal treatment in our hospital from January 2022 to January 2023 were enrolled in this study. According to the inclusion and exclusion criteria, 60 patients were screened and enrolled, with a total of 60 affected teeth. The patients were divided into the onlay group and full crown group at a ratio of 2:3 using the random number table method. Lithium disilicate glass ceramic onlays were used to restore the affected teeth in the onlay group (24 cases), and lithium disilicate glass ceramic full crowns were used to restore the affected teeth in the full crown group (36 cases). At 3, 6, and 12 months after the repair, the restoration effect was evaluated and compared with the modified USPH Standard (the aesthetic, functional, and biological aspects of restorations). According to the biological definition of survival, survival analysis was conducted on the affected teeth in both groups.

At 3, 6, and 12 months after the repair, 85% of cases in the onlay group achieved grade A, while 80% of cases in the full crown group achieved grade A. There was no statistically significant difference in the restoration effects between the onlay group and the full crown group (P > 0.05). The 12-month survival rate of cracked teeth in the onlay group reached 95.65%, and the 12-month survival rate of cracked teeth in the full crown group reached 94.12%. There was no statistically significant difference in the retention of the affected teeth (P > 0.05). There was no significant effect of age, gender, tooth position, dentition, direction of cracks, the number of marginal ridges associated with cracks, or the type of restoration on the survival status of cracked teeth. (P > 0.05).

For cracked teeth that have undergone root canal therapy, the short-term effect of lithium disilicate glass ceramic onlays is comparable to that of full crowns, and both have good short-term effects. Onlays are less invasive and are expected to become an alternative restoration method to full crowns.