Fatigue failure of anterior teeth without ferrule restored with individualized fiber-reinforced post-core foundations

Objectives: The aim was to explore the survival of extensively damaged anterior teeth without ferrule restored with different fiber-reinforced composite (FRC) post-core foundations and composite crowns. Materials and methods: Sixty extracted upper central incisors were decoronated and randomly divided into four groups (n = 15). After endodontic treatment, the specimens were restored with different individualized fiberreinforced post-core foundations as follows: control group (CTRL): multiple unidirectional FRC-post + dualcure composite-core, PFC: multiple unidirectional FRC-post + packable short fiber-reinforced composite (SFRC), BPFC: Bioblock technique with only packable SFRC, BFFC: Bioblock technique with only flowable SFRC. After core build-up, the teeth were finalized with adhesively luted CAD/CAM composite crowns. Cyclic isometric loading (5 Hz) was applied at 100 N for 5000 cycles, and then 200 N and 300 N for 15,000 cycles each in a fluid chamber. The specimens were loaded until fracture occurred or when a total of 35,000 cycles were reached. Kaplan-Meyer survival analysis was conducted, followed by pairwise log-rank post hoc comparisons (MantelCox). Results: The survival rates of the control (8279 cycles) and PFC (6161 cycles) were significantly higher compared to BPFC (3223 cycles) and BFFC (2271 cycles) (p < 0.05). Regarding fracture pattern, nearly all specimens fractured in a restorable manner. Conclusions: For restoring extensively damaged anterior teeth, multiple unidirectional FRC posts are recommended. Clinical relevance: Although different FRC post/core systems are available for the restoration of damaged root canal treated anterior teeth, multiple unidirectional FRC posts tend to be a good option when the ferrule is missing.

Automated summary

The study found that for extensively damaged anterior teeth without ferrule, using multiple unidirectional FRC posts is recommended for better survival rates. There were significant differences in survival rates among the groups, and almost all specimens fractured in a restorable manner.