Comparison of Fracture Strength of Three Different Restorative Protocols for the Management of Re-Fracture of Teeth with Uncomplicated Crown Root Fractures

INTRODUCTION: Fragment reattachment has been suggested as an interim emergent treatment modality for crown root fractures of permanent incisors. However, they may re-fracture leading to fragment dislodgement, even with in the acute phase. Hence, this in vitro study aimed to compare the efficacy of three management protocols of re-fracture of teeth with uncomplicated crown root fractures.
METHODS: Sixty mandibular bovine incisor teeth were selected and were fractured to simulate uncomplicated crown root fracture. Fragments were rehydrated and reattached as per the etching‒bonding protocol and stored in artificial saliva. They were refractured and randomly allocated to three groups for rebonding: Group-I(reattachment without rehydration), Group-II-(rehydration and reattachment), and Group-III-(restoration using composite). Universal testing machine was used to evaluate the force required to fracture them.
RESULTS: Group III showed the highest mean force (338.95±81.94N, 95%CI- 300.60, 377.30), followed by Group II (255.56±58.19N, 95%CI-198.32, 252.79). The lowest value of force required to fracture was observed in Group I (141.76±60.16N, 95% CI-113.60, 169.92).
DISCUSSION AND CONCLUSION: The force required for fracture was greater in the teeth where composite restoration was done instead of re-bonding of dislodged crown-root fragment. Among the reattachment groups, the force required to fracture was greater when rehydration was performed.

Keywords: Crown root fractures, fracture resistance, fragment reattachment, rehydration, traumatic dental injuries