Efficacy of Ribbond and a fibre post on the fracture resistance of reattached maxillary central incisors with two fracture patterns: a comparative in vitro study.

AIM To compare the fracture resistance of maxillary central incisor fragments having two different fracture patterns and re-attached using two different posts - fibre post and Ribbond. MATERIALS AND METHODS Sixty extracted human maxillary central incisors were randomly divided into two groups of thirty samples each. Group A consisted of samples with 'labio-palatal' fracture pattern and Group B with a 'palato-labial' fracture pattern. The crowns of all the samples were sectioned using safe-sided diamond discs. Following cleaning and shaping and sectional obturation, the samples were randomly subdivided into two subgroups of 15 samples each. Prefabricated fibre post (Reforpost, Angelus, Londrina, PR, Brazil) was placed in all samples of Subgroup I, and Ribbond (Ribbond Inc., Seattle, WA, USA) was placed in all samples of Subgroup II. The fragments were re-attached, fracture resistance was tested using Instron Universal Testing Machine, and the failure modes were assessed using a stereomicroscope. RESULTS Group A with a labio-palatal fracture pattern exhibited higher fracture resistance as compared to Group B (palato-labial) in both subgroups. The fibre post (Subgroup I) exhibited higher fracture resistance as compared to Ribbond (Subgroup II). The Ribbond group exhibited significantly more number of repairable failures as compared to fibre post group. CONCLUSION The labio-palatal pattern of fracture is a favourable type of fracture on palatal load application. The fragments re-attached using the fibre post (Reforpost) had a higher resistance to fracture. However, teeth restored with Ribbond posts exhibited 100% repairable failures upon load application. The fracture pattern had no influence on the failure modes.