Invisible reinforcement of uncomplicated coronal fracture using two different fiber-reinforced composites: in-vitro and in-vivo study

Abstract

Purpose To evaluate in vitro and in vivo the fiber-reinforced composite (FRC) in the restoration of uncomplicated coronal fracture of upper permanent central incisors. Materials and Methods (a) In vitro: standardized one-third coronal sections were prepared on 30 extracted human maxillary central incisors with close similarity. The specimens were embedded perpendicular to standard molds of self-curing acrylic resins and randomly assigned into three groups (n = 10/each). Group I: restored with glass FRCs and particulate filler composite (PFC), group II: restored with polyethylene FRCs and PFC, and group III (control): restored with PFC. In the groups I and II, a shallow palatal preparation was prepared. The fracture resistance was determined by a universal testing machine. Failure modes were optically magnified and analyzed. (b) In vivo: a clinical prospective study was performed on 27 patients, aged 9–18 years, presented with Ellis class-II fractures of maxillary central incisors. The teeth were randomly divided into three groups (n = 10 teeth/each) as in the in-vitro study. All patients were followed-up clinically and radiographically at 3, 6, 9, and 12 months. Results In vitro: the glass FRCs recorded the high fracture strength values, followed by polyethylene FRCs, and PFC and the difference was significant among them (P ≤ 0.05). Mode of failures showed no significant difference among them (P ≤ 0.05). However, in-vivo results showed 100% clinical success for FRCs groups compared with 80% for PFC, but the difference was not significant (P ≥ 0.05). The radiographic findings showed 100% success. Conclusion Only in the in-vitro study, the invisible substructure of glass FRCs followed by polyethylene FRCs seems to be significantly effective in restoration of Ellis class-II fractures of permanent incisors and promising to improve load-bearing capacity.