Fracture Resistance of Endodontically Treated Premolars Restored with Flowable Short Fibre-Reinforced Resin Composite–An In Vitro Study

OBJECTIVE: This in vitro study aimed to evaluate the fracture resistance of endodontically treated premolar teeth restored with flowable short fibre-reinforced resin composite (FSFRRC) at varying depths within the root canals. METHODS: Fifty freshly extracted human single-rooted premolars were divided into 5 Groups (n=10), Group I (IN) intact teeth, Group II (P) restored coronally with resin composite only, Group III, IV and V (FSFRRC2, FSFRRC4, FSFRRC6) based on post space preparation to the respective depths of 2, 4 and 6 mm. Root canal treatment was performed for all the samples of Group II, III, IV, V and the teeth were decoronated 2 mm above cementoenamel junction. Following decoronation, post space preparation was done to the depths of 2, 4, and 6 mm (Group III, IV, V). Teeth were restored with FSFRRC (Groups III-V) intra-radicularly and coronally sealed using resin composite. All the teeth were subjected to fracture strength test using Universal testing machine, and mode of failure was analysed. Kruskal-Wallis test followed by Dunn Post-hoc test was conducted for statistical analysis. Statistical significance was set at P<0.05. RESULTS: All FSFRRC groups showed higher fracture resistance than teeth restored only with resin composite. FSFRRC4 and FSFRRC6 showed significantly (P<0.05) higher fracture resistance than intact teeth and other experimental groups. CONCLUSION: Intra-radicular placement of FSFRRC increased the fractured resistance significantly and may serve as a promising alternative to conventional post systems to rehabilitate endodontically treated teeth.