Aim: Aim of this in vitro study was to evaluate the resistance to fracture of vertically fractured and reattached fragments bonded with fiber-reinforced composites. Materials and methods:Root canals of 45 teeth were prepared, and the teeth were intentionally fractured into two separate fragments. Control groups (n = 15 each) consisted unfractured teeth with instrumented and obturated. Fractured teeth were divided into three groups (n = 15) and were attached using (1) dual-cure resin cement (RelyX U100), (2) dual-cure resin cement and polyethylene fiber (Ribbond), (3) dual-cure resin cement and glass fibers (stick-net). Force was applied at a speed of 0.5 mm/min to the root until fracture.Results and statistical analysis: Group 1 (RelyX U100 group) demonstrated lowest fracture resistance. Group 4 (control group) showed highest fracture resistance followed by group 2 (Ribbond group) and group 3 (Stick-Net groups). Statistically no significant difference was there between groups 2, 3 and 4. Conclusion:Vertically fractured teeth can be treated by filling the root canal space with dual-cure adhesive resin cement or by adding polyethylene fiber or glass fiber to increase the fracture resistance of the reattached tooth fragments, an alternative to extraction.

The acid pretreatment and use of composite resins as the bonding medium has disadvantages like scratching and loss of surface enamel, decalcification, etc. To overcome disadvantages of composite resins, glass ionomers and its modifications are being used for bonding. The study was conducted to evaluate the efficiency of resin reinforced glass ionomer as a direct bonding system with conventional glass ionomer cement and composite resin. The study showed that shear bond strength of composite resin has the higher value than both resin reinforced glass ionomer and conventional glass ionomer cement in both 1 and 24 hours duration and it increased from 1 to 24 hours in all groups. The shear bond strength of resin reinforced glass ionomer cement was higher than the conventional glass ionomer cement in both 1 and 24 hours duration. Conditioning with polyacrylic acid improved the bond strength of resin reinforced glass ionomer cement significantly but not statistically significant in the case of conventional glass ionomer cement. How to cite this article Rao KS, Reddy TPK, Yugandhar G, Kumar BS, Reddy SNC, Babu DA. Comparison of Shear Bond Strength of Resin Reinforced Chemical Cure Glass Ionomer, Conventional Chemical Cure Glass Ionomer and Chemical Cure Composite Resin in Direct Bonding Systems: An in vitro Study. J Contemp Dent Pract 2013;14(1):21-25.