Chin J Dent Res 10 (2007), No. 2 (14.12.2007)
Effect of Storage Time on Microtensile Bond Strength of Short Glass Fibre-Reinforced Composite
Garoushi, Sufyan / Vallittu, Pekka K. / Lassila, Lippo V. J.
Objective: To evaluate the microtensile bond strength (µ-TBS) of short glass fibre-reinforced composite (FC) to dentine and the reliability of two adhesive systems and influence of water storage on bond strength.
Methods: Experimental FC was prepared by mixing short glass fibres with a fraction of 22.5 wt% and IPN-resin 22.5 wt% with silane-treated particulate fillers 55 wt% using a high-speed mixing machine. FC composite and conventional restorative composite resins (PFC) (Grandio; control) were bonded incrementally to flat, midcoronal dentine from 40 human molars, using two different adhesives systems (total-etch [Scotchbond] and self-etch [Futurabond]). Teeth were sectioned both mesiodistally and buccolingually to obtain multiple bonded beam specimens. The specimens were stored in water at 37°C for 1 month or 6 months before being tested in tension at a crosshead speed of 0.5 mm/min until failure. The failure mode was analysed by SEM. The data were analysed using ANOVA.
Results: The bond strength of experimental FC did not differ (p > 0.05) from conventional PFC. Bond strength values were significantly higher (p < 0.05) with the total-etching system than with the self-etching system. Water storage decreased the bonding values.
Conclusion: Short-FC with semi-IPN polymer matrix revealed similar bonding capacity to conventional PFC.
Keywords: fibre-reinforced composite, microtensile bond, restorative composite