Effect of different surface treatments and time of repair on shear bond strength of fiber reinforced resin composite material.

Aim: This study evaluates how repair time and surface treatments affect the shear bond strength between fiber-reinforced resin composite and giomer material.Materials and methods: A total of 100 disc samples (2x5mm) of fiber-reinforced composite resin (everX Posterior, GC Corporation, Tokyo, Japan) were prepared and divided into groups based on repair time (immediate and delayed) and surface treatments (five subgroups: subgroup (1): No surface treatment (negative control), subgroup (2): Diamond bur, phosphoric acid etch, universal adhesive, subgroup (3): Diamond bur, phosphoric acid etch, universal adhesive, silane, subgroup (4): Air abrasion, phosphoric acid etch, universal adhesive, (5): Air abrasion, phosphoric acid etch, universal adhesive, silane). A bulk-fill giomer material (Beautifil-Bulk Restorative, Shofu, Kyoto, Japan) was used as a material of repair in 4 mm thickness. After that, samples underwent 5000 cycles of thermocycling and were subjected to shear bond testing using a Universal Testing Machine. Data were analyzed using one-way ANOVA and Tukey post-hoc tests (p≤0.05).Results: Surface treatments have shown statistically significant effect on shear bond strength of repaired fiber-reinforced resin composite at immediate repair where air abrasion groups showed highest SBS while negative control group showed lowest SBS. Different surface treatments have shown non-significant difference at delayed repair groups. Time of repair has shown statistically significant effect on most groups where SBS increased significantly at delayed repair except for A+P+U and A+P+U+Si groups.Conclusion: Time lapse significantly affects repaired fiber reinforced composite durability, while surface treatment and silane having minimal impact.