ABSTRACT
Objective: The aim of this study was to test the null hypothesis that different surface conditioning
(etch and rinse and self-etch) and curing techniques (light cure/dual cure) had no
effect on the shear bond strength of direct and indirect composite inlays. Materials and Methods: A total of 112 extracted human molar teeth were horizontally sectioned and randomly
divided into two groups according to restoration technique (direct and indirect restorations).
Each group was further subdivided into seven subgroups (n = 8) according to bonding agent (etch and rinse adhesives Scotchbond multi-purpose
plus, All-Bond 3, Adper Single Bond and Prime Bond NT; and self-etch adhesives Clearfil
Liner Bond, Futurabond DC and G bond). Indirect composites were cemented to dentin
surfaces using dual-curing luting cement. Shear bond strength of specimens was tested
using a Universal Testing Machine. Two samples from each subgroup were evaluated under
Scanning electron microscopy to see the failing modes. Data was analyzed using independent
sample t-tests and Tukey′s tests. Results: Surface conditioning and curing of bonding agents were all found to have significant
effects on shear bond strength (P < 0.05) of both direct and indirect composite inlays. With direct restoration, etch
and rinse systems and dual-cured bonding agents yielded higher bond strengths than
indirect restoration, self-etch systems and light-cured bonding agents. Conclusions: The results of the present study indicated that direct restoration to be a more reliable
method than indirect restoration. Although etch and rinse bonding systems showed higher
shear bond strength to dentin than self-etch systems, both systems can be safely used
for the adhesion of direct as well as indirect restorations.
Key words:
Adhesive - bonding agent - dentin - shear bond strength