Effects of oxalate desensitizer with different resin cement-retained indirect composite inlays on fracture resistance of teeth.

Purpose: This study investigated whether the tubular occluding effect of oxalate desensitizer (OX) during adhesive cementation (three resin cements) influenced fracture resistance of teeth restored with adhesive inlays.

Materials And Methods: Ninety intact maxillary premolars were randomly divided into 9 groups of 10 each. The two control groups were Gr 1, intact teeth and Gr 2, mesio-occlusodistal preparation only. In six experimental groups, the composite inlays were cemented with ED Primer II/Panavia F 2.0, Excite DSC/Variolink II, and One-Step Plus/Duolink according to manufacturers' instructions (Groups 3, 5, and 7, respectively) or with OX during cementation (Groups 4, 6, and 8, respectively). In Group 9, inlays were cemented with a resin cement without adhesive system. After thermocycling, fracture strength was tested. The data were analyzed using two-way and one-way ANOVA and LSD post hoc tests (α = 0.05).

Results: Fracture resistance of the six groups were significantly affected by OX (p = 0.002) but not by the resin cement type (p > 0.05). The interaction of the two factors was statistically significant (p = 0.052). A statistically significant difference between all groups was found (p < 0.001). The mean fracture resistances (N) were: Gr1 = 1168 ± 157,(a) Gr2 = 360 ± 110,(d) Gr3 = 1026 ± 188,(b) Gr4 = 887 ± 143,(c) Gr5 = 1007 ± 132,(b) Gr6 = 810 ± 164,(c) Gr7 = 1033 ± 218,(a) Gr8 = 955 ± 147,(ab) Gr9 = 780 ± 86(c) (groups with the same superscript letter indicate statistical similarity).

Conclusions: Combining an OX with three resin cements had a significant negative effect on the fracture resistance of premolars restored with composite inlay cemented with Panavia F2.0 and Variolink II, but it had no significant effect when cemented with Duolink.