Effect of saliva contamination on bond strength of resin luting cements to dentin

Abstract 

Objectives

This study examined the effect of saliva contamination on the microtensile bond strength (μTBS) of resin luting cements to dentin.

Methods

For RelyX ARC (ARC, 3M ESPE), dentin surfaces were etched with 32% phosphoric acid. The subgroups were: ARC-control (uncontaminated), ARC-I (saliva contamination, blot-dried), ARC-II (saliva contamination, rinse, blot-dried) and ARC-III (saliva contamination, rinse, re-etch, rinse, blot-dried). For Panavia F 2.0 (PF, Kuraray), the subgroups were: PF-control (uncontaminated), PF-I (saliva contamination, dried), PF-II (saliva contamination, rinse, dried), PF-III (primer, saliva contamination, dried), PF-IV (primer, saliva contamination, dried, primer re-applied) and PF-V (primer, saliva contamination, rinse, dried, primer re-applied). Composite blocks were luted onto dentin using the two cements. Bonded specimens were sectioned into 0.9mm×0.9mm beams for μTBS testing. Representative fractured beams were prepared for fractographic analysis.

Results

For ARC, salivary contamination of etched dentin (ARC-I) significantly lowered bond strength (p=0.001). Rinsing saliva off with water (ARC-II) restored bond strength to control level. Re-etching dentin surface after rinsing (ARC-III) resulted in the lowest bond strength (p<0.001). For PF, salivary contamination of dentin before (PF-I) and after application of primer (PF-III and PF-IV) significantly lowered bond strength (p<0.001). Rinsing saliva off with water and re-application of primer (PF-II and PF-V) improved bond strength.

Conclusion

Saliva contamination during luting deteriorated the bond quality of resin cements. Decontamination by rinsing with water was most effective in restoring the bond strength of RelyX ARC. Decontamination by water-rinsing and primer re-application after rinsing improved the bond strength of Panavia F 2.0.

Keywords: Resin cement, Saliva, Contamination, Microtensile bond strength, Dentin