Investigating the Effect of Saliva Contamination at Different Time Intervals on Micro-Shear Bond Strength of Dentin...

The immediate dentin sealing (IDS) approach involves sealing the dentin immediately after tooth preparation and before impression taking. This in vitro study aimed to investigate the effect of saliva contamination at various time intervals on the micro-shear bond strength (µSBS) of dentin sealed using a three-step etch-and-rinse adhesive.

The occlusal coronal third of 40 intact third molars was removed, and IDS was applied using the three-step adhesive OptiBond FL. The bonded samples were divided into four groups and exposed to non-stimulating natural saliva for 0, 7, 14, and 30 days. After saliva exposure, the teeth were rinsed, and the IDS surfaces were conditioned with 50 µm alumina particles for 5 seconds. The standard adhesive procedure was then followed, and resin composite restoration was applied. µSBS was measured using a universal testing machine, and failure modes were recorded. Data were analyzed using Shapiro-Wilk and ANOVA tests (α < 0.05).

The highest bond strength was observed in the control group (25.32 ± 6.70 MPa), while the lowest was in the group exposed to saliva for 30 days (21.93 ± 3.26 MPa). However, no statistically significant difference was found between the groups (P = 0.308). The predominant failure mode in all samples, except for one specimen in the control group, which exhibited mixed failure, was adhesive.

Within the limitations of this in vitro study, saliva contamination for up to 30 days did not significantly affect the µSBS of dentin samples sealed using the IDS method. However, long-term clinical trials are needed to confirm these findings.