ABSTRACT
OBJECTIVES: The present study investigated the effects of various irrigation activation techniques, including laser-activated irrigation using a laser with a novel tip design (photon-induced photoacoustic streaming, PIPS) on the bond strength of an epoxy resin-based sealer to root dentin. MATERIALS AND METHODS: Seventy-two single-rooted human mandibular premolars were prepared using the rotary system to size 40 and randomly divided into four groups (n = 18) according to the final irrigation activation technique used as follows: conventional irrigation (CI), laser-activated irrigation with PIPS (LAI-PIPS), passive ultrasonic irrigation (PUI), and sonic irrigation (SI) with 5 mL of 17 % EDTA and 2.5 % NaOCl. The root canals were then obturated with gutta-percha and AH PlusJet sealer. A push-out test was used to measure the bond strength between the root canal dentin and the sealer. The data were analyzed using the two-way analysis of variance and least significant difference (LSD) post hoc tests (P = 0.05). RESULTS: The LAI-PIPS and PUI resulted in higher push-out values compared to CI and SI (P < 0.05). There were no statistically significant differences between CI and SI (P = 0.978) and between LAI-PIPS and PUI (P = 0.051). There was a statistically significant interaction between the final irrigant activation techniques used and root canal thirds (P < 0.05). A chi-square test revealed no significant differences in the failure mode within the groups (P > 0.05). CONCLUSIONS: The use of LAI-PIPS and PUI can provide higher bond strength of resin sealer to root dentin compared to CI and SI techniques. CLINICAL RELEVANCE: The activation of the irrigant and the creation of the streaming have a positive effect on the bond strength of the resin sealer to root dentin.
