In vitro evaluation of the influence of ultrasonic activation on physicochemical properties of three endodontic repair materials

Abstract

The influence of ultrasonic activation (UA) on the physicochemical properties of setting time (n = 5), volumetric stability (n = 10), alkalizing activity/calcium ions release (pH/Ca²⁺) (n = 10) and calcium/phosphate-rich substance formation in simulated body fluid (Hank's balanced salt solution; HBSS) of three cements was evaluated: white MTA-Angelus (MTA), MTA Repair HP (MTAHP) and Biodentine (BIO). It was observed that UA influenced the setting times (min) distinctly, delaying the initial setting time of MTA (40.8/64.6) and accelerating that of BIO (35.6/22.4). The final setting time of MTAHP (154.4/114.6) and BIO (64.4/42.4) were also accelerated (p < 0.05). Volumetric reduction was observed in all groups, with MTA/UA being the most volumetrically stable (0.98%); UA did not influence volumetric stability (p > 0.05). All groups exhibited an alkaline pH, with a disadvantage for MTAHP and MTAHP/UA at 24 h, 72 h and 168 h (p < 0.05). All groups showed Ca²⁺ release. The tested cements exhibited a favourable Ca/P ratio on their surface after 28 days.