Evaluation of volumetric and surface stability of calcium silicate-based repair cements at different pHs

The objective of this research was to evaluate the volumetric and surface stability in vitro, to different pH levels, of calcium silicate-based repair cements ready-to-use and powder/liquid exposed.

Sixty human teeth were retro-prepared to a depth of 3 mm and divided into two groups. The first group included powder/liquid cements Biodentine (Septodont, France) and MTA HP (Angelus, Brazil); the second group included ready-to-use cements Bio-C Repair (Angelus, Brazil) and ENDOCEM MTA (Maruchi, Republic of Korea). All samples were submerged in PBS solution with pH levels of 5, 7, and 12. Initially, the materials were evaluated for porosity, marginal adaptation, and volumetric change using micro-CT, and then re-evaluated after 7 and 30 days of exposure to PBS solution. The samples were characterized using SEM/EDS and RAMAN spectroscopy. Statistical evaluation was performed using ANOVA with a 5% significance level.

Bio-C Repair showed significant statistical differences (p < 0.05) at different pHs in 7 and 30 days compared to other materials, being greater in acidic medium. ENDOCEM, regardless of pH, at 30 days showed fewer voids when compared to other repair cements.

This micro-CT study demonstrated that regardless pH, the clinic presentation of calcium silicate-based materials ready-to-use showed higher and loss volumetric than powder/liquid materials at 30 days.

Under neutral pH conditions, calcium silicate-based materials are expected to maintain properties such as bioactivity and low solubility. However, in clinical situations involving infection and inflammation, pH variations can impact the physicochemical properties of these materials regardless of their clinical presentation.