Aim: to evaluate solubility, water sorption, calcium (Ca) ions release and bioactivity of different pulp capping materials in simulated dentinal fluid (SDF).
Materials and Methods: Three pulp capping materials were used: Resin-modified calcium silicates (RMCS), White MTA (W-MTA) and Light-cured calcium hydroxide (LC-Ca (OH)2. The different materials’ pastes were prepared according to the manufacturer’ instructions in split Teflon mold (8 mm in diameter and 1.6 mm thick). Solubility (according to ISO 6876 and ADA no.96), water sorption (percentage weight variation (âˆ† %) and Ca ions release (by Inductively Coupled Plasma-Atomic Absorption Spectrophotometry) were evaluated in SDF after 1,7,14 and 28days. Distilled water was used as control group. Bioactivity was assessed using Scanning Electron Microscope with dispersive X-ray analysis and X-Ray diffractometer. The collected data were statistically analyzed.
Results: All investigated materials displayed significantly higher solubility in SDF than distilled water at all time intervals (pï€¼0.05). The highest solubility% was recorded in W-MTA in SDF after 1day (19.67± 3.65%). Moreover, higher water sorption values were recorded in SDF, which appeared non-significant at some time intervals. Results also showed significantly higher Ca ions release in SDF from all materials at all time intervals except for RMCS and W-MTA at day 7. Surface of RMCS and W-MTA showed apatite formation after 1 and 7days immersion respectively. Meanwhile, LC-Ca (OH)2 showed the least bioactivity.
Conclusions: In order to closely mimic the clinical conditions, SDF may be used as alternative to distilled water, suggested by the ADA and ISO specifications, for testing solubility and water sorption of pulp capping materials. Also, the media used and the chemical nature of pulp capping materials have an influence on the pattern of calcium ions release and type of precipitated compounds, which affects the bioactivity of these materials.
Bioactivity, Calcium ions release, Calcium silicate, Solubility, Water Sorption.