Ageing of TotalFill BC Sealer and MTA Fillapex in Simulated Body Fluid

Objective: The bioactivities of TotalFill BC and the MTA Fillapex sealers were evaluated. Methods: Sixty horizontal root sections were enlarged to size 5 Gates Glidden and randomly divided into six groups (n=10 in each group). In Groups 1-3, sections were filled with TFBCS, while sections in groups 4-6 were filled with MTAFS. Specimens from groups 1 and 4 were soaked in simulated body fluid (SBF) for one day, those from groups 2 and 5 for one week, and those from groups 3 and 6 for two months. All specimens were processed for scanning electron microscope (SEM) examination. Apatite precipitation on sealer and sealer- dentine interfaces was quantified using image analysis software (ImageJ). Energy dispersive X-ray (EDX) was used to analyse calcium (Ca) and phosphate (P) contents of surface precipitation on which calculation of the calcium phosphate (Ca/P) ratio was based. Results: TFBCS samples, regardless of the duration of SBF soaking, yielded a significantly higher surface area of precipitation compared to MTAFS (P<0.05); such precipitation increased over time, and the differences among the three time-points were also statistically significant. Following one day of SBF soaking, MTAFS samples showed only limited precipitation that started to appear after one week. EDX showed that Ca content and the Ca/P ratio of surface deposits on TFBCS samples increased over time with no difference between one week and two months of SBF soaking. The Ca content and Ca/P ratio of surface deposits on MTAFS were significantly lower than that of TFBCS samples regardless of the SBF soaking time. Conclusion: Ageing TotalFill BC sealer in SPF can induce considerable apatite formation. In addition, the TotalFill BC sealer surface showed high Ca2+ ion release as reflected by the formation of apatite with a high Ca/P ratio. These bioactivity features increased over time. In comparison, the MTAFS appears to have lower and delayed bioactivity.