Long-Term Cytotoxicity, pH and Dissolution Rate of AH Plus and MTA Fillapex

Abstract

The aim of the present study was to verify the long-term cytotoxic effects of the MTA Fillapex and to compare them with AH Plus. Dissolution rate and pH were also evaluated. Human osteoblast cells were incubated with elutes of fresh specimens from AH Plus and MTA Fillapex, and with elutes of the same specimens for 4 successive weeks. Elute's pH was evaluated at each time point. A multiparametric cell viability assay was performed. For dissolution rate, ISO methodology was used. The results were analyzed by one-way analysis of variance, complemented with the Tukey post-test (p<0.05). No significant difference was found among the materials when fresh mixed (p>0.05). After 1 week, AH Plus became non-cytotoxic on all three evaluated parameters. Conversely, MTA Fillapex remained severely and mildly cytotoxic over the entire experimental period (p<0.05). The dissolution rate of AH Plus was significantly lower than MTA Fillapex at all time points (p>0.05). The pH of AH Plus was significantly lower than MTA Fillapex at the second and third week (p<0.05). In the other tested time points no statistical difference was observed.In conclusion, MTA Fillapex remained cytotoxic after 4 weeks and its cytotoxicity may be related to the high dissolution rate of this material.

Microleakage of different root canal sealers in absence of a coronal restorative material

“…Such higher solubility might lead to sealer particles release, creating gaps and failures in sealer/root canal walls interface, allowing microleakage of fluids and microrganisms within the root canal system. 27 Despite the lower levels of coronal microleakage at the 15-day period, the results for Sealapex were statistically similar to MTA Fillapex at both periods of analysis. Calcium hydroxide-based root canal sealers, as Sealapex, are used in endodontic therapy to improve apical repair, as they release calcium ions and promote deposition of mineralized tissue at their site of action.…”

“…26,27 This root canal sealer presented a solubility higher than 3%, which is not in accordance with the Specification N.º 57 of the ANSI/ADA, 24 compromising other physico-chemical properties, as sealing ability. Such higher solubility might lead to sealer particles release, creating gaps and failures in sealer/root canal walls interface, allowing microleakage of fluids and microrganisms within the root canal system.…”

Mineral Trioxide Aggregate: A review of clinical usage and investigations of the effects of modifying particle size

“…In a four-week study, MTA Fillapex showed continual cytotoxicity. 29,259 Similarly, iRoot SP showed continual cytotoxicity in a six-week study. 233 Both MTA sealers were more cytotoxic than AH Plus over the same testing period.…”

“…259 An alternative method would be to place freshly mixed MTA immediately into a simulated root-end filling that is then exposed to the testing culture. 257 This prevents the disintegration of the MTA.…”

“…This is especially important for MTA sealers which have high solubility. 259 These materials should be tested over longer periods of time. Samples can be prepared, placed into a simulated root-end filling, allowed to cure in water for 1, 2 or 3 weeks, and then placed into cell culture.…”