Immediate and delayed solubility of mineral trioxide aggregate and Portland cement

This study investigated the solubility of mineral trioxide aggregate (MTA) and Portland cement since its mixture until 672 hours, by means of two complimentary methods. Metal ring molds filled with the cements were covered with distilled water and, at each experimental time (3, 24, 72, 168, 336 and 672 hours), were weighed as soon as the plates in which the samples have been placed. Empty rings served as the control group (n=8). Mean weight gain and loss was determined and analyzed statistically by two-way ANOVA and Tukey's test for all pairwise comparisons. Only Portland cement showed less than 3% weight loss through 24 hours. Detached MTA residues were heavier than those of Portland cement over the 3 to 168 hours. The weight of MTA rings increased more than that of Portland rings within 672 hours (p=0.05). The findings of the present study indicate that, in an aqueous environment MTA is more soluble than Portland cement and exceeds the maximum weight loss considered acceptable by ISO 6876 standard (2001)

Healing of root perforations treated with Mineral Trioxide Aggregate (MTA) and Portland cement Reparo de perfurações radiculares tratadas com Agregado Trióxido Mineral (MTA) e cimento Portland

Fourteen root perforations were performed for microscopic evaluation of the repair of interradicular tissue in dogs' teeth. These perforations were accomplished at low-speed with a STP 58 bur at the cervical third of the mesial root toward the furcation under irrigation with saline solution, followed by immediate sealing with ProRoot MTA, MTA-Angelus and white Portland cement. The dogs were killed after 90 days, revealing good results. The Kruskal-Wallis test did not demonstrate any statistically significant difference. It was concluded that the three materials showed good sealing in mineralized tissue, with complete closure, and they were free of inflammation in most teeth.<br>Avaliou-se o reparo de perfurações em dentes de cães, tratadas com ProRoot MTA, MTA Angelus e cimento Portland branco. As perfurações foram feitas na região de furca de premolares, superiores e inferiores, com broca STP 58 sob refrigeração com soro fisiólogico. Os animais foram mortos após 90 dias e os dentes foram preparados para análise microscópica pela coloração da hematoxilina e eosina. Os três materiais propiciaram o selamento da perfuração com tecido mineralizado e o teste de Kruskal-Wallis demostrou não haver diferença estatística entre eles