Reaction of rat connective tissue to mineral trioxide aggregate and diaket

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket.</p> <p>Methods</p> <p>Each of the materials was placed in dentine tubes and implanted subcutaneously in the dorsal connective tissue of 21 Wistar albino rats. Tissue biopsies were collected 7, 30, and 60 days after the implantation procedure. The specimens were processed and stained with hematoxylin and eosin and examined microscopically. After determining inflammatory cell numbers in sections from each specimen, inflammatory reaction scores were defined as follows: 0; no or few inflammatory cells (no reaction), 1; less than 25 cells (mild reaction), 2; 25 to 125 cells, (moderate reaction), and 3; 125 or more cells (severe reaction). Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests.</p> <p>Results</p> <p>There were statistically significant differences in the median inflammatory cell numbers throughout the three test periods, with the most severe degree of inflammation observed at the one-week period. Few cases of necrosis were observed with WMTA. Diaket exhibited the most severe degree of inflammation and necrosis. After 30 days, both materials provoked moderate inflammatory reaction. The eight-week period showed the least severe degree of inflammation in all groups.</p> <p>Conclusions</p> <p>It was concluded that WMTA exhibits a more favourable tissue response compared with Diaket which induced more severe inflammatory reaction than WMTA and the control.</p

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

MTA and calcium hydroxide for pulp capping MTA e hidróxido de cálcio para proteção pulpar direta

This study evaluated the biocompatibility of mineral trioxide aggregate (MTA) after direct capping of exposed pulp tissue in dog's teeth. Class I cavities were prepared in 26 teeth from 3 adult dogs. MTA was applied over the exposed pulp in 13 teeth and paste of calcium hydroxide plus distilled water (control) was applied in the remaining 13 teeth. After 90 days, the animals were killed; the maxilla and mandible were dissected and sectioned to obtain individual roots. The samples were processed histologically. The pulp and periapical response observed with the use of MTA was similar to that of calcium hydroxide paste. In all specimens, there was a dentin bridge obliterating the exposure, an intact odontoblastic layer, no inflammatory cells, normal connective pulp tissue, normal apical and periapical regions and no bone tissue changes. Similar to calcium hydroxide, MTA presented excellent response when used for direct pulp capping.<br>O objetivo deste trabalho foi avaliar a biocompatibilidade do agregado de trióxido mineral (MTA), após proteção pulpar direta em dentes de cães. Foram preparadas cavidades de Classe I, em 26 dentes de 3 cães adultos. O MTA foi aplicado sobre 13 dentes e a pasta de hidróxido de cálcio (grupo controle) foi aplicada sobre os 13 dentes remanescentes. Após 90 dias, os animais foram mortos, a maxila e a mandíbula foram dissecadas e os dentes foram seccionados para obtenção de raízes individualizadas. Os espécimes foram processados histologicamente. A resposta do tecido pulpar e periapical foi semelhante para o MTA e o hidróxido de cálcio. Em todos os espécimes havia ponte de dentina obliterando o local da exposição pulpar, camada odontoblástica íntegra, ausência de células inflamatórias, tecido pulpar normal, e ausência de alterações na região periapical e óssea. Da mesma maneira que o hidróxido de cálcio, o MTA apresentou excelente biocompatibilidade quando usado para proteção pulpar direta