Tiago Novaes Pinheiro

A scanning electron microscopic study of hypercementosis

The purpose of this study was to evaluate morphological characteristics of teeth with hypercementosis that are relevant to endodontic practice. Twenty-eight extracted teeth with hypercementosis had their root apexes analyzed by scanning electron microscopy (SEM). The teeth were divided according to tooth groups and type of hypercementosis. The following aspects were examined under SEM: the contour and regularity of the root surface; presence of resorption; presence and number of apical foramina, and the diameter of the main foramen. The progression of club shape hypercementosis was directly associated with the presence of foramina and apical foramen obstruction. Cases of focal hypercementosis presented foramina on the surface, even when sidelong located in the root. Circular cementum hyperplasia form was present in 2 out of 3 residual roots, which was the highest proportion among the tooth types. The detection of a large number of foramina in the apical third of teeth with hypercementosis or even the possible existence of apical foramen obliteration contributes to understand the difficulties faced during endodontic treatment of these cases.

Evaluation of subcutaneous and alveolar implantation surgical sites in the study of the biological properties of root-end filling endodontic materials

Objective The aim of this study was to compare two methodologies used in the evaluation of tissue response to root-end filling materials in rats. Material and Methods Forty rats were divided into 4 groups: in Groups I and II (control groups), empty polyethylene tubes were implanted in the extraction site and in the subcutaneous tissue, respectively; in Groups III and IV, polyethylene tubes filled with ProRoot MTA were implanted in the extraction site and in the subcutaneous tissue, respectively. The animals were killed 7 and 30 days after tube implantation, and the hemi-maxillas and the capsular subcutaneous tissue, both with the tubes, were removed. Specimens were processed and evaluated histomorphologicaly under light microscopy. The scores obtained were analyzed statistically by the Kruskal-Wallis test (p<0.05). Results There were no statistically significant differences between the implantation methods (p=0.78033, p=0.72039). It was observed that the 30-day groups presented a more mature healing process due to smaller number of inflammatory cells. Conclusion The present study showed no differences in tissue responses as far as the implantation site and the studied period were concerned. Alveolar socket implantation methodology represents an interesting method in the study of the biological properties of root-end filling endodontic materials due to the opportunity to evaluate bone tissue response.

Transplantes dentários autógenos: uma solução para casos ortodônticos e uma casuística brasileira

Os traumatismos podem induzir desde uma simples trinca de esmalte ate uma avulsao com perda do dente, sem possibilidade de reimplante. Da mesma forma, a perda dentaria decorrente de um traumatismo pode advir de uma fratura ver-tical ou de fraturas radiculares multiplas. Nestes casos, uma avaliacao minuciosa dos dentes e ossos maxilares, condicionada pela idade do paciente, pode levar a oportunidade para um transplante dentario autogeno, tambem conhecido como au-to-transplante. Por sua vez, o reimplante, quando terapeuticamente intencional, passa a ser identifi-cado como transplante autogeno intra-alveolar.Em pacientes anodonticos, a ausencia de pre-molares constitui a manifestacao mais comum nos europeus e seus descendentes diretos, mesmo que em outros paises como o Brasil. As relacoes oclu-sais e dentarias destes pacientes podem levar a um planejamento ortodontico, ortopedico e cirurgico no qual a extracao de pre-molares ou de terceiros molares pode estar indicada. Nesta situacao tam-bem se pode ter a indicacao e a oportunidade para um transplante autogeno.Nos paises escandinavos, o controle da carie dentaria e da doenca periodontal, ha muito tem-po, permitiu que os principais problemas odonto-logicos fossem redirecionados para o traumatismo dentario e ausencia congenita dos dentes por ano-dontia parcial, especialmente de pre-molares. Os transplantes dentarios autogenos sao reali-zados ha mais de 40 anos nos paises escandinavos e o controle dos dentes transplantados, realizado por igual periodo, revela que o aperfeicoamento tecnico e a fundamentacao biologica se encontra-ram, permitindo uma elevada taxa de sucesso na populacao destes paises