Influence of human and bovine substrate on the microleakage of two adhesive systems

The aim of this study was to evaluate in vitro the marginal sealing of two adhesive systems and to analyze the influence of human and bovine substrates on marginal microleakage in enamel. Rectangular-shaped class V cavities (4 mm wide x 2 mm high x 2 mm deep) were made as follows: 8 cavities were prepared on the buccal and lingual surfaces of the human teeth with margins located on enamel and 16 cavities were prepared on the buccal surfaces of the bovine teeth. The cavities were randomly assigned to 4 groups of 8 cavities according to the adhesive system and substrate: G1 - Prime & Bond 2.1 (Dentsply)/human substrate; G2 - Adhese (Ivoclar/Vivadent)/human substrate; G3 - Prime & Bond 2.1 (Dentsply)/bovine substrate; G4 - Adhese (Ivoclar/Vivadent)/bovine substrate. The cavities were filled with microhybrid composite resin (Fillmagic) and after polishing/finishing procedures, the teeth were subjected to a thermocycling regimen of 500 cycles with 1-min immersions in water at 55° ±2°C and 5° ± 2°C. Next, the teeth were coated with two layers of nail polish to within 1 mm of the margin, submerged in a 50 percent silver nitrate solution for 2 h, rinsed thoroughly in running tap and immersed in developing solution for 8 h. The restorations were bisected resulting in 16 specimens. Microleakage was observed under a stereomicroscope at x25 and recorded using four-point (0-3) scoring system. The data were analyzed statistically by the Mann Whitney U-test at 5 percent significance level. Leakage was present in all specimens and there was statistically significant difference between the adhesive systems. Adhese self-etching system showed significantly more leakage in both substrates (human - p= 0.0001 and bovine - p= 0.0031). There was no statistically significant difference between human and bovine substrates for either of the adhesive systems based on different bonding mechanisms (Prime & Bond 2.1 - p= 0.6923 and Adhese - p= 0.6109). Neither of the...

Effect of different polishing systems on the surface roughness of microhybrid composites

The use of composite resins in dentistry is well accepted for restoring anterior and posterior teeth. Many polishing protocols have been evaluated for their effect on the surface roughness of restorative materials. This study compared the effect of different polishing systems on the surface roughness of microhybrid composites. Thirty-six specimens were prepared for each composite $#91;Charisma® (Heraeus Kulzer), Fill Magic® (Vigodent), TPH Spectrum® (Dentsply), Z100® (3M/ESPE) and Z250® (3M/ESPE)] and submitted to surface treatment with Enhance® and PoGo® (Dentsply) points, sequential Sof-Lex XT® aluminum oxide disks (3M/ESPE), and felt disks (TDV) combined with Excel® diamond polishing paste (TDV). Average surface roughness (Ra) was measured with a mechanical roughness tester. The data were analyzed by two-way ANOVA with repetition of the factorial design and the Tukey-Kramer test (p<0.01). The F-test result for treatments and resins was high (p<0.0001 for both), indicating that the effect of the treatment applied to the specimen surface and the effect of the type of resin on surface roughness was highly significant. Regarding the interaction between polishing system and type of resin used, a p value of 0.0002 was obtained, indicating a statistically significant difference. A Ra of 1.3663 was obtained for the Sof-Lex/TPH Spectrum interaction. In contrast, the Ra for the felt disk+paste/Z250 interactions was 0.1846. In conclusion, Sof-Lex polishing system produced a higher surface roughness on TPH Spectrum resin when compared to the other interactions.

A doença periodontal como fator de risco para os acidentescerebrovasculares / Periodontal disease as risk factor for cerebrovascular accidents

Introdução: As doenças cardiovasculares, entre elas osacidentes vasculares cerebrais, são responsáveis por 20% detodas as mortes anualmente. Estudos têm evidenciado a associaçãodas doenças periodontais com fatores inerentes ao hospedeirocomo fumo, doenças sistêmicas, estresse, obesidade e outros.Recentemente, a doença periodontal tem sido estudada como fatorde risco para a ocorrência de acidentes vasculares cerebrais.Objetivo: Analisar a relação existente entre acidente vascularcerebral e doenças periodontais, através de evidências da literaturauma vez que ambas as doenças são de grande prevalência nasociedade atual.Conclusão: Apesar de estudos mostrarem evidências da doençaperiodontal como fator de risco para os acidentes vascularescerebrais, os mecanismos biológicos que ligam as duas doençasainda não estão totalmente esclarecidos. Estudos adicionais devemser realizados para esclarecer esta associação, bem como medidaspreventivas devem ser realizadas, visando prevenir a ocorrênciade ambas as doenças.

Levantamento das biopsias da cavidade oral realizadas no Hospital Universitário - Unidade Presidente Dutra-UFMA da cidade de São Luís - MA, no período de 1992 a 2002 / Survey oral cavity biopsies in the University Hospital(UFMA)- Presidente Dutra's Unity, in São Luis, During the periodo of 1992 -2002

O objetivo deste trabalho foi realizar um levantamento das lesões orais do Hospital Universitário - Unidade Presidente Dutra, da UFMA, no período de 1992 a 2002, sendo analisadas 295 fichas clínicas com seus respectivos laudos de diagnóstico histopatológico. Foram avaliadas a freqüência das lesões orais examinadas, a localização anatômica e a distribuição das mesmas quanto ao tipo, sexo e idade. Cada caso foi classificado em onze diferentes grupos, apresentando-se número e índice percentual das lesões de maiores ocorrências. Os resultados demonstraram um predomínio das lesões proliferativas não neoplásicas, com sessenta casos; a hiperplasia fibrosa inflamatória representou a entidade mais comum, sendo o sexo feminino mais envolvido e na primeira década de vida ocorreu um maior percentual de casos