Microscopic and electrophysiological changes on regenerating sciatic nerves of rats treated with simvastatin.

UNLABELLED: Simvastatin is a hypocholesterolemic agent presumed to cause peripheral neuropathy. We arranged an experimental design which focuses on the effect of simvastatin on peripheral nerves and neural regeneration. Sciatic nerve injury was performed at midthigh region of male wistar rats either by clamp compression or fine cut. Electrophysiological and electron microscopical studies were carried out to assess the effect of simvastatin on peripheral nerve and nerve regeneration. There was no difference between the groups that were given simvastatin and standard regimen in the sciatic nerve when electrophysiological measurements were concerned. However, some of the rats that were given simvastatin show reduction in axoplasm density (intensity) of myelinated nerve fibers and prominent vacuolization of myelin sheath according to light and electron microscopic studies. Sciatic nerve compound muscle activation potential measurements of the animals given simvastatin showed that this drug doesn't have a delaying effect on the peripheral nerve recovery time. Electrophysiological measurements showed that simvastatin did not influence nerve regeneration however it was found to induce severe vacuolization of myelin sheath of the sciatic nerve. It was apparent that the drug induces some form of structural dysfunction as myelin changes supported by electron microscopical studies. CONCLUSION: simvastatin was shown to delay regeneration as shown in microscopic studies but still there was no influence on nerve regeneration.

Cytotoxicity evaluation of two different composites with/without fibers and one nanohybrid composite.

In this study, cytotoxicity of two different composites with/without fibers (Adoro/Vectris and SculpturePlus/FiberKor) and one nanohybrid composite (Artglass) were investigated and compared. Composites used in the study were prepared as cylindrical discs of 2 mm depth and 8 mm diameter according to ISO 10993 recommendation. Adoro/Vectris and SculpturePlus/ FiberKor groups were divided into composite, fiber, and composite+fiber groups. Agar diffusion method was employed, and cytotoxicity rankings were determined using lysis index scores. For statistical analysis, Kruskal-Wallis and Mann-Whitney U tests were used. Amongst the composites, Adoro was found to be less cytotoxic than Sculpture Plus and Artglass materials--which were of the same cytotoxicity ranking. Between the fiber and composite materials, the former were found to be more cytotoxic than the latter; in particular, Vectris was found to be more cytotoxic than FiberKor. It was observed that upon combining with the fibers, the cytotoxic effect of the composites increased. This cytotoxicity enhancement was manifested as an additional effect in Adoro/Vectris group but as a synergistic effect in SculpturePlus/FiberKor group.

Evaluation of the marginal gingival health using laser Doppler flowmetry.

The purposes of this study were to compare the gingival blood flow (GBF) in test sites (teeth retaining fixed partial dentures) and control sites (contralateral natural teeth) and investigate whether there is any relationship between clinical indices and GBF values. Twelve healthy subjects (6 females and 6 males) aged 20 to 54 years were enrolled this study. The GBF was measured from the middle point of the marginal gingiva in the test and control sites using laser Doppler flowmetry (LDF). Additionally, plaque index, gingival index and probing depth measurements were recorded. Statistically significant difference (p<0.05) was found between the test and control sites for marginal GBF. In contrast, no significant difference (p>0.05) was found between test and control sites with respect to the clinical indices, except for plaque index. The findings of this study suggest that there is a significant relation between resin-bonded fixed partial dentures with margins located subgingivally and marginal GBF. Clinical indices are helpful to collect information about the clinical health status of gingival tissues, but GBF is a good tool to measure gingival tissue blood flow and assess periodontal health. In conclusion, laser Doppler flowmetry can be used together with clinical indices to evaluate the marginal gingival health.

Evaluation of the marginal gingival health using laser doppler flowmetry

The purposes of this study were to compare the gingival blood flow (GBF) in test sites (teeth retaining fixed partial dentures) and control sites (contralateral natural teeth) and investigate whether there is any relationship between clinical indices and GBF values. Twelve healthy subjects (6 females and 6 males) aged 20 to 54 years were enrolled this study. The GBF was measured from the middle point of the marginal gingiva in the test and control sites using laser Doppler flowmetry (LDF). Additionally, plaque index, gingival index and probing depth measurements were recorded. Statistically significant difference (p<0.05) was found between the test and control sites for marginal GBF. In contrast, no significant difference (p>0.05) was found between test and control sites with respect to the clinical indices, except for plaque index. The findings of this study suggest that there is a significant relation between resin-bonded fixed partial dentures with margins located subgingivally and marginal GBF. Clinical indices are helpful to collect information about the clinical health status of gingival tissues, but GBF is a good tool to measure gingival tissue blood flow and assess periodontal health. In conclusion, laser Doppler flowmetry can be used together with clinical indices to evaluate the marginal gingival health.

Os objetivos deste estudo foram comparar o fluxo sangüíneo gengival (FSG) em sítios teste (dentes retentores de próteses parciais fixas) e sítios controle (dentes naturais contralaterais) e investigar se há alguma relação entre os índices clínicos (IC) e os valores de FSG. Doze indivíduos saudáveis (6 mulheres e 6 homens) com idades entre 20 a 54 anos participaram deste estudo. O FSG foi medido no ponto médio da gengina marginal em ambos os sítios teste e controle utilizando dopplerfluxometria a laser (DFL). Além disso, as medidas referentes ao índice de placa, índice gengival e profundidade de sondagem foram registradas. Foi observada diferença estatisticamente significante (p<0.05) entre os grupos teste e controle para os valores de FSG. Por outro lado, não houve diferença estatisticamente significante (p>0.05) entre os sítios teste e controle com relação aos índices clínicos, exceto para o índice de placa. Os achados deste estudo sugerem que existe uma relação significante entre próteses parciais fixas retidas por resina com margens localizadas subgengivalmente e o FSG marginal. Embora os índices clínicos sejam úteis para coletar informações sobre as condições clínicas dos tecidos gengivais, o FSG é uma ferramenta importante para medir o fluxo sanguíneo tissular gengival e avaliar a saúde periodontal. Em conclusão, a dopplerfluxometria a laser pode ser usada juntamente com índices clínicos para avaliar a saúde gengival marginal.