Desenvolvimento de membranas de acetato de celulose incorporadas com aditivos funcionais para tratamentos regenerativos periodontais

Abstract

The present work evaluated the effects of the incorporation of functional additives, namely sodium carboxymethyl lignin, tetracycline and calcium glycerophosphate, in cellulose acetate membranes for application in regenerative processes. These processes, called guided tissue regeneration (RTG) and guided bone regeneration (ROG), are used in several clinical situations to facilitate the repair of bone and periodontal defects. Five different cellulose acetate membranes with different combinations of functional additives obtained by the casting method were characterized in terms of its visual appearance, morphology, structure, thermal properties, mechanical performance and evaluation of swelling and mass loss at physiological pH. On the visual aspect it is noticed that the membranes are completely opaque and flexible, being broken only when subjected to folding. MEV images showed that the membranes have a highly porous structure with different pore size distributions depending on the additive grafted, but with an estimated average pore size of 5 μm, well below the size (175 μm) of the fibroblasts that need to be excluded. The thermogravimetric curves showed increased thermal stability by incorporation of the additives and the DSC curves showed the presence of two endothermic events. The tensile test showed that although the membranes exhibit little tensile strength and low percentage of deformation they have enough mechanical resistance to act as a physical barrier throughout the periodontal regenerative process. The tests carried out at physiological pH showed that the presence of the additives gives a higher hydrophilic character to the membranes. Its water absorption and retention capacity is increased and require a long period of time for total mass loss, that permit the membranes are be classified as non-absorbable. The results showed that membranes can be used as a physical barrier in regenerative treatments, but mainly in periodontal reconstitutions.