Resumo: o objetivo deste trabalho foi avaliar, histometricamente, o processo de cura de defeitos periodontais tipo retrações gengivais, criados cirurgicamente nos caninos superiores de cães, após serem tratados pela técnica de regeneração tecidual guiada utilizando-se de membranas reabsorvíveis de ácido poliláctico (Guidor@). Após a criação cirúrgica, os defeitos ficaram sujeitos a acúmulo de placa por três meses. Terminado este período, os defeitos bilaterais semelhantes foram aleatoriamente designados a receber os seguintes tratamentos: regeneração tecidual guiada (Grupo teste) e retalho reposicionado coronariamente (Grupo controle). Após três meses de cicatrização, foram obtidas as .peças para a análise histológica. Foram avaliados os seguintes parâmetros histométricos: cobertura radicular, extensão do epitélio sulcular e juncional, adaptação conjuntiva, novo cemento, novo osso e extensão do defeito. A porcentagem de recobrimento
radicular. observada nos grupos teste e controle foi, 90.6% e 91.9%, respectivamente. As médias obtidas no grupo teste e controle, respectivamente, foram: novo cemento, 3,8 ::!:: 1,5mm e 2,4 ::!:: 0,3mm; extensão do epitélio sulcular e juncional, 1,9 ::!:: 0,8mm e 3,0 ::!:: 0,9mm; a.daptação conjuntiva, 0,1 ::!:: O,lmm e 0,8 ::!:: 0,5mm; novo osso, 1,1 ::!:: 0,5mm e 1,4 ::!:: 0,2mm. Não foram encontradas diferenças estatisticamente significantes entre os grupos, em nenhum dos parâmetros avaliados. Considerando os limites deste estudo, pode-se concluir que ambos os procedimentos resultaram numa resposta favorável quanto ao recobrimento radicular e proporcionaram regeneração periodontal na parte apical do defeito, sem diferenças estatisticamente significantes entre os tratamentos Ver menos

Abstract: The goal of this investigation was to evaluate histologically and histometrically the healing process of gingival recessions treated by guided tissue regeneration with polylactic acid membranes (GTR-group) and to compared it to that obtained with coronally positioned flaps (CPF-group). Five mongrel dogs were used in the experiment. Gingival recessions were surgically created on the bucal aspect of the upper cuspids after removing the soft and hard tissue using hand instruments. The created defects, measuring 5x7 mm, were exposed to plaque accumulation for a period of 3 months. After this period, the contralateral defects were randomly
assigned to the GTR-group or the CPF-group. After 3 months ofhealing, the dogs were sacrificed and the blocks containing the experimental specimens were processed for histological analysis. The histometric parameters evaluated were: length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone and defect coverage. The extension of the sulcular andjunctional epithelium was 1.9:t 0.8 mm for the GTR-group and 3.0:t 0.9 mm for the CPF-group (P=0.16). The new connective tissue ,!djacent to the root without cementum formation was 0.1 :t 0.1 and 0.8 :t 0.5 mm in the GTR-group and CPF-group, respectively (p=0.05). The new cementum formation observed was 3.8 :t 1.5mm and 2.4 :t 0.3 mm in the GTR-group and CPF-group, respectively (P=0.16). Bone formation was 1.1 :t 0.5 mm in the GTR-group and 1.4:t 0.2 mm in the CPF-group (P=0.53). Histologically, the defect coverage observed with the two techniques was similar, 90.6% and 91.9% for the GTR-group and the CPF-group, respectively. No statistical differences in any ofthe parameters evaluated could be detected. Within the limits of this study it can be concluded that both procedures resulted in a favorable healing response with no significant difference between the treatments Ver menos