Biocompatibilidade de cimentos ortodônticos modificados por resina: Análise morfológica e imuno-histoquímica

Abstract

Objective: To evaluate the biocompatibility of resin-modified glass ionomer (RMGIC) orthodontic cements in rat subcutaneous tissue by morphological and immunochemistry analysis. Materials and Methods: Seventy-five (75) adult male Wistar rats were selected and divided into five groups: Group C (Control); Group CK (Crosslink Orthodontic Band Cement); Group RS (Resilience Light Cure Band Cement); Group RMO (RMO Band Cement) and Group TP (Transbond Plus Light Cure Band). The materials were inserted in the subcutaneous tissue of each rat and after time intervals of 7, 15 and 30 days excisional biopsies were performed. The histological parameters assessed were: inflammatory infiltrate intensity; reaction of multinucleated giant cells; edema; necrosis; granulation reaction; young fibroblasts and collagenization. The immunochemistry analyzed immunostaining of CD68 antibody for macrophages and multinucleated giant cells. The results obtained were statistically analyzed by the Kruskal-Wallis and Dunn test, with value of p<0.05. Results: In the morphological analysis, after 7 days, the groups Resilience, RMO and Transbond showed inflammatory infiltrate more intense than the control group (p=0.004); only Group RMO presented greater expression of multinucleated giant cell reaction (p=0.003) and all groups demonstrated a more intense granulation reaction (p=0.002). The group RMO presented low degree of collagenization after 15 (p=0.008) and 30 days (p=0.014). The immunochemistry analysis revealed that the RMO and Resilience groups showed a higher immunostaining of CD68 (p=0.004) within 7 days and only the RMO group showed a statistically significant difference for this parameter after 15 days compared to the control group (p=0.026). In the period of 30 days, the RMO group had a higher number of multinucleated giant cells (p=0.004). Conclusion: Among the RMGICs evaluated, Crosslink and Transbond provided better tissue response, since it demonstrated a lower level of inflammatory infiltrate and higher degree of collagenization. The RMO demonstrated the lowest level of biocompatibility due to the intense inflammatory with substantial accumulation of macrophage and multinucleated giant cells observed in morphological and immunochemistry techniques.