Meizi Eliezer

Regenerative capacity of well-preserved blood clot may be enhanced by biologics like enamel matrix derivative (EMD). This retrospective analysis compares outcomes reported by three centers using different heterografts. Center 1 (C1) treated intrabony defects combining cross-linked heavy weight hyaluronic acid (xHyA) with a xenograft, Center 2 (C2) used EMD with an allograft combination to graft residual pocket. Center 3 (C3) combined xHyA with placement of resorbable polymer membrane for defect cover. Clinical parameters, BoP reduction and radiographically observed defect fill at 12-months examination are reported. The 12-months evaluation yielded significant improvement in PPD and CAL at each center (p<0.001, respectively). Analyses of Covariance revealed significant improvement of all parameters, significantly greater CAL gain disclosed C2 vs. C1 (p=0.006). Radiographic defect fill presented with significantly higher scores for C2 and C3 vs. C1 (P=.003 and =.014; C2 vs. C3 P=1.00). Gingival recession increased in C1 and C3 (P=1.00), while C2 reported no GR after 12-months (C2:C1 P=.002; C2:C3 P=.005). BoP tendency and pocket closure rate shared similar rates. Within limitations of the study, data comparison indicated that xHyA showed similar capacity to enhance regenerative response, as known for EMD. Radiographic follow-up underlined xHyA staying alone role in new attachment formation.

Objectives We previously showed that accelerated degradation of collagen membranes (CMs) in diabetic rats is associated with increased infiltration of macrophages and blood vessels. Since pre-implantation immersion of CMs in cross-linked high molecular weight hyaluronic acid (CLHA) delays membrane degradation, we evaluated here its effect on the number of macrophages and endothelial cells (ECs) within the CM as a possible mechanism for inhibition of CM resorption. Materials and methods Diabetes was induced with streptozotocin in 16 rats, while 16 healthy rats served as control. CM discs were labeled with biotin, soaked in CLHA or PBS, and implanted under the scalp. Fourteen days later, CMs were embedded in paraffin and the number of macrophages and ECs within the CMs was determined using antibodies against CD68 and transglutaminase II, respectively. Results Diabetes increased the number of macrophages and ECs within the CMs (∼2.5-fold and fourfold, respectively). Immersion of CMs in CLHA statistically significantly reduced the number of macrophages (p < 0.0001) in diabetic rats, but not that of ECs. In the healthy group, CLHA had no significant effect on the number of either cells. Higher residual collagen area and membrane thickness in CLHA-treated CMs in diabetic animals were significantly correlated with reduced number of macrophages but not ECs. Conclusions Immersion of CM in CLHA inhibits macrophage infiltration and reduces CM degradation in diabetic animals. Clinical relevance The combination of CLHA and CM may represent a valuable approach when guided tissue regeneration or guided bone regeneration procedures are performed in diabetic patients.