Evaluation of the receptor activator of nuclear factor-κb ligand/osteoprotegerin ratio in the gingival crevicular fluid of patients under periodontal maintenance

Context: Periodontitis is an infectious disease characterized by an inflammatory response and bone resorption, which can cause tooth loss. The bone destruction may be caused by deregulation of the receptor activator of nuclear factor κB/receptor activator of NF-κB ligand/osteoprotegerin (RANK/RANKL/OPG) system, stimulating osteoclastogenesis. After the treatment of the active disease, a formal program of periodontal maintenance is implemented according to each patient needs. Aims: This study aimed to evaluate the RANKL/OPG relation in patients under periodontal maintenance. Setting and Design: Thirty individuals were selected and divided into the test group, comprised of patients who received periodontal treatment and were under periodontal maintenance showing active sites (n = 15), and nonactive sites of the disease (n = 15), and the control group, comprised of healthy periodontium (n = 15). Materials and Methods: The GCF was collected by absorption into paper cones. The measurement of RANKL and OP was performed by xMAP technology and a Luminex 200 flow luminometer system. Statistical Analysis: Data were compared through Kruskal–Wallis test, at 5% significance. Results: There was no intrapatient difference on the RANKL/OPG ratio, but it was significantly lower in the active sites of patients treated of periodontitis, under a maintenance program, compared with the control (P