evaluation of the effects of subgingival injection of simvastatin on space re-opening after orthodontic space closure in adults

background. this clinical trial evaluated the effect of simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (gi) and clinical attachment loss (cal). methods. 16 females, 25‒40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. the patients were randomly divided into control and experimental groups. in the experimental group, 1.2% simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. the amount of space reopening, gi and cal were measured. results. no serious complications were observed during interventions and follow-up periods. space re-opening was significantly reduced in patients receiving simvastatin (p < 0.001). moreover, gi reduction was significantly greater in simvastatin group compared to the control group (p < 0.001). however, cal did not demonstrate a significant difference between the groups. conclusion. simvastatin may decrease space re-opening after orthodontic space closure in human anterior teeth.