College of Stomatology, Hospital of Stomatology, Guangxi Medical University, Nanning, Guagnxi, China. Department of Stomatology, Harbin Institute of Technology Hospital, Harbin, HeiLongjiang, China. Department of Pediatric Dentistry, Jinan Stomatology Hospital, Jinan, 250001, Shandong Province, China. Department of Pediatric Dentistry, Jinan Stomatology Hospital, Jinan, 250001, Shandong Province, China. firstname.lastname@example.org.
BACKGROUND The effectiveness of platelet concentrates in promoting root development of necrotic immature permanent teeth is unclear. The present study evaluated whether the platelet concentrate protocol was superior to the traditional blood clot protocol in regeneration therapy. METHODS We searched Electronic databases, such as PubMed, Cochrane Library, ClinicalTrials and EMBASE. Randomized controlled trial studies, cohort studies, case-control studies and cross-sectional
studies were included, in which platelet-rich concentrates were tested for periapical healing and root development, with the blood clot treatment protocol as the control group. Clinical and radiographic outcomes were considered. Selected articles were assessed for risk of bias. Pooled risk ratios (risk ratio, RR) were calculated for clinical success, responses to cold and electric pulp tests, periapical lesions, apex closure, root lengthening, and thickening of the dentin walls. Subgroup meta-analysis were conducted according to the type of platelet concentrate used. RESULTS Of the 1272 screened studies, 13 randomized controlled studies, 2 case-control studies and 1 cohort study were selected, in which 465 immature necrotic permanent teeth, particularly incisors and premolars, were treated. Of these 465 teeth, 457 (98.2%) in both the control and experimental groups remained clinically asymptomatic for the entire study duration, whereas eight (1.8%) showed signs and symptoms of failure, including spontaneous pain, sensitivity to percussion or reinfection. Compared with control teeth, teeth treated with PRP achieved better apical healing than BC group (RR 1.13, 95% CI 1.01-1.26, P = 0.03), and teeth treated with platelet concentrates showed improved apical closure (RR 1.04, 95% CI 0.86-1.25, P = 0.69), root lengthening (RR 1.01, 95% CI 0.74-1.39, P = 0.93), and thickening of the dentin walls (RR 1.35, 95% CI 0.95-1.93, P = 0.09), although these differences were not statistically significant. CONCLUSIONS Platelet concentrates can be used as successful scaffolds for regenerative endodontic treatment of necrotic immature permanent teeth, and PRP as a scaffold may achieve better periapical healing of teeth with periapical inflammation, although they did not differ significantly from conventional blood clot scaffolds in development of the root.