Regenerative endodontic procedure of immature permanent teeth with leukocyte and platelet rich fibrin: a multicenter controlled clinical trial.

Abstract

AIM\nThe aim of this non-randomized, multicenter controlled clinical trial was to evaluate the impact of leukocyte and platelet rich fibrin (LPRF) on regenerative endodontic procedures (REP) of immature permanent teeth in terms of peri-apical bone healing (PBH) and further root development (RD).\n\n\nMETHODOLOGY\nHealthy patients between 6-25 years with an inflamed or necrotic immature permanent tooth were included and divided between the test (= REP+LPRF) and control (= REP-LPRF) group, depending on their compliance and the clinical setting (university hospital or private practice). After receiving REP+/-LPRF, the patients were recalled after 3, 6, 12, 24 and 36 months. At each recall session the teeth were clinically and radiographically (by means of a peri-apical radiograph (PR)) evaluated. A cone beam computed tomography (CBCT) was taken pre-operatively, 2 and 3 years post-operatively. PBH and RD were quantitatively and qualitatively assessed.\n\n\nRESULTS\nTwenty-nine teeth with a necrotic pulp were included from which 23 (9 test, 14 control) were analyzed. Three teeth in the test group had a flare-up reaction in the first year post REP. Except for 2 no shows, all the analyzed teeth survived up to 3 years post REP and in case of failure apexification preserved them. Complete PBH was obtained in 91.3% and 87% of the cases, based on PR qualitative and quantitative evaluation respectively, with no significant difference between the groups with respect to (wrt) the baseline. The PR quantitative change in RD at the last recall session, wrt the baseline, was not significant (all p-values >0.05) in both groups. The qualitative assessment of the type of REP root healing was non-uniform. In the test group 55.6% of the teeth presented no RD and no apical closure. Only 50% of the 14 teeth assessed with CBCT presented complete PBH. Regarding volumetric measurements on RD 3 years post REP, for the change wrt the baseline in root hard tissue volume (RHTV), mean root hard tissue thickness (RHTT) and apical area, the control group performed significantly in favor of RD than the test group (p= 0.03, 0.003 and 0.05 respectively). For the volumetric change 3 years post REP wrt the baseline in root length and maximum RHTT, no significant difference (p= 0.72 and 0.4 respectively) was found between the groups. The correlation between the PR and CBCT variables assessing RD was weak (root lengthening) to very weak (root thickening).\n\n\nCONCLUSION\nREP-LPRF seems to be a viable treatment option to obtain PBH and aid further RD of necrotic immature permanent teeth. Caution is needed when evaluating REP with PR.