Abstract: OBJECTIVE: There are many kinds of biological scaffolds used for pulp revascularization in clinical practice, and the difference of efficacy between different scaffolds is controversial. The efficacy of nine kinds of biological scaffolds in endodontic revascularization was evaluated by Bayesian network meta-analysis.
METHODS: The computer was used to search the literature in CNKI, VIP, WanFang, China Biomedical Literature Service System, PubMed, Cochrane Library, Web of Science, Embase, and Scopus databases. Randomized controlled trials of different biological scaffolds for the treatment of pulp revascularization in young permanent teeth meeting inclusion criteria were collected from each database up to April 1, 2024. Two researchers sifted through the literature, data collection, sorting and extraction were completed independently, and the quality of the included literature was assessed for risk of bias. A network meta-analysis was performed using BUGSnet1.1.1 package of R4.2.0 software.
RESULTS: A total of 22 studies with 926 affected teeth and 9 different interventions were included in this study. The results of network meta-analysis showed that: (1) Clinical success rate (primary goal): platelet-rich fibrin was superior to blood clot [OR=1.45, 95%CI (0.32, 2.69)], and the top three ranking results were: concentrated growth factor (82.77%) > platelet-rich fibrin (75.38%) > modified platelet-rich fibrin (62.39%). (2) Increased root length (secondary goal): There was no difference among the 7 biological scaffolds at 1-6 months of follow-up (P > 0.05), the top 3 ranking results of rank probability were: concentrated growth factor (86.25%) > platelet-rich plasma (53.76%) > platelet-rich fibrin (51.11%). When followed up for > 6 months and ≤ 12 months, concentrated growth factor was superior to blood clot [MD=9.59, 95%CI(0.52,18.40)], the top 3 ranking results of rank probability were: concentrated growth factor (92.42%) > platelet-rich plasma (56.03%) > platelet-rich fibrin (55.76%). When followed up for more than 12 months, concentrated growth factor was superior to modified platelet-rich fibrin [MD=11.01, 95%CI(0.02 , 22.72)], the top 3 ranking results of rank probability were: concentrated growth factor (86.95%) > platelet-rich fibrin (68.61%) > blood clot combined with collagen (52.5%). (3) Increased root wall thickness (secondary goal): at 1-6 months of follow-up, platelet-rich fibrin was superior to blood clot [MD=11.37, 95%CI (4.74, 17.71)], the top 3 ranking results of rank probability were: platelet-rich fibrin (93.66%) > concentrated growth factor (63.11%) > modified platelet-rich fibrin (50.48%). At > 6 months and ≤ 12 months of follow-up, there was no difference among the 6 biological scaffolds (P > 0.05), the top 3 ranking results of rank probability were: modified platelet-rich fibrin (73.63%) > platelet-rich fibrin (62.36%) > concentrated growth factor (56.25%). When followed up for more than 12 months, there was no difference among the 9 biological scaffolds (P > 0.05), and the top 3 ranking results of rank probability were: blood clot combined with collagen (81.9%) > platelet-rich plasma (62.67%) > modified platelet-rich fibrin (59.49%). (4) Pulp vitality (third-level goal): there was no difference among the 6 biological scaffolds (P > 0.05), and the top 3 ranking results of rank probability were: blood clot combined with collagen (84.22%) > concentrated growth factor (67.71%) > platelet-rich fibrin (48.79%).
CONCLUSION: Existing evidence shows that the clinical success rate of different scaffolds is higher in pulp revascularization, among which platelet-rich fibrin is better than blood clots. In terms of comprehensive comparison of root length and root wall thickness increase, concentrated growth factor performs best in the follow-up period of 1-6 months and > 6 months and ≤ 12 months, while blood clot combined with collagen performs best after follow-up of more than 12 months; concentrated growth factor performs outstandingly in all levels of goals, and may be more conducive to the continued development of the tooth root than other scaffolds, and has great potential in pulp regeneration treatment. Limited by the quality and quantity of literature, the above conclusions still need to be verified by more high-quality studies.

Key words: biological scaffold, pulp revascularization, pulp regeneration, blood clot, platelet-rich plasma, platelet-rich fibrin, concentrated growth factor, network meta-analysis