Autologous platelet concentrates in alveolar ridge preservation: A systematic review with meta-analyses

Abstract

In order to evaluate the therapeutic advantages of various autologous platelet concentrates (APC) as a single biomaterial during alveolar ridge preservation (ARP), a systematic review with meta-analyses was conducted. PubMed, EMBASE, Web of Science, and Scopus were screened for randomized controlled trials (RCTs) that were released prior to 2024. The selected papers compared an APC with either unassisted healing (blood clot) or another biomaterial during ARP (third molars were not included). The outcome parameters included alveolar bone dimension alterations, soft tissue healing, and post-op pain intensity. The search yielded 35 papers (33 studies), one applying platelet-rich plasma (PRP), six using plasma rich in growth factors (PRGF), and 28 using leukocyte- and platelet-rich fibrin (L-PRF). These studies showed a large heterogeneity (e.g., outcome parameters, timing, surgical approach, and inclusion criteria), which hindered drawing strong conclusions. In most studies, however, ARP with PRP, PRGF, and L-PRF alone produced faster soft tissue healing, less post-extraction pain, less alveolar ridge resorption, more socket bone fill, and a higher bone density when compared to unassisted (spontaneous) healing. The ultimate benefit appears to be significantly influenced by the surgical approach. Limited literature exists comparing APC with other biomaterials for ARP, resulting in inconclusive data. APC application for ARP is a promising strategy to improve soft and hard tissue healing and reduce post-extraction pain.

Keywords: alveolar ridge preservation; autologous platelet concentrates; extraction socket; leukocyte‐ and platelet‐rich fibrin; plasma rich in growth factor; platelet rich fibrin; platelet rich plasma..

FIGURE 1

Flow chart of the search strategy.

FIGURE 2

Risk for bias assessment for each individual study considering five domains. D1: Randomization/allocation, allocation concealment, difference in baseline data caused by patient selection; D2: Blinding of participants, surgeons, and personnel; D3: Blinding towards outcome assessment/outcome assessors; D4: Incomplete outcome data; D5: Incomplete outcome data.

FIGURE 3

Overall risk of bias graph (authors' judgments) about each risk of bias item presented as percentages across all included studies.

FIGURE 4

Forest plots illustrating the impact of APC on alveolar ridge dimensional changes after tooth extraction compared to unassisted healing. (A) Horizontal width reduction 1 mm below the crest. (B) Horizontal width reduction 2–3 mm below the crest. (C) Reduction of the vertical height of the buccal bone. (D) Percentage of socket fill.

FIGURE 5

Clinical case of ARP with L‐PRF in the anterior zone. (A) Cross‐sectional CBCT image of tooth number 21, prior to extraction; (B) Extraction of tooth number 21 including the apical granuloma; (C): Application of L‐PRF membranes (2 membranes to fill and 1 double layer L‐PRF membrane to cover) inside the extraction socket of tooth number 21 and placing a positioning suture; (D) Cross‐sectional CBCT image after 3 months of healing; (E) Frontal view showing the soft tissue healing at the extraction site; (F) incisal view showing the osteotomy preparation for dental implant at site 21 (favorable horizontal and vertical ridge dimensions and good vascularization).

FIGURE 6

Clinical case of ARP with L‐PRF in the posterior zone. (A) The first premolar in the upper right side was extracted (loss of the entire buccal bone plate, PPD > 10 mm, endodontic pathology); (B) After 1 week, the soft tissue starts covering the top L‐PRF membrane, which is sealing the entrance to the socket; this membrane shows some pink spots (probably due to vascularization); (C) Good soft tissue healing after 3 months with minimal change in alveolar crest dimensions; (D) Cross‐sectional CBCT image in the center of the extraction socket showing optimal bone regeneration with moderate bone calcification; (E) Re‐entry after 3 months with the entire re‐generation of the buccal bone plate; (F) Insertion of a 3.6 mm diameter Astra‐Tech EV implant; (G) Intra‐oral radiograph after 7 years of loading.