Eficácia da L-PRF isolada ou associada ao enxerto sintético HA/β-TCP no processo de reparo ósseo em alvéolos maxilares frescos: estudo histomorfométrico comparativo de curto prazo em humanos

Abstract

Tooth extraction results in changes in soft and hard tissues, which may affect implant placement. The use of platelet- and leukocyte-rich fibrin (L-PRF), alone or in combination with another biomaterial, has been adopted to facilitate bone repair and optimize bone graft adhesion. The objective of this randomized, prospective, blinded controlled clinical study was to verify, comparatively in humans, by histomorphometry, after an eight-week period, the efficacy of LPRF alone or in combination with biphasic calcium phosphate-based bioceramics containing hydroxyapatite and beta-tricalcium phosphate (HA/β-TCP), in the bone repair process in fresh maxillary alveoli. The sample consisted of sixty surgical beds of 15 volunteers of both sexes, aged between 41 and 69 years (mean 56.7  8.2 years), with indication for post-extraction grafting of single-root elements, for maintenance of the alveolar ridge and subsequent insertion of implants. The dental alveoli were randomized to one of four approaches: control (CTR), only extractions; autogenous bone (AB), particulate autogenous bone; L-PRF (LPRF), L-PRF membrane, and; L-PRF + HA/β-TCP (LPRFHA), L-PRF associated with synthetic graft. The surgical procedure was performed in two stages with an interval of eight weeks, the first for removal of the dental elements and grafting of the alveoli, and the second, after eight weeks (54-60 days; mean of 57.5  1.9 days) aimed at bone collections for histomorphometric analysis and insertion of implants. The histomorphometry of the bone repair area (BRA) was based on ten photomicrographs of each slide, which were analyzed quantitatively in the ImageJ software. The analysis of variance method (one-way ANOVA) with F tests was applied, followed by multiple comparisons with Bonferroni post-hoc, all established at p  0.05. When comparing the BRA (%) measurements, there was a statistical difference (p = 0.014) in the pair (CTR  LPRFHA). In the multiple comparisons, it was observed that the control group (CTR) exhibited the highest mean rate (62.4  18.6%) in relation to LPRFHA with the lowest mean rate (55.8  17.2%), significant at p = 0.012. The groups of interest LPRF and LPRFAH did not present statistically significant differences. In the comparison between the LPRF and AB (gold standard) groups, both presented the same average rates (60.2  17.5% and 60.1  20.0%, respectively). Thus, it can be concluded that, in humans, both L-PRF alone and associated with the HA/β-TCP synthetic graft was effective, in the short term, in the bone repair process; however, L-PRF alone presented the same percentage of bone formation as the AB. When associated with the HA/β-TCP synthetic graft, L-PRF demonstrated a tendency to reduce the bone repair process. Thus, this study validates the isolated use of L-PRF in humans, as a biomaterial for the formation of vital bone in maxillary alveoli after tooth extraction, enhancing bone repair in the eight-week period.