Purpose: Immediate dental implants revolutionized the field of implant dentistry with significant advantages over conventional implants. The lack of adequate bone in the extraction socket raises the question of the appropriate timing of implant loading. Platelet concentrates have been used widely to accelerate bone regeneration in the maxillofacial region. This study evaluates the effect of platelet concentrates on bone healing and implant stability in the maxillary and mandibular molar regions. Bone regeneration is regulated by several growth factors, particularly vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1); therefore, quantification of these factors in platelet concentrates and its correlation with bone healing has been assessed in this study.
Schlagwörter: concentrated growth factors, dental implant, immediate implant, implant stability quotient, osseointegration, platelet-rich fibrin
Materials and methods: The primary aim of this randomized clinical trial was to compare the stability of immediate dental implants in the maxillary and mandibular molar regions treated with platelet-rich fibrin (PRF) versus concentrated growth factors (CGF) using resonance frequency analysis (RFA). The secondary objectives were to evaluate the bone regenerate around implants with the use of PRF and CGF and to quantify growth factors VEGF and TGF-β1 in the prepared CGF and PRF and their correlation with bone healing, if any. A total of 36 patients were randomized into three groups (12 each): control, PRF, and CGF. In all patients, immediate implants were placed either with or without platelet concentrate (PRF or CGF). Implant stability was measured using RFA immediately postoperatively and at 4, 8, and 12 or 16 weeks (12 weeks for mandible and 16 weeks for maxilla) postoperatively. Radiodensity and the bone gap (horizontal/vertical) were measured on intraoral periapical radiographs immediately postoperatively and at 8 weeks and 12 or 16 weeks postoperatively.
Results: On comparing the implant stability quotient (ISQ), radiodensity/grayscale (GS), and horizontal and vertical bone gap (HG and VG), there was no significant difference noted between the three groups at any point in time. On ISQ analysis at 8 weeks, the control group showed a significant improvement (P = .04), whereas at 12 or 16 weeks, significant improvement was seen in PRF (P = .03) and CGF groups (P = .02). In GS assessment, only the control group showed significant improvement at 12 or 16 weeks (P = .009). In horizontal and vertical bone gap analysis all three groups showed significant improvement at 8 weeks (control [P < .001], PRF [P = .001], CGF [P = .01]) as well as 12 or 16 weeks (control [P < .001], PRF [P < .001], CGF [P = .006]). The enzyme-linked immunosorbent assay (ELISA) quantification of VEGF and TGF-β1 showed significant concentration of VEGF in PRF as compared to the plasma, while concentration of TGF-β1 was found to be comparable in both groups.
Conclusion: The application of platelet concentrates seems to enhance stability of implants, but intergroup results were nonsignificant at all time points. There was no statistically significant difference between the three groups when comparing quality (radiodensity/grayscale) and quantity (horizontal and vertical gap reduction) of bone regenerate. Studies with larger sample sizes are required to make conclusive assertions regarding efficacy of platelet concentrates in dental implants.