Int J Oral Maxillofac Implants. 2022 Jul-Aug;37(4):784-792. doi: 10.11607/jomi.8924.
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.
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.
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.
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.
即刻种植体的出现彻底改变了种植体领域,与传统种植体相比具有显著优势。在拔牙窝中缺乏足够的骨量引发了关于种植体即刻负重的合适时机的问题。血小板浓缩物已被广泛用于加速颌面区域的骨再生。本研究评估了血小板浓缩物对上颌和下颌磨牙区骨愈合和种植体稳定性的影响。骨再生受多种生长因子调节,特别是血管内皮生长因子(VEGF)和转化生长因子-β1(TGF-β1);因此,本研究评估了血小板浓缩物中这些因子的定量及其与骨愈合的相关性。
本随机临床试验的主要目的是比较富含血小板纤维蛋白(PRF)和浓缩生长因子(CGF)处理的上颌和下颌磨牙区即刻种植体稳定性,使用共振频率分析(RFA)。次要目标是评估使用 PRF 和 CGF 进行的种植体周围骨再生,并定量分析制备的 CGF 和 PRF 中的生长因子 VEGF 和 TGF-β1 及其与骨愈合的相关性(如果有)。共有 36 名患者随机分为三组(每组 12 名):对照组、PRF 组和 CGF 组。所有患者均即刻植入种植体,或使用或不使用血小板浓缩物(PRF 或 CGF)。术后即刻、4 周、8 周和 12 或 16 周(下颌 12 周,上颌 16 周)时使用 RFA 测量种植体稳定性。术后即刻和 8 周及 12 或 16 周时,通过口腔根尖射线照相术测量放射密度和骨间隙(水平/垂直)。
在比较种植体稳定性指数(ISQ)、放射密度/灰度(GS)和水平及垂直骨间隙(HG 和 VG)时,在任何时间点,三组之间均无显著差异。在 8 周的 ISQ 分析中,对照组有显著改善(P =.04),而在 12 或 16 周时,PRF 组(P =.03)和 CGF 组(P =.02)有显著改善。在 GS 评估中,只有对照组在 12 或 16 周时显示出显著改善(P =.009)。在水平和垂直骨间隙分析中,三组在 8 周时均显示出显著改善(对照组[P <.001],PRF 组[P =.001],CGF 组[P =.01])和 12 或 16 周时(对照组[P <.001],PRF 组[P <.001],CGF 组[P =.006])。酶联免疫吸附试验(ELISA)定量分析 VEGF 和 TGF-β1 显示 PRF 中的 VEGF 浓度明显高于血浆,而 TGF-β1 的浓度在两组中相似。
血小板浓缩物的应用似乎可以增强种植体的稳定性,但在所有时间点,组间结果均无统计学意义。在比较骨再生的质量(放射密度/灰度)和数量(水平和垂直骨间隙减少)时,三组之间没有统计学上的显著差异。需要更大样本量的研究来对血小板浓缩物在牙科种植体中的疗效做出明确的结论。