Department of Dental Clinical Specialties, Faculty of Dentistry, Complutense University, Madrid, Spain.
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Sao Paulo, Brazil.
Clin Implant Dent Relat Res. 2019 Oct;21(5):1087-1098. doi: 10.1111/cid.12834. Epub 2019 Aug 16.
A main drawback of bone block graft surgery is the resorption occurring in early stages of healing. To our knowledge, there are no studies comparing outcomes of freeze-dried bone allograft (FDBA) blocks with different architecture.
The aim of this work was to investigate different factors that can affect graft resorption and to compare the resorption rates of two different types of allogeneic blocks, corticocancellous and cancellous.
A randomized clinical trial was designed. Twenty-eight patients referred for onlay bone augmentation prior to implant placement were included in the study. Preoperative computerized tomography (CT) was taken for all patients. Patients received FDBA blocks of either cancellous or corticocancellous bone obtained from the iliac crest. After a 4-month follow-up, postoperative CT was taken. Then, another surgery was performed, with the purpose to place dental implants. The aforementioned groups were compared for bone resorption and implant outcome using analysis of covariance (ANCOVA) and repeated ANOVA measures, respectively. Demographic data, trabecular bone density, and graft sites were also analyzed.
A total of 93 implants were placed in the augmented bone sites over 28 patients. A 100% survival rate was achieved during a mean follow-up period of 24 months in both groups. Higher bone resorption rate was found with cancellous bone grafts (29.2% ± 2.6) compared with corticocancellous grafts (19.3% ± 2.3). Moreover, higher resorption rates in patients with lower bone density (<185 Hounsfield Units) (31.7% ± 3.1) and smokers (26.39% ± 2.3) were observed when compared with patients with higher bone density (>185 Hounsfield Units) (16.8% ± 2.1) and nonsmokers (22.1% ± 2.3), respectively.
Within the limitations of this study, these findings indicate that both corticocancellous and cancellous FDBA grafts constitute a clinical acceptable alternative for bone reconstruction, although cancellous grafts present higher resorption rates. Moreover, host factors such as patient's low bone density and smoking habits may also increase graft resorption rates.
骨块移植手术的一个主要缺点是在愈合的早期会发生吸收。据我们所知，目前还没有研究比较不同结构的冻干骨同种异体移植物（FDBA）块的结果。
本研究旨在探讨影响移植物吸收的不同因素，并比较两种不同类型同种异体移植物（皮质松质和松质）的吸收率。
设计了一项随机临床试验。将 28 名因种植体放置前骨层状增加而就诊的患者纳入研究。所有患者均进行术前计算机断层扫描（CT）。患者接受来自髂嵴的皮质松质或松质 FDBA 块。4 个月后进行术后 CT。然后进行另一次手术，目的是放置牙种植体。使用协方差分析（ANCOVA）和重复方差分析分别比较上述各组的骨吸收和种植体结果。还分析了人口统计学数据、骨小梁密度和移植物部位。
在 28 名患者中，共有 93 个种植体被放置在增强的骨部位。两组的平均随访期均为 24 个月，均达到 100%的存活率。与皮质松质移植物（29.2%±2.6）相比，松质骨移植物的吸收率更高（29.2%±2.6）。此外，与骨密度较高的患者（>185 亨氏单位）（16.8%±2.1）和非吸烟者（22.1%±2.3）相比，骨密度较低（<185 亨氏单位）的患者（31.7%±3.1）和吸烟者（26.39%±2.3）的吸收率更高。
在本研究的限制范围内，这些发现表明皮质松质和松质 FDBA 移植物均可作为骨重建的临床可接受替代物，尽管松质移植物的吸收率更高。此外，患者的低骨密度和吸烟习惯等宿主因素也可能增加移植物的吸收率。
