引导骨再生术在种植手术中的应用

<正>1982年,Nyman用一种半透性滤膜治疗牙周病,后扩展应用于骨缺损的治疗。1993年,Buser等提出了引导骨再生(guided boneregeneration,GBR)的概念。其原理是根据各类组织细胞迁移速度不同,将屏障膜置于软组织和骨缺损之间建立生物屏障,创造一个相对封闭的组织环境,阻止结缔组织细胞和上皮细胞进入骨缺损区,允许有潜在生长能力、迁     

钛膜和胶原膜联合应用引导种植体周骨缺损骨再生的临床研究

目的：评价钛膜与胶原膜联合应用引导种植体骨缺损骨再生的临床效果。方法：将34颗种植体植入30例患者的狭窄形牙槽嵴或唇颊骨壁缺损拔牙窝,所有种植体的唇、颊侧面部分暴露,种植体周骨缺损空间维持能力较差。测量种植暴露部分的最大长度,将羟基磷灰石珊瑚骨粉置于骨缺损处,采用钛膜覆盖稳定骨移植材料,然后将胶原膜覆盖于钛膜表面,无张力缝合伤口,术后6个月行Ⅱ期手术,取下钛膜,检查骨缺损骨再生的状况,再次测量种植暴露部分的最大长度。结果：2例患者于手术3个月左右因钛膜局部暴露,将钛膜取出。钛膜暴露率为6.6%。术后6个月Ⅱ期手术时见,所有种植体暴露部分完全被再生骨覆盖,种植体暴露部分长度为0。结论：在空间维持能力较差的骨缺损处,钛膜和胶原膜联合应用引导骨再生可获得理想结果。钛膜和胶原膜联合应用可显著降低钛膜的暴露率,延迟发生膜暴露的时间,从而使引导骨再生的结果更加具有可预测性。     

Platelet‐Rich Plasma–Assisted Guided Bone Regeneration for Ridge Augmentation: A Randomized,Controlled Clinical Trial

Background: Platelet‐rich plasma (PRP) contains a number of biologically active growth factors, and previous studies have reported conflicting ridge augmentation results. The primary aim of this randomized, controlled, masked, clinical trial was to determine if PRP combined with a rapidly resorbing cancellous allograft would enhance the regenerative result compared with an allograft without PRP. Methods: Thirty‐two patients with an edentulous ridge defect were sequentially entered into the study; four were excluded from data analysis. Fourteen patients received a cancellous allograft (CAN group) and the other 14 received a cancellous allograft mixed with PRP (PRP group). All 28 grafted sites were covered with a resorbable polylactide membrane. After elevation of a full‐thickness flap, horizontal ridge dimensions were measured with a digital caliper at the crest and 5 mm apical to the crest. Vertical ridge dimensions were measured from a tooth‐supported stent. All sites were reentered at 4 months, and a trephine core was obtained for histologic analysis before implant placement. Results: The crestal ridge width for the CAN group had a mean gain of 2.0 ± 1.2 mm, whereas the PRP group gained 2.9 ± 1.0, and the difference was statistically significant between groups (P <0.05). The percent vital bone was 36% ± 14% for the CAN group compared with 51% ± 15% for the PRP group and was statistically significant between groups (P <0.05). Loss of augmented ridge width was 34% ± 17% for the CAN group and 28% ± 17% for the PRP group (P >0.05). Conclusion: These clinical and histologic findings suggest that PRP enhanced bone regeneration and resulted in increased horizontal bone gain and percentage vital bone.     

Use of a Collagen Membrane Loaded With Recombinant Human Bone Morphogenetic Protein‐2 With Collagen‐Binding Domain for Vertical Guided Bone Regeneration

Background: Vertical bone regeneration of severe atrophic alveolar ridges remains a challenging procedure in implant dentistry. Methods: The aim of this study, accordingly, is to use a rabbit vertical guided bone regeneration model to evaluate whether using a collagen membrane (CM) loaded with small doses of recombinant human bone morphogenetic protein‐2 with collagen‐binding domain (rhBMP‐2/CBD) would enhance two‐way vertical bone regeneration. In each of eight rabbits, four titanium cylinders were screwed in perforated slits made into the external cortical bones of the calvaria. The following four treatment modalities were randomly allocated: 1) cylinders filled with mineralized bone matrix and covered with CM/rhBMP‐2/CBD; 2) cylinders filled with mineralized bone matrix and covered with CM/rhBMP‐2; 3) cylinders filled with mineralized bone matrix and covered with CM alone; or 4) cylinders filled with mineralized bone matrix without a membrane cover. Results: After 6 weeks, the new bones were examined by histologic analysis. Slender new bone trabeculae were observed in the superficial layer of the titanium cylinders covered with CM/rhBMP‐2/CBD, and higher degrees of bone were observed in this group compared with the other three groups. The average area fraction of newly formed bone was significantly more in the CM/rhBMP‐2/CBD group compared with the CM/rhBMP‐2, CM, or the no membrane control groups (all P <0.01). Conclusions: The present study demonstrates that CMs loaded with small doses of rhBMP‐2/CBD induce new bone formation not only from the surface of the native bone, but also from the superficial structures. The augmented new bone, therefore, is improved in both quantity and quality.     

Retrospective analysis of time-related three-dimensional iliac bone graft resorption following sinus lift and vertical augmentation in the maxilla

The atrophic maxilla frequently requires bone grafting using an onlay graft (OG) or sinus lifting (SL) before implant rehabilitation. The resorption of bone grafts is influenced by the time until implantation, quality of donor bone, and grafting technique. The aim of this study was to investigate the impact of both grafting techniques on the time-related resorption of autologous iliac bone graft. Forty-three patients underwent either onlay grafting or a sinus lift at 73 sites in the maxilla. Graft height was measured by cone beam computed tomography after augmentation and during follow-up for up to 12 months prior to implant insertion. The effect of time and technique on graft resorption was evaluated retrospectively. The reduction in bone graft height was greater for OG than SL over the investigated time intervals (OG = 51%, SL = 28%; P = 0.002). Each technique followed a specific course of resorption, which was independent of the initial graft height and could be calculated by a non-linear regression model. Iliac bone graft undergoes rapid resorption when used as an OG prior to implant insertion. For SL, this resorption is reasonably lower. This is especially crucial to determine the optimal time for implant insertion after graft healing to improve implant survival.