前牙美学区引导骨再生同期种植愈合期间边缘骨吸收的前瞻性研究

目的：研究前牙美学区引导骨再生（guided bone regeneration,GBR）同期种植愈合期间的边缘骨吸收情况。方法：纳入2015年9月—2016年4月在上海交通大学医学院附属第九人民医院口腔种植科需要行ＧＢＲ同期种植体植入患者。手术当天及二期手术阶段均拍摄平行投照根尖片及口腔颌面部锥形束CT,记录牙龈厚度（>2 mm或≤2 mm）、骨质分类及使用的膜的类型。手术当天根尖片近、远中边缘骨水平分别记为MB1及DB1,二期手术阶段分别记为MA1及DA1,2次差值记为MD1及DD1。手术当天及二期手术阶段CBCT对种植体近中及远中的测量值分别记为MB2、DB2、MA2及DA2,测量结果之差记为MD2及DD2;唇、腭侧骨吸收差值分别记为BD和LD。采用SPSS 21.0软件包对数据进行统计学分析。结果：纳入30例GBR同期种植体植入位点。根尖片上,近、远中骨吸收分别为（1.61±1.03）mm和（1.39±0.91）mm。CBCT上观察到近、远中,唇、腭侧骨吸收中位数（四分位间距）分别为1.34 mm（0.00~2.25 mm）、0.90 mm（0.00~2.00 mm）、0.71 mm（0.00~1.41 mm）和0.47 mm（0.00~1.49 mm）。根尖片与CBCT比较得出MB1/MB2和DB1/DB2的数值无显著相关性（P>0.05）,而MA1/MA2 和DA1/DA2呈中等程度相关（P<0.01）。MD1中,将不同牙龈厚度、骨质亚类及膜的类型进行比较,结果分别为P=0.86、0.02和0.83。DD1中,结果均无显著差异（P=0.74、0.40和0.40）。结论：前牙美学区GBR同期种植愈合期间存在一定程度的边缘骨吸收。CBCT对种植体边缘骨的测量不一定准确。不同牙槽骨骨质类型可能对边缘骨吸收有影响。     

Two alternative surgical techniques for enhancing primary implant stability in the posterior maxilla: a clinical study including bone density, insertion torque, and resonance frequency analysis data

Background: The primary stability of dental implants associated with resistance to micromotion during healing is affected by surgical technique and implant design, which are important especially in the soft bone, where implant failures are more likely. Purposes: This study was designed to compare the parameters associated with implant insertion using two different methods of enhancing implant primary stability and to identify any relationship between these parameters at implant insertion. Materials and Methods: A total of 60 implants were placed in the maxillary posterior regions of 22 patients. The bone densities at the implant sites were recorded using a computerized tomography machine in Hounsfield unit (HU). The maximum insertion torque data were recorded with the Osseocare™ (Nobel Biocare AB, Göteborg, Sweden) equipment, while resonance frequency analysis (RFA) measurements were taken using an Osstell™ (Integration Diagnostics AB, Göteborg, Sweden) machine at implant surgery. Comparisons including HU, Ncm, and implant stability quotient were made between two control groups (C1 and C2), and corresponding four test groups (T1–T4) using thinner drills to enhance primary implant stability. Results: Two implants were lost, meaning an overall implant survival rate of 96.6% after 3 ± 1 years. When compared to control groups, significantly higher mean maximum insertion torque and RFA values were found for corresponding test groups. In addition, strong correlations were observed between the bone density and insertion torque, and implant stability values at implant placement. Conclusion: The results of this study suggest that using thinner drills for implant placement in the maxillary posterior region where bone quality is poor may improve the primary implant stability, which helps clinicians to obtain higher implant survival rates.