Liang F, Wu M J, Zou L D
Second Clinical Division, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100101, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2021 Oct 18;53(5):970-976. doi: 10.19723/j.issn.1671-167X.2021.05.027.
To analyze the clinical curative effect after 5-year follow-up of single tooth implant-supported restorations in the posterior region.
In the study, patients with single tooth implant-supported restorations in the posterior region after loading 5-year in the Second Clinical Division of Peking University School and Hospital of Stomatology from October 2005 to May 2010 was enrolled. The implant survival rate, prosthetic conditions (including the structural integrity or loosening of the prosthesis, the retention of the materials used to fill access holes of screw-retained implant crowns, loosening or fractures of the implant abutment or screw) and marginal bone lever level around implants were determined by clinical and radiographic examination.
The study was composed of 215 patients, the mean age was 48.6 years (range: 27 to 71), and 321 soft tissue implants were inserted. There were 9 implants loose and lost during the visit, the cumulative success rate was 97.2%. In the 312 remaining implants, 120 implants were placed in the upper jaws (38.5%) and 192 in the lower jaws (61.5%). Three different diameters as 3.3 mm (5 implants), 4.1 mm (115 implants) and 4.8 mm (192 implants) and three different lengths as 8 mm (21 implants), 10 mm (206 implants) and 12 mm (85 implants) were used, respectively. 277 (88.8%) cement-retained and 35 (11.2%) screw-retained implant-supported single crowns were made. The marginal bone loss (MBL) around dental implants after loading 5 years in the mesial and distal sides were (0.73±0.25) mm and (0.78±0.26) mm, respectively. There was no significant difference among MBL and bone quality, implant type, angle of abutment, prosthodontic type, crown-to-implant ratio, gender, and age of the patients ( > 0.05). The major mechanical complications after restoration involved loosening (8.6%) and fracture (2.9%) of the crown retainer screw, loss of resin covering the screw (11.4%), and the most frequent mechanical complications were loss of crown retention (14.1%) and fracture of porcelain (13.8%). The incidence of loss of crown retention was correlated with insufficient clinical crown height or using angle abutment ( < 0.05).
After loading 5 years, the bone level around the soft-tissue-implant placed in posterior region was stable. To minimize the frequency of mechanical complications after restoration, protocols must be established from diagnosis to the completion of treatment and follow up of implant-supported prostheses, especially in terms of adequate technical steps and careful radiographic evaluation of the components.
分析后牙单颗种植修复5年随访后的临床疗效。
本研究纳入2005年10月至2010年5月在北京大学口腔医学院·口腔医院第二临床科室接受后牙单颗种植修复且已完成5年种植体加载的患者。通过临床和影像学检查确定种植体存留率、修复情况（包括修复体的结构完整性或松动情况、用于填充螺丝固位种植冠接入孔的材料的存留情况、种植体基台或螺丝的松动或折断情况）以及种植体周围的边缘骨水平。
本研究共纳入215例患者，平均年龄48.6岁（范围：27至7I岁），共植入321颗软组织种植体。随访期间有9颗种植体松动脱落，累计成功率为97.2%。在剩余的312颗种植体中，上颌植入120颗（38.5%），下颌植入192颗（61.5%）。分别使用了三种不同直径，即3.3mm（5颗种植体）、4.1mm（115颗种植体）和4.8mm（192颗种植体），以及三种不同长度，即8mm（21颗种植体）、10mm（206颗种植体）和12mm（85颗种植体）。制作了277颗（88.8%）粘结固位和35颗（11.2%）螺丝固位的种植支持单冠。种植体加载5年后，近中侧和远中侧种植体周围的边缘骨吸收（MBL）分别为（0.73±0.25）mm和（0.78±0.26）mm。MBL与骨质量、种植体类型、基台角度、修复类型、冠根比、患者性别和年龄之间无显著差异（P>0.05）。修复后的主要机械并发症包括冠固位螺丝松动（8.6%）和折断（2.9%）、覆盖螺丝的树脂缺失（11.4%），最常见的机械并发症是冠固位丧失（14.1%）和瓷折（13.8%）。冠固位丧失的发生率与临床冠高度不足或使用角度基台相关（P<0.05）。
加载5年后，后牙区软组织种植体周围的骨水平稳定。为了尽量减少修复后机械并发症的发生频率，必须从种植支持修复体的诊断、治疗完成到随访建立规范流程，尤其是在采取适当的技术步骤和对部件进行仔细的影像学评估方面。
