目的: 分析后牙区单牙种植修复患者在行使功能5年后的临床修复疗效。方法: 选取2005年10月至2010年5月在北京大学口腔医院第二门诊部接受种植治疗并且负重已达到5年的后牙区种植治疗患者,回顾患者的临床资料、X线片、种植体近远中边缘骨高度的变化以及修复体的情况(包括修复体完整性、松动情况、螺丝孔封闭材料存留状况、修复体固位螺丝及修复基台的松动或折断情况)来评估临床疗效。结果: 215例患者,平均年龄48.6岁(27~71岁),共植入软组织水平种植体321枚(其中上颌126枚、下颌195枚)。9枚种植体在回访期间出现松动、脱落,累计存留率达97.2%。存留的312枚种植体中,上颌120枚、下颌192枚,其中直径为3.3、4.1和4.8 mm的种植体分别为5枚(1.6%)、115枚(36.9%)和192枚(61.5%),长度为8、10和12 mm的种植体分别为21枚(6.7%)、206枚(66.0%)和85枚(27.2%)。上部修复体固位方式中,粘接固位为277枚(88.8%),螺丝固位为35枚(11.2%)。负载5年后种植体近远中牙槽骨高度平均吸收分别为(0.73±0.25) mm和(0.78±0.26) mm,近远中骨吸收程度与植入区骨质类型、种植体规格、修复基台角度、固位方式、临床冠-种植体长度比、性别、年龄等因素均未显示有相关性(P>0.05)。修复后主要的机械并发症有:修复体固位螺丝松动(8.6%)或折断(2.9%)、修复体上螺丝孔封闭材料脱落(11.4%)、修复体崩瓷(13.8%)及修复体脱粘(14.1%),其中仅修复体脱粘的发生率与修复时使用的基台角度(0°/15°)和修复体的临床高度这两个因素相关(P<0.05)。结论: 软组织水平种植体在单颗后牙缺失的修复病例中负重5年后,种植体周围的骨水平基本稳定,全面完善的种植诊疗计划、规范严谨的临床操作以及定期的复查可能是减少修复后并发症的有效方法。

Objective: To analyze the clinical curative effect after 5-year follow-up of single tooth implant-supported restorations in the posterior region. Methods: 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. Results: 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 (P>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 (P<0.05). Conclusion: 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.