Schropp Lars, Wenzel Ann, Spin-Neto Rubens, Stavropoulos Andreas
Prosthetic Dentistry, Department of Dentistry, Aarhus University, Aarhus C, Denmark; Oral Radiology, Department of Dentistry, Aarhus University, Aarhus C, Denmark.
Clin Oral Implants Res. 2015 May;26(5):492-500. doi: 10.1111/clr.12424. Epub 2014 Jun 2.
To present 10-year cone beam CT (CBCT) data on the fate of buccal bone at single-tooth implants placed early, delayed, or late after tooth extraction.
Sixty-three of 72 patients, originally randomly allocated to three equal-size groups, received a single-tooth implant on average 10 days (Ea; N = 22), 3 months (De; N = 22), or 1.5 years (La; N = 19) after tooth extraction. Healing abutments were mounted after a 3-month period of submerged healing and metalceramic crowns were cemented after one additional month. At the second stage surgery, presence of buccal bone defects (dehiscences or intrabony) and their dimensions were registered. CBCT scans recorded with a Scanora(®) 3D unit and standardized periapical (PA) radiographs of the implants were obtained at the 10-year control. Interproximal bone levels (i.e., the distance from the implant platform to the first bone-to-implant contact; BIC) measured in CBCT image sections and PA were compared, and the buccal bone level was determined in the CBCT images.
Two Ea and one De implants failed to osseointegrate. Forty-nine patients attended the 10-year control and due to poor quality of 5 CBCT scans, useful CBCT images were available from 44 patients (Ea:12, De:17, La:15). No significant differences between CBCT and PA images in measurements of the interproximal bone levels were observed. Ten years after implant placement, BIC at the buccal aspect was located on average 2 mm apically to the implant platform (2.39 ± 1.06 mm [median = 2.36] for Ea, 2.22 ± 0.99 mm [median = 2.16] for De, and 1.85 ± 0.65 mm [median = 1.95] for La implants) with no significant difference among the groups (P = 0.20). Mean buccal bone level (bBL) for implants with an intrabony or a dehiscence defect at second stage surgery was 2.51 ± 1.12 mm [median = 2.70] and 2.84 ± 0.70 mm [median = 2.79], respectively, while 1.78 ± 0.74 mm [median = 1.93] for the implants with no defect. The difference in bBL between the implants without a defect and those with a dehiscence was significant at 10 years (P = 0.0005).
Time of placement of single-tooth implants after tooth extraction did not significantly influence the peri-implant buccal bone level, while presence of a buccal bone dehiscence at second stage surgery resulted in significantly more apically located BIC buccally at 10 years.
呈现10年锥形束CT（CBCT）数据，以了解拔牙后早期、延迟或晚期植入单颗牙种植体时颊侧骨的转归情况。
72例患者最初被随机分为3个等规模组，其中63例患者在拔牙后平均10天（早期组，Ea；n = 22）、3个月（延迟组，De；n = 22）或1.5年（晚期组，La；n = 19）接受了单颗牙种植体植入。在3个月的潜行愈合期后安装愈合基台，并在再过1个月后粘结金属烤瓷冠。在二期手术时，记录颊侧骨缺损（骨开裂或骨内缺损）的存在情况及其尺寸。在10年随访时，使用Scanora(®) 3D设备进行CBCT扫描，并获取种植体的标准化根尖片（PA）。比较在CBCT图像切片和PA中测量的邻间骨水平（即从种植体平台到首次骨与种植体接触点的距离；骨结合，BIC），并在CBCT图像中确定颊侧骨水平。
2颗早期组种植体和1颗延迟组种植体未实现骨整合。49例患者参加了10年随访，由于5例CBCT扫描质量不佳，44例患者（早期组：12例，延迟组：17例，晚期组：15例）获得了可用的CBCT图像。在邻间骨水平测量中，未观察到CBCT和PA图像之间存在显著差异。种植体植入10年后，颊侧的骨结合平均位于种植体平台根尖方向2 mm处（早期组种植体为2.39±1.06 mm [中位数 = 2.36]，延迟组种植体为2.22±0.99 mm [中位数 = 2.16]，晚期组种植体为1.85±0.65 mm [中位数 = 1.95]），组间差异无统计学意义（P = 0.20）。二期手术时有骨内或骨开裂缺损的种植体的平均颊侧骨水平（bBL）分别为2.51±1.12 mm [中位数 = 2.70]和2.84±0.70 mm [中位数 = 2.79]，而无缺损的种植体为1.78±0.74 mm [中位数 = 1.93]。无缺损种植体与有骨开裂缺损种植体的颊侧骨水平差异在10年时具有统计学意义（P = 0.0005）。
拔牙后单颗牙种植体的植入时间对种植体周围颊侧骨水平无显著影响，而二期手术时存在颊侧骨开裂会导致10年后颊侧骨结合在根尖方向显著更低。
