Schropp Lars, Kostopoulos Lambros, Wenzel Ann
Department of Oral Radiology, University of Aarhus, Arhus, Denmark.
Int J Oral Maxillofac Implants. 2003 Mar-Apr;18(2):189-99.
The aim of this study was to compare bone healing and crestal bone changes following immediate (Im) versus delayed (De) placement of titanium dental implants with acid-etched surfaces (Osseotite) in extraction sockets.
Forty-six patients were randomly allocated to the Im or De group (n = 23 per group) and received 1 implant at the incisor, canine, or premolar region of the maxilla or the mandible. The implants were placed an average of 10 days following tooth extraction in the Im group and approximately 3 months after extraction in the De group. The widths (parallel and perpendicular to the implant) and the depth of marginal bone defects around the implants were measured clinically just after placement and 3 months later at the abutment surgery. The crestal bone changes mesially and distally to the implants were evaluated radiographically by linear measurements.
The survival rates were 91% in the Im group and 96% in the De group. In the Im group, the mean reductions in parallel width, perpendicular width, and depth of the largest defect of each implant amounted to 48% (from 4.4 to 2.3 mm), 59% (from 2.2 to 0.9 mm), and 48% (from 6.9 to 3.6 mm), respectively. The corresponding mean reductions in the De group amounted to 39% (from 3.1 to 1.9 mm), 77% (from 1.3 to 0.3 mm), and 34% (from 4.4 to 2.9 mm). The reduction over time was statistically significant in both groups (P < .04). For both groups, a higher degree of bone healing was achieved in the infrabony defects (> 60% for depth) than in dehiscence-type defects (approximately 25%). Furthermore, 70% of the 3-wall infrabony defects with a parallel width of up to 5 mm, a depth of maximum 4 mm, and a perpendicular width of maximum 2 mm had a capacity of spontaneous healing within a period of 3 months.
New bone formation occurs in infrabony defects associated with immediately placed implants in extraction sockets.
本研究旨在比较在拔牙窝中即刻（Im）与延迟（De）植入酸蚀表面（Osseotite）钛牙种植体后的骨愈合情况及牙槽嵴骨变化。
46例患者被随机分为Im组或De组（每组n = 23），在上颌或下颌的切牙、尖牙或前磨牙区植入1枚种植体。Im组在拔牙后平均10天植入种植体，De组在拔牙后约3个月植入。在种植体植入后及3个月后的基台手术时，临床测量种植体周围边缘骨缺损的宽度（平行和垂直于种植体）及深度。通过线性测量在影像学上评估种植体近中和远中牙槽嵴骨的变化。
Im组的生存率为91%，De组为96%。在Im组，每个种植体最大缺损的平行宽度、垂直宽度及深度的平均减少量分别为48%（从4.4 mm降至2.3 mm）、59%（从2.2 mm降至0.9 mm）和48%（从6.9 mm降至3.6 mm）。De组相应的平均减少量分别为39%（从3.1 mm降至1.9 mm）、77%（从1.3 mm降至0.3 mm）和34%（从4.4 mm降至2.9 mm）。两组随时间的减少均具有统计学意义（P < .04）。对于两组，骨下袋缺损（深度> 60%）的骨愈合程度高于裂开型缺损（约25%）。此外，平行宽度最大为5 mm、深度最大为4 mm、垂直宽度最大为2 mm的三壁骨下袋缺损中，70%在3个月内有自发愈合的能力。
在拔牙窝中即刻植入种植体相关的骨下袋缺损中会发生新骨形成。
