Morris H F, Ochi S
Dental Implant Clinical Research Group, VA Medical Center, Ann Arbor, MI, USA.
Ann Periodontol. 2000 Dec;5(1):15-21. doi: 10.1902/annals.2000.5.1.15.
Numerous new implant designs and materials have become available over the last decade, each with special claims of superiority in restoring complex cases. Differences in existing clinical databases, study designs, and methods of determining failures/survival are seldom standardized, which complicates comparisons of clinical performance of these new designs. Little information is available concerning the changes in stability of various designs and materials following clinical loading.
A total of 30 VA medical centers and 2 dental schools combined to form the Dental Implant Clinical Research Group (DICRG). More than 2,900 implants were placed, restored and data gathered from the time of placement to 36 months. Implant stability from uncovering to 36 months and survival from placement to 36 months were determined. Survival was determined using two different approaches--considering all implants removed at any time, regardless of the reason (DICRG approach), and considering only those that were removed following loading of the prosthesis (post-loading approach). Survival was also determined for each of the three phases of implant treatment--phase 1, from the time of placement to uncovering and abutment connection; phase 2, from uncovering to placement and loading of the prosthesis; and phase 3, from loading of the prosthesis to 36 months.
The two approaches to determining survival for each implant design and/or material included in the study showed differences in reported numbers ranging from 1.1% to 21.7%. The largest difference in survival was for the commercially pure titanium screw (used in this study only in the maxillary completely edentulous applications), which showed a 21.7% greater survival rate. With the DICRG approach, the hydroxyapatite (HA)-cylinder had the highest survival (97.5%). When considering the post-loading approach, the titanium-alloy screw had the highest survival (99.4%), with the HA-cylinder having the next highest survival (98.6%). The HA-cylinder did not show increased stability from uncovering to 36 months, and the HA-grooved implant became less stable.
HA-coated implants demonstrated the highest survival rate; 2) the post-loading analysis approach inflated survival; 3) non-HA implants showed increased stability following loading; 4) HA-coated implants showed a slight decrease or no change in stability; and 5) the clinical significance of the changes in implant stability must be determined for the long-term.
在过去十年中，出现了许多新的种植体设计和材料，每种都宣称在修复复杂病例方面具有独特的优势。现有临床数据库、研究设计以及确定失败/存活的方法很少标准化，这使得比较这些新设计的临床性能变得复杂。关于各种设计和材料在临床加载后稳定性变化的信息很少。
30个退伍军人医疗中心和2所牙科学院联合组成了牙种植体临床研究组（DICRG）。植入了2900多个种植体，进行修复，并收集了从植入到36个月的数据。确定了从暴露到36个月的种植体稳定性以及从植入到36个月的存活率。存活率采用两种不同方法确定——考虑任何时间取出的所有种植体，无论原因如何（DICRG方法），以及仅考虑在假体加载后取出的种植体（加载后方法）。还确定了种植体治疗三个阶段中每个阶段的存活率——第1阶段，从植入到暴露和基台连接；第2阶段，从暴露到假体植入和加载；第3阶段，从假体加载到36个月。
研究中每种种植体设计和/或材料确定存活率的两种方法显示报告数字的差异在1.1%至21.7%之间。存活率差异最大的是商业纯钛螺钉（本研究仅用于上颌全口无牙应用），其存活率高出21.7%。采用DICRG方法时，羟基磷灰石（HA）圆柱状种植体存活率最高（97.5%）。考虑加载后方法时，钛合金螺钉存活率最高（99.4%），HA圆柱状种植体其次（98.6%）。HA圆柱状种植体从暴露到36个月未显示稳定性增加，HA带槽种植体变得不太稳定。
1）HA涂层种植体显示出最高的存活率；2）加载后分析方法提高了存活率；3）非HA种植体在加载后稳定性增加；4）HA涂层种植体稳定性略有下降或无变化；5）种植体稳定性变化的临床意义必须从长期角度确定。
