Duncan Warwick J, Ma Sunyoung, Siddiqi Allauddin, Osman Reham B
Faculty of Dentistry, University of Otago, P.O. Box 56, Dunedin 9016, New Zealand.
Specialist Private Practice, Brisbane, QLD 4122, Australia.
Materials (Basel). 2022 Aug 2;15(15):5322. doi: 10.3390/ma15155322.
Zirconia ceramic (ZC) implants are becoming more common, but comparisons between preclinical histology and long-term clinical trials are rare. This investigation comprised (1) 8-year clinical follow-up of one-piece ZC or titanium (Ti) implants supporting full overdentures and (2) histomorphometric analysis of the same implants in an animal model, comparing implants with various surface treatments.
(1) Clinical trial: 24 completely edentulous participants (2 groups of N = 12) received 7 implants (one-piece ball-abutment ZC or Ti; maxilla N = 4, mandible N = 3) restored with implant overdentures. Outcomes after 8-years included survival, peri-implant bone levels, soft-tissue responses, and prosthodontic issues. (2) Preclinical trial: 10 New Zealand sheep received 4 implants bilaterally in the femoral condyle: Southern Implants ZC or Ti one-piece implants, identical to the clinical trial, and controls: Southern ITC two-piece implants with the same surface or Nobel (NBC) anodised (TiUnite™) surface. %Bone-implant contact (%BIC) was measured after 12 weeks of unloaded healing.
8 of 24 participants (33%) of an average age of 75 ± 8 years were recalled; 21% of original participants had died, and 46% could not be contacted. 80.4% of implants survived; excluding palatal sites, 87.5% of Ti and 79% of ZC implants survived. All failed implants were in the maxilla. Three ZC implants had fractured. Bone loss was similar for Ti vs. ZC; pocket depths ( = 0.04) and attachment levels ( = 0.02) were greater for Ti than ZC implants. (1.7 ± 1.6 mm vs. 1.6 ± 1.3 mm). All implants in sheep femurs survived. %BIC was not statistically different for one-piece blasted surface Ti (80 ± 19%) versus ZC (76 ± 20%) or ITC (75 ± 16 mm); NBC had significantly higher %BIC than ITC (84 ± 17%, = 0.4).
Short-term preclinical results for ZC and Ti one-piece implants showed excellent bone-implant contact in unloaded femoral sites. This differed from the long-term clinical results in older-aged, edentulous participants. While ZC and Ti implants showed equivalent performance, the risks of peri-implantitis and implant loss in older, completely edentulous patients remain a significant factor.
氧化锆陶瓷（ZC）种植体正变得越来越普遍，但临床前组织学与长期临床试验之间的比较却很少见。本研究包括：（1）对支持全口覆盖义齿的一体式ZC或钛（Ti）种植体进行8年临床随访；（2）在动物模型中对相同种植体进行组织形态计量分析，比较不同表面处理的种植体。
（1）临床试验：24名全口无牙患者（两组，每组N = 12）接受7颗种植体（一体式球帽连接的ZC或Ti种植体；上颌N = 4，下颌N = 3），用种植体覆盖义齿修复。8年后的结果包括生存率、种植体周围骨水平、软组织反应和修复问题。（2）临床前试验：10只新西兰绵羊双侧股骨髁各植入4颗种植体：南方种植体的一体式ZC或Ti种植体，与临床试验相同，以及对照组：具有相同表面的南方ITC两件式种植体或诺贝尔（NBC）阳极氧化（TiUnite™）表面种植体。在无负载愈合12周后测量骨-种植体接触百分比（%BIC）。
召回了24名平均年龄75±8岁参与者中的8名（33%）；原参与者中有21%死亡，46%无法联系到。80.4%的种植体存活；排除腭部部位后，Ti种植体的存活率为87.5%，ZC种植体为79%。所有失败的种植体均在上颌。3颗ZC种植体发生断裂。Ti和ZC的骨丢失情况相似；Ti种植体的袋深度（P = 0.04）和附着水平（P = 0.02）大于ZC种植体。（分别为1.7±1.6毫米和1.6±1.3毫米）。绵羊股骨中的所有种植体均存活。一体式喷砂表面Ti种植体（80±19%）与ZC种植体（76±20%）或ITC种植体（75±16%）的%BIC在统计学上无差异；NBC的%BIC显著高于ITC（84±17%，P = 0.04）。
ZC和Ti一体式种植体的短期临床前结果显示，在无负载的股骨部位骨-种植体接触良好。这与老年无牙患者的长期临床结果不同。虽然ZC和Ti种植体表现出同等性能，但老年全口无牙患者种植体周围炎和种植体丢失的风险仍是一个重要因素。
