Ministry of Health and Population, Cairo, Egypt.
Faculty of Dentistry, Tanta University, Tanta, Egypt.
BMC Oral Health. 2024 Oct 30;24(1):1318. doi: 10.1186/s12903-024-05037-4.
Placing implants deep sub-gingivally may affect the accuracy of implant impression techniques and the fit of final restoration.
The aim of this in-vitro study was to evaluate the effect of soft tissue thickness on accuracy of conventional and digital implant impression techniques.
Four parallel implant analogues (A, B, C, D) placed in each of two epoxy resin models representing edentulous mandible covered by flexible polyurethane material with two different thickness two mm and four mm. A total of sixty impressions performed, thirty impressions for each model divided into four groups (n = 15 per group) GI (C2mm) open tray impression with two mm implant depth, GII (C4mm) open tray impression with four mm implant depth, GIII (D2mm) digital impression with two mm implant depth, GIV (D 4 mm) digital impression with four mm implant depth. Impressions from open tray technique were poured to get stone casts while impressions from digital scanning technique were printed as three-dimensional printed casts. The six inter-implant distances between analogues were measured using Co-ordinate measuring machine, deviations compared to reference models were calculated. Data was collected, tabulated and statistically analyzed using One-way ANOVA test to detect significances between groups.
For conventional impressions there was significant difference between C2mm/C4mm (P < 0.001) regarding interimplant distance, while in digital impressions there was no significant difference between D2mm/D4mm AB(p = 0.110), BC(p = 0.066), CD(p = 0.710), AD(p = 0.084), AC(p = 0.067) and BD(p = 0.072). There was significant difference between conventional and digital impression techniques C2mm/D2mm, C4mm/D4mm (P < 0.001).
Within the limitations of this in-vitro study digital impressions provide more accurate outcomes with implants placed deeper subgingivally than conventional impressions.
Retrospectively registered.
将种植体深置于龈下可能会影响种植体印模技术的准确性和最终修复体的适配性。
本体外研究的目的是评估软组织厚度对传统和数字种植体印模技术准确性的影响。
将四个平行的种植体模拟体（A、B、C、D）分别放置在两个环氧树脂模型中，每个模型代表无牙下颌，用柔性聚氨酯材料覆盖，厚度分别为 2mm 和 4mm。共进行了 60 次印模，每个模型分为 4 组（每组 15 个）：GI（C2mm）开放式托盘印模，种植体深度为 2mm；GII（C4mm）开放式托盘印模，种植体深度为 4mm；GIII（D2mm）数字印模，种植体深度为 2mm；GIV（D4mm）数字印模，种植体深度为 4mm。开放式托盘技术的印模用于浇铸石模型，而数字扫描技术的印模则打印为三维打印模型。使用坐标测量机测量模拟体之间的六个种植体间距离，计算与参考模型的偏差。使用单向方差分析（One-way ANOVA）检验收集、制表和统计分析数据，以检测组间的显著性差异。
对于传统印模，C2mm/C4mm 之间的种植体间距离有显著差异（P<0.001），而对于数字印模，D2mm/D4mm 之间的种植体间距离无显著差异（AB，p=0.110；BC，p=0.066；CD，p=0.710；AD，p=0.084；AC，p=0.067；BD，p=0.072）。传统印模技术和数字印模技术之间的 C2mm/D2mm 和 C4mm/D4mm 有显著差异（P<0.001）。
在本体外研究的限制范围内，与传统印模相比，将种植体深置于龈下时，数字印模提供了更准确的结果。
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