Attending Physician, Department of Stomatology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, PR China.
Attending Physician, Changjie Dental Clinic, Jiaxing, PR China.
J Prosthet Dent. 2020 Apr;123(4):622-629. doi: 10.1016/j.prosdent.2019.04.010. Epub 2019 Aug 2.
Residual cement is detrimental to the long-term success of dental implants with a cement-retained restoration. The complete elimination of excess cement remains a challenge.
The purpose of this in vitro study was to evaluate the effects of precementation technique on minimizing the residual cement and retention of restorations.
Four custom cobalt-chromium alloy (Co-Cr) abutments were manufactured by computer-aided design and computer-aided manufacturing (CAD-CAM) as precementation abutments with height and radius reductions of 25 μm (A25), 50 μm (A50), 75 μm (A75), and 100 μm (A100). Fifty CAD-CAM-fabricated standard Co-Cr abutments and corresponding crowns were randomly matched and treated as follows: 10 specimens were cemented with the conventional cementation procedure with glass ionomer cement (G0), and 40 were precemented with precementation abutments (n=10) before the definitive cementation with standard abutments (G25, G50, G75, G100). The weight of the cement in the cement space was calculated, and the marginal sealing was evaluated by using a stereoscopic microscope. The effects of precementation with resin cement on minimizing residual cement around the marginal area of dental implants were further evaluated extraorally. The influence of precementation with glass ionomer and resin cement on the retention force was analyzed by using a universal testing machine at a crosshead speed of 0.5 mm/min. One-way ANOVA was used to analyze cement mass and marginal sealing values. Two-way ANOVA was used to compare the retention forces (α=.05).
The cement weight of G50 (7.2 ±0.6 mg) was significantly higher than that of G25 (6.0 ±1.1 mg, P<.05), while no significant differences in cement weights were found among G50, G75, and G100. Consistently, the G50, G75, and G100 had higher marginal sealing values than that of the G25 (P<.01). Extraoral experiments showed that the precementation with A50 reduced subgingival residual cement without affecting retention.
These in vitro results suggest that precementation with a precisely manufactured precementation abutment minimized the residual cement around implant abutments, and 50 μm could be a preferable precementation space.
残留的粘结剂会对保留修复体的牙种植体的长期成功产生不利影响。完全清除多余的粘结剂仍然是一个挑战。
本体外研究的目的是评估预粘结技术对最小化残留粘结剂和保留修复体的影响。
通过计算机辅助设计和计算机辅助制造（CAD-CAM）制造了四个定制的钴铬合金（Co-Cr）基台作为预粘结基台，高度和半径分别减少了 25μm（A25）、50μm（A50）、75μm（A75）和 100μm（A100）。50 个 CAD-CAM 制造的标准 Co-Cr 基台和相应的冠随机匹配并进行以下处理：10 个样本用玻璃离子水门汀（G0）进行常规粘结程序粘结，40 个样本用预粘结基台（n=10）预粘结，然后用标准基台（G25、G50、G75、G100）进行最终粘结。计算粘结剂空间中的粘结剂重量，并使用立体显微镜评估边缘密封情况。进一步通过体外实验评估树脂粘结剂预粘结对牙种植体边缘区域残留粘结剂的最小化效果。通过万能试验机以 0.5mm/min 的十字头速度分析玻璃离子和树脂粘结剂预粘结对保持力的影响。采用单因素方差分析（ANOVA）比较粘结剂重量和边缘密封值，采用双因素方差分析（ANOVA）比较保持力（α=.05）。
G50 的粘结剂重量（7.2±0.6mg）明显高于 G25（6.0±1.1mg，P<.05），而 G50、G75 和 G100 之间的粘结剂重量无显著差异。一致地，G50、G75 和 G100 的边缘密封值均高于 G25（P<.01）。体外实验表明，A50 的预粘结可减少龈下残留粘结剂而不影响保持力。
这些体外结果表明，使用精确制造的预粘结基台进行预粘结可最大程度地减少种植体基台周围的残留粘结剂，50μm 可能是一个更合适的预粘结空间。
