Lee Du-Hyeong, Mai Hang-Nga, Li Lin-Jie, Lee Keun Woo
Assistant Professor, Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, South Korea; and Graduate Student, Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, South Korea.
Graduate student, Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, South Korea.
J Prosthet Dent. 2016 Jul;116(1):67-73. doi: 10.1016/j.prosdent.2015.12.007. Epub 2016 Feb 9.
The accuracy of computer-assisted design and computer-assisted manufacturing (CAD/CAM) screw channel drilling guide for locating the abutment screw has not been demonstrated.
The purpose of this in vitro study was to evaluate the accuracy of a CAD/CAM guide for drilling the screw access channel in angled implants.
Eighteen students prepared screw access channels through the crowns and abutments of implants placed at 0-, 15-, and 30-degree angulations in the mandibular second molar on dental casts. Experimental and control groups differed in the use of a CAD/CAM screw channel drilling guide, and each group was subdivided according to implant angulation. The accuracy of the screw channel was evaluated with regard to position and angle. Surface and volume losses of crowns and abutments were used to evaluate damage to the implanted prostheses. Statistical significance was assessed using 2-way analysis of variance (ANOVA), followed by the Tukey honestly significant difference (HSD) test (α=.05).
The implant angulation significantly influenced the effect of the drilling guide with regard to the accuracy of the screw channel (F=8.319, P<.001) and crown volume loss (F=4.474, P=.014). For the 30-degree angulation, the guided drilling group exhibited smaller screw access holes than the freehand drilling group (P<.001), whereas no statistical differences were found between the groups for the 0- or 15-degree angulation. Guided drilling groups showed smaller standard lateral deviations than the freehand drilling groups. No significant differences were found in abutment volume loss among the groups.
A CAD/CAM guide significantly enhanced the accuracy of drilling the screw channel and reduced damage to the crown and abutment, particularly at an implant angulation of 30 degrees.
计算机辅助设计与计算机辅助制造（CAD/CAM）用于定位基台螺钉的螺钉通道钻孔导板的准确性尚未得到证实。
本体外研究的目的是评估CAD/CAM导板在倾斜种植体中钻螺钉通道的准确性。
18名学生在牙模上下颌第二磨牙处制备穿过0°、15°和30°倾斜种植体的牙冠和基台的螺钉通道。实验组和对照组在是否使用CAD/CAM螺钉通道钻孔导板方面存在差异，且每组均根据种植体角度进行细分。从位置和角度方面评估螺钉通道的准确性。使用牙冠和基台的表面及体积损失来评估植入假体的损伤情况。采用双向方差分析（ANOVA）进行统计学显著性评估，随后进行Tukey诚实显著性差异（HSD）检验（α = 0.05）。
种植体角度对钻孔导板在螺钉通道准确性（F = 8.319，P <.001）和牙冠体积损失（F = 4.474，P =.014）方面的效果有显著影响。对于30°倾斜度，导向钻孔组的螺钉通道孔比徒手钻孔组小（P <.001），而在0°或15°倾斜度时，两组之间未发现统计学差异。导向钻孔组的标准侧向偏差比徒手钻孔组小。各组之间基台体积损失未发现显著差异。
CAD/CAM导板显著提高了螺钉通道钻孔的准确性，并减少了对牙冠和基台的损伤，尤其是在种植体倾斜度为30°时。
