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The reliability of an easy measuring method for abutment convergence angle with a computer-aided design (CAD) system
Yong-Joon Seo1, Taek-Ka Kwon2, Jung-Suk Han1
1Department of Prosthodontics, Seoul National University School of Dentistry, Seoul, Republic of Korea.
Purpose:
The purpose of this study was to evaluate the intra-rater reliability and inter-rater reliability of three different methods using a drawing protractor, a digital protractor after tracing, and a CAD system.
Materials And Methods:
Twenty-four artificial abutments that had been prepared by dental students were used in this study. Three dental students measured the convergence angles by each method three times. Bland-Altman plots were applied to examine the overall reliability by comparing the traditional tracing method with a new method using the CAD system. Intraclass Correlation Coefficients (ICC) evaluated intra-rater reliability and inter-rater reliability.
Results:
All three methods exhibited high intra-rater and inter-rater reliability (ICC>0.80, P<.05). Measurements with the CAD system showed the highest intra-rater reliability. In addition, it showed improved inter-rater reliability compared with the traditional tracing methods.
Conclusion:
Based on the results of this study, the CAD system may be an easy and reliable tool for measuring the abutment convergence angle.
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