A Comparison of Convergence Angles of Crown preparations in an undergraduate programme at a Tertiary Institution





Convergence angles, full coverage crown preparation; dental students, preclinical prosthodontics


The retention of indirect dental restorations is of concern for clinicians as it influences the success of clinical outcomes. Retention and resistance are dependent on many factors including the convergence angles of the opposing axial wall tapers. Adequate axial wall taper is important in crown preparation to improve physical retention and increase resistance of the restoration. Aims and objectives To determine and compare the convergence angles (CA) of KaVo® teeth prepared for full coverage crown restorations by fourth year dental students in a preclinical fixed prosthodontics module in a five year dentistry training programme. Methodology Crown preparations produced by fourth year dental students at Sefako Makgatho Health Sciences University (SMU), South Africa, over a period of 3 years were included in this study. These preparations were digitally captured using CAD-CAM imaging technology. The images were analysed in ImageJ® software to determine the mesio-distal convergence angles. Statistical analysis was undertaken
using SPSS ver. 27 for Windows. Results The overall mean convergence angle of 15.38° ± 6.68° was computed for n=75 crown preparations. ANOVA revealed a significant difference (p<0.05) in the CA among the three cohorts (2017: 16.87° ± 6.94°; 2018: 17.23° ± 6.13°; 2019: 12.02° ± 5.86°). A reasonable proportion of dental students n=25 (33%) achieved the recommended CA of 6° to 12°.
This study indicates that with objective evaluation tools, it is possible to improve on the intended guidelines for crown preparations during undergraduate teaching and training in pre-clinical Fixed Prosthodontics.


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Author Biographies

Pusetso D Moipolai, MEd (Wits). Head of Department - Prosthodontics, SMU

Pagollang Motloba, Head of Department - Community Dentistry, SMU


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How to Cite

Naidoo, N. ., Moipolai, P. D., & Motloba, P. (2022). A Comparison of Convergence Angles of Crown preparations in an undergraduate programme at a Tertiary Institution. South African Dental Journal, 76(10), 602–606. https://doi.org/10.17159/2519-0105/2021/v76no10a3

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