A Novel Methodology of Convergence Angle Assessment Using Professional Computer-Aided Design Software

Abstract

Background: Convergence angle (CA) is a key determinant of tooth preparation quality, yet its ideal range is difficult
to achieve and accurately measure in clinical settings. Existing research mainly reports CA within single experience
groups and rarely evaluates operator or tooth related factors. This study introduces a novel 3D scanned methodology
to assess CA in actual patient preparations, addressing gaps in previous literature. Purpose of the study: The purpose
of the study is to evaluate the CA of coronal preparation of actual patients utilizing 3D digitally scanned models and
professional computer-aided design (CAD) software. Materials and Methods: Dental stone casts were randomly
collected from dental schools, dental laboratories, and general practices. Twenty (n = 20) preparations were randomly
selected from the collected stone casts of each group of dental professionals (students, general practitioners, and
restorative specialists). The stone casts were 3D scanned, digitized, and saved in standard tessellation language format,
which was then imported into CAD software for evaluation by one operator to measure the CA in the digital model.
Descriptive statistics, factorial multivariate analysis of covariance, and one-way analysis of covariance analyses were
conducted on the data.