Reducing subjectivity in the evaluation of pre‐clinical dental preparations for fixed prosthodontics using the Kavo PrepAssistant^®

Abstract

The evaluation of pre-clinical technical achievement in fixed prosthodontics cannot be objective when using visual examination of dental preparations. This is, however, still the main method used in dental schools. The present study introduces a new method, based on a mathematical formula, to reduce the problem. The idea emerged when using the Kavo PrepAssistant system (software version 1.05). This system is a 3D-scanner with software that can quantify geometrical differences between an instructor and student dental preparation in model teeth. Therefore, a mathematical formula was created, integrating selected clinically relevant geometric characteristics of dental preparations measured by the system. In this new formula, 70% of the evaluation parameters were computer analysed, whilst 30% were visually evaluated. This new method was compared with the traditional visual evaluation system during a pre-clinical practical examination, with the participation of 25 students. Using both methods to evaluate the 25 preparations, results showed similar grading for both methods (K-S test = 0.16; P < 0.05). Although this method does not provide overall clinical evaluation of student performance these results suggest that it can be helpful accessing technical achievement. In this method, the student has the guarantee that 70% of his/her grade results from an objective computer evaluation, with the possibility to visualise the mistakes with the software. It also reduces problems related to the calibration between different examiners. The Kavo PrepAssistant is a powerful tool in pre-clinical teaching, but has some drawbacks. It has to be developed towards the actual needs of pre-clinical departments, in order to achieve its full potential, as described in this study.

Evaluation of the Effectiveness of Computer Assisted Learning to Improve the Clinical Examination Skills of First Year Medical Undergraduates

“…This is consistent with study by Dewhurst et al in intestinal absorption physiology study in America [17]. Some studies even demonstrated that students studied with CAL need shorter time to reach the learning objectives, achieving better results than students who did not have access to CAL [18,19]. A study done by Govindaraja found that CAL makes undergraduate students understanding better in both theoretical as well practical aspects and helps them fulfill the learning outcomes [20].…”

“…Undoubtedly the approach of students will not be the same as that of teachers. There should be consistent feedback from students [25,26]. In this study many students mentioned that CAL cannot provide actual feel of clinical examination of human subject.…”

Preliminary study on the quantitative analysis of tooth preparation for crown based on digital model

“…Meanwhile, in the computer-aided evaluation systems, such as PREPassistant, 3D data of tooth preparation are obtained for viewing, while the geometric variations are also processed in 2D planes [15] . In this study, the overall distribution of the amount of tissue reduction was obtained by a 3D distance analysis between the prepared and intact tooth.…”

“…While some researchers have obtained the taper, tissue reduction and marginal width of the preparation by manual measurement [12][13][14] , the accuracy and repeatability of these measurements are to some extent limited since the geometric form of the preparation is irregular, as well as there are still differences between the surveyors. Recently, computer-aided methods have been developed for objective evaluation of tooth preparation, for example, the PREPassistant system (KAVO Dental GmbH, Germany), developed for pre-clinical training, can analyze the geometric variations in prepared artificial teeth at given points based on image processing [15][16][17] , in addition, Yayoi et al [18] obtained the axial wall taper of the prepared tooth by using a computerized calculation method.…”

“…Apart form the fact that some of the parameters for tooth preparation (such as tooth reduction amount and taper) have been obtained by manual measurement [12] , research based on computer-aided method has focused mainly on the application of the preclinical training system (PREPassistant system) [15][16][17] . Hence in this study, we investigate a clear process for a 3D evaluation system for tooth preparation, by obtaining the quantitative parameters for tooth preparation based on 3D scanning and reverse engineering (RE) technique.…”