The calibration of a software programme to assess ceramic crown preparations in a pre-clinical setting
Date
2016
Authors
Roopa, Variza Daya
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Abstract
Purpose
The use of the PrepCheck (v.1.1) software (Sirona Dental Systems GmbH, Germany) is to enable assessment of student tooth preparations to be digital, objective, accurate, consistent and reliable so that students can work independently. The software has its default parameters configured to arbitrary values which are not based on clinical evidence of tooth preparations. The aim of this study was to set new parameters of the software to realistically assess the quality of clinically acceptable ceramic crown preparations.
Method
Based on evidence in the literature a new assessment rubric for the evaluation of ceramic tooth preparations was created which allowed for grading of the preparations as Acceptable, Requires Modification or Unacceptable. Sixty preparations were made on typodont teeth for tooth numbers 11, 13, 15, 16, 36 (FDI system). For each tooth four preparations were made to meet all the requirements under the Acceptable Category, four with variations in taper, incisal/ occlusal reduction and axial reduction to be categorised as Requires Modification and four had further variations made so that they fall under the Unacceptable Category. The sixty preparations were assessed by five faculty instructors (acting as raters) at baseline and again after two weeks to assess intra- and inter-rater reliability. Once sufficient agreement had been reached, the software’s parameters were adjusted and the preparations were scanned and compared with the categorical assessment from the instructors. This process was repeated once to test whether the software had been successfully calibrated.
Results
The intra-rater agreement was substantial, with two raters having excellent intra-rater agreement. However, two raters had poor inter-rater agreement and were then excluded, after which the inter-rater reliability measured by Cohen’s kappa was 0.71, corresponding to ‘substantial’ agreement on both occasions. The majority decision rating from these assessments accurately resembled the intended rating and was used to compare the ratings of the software assessment using the default and new (rubric) parameter settings. The default settings performed poorly, whereas the new settings resulted in substantial agreement with the majority decision of the instructors (raters).
Conclusions
It was found that the default parameters of the software were unrealistic and not clinically based. The parameters required considerable modification to assist in the development of clinically acceptable preparations. The software shows great promise but the parameters have to be modified to be able to assess preparations that are more realistic for the clinical situation.
Description
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Dentistry.
School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, South Africa
Johannesburg, 2016
Keywords
Ceramic Crown Preparations