The Evaluation of undercuts appearance in teeth preparations

Abstract

Introduction Undercuts are portions of the tooth preparation surface that are below the height of contour. They are ambiguous factor for the retention reduction or increase. However, there is no accurate data about undercuts appearance in preparations. Aim The aim of this study was to evaluate undercuts’ appearance in preparations of general dental practitioners (GDP) and Lithuanian University of Health Sciences (LSMU) Odontology Faculty (OF) 3rd course students. Objectives 1. To evaluate undercuts appearance in LSMU OF 3rd course students’ and GDP preparations. 2. To evaluate undercuts appearance and their relation in preparations’ walls. 3. To evaluate undercuts appearance in jaws and different groups of teeth GDP preparations. 4. To evaluate undercuts appearance in jaws and different groups of teeth in LSMU OF 3rd course students’ preparations. Methods 94 models with 159 teeth preparations were selected from 9 GDP. 55 teeth preparations were selected from Prosthodontics (preclinical course) exam of LSMU OF 3rd course students. All chosen preparations were only for single crowns. Once conductive lacquer was removed with acetone, all preparations were fixed in standardized holders, sprayed with occlusion spray (Occlusions – Tuschier – Spray Grün, Germany) and scanned with CAD/CAM scanner (Ceramill Map 300, Austria, 2013). Undercuts’ appearance was evaluated with Ceramill Map – v2.5.02 program. The greatest undercuts’ depths were fixed. Statistical data analysis was performed by using SPSS 21.0.0.0. Qualitative[...].