ABSTRACT
CONTEXT: Students can have some issues in the comprehension and execution of coronal preparations in fixed partial prosthesis (FPP). Some issues pertain to the amount of reduction, the inclination, and the positioning, all of which are important for the execution of an ideal preparation while respecting the required biomechanical principles. OBJECTIVE: The present study's aim was to evaluate the main problems experienced by graduation students regarding coronal preparation in FPP and to suggest teaching skills to help students and professors. DESIGN: A total of 87 students, who were enrolled in the 3rd year of Dentistry at the FPP course - in the Institute of Science and Technology, São Paulo State University, between 2017 and 2018, participated in the study. Two methodologies were developed, applied, and validated: first, a mannequin with a scheme of colors to help students visualize the coronal preparation; second, a comparison of different didactic methods. RESULTS: Only 54.02% of the students answered the questionnaire, and the main problem identified by the respondents was the amount of reduction required (78.2%). In the second place, 50.9% of the students stated that they had problems with the inclination and angle of the preparation. The mannequin method with color schemes was approved by 91.5%. The favorite didactic method was a live demonstration (face to face), with 61.8%. In the second place, 47.3% of the students stated that live projection was also adequate. CONCLUSIONS: Both auxiliary didactic methods were approved by the students and they reported that it helped them to visualize the amount of reduction necessary and the sequence of the preparation. Hence, it was concluded that the mannequin with color schemes and the live projection were approved as auxiliary didactic resources for teaching FPP.
Subject(s)
Dental Implants , Humans , Manikins , Students , Surveys and Questionnaires , Teaching , UniversitiesABSTRACT
BACKGROUND: The rehabilitation of canine guidance can be performed with adhesive indirect materials, but can the restoration thickness be reduced without mechanical disadvantages? Thus the goal of this study was to analyze the stress of upper canines which received different thicknesses of ceramic fragments for the rehabilitation of the canine guidance using finite element analysis. METHODS: A superior canine was modeled using a computer aided design software. The dental tissues were individually shaped containing enamel, dentin and periodontal ligament. The following three different ceramic fragment thicknesses were then implemented: 0.3, 0.7 and 1.5 mm. Lithium disilicate was chosen as the ceramic material. The solid geometries were exported to the analysis software. The materials were considered isotropic, homogeneous and linear. The set was submitted to efforts in the incisal third in the palatine face to analyze maximal principal stress, mimicking mandibular lateral movement. The applied load was 100N, and the fixation region was on the medullary bone. RESULTS: For restoration, the thinner the ceramic, the higher the stress concentration was; while for the adhesive surface of teeth, the thicker the ceramic, the higher the stress concentration. CONCLUSIONS: The smaller the ceramic thickness was, the lower stress concentration showed at the adhesive interface, while the stress concentration was higher on the restoration intaglio surface.
