Assessment of Porcelain Fused to Metal Crown Preparations by General Practitioners in Saudi Arabia
Mohammed M. Al-Moaleem *
Department of Prosthetic, College of Dentistry, Jazan University, Jazan, Saudi Arabia.
Nasser S. Al Hashim
Department of Prosthodontics, King Fahad Specialist Hospital, Dammam, Saudi Arabia.
Khalid A. Asiri
Department of Prosthodontics, Armed Force Hospital, Khamis Mushait, Saudi Arabia.
Essa A. Al Makhloti
Primary Health Care, Ministry of Health, Jazan, Saudi Arabia.
Nasser M. Al Ahmari
Resident in Prosthetic Program in Saudi Board, Jeddah, King Faisal Medical City, Abha, Saudi Arabia.
Shreyas Tikare
Preventive Dental Science Department, King Khalid University, Abha, Saudi Arabia.
*Author to whom correspondence should be addressed.
Abstract
Background: Principles for fabricating prosthetic restorations include sufficient axial preparation and adequate occlusal clearance of the prepared teeth. This study measured the convergence angles in the prepared teeth for porcelain fused to metal (PFM) crowns done by general practitioners in different regions of Saudi Arabia. In addition, the presence of planar occlusal reductions, functional cusp bevels and rounded angles in prepared casts were evaluated.
Methods: Sixty dies were selected from the working casts of prepared PFM crowns by general dental practitioners. The dies were divided into four equal groups according to the region. All the measured dies were mounted with the occlusal plane of the prepared teeth parallel to the floor. Photographs of buccal and proximal aspects of the dies were taken and then transferred into a personal computer. An AutoCAD software program was used to measure the mesiodistal and buccolingual convergence angles. The planar occlusal reduction, functional cusp bevel and presence of rounded angles of each preparation were evaluated. The data were recorded, then analyzed using SPSS version 20.0.
Results: The mean convergence angles were high above the ideal range (4º-14º) in all of the selected regions. The mean mesiodistal convergence angle nearest to the ideal range was registered in teeth prepared in Dammam region, which was lower than tooth preparations from Jeddah, Abha and Jazan regions. Statistically significant differences with buccal, lingual taper and buccolingual convergence existed between the regions. Also significant differences were observed between the teeth preparation samples from four regions with distal taper and mesiodistal convergence angles.
Conclusion: The achieved convergence angles of tooth preparations for PFM crowns by different general practitioner were out of the recommended range mentioned in dental literature.
Keywords: Porcelain fused to metal, tooth preparation, general practitioners, functional cusp, planar reduction, Saudi Arabia