Precision of Digital Prosthodontic Planning for Oral Rehabilitation
Jaafar Abduo *
Melbourne Dental School, Melbourne University, 720 Swanston Street, Melbourne, Victoria, Australia. & School of Computer Science and Software Engineering, University of Western, Australia
Mohammed Bennamoun
School of Computer Science and Software Engineering, University of Western, Australia
Marc Tennant
School of Anatomy, Physiology and Human Biology, University of Western, Australia, 35 Stirling Highway, Crawley, Western Australia, Australia.
John McGeachie
School of Anatomy, Physiology and Human Biology, University of Western, Australia, 35 Stirling Highway, Crawley, Western Australia, Australia.
*Author to whom correspondence should be addressed.
Abstract
Aims: Recently, digital wax-up is proposed as a tool to aid prosthodontic planning. Accuracy is a requirement of the diagnostic wax-up in order for its information to be transferrable clinically.The purpose of this study is to evaluate the precision of digital prosthodontic planning in the form of digital wax-up.
Study Design: Comparative study.
Place and Duration of Study: Oral Health Centre of Western Australia and School of Computer Science and Software Engineering, University of Western Australia, from June 2012 to December 2013.
Methodology: Twenty-five dental arch models of 15 patients were collected. The models were duplicated twice to allow for the execution of conventional wax-up and digital wax-up. The conventional wax-up involved tooth modification with inlay wax. The digital wax-up was based on fitting average tooth forms on virtual pre-treatment models. For the analysis, the conventional wax-up models were converted to digital models. All the wax-up models were segmented to yield soft tissue and tooth-gingiva models. With the aid of the 3D image registration process, the segmented models were superimposed on the pre-treatment models to evaluate the accuracy of fit. Further, the gingival margin discrepancies of each wax-up protocol were evaluated.
Results: The image registration process revealed less discrepancies for the digital wax-up (soft tissue = 0.11mm, tooth-gingiva junction = 0.11mm) than the conventional wax-up (soft tissue = 0.18mm, tooth-gingiva junction = 0.20mm). Similarly, the gingival margin discrepancies were less for the digital wax-up. However, the patterns of discrepancies were similar for the two wax-up protocols.
Conclusion: In terms of accuracy and transferability, the digital wax-up is comparable to the conventional wax-up.
Keywords: Wax-up, digital, Micro-CT, dental model, image registration