A comparison of the accuracy of three types of 3 dimensional scanners for recording patients' study models and the ease of use of each scanner.

Abstract

Statement of problem: Dental study models are classed as a patient's dental record and as a result, they need to be retained for a minimum amount of time for medico-legal purposes. With the ever-increasing dental care, the storage of these models has started to become a problem in dental hospitals, surgeries and laboratories. Purpose: This thesis will compare three different types of three-dimensional scanners, in terms of accuracy and ease of use to determine whether a three-dimensional scanning technique can be utilised to minimise the problems associated with the current system of storage. Material and methods: One set of orthodontically trimmed models was selected as a master model and landmarks that utilised flat planes were accurately machined on to each model. Manual measurements were taken using these landmarks and used as a benchmark. The master model was scanned using each scanner and the surfaces acquired were imported into 'Magics' were the same measurements were taken. The measurements obtained from each of the scanned surfaces were compared to the manual measurements. A scoring system was developed to aid the assessment of the three scanning techniques. Results: The analysis revealed that, the manual measurements of the study models were the most reliable. The touch probe scanner was the easiest to use and the most compact. The structured light scanner was the most accurate with all of the average landmark measurements < l0.5mm to those of the manual measurements, and also produced the surface with the highest quality. The laser scanner performed the best for speed. Conclusion: Although the scanners demonstrated that the required accuracy and reliability is available, none of the systems were fast enough or at an obtainable price to make them a feasible solution to the problem of study model storage