Diagnostic Accuracy of Plaster Vs Printed Models

Abstract

INTRODUCTION: Computers are important in all work streams. Digital photographs,radiographs and electronic charts were established in orthodontic practices in the 1990s. The ortho CAD, printed models, e-models and orthography gives 3 dimensional images of the patients who give the plaster models or alginate impression.The 3D printed  models can be stored, manipulated and measured using a standard personal computer. The plaster study models with virtual images have many advantages like  ease of access, storage and transfer along with  the accuracy of image capture techniques has been reported.Digital orthodontic values were equivalent to those obtained from plaster models. Although the data found in this evaluation is of varying quality, the use of digital models as an alternative to traditional measuring on plaster models may be advocated.

AIM: aim of the study is to determine the diagnostic accuracy of plaster and printed models. MATERIALS AND METHODS: 5 patients were randomly selected and impressions of the upper and lower arches were taken, the plaster models were made with the impressions. Then the patient’s upper and lower jaws were scanned using a scanner, it was designed in CAD CAM and  printed using  a 3 D printer.The measurements taken were 1.mesio distal width of the teeth. 2. Cervico- incisal length. 3.Inter canine width.4. Inter molar width. These measurements were measured using a digital vernier caliper  on the plaster models and printed models and the mean values were statistically analyzed.

RESULTS: In this chi- square value was >0.05 with  df=2 for the maxilla and hence it is statistically significant, for the mandible the chi-square value is <0.05 with df=2  hence it is statistically not significant.

CONCLUSION: In this study the mean values of printed models were higher for both maxilla and mandible  when compared to the plaster models. Hence it is concluded that printed models have  good diagnostic accuracy when compared to the conventional plaster models.