Digital morphology comparisons between models of conventional intraoral casting and digital rapid prototyping

Rapid prototyping (RP) technology used in digital design of dental industry has been rapidly developed. Most users in dental industry have concerned accuracy of the dental model printed by an RP device in comparison to that of a conventional intraoral impression. Thus, the purpose of the study was to compare digital morphology of a subject’s teeth between a dental impression and a printed dental RP model of the same subject whose digital dental morphology was created. In this study, one subject’s entire oral teeth was impressed and casted; a plastic RP model was also produced after the subject’s teeth were scanned using an intraoral scanner (3Shape TRIOS) to produce a whole dental images in digits. In order to digitally compare morphological dimensions between the impression and RP models, each model’s shape and dimension were scanned using a reverse engineering based optical scanner in producing digital dental images in 3D, a STL based format; meanwhile, a quality control industrial software (ATOS GOM Inspect V7.5 SR1) was used to compare the STL format based digital images of each model. The preliminary findings of the study show that an increased diverse visual coloring based error distribution of the scanned images between the RP plastic and dental impression casting models was found as well as a maximum average morphological error (0.1409mm) over eleven selected spots. The maximum relative errors could be due to a precision of the devices used in general during scanning and printing of an intraoral scanner and RP device, respectively, in addition to the errors from hardware and software operated during image reconstruction. In the future, an increased sample size of comparisons among impaired morphology in teeth, various usages of intraoral scanners or optical based scanners, specifically, will gain a better statistical meaningful finding of the study.*