Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Oral (Radiology-Diagnosis)

Aim: To compare the dimensional accuracy of stereolithography (SLA) and fused deposition modelling (FDM), using 3D printed mandibular models based on CBCT scan data. Methodology: In this in vitro study, one mandibular model (Implant Bone Model: M450) was recruited. Ten linear measurements were measured directly on the model using digital caliper.Radio-opaque markers served as the reference standard for all measurements. The model was scanned using CBCT machine (i-CAT, KaVo dental, USA) at 120 KVp, 5 mA, for 8.9 seconds. CBCT scans were exported to two open source softwares (2InVesalius 33 software, InVesalius, Brazil, and 2Meshmixer 3.53, Autodesk, USA) for generating and optimizing the STL files. 3D printing was done using SLA (2Form 2 printer3, Formlabs, United States) and FDM using (2Zortax M300 printer3, Zortax, Poland). The scanned model was printed 7 times per each printer. Same ten linear measurements were recorded using the same digital caliper for all the printed models. Results: The precision of both SLA and FDM showed no statistical significant difference. Regarding the trueness, there was a statistical significant difference in the dimensional error of both techniques in comparison to the reference model. Where the mean relative difference was (0.154%, - 0.80%) and the mean absolute difference was (0.271 mm, -0.36 mm) for the SLA and FDM vii respectively. Upon comparing the two utilized 3D printing techniques to each other, the trueness of both the SLA and FDM showed no statistical or clinical significant difference in the dimensional error, with the mean relative difference and the mean absolute difference of SLA being lower than that of the FDM. High level of agreement in the repeatability of the measurements was demonstrated in this study, with strong intra- and inter-observer reliability

Issued also as CD