The Research Of Fabricating The Metal Base Of Complete Denture By 3D Printing Technique

PURPOSE: Te purpose of the study was to fabricate Co-Cr alloy and Ti alloy frameworks for a maxillary complete denture with Rapid Prototyping Technique,such as Selective Laser Melting(SLM)and Electron Beam Melting(EBM).The aim was to evaluate their microstructure and adaption from the die stone models.The objective of this research is to develop laser rapid forming method in making remove partial denture.METHODS: Part?: 1,40 pairs of edentulous casts were divided into 4 groups randomly and equally,either by SLM technique Co-Cr alloy and Ti alloy,or by conventional method Co-Cr alloy and Ti alloy.The base-cast sets were transversally sectioned into 3 sections at the distal of canines,mesial of first molars,and the posterior palatal zone.The gap between the metal base and cast was measured in the 3 sections.Take use of Stereoscopic microscope to measure the gap and analysis the record with SPSS statistical software.2,Manufacture 10 pairs of complete denture base of edentulous casts by EBM technique.The base-cast sets were transversally sectioned into 3 sections.Take use of Stereoscopic microscope to measure the gap and analysis the record with SPSS statistical software.Part ?:5 pieces of specimens of 5mm diameter were fabricated with Co-Cr alloy and Ti alloy by SLM?EBM and the traditional casting technology(the same in part 1).Take use of SEM to evaluate the differences of microstructure among these specimens.RESULTS: Part?: 1,There was no statistical difference among the 3 sections all 4 groups(P>0.05).At the region of canines,the clearance value of SLM Co-Cr alloy group was larger than that in conventional method group(P<0.05).At the mesial of first molars region and the posterior palatal zone,there was no statistical difference between the gaps in the two groups(P>0.05).There was statistical difference between SLM Co-Cr alloy and SLM Ti alloy group(P<0.05).There was no statistical difference between SLM Co-Cr alloy and conventional method Co-Cr alloy group.There was no statistical difference between SLM Ti alloy and conventional method Ti alloy group(P>0.05).2.There was statistical difference Among EBM Ti alloy,conventional method Ti alloy and SLM Ti alloy group(P<0.05).Part ?: The SLM Co-Cr alloy has denser microstructure behavior and less casting defect than the cast Co-Cr alloy.The SLM Ti alloy has more uniform and compact microstructure behavior than the cast Ti alloy and EBM Ti alloy.CONCLUSIONS: SLM technique showed initial feasibility to manufacture the dental base of complete denture and large sample studies are needed to prove its reliability in clinical application.The mechanical properties and microstructure of the denture frameworks prepared by selective laser melting indicate that these dentures are appropriate for clinical use.EBM technique is inadequate to make a complete denture now.It needs further research to improve the adaption of products.It may need to develop a specific manufacturing mode according to the denture requirement.