ABSTRACT
STATEMENT OF PROBLEM: The accuracy of printed implant surgical guides can be affected by different factors that negatively impact the planned implant position. How print orientation, storage time, and conditions influence manufacturing accuracy remains uncertain. PURPOSE: The purpose of this in vitro study was to evaluate the influence of print orientation, storage conditions, and storage time on the intaglio surface accuracy of implant surgical guides manufactured by using a stereolithography (SLA) printer. MATERIAL AND METHODS: A tooth-supported maxillary implant surgical guide design (control file) was used to fabricate the specimens (N=40, n=10). Four groups were created based on the print orientation used: 0 (Group 0), 45 (Group 45), 70 (Group 70), and 90 degrees (Group 90). The specimens were fabricated using an SLA printer (Form 3B+) and a biocompatible dental resin (Surgical Guide Resin V1) following the manufacturer's recommended protocol. Each group was divided into 2 subgroups based on the storage conditions: light (L subgroup) and dark (D subgroup) settings. Each specimen was digitized by using a desktop scanner (Medit T710) at days 0, 1, 7, and 14. The control file and each digitized specimen were superimposed by using the best-fit technique with a metrology program (Geomagic Control X). The root mean square (RMS) error was used to calculate the discrepancies between the control files and specimen files. Three-way ANOVA and pairwise comparison Tukey tests were used to analyze trueness. The Levene test was used to assess precision (α=.05). RESULTS: Significant trueness discrepancies were found among the groups tested (P<.001), but no significant differences were found among the subgroups (P=.100) and the storage times analyzed (P=.609). Additionally, the Tukey test showed significant RMS error mean value discrepancies between Group 0 and Group 45 (P<.001), Group 0 and Group 90 (P<.001), Group 45 and Group 70 (P<.001), and Group 70 and Group 90 (P<.001). The Levene test revealed significant SD discrepancies among the groups tested (P<.05). CONCLUSIONS: The trueness and precision of the intaglio surface of the implant surgical guides manufactured by using the printer and material tested were affected by the print orientation. However, storage conditions over a 14-day period did not impact the intaglio accuracy of the specimens.
ABSTRACT
Additive manufacturing (AM) has many advantages and became a valid manufacturing technique for polymers and metals in dentistry. However, its application for dental ceramics is still in process. Among dental ceramics, zirconia is becoming popular and widely used in dentistry mainly due to its outstanding properties. Although subtractive technology or milling is the state of art for manufacturing zirconia restorations but still has shortcomings. Utilizing AM in fabricating ceramics restorations is a new topic for many researchers and companies across the globe and a good understanding of AM of zirconia is essential for dental professional. Therefore, the aim of this narrative review is to illustrate different AM technologies available for processing zirconia and discus their advantages and future potential. A comprehensive literature review was completed to summarize different AM technologies that are available to fabricate zirconia and their clinical application is reported. The results show a promising outcome for utilizing AM of zirconia in restorative, implant and regenerative dentistry. However further improvements and validation is necessary to approve its clinical application.
