STATEMENT OF PROBLEM Digital scans have increasingly become an alternative to conventional impressions. Although previous studies have analyzed the accuracy of the available intraoral scanners (IOSs), the effect of the light scanning conditions on the accuracy of those IOS systems remains unclear. PURPOSE The purpose of this in vitro study was to measure the impact of lighting conditions on the accuracy (trueness and precision) of different IOSs. MATERIAL AND METHODS A typodont was digitized by using an extraoral scanner (L2i; Imetric) to obtain a reference standard tessellation language (STL) file. Three IOSs were evaluated-iTero Element, CEREC Omnicam, and TRIOS 3-with 4 lighting conditions-chair light 10 000 lux, room light 1003 lux, natural light 500 lux, and no light 0 lux. Ten digital scans per group were recorded. The STL file was used as a reference to measure the discrepancy between the digitized typodont and digital scans by using the MeshLab software program. The Kruskal-Wallis, 1-way ANOVA, and pairwise comparison were used to analyze the data. RESULTS Significant differences for trueness and precision mean values were observed across different IOSs tested with the same lighting conditions and across different lighting conditions for a given IOS. In all groups, precision mean values were higher than their trueness values, indicating low relative precision. CONCLU-SIONS Ambient lighting conditions influenced the accuracy (trueness and precision) of the IOSs tested. The recommended lighting conditions depend on the IOS selected. For iTero Element, chair and room light conditions resulted in better accuracy mean values. For CEREC Omnicam, zero light resulted in better accuracy, and for TRIOS 3, room light resulted in better accuracy.

Polymer additive manufacturing (AM) technologies have been incorporated in digital workflows within implant dentistry. This article reviews the main polymer AM technologies in implant dentistry, as well as their applications in the field such as manufacturing surgical guides, custom trays, working implant casts, and provisional restorations.

Purpose To review the primary additive manufacturing (AM) technologies used to fabricate metals in implant dentistry and compare them to conventional casting and subtractive methods. Methods The literature on metal AM technologies was reviewed, and the AM procedures and their current applications in implant dentistry were collated and described. Collection of published articles about metal AM in dental field data sources: MEDLINE, EMBASE, EBSCO, and Web of Science searched. All studies related to AM technology description, analysis, and evaluation of applications in implant dentistry, including AM titanium (Ti) dental implants, customized Ti mesh for bone grafting techniques, cobalt‐chromium (Co‐Cr) frameworks for implant impression procedures, and Co‐Cr and Ti frameworks for dental implant‐supported prostheses were reviewed. Results Literature has demonstrated the potential of AM technologies to fabricate dental implants, root‐analog implants, and functionally graded implants; as well as the ability to fabricate customized meshes for bone grafting procedures. Metal AM technologies provide a reliable method to manufacture frameworks for implant impression procedures. Co‐Cr and Ti AM frameworks for implant‐supported prostheses provide a clinically acceptable discrepancy at the implant‐prostheses interface. Conclusions Additional clinical studies are required to assess the long‐term clinical performance, biological and mechanical complications, and prosthetic restoration capabilities of additively manufactured dental implants. Moreover, further studies are needed to evaluate their long‐term success and survival rates and biological and mechanical complications of AM implant‐supported prostheses.

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