Influence of DLP and SLA printer technology on the accuracy of surgical guides for implant dentistry in free-end situations

Aim: The present in vitro study aimed to compare the accuracy of the implant position inserted by surgical guides manufactured by three different 3D printers (one SLA and two DLP) and a subtractive manufacturing technique for a free-end situation.Materials and methods: Surgical guides were manufactured using three different 3D printers, one SLA printer (Form 2; Formlabs) and two DLP printers (D20 II; Rapid Shape, and SolFlex 350; W2P Engineering). Surgical guides manufactured using the conventional CAD/CAM-based subtractive method served as controls. In total, 48 surgical guides were printed and assessed for accuracy. The guides were used for the placement of implants at tooth position 37. The postoperative implant position was digitally scanned for metric comparison with the preoperatively planned implant position.Results: Significant differences were found when the SLA and DLP printers were compared. The SLA printer showed significantly lower accuracy in implant displacement at crest (P= 0.032) and angular displacement (P= 0.049) compared with the two DLP printers. The DLP printers showed comparable values to the control group. The results were within an acceptable clinical range.Conclusion: DLP technology seems to be superior to conventional SLA technology in terms of the accuracy of 3D-printed surgical guides when used for placement of implants in free-end situations.