Impact of Autoclaving on the Dimensional Stability of 3D-Printed Surgical Guides for Aesthetic Crown Lengthening.

The aim of this study was to evaluate the impact of autoclaving on the dimensional stability of surgical guides (SGs) for aesthetic crown lengthening (ACL) using different resins/printing methods. Fifty SGs for ACL were printed using five different resin/printer combinations (FL, SR, ND, KS and VC). All the SGs were scanned before (T0) and after (T1) sterilization. Autoclaving was conducted at 134 °C during 4 min. The STL files of each SG at T0 and T1 were compared with the original design (TR). Dimensional stability was measured using trueness and precision. Deviations from TR to T1 were calculated in the three space axes and by measuring the area between three reference landmarks. At T0, the FL group showed the best trueness and precision, while the SR group performed significantly worse than the other groups. At T1, all the groups except VC exhibited significant dimensional alterations compared with T0. Also, VC showed the best trueness and precision values. All the groups had a significant deviation in at least one space axis, while only the SR group exhibited significant variations from T1 to TR in the area between the reference landmarks. Most of the evaluated resin/3D printer combinations suffered significant dimensional alterations after autoclaving.