Steam-sterilized and degradable fused filament fabrication-printed polylactide/ polyhydroxyalkanoate surgical guides for dental implants: Are they accurate enough for static navigation?

Abstract

Three-dimensional (3D) printing is a rapidly evolving field and has gained increasing importance in the medical sector. However, the increasing usage of printing materials is accompanied by more wastages. With a rising awareness of the environmental impact of the medical sector, the development of highly accurate and biodegradable materials is of great interest. This study aims to compare the accuracy of polylactide/polyhydroxyalkanoate (PLA/PHA) surgical guides printed by fused filament fabrication and material jetted guides of MED610 in fully guided dental implant placement before and after steam sterilization. Five guides were tested in this study and each was either printed with PLA/PHA or MED610 and either steam-sterilized or not. After implant insertion in a 3D-printed upper jaw model, the divergence between planned and achieved implant position was calculated by digital superimposition. Angular deviation and 3D deviation at the base and the apex were determined. Non-sterilized PLA/PHA guides showed an angle deviation of 0.38 ± 0.53° compared to 2.88 ± 0.75° in sterile guides (P > 0.001), an offset of 0.49 ± 0.21 mm and 0.94 ± 0.23 mm (P < 0.05), and an offset at the apex of 0.50 ± 0.23 mm before and 1.04 ± 0.19 mm after steam sterilization (P < 0.025). No statistically significant difference could be shown for angle deviation or 3D offset at both locations for guides printed with MED610. PLA/PHA printing material showed significant deviations in angle and 3D accuracy after sterilization. However, the reached accuracy level is comparable to levels reached with materials already used in clinical routine and therefore, PLA/PHA surgical guide is a convenient and green alternative.

A state-of-the-art guide about the effects of sterilization processes on 3D-printed materials for surgical planning and medical applications: A comparative study

“…This result is in line with Gielisch et al. [ 46 ] who compared the behavior of polylactide/ polyhydroxyalkanoate (PLA/PHA) surgical guides printed by FFF and MED610 guides printed by MJ in fully guided dental implant placement before and after steam sterilization, and the study found significant deviations in angles and accuracy in the PLA/PHA guide as compared to the MED610 guide. MED610 and Surgical Guide resin can also be used for the production of custom-made medical devices to support treatments with materials needing skin or mucous contact for less than 24 h [ 47 , 48 ] .…”

The Effect of Sterilization on the Accuracy and Fit of 3D-Printed Surgical Guides

“…This contradiction might be explained by the different 3D-printing methods, i.e., PolyJet 3Dprinting in the aforementioned study vs. DLP 3D-printing in the current study, the different tested materials, the different types of specimens and the different assessment methods. A recent study focusing on the accuracy of steam-sterilized printed surgical guides concluded that, at the implant base level, a high and significant deviation in the angle as well as in the 3D accuracy was measured after steam sterilization [39]. This study tested polylactide and polyhydroxyalkanoate surgical guides printed with the fused filament fabrication process and conducted a different methodology [39].…”

“…A recent study focusing on the accuracy of steam-sterilized printed surgical guides concluded that, at the implant base level, a high and significant deviation in the angle as well as in the 3D accuracy was measured after steam sterilization [39]. This study tested polylactide and polyhydroxyalkanoate surgical guides printed with the fused filament fabrication process and conducted a different methodology [39]. Another study tested the linear dimensional accuracy of SLA surgical guides, in contrast to our study, where all the guides were printed by the DLP process [40].…”