[Physical and mechanical properties of materials used in the technology of computer production of surgical templates].

Objective: The physical and mechanical properties of samples printed from different materials subjected to post-processing in a clinic were evaluated.

Material and methods: Studied hardness and modulus of elasticity before and after sterilization by autoclaving. Based on the analysis of the literature and monitoring of the dental materials market, our choice fell on the most popular materials for 3D printing of surgical templates for dental implantation, such as: material 1 (FormLabs Dental SG Resin (Formlabs, USA)) and material 2 (NextDent SG (NextDent, Netherlands)). In connection with the events of recent years, we also took into the study a domestically produced polymer - material 3 (HARZLabs Yellow Clear PRO (HARZLabs, Russia)).

Results: As a result of the study, it was found that in each of the groups of materials studied, the values of the elastic modulus of sterilized samples are higher than the elastic modulus of samples that have not undergone sterilization. According to GOST 31572-2012 (ISO 1567:1999 Polymeric materials for denture bases, non-sterilized samples of group 2 are considered not to have passed the test, since all three samples of the studied group have a crack resistance index of less than 1 MN/m1.5. Crack resistance index of sterilized samples of the group of materials 2 is also close to 1. Samples of group 1 (both sterilized and non-sterilized) have the highest crack resistance. This group also has the highest flexural strength. On non-sterilized samples of material 1, there was no crack initiation along the cut and groove. The samples of other groups were mainly destroyed along the axis of the groove.

Conclusion: Analyzing the obtained data and considering that all studies carried out were in accordance with dental standards, the researchers concluded that the increase in flexural strength after sterilization by autoclaving and the feasibility of using material 1 for the production of surgical templates in accordance with all manufacturer's recommendations.