Abstract
OBJECTIVES: To investigate Martens hardness parameters of splint materials after storage in liquids and toothbrush simulation. MATERIALS AND METHODS: Ten specimens per material and group were fabricated (hand-cast CAST, thermoformed TF, CAD/CAM-milled CAM, 3D-printed PS, PL, PK, PV), stored in air, water, coffee, red wine, and cleaning tablets and investigated after fabrication, 24 h, 2- and 4-week storage or toothbrushing. Martens hardness (HM), indentation hardness (H(IT)), indentation modulus (E(IT)), the elastic part of indentation work (η(IT)), and indentation creep (C(IT)) were calculated (ISO 14577-1). STATISTICS: ANOVA, Bonferroni post hoc test, between-subjects effects, Pearson correlation (α = 0.05). RESULTS: HM varied between 30.8 N/mm(2) for PS (water 4 weeks) and 164.0 N/mm(2) for CAM (toothbrush). H(IT) values between 34.9 N/mm(2) for PS (water 4 weeks) and 238.9 N/mm(2) for CAM (toothbrush) were found. E(IT) varied between 4.3 kN/mm(2) for CAM (toothbrush) and 1.8 kN/mm(2) for PK (water 2 weeks). η(IT) was found to vary between 16.9% for PS (water 4 weeks) and 42.8% for PL (toothbrush). C(IT) varied between 2.5% for PL (toothbrush) and 11.4% for PS (water 4 weeks). The highest impact was identified for the material (p ≤ 0.001). CONCLUSIONS: Storage and toothbrushing influenced Martens parameters. The properties of splints can be influenced by the choice of materials, based on different elastic and viscoelastic parameters. High HM and E(IT) and low C(IT) might be beneficial for splint applications. CLINICAL RELEVANCE: Martens parameters HM, E(IT), and C(IT) might help to evaluate clinically relevant splint properties such as hardness, elasticity, and creep.