Evaluation of water absorption and water solubility parameters of 3M «Protemp 4» and «HARZ Labs Dental Sand» materials

The objective of this work is to evaluate mass loss per unit volume in model composite samples from 3M «Protemp 4» material and temporary composite dental prostheses manufactured by 3D printing method from «HARZ Labs Dental Sand» material, as well as to investigate the degree of hydrophobicity of these materials. In addition, research was aimed at evaluation of the amount of substance that is released from materials in accordance with GOST 31574—2012 requirements for polymer materials. Materials and methods. Samples made from 3M «Protemp 4» material directly and temporary composite dental prostheses manufactured by 3D printing from «HARZ Labs Dental Sand» photopolymer material are considered. To evaluate the water absorption and water solubility parameters, 6 samples of each species were produced to reduce the impact of random factors on the experiment results. The objective of this work was to adapt the experiment according to GOST 31574—2012 «Dental polymer restorative materials. Technical requirements. Test methods.» adjusted for the technological capability of sample preparation. The weight method was used to assess the solubility of the test samples. Results. The sample thickness and dry heat oven drying temperature have a huge impact on the presence of residual water in the molecular matrix bonds, and, therefore, on the water solubility parameters. Water solubility and water absorption values were obtained for materials at holding temperature of 36.6°C and 70°C.