Abstract:

A variety of thermoplastic materials, including “ThermoSens”, a nylon-based denture base material, can be used in the fabrication of removable partial dentures. Assessing the physical properties of these materials is crucial, as they influence not only the aesthetics but also the longevity and functionality of the dentures. Thermoplastic polyamides, known as nylons, represent a key group of flexible materials employed for partially edentulous patients with removable dentures.
Aim. The aim of this study was to evaluate the impact of ten distinct cleaning methods on the water absorption of “ThermoSens”, using the gravimetric method.
Materials and methods. The study involved 50 standardized “ThermoSens” test specimens divided into ten groups, subjected to varied cleaning protocols including Corega and Protefix tablets, soft toothbrush with toothpaste or soap, and no cleaning (control). Cleaning frequency and duration differed across groups, with all specimens stored in artificial saliva at 37°C for 24 hours. Water absorption was measured using a KERN ALJ 120-4 analytical scale, calculated as a percentage of initial mass, adhering to ISO 62 and ASTM D570 standards. Statistical analysis was performed using ANOVA (p=0.038) to assess differences between groups.
Results. The results indicate that cleaning methods significantly affect “ThermoSens” water absorption, with Groups 3 and 9 (using Corega tablets and toothbrush with toothpaste, respectively, three times weekly) showing the lowest uptake.
Conclusion. The hydrophobic nature of nylon 12 in “ThermoSens”, with lower amide group density, contributes to its water resistance, supporting its use in dentures, though further research is needed to refine cleaning protocols.

Keywords: denture base material, nylon, water absorption, polyamide, “ThermoSens”, gravimetric method