## 1 Introduction
The molding process for Vertex ThermoSens involves an injection technique, which can be performed using automatic or manual injection machines [28; 29]. The inherent flexibility of these thermoplastic denture base materials makes them particularly suitable for removable partial dentures, producing durable and comfortable appliances [30]. While polyamide materials boast robust mechanical attributes, there is potential for enhancing their texture by modifying the technological parameters of their injection process [31; 32]. This altered surface must also be able to withstand impacts that might escalate roughness or compromise material quality [33]. Achieving these objectives could lead to an improved material surface that resists microbial adhesion and retains its structural integrity. This deduction supports the notion that Surface 1 absorbed many of the gases, thereby fostering the creation of numerous pores [34; 35]. Consequently, it can be inferred that Surface 1 predominantly absorbs the artificial saliva, which corresponds to the lower side of the casting or the side that encounters the oral mucosa. This scenario is undesirable due to its potential to facilitate contamination of the polymer with pathogenic microorganisms and the subsequent development of colonies [36; 37]. Thermoplastic resins offer numerous advantages compared to traditional powder or liquid resin systems. These include elevated flexural and impact strength, remarkable flexibility, transparency, significant resistance to creep and fatigue, exceptional wear properties, and solvent resistance [38]. They also exhibit low water absorption, minimal residual monomer content, limited porosity, reduced accumulation of biological materials, and diminished odor and staining [39]. Additionally, they demonstrate heightened dimensional and color stability. With a metal-free microcrystalline structure, finishing and polishing processes are simplified, akin to acrylic resins [40]. Their flexibility reduces stress transmission to adjacent teeth and surrounding tissues, thus lowering the risk of trauma [41]. Moreover, their esthetic appearance closely resembles oral tissues, eliminating the need for the metal claps commonly used in traditional metallic partial dentures [42]. Notably, Vertex ThermoSens exhibits a lower flexural modulus and a higher flexural strength compared to conventional denture base materials after a year of water storage [43]. Water absorption, a characteristic of dental materials, causes changes in size and weight [44]. Acrylic polymers tend to absorb water, gradually expanding over time. This expansion occurs in three dimensions and is influenced by the duration of water immersion until equilibrium is reached [45]. However, the equilibrium water content must stay below 32 \(\upmu\)g/mm\({}^{3}\). Water absorption can release internal stresses developed during manufacturing [46], potentially altering the shape of removable dentures [34]. Frequent wetting and drying should be avoided to prevent material aging and deformation in prosthetic restorations [47]. As dental resin dries, it expels water, causing polymer chains to revert to their original state [48]. Rehydration leads to chain expansion, creating minor fluctuations that can result in microcracks and, under mechanical stress, fractures in removable dentures. Saliva absorption prompts linear expansion, with levels assessed through specific laboratory tests according to ISO standards [49]. Several significant drawbacks associated with polyamide dentures include the propensity for plaque accumulation and substantial alveolar bone resorption in dedentulous regions. These issues stem from the absence of a conventional removable partial denture design, which is a primary factor contributing to the limited duration of oral use for polyamide dentures [50]. Plaque buildup poses a concern for oral hygiene and can lead to various dental problems, while the high degree of alveolar bone resorption in areas lacking teeth compromises the structural integrity of the denture's foundation.