Different Polymers for the Base of Removable Dentures? Part I: A Narrative Review of Mechanical and Physical Properties

Abstract

Even before considering their introduction into the mouth, the choice of materials for the optimization of the prosthesis depends on specific parameters such as their biocompatibility, solidity, resistance, and longevity. In the first part of this two-part review, we approach the various mechanical characteristics that affect this choice, which are closely related to the manufacturing process. Among the materials currently available, it is mainly polymers that are suitable for this use in this field. Historically, the most widely used polymer has been polymethyl methacrylate (PMMA), but more recently, polyamides (nylon) and polyether ether ketone (PEEK) have provided interesting advantages. The incorporation of certain molecules into these polymers will lead to modifications aimed at improving the mechanical properties of the prosthetic bases. In the second part of the review, the safety aspects of prostheses in the oral ecosystem (fragility of the undercuts of soft/hard tissues, neutral pH of saliva, and stability of the microbiota) are addressed. The microbial colonization of the prosthesis, in relation to the composition of the material used and its surface conditions (roughness, hydrophilicity), is of primary importance. Whatever the material and manufacturing process chosen, the coating or finishes dependent on the surface condition remain essential (polishing, non-stick coating) for limiting microbial colonization. The objective of this narrative review is to compile an inventory of the mechanical and physical properties as well as the clinical conditions likely to guide the choice between polymers for the base of removable prostheses.

Comparative Analysis of the Mechanical Properties and Biocompatibility between CAD/CAM and Conventional Polymers Applied in Prosthetic Dentistry

“…Possessing commendable mechanical properties, they can withstand temperatures ranging from 230 to 290 • C, with a modulus of elasticity of approximately 1490 MPa. Transparent and easily polished, polyesters offer versatility in dental applications [38].…”

“…Despite certain drawbacks, injection materials remain a preferred alternative, likely due to the precision and efficiency of the injection molding process [38], which results in positive material attributes and low residual monomer levels, expanding their applications in dental practice.…”

Microbial Adhesion to Different Thermoplastic Denture Base Materials in Kennedy Class I Partially Edentulous Patients

“…Various materials can be utilized to fabricate RPD, most commonly cobalt-chromium alloys and polymethyl methacrylate resin [ 6 ]. Polymethyl methacrylate (PMMA) is widely used for prosthetic dental applications such as denture bases, obturators, and temporary or provisional crowns [ 7 ].…”

Colonization of Candida Spp. In Patients Treated With Partial Dentures "Thermosens"

“…The quantity of Candida spp. isolated from swabs taken from the denture surface, the underlying oral mucosa can vary, and there is no consensus on the amount of colony-forming units per milliliter (CFU/mL) that lead to symptomatic DRS [18].…”