Removable dentures aim to improve masticatory function, esthetics and phonetics. Different materials have been used as denture base materials but poly(methyl methacrylate) (PMMA) is most frequently used in most countries. Surface related properties of denture base materials (roughness, surface free energy, wettability, hydrophobicity, etc.) are of clinical importance since they affect plaque accumulation and staining. Surface roughness specifically influences the adhesion and retention of Candida Albicaans, which has a particular importance in denture-induced stomatitis pathogenesis. Bacterial plaque retention directly affects oral hygiene even if the patient achieves an appropriate cleaning of the denture. Ideally, denture base materials should be smooth so plaque adherence is reduced or even avoided. Test specimens of four heat polymerized materials were obtained by a classical press-pack dough molding technique of 1.5 mm thick wax-plate flasked in class III Moldano followed by the recommended polymerization regime. One of the materials was processed through a fast polymerization cycle. Injection-type materials were automatically produced using a dedicated injection unit. All plates were sectioned in 10 mm x 10 mm samples. No finishing protocol was applied. The selected specimens were examined under field emission scanning electron microscope (SEM). A large variation of surface topography was recorded between materials. There were visual differences between the four heat polymerized resins but also between the two injection-type materials. Surface topography was also influenced by the polymerization regime. Within the limitations of our study, we found that surface topography is influenced by the chemical composition of each material, the heat cure cycle and the processing method.
Comparative evaluation of the effect of denture cleansers on the surface topography of denture base materials: An in-vitro study