Surface roughness of acrylic resins submitted to mechanical and chemical polishing

Abstract

Surface roughness is extremely important as it influences micro-organism accumulation and consequently oral health. The aim of the present study was to evaluate the influence of mechanical polishing (MP) and chemical polishing (CP) on surface roughness of four heat-cured denture base acrylic resins. Twenty sample discs were prepared for each of the following acrylic resins: Classico (CL), QC 20 (QC), Acron MC (AC) and Onda Cryl (ON). The first two are boiling cured resins and the latter two are microwave cured. After curing and deflasking, samples were ground and subdivided into two groups: MP, which received pumice slurry, chalk powder, soft brush and felt cone, at a bench vice; and CP, which received fluid specifically for chemical polisher. Surface roughness was measured using a Surf Corder SE 1700 rugosimeter. Data collected were statistically analysed by analysis of variance followed by Tukey's test. Surface roughness means in mum were: CL-MP: 0.0350; CL-CP: 0.2298; QC-MP: 0.0307; QC-CP: 0.1792; AC-MP: 0.0312; AC-CP: 0.2700; ON-MP: 0.0321; ON-CP: 0.2949. It can be concluded that MP produced significantly smoother surfaces than CP and that surface roughness because of MP was not influenced by acrylic resin type, whereas this was not true of CP.

Surface Roughness of Auto Polymerized Acrylic Resin According to Different Manipulation and Polishing Methods

“…Polishing techniques indeed influenced the Ra; mechanical polishing was superior to chemical polishing in this aspect (Table 2), as only the first one achieved surface roughness under 2.0 m, which is the value previously established as a threshold for surface roughness in these cases. 7 This is in accordance with Rahal et al, 8 who also found that the chemical polishing generated rougher surfaces than mechanical polishing. Zissis et al 9 did not polish the tested surfaces and found surface roughness between 3.4 and 7.6 m, higher than the values found in the current study.…”

An In vitro Comparative Evaluation of Disinfectants on Standard and Clinical Microbial Strains on Heat Cure Resins

“…Hence, few of the most commonly used disinfectants such as sodium hypochlorite; glutaraldehyde, chlorhexidine and sodium perborate [3,[15][16][17][25][26][27][28][29] were used in present study. The micro-organisms namely Streptococcus mutans and Candida albicans were studied since they are common commensals of oral cavity.…”

“…Studies done on various disinfectants, have shown that sodium perborate can be substituted with more effective disinfectants like sodium hypochlorite [3,[15][16][17][25][26][27][28][29].…”

“…Even though, sodium hypochlorite has proved to be the most effective disinfectant indicated from various studies by different researchers [3,[15][16][17][25][26][27][28][29], it is not popularly prescribed. Moreover, still extensive research and clinical trials comparing only sodium hypochlorite and sodium perborate are required to prove sodium hypochlorite as the most popular and commonly used disinfectant among denture wearing patients, thus rendering the near to best disinfectant so that prosthesis sterilization is performed even out of the dental office by the patient.…”

Influence of Energy Beverages on the Surface Texture of Glass Ionomer Restorative Materials

“…24 The surface roughness calculated between 0.5 and 10 µm is rough enough to retain the bacterial plaque and is clinically not acceptable. 25 Low pH results in loss of minerals adsorbed on the dental hard tissues, thus affecting the surface. 26,27 Surface roughness Ra parameter increases with time in different tested energy beverages, and it was highly significantly different in all glass ionomer restorative materials immersed with Code Red (p = 0.000), Red Bull (p = 0.000), and Power Horse (p = 0.000); the surface roughness values were measured using surface scanning interferometry.…”