Journal of Dental Medicine

Statement of Problem:The surface topography of denture base material is an important factor for the adhesion of Candida albicans and other microorganisms.

Purpose: The aim of this study was to evaluate the adherence of Candida albicans to four types of denture base materials (Acropars acrylic resin, Meliodent acrylic resin, rough and smooth surfaces of Molloplast B).
Materials and Methods: Seven blocks of two types of acrylic resins and ten blocks of silicone with one rough and one smooth surface were made and incubated in a suspension of Candida albicans. After washing,the blocks were stained with acridine orange and examined under fluorescent microscope. For statistical analysis ANOVA and Duncan tests were used.

Results: It was observed that Candida adhesion to rough surfaces of acrylic resins and silicone was significantly more than polished surfaces of acrylic resins and smooth silicone (PO.0001). However, no
statistical significant difference was found between polished acrylic resins surfaces and smooth silicone.
Conclusion: Significant differences in the adherence of Candida to the surfaces of different denture base
materials are due to differences in surface topography, chemical, physical and hydrophobic properties so it is
recommended to minimize the roughness and irregularities of denture base.

  Background and Aims: Marginal fit is one of the key factors in the success of fixed restoration. The aim of this study was to evaluate the fitness of feldespatic crowns made from additional silicon impression and gypsum cast by CAD/CAM.

  Materials and Methods: 10 intact extracted upper premolar teeth were used for this experimental study. After preparation of the mounted teeth with radial shoulder finish line, 2 Vita Mark II feldespatic CAD/CAM machined crowns were fabricated for each tooth (one from scanning the additional silicone impression of the prepared tooth and the other one from the plaster model). Marginal gap of each crown was measured using SEM in two points on the mesial and 2 points on the buccal surface. Data were analyzed using Paired t-test with SPSS version 17 software (P<0.05).

  Results: The mean of marginal gaps in crowns fabricated from additional silicone and model plaster were (155.13±37.11) and (130.18±12.35), respectively. However, no significant difference emerged between marginal gaps of the two methods (P=0.055). Also, the mean of marginal gaps in crowns fabricated from additional silicone and model plaster was higher in mesial (157.82±44.41) compared to buccal (127.50±24.26) region (P=0.003).

  Conclusion: Marginal fit was not significantly differen ce between crown s made of the plaster casts and silicone molds and both methods showed the same results .