Effect of denture cleansers on color stability and surface roughness of denture base acrylic resin.

Background: Color stability of acrylic resin is one of the most important feature for denture wearers. Many patients use detergent solutions to remove denture stains. The purpose of this study was to evaluate color stability and surface roughness of two common acrylic resins in different detergent and tea solutions. Materials and Methods: 112 acrylic resin blocks of Meliodent and Acropars (each 56 blocks) were divided into seven groups of different treatment: 1% sodium hypochlorite for 10 min a day for 1 month (H10m), 1% sodium hypochlorite for 8 hours a day for 1 week (H&h), Correga tabs solution for 8 hours a day for 1 month (C&H), tea bag for 2 hours a day for 1 month (T2 h), tea bag for 2 hours a day then 10 min in 1% sodium hypochlorite for 1 month (T-H), tea bag for 2 hours then 8 hours in the Correga tab solution a day for 1 month (T-C), and finally distilled water for 1 month as a control group (con). After specimen's treatment, color (CIE Lab) and surface roughness (Ra, μm) of samples were measured. The results were analyzed by analysis of variance (ANOVA), followed by Tukey’s HSD and Dunnett T3. Results: Group T2h exhibited a significant (P<0.05) color change and control specimens exhibited the lowest color change. Sodium hypochlorite caused a significant (P<0.05) color change in the Acropars group in comparison with the Meliodent group. In the Correga tab solution the difference was not significant (P=0.155). There was a significant (P<0.05) color change in the T-H treatment. The Acropars and Meliodent acrylic resin did not a show significant difference in surface roughness after different treatments. Conclusion: Sodium hypochlorite 1% for 10 minutes a day in a month is the recommended hygiene protocol. The color stability of acryl is brand-type dependent but surface roughness is not.

The microbiology of the peri-implant sulcus following successful implantation of oral prosthetic treatments.

Background: Oral implants are widely used in partially and fully edentulous patients; however, the integration of an implant can be endangered by factors such as intraoral bacteria or inflammatory reactions. The purpose of this study was to evaluate the microbial flora present in the sulcus around dental implants and to assess the relationship between gingival health and microbial flora present. Materials and Methods: Twenty patients who had received oral implants with no complications were followed for a period of 9 months. Assessment of probing depth, the presence of bleeding on probing and microbial sampling from the peri-implant sulcus were performed at three different time points- 4 weeks after surgery, 1 month and 6 months after loading. The samples were taken by paper points and transferred to the microbiology lab in thioglyocolate cultures. In order to do a colony count and isolate the aerobic capnophilic and anerobic bacteria the samples were cultured and incubated on laboratory media. The colonies were also identified using various diagnostic tests. Alterations in the presence of various bacterial species over time and gum health were tested using analysis of variance (ANOVA) with Tukey's test post hoc. Results: The average pocket depth for each patient ranged from 1.37 ±0.39 mm to 2.55 ± 0.72 mm. The bacteria isolated from the cultured samples included aerobic, facultative anerobic, obligate anerobic and capnophilic bacteria. Conclusion: The anerobic conditions created in the peri-implant sulcus might with time enhance the number of anerobic bacteria present following dental implant loading.