Effect of Disinfection on the Surface Roughness of Dental Casts Retrieved from Addition Silicone Impressions

Abstract

Background and aim: Changes in the physical properties of casts retrieved from disinfected impressions are a common problem in the fabrication of dental prostheses. However, there are limited data available about the effect of disinfecting solutions on the surface roughness of casts. This study aimed to assess the surface roughness of casts retrieved from addition silicone impressions disinfected by immersion in three different disinfectants for 5 and 30 minutes. Materials and methods: This in-vitro experimental study was conducted on 49 casts in 7 groups (n=7). A standard stainless steel die was used according to ANSI/ADA specification no. 25, and impressions were made using a low-viscosity addition silicone impression material. The impressions were disinfected by immersion in 1% sodium hypochlorite (NaOCl), 2.4% glutaraldehyde, or 5% povidone-iodine for 5 and 30 minutes. All impressions were poured with type IV dental stone, and their surface roughness (Ra) was measured using a digital hand-held roughness tester. Data were analyzed using two-way analysis of variance (ANOVA) and Tukey's test. Results: One-way ANOVA showed a statistically significant difference between the control group and the other 6 groups (P=0.004). 1% NaOCl/5 minutes was the only group which presented a different result from the control group (P=0.012). Two-way ANOVA showed that over time, the surface roughness of casts retrieved from silicone impressions disinfected by immersion in a disinfectant decreased (P=0.002), but no significant difference was noted between the disinfectant agents (P=0.243). Conclusion:The type of the disinfectant had no significant effect on surface roughness, although an increased duration of disinfection decreased the surface roughness of casts.

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“…Chemically disinfected samples investigation. This result is consistent with the findings from other studies [29]. Some research suggests that disinfectant treatments alter the surface chemistry of an impression material, perhaps resulting in a change in hydrophilicity and surface roughness.…”

Evaluation of Bacterial Contamination in Clinical Environment of Sari Dental School in 2018

“…(12) Anjumn et al investigated the contamination of laptop keyboards in clinical departments of the Faculty of Dentistry. (13,14) more contaminated than the units of the periodontics department. (5) The duration of treatment in restorative dentistry department and use of highspeed turbines with cooling water spray may justify this result.…”

Determination of Surface Roughness and Accuracy of Alginate Impression Material Disinfected by Immersion

“…Table (1) presents the descriptive statistics and figure (7) for the alcohol and povidone iodine groups. The mean values of alcohol specimens were decreased after immersion while increased in a povidoneiodine group after immersion.…”

“…American Dental Association for control guidelines infection advised immersion disinfection of hydrocolloid irreversible impression because it was more reliable and effective. Various solutions, such as sodium hypochlorite, formaldehyde, synthetic phenol, iodine, and alcohol, are applied to the chemical disinfection of dental material (7) . The seen changes in the dimensional stability and surface chemistry of the impression depend on the type of disinfectant used.…”

“…Immersion of impression in disinfectant solutions for a longer time causes changes in the impression, transferred to the cast (13) . Changes in the properties of gypsum cast, containing dimensional stability, hardness, surface detail reproduction and roughness will affect the accuracy of complete restoration after increasing the time of immersion of an impression (7) . This study was designed to access the dimensional accuracy due to imbibition phenomena and surface roughness of alginate material immersed in two different chemical disinfectant solutions.…”