Comparative Evaluation of Effect of Various Denture Hygiene Methods on Optical Density and Color Stability of Commercially Available Silicone Relining Materials: An In vitro Study

A BSTRACT Background: Denture hygiene methods like mechanical and/or chemical cleaning are commonly used for maintaining denture in clean and hygienic state. These methods influence the optical properties of commercially available silicone relining materials. Aim of the Study: The present study was performed to assess the effect of denture hygiene methods on optical properties, namely optical density (OD) and color stability (CIELAB) of commercially available silicone (heat and self-polymerizing) relining materials. Materials and Methods: The present study was an in vitro study undertaken at the Department of Prosthodontics and Crown and Bridge of the institution and a research organization affiliated to the same. Forty samples consisting of both self-polymerized ( n = 20) and heat-polymerized ( n = 20) silicone relining materials as per ISO 10139:1-2018 standard for evaluating optical property were categorized into eight distinct groups (Groups S1–S4 and H1–H4), with four groups assigned each to self-polymerized (Group S) and heat-polymerized (Group H), respectively. Each group further comprised five specimens each. Four subgroups were no cleaning/control group (S1/H1), chemical cleaning group (S2/H2), denture brush cleaning group (S3/H4), and electric toothbrush cleaning group (S4/H4). Specimens were assessed for a duration of 6 months to study the effect of simulated denture hygiene practices of mechanical brushing, electric brushing, and chemical methods on their optical properties, namely OD and color stability at baseline and postintervention using a multimode plate reader and digital spectrophotometer, respectively. SPSS version 23.0 (IBM, Chicago, Illinois, USA), was used to apply statistics to the data. The data were analyzed using unpaired and paired t -test, analysis of variance, and multivariate regression analysis. The level of significance was set at P < 0.05. Results: The findings of the study revealed significant variations in optical properties (“OD” and “CIELAB” values) for both self-polymerized and heat-polymerized silicone soft relining materials after pre- and postintervention comparison between the three interventions. Conclusion: The color shift was clinically acceptable for all modes of denture hygiene method for heat-polymerized silicone soft relining material.