Color Stability and Hardness of Permanent Silicone Soft Denture Liners Following Storage in Artificial Saliva: An In Vitro Study

Relining materials are routinely subjected to saliva components, the oral cavity's temperature, and influences related to patients' behaviors, including food colorings, medications, tobacco, and denture cleansers.The lining materials progressively harden because of a three-part sequence of events, including ethanol loss, water absorption, and plasticizer degradation, thereby restricting their utility.4 Water absorption and the extraction of elements such as plasticizers modify the mechanical and chemical properties of the material, leading to increased hardness and color alterations.5 Color stability is a critical clinical characteristic of all dental materials, with color alterations serving as markers of material aging or degradation.6 Color evaluations are conducted using a spectrophotometer.Spectrophotometry is an objective technique for evaluating color alteration by quantifying the light reflected from the material.A significant drawback of SLs is the challenge of maintaining their hygiene.Consequently, infection caused by Candida albicans may develop on the materials, resulting in denture IntroductIonThe clinical preference for detachable prosthetic replacements will continue to grow, notwithstanding the rising health consciousness among patients.The application of soft relining technologies in prosthetic therapy is noninvasive and cost-effective; it markedly enhances the quality of life for those needing dental reconstructions and increases their level of satisfaction.1 Soft lining materials for dentures create a resilient, padded interface between the rigid base of a denture and the oral mucosa.The capacity to attain the cushioning effect is associated with their resilience.The level of resilience is determined by the material's chemical makeup and the degree of soft lining thickness.They are employed to reline the tissue side of a detachable dental prosthesis with new base material, ensuring precise conformity to the denture foundation region.They are frequently recommended for patients who report that their dentures are loose, slipping, falling, or causing discomfort; however, at times, such prescriptions are unsuitable.The initial clinical application of softer denture liner materials was documented in 1943. 2 The utilization of soft liners (SLs) has gained popularity for enhancing comfort among denture users.The efficacy of detachable complete or partial dentures relies on esthetics, comfort, and functionality.Soft denture liners facilitate uniform functional load distribution across the denture-bearing region, thereby preventing localized stress concentration.3 However, their application is accompanied by various issues.Certain SLs exhibit instability in the oral cavity.Color instability may occur because of the solubility and deterioration of inherent dyes, along with the oxidation of carbon-carbon double bonds, resulting in the production of colored oxides and dehydration.