Soft lining materials in denture relining: Biological, mechanical, and clinical perspectives

Introduction. Loose-fitting dentures are a common clinical problem that compromises patient comfort, function, and prosthesis stability, primarily due to residual ridge resorption, systemic conditions, and excessive occlusal loading. Residual ridge resorption is a chronic and progressive process that reduces the quantity and quality of supporting tissues, particularly affecting removable dentures. Relining and rebasing procedures are widely used to restore denture adaptation, retention, and stability without fabricating a new prosthesis. Application of soft lining materials has gained clinical importance, especially in elderly patients with thin, sensitive, or traumatized oral mucosa. 

Material and method. Soft liners are classified into short-term materials, commonly referred to as tissue conditioners, and long-term soft liners. Tissue conditioners are viscoelastic materials used temporarily to promote mucosal healing, improve denture fit, and serve as functional impression materials. Long-term soft liners, including plasticized methacrylates and silicone-based materials, are indicated for patients with chronic mucosal discomfort, severe ridge resorption, or anatomical limitations.

Result and discussion. Silicone-based soft liners demonstrate superior long-term elasticity, dimensional stability, and biocompatibility compared with acrylic-based liners. Clinical outcomes of denture relining depend on appropriate material selection, handling protocols, and bonding quality between the liner and denture base. Silicone soft liners, particularly autopolymerizing types, are favoured due to their sustained resilience and minimal tissue irritation. Overall, soft liners play a significant role in reducing mucosal trauma, improving stress distribution, and enhancing denture retention. Proper clinical indication and material selection are essential to achieve optimal long-term therapeutic outcomes in removable prosthodontics.