A simple method for obtaining a uniform thickness for long-term soft denture linings.

The thickness of long-term soft denture linings influences both their compliance and durability. Increasing the thickness of the lining material increases its perceived softness but makes the restoration more likely to fail through weakening of the acrylic resin denture base. Such effects have led to broad recommendations as to an appropriate thickness, advice that assumes a constant thickness of the lining material within the same denture. Several procedures used to produce such a constant thickness have been described. The necessary spacer is produced by manually adapting materials in their plastic state to the cast. Such procedures are liable to distortion and variation in spacer thickness and can be considered unreliable. This article describes a method for obtaining a uniform thickness of soft denture lining through the use of a vacuum-formed, thermoplastic blank as a spacer. The method is simple, applicable to all ridge forms, and reliably results in a soft lining of a known, uniform thickness. The method can be applied to long-term soft linings placed in both old and newly fabricated dentures. The spacer can be modified to allow variations in the prescribed extension of the soft lining within the denture base.