A polyvinylsiloxane denture soft lining material.

A new denture soft lining material based on a polyvinylsiloxane system, similar to that used in addition-curing silicone impression materials, has recently been developed. The purpose of the work reported here was to compare certain key properties of the new material with those of other commercially available materials. Setting characteristics, resistance to penetration, elastic properties, water absorption, peel strength and contact angle with water were determined for five materials including the new product. In addition, the change in properties following water storage were determined. In many respects the properties of the new material were noted to be similar to those of a heat-cured silicone product. It is initially elastic and of "medium" softness as defined by ISO 10139-2. It was the only product which did not lose weight on storage in water and over 90 days of storage it gave only a small change in compliance as measured by surface penetration. Bond strength of the new material to an acrylic denture base appears only moderate. However, failure was cohesive within the soft material with no peeling, suggesting that peeling is unlikely to occur in practice. The affinity between the surface of the material and water, as determined by contact angle, is significantly better than for other silicone products. The properties of the polyvinylsiloxane denture soft lining material are in many respects similar to those of other silicone soft lining materials. However, the efficacy of the adhesive which prevents peeling combined with a convenient packaging, proportioning and mixing system suggests that the material may offer some advantages which warrant its clinical evaluation.