VISCOELASTIC PROPERTIES OF HARD AND SOFT DENTURE BASE RELINE MATERIALS

Background: Reline materials are integral part in management of patients wearing removal complete dentures. Objectives: The objective of this study was to assess and compare the viscoelastic properties of the permanent hard acrylic resin reline and silicone based soft liner materials. Materials and methods: Rectangular specimens of the hard reline (Acrostone, Dental & Medical Co, Egypt) and silicone liner (Molloplast B, Detax Karl Huber GmbH & Co., Karlsruhe, Germany) materials were fabricated according to the manufacturer's instructions of each material. The viscoelastic properties regarding (G \', G \'\' and tan ?) were measured using visco-elastometer under shear mode of deformation at a frequency of 1 Hz at 37°C. Results: The hard resin reline material showed higher statistically significant mean values (P<0.05) regarding the three measured parameters. However, both materials had tan ? values approaching zero. Conclusions: within the limitation of this study the following could be concluded: Both materials had cushioning effect and the ability to dissipate energy into heat. However, hard resin reline absorb more energy consequently, it reduces stress transmitted to alveolar mucosa more than that of silicone based soft liner. Key words, Viscoelastic, denture reline, hard and soft reline material.