Long-term Viscoelasticity of Soft Lining Materials

Because soft lining materials are usually applied as short-term tissue conditioning or temporary lining, it isn't shown how long their elasticity and viscosity are kept. Now we have developed a new soft lining resin GC Tissue Conditioner (GC, Japan) with coating material but without phthalate plasticizer. Objective: The aim of this study was to evaluate GC Tissue conditioner compared with the conventional products by researching their long-term viscoelasticity. Methods: The soft relining materials used in this study were Tissue Conditioner (GC: TC and TC without coating), Softliner (GC: SL), Visco-gel (Dentsply: VG), Coe Soft (GC America: CS) and Coe Comfort (GC America: CC). All specimens were prepared according to the manufacturer's instructions. Those materials were performed 5 seconds and 30 seconds penetration test after 1 day and 28 days according to ISO 10139-2 (n=3) with Texture Analyser TA-XT2 (Stable Micro Systems Ltd.). The percentage difference (D) indicates the change of elastic property, the high D value means the decrease of elasticity. The penetration ratio (R) shows viscous property, the change of R value means that of viscosity. The data was analyzed by one-way ANOVA and Sheffe's F test (p<0.05). Results: Mean D and R values were shown below. Same superscript means no significant different. The mean D values of TC, TC without coating and VG were significant lower than those of other materials. The mean R values of SL, CS and CC changed significantly (**: p<0.01) after 28 days. Conclusion: These results suggested that TC, TC without coating and VG had the stable viscoelasticity for a long term.