軟質義歯用ライナーの水中への長時間浸漬が粘弾性特性に及ぼす影響

Effect of long-time immersion of soft denture liners in water on viscoelastic properties.

抄録

本研究の目的は，軟質義歯用ライナーの37℃水中への長時間浸漬が粘弾性特性に及ぼす影響について検討することである．シリコーン系軟質義歯ライナー6種とアクリル樹脂系軟質義歯ライナー2種を選定した．円柱状の試験片を37℃の蒸留水中に6ヶ月間保存した．粘弾性特性は，クリープメータを用いて，瞬時および遅延弾性変位，粘性流動，残留変位を測定し，2元配置分散分析およびTukeyの比較（α＝0.05）で解析した．粘弾性特性およびその時間依存性変化については、検討した材料ごとに異なる。シリコーン系ライナー6種のうち3種の粘弾性特性は6ヶ月間浸漬しても有意な変化は認められなかったが，アクリル樹脂系ライナー2種の粘弾性特性は浸漬時間の延長に伴って有意に変化した．しかし，2枚のアクリル樹脂製ライナーの6ヶ月間浸漬時の初期瞬間弾性変位と遅延弾性変位の和は10％以下の変化であり，臨床的に十分な弾性性能を示すと思われる．

Aim of this study was to investigate the effect of long-time immersion of soft denture liners in 37°C water on viscoelastic properties. Six silicone-based and two acrylic resin-based soft denture liners were selected. Cylindrical specimens were stored in distilled water at 37°C for 6 months. Viscoelastic properties, which were instantaneous and delayed elastic displacements, viscous flow, and residual displacement, were determined using a creep meter, and analyzed with 2-way analysis of variance and Tukey's comparison (α=0.05). Viscoelastic properties and their time-dependent changes were varied among materials examined. The observed viscoelastic properties of three from six silicone-based liners did not significantly change after 6-month immersion, but those of two acrylic resin-based liners significantly changed with the increase of immersion time. However, the sum of initial instantaneous elastic displacement and delayed elastic displacement of two acrylic resin-based liners during 6-month immersion changed less than 10%, which might indicate clinically sufficient elastic performance.