6種類の義歯床用アクリルレジンの破壊強度の比較

Comparison of the fracture resistance of six denture base acrylic resins.

抄録

義歯床用レジンの破壊強度は大きな関心事であり，アクリルレジン義歯を強化するために多くのアプローチが用いられてきた．市販されている6種類の義歯床用アクリルレジン材料の耐破壊性を，衝撃試験と横強度試験により比較した．急速加熱重合レジン3種（QC 20、Meliodent、Trevalon）、高衝撃強度レジン2種（Trevalon Hi、Lucitone 199）、強化射出成型アクリルレジン（SR Ivocap plus）を試験に組み入れた。各樹脂から20個のアクリル樹脂試験片を作製した。衝撃強度試験には、10個のノッチ付き試験片をシャルピー型衝撃試験機で試験した。他の10個の試験片は横強度試験に用い、たわみと弾性率も測定し、万能試験機を用いた3点曲げ試験で評価した。衝撃試験値は、アクリル樹脂間で有意差を示した（F= 4.817 p = 0.0）。SRアイボキャップレジンが最も高い衝撃強さを示し、次いでトレバロンHi、ルシトン199の順であった。6種類のアクリル樹脂を比較したところ、横強度試験値は有意ではなかった（F= 1.705 p = 0.151）。高衝撃性レジンは義歯床の衝撃強度を高めるために推奨できる．破折の原因が機械的あるいは解剖学的なものであれば，強化アクリルレジンと従来のアクリルレジンは同程度の耐破折性を有する．

Fracture strength of denture base resins is of great concern, and many approaches have been used to strengthen acrylic resin dentures. Fracture resistance of six commercially available acrylic resin denture base materials were compared, through impact and transverse strength tests. Three rapid heat-polymerised resins (QC 20, Meliodent and Trevalon), two high-impact strength resins (Trevalon Hi and Lucitone 199) and a strengthened injection-moulded acrylic resin (SR Ivocap plus) were included in the study. Twenty acrylic resin test specimens were fabricated from each resin. For impact strength test, ten notched specimens were tested in a Charpy-type impact tester. The other ten specimens were used for transverse strength tests, deflection and modulus of elasticity values were also determined, which were assessed with three-point bending tests using an Universal Testing Machine. Impact test values showed significant differences among acrylic resins (F= 4.817 p = 0.0). SR Ivocap resin showed the highest impact strength values, followed by Trevalon Hi and Lucitone 199. The transverse strength test values were not significant when six acrylic resins were compared (F= 1.705 p = 0.151). High-impact resins can be recommended to increase the impact strength of denture base. If the cause of fracture is mechanical or anatomical, strengthened acrylic resins and conventional acrylic resins have similar fracture resistance.