唾液で汚染されたコンポジットレジン修復物の辺縁部および内部適合に及ぼす除染方法の影響

Effect of decontamination procedures on marginal and internal adaptation in saliva-contaminated composite resin restorations.

抄録

本研究の目的は，象牙質の自然唾液汚染がコンポジットレジン修復物の適応に及ぼす影響と，様々な除染方法の有効性を評価することである．120名のヒト臼歯および小臼歯を無作為に6群（n = 20）に分けた．標準化した象牙質窩洞を調製し，2 段階のエッチングとリンスによる接着を含む 6 種類の表面処理のうち 1 つを行い，コンポジットレジンで修復した．1：象牙質エッチング，接着剤塗布，光照射（コントロール），2：象牙質エッチング，唾液汚染，風乾，接着剤塗布，光照射，3：象牙質エッチング，唾液汚染，水洗，風乾，接着剤塗布，光照射，4：象牙質エッチング，唾液汚染，水洗，光照射（コントロール），光照射（ライトキュアリング）．4、デンチンエッチング、接着剤塗布、光硬化、唾液汚染、空気乾燥、5、デンチンエッチング、接着剤塗布、光硬化、唾液汚染、水洗、空気乾燥、6、デンチンエッチング、接着剤塗布、光硬化、唾液汚染、水洗、空気乾燥、接着剤再塗布のいずれか。適応度は，上面および深さ0.5mmと1.0mmにおいて，剥離縁の長さを測定し，窩洞周囲に対する割合（%DM）を算出することにより評価した．内部適合は，最大マージンギャップ（MMG）の幅を測定することにより評価した．唾液の混入により，適応度の低下が認められた．1群は上面で最も満足のいく適応を示したが，4群と5群はすべての面で%DMが最も高く，MMGが最も大きかった（P < 0.05）．第2，3，6群の%DMおよびMMG値は，第1群または各群の値と有意差はなかった．接着剤塗布後に唾液が混入した場合（第4，5群），辺縁部および内部の適応度が低下した．接着剤の再塗布により適応度が回復したことは，6群の%DMおよびMMGの値から明らかである．

The aim of the present study was to evaluate the effect of natural saliva contamination of dentin on the adaptation of composite resin restorations as well as the efficacy of various decontamination techniques. A total of 120 human molars and premolars were randomly distributed into 6 groups (n = 20). Standardized dentin cavities were prepared and restored with composite resin after 1 of 6 different surface treatments, which included a 2-step etch-and-rinse adhesive: 1, dentin etching, adhesive application following the manufacturer's instructions (control), light curing; 2, dentin etching, saliva contamination, air drying, adhesive application, light curing; 3, dentin etching, saliva contamination, water rinsing, air drying, adhesive application, light curing; 4, dentin etching, adhesive application, light curing, saliva contamination, air drying; 5, dentin etching, adhesive application, light curing, saliva contamination, water rinsing, air drying; or 6, dentin etching, adhesive application, light curing, saliva contamination, water rinsing, air drying, adhesive reapplication. The adaptation was evaluated at the top surface and at depths of 0.5 and 1.0 mm by measuring the length of the debonded margin and calculating its percentage relative to the cavity perimeter (%DM). The internal adaptation was evaluated by measuring the width of the maximum marginal gap (MMG). Inferior adaptation was observed after saliva contamination took place. Group 1 presented the most satisfactory adaptation at the top surface, whereas groups 4 and 5 had the highest %DM and greatest MMG at all surfaces (P < 0.05). The %DM and MMG values in groups 2, 3, and 6 were not significantly different from those of group 1 or each other. Saliva contamination after adhesive application (groups 4 and 5) resulted in deterioration of marginal and internal adaptation. Reapplication of the adhesive restored adaptation, as evidenced by the %DM and MMG values in group 6.