長時間の歯科漂白がエナメル質表面への接着力に及ぼす影響

Influence of Prolonged Dental Bleaching on the Adhesive Bond Strength to Enamel Surfaces.

• Juliana C P Baia
• Roberta P Oliveira
• Mara E S Ribeiro
• Rafael R Lima
• Sandro C Loretto
• Mário H Silva E Souza Junior

抄録

本研究の目的は，4%過酸化水素(PH4)を用いたエナメル質に対する接着強度(マイクロシェア)に及ぼす長時間の漂白前およびポストレストレーションの影響を評価することであった．漂白後試験片の評価では，漂白後にコンポジットシリンダーを組み立て，漂白前試験片では組み立てを行った．したがって，漂白後試験片では，60本のウシ歯を以下のように無作為に割り付けた．G1：コントロール，G2：接着強度（BS）試験前の14日間の漂白，G3：21日間，G4：28日間。漂白前の試験片では，180本のウシ歯を以下のように無作為に割り付けた．G1：コントロール；G5：14日間の漂白，人工唾液中での保存（BS試験前24時間）；G6：14日間の漂白，ASの保存（BS試験前7日間）；G7：21日間の漂白，ASの保存（BS試験前24時間）；G8：21日間の漂白，ASの保存（BS試験前7日間）；G9：28日間の漂白，ASの保存（BS試験前24時間）；およびG10：28日間の漂白，ASの保存（BS試験前7日間）。結果はANOVA一方向(postrestoration bleaching)および二方向(prerestoration bleaching)とTukeyのポストホック検定( ≤ 0.05)に提出した。漂白後の漂白では、時間間の統計的差は見られなかった。しかし、漂白群を対照群(G1)と比較すると、表現的な差が認められた( ≤ 0.0001)。また、修復前漂白については、G1と比較して、G6を除く全ての実験群で統計的に差が認められ（≤0.05）、G5とG6では統計的に差が認められた（≤0.01）。また、G7とG8、G9とG10については、ASの保存時間にかかわらず、有意差は認められなかった( ≥0.05)。PH4による長時間の漂白は、漂白の瞬間（修復後漂白、修復前漂白）にかかわらず、耐付着性を低下させると結論づけられた。

The objective of this in vitro study was to assess the influence of prolonged bleaching pre- and postrestoration on the bond strength (microshear) to enamel using 4% hydrogen peroxide (PH4). In the postrestorative bleached specimens evaluation, the composite cylinders were assembled after bleaching, while in the prebleached specimens, the cylinders were assembled before. Therefore, in the postbleached specimens, 60 bovine teeth were randomly assigned as follows: G1: control; G2: 14 days bleaching before bond strength (BS) testing; G3: 21 days; and G4: 28 days. In prebleached specimens, 180 bovine teeth were randomly assigned as follows: G1: control; G5: 14 days bleaching, storage in artificial saliva (AS) for 24 h before BS testing; G6: 14 days beaching, AS storage for 7 days before BS testing; G7: 21 days bleaching, AS storage for 24  h before BS testing; G8: 21 days bleaching, AS storage for 7 days before BS testing; G9: 28 days bleaching, AS storage for 24 hours before BS testing; and G10 : 28 days bleaching, AS storage for 7 days before BS testing. The results were submitted to ANOVA one-way (postrestoration bleaching) and two-way (prerestoration bleaching) and Tukey's post hoc test ( ≤ 0.05). In the postrestoration bleaching, no statistical difference between times was found. However, when bleached groups were compared to the control (G1), an expressive difference was detected ( ≤ 0.0001). For prerestoration bleaching, all experimental groups were statistically different from G1 ( ≤ 0.05), except G6 ( ≥ 0.01), and for G5 and G6, statistical differences were found ( ≤ 0.01). There were no significant differences between G7 and G8 and between G9 and G10, regardless of the AS storage times ( ≥ 0.05). It was concluded that prolonged bleaching with PH4 decreased adhesion resistance regardless of the moment of the bleaching (post- and prerestoration bleaching).

Copyright © 2020 Juliana C. P. Baia et al.