侵食を伴う象牙質知覚過敏症の治療における活性物質の消炎効果

Obliterating potential of active products for dentin hypersensitivity treatment under an erosive challenge.

抄録

目的:

象牙質の透水性コンダクタンス（Lp）に対する5種類の減感作剤の効果を比較するとともに、レーザー走査型共焦点顕微鏡（LSCM）を用いて象牙質表面の分析を行う。

OBJECTIVES: To compare the effect of 5 desensitizing agents on the hydraulic conductance (Lp) of dentin and to analyze its surface under a Laser Scanning Confocal Microscope (LSCM) before and after an erosive challenge.

方法:

Lpは，スミア層がある状態（pMin），15秒間の酸エッチング後（pMax），減感剤処理後（pTreat），1分間の侵食チャレンジ（6％クエン酸）後（pEro）という順序で分析した。健全なヒト第三大臼歯から厚さ1.0±0.2mmの象牙質円板を50枚用意し，無作為に5群（n=10）に分けた。FG-フッ化物ゲル（コントロール），SA-Sensiactive，PR-Sensitive Pro-Relief，NP-Desensibilize Nano-P，EV-Enamel Pro Varnish。データは二元配置のANOVAとTukey検定で解析した（α＜0.05）。さらに，レーザー走査型共焦点顕微鏡（LSCM）とエネルギー分散型X線分光法（EDS）で試料を分析した。

METHODS: Lp was analyzed in the following sequence: in the presence of smear layer (pMin), after a 15-second acid etching (pMax), after treatment with a desensitizing agent (pTreat) and after a 1-minute erosive challenge (6% citric acid - pEro). Fifty 1.0 ± 0.2 mm-thick dentin disks were prepared from sound human third molars and were randomly distributed into 5 groups (n = 10): FG-Fluoride gel (control), SA-Sensiactive, PR-Sensitive Pro-Relief, NP-Desensibilize Nano-P and EV-Enamel Pro Varnish. Data were analyzed by two-way ANOVA and Tukey tests (α<0.05). Additional specimens were analyzed under a Laser Scanning Confocal Microscope (LSCM) and by Energy Dispersive X-ray Spectroscopy (EDS).

結果:

FGとEVを除くすべての材料でLpがある程度減少した。侵食を受けても，SAは処理後のLpを効果的に維持できる唯一の材料であったが，他の製品は侵食を受けたときの抵抗が低かった。LSCMでは，SAとNPは象牙細管を破壊する効果が高く，侵食に対しても高い抵抗性を示した。EDS分析では，Ca，O，P，Si，Na，Sが検出された。

RESULTS: All materials reduced the Lp in some extent, except for FG and EV. After the erosive challenge, SA was the only material effectively able to keep the same Lp of the post-treatment phase, while the other products showed lower resistance upon an erosive challenge. Under the LSCM, the SA and NP materials were more effective to obliterate the opened dentin tubules and demonstrated higher resistance upon an erosive challenge. The EDS analysis evidenced levels of Ca, O, P, Si, Na and S.

結論:

シュウ酸カリウムを含む製品は、侵食前と侵食後の象牙質サンプルのLpを減少させるのに最も効果的であった。LSCMでは，シュウ酸カリウムやハイドロキシアパタイト結晶を含む製品が，侵食後の象牙細管を閉塞しているように見えた。

CONCLUSIONS: Product containing potassium oxalate was the most effective in reducing Lp of dentin samples before and after an erosive challenge. Under a LSCM, products containing potassium oxalate or hydroxyapatite crystals seemed to be occluding the dentin tubules after an erosive challenge.