2025 Volume 88 Issue 1 Pages 12-18
静脈内鎮静法下で歯科治療を行うことで，安全かつ快適に歯科治療を行うことが可能となる一方で局所麻酔による疼痛は，体動などの有害事象をもたらす．静脈内鎮静法下で情動がコントロールされた状況では，局所麻酔による疼痛のうち，精神的疼痛は軽減されるが，痛覚伝導路を介した疼痛は生じる．疼痛刺激は，鎮静深度を浅くさせ，体動や不穏・興奮，不快な記憶などの有害事象を生じさせる．そこで今回，局所麻酔針刺入前の表面麻酔薬使用が，局所麻酔時の鎮静深度・効果におよぼす影響について臨床統計学的検討を行った．表面麻酔薬使用により，刺入時の疼痛が緩和され，鎮静深度が浅くなるのを抑止でき，体動の抑制にも効果的であった．術中の不快な記憶に関しては，健忘効果によりほとんどの症例で記憶はなかった．しかし表面麻酔薬非使用群において鎮静深度が浅くなるのを抑止できることから，不快な記憶を残さないためには，表面麻酔薬の使用は効果的であると考えられた．そして知的能力障害者や血管迷走神経反射の既往を有する患者など，局所麻酔針刺入の痛みにより，健常者よりもより有害な事象を惹起すると考えられる患者に対してより有用であると考えられた．
Mental pain is reduced under emotion-controlled conditions with intravenous sedation, whereas regional anesthesia induces pain through the pain conduction pathway. Eruptive pain decreases the depth of sedation and can cause adverse events that interfere with safe and comfortable dental treatment. To provide safer and more comfortable dental treatment under intravenous sedation, we conducted a clinical and statistical study on how the use of topical anesthetic before local anesthetic needle insertion affects the depth and efficacy of sedation during local anesthesia. Our results suggest that the use of topical anesthetics reduces pain during needle insertion, suppresses the depth of sedation, and is effective in suppressing body movements caused by painful stimuli. However, unpleasant memories are rarely produced with or without the use of topical anesthetics because of the strong amnesic effect of intravenous sedatives and the reduction of mental pain. However, electroencephalogram monitored values were significantly elevated in the group that did not receive topical anesthetics, suggesting that their use may be effective, considering the possibility of unpleasant memories. These results suggest that the use of topical anesthetics in combination with emotional control by intravenous sedation may provide safer and more comfortable dental treatments under intravenous sedation than current methods. In the future, this strategy is expected to be more effective for patients who may experience more adverse events owing to the pain of the local anesthetic needle insertion, such as those with cognitive disabilities or those with a history of vasovagal reflexes. Shika Igaku (J Osaka Odontol Soc) 2025; Mar; 88(1): 12-18.
