針照射、超音波照射、EDDY、Er:YAG、ダイオードレーザーによる未成熟歯の次亜塩素酸ナトリウムの歯根端押出しの比較

Comparison of apical extrusion of sodium hypochlorite in immature teeth after needle irrigation, ultrasonic irrigation, EDDY, Er:YAG, and diode lasers.

抄録

本研究は，針照射，超音波照射，EDDY，Er:YAG，ダイオードレーザーによる未成熟歯の次亜塩素酸ナトリウムの歯根端押出しについて評価することを目的とした．ヒト上顎前歯部75本を選択した．根端3mmを切除した後，#2〜#5のGates-Gliddenバーを用いて管腔を拡大した．平らな透明プラスチック容器の蓋に歯を固定し，0.1% m-cresol purpleを1mL含む0.2%アガロースゲルでプラスチック容器に満たした．次に，潅流活性化技術により，検体を針潅流，超音波潅流，EDDY，Er:YAGレーザー，ダイオードレーザーの5群に振り分けた．次亜塩素酸ナトリウムの先端部押し出しによりゲルの色調変化が生じた。容器をデジタル撮影し，各写真における潅注剤の押し出し（色の変化）の画素数の割合を算出した．ダイオードレーザー群は，針灌流，EDDY，Er:YAGレーザーに比べ，有意に低い画素数を示した（p<0.05）．超音波灌流群の灌流剤押し出し値は，EDDY群およびEr:YAGレーザー群に比べ有意に低かった（p＜0.05）．その他の群では有意差はなかった（p>0.05）．いずれの群も未熟歯に潅流液の押し出しが生じた．ダイオードレーザーと超音波洗浄では，EDDYとEr:YAGレーザーに比べ，次亜塩素酸ナトリウムの押し出しが少なかった．ニードル潅流はダイオードレーザーのみの群より潅流液の押し出しが多かった．

This study aimed to assess the apical extrusion of sodium hypochlorite in immature teeth caused by needle irrigation, ultrasonic irrigation, EDDY, Er:YAG, and diode lasers. Seventy-five human maxillary anterior teeth were selected. After the apical 3 mm of the roots was resected, the canal lumen was enlarged with #2 to #5 Gates-Glidden burs. The teeth were fixed to the lid of a flat-sided clear plastic container, and the plastic containers were filled with 0.2% agarose gel containing 1 mL of 0.1% m-cresol purple. Then, the specimens were allocated into five groups according to the irrigation activation techniques: needle irrigation, ultrasonic irrigation, EDDY, Er:YAG laser, and diode laser. The apical extrusion of sodium hypochlorite caused the color change in the gel. The containers were digitally photographed, and the percentage of pixels of irrigant extrusion (the color change) in each photograph was calculated. The diode laser group showed a significantly lower percentage of pixels than needle irrigation, EDDY, and Er:YAG laser (p < 0.05). The irrigant extrusion value of the ultrasonic irrigation group was significantly lower than that of the EDDY and Er:YAG laser groups (p < 0.05). There was no significant difference between the other groups (p > 0.05). All the groups caused irrigant extrusion in the immature teeth. The diode laser and ultrasonic irrigation caused less sodium hypochlorite extrusion than EDDY and Er:YAG laser. The needle irrigation showed more irrigant extrusion than the only diode laser group.