直接接着法および間接接着法による矯正用ブラケットのせん断接着強度の比較と

Comparison of Shear Bond Strength of Orthodontic Brackets Using Direct and Indirect Bonding Methods and .

抄録

研究目的:

本稿の目的は，間接接着と直接接着の歯列矯正ブラケットのせん断接着強さを比較することである。

Aim: Aim of article was to compare the shear bond strength of indirectly and directly bonded orthodontic brackets.

材料および方法:

実験には60本の上顎と下顎の小臼歯を使用した。歯は1歯ずつ別々にコールドキュアアクリルブロックに装着し、直接接着型ブラケット（30歯）と間接接着型ブラケット（30歯）の2群に分けた。ブラケット（Discovery, Roth 0.022", Dentaurum, Ispringen, Germany）は，直接法ではTransbond XT（3M Unitek, Monrovia, CA, USA）を，間接法ではTransbond XTとSondhi Rapid Set（3M Unitek, Monrovia, CA, USA）を併用して接着を行った．せん断接着強さと接着剤残存率（ARI）を評価した．本研究では，間接的に接着したブラケットを15名，直接的に接着したブラケットを15名，合計30名の被験者を対象とした．6ヶ月間の生存率を評価した．

Materials and methods: The experimental study included 60 maxillary and mandibular premolars. Teeth were mounted on cold-cure acrylic blocks for each tooth separately and divided into two groups: directly bonded brackets (30 teeth) and indirectly bonded brackets (30 teeth). Brackets (Discovery, Roth 0.022", Dentaurum, Ispringen, Germany) were bonded using Transbond XT (3M Unitek, Monrovia, CA, USA) in direct method, while in indirect technique, a combination of Transbond XT and Sondhi Rapid Set (3M Unitek, Monrovia, CA, USA) was used. The shear bond strength and adhesive remnant index (ARI) were evaluated. The study included 30 subjects - 15 with indirectly bonded brackets and 15 with directly bonded brackets. Survival rate was assessed during the period of 6 months.

結果:

直接法（7.48±1.61MPa）と間接法（7.8.2±1.61MPa）では，せん断接着強さに統計的有意差は認められなかった．また，両法とも歯面上の接着剤残渣はほぼ同量であった（中央値＝1，四分位範囲＝1～2）．また，ブラケット残存率には両法で有意差は認められなかった．

Results: No statistically significant difference in the shear bond strength was found in direct (7.48±1.61 MPa) and indirect labial bonding methods (7.8.2±1.61 MPa). Both methods produced very similar amount of adhesive remnant on tooth surface (median = 1; interquartile range 1-2). There were no significant differences in bracket survival rate between methods.

結論:

矯正用ブラケット接着の方法としては，間接法，直接法ともに，せん断接着強さ，歯面上の接着剤残存量，残存率に関して，臨床上，同等の価値があると思われる．

Conclusion: Regarding the shear bond strength, adhesive remnant on tooth surface, and survival rate, both indirect and direct methods of orthodontic bracket bonding seem to be equally valuable methods in clinical practice.