根管内におけるファイバーポストの接着性に及ぼす架橋型キトサンナノ粒子の効果．

Effect of Crosslinked Chitosan Nanoparticles on the Bonding Quality of Fiber Posts in Root Canals.

抄録

目的:

根管内象牙質を架橋剤EDCとキトサンナノ粒子（Csnp）で前処理することにより，根管内ファイバーポストの接着強度，ナノリーク，コラーゲン劣化の定量化，接着剤の転化度（DC）の観点から，接着性に及ぼす影響を検討する．

PURPOSE: To investigate the effects of root-canal dentin pretreatment with the crosslinker EDC combined with chitosan nanoparticles (Csnp) on the bonding quality of fiber posts in root canals in terms of bond strength, nanoleakage, quantification of collagen degradation, and degree of conversion (DC) of adhesive.

材料および方法:

48本の片根歯が歯内療法で準備され，ファイバーポストの接着手順に従い，UNI-ETCH（Bisco社製）を用いてエッチングされた．接着剤（All-Bond 3）塗布前の前処理として，a. 2.5%グルタルアルデヒドに24時間浸漬，b. Csnp溶液で60秒超音波撹拌処理後EDCクロスリンカーに24時間浸漬，c. 無処理（コントロール）をランダムに3群に分類し，前処理を比較した．接着強度，ナノリーク，界面内のDC，およびコラーゲン繊維の劣化を評価した．

MATERIALS AND METHODS: Forty-eight single-rooted teeth were prepared endodontically and etched using UNI-ETCH (Bisco) as per the adhesive procedure for fiber posts. They were randomly divided into three groups before adhesive (All-Bond 3) application, according to different pretreatments: a. immersed in 2.5% glutaraldehyde for 24 h; b. treated with Csnp solution under ultrasonic agitation for 60 s and immersed in EDC crosslinker for 24 h; c. without treatment (control). Bond strength, nanoleakage, DC within the interface, and collagen fiber degradation were evaluated.

結果:

前処理は根管内におけるファイバーポストの接着安定性に有意な影響を及ぼしたが，変換の程度には影響を及ぼさなかった（p = 0.552）．酵素分解は，全群で接着強さに有意な影響を及ぼし（p = 0.001），c群で最も大きな効果が認められた．接着界面から放出されるアミノ酸量は，加水分解および酵素分解後に群間で有意差があり（p = 0.000 ），c群で最も多量のアミノ酸が放出された．

RESULTS: The pretreatments had a significant influence on the bonding stability of fiber posts in root canals, but not on the degree of conversion (p = 0.552). Enzymatic degradation significantly influenced bond strength for all groups (p = 0.001), with the greatest effect found in group c. The amount of amino acids released from the adhesive interface differed significantly between groups after hydrolysis and enzymatic degradation (p = 0.000); group c released the highest amount of amino acids.

結論:

CsnpとEDCの併用により，象牙質への結合は象牙質コラーゲンの分解を抑制し，接着剤重合を阻害することなく接着界面の安定性を向上させた．

CONCLUSIONS: Csnp binding to dentin in combination with EDC reduced degradation of dentinal collagen and improved the stability of the adhesive interface without jeopardizing adhesive polymerization.