CAD/CAMセラミッククラウン修復物の接着性向上のための適切な即時象牙質封鎖法について

Appropriate Immediate Dentin Sealing to Improve the Bonding of CAD/CAM Ceramic Crown Restorations.

抄録

本研究は，マイクロ引張接着強さ（μTBS）に基づく定量的・定性的評価により，CAD/CAMセラミッククラウン修復物の接着性向上に適した即時象牙質シーリング（IDS）法を明らかにすることを目的とした．48本のヒト大臼歯を抜去し，標準化した支台歯標本を作製し，IDSを行わない群（C群：コントロール），オールインワン接着システムを単独で適用して行うIDS（A群），接着システムと流動性樹脂複合体を組み合わせて行うIDS（F群）の3群に分類した．すべての試料は，チェアサイドCAD/CAMシステムで製作したセラミッククラウンで修復し，無応力群と応力群に分けた．応力負荷群の試験片に繰返し荷重（78.5 N，3×105回，90回/分）を負荷した後，すべての試験片を切片化した．咬合壁および中軸壁のμTBS値を測定し（=16），統計的に分析した．A群およびF群の定量的接着性能は，繰返し荷重および支台歯壁条件にかかわらず，C群より優れていた．質的な接着性能では，F群が臨床的咀嚼を模擬した繰返し荷重条件下でも最大の接着強さと高い接着耐久性を示した．

This study aimed to use quantitative and qualitative evaluations based on micro-tensile bond strength (μTBS) to clarify the appropriate immediate dentin sealing (IDS) approach for improving the bonding of CAD/CAM ceramic crown restorations. Forty-eight extracted human molars were prepared to obtain standardized abutment specimens and divided into three groups: no IDS (group C: control), IDS performed by a single application of an all-in-one adhesive system (group A), and IDS performed by the combined application of an adhesive system and a flowable resin composite (group F). All specimens were restored with a ceramic crown fabricated by a chair-side CAD/CAM system and were divided into no-stress and stressed groups. After cyclic loading (78.5 N; total, 3 × 105 cycles; 90 cycles/min) on the specimens in the stressed group, all specimens were sectioned. The μTBS values for the occlusal and mesioaxial walls were measured ( = 16) and analyzed statistically. The quantitative bonding performance of groups A and F were superior to that of group C, regardless of the cyclic loading and abutment wall conditions. Group F showed the maximum bond strength and the highest bond durability in the qualitative bonding performance even under the cyclic loading condition simulating clinical mastication.