短繊維強化複合材料とガラスセラミック固定部分床義歯の耐荷重性と摩耗特性

Load-bearing capacity and wear characteristics of short fiber-reinforced composite and glass ceramic fixed partial dentures.

抄録

本研究の目的は，実験的な短繊維強化複合材料（SFRC）と従来の二ケイ酸リチウムCAD/CAM作製固定部分床義歯（FPD）の耐荷重性と摩耗性能を評価することである．2群（n＝12/群）の3単位CAD/CAM作製後方FPDを作製した．第1群は実験用SFRCブロックを用い、第2群はリチウムジシリケートを用いて作製した（IPS e.max CAD）。FPDはすべてジルコニア製試験治具にデュアルキュア型レジンセメントを用いて作製した。各グループの半数のFPDに破折するまで準静的荷重をかけた。残りの半数は、準静的荷重を破断まで負荷する前に繰り返し疲労時効（100.000サイクル、Fmax = 500N）を受けた。破壊モードはSEMで調べた。摩耗試験は、15,000負荷サイクルで実施した。材料の種類と時効の両方が、FPDの耐荷重性に大きな影響を与えた。疲労時効なしの実験用SFRC CADは、耐荷重が最も大きかった（2096±149N）。繰返し疲労時効はSFRCグループの耐荷重を減少させたが（1709±188N），リチウムジシリケートグループの耐荷重は増加した（1546±155N）．摩耗深さはSFRC CAD（29.3μm）がリチウムジシリケート（54.2μm）より有意に低かった．実験用SFRC CADは，繰返し疲労時効の前後で最も高い耐荷重性を示し，対照材料と比較して優れた摩耗挙動を示した．

The aim of this study was to evaluate load-bearing capacity and wear performance of experimental short fiber-reinforced composite (SFRC) and conventional lithium-disilicate CAD/CAM fabricated fixed partial dentures (FPDs). Two groups (n = 12/group) of three-unit CAD/CAM fabricated posterior FPDs were made. The first group used experimental SFRC blocks, and the second group fabricated from lithium-disilicate (IPS e.max CAD). All FPDs were luted on a zirconia testing jig with dual-curing resin cement. Half of FPDs per group were quasi-statically loaded until fracture. The other half experienced cyclic fatigue aging (100.000 cycles, Fmax = 500 N) before loading quasi-statically until fracture. Fracture mode was examined using SEM. Wear test was performed using 15,000 loading cycles. Both material type and aging had a significant effect on the load-bearing capacity of FPDs. Experimental SFRC CAD without fatigue aging had significantly the highest load-bearing capacity (2096 ± 149N). Cyclic fatigue aging decreased the load-bearing capacity of the SFRC group (1709 ± 188N) but increased it for the lithium-disilicate group (1546 ± 155N). Wear depth values of SFRC CAD (29.3μm) were significantly lower compared to lithium-disilicate (54.2μm). Experimental SFRC CAD demonstrated the highest load-bearing capacity before and after cyclic fatigue aging, and superior wear behavior compared to the control material.