セラミックインレー．機械的サイクルとセラミックの種類が修復物と象牙質の接着強度に及ぼす影響

Ceramic Inlays: Effect of Mechanical Cycling and Ceramic Type on Restoration-dentin Bond Strength.

抄録

本研究は，上顎前歯部永久歯の5種類のセラミックインレーと象牙質との接着強さを，メカニカルサイクルの有無に関わらず評価することを目的とした．上顎前歯部永久歯100本を準備し，セラミックシステム（IPS e.Max Press，IPS e.Max CAD，Vita PM9，Vita Mark II，Vita VM7）とメカニカルサイクル（100 N，2 Hz，1.2×10(6) cycles）により10グループ（n=10）に分けた．インレーは接着剤で固着し，すべての試験片をマイクロバー（1×1 mm，ノントリミング法）に切断し，微小引張荷重を負荷して試験した。破壊モードは分類され，各セラミック表面の接触角，粗さ，および微細形状分析が実施された。象牙質とIPS e.max Pressの接着強さには，メカニカルサイクルが有意に影響した（p=0.0087）．Vita Mark II群は，メカニカルサイクルあり（9.7±1.8 MPa），メカニカルサイクルなし（8.2±1.9 MPa）の両条件で最も高い接着強さ値を示し，IPS e.Max CADは最も低い値（それぞれ2.6±1.6および2.2±1.4）であった．セラミックス／セメント界面での接着破壊モードが最も多かった．平均粗さについては，Vita Mark IIが最も高い値を示した．IPS e.max PressおよびVita Mark IIセラミックは最も低い接触角を示した。結論として，セラミックスの組成と製造工程は，セラミックス表面とレジンセメント接着強さに影響を及ぼすと思われる．また，メカニカルサイクルは象牙質とセラミックスの接着強さを著しく低下させないことがわかった．

This study aimed to evaluate the bond strength between dentin and five different ceramic inlays in permanent maxillary premolars, with and without mechanical cycling. One hundred permanent maxillary premolars were prepared and divided into 10 groups (n=10) according to the ceramic system (IPS e.Max Press; IPS e.Max CAD; Vita PM9; Vita Mark II; and Vita VM7) and the mechanical cycling factor (with and without [100 N, 2 Hz, 1.2×10(6) cycles]). The inlays were adhesively cemented, and all of the specimens were cut into microbars (1×1 mm, nontrimming method), which were tested under microtensile loading. The failure mode was classified and contact angle, roughness, and microtopographic analyses were performed on each ceramic surface. The mechanical cycling had a significant effect (p=0.0087) on the bond strength between dentin and IPS e.max Press. The Vita Mark II group had the highest bond strength values under both conditions, with mechanical cycling (9.7±1.8 MPa) and without (8.2±1.9 MPa), while IPS e.Max CAD had the lowest values (2.6±1.6 and 2.2±1.4, respectively). The adhesive failure mode at the ceramic/cement interface was the most frequent. Vita Mark II showed the highest value of average roughness. IPS e.max Press and Vita Mark II ceramics presented the lowest contact angles. In conclusion, the composition and manufacturing process of ceramics seem to have an influence on the ceramic surface and resin cement bond strength. Mechanical cycling did not cause significant degradation on the dentin and ceramic bond strength under the configuration used.