従来型グラスアイオノマーセメントの1年間の生体内機能発現後の界面特性．

Interfacial Characterization of a Conventional Glass-Ionomer Cement after Functioning for 1-year In Vivo.

抄録

目的:

サル歯に従来型グラスアイオノマーセメント（GIC）を装着し、装着1日後の象牙質との界面、および1年間の経年変化・機能発現後の界面の変化を形態学的に評価すること。

PURPOSE: To morphologically evaluate the interface between a conventional glass-ionomer cement (GIC) and dentin one day after placement, as well as the changes at the interface after one year of aging/functioning in monkey teeth.

材料および方法:

2頭のサルの無傷の歯7本の頬側表面に、浅いクラスVキャビティを作製し、Fuji IX GP（GC）を充填し、1年間のin vivoデータを提供した。1年後，各サルのさらに2本の歯を同様に調製・修復し，1 day in vivoグループとした．翌日、修復した歯を抜歯し、透過型電子顕微鏡（TEM）で修復物の界面を観察した。また，ヒトの抜去歯2本（コントロール，1day in vitro群）にも同様に修復物を装着し，装着後1日でTEMで観察した．

MATERIALS AND METHODS: On the buccal surfaces of seven intact teeth in each of two monkeys, shallow class V cavities were prepared, which were then filled with Fuji IX GP (GC) to provide 1-year in vivo data. A year later, two more teeth in each monkey were similarly prepared and restored for the 1-day in vivo group. The following day, the restored teeth were extracted and the restoration interfaces observed using transmission electron microscopy (TEM). In addition, restorations were similarly placed in two extracted human teeth (control, 1-day in vitro group) and observed a day after placement using TEM.

結果:

1日間のin vivoおよびin vitroの結果から，GICはレジン系接着剤のハイブリッド層と同様に脱灰帯を介して象牙質に接着しているように見えた．しかし，1年後のin vivoではGICと象牙質の界面が経時的に変化しており，再石灰化層内やコラーゲン線維に沿って多数の針状結晶が検出された．イオンの遅い拡散により細孔が生じ，それが鉱物の結晶で満たされ細孔が小さくなった。

RESULTS: The 1-day in vivo and in vitro results showed that the GIC appeared to bond to dentin through a demineralized zone similar to the hybrid layer produced by resinous adhesives. However, the interface between GIC and dentin after 1 year in vivo appeared to change over time: many needle-like crystals were detected within the remineralized layer and along the collagen fibrils. Slow diffusion of ions resulted in pores, which filled with mineral crystals and made the pores smaller.

結論:

GICと象牙質の界面が経時的に形態変化し、界面での再結晶や再石灰化が起こる可能性がある（1年 in vivo）。

CONCLUSION: The interface between GIC and dentin morphologically changes over time, and recrystallization or remineralization at the interface may occur (1 year in vivo).