抄録
The difference in the tissue reaction in the tissue-titanium interface between mature (22-week-old) and young (6-week-old) rats was examined by using light microscopy with decalcifiedsemi-thin sections (1μm) and undecalcified sections (40μm) and scanning electron microscopy (SEM). A titanium implant (diameter=1.0mm: height=1.5mm) was inserted into a tibia.Rats in both groups were killed on the 1st, 3rd, 5th, 7th, 14th and 28th day after operation. The bonycontact ratio and area and thickness of the newly formed bones in the undecalcified section weremeasured with an image analysis system.
On the 5th day, calcification in newly formed tissue was observed in young rats, and on the 7thday, in mature rats. On the 7th day, the mass of bone-like tissue in the mature rats was smaller thanthat in young rats. On the 28th day, the implant in both rats was almost enclosed circumferentiallywith newly-formed bone (thickness=20-30μm). However, by the image analysis, the bonycontact ratio and the area of newly formed bone in the mature rats were significantly smaller thanthose in the young rats. SEM revealed collagenous fibril-like structures (thickness=2-5μm) inthe bone-titanium interface of the mature rats, but obscure structures (thickness=0.4-0.6μm) inthat of the young rats.
