最近は外が暗くなるのも早くなりましたね。

冬至までは更に日の入りが早くなるのかと

思っていましたが

実際には、冬至の半月程前が一番早く

今がまさにピークだということです。

外は暗くても、明るい家の中で勉強をしたいと思います。

今回はガッタパーチャーの生体為害性についての論文です。

ガッタパーチャーの粒子の大きさや表面性状によって

生体の炎症反応に違いがあるのか、モルモットで実験しています

Tissue reaction to gutta-percha was studied using subcutaneously implanted Teflon cages in guinea pigs. Gutta-percha was tested in three forms: (i) as large particles prepared by dividing gutta-percha cones into pieces, (ii) as fine particles prepared by ball-milling of gutta-percha, and (iii) as particles produced by dissolving gutta-percha in rosin-chloroform. Gutta-percha evoked two distinct types of tissue response. The large pieces were well encapsulated and the surrounding tissue was free of inflammation. The fine particles evoked an intense, localized tissue response, characterized by the presence of macrophages and multinucleated giant cells. The rosin-chloroform treated gutta-percha induced a similar tissue reaction to that observed with the fine particles of gutta-percha. In addition, cell remnants were present in association with the material, which indicates an initial toxicity to rosin-chloroform treated gutta-percha. These results show that the size and surface character of gutta-percha can determine the type of tissue reaction to the material. The accumulation of macrophages around gutta-percha may be an important factor in the impairment of healing of periapical lesions when teeth are root filled with excess material.

つまり

根尖からオーバーし細粒化したガッタパーチャーは

周囲に多数のマクロファージを纏い

炎症を起こしやすいということです。

再根管治療時ガッタパーチャーを除去する際は

ファイル等によって細粒化したものを根尖孔外に

押し出さないように注意しなければいけないことを

再確認できました。

引用文献

Sjögren U, Sundqvist G, Nair PN.

Tissue reaction to gutta-percha particles of various sizes when implanted subcutaneously in guinea pigs.

Eur J Oral Sci. 1995 Oct;103(5):313-21.