在製作固定假牙時，牙齒要修形。修形之後，必須要印模。印模前要壓排牙齦，這樣印模才會精準。臨床上排齦線為了要更好的效果，通常會添加一些化學藥品，使其具有止血、排齦的功能。排齦線置入牙齦溝內，通常會釋放化學藥品，造成牙周組織的傷害，進而影響組織的修復。先前有關排齦線的研究，多著重在討論排齦線臨床上操作的效果以及在動物體內的毒性測試，較少討論細胞毒性作用。本實驗以組織培養方式培養人類牙齦造纖維母細胞，欲探討含硫酸鋁(aluminum sulfate)、腎上腺素(dl-epinephrine)以及單純棉線(non-impregnated)三種排齦線萃取液和硫酸鋁、腎上腺素二種藥物對細胞毒性、附著以及增殖的影響。實驗結果顯示：含硫酸鋁的排齦線萃取液對細胞毒性和控制組有顯著差異(p=0.019)，但含硫酸鋁的排齦線和含腎上腺素的排齦線、單純棉線彼此間並沒有差異性存在。在細胞附著試驗方面，含硫酸鋁的排齦線萃取液對細胞附著和控制組有顯著差異(p<0.01)；而含腎上腺素的排齦線萃取液對細胞附著和控制組之間並沒有顯著差異存在(p>0.05)；但在細胞增生方面，含腎上腺素的排齦線會明顯抑制細胞增生(p<0.05)，甚至沖洗過含腎上腺素的排齦線都比沒有沖洗過含硫酸鋁的排齦線還會抑制細胞增殖(p<0.05)。綜合本實驗結果顯示，排齦線均對人類牙齦造纖維母細胞具有細胞毒性作用，如果臨床上要使用含有藥物的排齦線，如含有硫酸鋁或腎上腺素的排齦線，建議使用含硫酸鋁的排齦線較佳。 Fixed prosthodontic preparation often require subgingival margines because of caries, existing restoration, esthetic demand, or the need for additional retention. The gingival tissues must be displaced to allow sufficient impression material to be injected into the expanded gingival crevice. One of the most used methods to obtain gingival retraction is by means of medicated cord packed into the sulcus. Previous studies focus on the clinical operation and animal mode. Few article focus on the cytotoxicity of the cell. The cytotoxicity of gingival retraction cords must be investigated to ensure a safe biological response. The aim of this in vitro study was to evaluate the effect of gingival retraction cords impregnated with aluminum sulfate, dl-epinephrine and non-impregnated cord on human gingival fibroblast by in vitro. Human gingival fibroblasts from crown lenthening surgery were cultured by using an explant technique with the consent of the patient. Cytotoxicity, adhesion and proliferation of the cell were judged by using an assay of tetrazolium bromide reduction. The results showed that aluminum sulfate was cytotoxic to primary human fibroblast when compared to control group. But no significant difference noted among aluminum sulfate, dl-epinephrine and non-impregnated cord. Aluminum sulfate alone can inhibit cell adhesion. But dl-epinephrine inhibits cell proliferation very seriously even elute gingival retraction cord. No significant difference was found between aluminum sulfate and non-impregnated cord. This study suggests that gingival retraction cords containing epinephrine may not be better than cord containing aluminum sulfate. If dentists want to use the impregnated gingival retraction cord, we suggest to use the gingival retraction cord containing aluminum sulfate.
