Scanning Electron Microscopic Study on Root Canal Cleansing Effect in Fine Curved Root Canal : The First Report : Cases of Using Standard Cleansing Needle

Abstract

Extracted maxillary and mandibular molars with the curved fine root canal untreated were employed ． Enlarging and preparatiQn of the root canals were made with K − files after the root canals were filled with distilled water ． Then the root canals were given 1 − minute irrigation with 2ml of 1 ． 25％ − 5％ NaOCI held in the syringe with a standard needle ， and continuously with 1 ． 875 ％ − 7 ． 5％ EDTA ． In another group the same irriga − tion procedure was used with distilled water ． Inner wall surfaces were observed through scanning electron microscope ． The results were as follows ： 1 ． When the canals were cleansed with water only ， or with ユ． 25 ％ NaOCI and 1． 875％ EDTA ， smeared layer was observed in mid − canal and root apex ； the root canaI could not be cleansed sufficiently ． 2 ． When the canals were cleansed with 2 ． 5％ − 5％ NaOCI and 3． 75％ − 7 ， 5％ EDTA ， cleansing effect was sufficient at mld − canal but insufficient at root apex ． 3 ・ In order to increase cleansing effect on root canals ， abundant use of the irrigation agents and more prolonged time for cleansing appear to be necessary ． Key w rds ゴ 〃 ず 8 ・ ation agents ／ Roo ' canal cleansing effect ／ F 加 θ curved 厂oo ' ご α 砌