Cytotoxicity of some solutions used for root canal treatment assessed with unman fibroblasts and lymphoblasts

Abstract

Abstract— The cytotoxicity of seven solutions used in root canal therapy was tested in human fibroblast and lymphoblast cultures. The amount of cell damage was assessed by measuring the release of 51Cr form labeled cells into the medium. The solutions, When applied at therapeutic concentrations, displayed high toxicity in vitro and difference in cytotoxicity were seen between different solutions. Generally, lymphoblasts were found to be more sensitive than fibroblasts. The cytotoxic profiles of the two cell types resembled each other except when 5% sodium bypochlorite or 0.2% Hibitance was used. When the criterion of total cell lysis was 50%51Cr release, The toxic concentrations of the solutions tested ranged between 1:25 and 1:900 (v/v) for fibroblasts. For lymphoblasts the corresponding concentration range was between 1:40 and 1:750. Despite technical simplicity and good reproducibility the 51Cr release method proved unreliable for testing the cytotoxicity of endodontic solutions. Because the methodological errors cannot be foreseen the 51Cr release method requires supproting evidence form other methods.

Factors promoting the tissue dissolving capability of sodium hypochlorite

“…This important property of NaOCl does distinguish it from most endodontic medicaments or irrigants, except physiological saline and iodine-potassium iodide solution (as well as the infrequently used citric or lactic acids). The very toxic effects of NaOCl in tissue cultures (Spangberg et al 1973, Koskinen et al 1981) and the acute toxicity in cases of accidents (Becker et al 1974) stand in sharp contrast t o the histological absence of toxic or irritant effects in the subcutaneous placement of NaOCl in guineapigs (Thd e t al. 1980), or in the teeth of monkeys (Lamers et el.…”

The testing of endodontic materials in vitro

“…1972) " Human embryonic lung epithelium (Vander Wall f/fl/. 1972) Human Hela epithelium (Kantz et al 1974) Bovine pulp fibroblasts (Munaco et al 1978) Human pulp fibroblasts (Koskinen et al 1980) Human lymphoblasts (Koskinen et al 1981) Human lung fibroblasts (Masillamoni et al 1981) Human erythrocytes (Moller & Hensten-Pettersen 1985) Human skin epithelium (Moller & Hensten-Pettersen 1985) Human oral epithelium (Nakamura et al 1986) Human lymphocytes and monocytes (Zmener & Cabrini 1986) Logically, the same cell types as exist clinically, should be used. Around the apex of a tooth there are many cell types, the commonest being fibroblasts and osteoblasts.…”

Some factors affecting the concentration of available chlorine in commercial sources of sodium hypochlorite

“…1980, Thé et al . 1980, Koskinen et al . 1981) and desirability to prevent damage to dentine (Grigoratos et al .…”