Search PubMed⌕ Search

Biomedical subjects

S D Meryon

Publications and source records attributed to S D Meryon.

33 records · Page 2Linked to original sources
PubMed1984

In vitro cytotoxicity of a glass ionomer cement of a new generation.

The new glass ionomer dental cement, ChemFil, was found to be moderately cytotoxic when freshly mixed in vitro. This was assessed by a reduction in fibroblast and macrophage counts following 24 h exposure to the material, and by alterations in enzyme levels and enzyme staining kinetics relative to control cultures. Testing of set samples of the material showed that its toxicity decreased rapidly with setting. ChemFil behaved in a manner similar to two older glass ionomers, ASPA and ChemBond, although it was generally slightly less irritant.

Acrylic Resins↗
PubMed1984

The influence of dentine on the in vitro cytotoxicity testing of dental restorative materials.

Few in vitro systems for testing dental restorative materials have taken into account the protection afforded by the residual dentine in vivo. In turn opinions differ as to whether an increase in residual dentine thickness increases this protection. In this study an increase in the depth of dentine powder beneath zinc oxide eugenol (ZOE) reduced its toxicity, while this was not the case with the glass ionomer cement. Compaction of the powder had no effect, suggesting that protection was due to binding of the toxicant to the dentine rather than it acting as a physical barrier. Protein was shown to be very important in moderating the cytotoxicity of ZOE. These results suggest that in vivo the irritancy of some materials may be related to the depth of residual dentine but not others. The effect of exposure period and volume of these materials on their cytotoxicity was also investigated. Increasing the volume of ZOE while retaining the same surface area increased the toxicity of ZOE, while with the glass ionomer it had no effect.

Animals↗
PubMed1984

The effect of zinc on the biocompatibility of dental amalgams in vitro.

When freshly triturated, two zinc-containing amalgams, Velvalloy and Dispersalloy, were more cytotoxic in vitro than two zinc-free amalgams Amalcap and Sybraloy. The high copper amalgam, Sybraloy, was only slightly irritant: similarly the presence of copper in Dispersalloy did not increase its toxicity over Velvalloy. All four amalgams retained some degree of toxicity up to one month after setting which is in marked contrast to most other dental materials investigated previously. This was greatest with the zinc-containing amalgams and was accompanied by the continued release of zinc over this period.

Animals↗
PubMed1983

Evaluation of the cytotoxicity of four dental materials in vitro assessed by cell viability and enzyme cytochemistry.

The cytotoxic effects of zinc phosphate and silicate cements, Concise composite and zinc oxide/eugenol were evaluated after 24 h in an in vitro system which simulates the clinical usage of the material, and the results compared with those using phenol. Data of gross changes affecting cell viability placed these materials in ranking order of increasing severity: Concise less than zinc phosphate less than Silicap much less than zinc oxide/eugenol. More discrete changes involving alterations in enzyme cytochemistry were assessed and the significance of the results discussed. The presence of dentine powder in the system reduced the cytotoxic effects on these materials.

Animals↗
PubMed1983

A comparison of the in vitro cytotoxicity of two glass-ionomer cements.

The in vitro cytotoxicity of two glass-ionomer cements--ASPA and ChemBond--was compared using a model cavity system which simulates the in vivo situation. Both materials were cytotoxic to fibroblasts and macrophages, although differences were observed in the time scale and magnitude of the response elicited.

Animals↗
PubMed1982

A comparison of the in vitro cytotoxicity of four restorative materials assessed by changes in enzyme levels in two cell types.

A system is described for assessing the toxicity of freshly mixed restorative materials in vitro by measuring changes in the levels of beta-galactosidase and lactic dehydrogenase in both cultured cells and supernatants. The toxic effects of a zinc phosphate and silicate cement, a composite, and zinc oxide/eugenol were studied on two cell types, macrophages and fibroblasts, after 24 h exposure. Zinc oxide/eugenol, Silicap, and zinc phosphate were toxic to macrophages, in that order; Concise appeared to be nontoxic. Only zinc oxide/eugenol exerted significant effects on fibroblasts. Interposing dentine powder between the test cells and the material ameliorated the effects of all materials, possibly by the absorption of toxic components.

Acrylic Resins↗