J Korean Acad Prosthodont.  1999 Dec;37(6):717-729.

CYTOTOXICITY OF DENTAL CAST BASE METAL ALLOYS ON HUMAN ORAL KERATINOCYTES

• Choi YJ
• Chung MK
• Yook JI

Abstract

Although many studies on the cytotoxicity of the dental cast metal alloys and their components have been carried out, the results are rather conflicting because of the different type of cells used and the various experimental procedures taken. Recently, a number of scientists have claimed that it would be preferable to focus on the use of cells from relevant specific location of the human bodies. Consequently, the primary cultured oral keratinocyte derived from oral mucous along with nickel chloride and several of widely used dental cast base metal alloys(two-Ni-Cr alloys and one Co-Cr alloy)in domestic were selected for this study, from which 1) The amounts of released metal ions were determined using atomic absorption spectrometry, 2) The cytotoxicity of nickel chloride and dental cast base metal alloys was evaluated via MTT assay, and finally, 3) The amounts of released metal ions and the cytotoxicity of nickel chloride were correlated with the cytotoxicity of dental cast base metal alloys And, the results were summarized as follows ; 1. Nickel ion from Ni-Cr alloys and Cobalt ion from Co-Cr alloys resulted in maximum releasing rate during first 24 hours, followed by a decrease in releasing rate with time. Chromium ion were found to be minimal in all alloys. 2. In cytotoxic test, with 40muM, 80muM of nickel chloride, there were observed an increase in the relative cell number compared to control samples after 24 hours. With 160muM, there was found to be no difference in the relative cell number with control, except that 48 hour showed a increase in relative cell number. With 320muM, the relative cell number remained constant and decreased after 48 hours, and with 640muM, a continuing decrease in relative cell number was observed throughout test period. 3. The sensitivity of primary cultured oral epithelium to nickel was lower compared to the cells used in other studies. 4. CB-80 Soft and Regalloy showed no cytotoxicity to primary cultured oral epithelium and New crown resulted in a slight cytotoxicity. In conclusion, it was shown that the primary cultured oral keratinocytes could be applied successfully as testing cells in cytotoxicity test. Futhermore, the dental cast base metal alloys used in this study were found to be biocompatible.

MeSH Terms

Absorption
Alloys*
Cell Count
Chromium
Cobalt
Crowns
Epithelium
Human Body
Humans*
Ions
Keratinocytes*
Nickel
Spectrum Analysis
Alloys
Chromium
Cobalt
Ions
Nickel