The cytotoxicity of orthodontic metal bracket immersion media.
The purpose of the present study was to evaluate the cytotoxic effects of four different orthodontic metal bracket immersion media on primary human oral gingival fibroblasts (HGFs) and one permanent human osteogenic sarcoma cell line (U2OS). Four different metal brackets (Unitek, Tomy, Ormco, and Dentaurum) were immersed in buffer solutions of NaHNO(3) (1 mM) with a pH of 4 or 7, as well as artificial saliva. The concentrations for the experiments were 0.01, 0.1, and 1.0 mul/ml. At the end of the period of bracket immersion, morphological observations were conducted using light microscopy. The tetrazolium reduction assay was used to detect the survival rate of the target cells. Statistical analysis was conducted using one-way analysis of variance. The results showed microscopically no morphological changes of the HGF or U2OS cells exposed to the metal bracket immersion media. At pH 4, the survival rates of the U2OS cells and the HGFs differed statistically for the Unitek (P = 0.003) and Ormco (P = 0.000) groups. At pH 7, the survival rate for the HGFs and the U2OS cells differed statistically for the Dentaurum (P = 0.021) and Unitek (P = 0.03) groups. The results demonstrate that differing cells exhibit various cellular reactions on exposure to metal bracket immersion media, although the four types of brackets appear to be biocompatible with HGF and U2OS cells.
Kao
Chia-Tze
CT
Institute of Medicine, Chung Shan Medical University Hospital, Taiwan.
Ding
Shinn-Jyh
SJ
Min
Yan
Y
Hsu
Ting Cheng
TC
Chou
Ming-Yung
MY
Huang
Tsui-Hsien
TH
D001672:Biocompatible Materials / Q000737:chemistry / Q000633:toxicity*; D002021:Buffers; D002478:Cells, Cultured; D003343:Corrosion; D003603:Cytotoxins / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects*; D005881:Gingiva / Q000166:cytology / Q000187:drug effects; D006801:Humans; D016910:Orthodontic Brackets; D010011:Osteocytes / Q000187:drug effects*
D001672:Biocompatible Materials; D002021:Buffers; D003603:Cytotoxins; D003722:Dental Alloys