Date of Award
Spring 1-1-2013
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Liu, Dawei
Second Advisor
Hefti, Arthur
Third Advisor
Bosio, Jose A.
Abstract
Introduction: Cytotoxicity is a major concern in the clinical application of dental
materials including Temporary Anchorage Devices (TADs). The purpose of this study
was to test the cytotoxicity of four of the commercially available brands of TADs
(Aarhus, American Orthodontics; Dual top, RMO; Vector TAS, ORMCO; Unitek TAD,
3M UNITEK).
Materials and Methods: Twenty-four (six from each brand) TADs were individually
incubated in complete cell culture medium and shaken at a rate of 1.5 rpm at 37ºC for 30
days to generate the conditioned medium (CM). To test the cytotoxicity, human
periodontal ligament fibroblasts (hPDLF) were exposed to the CM for 24 hours. As
endpoints, morphological changes were observed along with cell death and damage
which were quantified by MTT and LDH assays, followed by statistical analysis of oneway
ANOVA with Bonferroni adjustment.
Results: No morphological changes were found in any of the four types of TADs
compared to the control cells. LDH assay showed that none of the tested TADs caused
significant cell death after CM treatment in contrast to the positive control (P > 0.05). No
significant intragroup differences were found between any of the four brands of TADs (P
> 0.05). MTT assay showed similar results as for the LDH assay, except for a marginally
significant increase of MTT release found in the TADs from 3M UNITEK compared to
the negative control (P = 0.047).
Conclusions: According to the ISO10993:5 standards, none of the tested TADs exhibited
statistically significant cytotoxicity, suggesting their safe clinical application.