Date of Award

Spring 1-1-2013

Document Type


Degree Name

Master of Science (MS)



First Advisor

Liu, Dawei

Second Advisor

Hefti, Arthur

Third Advisor

Bosio, Jose A.


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,


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.