Date of Award

Summer 2019

Document Type


Degree Name

Master of Science (MS)



First Advisor

Nimeri, Ghada

Second Advisor

Lobner, Douglas

Third Advisor

Liu, Dawei


Objectives:Orthodontic appliances with silver soldering can be in the oral cavity for several years and very few studies have been done to detect the biosafety of the silver solders. The aim of this in vitro study was to compare the cytotoxicity effects of two different solder materials on Human Periodontal Ligament Fibroblast cells (HPLF).Methods:Two commonly used solder materials from two companies, (Leone and Summit) with different metal elements and percentages were studied. The solder samples were exposed to HPLF cells for 48 hours and the cytotoxicity effect of soldered materials on HPLF cells was measured via the MTT colorimetric assay (n=10/sample) and morphological microscopic analysis. Furthermore, the mechanism of cytotoxicity of the Summit silver solder was investigated using both a caspase inhibitor Z-VAL-Ala-Asp-flu-oromethylketone (ZVAD) and the free radical scavenger Trolox (n=8/sample). Statistical analysis was performed with a one-way analysis of variance (ANOVA) with a Bonferroni correction. PResults:Compared to control (cells only), both Leone silver solder and Summit silver solder were cytotoxic (pConclusions:The stainless steel bands were significantly cytotoxic compared to the control. Furthermore, the two silver solder materials demonstrated different levels of cytotoxicity to HPLF cells. Summit silver solder showed significantly higher cytotoxicity than Leone silver solder.

Included in

Dentistry Commons