Effect of temperature variation on the cytotoxicity of cast dental alloys and commercially pure titanium

Abstract

Cell culture system has been used to evaluate alloy cytotoxicity under different environments, testing the extracts, but the effect of temperature variation on the cytotoxicity of dental alloys has not been analyzed. Objective: The aim of the present study was to investigate if temperature variation could affect dental alloy cytotoxicity, testing alloy extracts in an epithelial cell culture system. Material and methods: Discs of Ni-Cr, Co-Cr-Mo, Ni-Cr-Ti, Ti-6Al-4V and commercially pure titanium (cp Ti) were cast by arc melting, under argon atmosphere, injected by vacuum-pressure. Discs were immersed in artificial saliva and subjected to different temperatures: 37°C and thermocycling (37°C/5°C/37°C/55°C/37°C). After thermocycling, extracts were put in a subconfluent culture during 6 h, and the number of cells and their viability were used to evaluate cytotoxicity in these temperatures. For each alloy, data from temperature conditions were compared by Student's t-test (α=0.05). Results: The cytotoxicity tests with alloy/metal extracts showed that Ni-Cr, Co-Cr-Mo, Ti-6Al-4V and cp Ti extracts (p>0.05) did not affect cell number or cell viability, while Ni-Cr-Ti (p<0.05) extract decreased cell number and viability when the alloy was subjected to thermocycling. Conclusion: Within the limitations of the present study, the Ni-Cr-Ti alloy had cell number and viability decreased when subjected to temperature variation, while the other alloys/metal extracts did not show these results.

Experimental titanium alloys for dental applications

“…26,30,37 Moreover, the biocompatibility of dental alloys has been evaluated with this SCC9 lineage. 30,37 No difference in cell proliferation and viability was noted among experimental alloys and CP Ti at any of the evaluated periods. These results prove the in vitro biocompatibility of experimental alloys.…”

Intimal sarcoma in an inflammatory aneurysm after endovascular aneurysm repair

“…8,9 Nickel and titanium alloys promote an inflammatory response in soft tissue by activating human monocytes 10 and can change cellular vulnerability to extreme temperatures, potentially signifying oncogenic alterations in antiapoptotic pathways. 11 Thus, placement of endovascular stents in aneurysms that already demonstrate inflammation may theoretically potentiate an existing predisposition to vascular neoplasia, especially in younger patients with stronger innate and adaptive immunity. 12 One plausible explanation could be pre-existing tumor in the setting of intense inflammation in the original aneurysm sac, analogous to a previous description of carotid artery leiomyosarcoma, 13 although this has not been described in inflammatory aortic aneurysms.…”

Estimation of the reliability of all-ceramic crowns using finite element models and the stress–strength interference theory

“…The calculation of the failure possibility was based on the distributions of the variables [14,15]. The parameters in the reliability analysis, such as the occlusal loading area, the magnitude of the occlusal load, the thermal load and the strength limit of the materials, were acquired from a statistical analysis of published data [16][17][18][19][20]. The stress-strength reliability problem has been addressed for normally distributed stress and strength variables [21,22].…”