Mercury Amalgam Diffusion in Human Teeth Probed Using Femtosecond LIBS

Author(s)

Bello, Liciane Toledo ; da Ana, Patricia Aparecida ; Santos, Jr., Dario ; Krug, Francisco Jose ; Zezell, Denise Maria ; Vieira, Jr., Nilson Dias ; Samad, Ricardo Elgul

• Document type: Journal article
• Source: Applied Spectroscopy; v. 71, n. 4, p. 659-669, APR 2017.
• Web of Science Citations: 4

Abstract

In this work the diffusion of mercury and other elements from amalgam tooth restorations through the surrounding dental tissue (dentin) was evaluated using femtosecond laser-induced breakdown spectroscopy (fs-LIBS). To achieve this, seven deciduous and eight permanent extracted human molar teeth with occlusal amalgam restorations were half-sectioned and analyzed using pulses from a femtosecond laser. The measurements were performed from the amalgam restoration along the amalgam/dentin interface to the apical direction. It was possible to observe the presence of metallic elements (silver, mercury, copper and tin) emission lines, as well as dental constituent ones, providing fingerprints of each material and comparable data for checking the consistence of the results. It was also shown that the elements penetration depth values in each tooth are usually similar and consistent, for both deciduous and permanent teeth, indicating that all the metals diffuse into the dentin by the same mechanism. We propose that this diffusion mechanism is mainly through liquid dragging inside the dentin tubules. The mercury diffused further in permanent teeth than in deciduous teeth, probably due to the longer diffusion times due to the age of the restorations. It was possible to conclude that the proposed femtosecond-LIBS system can detect the presence of metals in the dental tissue, among the tooth constituent elements, and map the distribution of endogenous and exogenous chemical elements, with a spatial resolution that can be brought under 100 mu m. (AU)

• FAPESP's process: 05/51689-2 - Optics and Photonics Research Center at UNICAMP
• Grantee: Hugo Luis Fragnito
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 06/06746-0 - Methodology to evaluate the effects of laser irradiation in root caries prevention.
• Grantee: Patricia Aparecida da Ana
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 04/15965-2 - Implementation and development of Laser Induced Breakdown Spectroscopy (LIBS)
• Grantee: Francisco José Krug
• Support Opportunities: Research Projects - Thematic Grants