Detection of trace metallic elements in oral lichenoid contact lesions using SR-XRF, PIXE and XAFS

Abstract

Oral lichen planus (OLP) and oral lichenoid contact lesions (OLCL) are chronic inflammatory mucocutaneous reactions with a risk of malignant transformation that alter the epithelium. OLP and OLCL have similar clinical and histopathological features and it is difficult to distinguish one from the other. Metallic restorations are suspected to generate OLCLs. Trace metal analysis of OLCL specimens may facilitate the discrimination of symptoms and identification of causative metallic restorations. The purpose of this study was to assess OLCL tissue samples for the prevalence of metallic elements derived from dental restorations, and to discriminate OLCL from OLP by using synchrotron radiation-excited X-ray fluorescence analysis (SR-XRF), particle-induced X-ray emission (PIXE), and X-ray absorption fine structure (XAFS). Typical elements of dental materials were detected in the OLCL, whereas no obvious element accumulation was detected in OLP and negative control specimens. The origin of the detected metallic elements was presumed to be dental alloys through erosion. Therefore, our findings support the feasibility of providing supporting information to distinguish OLCL from OLP by using elemental analysis.

Effects of experimental pastes containing surface pre-reacted glass ionomer fillers on inhibition of enamel demineralization

“…By focusing the incident beam down to micron size and scanning over the specimen surface, "micro-PIXE" can also provide images of the trace elemental distribution with high spatial resolution (μm scale) and high sensitivity 21,22) . The method has been used to analyze the distribution of trace heavy elements contained in various soft and hard tissues [23][24][25][26] . The purpose of this study was to evaluate the inhibitory effects of experimental pastes containing S-PRG fillers on bovine enamel demineralization using micro-CT, scanning electron microscope (SEM) and micro-PIXE.…”

Vascularization in interconnected 3D printed Ti-6Al-4V foams with hydrogel matrix for biomedical bone replacement implants

“…Another challenge to tackle in designing a living implant is the release of potentially toxic metal debris which can be attributed to mechanical loading on the material. In several cases, Ti-6Al-4V particulate debris has been found in oral mucosa of patients with dental implants of this material [26].…”

Degradation mechanism of a high-performance real micro gas sensor, as determined by spatially resolved XAFS

“…The m-XAFS with mm or nm resolution has been applied to various fields, e.g. catalysis [9][10][11][12][13] and biomedical, [14][15][16][17] geological and environmental sciences. [18][19][20] In our previous report we found that PdO particles in the fresh m-gas sensor were reduced to Pd metal as the methane selectivity decreased.…”