Patient shielding during dentomaxillofacial radiography: Recommendations from the American Academy of Oral and Maxillofacial Radiology.

BACKGROUND: The American Academy of Oral and Maxillofacial Radiology established an ad hoc committee to draft evidence-based recommendations and clinical guidance for the application of patient contact shielding during dentomaxillofacial imaging. TYPES OF STUDIES REVIEWED: The committee reviewed monographs and reports from radiation protection organizations and studies that reported radiation dose to gonads, breasts, and thyroid gland from dentomaxillofacial imaging. RESULTS: Considering the absence of radiation-induced heritable effects in humans and the negligible dose to the gonads and fetus from dentomaxillofacial imaging, the committee recommends discontinuing shielding of the gonads, pelvic structures, and fetuses during all dentomaxillofacial radiographic imaging procedures. On the basis of radiation doses from contemporaneous maxillofacial imaging, the committee considered that the risks from thyroid cancer are negligible and recommends that thyroid shielding not be used during intraoral, panoramic, cephalometric, and cone-beam computed tomographic imaging. PRACTICAL IMPLICATIONS: This position statement informs and educates the reader on evolving radiation protection practices and provides simple, unequivocal guidance to dental personnel to implement these guidelines. State and local authorities should be contacted to update regulations to reflect these recommendations.

Investigation of foreign materials in gingival lesions: a clinicopathologic, energy-dispersive microanalysis of the lesions and in vitro confirmation of pro-inflammatory effects of the foreign materials.

OBJECTIVES: This study aimed to evaluate the clinical and histopathologic features of gingival lesions containing foreign material (GLFMs). In parallel, the composition of the foreign material and its effects in primary human gingival fibroblasts (HGFs) were investigated. STUDY DESIGN: Eighty-six GLFMs were retrieved from an oral pathology biopsy service. Clinical and microscopic data were analyzed, and the composition of the particles was identified by using energy-dispersive X-ray spectroscopy (EDX). Furthermore, HGFs were stimulated with silica (SiO2) microparticles to investigate the production of collagen type 1 (COL-1), matrix metalloproteinase 2 (MMP2), and inflammatory cytokines. RESULTS: GLFMs were most commonly found in women (60.5%) and most frequently described as white plaques. Histopathologic examination identified verrucous hyperplasia in 59% and epithelial dysplasia in 28% of the cases. EDX microanalysis revealed that Si (94%) was the most frequently detected foreign element. SiO2 microparticles induced higher COL-1 expression; higher levels of proinflammatory cytokines, such as interleukin-6 (IL-6), IL-8, and transforming growth factor-ß, and increased MMP-2 activity in HGFs. CONCLUSIONS: There was a strong association between the presence of foreign material in the gingiva and white verrucous clinical lesions. In addition, the most common element in the foreign material was Si, and our in vitro findings demonstrate the importance of silica-mediated effects on gingival fibroblasts.