_______________________________ DCA05DR Dental Radiation Health, Safety, and Protection, 3rd Edition
INTRODUCTION
HISTORICAL BACKGROUND The discovery of x-rays, a singular event in history, occurred by accident. On November 8, 1895, while experimenting with a Crookes tube in his darkened physics laboratory in Germany, Wilhelm Conrad Roentgen noticed that a plate coated with a fluorescent material on a nearby bench was glowing. Soon he realized that he had uncovered something altogether new, an “x” or “unknown” light or ray. Roentgen thoroughly investigated this new energy form and described many of the properties of the x-ray. He presented his findings to the scientific community, and in early 1896, he produced and published a radiograph which showed his wife’s hand with a metal ring on one of the fingers (Yap, 2024). This discovery began a revolution in medical and dental diagnostics. Several months after Roentgen’s discovery, x-ray research- ers, physicians, dentists, and patients began to experience skin effects, hair loss, and anemia. In 1902, the first case of radiation-induced skin cancer was reported (Bennardo et al., 2021). In 1904, Clarence Dally, a scientist who had extensive work with x-rays, died from skin cancer and was the first known x-ray fatality. Although there was an increased interest in the use of x-rays for medical purposes, the scientific community became concerned about the correlation between the use of x-rays and leukemia in the early 20th century (Vardeu et al., 2020). The harmful effects of radiation were poorly under- stood at the time, and many early pioneers suffered ill effects from overexposure to radiation. The years since then have seen significant improvements in equipment, imaging techniques, dose reduction, and radiation safety and protection measures. Many agencies exist to regulate ionizing radiation and minimize the exposure of patients and operators during radiographic examinations. For example, the National Council on Radiation Protection and Measurements (NCRP) and the International Commission on Radiological Protection (ICRP) have estab- lished guidelines to limit the amount of radiation received by both occupationally exposed persons and the general public. The ICRP provides recommendations and guidance to the public on all aspects of protection from ionizing radiation. In addition to the NCRP and ICRP, many organizations make recommendations and policies to govern the use of ionizing radiation. For example, the International Commission on Radiation Units and Measurements makes recommendations on radiological units of measurement. The NCRP develops concepts about radiation protection and dose limits (DLs). The Occupational Safety and Health Administration (OSHA) is responsible for occupational radiation protection policies. In addition, each state has statutes that regulate radiographic equipment, equipment inspection, and the credentialing of persons who work with radiation.
“Researchers link dental x-rays to brain tumors.” — American Cancer Society, 2012; study referenced in Rundell (2021)
The preceding quote presents dental x-rays in an ominous fashion and suggests a definitive etiologic link between den- tal x-rays and the development of brain tumors. However, the study titled “Dental X-rays and Risk of Meningioma” by Claus, Calvocoressi, Bondy, Schildkraut, Wiemels, and Wrensch, published in 2012, relied upon data collected from Dental Radiation Health: Safety and Protection in the Digital Age, 2nd Edition : x-rays taken decades ago when higher doses of radiation were utilized and patient recollection of the quantity of x-rays taken (Rundell, 2021). Dental patients and dental professionals alike will recognize this headline. The biologic risks of radiation exposure associated with dental radiographic examinations have been a recurring topic in the national news media. Several published but controversial studies have suggested possible associations between dental radiographic examinations and conditions such as meningiomas (Auvinen et al., 2022) and thyroid cancer (Kosar & Koundal, 2022; Hwang et al., 2020). The public, including the patients who dental professionals treat in their practices, becomes more alarmed with each successive report. Without question, x-radiation is harmful; it is a known carcinogen. There is considerable evidence in the literature that ionizing radiation increases the risk of certain types of cancers, including leukemia and skin, lung, and thyroid cancers, to name a few (American Cancer Society, 2022). However, what is not known with certainty is the effect that low-dose diagnostic imaging exposures have on the human body. Although the risk of cancer from dental radiographic examinations is thought to be negligible, no radiation exposure is considered to be risk-free, and the effects of radiation are cumulative. For these reasons, radiation safety remains a top concern for the general public, and the dental professional needs to stay up to date on the latest research and current thinking on radiation safety and protection. The purpose of this course is to review the biologic effects of radiation, the methods used in radiation measurement, and the potential sources of radiation exposure. This basic-level course will discuss radiation safety and protection measures for both patients and dental healthcare workers. Perhaps most important, this course will prepare all dental professionals— including dentists, dental hygienists, and dental assistants—to accurately respond to patient questions and concerns about radiation safety in dentistry.
85
EliteLearning.com/Dental
Powered by FlippingBook