牙科X 光片是診斷和治療口腔疾病(如齲齒，牙周病等)有用和必要的工具。儘管與牙科射線照相相關的曝露相對較低，但任何放射學檢查程序都應正當化(justification)和最適化(optimization)，將輻射風險保持在合理抑低(aslow as reasonably achievable, ALARA)。放射設備及技術的發展對於牙科放射線攝影中減少患者輻射劑量有顯著的影響，除了長方形準直儀(rectangular collimation)、快速底片、長錐體(long cone)外，使用甲狀腺鉛頸圈(thyroid collars)防護用具、直流電X 光機(Direct Current, DC)及適當的峰值千伏電壓(kilovoltage peak, kVp)等亦有助於降低病患輻射劑量。為了瞭解牙醫師對於輻射防護的做法，此研究蒐集402 位牙醫師於口內放射線攝影時，病人配戴鉛頸圈之比例，同時調查DC X 光機及使用kVp 之數據。調查結果顯示，42.5%牙醫師使用甲狀腺鉛頸圈、27.9%牙醫師使用DC X 光機，50.7%牙醫師使用峰值千伏電壓為60 kVp、4%牙醫師使用峰值千伏電壓為65 kVp、45.3%牙醫師使用峰值千伏電壓為70 kVp。調查數據中，所有X 光機之kVp 皆符合美國輻射防護與度量委員會(National Council on Radiation Protection and Measurements, NCRP)輻射防護建議原則，但超過一半的開業牙醫師未使用甲狀腺鉛頸圈，且使用DC X 光機的比例偏低。為了減少任何不必要的輻射曝露，應嘗試透過輻射防護繼續教育課程，提高牙醫師使用甲狀腺鉛頸圈防護用具比例，並使用減少病患輻射劑量的相關儀器設備。

Dental X-rays are crucial tools in the diagnosis and treatment of oral diseases such as dental caries, periodontal diseases, etc. Although exposure associated with dental radiography is relatively low, there should still be justification and optimization to keep radiation doses at a reasonable level (as low as reasonably achievable, ALARA). Advancements in equipment and techniques have had a considerable impact on lowering the amount of radiation used in dentistry. Rectangular collimators, faster film speeds, long cones, direct current (DC) X-ray machines, thyroid collars, and appropriate peak voltage (kVp) are all ways to reduce radiation doses for patients. To learn of the ways in which dentists utilized radiation protection, this study collected information supplied by 402 dentists in private practices on their various methods of radiation management. According to the survey results, 42.5% of dentists used thyroid lead collars, 27.9% of dentists used DC X-ray machines, 50.7% of dentists used a peak voltages of 60 kVp, 4% of dentists used peak voltages of 65 kVp, and 45.3% of dentists used a peak voltage of 70 kVp. All participants had the kVp on their X-ray machines set within the recommendations of the National Council on Radiation Protection and Measurements (NCRP). Although some dentists did adhere to safety standards, over half the practicing clinicians did not use a thyroid collar and there was no widespread adoption of DC X-ray machines. In order to reduce the amount of unwanted radiation, continuing education programs should aim to make safety equipment more appealing. An increase in the proportion of dentists who use more effective safety measures will help in reducing radiation doses in patients.