Authors: Miles DA, Langlais RP; National Council on Radiation Protection and Measurement.
Title: NCRP report No. 145: New dental X-ray guidelines: their potential impact on your dental practice.
Journal: Dent Today
Date: Sep 2004
Citation: 23(9):128-34
Category: Radiology and Imaging
Evidence-based Ranking: 5
Purpose/Objectives: To summarize the newest dental X-Ray guidelines from the National Council on Radiation Protection and Measurements’ (NCRP) report No.145, released in December 2003, and to alert dentists to the potential impact on their office radiographic procedures. Discussion: The NCRP is a non-profit organization that periodically assesses new technology and radiation safety practices to make recommendations about radiological procedures bases on available scientific data. Report No. 145 addresses several items that apply to day to day practices involving radiographs in the dental office. “It is important for each dentist to realize that, based on past reports issued by NCRP, this report will be cited as the current ‘standard of practice’ for all x-ray procedures in the dental office. Practitioners must comply if they want to eliminate or at least reduce their risk of potential liability.” Items reviewed in the report include: 1) The use of leaded aprons on patients shall not be required if all other recommendations in this report are rigorously followed”; 2) Thyroid shielding shall be provided for children” and “should be provided for adults, when it will not interfere with the examination.” 3) “Rectangular collimation of the beam shall be used routinely for periapical radiography. Each dimension of the beam, measured in the plane of the image receptor, should not exceed the dimension of the image receptor by more than 2% of the source-to-image receptor distance. Similar collimation shall be used, when feasible, for interproximal (bitewing) radiography.”; 4) “Image receptors of speeds slower than ANSI speed Group E films shall not be used for intraoral radiography. Faster receptors should be evaluated and adopted if found acceptable.” “For extraoral radiography high speed (400 or greater) rare earth screen-film systems or digital-imaging systems of equivalent or greater speed shall be used.” 5) Regarding cephalometric images, “practitioners need to remember that all structures recorded on the image need to be interpreted for evidence of disease or injury as well as for cephalometric analysis.” This may prompt practitioners to obtain a report from a board-certified oral and maxillofacial radiologist, the ADA’s newest recognized dental specialty; 6) Dental practitioners who sight develop (“reading” wet x-ray film at the time of a procedure) should note the following: “Dental radiographic films shall be developed according to the film manufacturer’s instructions using the time-temperature method.Sight development shall not be used.”; 7) Practitioners designing new offices or remodeling existing locations will need shield protection to be provided by a qualified expert. 8) Dentists must examine their patients prior to ordering or prescribing x-ray images (this is not a new guideline); 8) Nine new recommendations for image processing of conventional film are outlined; the author suggests considering switching to digital imaging because of all the steps necessary to comply with the new recommendations.

Authors’ Conclusions: Every dentist must now re-examine his or her radiographic services, protective equipment and receptor selections to ensure they are practicing within the accepted standards. This report appears to make a strong case for dentists to adopt digital imaging systems and receptors, especially if they wish to avoid some fairly dramatic changes to the radiation protection program, receptor speeds filtration and chemical processing. Reviewer’s Comments: This article was a good review of NCRP report No.145 and addresses specific things dental practitioners should be doing to be in compliance with these new standards.