High Purity Aluminum Stepwedge

New Washington State rules for radiation safety were passed in July, 2008. 

On January 1, 2009 a letter and a guide was sent to Washington State dentists informing them of the new requirements. To view the “Washington Dental Fillm Processing Quality Assurance, A Guide to Implementation”, click here. To view the introduction letter, click here.

WAC 246-225A-110 requires that dentists conduct an acceptable quality assurance program that includes weekly tests on the performance of dental film processing to ensure consistent x-ray quality. The requirement actually went into effect on January 1, 2010, after which time the state inspectors will be checking for compliance. To view the Washington State law, click here.

Why use a stepwedge?

A High Purity Aluminum Stepwedge is a quick, inexpensive quality assurance test for clinical dental radiography. This allows you to evaluate the performance of the X-ray machine and the processing system. Step-wedges can also be used in the calibration of x-ray machines, and are used as a quality assurance test in monitoring the film processing used in dental radiography. Step-wedges are also used for measurement and analysis of x-ray beam quality. A manufactured aluminum stepwedge produces images of consistent quality. While not a requirement when using digital sensors; a stepwedge would provide the invaluable benefit of being able to monitor the performance of the x-ray machine and the digital sensors.

What are test X-rays?

Test X-rays are X-ray images that should be taken on a regular basis using a high purity aluminum stepwedge and bitewing exposure factors.A full range of grey should be visible – one end of the X-ray should be light grey and the opposite end should be almost black. 9 lines of grey should be clearly visible.

X-ray Quality Assurance Program

When starting a quality assurance program with a step wedge; it is necessary to first take a reference x-ray image. Place the step wedge over a film or sensor and position the x-ray field over the step wedge. Record the date, operatory, X-ray machine, kVp, mA, exposure time, Source-to-Image Distance, and developing time.

This information will be necessary to conduct this test in the future. Take an exposure (and if using film, develop the film as usual). Save this image as the reference image for that x-ray machine.

Once a month or any time that you suspect that there may be a problem with your x-ray system, create another image in the same manner as described above. Compare this image to the reference image. If you notice a change in density of “2 steps”, you are alerted that there is a problem and corrective actions should be taken before your radiographs deteriorate in diagnostic quality.

Margraf Dental’s Stepwedge

Our high purity aluminum stepwedge is manufactured from aircraft grade, 6061 97.9% pure aluminum. When measured with digital-subtraction radiology, the 6061 97.9% pure aluminum had the most consistent density throughout the raw material.

Our high purity aluminum stepwedge measures 1 1/2″ x 3/4″ (38mm x 19mm) and will conveniently fit on periapical film or sensor. Our #90-951 is 9mm thick with 9 – 1.0mm increments or steps. Also available upon request are other variations of thickness or amount of increments (steps). We also manufacture larger step wedges that can be used to measure or test the quality of a Pan-Ceph unit.

Margraf Dental’s Shielded PID’s

WAC 246-225A-080(1)(d) requires for all dental radiography, that shielding be included in the beam-limiting device or position-indicating device (PID).

Margraf PID’s (open end lead-lined cone) are designed to exceed all federal and state requirements. Our PID’s are completely lead lined to reduce scatter and secondary x-radiation, yet are light in weight.

To view our complete line of shielded PIDs click here.

The benefit of using shielded PIDs

A shielded PID will reduce secondary or scatter radiation. Secondary radiation must be considered when taking X-rays. The scattered radiation will create a loss of contrast and definition. Secondary radiation comes from radiation exiting the side of the PID, bouncing of other objects in the room, and back to the film. This scatter radiation will reduce the diagnostic quality of the x-ray.