Radiation dose reduction using novel size 1 and size 0 rectangular collimators in pediatric dental imaging.

Objectives: Commercial intraoral rectangular collimators are available for collimating to size 2 image receptor. The benefits of reducing the x-ray beam to match the area of the image detector in adult intraoral radiography are endorsed internationally. However, in pediatric dentistry the image receptor can be further decreased to size 1 and 0.

Method And Materials: For this study size 1 and 0 rectangular collimators were fabricated using 1.65-mm lead sheets (Rotometals). The custom-fabricated collimators were fixed to the plastic body of a Rinn (Dentsply) Universal Collimator attachment. Aperture sizes were extrapolated based on the active imaging area of size 1 and 0 digital image receptors. A dose area product (DAP) measuring device was used to determine the change in radiation absorbed dose as a function of the imaging field of view.

Results: DAP measurements were evaluated in the 31.7 cm2 conventional round collimation, Rinn 12.0 cm2 Universal rectangular collimator, and in the manufactured size 1 (8.25 cm2) and size 0 (5.72 cm2) rectangular collimators. The size 1 collimator had a 32% DAP reduction from the size 2, and a 53% reduction for the size 0.

Conclusion: Size 1 and size 0 rectangular collimators can be independently manufactured and utilized in pediatric dentistry. This study suggests that a considerable radiation dose reduction is possible in pediatric intraoral imaging when using the size 1 and 0 matched collimation. Since the pediatric population is vulnerable to radiation exposure, any measurable reduction has a potential for long-term health benefits and is therefore clinically significant.