Evaluation of the
results of periodontal treatment by means of digital subtraction of
radiographic images
Kulczyk T
Abstract
This
article presents general principles and a sample case of application
of digital subtraction of x-rays for objective evaluation of results
of treatment in dentistry.
Purpose: Evaluation of the results of
surgical periodontal treatment by means of digital subtraction of
radiographic images taken before and 12 month after surgery.
Material and methods: For evaluation of the results of guided
tissue regeneration treatment of deep bony defects digital periapical
x-rays were taken before and 12 months after surgery. Pairs of images
obtained during treatment were calibrated to equalize vertical x-ray
beam angulation followed by calibration to radiological contrast and
density. Next the comparison of images taken before and after
treatment was performed by means of special computer software
designed to subtract content of given images.
Results: Digital
subtraction showed that the radiological density in regions where
surgery was performed has decreased over a period of 12 months
meaning that the mineral content which is responsible for absorbing
x-ray photons has increased. Some local foci of subsurface
hypomineralization were found on subtractions images. These foci
couldn’t be detected clinically because hypomineralization was
taken place within bone.
Conclusions: Digital subtraction of
x-rays taken before and after surgery treatment is detailed and
objective method of evaluating results particularly when changes of
surface and subsurface bone mineralization around teeth must be
examined.
Key words: digital subtraction, periodontal treatment, guided tissues regeneration.