Root resorption identification and accuracy of two digital radiographic systems

Aim: to evaluate the ability of two digital systems, as compared to conventional periapical radiographic method, to identify and measure accurately the presence and size of simulated root resorptions in vitro. Materials and methods: Thirty human permanent teeth extracted because of being unrestorable, but with sound roots with lengths varying from 14 to 18mm, were used in this study. Teeth were sterilized in autoclave roots were measured in a digital pachymeter in the mesio-distal aspect of the cervical third as thin (<4.5mm) or thick (4.5mm and over). Cavities were prepared with #2, 4 and 6 burs, being 1for each root, at the external cervical area, simulating resorption. Roots were then distributed to the groups with equal number of thin and thick roots, and equal number of root resorptions (n=10) for each group. Then the roots were inserted in an alveolus of a mandible to standardize the bone interference, and submitted to the Sens-A-Ray (Reagan Medical System, Sundsvall, Sweden) and Schick CDR (Schick Technologies Inc., Long Island, NY, USA) systems, and to a control conventional periapical radiographic technique using Ultra – Speed film (Kodak, Rochester, USA). Three experimented observers, blinded about the original measure, detected and measured the root resorptions, and compared to the actual resorption sizes. Results: all the methods were able to reveal the resorptions. The Bland-Altman multiple comparisons technique showed little dispersion of the measures of all the techniques when compared to the original resorption measure. The Sens-A-Ray system had little greater dispersion values than Schick CDR and the radiographic method. Conclusion: all methods were able to detect root resorption, but Sens-A-Ray showed the least reliable measurements.