Study of external root resorption during orthodontic treatment in root filled teeth compared with their contralateral teeth with vital pulps

Llamas-Carreras JM, Amarilla A, Solano E, Velasco- Ortega E, Rodriguez-Varo L, Segura-Egea JJ. Study of external root resorption during orthodontic treatment in root filled teeth compared with their contralateral teeth with vital pulps. International Endodontic Journal, 43, 654-662, 2010. Aim To determine whether root filled teeth and those with vital pulps exhibit a similar degree of external root resorption (ERR) as a consequence of orthodontic treatment. Methodology The study sample consisted of 77 patients, with a mean age of 32.7 ± 10.7 years, who had one root filled tooth before completion of multi- band/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the root filled tooth and that in its contralateral tooth with a vital pulp. The student's t-test, anova and logistic regression analysis were used to determine statistical significance. Results The mean PRR was 1.00 ± 0.13, indicating that, in the total sample, there were no significant differences in root resorption in the root filled teeth and their contralateral teeth with vital pulps. Multivariate logistic regression analysis suggested that PRR was significantly greater in incisors (P = 0.0014; odds ratio = 6.2885, C.I. 95% = 2.0-19.4), compared to other teeth, and in women (P = 0.0255; odds ratio = 4.2, C.I. 95% = 1.2-14.6), compared to men. Conclusions There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root filled teeth and their contralateral teeth with vital pulps.