Reabsorções radiculares externas em dentes permanentes reimplantados: determinantes clínicos e epigenéticos
Daniela Augusta Barbato Ferreira
Inflammatory external root resorption (IERR) is a pathological process defined as the progressive loss of mineralized root tissue, dentin and cementum, resulting from the combination of damage to the protective layers of the root surface and the presence of microorganisms within the root canal. Several clinical and experimental studies have demonstrated the role of demographic and clinical factors related to the management and treatment of avulsed teeth in the etiopathogenesis and evolution of IERR after replantation. However, few studies have evaluated the influence of the patient's genetic and immunological profile on the healing patterns after dental replantation. The present study aimed to evaluate (1) the interaction of possible prognostic factors for the development of the IERR after replantation of permanent mature teeth, as well as to investigate (2) the role of epigenetics in posttraumatic IERR immunomediated processes. Case records and radiographs of 581 mature replanted permanent teeth from 427patients (mean age 12.6 years) were evaluated for the presence and extension of IERR and tested for their association with age and clinical factors related to the management and acute treatment of the avulsed tooth. IERR was diagnosed in 469 teeth (80.7%) of the sample and a multinomial regression model revealed that an increase of time elapsed from replantation until pulpectomy increased the odds of severe IERR while the raise in the patients ‘age at trauma decrease the odds of severe IERR. In addition a significant quantitative interaction between these two covariates was found since the effect of time until pulpectomy was attenuated by the increase of the patient's age. This is an unprecedented result and represents a relevant contribution by pointing out that these two covariates should be considered together during clinical decision making, emphasizing the greater vulnerability of the younger patient. For epigenetic study, the DNA methylation pattern of 22 immune response related genes was quantified using EpiTect Methyl II Signature Human Cytokine Production PCR Array in a pooled sample of 08 root fragments presenting with IERR and compared to a pool of healthy bone tissue collected during the extraction of impacted teeth from 06 patients. Results revealed a higher methylation level of the FOXP3 gene promoter region in IERR (65.95%) compared to the normal bone group (23.43%).This is the first evidence of the possible participation of epigenetic events in IERR modulation and it is speculated whether the observed methylation pattern could be altered due to the presence of endodontic infection.