Cone-beam computerized tomographic, radiographic, and histologic evaluation of periapical repair in dogs' post-endodontic treatment.
OBJECTIVE
To evaluate the periapical repair after root canal treatment in the teeth of dogs using CT and conventional radiography and to compare these findings with the gold standard microscopic evaluation.


METHODS
The animals were divided into three groups according to endodontic treatment performed: Group 1, single-visit endodontic treatment in teeth without apical periodontitis; Group 2, single-visit endodontic treatment in teeth with apical periodontitis; and Group 3, endodontic treatment in teeth with apical periodontitis using calcium hydroxide as a root canal dressing. Group 4 consisted of teeth with apical periodontitis not submitted to root canal treatment and Group 5 consisted of healthy teeth without periapical disease. Radiographic, tomographic, and microscopic evaluations were performed by blind examiners. At 180 days experimental time, CT and radiographic measurements of periapical disease were compared with the gold standard microscopic measurement using intraclass correlation coefficient. Intergroup comparisons considering different methods of periapical lesions measurement or different clinical protocols of root canal treatment were performed by Kruskal Wallis test followed by Dunn. Integrity of lamina dura, presence of radiolucent areas, and presence of root resorption were analyzed by Fisher's exact test.


RESULTS
There was discontinuity of the lamina dura and CPD in all teeth from Groups 2, 3, and 4 evaluated by tomography and radiography 45 days after CPD induction. Radiographically, 180 days after root canal treatment, there was no periapical lesion in teeth from Groups 1 and 3, different from groups 2 and 4 (p < .05). The highest reduction in the CPD size was observed on Group 3 (p < .05). According to the tomographic results, there was decrease of the size of the CPD on Group 3 but not on Groups 2 or 4. However, in all groups the periapical lesions presented larger mesio-distal extension if compared with radiography, both 45 days after CPD induction and 180 days after root canal treatment. At 180 days, CT measurements were closely related to microscopic results (ICC = 0.95) differently from radiographic evaluation (ICC = 0.86).


CONCLUSIONS
CT Scan evaluation of periapical repair following root canal treatment provided similar information than that obtained by microscopic analysis, whereas radiographic evaluation underestimated the size do periapical lesion.
de Paula-Silva
Francisco Wanderley Garcia
FW
Department of Pediatric Clinics, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil. franciscogarcia@forp.usp.br
Santamaria
Milton
M
Leonardo
Mário Roberto
MR
Consolaro
Alberto
A
da Silva
Léa Assed Bezerra
LA
D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000818:Animals; D054893:Cone-Beam Computed Tomography; D004285:Dogs; D008853:Microscopy; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging* / Q000628:therapy*; D011829:Radiation Dosage; D011861:Radiography, Dental / Q000379:methods*; D012390:Root Canal Therapy / Q000379:methods*; D012391:Root Resorption / Q000000981:diagnostic imaging; D016037:Single-Blind Method; D014962:X-Ray Film