Foram avaliadas as técnicas radiográficas dentárias intra (TIB) e extrabucal (TEB) em 50 cães com doença periodontal, no intuito de padronizar os procedimentos de diagnóstico dessa síndrome. A TIB revelou que 16 animais não apresentaram lesões ósseas visíveis, enquanto a TEB apontou que 39 pacientes foram negativos para as mesmas lesões. em resumo, a TIB foi mais eficaz na detecção de sinais radiográficos, especialmente as chamadas lesões finas, que a TEB, sendo a técnica de escolha na síndrome periodontal.The intra (IOT) and extraoral (EOT) dental radiographic techniques in 50 dogs with periodontal disease were compared to standardize the most appropriate procedure for accurate diagnosis of abnormalities that occur in this syndrome. For IOT, 16 animals showed no visible radiographic lesions, whereas in EOT, 39 patients were negative for the same radiographic lesions. For incisor and canine teeth, IOT presented the highest sensitivity of lesion detection, while there was no significant difference for the premolar and molar teeth group. It is concluded that IOT is more effective in detecting radiographic signs (especially the so-called thin lesions) than the EOT and should therefore be the technique of choice in the periodontal syndrome.