Identificación molecular y asociación causal de microorganismos presentes en lesiones periapicales refractarias al tratamiento endodóncico

Refractory apical periodontitis is a periradicular infection which persists in periapical tissues even though root canal treatment is performed. The infectious origin of persistent periradicular disease is controversial and an important challenge in dentistry. The traditional point of view regarding this theme defends that diseased tissues should be free from microorganisms or sparsely populated by them. However, there is evidence of presence of bacteria, viruses and fungi in periapical tissues of refractory cases. The aim of this investigation is to perform a case and control study to corroborate the presence of viable microorganisms and associate this presence as a causal factor. Through microscopy and molecular methods, this investigation was able to evidence the presence of microorganisms in 16 (80%) of 20 samples from refractory cases (0R: 136, IC 95%: 14-317) and in 1 (3%) of 35 samples corresponding to the control group (OR: 0,074, IC 95%: 0,0008-0.071). The results obtained in this study can associate the identified microorganisms as a causal factor of persistent apical periodontitis.