The influence of endodontic infection on periodontal status in mandibular molars.

The purpose of the study was to investigate the influence of an endodontic infection on periodontal probing depth and presence of furcation involvement in periodontally-involved mandibular molars. All first and second mandibular molars in 100 patients were selected if at least one was root-filled or had a possible periapical radiolucency. The sample consisted of patients from a referral population at a periodontal clinic which represented an adult population with a mean age between 50 and 60 years. For mandibular molars with periapical destruction at both roots, mean periodontal probing depth was significantly greater compared to teeth without periapical destruction. Horizontal furcation depths > or =3 mm were significantly more frequent at mandibular molars with periapical destruction. It is suggested that a root canal infection in periodontitis-involved molars may potentiate periodontitis progression by spreading of endodontic pathogens through patent accessory canals and dentinal tubules. In conclusion, an endodontic infection in mandibular molars was found to be associated with additional attachment loss in the furcation area, and may thus be considered to be one of several risk factors influencing the prognosis of molars in periodontitis-prone patients.