The effect of the gap between the post restoration and the remaining root canal filling on the periradicular status in a Turkish subpopulation.

OBJECTIVE The aim of this study was to evaluate whether the gap between the post restoration and the remaining root canal filling had an impact on the periapical health of endodontically treated teeth in a Turkish subpopulation. STUDY DESIGN Digital panoramic radiographs, evaluated for this cross-sectional study, were randomly selected from files of patients who attended to Yeditepe University, Faculty of Dentistry, between June 2007 and December 2008. The total number of teeth with endodontic posts and crowns was 407. Two observers assessed the radiographs and evaluated the quality of root canal filling and the gap between the root canal filling and the post restoration. Periapical status of the teeth was assessed by the Periapical Index (PAI) scores. Only the teeth with a minimum of 5 mm apical root canal filling that was classified as "good endodontic treatment" were included in the study. Teeth that had no root canal filling, poor endodontic treatment, or less than 5 mm remaining root canal filling beyond post restoration were not assessed. Chi-square test was used for statistical analysis and significance level was established at 5%. RESULTS In cases with good endodontic treatment, there were 207 teeth that had no gap between the remaining root canal filling and the post restoration. In this group, 135 (65%) teeth had healthy periapex and 72 (35%) teeth showed signs of apical periodontitis. There were 81 teeth that had a gap between the remaining root canal filling and the post restoration. Of these teeth, 69 (85%) had periapical pathosis; however, only 12 (15%) teeth had healthy periapex. CONCLUSION Statistical analysis revealed that the success rate of good endodontic treatment was significantly affected by the gap between the post restoration and remaining root canal filling (P < .001).