Clinical Strategies for Management of Cases with Refractory Apical Periodontitis

Abstract

The present study consists of two parts. In the first part 20 subjects with refractory apical periodontitis were investigated for the presence of Enterococci and/or Actinomyces using conventional culturing confirmed by PCR. Antibiotic susceptibility testing was also caried out to assess the sensitivity of the bacteria to three different antibiotics. The effect of antibiotics used as ICM was assessed microbiologically as well as clinically. Cases which failed to respond to this clinical strategy were swaped in the second part of the study where root end surgery was done with retrograde filling application. Radiographic follow up was done to assess healing. Periapical lesions excised during surgery were histopathologically identified in order to find out if there was a correlation between healing and the nature of the lesion.

The results showed: • Prevalence of Enterococci as the pathogen causing refractory apical periodontitis (90%) than Actinomyces which showed in only 25% of the studied cases. • Actinomyces was not the cause of the refractory behaviour of the case except when present in a highly significant count, Enterococci on the other hand could cause resistance even in less amounts. • No consistent sensitivity was found for a certain pathogen to a certain antibiotic. • Healing occured after ICM application in 99.5% of cases with Enterococci and in 92.2% of cases with Actinomyces. • Significant increase in radiodensity after periapical surgery occured consistently over the follow up intervals of the study. • 85% of the periapical lesions enucleated during surgery were shown to be granulation tissue whereas, only 15% were inflammatory cysts. • No difference in healing rate was found between cases with granulation tissue and others with inflammatory cysts. Based on the results of this study, the following conclusions could be drawn: 1. Enterococci is generally more virulent than Actinomyces. 2. Antibiotic susceptibility test should be caried out individually for each case as there is no consistent sensitivity for a certain pathogen to a certain antibiotic. 3. Prevalence of apical cysts is much less than apical granulomas. 4. A direct relation between radiodensity and time in relatively short follow-up periods.