Prognosis of large cyst-like periapical lesions following nonsurgical root canal treatment: a clinical review

Aim To evaluate clinically and radiographically the long-term clinical outcome of nonsurgical root canal treatment using calcium hydroxide in teeth with large cyst-like periapical lesions. Summary A total of 42 mature anterior teeth with large periapical lesions ranging in size from 7 to 18 mm in diameter were included in this study. Fluid samples from the lesions contained cholesterol crystals, which were identified by light microscopy. After adequate draining, the teeth were treated endodontically using calcium hydroxide as the intracanal medicament. All cases were followed up for a period of 2-10 years. Complete healing was observed in 73.8% and incomplete healing in a further 9.5% of cases. Key learning points Root canal treatment using calcium hydroxide as an antibacterial dressing was successful in healing large cyst-like periapical lesions. This study suggests that the size of a periapical lesion is not a major determining factor in the decision to perform conventional root canal treatment or surgical removal of the lesion. Even large cyst-like periapical lesions containing cholesterol crystals can heal following nonsurgical root canal treatment.