Purpose:  to evaluate if retreatment resulted in improved standard of root-fillings and follow cases clinically and radiographically to determine effect on PA tissue

Methodology:

•N = 410 patients (170 male, 240 female): total of 660 roots

•Sample divided to two groups according to presence of PARL radiographically:

G1: no PARL but visible technical shortcoming of the present RCT (n = 351) and teeth were retreated for preventive reasons (short RCT, voids) regardless of age of the treatment

G2: PARL present and RCT is at done least 2 years ago (n = 309)

•All procedures were carried by students and performed using RD isolation. G1 completed in 1 session, G2 completed in 3-4 sessions and intracanal medicament placed (5% iodine potassium or Ca(OH)2)

•In cases with PARL, bacterial sampling was collected and sampled and only if negative the root canal will be filled. 

•Obturation using resin and gutta-percha in chloroform using multicone technique. Immediate post-op Radiographs taken (2 angulations). Considered satisfactory if working length attained and complete seal obtained.

Follow up: 2 year recall followed by another recall 2 months later, clinical and radiographic examination for presence of PA lesion, largest width present, changes in the size of PA lesion , length of filling from apex, seal and presence of lumen apical to root filling. 

Most highlighted Results:

•81% of cases were prepared and obturated closer to the apical foramen •94% of cases with no PARL did not develop PA lesion, and 48% of pre-op PARL showed healing

Clinical significance

Consider NSReRCT even in absence of PARL in case of low quality RCT

Retreatment can potentially increase the quality and length of obturation