Table 2.

Complications and managements of REPs

Complications	Etiology	Prevention	Managements
Pain	Mechanical stimulation on periapical tissue	Keep accurate working length during the treatment Operate gently	For severe pain, effective dental drainage should be operated in time and the root canal disinfection should be performed again If the pain continues or aggravates, alternative treatments (apexification or tooth extraction) should be considered
	Compromised anesthesia effect	Use anesthetics with good permeability to improve the pain control
	Interappointment pain resulting from residual infection within the root canal, or re-infection of the tooth	Isolate tooth strictly by using rubber dam Copious canal irrigation and disinfection Seal the access cavity tightly between appointments
Tooth discoloration	Minocycline chelates calcium ions and incorporates into the dentin tissue as well as synthesizing oxidation products	Use low concentration of TAP and keep it below CEJ, right after sealing the pulp chamber with a dentin bonding agent Remove or replace minocycline with other antibiotics in TAP, such as clindamycin, amoxicillin and cefaclor	Internal bleaching Invasive intervention such as ceramic restorations could be the treatment of choice
	Blood ingredients permeate into the dentinal tubules and change the refractive index of the teeth	Place resorbable matrix over the blood clot, separating it from the barrier materials
	Porosities in calcium silicate–based materials entrap blood components and present high staining potential	Modify the composition of barrier materials by reducing the content of bismuth oxide or replacing it with zirconium oxide
Intra-canal calcification	A compound effect from multiple contributing factors which remains uncertain	–	Further treatment is usually unnecessary unless the tooth is symptomatic If symptoms are evident and show no sign of relief, RCT with guided access, micro-endodontic surgery or even an intentional reimplantation could be the treatment modality In the worst scenarios, tooth extraction could be considered
	Associated with ectopic bone formation and cementogenesis inside the root canals	–