Success rate of endodontic treatment of good or poor quality in teeth with good or poor coronal restorations

Endodontic treatment	Coronal restoration	n	Failure	Success	Success in percent
GE	GR	364	70	294	81%*
GE	PR	142	41	101	71%*
PE	GR	299	131	168	56%*
PE	PR	196	85	111	57%*

GE = Good Endodontics; PE = Poor Endodontics; GR = Good Restoration; PR = Poor Restoration. * The difference between the success rate with Good Endodontics and Poor Endodontics was statistically significant (P<0.0001) regardless of the quality of the coronal restoration (GR or PR).

Ray HA, Trope M. 1995 Tronstad L, Asbjørnsen K, Døving L, Pedersen I, Eriksen HM. 2000