Eight-Year Retrospective Study of the Critical Time Lapse between Root Canal Completion and Crown Placement: Its Influence on the Survival of Endodontically Treated Teeth

By Pratt I , Aminoshariea A, Montagnese TA , Williams KA, Khalighinejad N, Mickel A

Date: 05/2017
Journal: JOE

Purpose: The purpose of this study was to investigate the effects of factors associated with various coronal restorative modalities after root canal treatment (RCT) on the survival of endodontically treated teeth (ETT) and to assess the effect of time lapse between RCT and crown placement after RCT to form a tooth loss hazard model

N= 882 Posterior teeth.

Inclusion and exclusion criteria:

-Pre and postoperative radiograph present.                                              

X    Loss of follow up ü

-Restorable ETT that received coronal restoration within 24 months  

X    No information regarding coronal restorations

-Periodontally sound teeth                                                   

  Periodontally compromised teeth 

-Acceptable quality of RCT                                                                         

  X   Mishaps including perf. and file separation

Materials and methods:

•Computerized analysis was done for all patients who received posterior RCT from 2008 to 2016 in the graduate endo department of CWRU school of dental medicine.

•Collected information included patient’s age, type of teeth, dates of NSRCT, type of coronal restoration, date of coronal restoration placement, and date of extraction.

•Survival was defined as the presence of ETT in the oral cavity by the end of the study. ( Jan 1st,  2016 )

•Failure was defined as extracted ETT.

Distribution of collected data:

•441 teeth (50%) received a full coverage crown after RCT.

•198 teeth (23%) received composite/amalgam buildup restorations.

•243 teeth (27%) never received a final restoration after RCT.

•ETT received crown after RCT were divided into 2 groups: receiving crown before 4 months and after 4 months following RCT.

Most highlighted results:

•777 teeth (88.1%) survived to the end of the study (January 1, 2016).

The type of restoration after RCT significantly affected the survival of ETT.

•ETT that received composite/amalgam buildup restorations were 2.29 times more likely to be extracted compared with  ETT that received crown. •ETT that did not receive any  permanent restoration were 4 times more likely to get extracted compared with those that received a full coverage crown.

Time of crown placement after RCT significantly correlated with survival rate of ETT.

•ETT that received a crown more than 4 months after RCT were extracted at 3 times the rate of teeth that received a crown within 4 months after RCT. 

Clinical significance:

Timing of the crown placement after root canal treatment can significantly affect the survival rate of endodontically treated teeth.