Patient’s age and extent of coronal and root destruction predict root canal treatment subsequent to after a full-cast crown: Which clinical factors are predictive of root canal treatment following full-cast crowns?

Design A case–control study was carried out at the University of North Carolina School of Dentistry in the US.Participant selectionDental charts from the university's dental clinical were audited for patients who had a single-cast crown between 1 January 1998 and 31 December 2002. Cases were defined as individuals who underwent root canal treatment at some time after the insertion of a single-cast crown up to 1 July 2004. The control group consisted of people who did not have root canal treatment after the insertion of a full-cast crown.Data analysisA list of 24 clinical factors was compared between groups (Table 1). Multiple logistic regression analysis was used to determine which preoperative nonprocedural factors were predictive of root canal treatment subsequent to a full-cast crown.ResultsA total of 6612 single-cast crowns (cast metal or porcelain fused to metal) were inserted during the 5-year period of interest. Of these, 5743 crowns, identified from 3357 patients' records (ie, the study subjects), were determined not to have undergone root-canal treatment prior to full-cast crown restorative treatment. Ninety-two subjects were initially determined to be eligible cases; ninety-two subjects were also therefore randomly selected from the remaining 3265 subjects to make up the control group. Twenty-six of the cases and 21 members of the control group were excluded because of incomplete records. The final case and control groups comprised 66 and 71 subjects respectively. Only subjects' age at the time of restorative treatment and their post-cementation tooth sensitivity was statistically significantly different between the two groups (P<0.05). Multiple logistic regression determined the statistically significant (P<0.05) predictors of case status: these were a patient's age and also the subgroup to which they were allocated according to the extent of pre-operative coronal and root destruction, on the basis of the restorative core size (more than three restored surfaces; Table 2).ConclusionThe age of a patient and the extent of coronal and root destruction can be used to predict the future need for root canal treatment on teeth for which a single-cast crown is planned. © 2006 EBD.