Post-treatment Pain After Cementing an Indirect Restoration at the End of a Root Canal Treatment: Clinical Trial

Introduction: International consensuses on restoration of the root filled teeth recommend early placement of indirect cuspal coverage in posterior teeth. Some classical schools of thought have argued that after endodontic treatment there may be slight periapical inflammation that may lead to over-occlusion, this causing postoperative pain, so that it is preferable to leave the tooth in slight under-occlusion and defer the definitive restoration. Recent studies question this theory and propose a restoration with normal occlusion at the same time of root canal treatment, if possible. Even in these cases, the placement of a full coverage indirect restoration is postponed due to the material impossibility of fabricating it with traditional systems. Modern computer assisted design (CAD)/ computer assisted manufacture (CAM) dental systems make it possible to produce and place such restorations in the same session as the endodontic work is completed. This greatly reduces chair time and the number of visits, while increasing the strength of the tooth right from the start. This is why in this study we compare postoperative pain in two groups of endodontically treated teeth, one in which the indirect CAD/CAM restoration is performed on the same day as the endodontic treatment, and the other in which it is postponed for a week, leaving the tooth in underocclusion.

Background and current status of the subject:

The main reason for root filled teeth loss is restorative failure, which accounts for 60% of all failures. This is followed in order of frequency by periodontal failure, which accounts for 30% of the total. Purely endodontic failure accounts for only 10% of all failures. On the other hand, we know about the high success rate and even higher survival rate of endodontically treated teeth. In a follow-up study of 1462936 endodontic procedures, an 8-year survival rate of 97% was observed. It is accepted that the success, a more demanding criterion than survival, of these root canals ranges between 85 and 90%. Given that most failures occur in the first two years, and given, as already mentioned, that the main cause of this failure is inadequate reconstruction, it has been advised to proceed to definitive restoration of the tooth with an indirect veneering material, and as early as possible.

Modern CAD/CAM systems, and especially the CEREC system, make it possible to produce high-quality chairside indirect restorations in a short time. This makes it possible to place the indirect restoration in a single session. With an appropriate strategy, it is possible to make impressions of the restoration before the root canal treatment is completed. Thus, while the treatment is being completed, the restoration can be fabricated and immediately placed in the tooth without removing the rubber dam isolation at the same visit as the root canal treatment is completed.

After root canal treatment it is possible that periapical inflammation may occur, leading to some overeruption of the tooth. It has been said that this can be a cause of postoperative pain. Thus, there are authors who question the performance of the definitive full-volume restoration on the same day of endodontics, preferring to leave the tooth with a provisional restoration in infraocclusion. However, the literature is not clear regarding a possible increase in postoperative pain in the case of leaving a definitive restoration at full volume, while questioning the relationship between postoperative pain and the type of restoration on the day of endodontics.