Evaluation of an alternate pulpotomy technique performed in carious permanent mature mandibular molar teeth with symptoms indicative of irreversible pulpitis: A randomized clinical trial

Mature permanent teeth with symptomatic irreversible pulpitis have traditionally been managed with non-surgical endodontic therapy (NSET) . This was based on the concept that the entire pulp would degenerate in totality (strangulation theory) . However, with the enhanced understanding of pulp pathophysiology, this conception has changed. The current theory puts forward the concept that the pulpal inflammatory changes occur in stages with the inflammation occurring from coronal to radicular pulp denoting that vital pulp tissue can be expected in the radicular part of the teeth with irreversible pulpitis . Hence there has been a paradigm shift in the management of teeth with symptomatic irreversible pulpitis from NSET to pulpotomy. It has been performed widely with a high success rate. Pulpotomy procedure can be full or partial pulpotomy. According to European Society of Endodontics,  full pulpotomy is defined as complete removal of the coronal pulp and application of a biomaterial directly onto the pulp tissue at the level of the root canal orifices. The  average success rate of full pulpotomy is 95%. Whereas, partial pulpotomy is defined as the removal of the coronal 2-4 mm of pulp tissue after exposure, and application of a biomaterial directly onto the exposed pulp tissue.

Recent three randomized clinical trials (RCT) comparing success rate of partial pulpotomy with full pulpotomy have concluded an average success rate of 82% success rate for partial pulpotomy  . Systematic review and meta-analysis have reported 75% success rate of PP for cases with irreversible pulpitis(IP) . If unresponsive cases are considered as a failure, the overall success of partial pulpotomy after 1 year drops to 66%.Furthermore, in one of these RCTs more cases of PP as compared to CP had to be abandoned from the study due to uncontrolled bleeding ,this could be  attributed  to the fact that affected pulp may not have been completely eliminated in all cases as partial pulpotomy involves the removal of only superficial coronal tissue. Removal of inflamed tissue to the level of healthy uninflamed pulp is generally considered critical for healing, Perhaps insufficient removal of inflamed pulp tissue is to be blamed for the lower success rate of the partial pulpotomy technique. Additionally, partial pulpotomy may present technical difficulties when the pulp chamber space is extremely limited. Furthermore, arbitrary removal of 2-3 mm of pulp tissue is unclear to the clinician.

Due to this uncertainty in clinical approach and uncontrolled bleeding during  partial pulpotomy when performed, an alternate pulpotomy technique is proposed where ,underneath the cariously exposed pulp horn, removal of the coronal pulp tissue vertically down to the level of the affected canal orifice, and application of a biomaterial directly onto the radicular pulp tissue.(midi-pulpotomy).

In cases with IP, for removing inflammatory pulp tissue and managing haemorrhage, the midi-pulpotomy approach may have a better predictable outcome as extending the removal of the pulp tissue till the affected canal orifice may provide a cleaner incision and possibly minimal radicular pulp irritation. Technically it may provide the clinicians specific landmark or end point up to where the pulp tissue is amputated ruling out the arbitrary removal of pulp tissue thus giving specific direction.

Till date to the best of our knowledge there is no study cited in the literature which has attempted and evaluated the clinical and radiographic outcome of midi-pulpotomy technique in carious permanent mature mandibular molar teeth with symptoms indicative of irreversible pulpitis.

Thus, the aim of the present study is to evaluate and compare the outcome of an alternate pulpotomy technique (midi-pulpotomy) with Full Pulpotomy performed in carious mature permanent mandibular teeth with symptomatic irreversible pulpitis. The results of this study would provide a detailed and meticulous understanding of technical aspect of midi-pulpotomy procedure.