The Outcome of Pulp Revascularization of Necrotic Mature Permanent Teeth With Periapical Lesion Using Platelet-rich Fibrin Versus Induced Bleeding: Randomized Clinical Trial

The regeneration procedures have been focused on immature teeth since there is a need for a treatment modality to give a chance for root maturation, apical closure, and root canal walls thickening which cannot be achieved by other procedures like apexification. Immature teeth have a greater chance of pulp tissue regeneration. The presence of an open apex will allow the stem cells from the apical papilla to migrate into root canals.

In the case of mature teeth, the presence of complex anatomy causes difficulties in disinfection. In addition, the presence of narrow apical pathway for stem cells migration makes them weak candidates for regeneration. However, the use of conventional root canal therapy has many drawbacks.

A retrospective study reported that even though conventional root canal therapy had prolonged tooth survival, pulp removal still led to tooth loss in comparison with teeth with normal pulp. Losing the pulp means reduced levels of proprioception in addition to the innate immunity that is disallowed after root canal therapy leaving remaining bacterial colonies in the root canal system. By applying regeneration techniques in mature teeth, we have the chance to avoid the previously mentioned drawbacks of root canal therapy and restore the neurovascular system with immune cells that will act as a line of defense mechanism against microbial attacks.

A few studies and case reports have investigated the effectiveness of regeneration procedures using blood clot as a scaffold in treating mature necrotic teeth. The idea that led toward the use of platelet concentrates as a scaffold was that concentrated platelets and growth factors collected in plasma solutions could promote local healing. Comparing it to blood clot, it increased cell proliferation over time due to its increased concentration of growth factors.

Given the drawbacks of conventional root canal treatment and limited studies in the literature on using other treatment modalities in treating mature necrotic teeth, hence the need for a randomized clinical trial with large sample size and long follow-ups emerge. This clinical study will evaluate clinically and radiographically the effectiveness of PRF versus induced bleeding in treating mature necrotic teeth.