Antimicrobial dressings for root canal therapy

Root canal therapy involves the opening the tooth to expose the internal part and gain access to the root canal which is full of bacteria and putrefied pulp tissue. The root canal is cleaned mechanically and washed with antimicrobial solutions, dressed in the first visit. It is then filled on the second visit. Some clinicians prefer to have single visit procedures as maintaining a bacteria-free root canal in between visits is challenging.

The scope of root canal therapy is to remove the bacteria and to seal the root canal to prevent reinfection. It is very important to maintain the microbial load low in between clinical visits. This is challenging as bacteria get lodged in the intricate tooth structure. Two-visit root canal therapy is advocated as the patient symptoms may not be resolved and if the treatment is completed, a revision which is more complex will be necessary. To avoid microbial contamination in between treatment visits, non-setting calcium hydroxide paste is placed in the canal. The calcium hydroxide acts by microbial elimination through a high pH. It is injectable so cannot be always placed to the correct length and remain contained in the root canal. Removal of the calcium hydroxide can be challenging as it is washed away but traces may remain in the root canal and interfere with the root canal filling material.

Failure of root canal therapy requires further intervention which is more complex and expensive than the primary treatment. It is thus necessary to be able to reduce the microbial load in the root canal during treatment and maintain this in between clinical treatment visits. Due to this, a targeted approach is being proposed with development of antimicrobial adjuncts which will target specific microbial species till the root canal is closed off permanently. We thus propose to develop an antimicrobial adjunct to be able to manage the complex microbiology inside the root canal.