Tooth vitality and periapical healing: is Biodentine at par with MTA in regenerative endodontics?

The study is a prospective, double-blinded randomised control trial that compares the mineral trioxide aggregate (MTA) and Biodentine as the pulp space barrier material after induction of a periapical blood clot by over-instrumentation for endodontic regeneration in single-rooted mature permanent anterior tooth (closed apex) with apical periodontitis (periapical pathology of more than 3 mm) and having necrosed pulp. A total of 36 patients were included in the study and after randomisation were allocated equally to both the groups out of which 31 patients returned for follow-up over an 18-month period. The treatment protocol consisted of two separate appointments. At the first appointment, a standardised and custom-made radiographic guide was prepared for each patient to ensure uniformity and repeatability of the radiographs at subsequent follow-up visits. This was followed by access to the pulp chamber and biomechanical preparation of the single canal up to master apical file size. The irrigant used in each case was 1.5% sodium hypochlorite and also calcium hydroxide intracanal medicament was placed during this visit. The interval between the two appointments was not fixed and depended on the patient's symptoms following the first visit; however, the maximum allowable time frame was set at 3 weeks. During the second visit after irrigation with 17% ethylenediaminetetraacetic acid (EDTA) over instrumentation was done to induce bleeding that was allowed to fill the canal. The clot was stabilised by collagen plug and the pulp space sealer (either MTA or Biodentine) was placed below the cementoenamel junction following which composite restoration was done. The radiographs were taken before the treatment, after both the appointments and at 6, 9, 12 and 18 months subsequently by a single experienced examiner. Pre-operatively, a periapical index score (PAI) was given to each case and the sensibility test was performed at 6, 12, 18 months postoperatively using an electric pulp tester (EPT).

Participants were recruited from the Department of Endodontics outpatient clinic. The patients were aged between 10-35 years and had no systemic conditions. For inclusion in the study, participants were required to have mature anterior tooth (single root canal) with closed apex associated with apical periodontitis and necrotic pulp having periapical radiolucency of more than 3 mm on the radiograph. Patients suffering from periodontitis (ensured by periodontal probing) and those having developmental anomalies of the teeth were excluded from the study.

The normalcy of the data was assessed by Shapiro-Wilk test. Continuous data was analysed by Mann Whitney U test and the categorical data was analysed by Chi-square test and Fisher's exact test. With the level of significance set at 0.05.

Firstly, the author presented the overall healing of the periapical lesion from Fisher's exact test, which showed that after 18 months, out of 31 patients, 21 cases (67.7%) had completely healed and 10 cases (32.3%) showed signs of healing and no case remained unhealed. The difference between the Biodentine and MTA was non-significant as derived from the Chi-square test for comparison of postoperative lesion sizes score at 18 months postoperatively. Secondly, based on EPT, the author presented the regain of tooth sensibility from Fisher's exact test which shows that out of 31 cases, 22 (71%) showed a positive response to EPT and 9 cases (29%) showed no response. Again, the difference between Biodentine and MTA was non-significant.

Both Biodentine and MTA when used as pulp space barrier in regenerative endodontic procedures showed promising results. In both groups significant reduction in the size of periapical radiolucency was noted along with resolution of patient's symptoms. There was also significant regain in the tooth sensibility postoperatively. As there was no significant difference between the two in the treatment outcomes, both of these biomaterials can be used to treat apical periodontitis in mature permanent tooth as an alternative to conventional endodontic treatment in which the vitality of tooth is lost.