Regenerative Endodontic Treatment of Traumatised Teeth

Aims of the pilot study:

Primary:

• Study the clinical and radiographic success of Regenerative Endodontic Technique for the regeneration/revascularisation of immature permanent teeth with necrotic root canal systems following a traumatic injury.
• Study the qualitative and quantitative increase in root dimensions, following RET, by evaluating continued root development and thickening of dentinal walls.

Secondary:

Evaluate effect of treatment on colour change of the treated tooth compared with the healthy contralateral tooth.

Hypothesis:

Through the repopulation of the root canal space with vital tissue, Regenerative Endodontic Technique would promote continued root development and/or thickening of the dentinal walls, thereby improving the long-term prognosis of non vital immature traumatised teeth.

Methodology:

Design of the pilot study:

This will be a prospective interventional study.

Participants:

This study aims to recruit 25-30 patients. This estimation is based on discussion with the statistician and an estimation of the number of children who are referred to the LDI with non-vital immature anterior teeth following trauma, who might be eligible for participation in the study. Ethical approval will be sought through the Integrated Research Application System (IRAS). Patients referred to the Paediatric Dentistry Department at the Leeds Dental Institute (LDI) will be assessed by the clinicians for suitability for inclusion into this study based on the following inclusion and exclusion criteria.

Intervention:

At the RET clinic and once an informed consent is obtained, the treatment will be carried out over two visits each lasting about 45 minutes. During these visits, patients received the following treatment:

First Treatment Visit:

• Preoperative photographs will be taken by the principal investigator using a Fujifilm (Tokyo, Japan), Finepix S3 Pro camera with 105-mm Micro Nikon (Tokyo, Japan) f2.8 lens and sigma ring flash, EM-140DG.
• The tooth will be isolated using dry dam (Directa, Upplands Visby, Sweden).
• The tooth will be accessed and the pulp will be extirpated. The root canal system will then be irrigated with copious chemical disinfectant ( 0.5% sodium hypochlorite) for 15 minutes.
• The canal will then be negotiated with minimal or no filing to prevent further weakening of the existing dentinal walls.
• The canal will then be dried using paper points.
• In an ante-room, the two antibiotics, Ciprofloxacin and Metronidazole, will be mixed with sterile water.
• The mixture of the two antibiotics will then be carried into the root canal with special applicators so that the entire root canal is filled with the antibiotics.
• The root canal will then be hermetically sealed with a glass ionomer cement to prevent any coronal leakage or contamination of the root canal with oral microorganisms. The patient will then be discharged and an appointment made for two weeks later.

Second Treatment Visit:

• Local analgesia will be administered and the tooth will be isolated and re-accessed as described above.
• The antibiotic mixture will be flushed out of the root canal by irrigation with normal saline. Following this the root canal will be thoroughly dried with paper points.
• This will then be followed by insertion of a sterile 23-gauge needle with a length of 2 mm beyond the working length and past the confines of the root canal into the periapical tissues to intentionally induce bleeding into the root canal. The bleeding is then allowed to fill the root canal.
• Once the root canal is filled with blood, a cotton pledget will be placed in the pulp chamber and a clot will be allowed to form in the root canal.
• Once the clot has formed the pulp chamber in the coronal part will be thoroughly cleaned to remove any remnants of the blood, which could cause discolouration in the future.
• The access cavity will then be hermetically sealed with three layers of material to prevent coronal leakage and contamination; Portland cement, followed by glass ionomer and then composite resin.
• Patients will then be reviewed after 3, 6 and 9 months.

Review visits and outcomes The patients will be reviewed after 3, 6, 9 and , 12 months, 2 years and 3 years.

The following outcomes will be assessed:

Clinical:

The following will be assessed:

• Presence of normal physiologic tooth mobility.
• Tenderness to percussion.
• Free from pain or discomfort.
• No evidence of labial swelling signifying continued presence of infection.

Radiographic:

Standardised periapical radiographs will be taken before start of treatment, during the treatment and then again at 3 months,and after 9 months, 2 years and 3 years.

Trained independent examiners:

Two trained and independent examiners will evaluate the radiographs. All radiographs will be randomly shown to the examiners who will be independently asked to score the test parameters.

Image analysis:

Continuous root development, changes in dentinal root thickness and apical foramen width will be quantified.

Pulp Sensibility Tests:

At each recall pulp sensibility responses will be evaluated using thermal test (Ethyl Chloride) and Electric Pulp test (EPT).

Photographs:

Standardised intra-oral photographs will be taken before start of the treatment, 9-month, 2 years, and 3 years follow-up visits. Favourable post treatment crown colour in comparison to the pre operative photographs and to that of the contralateral tooth will be assessed using the MathWorks software as described in the study by Day et al. in 2011.