Root Canal Treatment in Primary Molars With Necrotic Pulp Using Two Different Pulp Therapies
Condition: Dental Pulp Necrosis
MeSH terms: Dental Pulp Necrosis; Necrosis
Study type: Interventional
Phase: Phase 2

Summary: 
      This is a controlled, randomized, double-blind clinical study (researcher and research
      participant does not know which group they belong to), with the objective of evaluating
      clinical and radiographic performances of primary molar canal treatments with necrotic pulps
      using two obturator pulps. The CTZ paste (composed of chloramphenicol, tetracycline, zinc
      oxide and eugenol) and the ZOE paste (composed of zinc oxide and eugenol). The CTZ paste
      represents an alternative treatment that makes possible to treat canals of primary molars in
      a simplified way, without instrumentation of root canals. Studies with the CTZ pulp have
      demonstrated satisfactory clinical and radiographic results in addition to biocompatibility
      and good antimicrobial action. The zinc oxide and eugenol paste has been studied, presents
      good clinical and radiographic results, it is indicated by the American Academy of Paediatric
      Dentistry and requires mechanical chemical preparation of the root canals.

      Children of both sexes, frequenters of the paediatric dentistry clinic of the Federal
      University of Piaui who present lower deciduous molars with clinical history and / or
      radiographic evidences of pulp necrosis will participate in the study.

      The hypothesis of the study is that both pastes present similar clinical and radiographic
      results.
    

Detailed description: 
      The project followed the protocol of the Consort Statement and was approved by the Research
      Ethics Committee of the Federal University of Piaui ( 2,600,321) and registered in the
      Brazilian Registry of Clinical Trials. Software was used to determine the sample calculation
      that resulted in 36 teeth for each group. To minimize possible losses, the sample was
      increased by 20%, totalizing 86 teeth (43 per group). The teeth will be randomly allocated to
      two groups according to the type of pulp therapy to be used. Group 1: CTZ paste and Group 2:
      ZOE paste. Patients will be evaluated every three months until the end of the project,
      estimated at 36 months. Randomization will be performed per tooth who will receive a
      four-digit code, generated by Random Allocation Software, which will be present in all files
      of the patient, to ensure blinding of both patient and researcher. An independent individual
      will perform randomization, also through the same program. Numbered, opaque, and sealed
      sequential envelopes will be used to ensure concealment of randomization. The procedures will
      be performed by two researchers who will be calibrated by a researcher with experience in
      studies on Pulpal Therapy in primary teeth and the inter and intra-examiner concordances
      should be equal to or greater than 0.8, determined by the Kappa Index. A pilot study will be
      conducted with nine primary molars (10% of the sample) of children who will not be part of
      the study, to adapt the proposed methodology. Before the beginning of the pulp therapies the
      following protocol will be adopted: Initial radiography with infant positioners and manual
      processing. Guidelines for parents and children about the health/disease process, development
      of dental biofilm, prophylaxis with prophylactic paste, local anesthesia of inferior alveolar
      nerve block with 1% lidocaine with vasoconstrictor, absolute isolation of the operative field
      with rubber dam that will be disinfected with 2% chlorhexidine solution, tissue removal,
      removal of the ceiling of the pulp chamber with number 330 carbide drills spinning at high
      speed and under irrigation with saline solution sterile 0.9%. Afterwards, abundant washing of
      the pulp chamber with 2% chlorhexidine solution will be performed. Pulp therapy will follow
      specific protocols indicated for each group.

      In group 1 (CTZ paste), the root canal entries will be located and unobstructed with the
      exploratory probe tip number 5, washing with 2% chlorhexidine solution, drying of the pulp
      chamber with sterile cotton balls, manipulation of 250 mg of the CTZ paste (composed of 62.5
      mg of chloramphenicol, 62.5 mg of tetracycline, 125 mg of zinc oxide) with 0.1ml of eugenol
      in a sterile glass plate with flexible metal spatula at the time of use. The CTZ paste will
      be taken at the tip of a number 5 exploratory probe and dispensed at the entrances of the
      root canals where it will be accommodated with light pressure of sterile cotton balls. The
      CTZ paste will be protected with a thin layer of gutta-percha, previously heated in an
      alcohol lamp and placed in a thin layer on the CTZ pulp. The gutta-percha blade will be
      condensed with medium size amalgam presser and has the objective of physically isolating the
      CTZ paste from the restorative material.

      In group 2 (ZOE paste) mechanical preparation of the root canals with 2% chlorhexidine
      solution and first-series K files will be performed. The instrumentation limit shall be 1 mm
      short of the radiographic apex. After finishing the chemical-mechanical preparation, drying
      of the root canals with sterile absorbent paper cones and ZOE paste insertion with K files
      will be performed. The zinc oxide of the ZOE paste will be supplied in 250mg capsules and
      handled with 0.1ml eugenol in a sterile glass plate with metal spatula at the time of use.
      The protection of the ZOE paste will follow the same sequence as the CTZ folder.

      The teeth of both groups will be restored with high viscosity glass ionomer cement following
      the manufacturer 's specifications and adapted stainless steel crowns. For cementation of the
      steel crowns will be used glass ionomer cement for cementation following the manufacturer's
      specifications.

      After the pulp therapies have been completed, periapical radiographs will be performed
      obeying the same standardization of the initial radiographs. Those responsible for the
      children should contact the researchers in case of any postoperative complications. Patients
      will be evaluated clinically and radiographically every three months until the end of the
      project, estimated at 36 months.

      The clinical evaluations will be performed by two Paediatric Dentists who will not
      participate in the clinical part and will not know which group the teeth belong to and if
      there is a discrepancy in the evaluations, a third evaluator will be called. Radiographic
      evaluations will be performed by two Dental Radiologists, who will not participate in the
      clinical part of the study either.

      The data will be entered and analysed in the Statistical Package for Social Science (SPSS®
      for Windows, version 22.0, SPSS Inc., Chicago, USA). Pearson's Chi-square test with the P
      value set at 0.05 will be performed to evaluate the results.
    

Intervention name(s): Pulp Therapy CTZ Paste; Pulp Therapy ZOE Paste
Intervention type(s): Drug; Drug
Intervention description(s): CTZ paste is composed of 62.5 mg of chloramphenicol, 62.5 mg of tetracycline and 125 mg of zinc oxide and manipulated with 0.1ml of eugenol in a sterile glass plate with flexible metal spatula at the time of use.; The zinc oxide of the ZOE paste will be supplied in 250mg capsules and handled with 0.1ml eugenol in a sterile glass plate with metal spatula at the time of use.
Other intervention name(s): Endodontic Treatment; Endodontic Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The patients will be allocated into two groups and will remain in the group until the end of the experiment.
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Primary teeth; Dental Pulp Necrosis; Root Canal Obturation