Conventional Coronectomy vs Coronectomy in Combination Vital Pulp Treatment Using Calcium Silicate
Condition: Impacted Third Molar Tooth
MeSH terms: Tooth, Impacted
Study type: Interventional

Summary: 
      The aim of this study was to compare the conventional coronectomy and the combined
      coronectomy technique with vital pulp treatment. The primary outcome of the study was to
      evaluate the success rates of two treatment techniques based on clinical and radiologic
      observations regarding inferior alveolar nerve injury, root exposure and formation of
      periapical lesion. The secondary outcome was to evaluate the change in periodontal condition
      of the second molar adjacent to the operation area, dentin bridge formation and root
      migration.

      Between March 2018 and February 2022 eligible patients attended University Hospital for the
      removal of lower third molar with risk of inferior alveolar nerve (IAN) damage invited to the
      study. 60 teeth meeting the inclusion criteria in 52 participants were randomized to Test
      (with BiodentineTM, n=30) and Control (without BiodentineTM, n=30) groups. Neurological
      injury and post-operative pain were clinically evaluated at 12th months and 1st week,
      respectively. Root migration, dentin bridge formation and periapical lesion development were
      evaluated using Cone Beam Computed Tomography (CBCT) at 12th month. The change in the
      periodontal status of second molar was evaluated by measurement of pocket depth at 1st, 3rd
      and 12th months and the distance between base of the bone defect and the marginal crest and
      cemento-enamel junction and at 6th and 12th months month.
    

Detailed description: 
      The surgical removal of mandibular third molar teeth is one of the most frequently performed
      oral surgical procedures. One of the complications might occur during surgical removal of
      these teeth is injury to inferior alveolar nerve (IAN) which may lead to altered or loss of
      sensation to lower lip, chin, teeth and gingiva on the operated side. The risk for IAN injury
      may not be avoidable, even though the surgery was performed by an experienced surgeon and the
      positional relationship between the mandibular third molar and IAN was assessed accurately
      prior to surgery.

      Pericoronitis, dental caries and periodontal disease are the most common pathologies
      associated with mandibular third molar teeth. Theoretically, removal of crown part of the
      teeth with a vital pulp and leaving the roots behind might be adequate to relive clinical
      symptoms arise from these pathologies. This technique was first described by Ecuyer and
      Debien in 1984 as coronectomy to prevent injury in case of close relationship of mandibular
      third molar with inferior IAN.

      As shown previously in randomized clinical trials, fewer complications in terms of
      post-operative pain, IAN deficiency and dry socket were observed after coronectomy.
      Systematic reviews have confirmed that incidence of IAN injury was lower with coronectomy
      when compared to total removal in case of the lower third molar radiographically closely
      related with the IAN. Nerve injury was reported to occur in up to 20% of cases temporarily
      and 1-4% of cases permanently after total extraction, whereas 0-5.5% of cases temporarily
      after coronectomy.

      Radiographic assessment using panaromic radiographs is the first step for coronectomy
      procedure. Presence of the interruption of the white line of the mandibular canal wall,
      darkening around the root(s), diverging of the mandibular canal, narrowing of the mandibular
      canal, narrowing of the root(s) and deflection of the root(s) are the indicators of increased
      risk for IAN injury. In recent years, cone beam computer tomography (CBCT) scanning is widely
      used method for further investigation to demonstrate the three-dimensional relationship
      between the tooth and IAN. Additionally, eligibility of the third molar for coronectomy
      should also be evaluated to be free of caries, pulpal inflammation and abnormal surrounding
      tissue. Coronectomy is contraindicated for non-compromised patients with good healing
      potential due to medical conditions such as diabetics, long-term steroid use, chemotherapy or
      radiotherapy.

      One of the possible complications after coronectomy is migration and eruption of the roots
      left in the bone. Bone formation over the retained roots is expected to avoid eruption of
      these roots in the oral cavity. In case of eruption, remaining roots should be extracted.
      Another possible complication is periapical lesion development due to necrosis of the pulp.
      With conventional coronectomy procedure, no pulp treatment of the remaining roots is
      performed. Previous in vivo studies demonstrated that pulp retained vital after coronectomy.
      However, presence of pain and infection after coronectomy was reported in randomized clinical
      trials. Vital pulp treatment of the remaining roots with a bioactive material may have the
      potential to enhance both dentin and bone formation leading to reduced complications related
      with periapical inflammation and tooth migration.

      In the literature, there is no study concerned with the clinical success of coronecyomy in
      combination with vital pulp treatment, except a case report. Therefore, the aim of this
      randomized clinical trial was to compare clinical success of conventional coronectomy and
      coronectomy in combination with vital pulp treatment based on clinical and radiologic
      evalutions. The null hypothesis tested in this study was that application of calcium silicate
      (Biodentine, Septodont, St Maur-des-Fosses, France) after coronectomy had no benefits to
      reduce above mentioned post-operative complications.
    

Intervention name(s): Coronectomy; Pulp Capping with calcium silicate
Intervention type(s): Procedure; Procedure
Intervention description(s): Removal of crown part of the mandibular third molar; Application of a pulp capping material (BiodentineTM, Septodont, St Maur-des-Fosses, France) on pulp tissue to preserve the vitality of the residual pulp and prevent inflammation
Intervention MeSH terms: Calcium
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: coronectomy; vital pulp therapy; impacted third mandibular molar