Effect of Glass Ionomer Cement as an Interim Restoration in Diagnosis of Pulpal Status
Condition: Pulpitis
MeSH terms: Pulpitis
Study type: Interventional

Summary: 
      Aim: To evaluate whether glass ionomer interim therapeutic restoration (ITR) in asymptomatic
      teeth with deep cavities can help in determining the pulp status. Methodology: 146 mandibular
      molars with deep carious lesion having positive response to pulp sensitivity were randomly
      allocated to two study groups (75-ITR, 71- NON-ITR group). In the first group after partial
      caries removal(PCR), interim therapeutic restoration of glass ionomer cement (GIC) Ketac
      molar was placed for one month before definitive adhesive restoration. In NON-ITR group,
      cavity preparation was similar to ITR group, but definitive restoration was done in the same
      visit. Two examiners evaluated the clinical and radiographic outcomes for 18 months. Success
      was defined as absence of signs and symptoms of irreversible pulpitis and absence of
      periapical alterations.
    

Detailed description: 
      Introduction Preservation of pulp vitality while managing the deep carious lesions is often a
      great challenge and requires procedures like pulp capping and pulpotomy collectively termed
      as vital pulp therapy (VPT). Such treatment involves elimination of bacteria from pulp
      dentine complex and establishing an environment that will prevent any future bacterial
      contamination and improves survival prognosis. Management of deep carious lesions in recent
      years has changed from complete caries removal to partial caries removal. Partial caries
      removal has gained importance due to reduction in pulpal exposures, less postoperative
      complications, more preservation and maintenance of pulp tissue .

      The important concern during VPT is accurate assessment of pulpal status. Methods to
      determine pulpal vitality include patient history, signs and symptoms, radiographs and pulp
      sensibility tests. One of the hallmarks of pulpal diagnosis is that it is difficult and has a
      high rate of inaccuracy. Pain on cold and hot stimuli cannot be considered as a reliable
      reference for making a treatment decision. Also insufficient evidence was found to determine
      the diagnostic accuracy of symptoms, signs, and diagnostic tests to assess the pulp status.

      Studies using visual and histological inspection of exposed pulp to examine status of pulp
      reported marked variation in sensitivity of cold and electric pulp test from 0 .21 to 0.94,
      with relatively less variation in specificity from 0.73 to 0 .96.Sensitivity decreased to 67%
      when the spectrum of the disease was altered i.e. when asymptomatic teeth with deep carious
      lesions were included . Diagnosis of pulp status is often easy when there is a clear
      distinction between healthy and necrosed pulp however it is more difficult in asymptomatic
      teeth with deep carious lesions.

      Recently, Coll et al. proposed that glass ionomer cement (GIC) as interim therapeutic
      restoration (ITR) improved pulpal diagnosis and VPT outcomes while interpreting diagnostic
      assessment based on clinical pulp therapy success. Vij et al. reported that GIC temporization
      for 1-3 months increased success of the subsequent VPT from 79% to 92% .However; both of the
      studies were retrospective and were in deciduous teeth.

      No prospective clinical study has so far been conducted in permanent teeth that demonstrate
      the effectiveness of GIC and other adhesive restoration materials in determining the pulpal
      status. Aim of this double blinded randomized controlled trial was to assess the
      effectiveness of GIC interim restoration in determining the pulpal status of asymptomatic
      teeth with deep carious lesions. Null hypothesis was that GIC as ITR does not improve the
      clinician's diagnostic ability to determine the correct pulp clinical diagnosis and does not
      improve the treatment outcomes in vital pulp therapy.

      Material and Methods:

      Case Selection This prospective randomized clinical trial was conducted at the Department of
      Conservative Dentistry and Endodontics, Post Graduate Institute of Dental Sciences, Rohtak,
      India. The study protocol was approved by the Ethical Committee (PGIDS/IEC/2015/64) of the
      Post Graduate Institute of Dental Sciences. A total of 146 patients were included with an age
      range of 15-54 years. The inclusion criteria for the study were: 1) mature permanent
      mandibular molars having deep carious lesions involving half or more of the dentine detected
      by radiographic examination, 2) pulp sensibility confirmed using the electric pulp test
      (Digitest D626D; Parkell Electronics, New York, NY) and the cold test (Endo frost, Coltene,
      Whaledent), 3) absence of apical and furcal radiolucency determined by radiographic
      examination, 4) absence of clinical symptoms of irreversible symptoms, fistula, swelling and
      abnormal tooth mobility. Clinical diagnosis of vital pulp was made by the chief supervisor
      (Sanjay Tewari) on the basis of radiographic and clinical examination and the pulp
      sensibility tests. Patients were excluded if they presented with signs and symptoms of
      irreversible pulpitis, had negative response to vitality tests before or after ITR, diabetic,
      immunocompromised, pregnant, or had a positive history of antibiotic use in past one month or
      required antibiotic prophylaxis. Informed consent explaining benefits and risks of treatment
      was taken from patients before participation in the trial.

      Sample Size Calculation and Randomization The sample size calculation was done on the basis
      of difference in the percentage of success of vital pulp therapy using GIC (98%) versus
      non-GIC group (75%) (12) α=5% with a power of 90%. This indicated the need for 48
      restorations per treatment group. Given an expected attrition rate of 20%, 60 teeth were
      included in each treatment group. Randomization was developed to eliminate any bias on the
      part of the investigators and to equalize the number of patients between the 2 treatment
      groups. Using an equal proportion randomization allocation ratio, one of the investigators
      (M.J) created envelopes containing concealed assignment codes that were assigned sequentially
      to eligible patients.

      Clinical Procedure The procedure was performed under local anesthesia and rubber dam
      isolation. Carious tissue from the lateral walls and dentinoenamel junction was removed
      completely by using low-speed metal burs and/or hand excavator. Superficial necrotic dentin
      was removed from the pulpal and axial wall using low speed round bur. A layer of soft, wet
      carious dentin was left adjacent to pulpal wall. The cavity was cleaned with distilled water
      and dried with sterile filter paper. In group ITR, the cavity was filled with GIC ( Ketac
      Molar (3M ESPE, St. Paul, Minn., USA).Cavity was reopened after 1 months in asymptomatic
      patients , restoration was removed completely ,base of resin modified glass ionomer
      cement(RMGIC) (Fuji Lining LC;GC,Tokyo,Japan)was applied and cavity was restored with resin
      composite(Tetric N-Ceram;Ivoclar Vivadent) according to manufacturer instructions.

      In NON-ITR group, cavity preparation was done similar to ITR group, after partial caries
      excavation ,base of RMGIC (Fuji Lining LC;GC,Tokyo,Japan) was applied and all cavities were
      restored with resin composite(Tetric N-Ceram;Ivoclar Vivadent) according to manufacturer
      instructions.

      Outcome Assessment Two blinded examiners assessed the clinical and radiographic outcomes of
      test and control treatments at 1, 3, 6, 12, 18 months after treatment. Success was defined as
      absence of signs and symptoms of irreversible pulpitis (spontaneous pain, fistula and
      swelling), positive response to pulp sensibility tests and absence of periapical alterations
      (radiolucency at furcal or periapical region, calcification) (combined outcome). Pretreatment
      pulpal diagnosis was considered successful when teeth treated with or without ITR were
      diagnosed as vital and none of clinical and radiographic signs and symptoms of failure
      developed during 18 month follow up.
    

Intervention name(s): Restoration
Intervention type(s): Procedure
Other intervention name(s): Filling
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Diagnostic