Comparing Different Single and Combination Chelating Agents on Sealer Penetration and Dentin Erosion.
Condition: Root Canal Infection; Periapical Abscess; Irreversible Pulpitis; Apical Periodontitis
MeSH terms: Periapical Abscess; Periodontitis; Pulpitis; Periapical Periodontitis
Study type: Interventional

Summary: 
      The basic aim of root canal treatment is to reduce the microbial content and prevent further
      recontamination in the canal. Every tooth has a variable, complex canal anatomy consisting of
      ramifications, accessory and lateral canals. Instrumentation alone cannot reach all the areas
      for cleaning.The objectives of this research study is to observe and compare the effect of
      irrigation with smearOFF , etidronic acid/ hypochlorite and other irrigants on sealer
      penetration and dentin erosion of root dentin by using scanning electron microscope (SEM) and
      Energy Dispersive X-Ray Analysis (EDX).

      Hundred extracted premolar teeth is subjected to root canal instrumentation. The endodontic
      procedure is done with protaper gold files. Initial irrigation is done by 5% sodium
      hypochlorite. Samples are divided into five groups. Each group consists of twenty single
      rooted premolars based on final irrigation regimen. There will be four experimental groups
      which are as follows (1) 17% EDTA (2) SmearOFF 3) Maleic acid (4) HEBP/NaOCL. Whereas, saline
      will be the control group. After the preparation and final irrigation of all teeth with
      experimental irrigants, sterile saline is used to flush all canals and dried using paper
      points. After final irrigation teeth are further divided into two groups (A) Sealer
      penetration (B) Dentin erosion. In both the groups standardization of root length, cleaning
      and shaping procedure are the same. For sealer penetration, obturation is done by warm
      vertical using AH plus sealer. Samples are incubated at 37º Celsius (°C) and 100% humidity
      for 7 days. The samples are marked and divided into three horizontal section at 2mm, 5mm and
      8mm. Using SEM, measure the maximum depth of sealer penetration on each side that is buccal,
      lingual, mesial and distal and take the mean for each section of sample. For dentin erosion
      (B) samples are divided sagitally & buccolingually into two halves. The half containing the
      most visible part of apical area is taken and than examined using EDX. One-Way ANOVA-test
      will be used to compare mean values of multiple groups. Tukey's post hoc test will be used to
      determine the group with significance at P≤0.05. Two observers will evaluate the results
      using kappa statistics.
    

Detailed description: 
      Data Collection Extracted permanent premolars were collected from the department of Oral and
      maxillofacial surgery at Dow Dental College ( DDC,DUHS ) and Dr. Ishrat-ul-Ebad Khan
      Institute of Oral Health Sciences (DIKIOHS, DUHS). Following extraction, teeth were cleaned
      with tap water for all visible debris and stored in 0.1 % thymol at 4 C until further use.

      METHODOLOGY

      Extracted permanent premolars were collected from the department of Oral and maxillofacial
      surgery at Dow Dental College ( DDC,DUHS ) and Dr. Ishrat-ul-Ebad Khan Institute of Oral
      Health Sciences (DIKIOHS, DUHS). Teeth were cleaned with the help of ultrasonic scaler for
      any visible debris,soft tissue remnants and calculus and later examined under dental
      operating microscope for any visible crack or fracture. Teeth with presenting fracture, craze
      lines, developmental defects were discarded in accordance to the exclusion criteria. Digital
      periapical radiographs (PA) at three different angulations (45, 90 and 120) were taken to
      confirm the presence of a single straight canal within the root. After fulfilling the above
      mentioned criteria, hundred teeth were selected and stored in 0.1% thymol at 4C until further
      use.

      Preparation of solutions:

        1. Thymol = 1grams of thymol crystals were taken and dissolve it in 50ml ethanol. After
           dissolution, this solution was made upto 1 litre by distilled water.

        2. 7 % Maleic acid = 7grams of maleic acid in powder form was dissolve in 100ml of
           distilled water to get 7% maleic acid.

        3. 18 % Etidronic acid / 5.25 % sodium hypochlorite = For 18%, take 75 ml of standard
           solution and add 175 ml of distilled water in a volumetric to make total 250 ml HEBP.
           Both irrigants were mixed in 1:1 ratio. So, 250 ml of etidronic acid were mixed in 250
           ml of sodium hypochlorite.

      Sample Preparation All samples were prepared by a single operator using the following
      protocol. A standardized root length of 16mm was measured with the help of a Vernier caliper.
      After standardization the teeth were decoronated with diamond disc in slow speed hand piece .
      Access opening was performed using diamond round bur attached to high speed handpiece (D&G).
      The canal was explored using a 10 K-file (Mailefer/Dentsply) until its tip became visible at
      the apical foramen. Then, the working length was established as 1 mm shorter than the
      anatomical apical foramen. After that the apex was sealed by hot glue to simulate the in-vivo
      closed apex condition. Canal was prepared by using ProTaper gold (Dentsply-Sirona
      Switzerland). Standard sequence of files were used. Shaping files SX , S1 , S2 and finishing
      files F1 , F2 and F3 were used. A 30 guage side vented needle was used for irrigating 5.25 %
      NaOCl after every consecutive files. After cleaning and shaping with the above mentioned
      files, all teeth were divided into five groups.

      Group Allocation The samples were randomly allocated into five groups. Four experimental and
      one control group. A computer-generated sheet (MS Excel) was used for randomization.

      Group 1: Ethylene diamine tetra acetic acid (EDTA); (n = 20) Group 2 : SmearOFF; (n = 20)
      Group 3 : Maleic acid (MA); (n = 20) Group 4 : Etidronic acid / Hypochlorite (HEBP/ NaOCl);
      (n = 20) Group 5: Saline; (n=20)

      In each group final irrigation protocol would be as follows

        1. Group 1: EDTA = 5.25% NaOCl was used during instrumentation and 5ml of EDTA used for
           1min as a final rinse.

        2. Group 2: smearOFF = 5.25% NaOCl was during instrumentation and 5ml of smearOFF as a
           final rinse.

        3. Group 3: Maleic acid = 5.25% NaOCl was during instrumentation and 5ml MA for 1 min as a
           final rinse was used

        4. Group 4: Etidronic acid/ hypochlorite =1:1 mixture of 18 % HEBP / 5.25 % NaOCL was used
           during instrumentation and the same mixture as a final rinse for 1min

      4. Group 5: Saline = 0.9 % solution was used during instrumentation and as a final rinse for
      1min

      The above mentioned experimental groups (Group 1: EDTA, Group 2: SmearOFF, Group 3: MA, Group
      4: HEBP/NaOCl were rinsed with saline to create an isotonic environment. After final
      irrigation all the canals were dried with absorbent paper points. From here, all samples were
      divided into two groups: sealer penetration and dentin erosion.

      Sample preparation for sealer penetration:

      From each experimental and control group teeth were randomly selected and obturated using
      warm vertical condensation technique. After the canals had been dried obturation was
      performed using warm vertical condensation technique using AH plus sealer. The pre-fitted
      cone was lightly coated with AH plus sealer and placed into the canal; then, a heated plugger
      was activated and placed to a point 4-5 mm short of the working length and removed the
      coronal portion of master cone. Next, down-pack was performed. The remaining root canal was
      backfilled by using an injectable gutta-percha system (EQ-V) and vertical compaction was
      performed. Coronal part was sealed with Glass ionomer cement. Samples were kept at 37 °C and
      100 % humidity for 7 days in an incubator to allow complete setting of the sealer. After 7
      days the samples were taken out from incubator. The teeth were then embedded in epoxy resin
      moulds to form resin blocks of uniform dimensions.

      Slides preparation After the resin was completely set, the samples were transversely
      sectioned at 2mm ( apical third ), 5 mm( middle third) and 8 mm (coronal third ) from the
      apex with the help of 0.3 mm blade used in diamond cutting saw ( Leco VC-50). Three sections
      with the thickness of 1mm each were obtained. Finishing was done by the help of silicone
      carbide sand paper and polishing was done using polishing machine. To remove the (in) organic
      debris, the specimens were cleaned in a bath with 15% EDTA for 2 minutes and then 3% NaOCl
      for 2 minutes. Samples were placed in sunlight for 24 hours inorder to have moisture free
      samples.

      Analysis of sealer penetration into dentinal tubules

      Sectioned teeth were marked at 2mm, 5mm and 8mm. Then specimens were mounted on metallic
      stubs and titanium-sputtered in Auto Fine Coater: JEC-3000FC. Coating was done on 20mA
      current for 30 seconds. Under scanning electron microscope (SEM JAPAN) model no JSM-IT 100
      software:In touch scope, photomicrographs were taken. A blind independent observer examined
      samples for dentinal tubule penetration of sealers at three levels - 2,5 and 8 mm from the
      root apex. Of each sample one photomicrograph most representative of the section was taken
      from root-sealer interface at a magnification of 550x. On each of these photomicrographs, the
      minimum and maximum depth of sealer penetration in the tubules was measured.

      Sample preparation for Dentin erosion

      From each experimental groups 50 teeth were randomly selected. After performing cleaning and
      shaping, all the canals were dried with absorbent paper points. Two longitudinal grooves were
      prepared on the buccal and lingual surfaces of each root using a diamond disc without
      penetrating the canals. The roots were split into two halves using chisel and mallet. The
      half containing the most visible part of the canal was taken for evaluation. Then, the
      samples were marked at 2mm (apical third), 5mm (middle third) and 8 mm (coronal third) from
      the apex.

      Analysis of Dentin erosion

      Coating of the samples was done with platinum coater for evaluation under SEM. Then the
      samples were examined by SEM at x2000 magnification. Photomicrographs were taken at each
      third. Scoring of photomicrographs were done according to Torabinejad criteria by two
      independent observers. After that EDX analysis was done to determine total content of calcium
      and phophorus and the alteration in Ca/ P caused by various irrigants.
    

Intervention name(s): Ethylene Diamine Tetra Acetic acid; smearOFF; Etidronic acid /sodium hypochlorite; Maleic acid
Intervention type(s): Drug; Drug; Drug; Drug
Intervention description(s): Final irrigation will be done with 5ml of EDTA for 1min which is the gold standard and compare it with experimental irrigants.; Final irrigation of root canal treatment procedure will be done with 5ml of smearOFF for 1min.; During whole procedure of cleaning and shaping combination product of HEBP/NaOCl will be used; Final irrigation of root canal treatment procedure will be done with 5ml of maleic acid for 1min.
Other intervention name(s): EDTA; SOFF; HEBP/NaOCl; MA
Intervention MeSH terms: Etidronic Acid; Sodium Hypochlorite; Eusol; Acetic Acid; Retinol acetate; Ethylene; Maleic acid
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Four group assigned with interventions and one control group.
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Prevention