Evaluation of Root Roughness and Smear Layer Formation Using Conventional and Contemporary Dental Curettes
Condition: Dental Calculus
MeSH terms: Dental Calculus; Smear Layer; Calculi
Study type: Interventional

Summary: 
      The objective of the present study is to evaluate the surface texture of root after hand
      instrumentation with Gracey curette, After Five curette and Mini Five curette.Patients having
      chronic periodontitis and scheduled for extraction were randomized into four groups. Scaling
      and Root planing was performed by different curettes. Group 1 didn't under go any
      instrumentation. Group 2 was instrumented with Gracey curette, Group 3 with After Five
      curette and Group 4 with Mini Five curette. These hopeless teeth were then extracted
      atraumatically and the specimens were processed and analyzed under a Scanning Electron
      Microscope. "Roughness and Loss of Tooth substance index" and "Smear layer index" was
      evaluated using the Scanning Electron Microscope photographs.Means and frequencies were
      reported using SPSS Version-21.Cross Tabulation was made between the test groups (Control,
      Gracey Curette, After five and Mini Five) versus "Roughness and Loss of Tooth substance
      Index" and "Smear Layer Index". Chi square test was applied to see the grade distribution
      among groups. Frequencies were reported in percentages and means. P. value of 0.05 or less
      was considered as significant.
    

Detailed description: 
      INTRODUCTION:

      The main objective of scaling and root planing is to smoothen the root surface.Scaling and
      root planing can be done with a variety of instruments, however, hand instruments are still
      considered the "gold standard" for treatment. Hand and ultrasonic instruments are primarily
      used for debridement and produces root surface irregularities which enhances colonization of
      bacteria, deposition of plaque and retain more calculus.It is also a known fact that these
      debridement procedures produce a smear layer on the root surface which is detrimental to the
      healing and regeneration of periodontal tissues, as it interferes with the reattachment of
      cells derived from the periodontal ligament to the root surface.16

      Objective:

      The objective of the present study is to evaluate the surface texture of root after hand
      instrumentation with Gracey curette, After Five curette and Mini Five curette.

      Study Design:

      A Single Blinded Randomized Control Trial

      Study Setting:

      The study was conducted in the Periodontology Department of Dr. Ishrat-ul-Ebad Khan Institute
      of Oral Health Sciences Sample Size Using PASS software version 11, two independent sample
      t-test, 95% confidence interval, 80% power of test, roughness mean and standard deviation in
      group 1,hand instrument (1.2 ± 0.3um)54 and group 2,control (1.1 ± 0.56um)54 calculated
      sample size was 99 which was raised upto 120 teeth.

      Sampling Technique:

      Consecutive sampling

      Clinical Procedure:

      120 patients with ages between 35 - 60 years, having severe chronic periodontitis and
      scheduled for extraction were selected for this study. Detailed history was taken and a
      consent form was signed by the patient. Lingual surface of each tooth were subjected to
      debridement with any one of the test curettes. Patients were randomly assigned to any one of
      the four groups. Randomization was done by computer generated randomizing method.
      Randomization chart is given at the back.

      Subgingival Instrumentation was performed in vivo by a single operator by either 5/6 Gracey
      Rigid Curette, 5/6 After Five Rigid Gracey curette or 5/6 Mini Five Rigid Gracey Curette. One
      group was not instrumented and kept as control. Local Anesthesia was given and scaling and
      root planing was performed until a smooth hard surface was detected by Explorer number 17.
      Following instrumentation, a small diamond round bur on a high speed hand piece was used to
      mark the level of the free gingival margin, lingually. This groove provided a landmark for
      evaluation under scanning electron microscope.

      Instrumentation was carried out in vivo by a single operator trained in Periodontology, by a
      standard protocol. Modified pen grasp technique was used for holding the curettes. The angle
      between the cutting edge of the curette and the teeth was around 80 degree along with a good
      finger rest hence permitting a proper wrist-forearm motion. The shank of the instrument was
      kept parallel to the long axis of tooth. Degree of sharpness was maintained by sharpening the
      curettes after every 5 strokes with Arkansas stone.( Hu-Friedy Co, Chicago, IL, US) .The
      tooth were then extracted atraumatically as possible, with the beak of extraction forceps
      above the gingival margin. After extraction the teeth were rinsed in running tap water for 60
      seconds to remove all the debris and blood and placed in 0.9% NaCl solution for hydration
      until treatment.After instrumentation the samples were fixed in 2.5 % gluteraldehyde solution
      in phosphate buffer (pH 7.3) for 24 hours and then washed with phosphate buffer 3 times. All
      specimens were kept for 10 minutes in graded series of ethanol (50%, 70%, 85%, 96% ethanol)
      for dehydration.139 They were dried overnight and then mounted on a 30 mm diameter aluminum
      stub with an adhesive tape. The specimens were sputter coated with a 300 Armstrong gold
      coating in the Auto coater .The scanning electron micrographs were taken from SEM .Each
      specimen was scored blindly by two investigators specialized in Oral Biology. Six SEM
      photographs with different standardized magnifications were taken for each specimen which
      were later assessed using the indices, "Roughness and Loss of Tooth Substance Index" and
      "Smear Layer Index".17, 57 "Roughness and Loss of Tooth substance index" was analyzed taking
      the magnifications (×100, ×200, and × 500) into consideration. "Smear layer index" was
      analyzed using the magnifications (×1000, × 2000, and × 5000) into consideration. For
      computation of Root Roughness and Smear layer Index a single value was represented by taking
      mode of the three readings taken on three different magnifications of both indices. The
      micrographs were assessed by two examiners blinded to the treatment groups. Inter-examiner
      reliability was checked to ensure the calibration of the examiners by applying Intra-class
      Correlation Coefficient (ICC) test.

      Data was analyzed using SPSS Version 21.Descriptive statistics was computed regarding
      patients age, gender, brushing and flossing habits. Similarly descriptive statistics
      regarding teeth were made using frequencies and percentages. Graphs were made like pie chart
      using frequencies and bar charts using means. Cross Tabulation was made between the test
      groups (Control, Gracey Curette, After five and Mini Five) versus "Roughness and Loss of
      Tooth substance Index". Similarly Cross Tabulation was made between the test groups versus
      "Smear Layer Index". Chi square test was applied to see the grade distribution among groups.
      P. value of 0.05 or less was considered as significant.
    

Intervention name(s): Control group; Gracey Curette; After Five; Mini Five
Intervention type(s): Device; Device; Device; Device
Intervention description(s): No intervention was given; Lingual surface of tooth was debrided by Gracey Rigid curette; Lingual surface of tooth was debrided by After Five Rigid curette; Lingual surface of tooth was debrided by Mini Five Rigid curette
Other intervention name(s): 5/6 Gracey Rigid curette (Hu-Friedy Co, Chicago, IL, US); 5/6 After Five Rigid curette (Hu-Friedy Co, Chicago, IL, US); 5/6 Mini Five Rigid curette (Hu-Friedy Co, Chicago, IL, US)
Allocation: Randomized
Intervention model: Factorial Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment