Evaluation of Antimicrobial Photodynamic Therapy as an Adjunct to Periodontal Treatment in Smokers
Condition: Chronic Periodontitis
MeSH terms: Periodontitis; Chronic Periodontitis
Study type: Interventional

Summary: 
      The study proposes to assess the effect of multiple applications of antimicrobial
      Photodynamic Therapy (aPDT) as an adjunct to non-surgical periodontal treatment (nsPT) in
      smokers without use of antibiotics. Twenty smokers with a clinical diagnosis of chronic
      periodontitis will be treated in a split-mouth design study to either aPDT associated with
      scaling and root planing (SRP) or SRP only. aPDT will be performed by using a laser light
      source with 690 nm wavelength associated with a phenothiazine photosensitizer. The
      applications will occur in four episodes (at days 0, 2, 7 and 14). All patients will be
      monitored for 90 days. Plaque index, probing depth, clinical attachment level and bleeding on
      probing will be performed at baseline (pre-intervention period) and 30 and 90 days after the
      (nsPT). Subgingival plaque samples will be collected (at baseline and 30 and 90 days after
      the nsPT) and the counts of 40 subgingival species will be determined using DNA-DNA
      checkerboard hybridization. Gingival crevicular fluid samples will be collected (at Day 0,
      14, 30 and 90 after the nsPT) and the levels of Interleukin 1 beta, Interleukin 10 and Tumor
      Necrosis Factor alpha (Luminex) will be evaluated. Salivary cotinine levels will also be
      evaluated at baseline. Data obtained will be statistically analyzed.
    

Detailed description: 
      MATERIALS AND METHODS

      Consent to search - All patients will receive detailed information about experiment (goals,
      benefits, risks and discomforts) in accordance with a consent form in this research. All
      procedures will be subject to approval of the Ethics Committee (CEP) of Ribeirão Preto Dental
      School (FORP), University of São Paulo (USP).

      Sample Size Calculation - The sample size was determined to provide 80% power to recognize a
      significant difference of 1 mm (d) between groups with a 95% confidence interval (a = 0.05)
      and standard deviation (s) of 1.0 mm. Considering the changes in mean clinical attachment
      level (CAL) as the primary outcome variable and [Za (1.96) + Zb (0.84)]2 = 7.84. Size
      calculation was based on the following formula: n = {2[(s)2/(d)2]} · (Za + Zb)2. Therefore, a
      total of 16 patients were required. However, the number of patients enrolled in this study
      was 20, considering that some patients could be lost during follow-up.

      Experimental Design -The selected subjects will receive specific oral hygiene instruction and
      supragingival scaling in all teeth, seven days before the start of interventions. The study
      type will be split mouth with two pairs of contralateral uni-root teeth with proximal
      periodontal sites presenting probing depth ≥ 5 mm for the clinical, microbiological and
      immunological assessment. A random number table will be generated by a computer program, each
      of the selected pairs dental receive the following treatments: SRP or SRP + several aPDT
      episodes. The clinical, immunological and microbiological parameters will be evaluated at
      baseline (pre-intervention) and after the completion of non-surgical periodontal therapy. The
      periodontal clinical examinations (pre and post-intervention) will be performed by a single
      trained and calibrated examiner, who unknown the experimental groups of this study. Examiners
      are also blind to study the immunological and microbiological analyzes. SRP procedures and
      use of the aPDT protocol should be performed by other trained operator for these purposes.

      An impression with alginate will be performed in each patient to obtain the models of the
      dental arches and development of a guide plate on acetate with reference grooves to
      standardize the insertion and inclination of computerized periodontal probe (Florida Probe
      System, Florida Probe Corporation , Gainesville, FL, USA). The visible plaque index of each
      patient, will be assessed dichotomously (O'Leary et al., 1972) and determined by the
      percentage of tooth surfaces with plaque. In 6 sites of each tooth (mesio-buccal, buccal,
      distobuccal, mesio- lingual, lingual and disto-lingual) will be assessed clinical periodontal
      parameters: Probing Depth (mm) that will be measured from the gingival margin to the pocket
      bottom; relative Clinical Attachment Level (mm) that will be measured from the occlusal plate
      guide to the pocket bottom; Bleeding on probing, rated dichotomously (Ainamo, Bay, 1976), the
      presence of bleeding is considered positive when presented within 20s after the probe
      insertion for measuring probing depth. These clinical parameters and each patient's plaque
      index will be recorded at baseline (pre-intervention period) as well as +30 and +90 days
      after the non-surgical periodontal therapy.

      Examiner Calibration - The Kappa index will be used to evaluate the examiner calibration for
      collection of clinical periodontal parameters in order to measure the intra-examiner
      agreement. According to the World Health Organization (WHO) for diagnostic criteria,
      acceptable index Kappa agreement must be greater or equal to 0.85 (WHO, 1997). This agreement
      level will be used for calibration of the examiner in this project. Ten patients will be
      selected, at least two pairs of contralateral teeth uni-roots with probe depth ≥5 mm in the
      proximal sites. Each patient is scanned twice using computerized periodontal probe (Probe
      Corporation Florida, Gainesville, FL, USA) with a 48-hour interval between the first and
      second examination in order to obtain the intra-examiner reliability, which will be measured
      by determining the Kappa index.

      Immunologic Analysis - At baseline and on days +14, +30 and +90, after non-surgical
      periodontal therapy will be collected GCF samples from selected teeth. The supragingival
      plaque these elements will be removed and the sites will be gently dried with air jets and
      subsequently isolated using sterile cotton rolls. The GCF samples are obtained from the
      mesial and distal sites to the use of Periopaper strips (Oralflow Inc., Amityville, NY, USA).
      The strips will be carefully placed on the margin of the gingival sulcus for 30 seconds. The
      amount of absorbed gingival fluid will be determined by an electronic meter of wet mass
      Periotron (Oralflow Inc., Amityville, NY). The strips are placed in sterile eppendorf vials
      of the type which will be stored at a temperature of 80C for later quantification of
      cytokines (pg/ml) TNF-α, IL-1β and IL-10. Cytokine levels are determined using a 3-plex kit
      Millipore (Millipore Corporation, Billerica, MA, USA) 100TM and the Luminex system (Luminex,
      MiraiBio, Alameda, CA, USA).

      Salivary Cotinine analysis - Cotinine is a metabolite of nicotine which allows monitoring
      patient exposure to nicotine (McGuire et al., 1989). Cotinine levels will be identified at
      baseline by immunoenzymatic analysis (ELISA) (Salimetrics Inc., State College, PA, USA) using
      a kit for the quantitative analysis of cotinine in saliva according to the manufacturer's
      instructions.

      Microbiological Analysis - At baseline and on days +30 and +90, after performing non-surgical
      periodontal therapy, subgingival plaque samples of the selected teeth will be collected at
      the proximal periodontal pockets (mesial and distal). Counts of 40 subgingival species will
      be determined in each sample using the method checkerboard DNA-DNA hybridization (Birth et
      al., 2008). For the collection of subgingival plaque, the sites will be isolated with sterile
      cotton rollers and dry with air jets. The supragingival plaque will be removed carefully
      using a sterile curette. Subsequently, another sterile curette is used to collect subgingival
      plaque, starting from the deepest portion of the pocket to the coronal region. The samples
      will be transported in sterile Eppendorf vials and processing in Dental Molecular Diagnostics
      Laboratory of the School of Dentistry of Ribeirão Preto-USP

      Non-surgical Periodontal Therapy - At 7 day prior to the non-surgical periodontal therapy all
      patients will pefrom a complete periapical radiographic examination of the entire mouth. They
      will be grouped into an oral hygiene program (OHP) according to the specific needs. In this
      program patients will receive instructions for effective self-plaque, including information
      about Bass technique (Bass, 1954) and interproximal cleaning with dental floss and
      interdental brushes. They will also be encouraged to brush the tongue once a day and receive
      a single dentifrice to be used during the whole experimental period (Colgate Total, Anakol
      Ind. Com. Ltda - Kolynos do Brasil - Colgate Palmolive Co., São Bernardo do Campo, SP,
      Brasil). After the completion of this oral hygiene program, patients will be submitted to
      evaluation of clinical periodontal parameters previously described, and also will be
      collected subgingival plaque and GCF samples on selected sites (baseline - pre-intervention
      period). Soon after, will receiving supragingival scaling and polishing with a coronary
      rubber cups in all teeth in the oral cavity.

      Non-surgical periodontal therapy is initiated 7 days after the execution of the OHP and
      initial supragingival scaling. The treatment will be made by one skilled in Periodontology,
      at an interval of 24 hours by scaling (supragingival and subgingival) and root planing of all
      teeth with periodontal disease, using hand (Curetas Gracey, Hu-Friedy, Chicago, IL, EUA) and
      ultrasonic tools. The instrumentation will be held quadrant by quadrant, until adequate
      cleaning of the area and root planing, which will be checked with the help of an explorer.
      Individuals will receive professional cleaning biweekly up to three months after the end of
      nonsurgical periodontal therapy. In Fortnightly control and evaluation, patient cooperation
      towards the study will be monitored, verifying the state of oral hygiene.

      Statistical Analysis - Normality and homoscedasticity of the data will be checked. The inter-
      and intra-group comparisons in different time intervals will be achieved through adequate
      parametric or non-parametric tests. For all statistical analysis will use a 5% significance
      level. All calculations are performed using SPSS software (SPSS, Chicago IL, EUA).
    

Intervention name(s): Photodynamic therapy; Control Group; Diode Laser
Intervention type(s): Other; Other; Device
Intervention description(s): After Scaling and root planing, periodontal pockets will receive the antimicrobial (aPDT) photodynamic therapy. Shortly phenothiazine hydrochloride photosensitizing is applied at a concentration of 10mg/mL from the pocket bottom to the gingival margin. After 1 minute, irrigation is performed from periodontal pockets with distilled water to remove excess dye. The stained area is then irradiated with a diode laser with 660 nm of wavelength and maximum power of 60 mW/cm², through a fiber-optic probe of 0.6 mm diameter. Exposure to radiation will occur at six sites per tooth under treatment, making the total time of 1 minute per element, or the equivalent of 10 seconds per site. The aPDT applications will be repeated in the same way until the second week in the days 2, 7 and 14.; A sham procedure will be held simultaneously in pairs of contralateral teeth selected that will not receive the aPDT (control group).
Other intervention name(s): Laser therapy; Sham procedure
Allocation: Randomized
Intervention model: Single Group Assignment
Intervention model description: The study type will be split mouth with two pairs of contralateral uni-root teeth with proximal periodontal sites presenting probing depth ≥ 5 mm for the clinical, microbiological and immunological assessment. A random number table will be generated by a computer program, each of the selected pairs dental receive the following treatments: SRP or SRP + several aPDT episodes
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Photochemotherapy; Photosensitizing agents; Smokers