Efficacy of Azithromycin as an Adjunct to Non-Surgical Periodontal Treatment
Condition: Periodontitis
MeSH terms: Periodontitis
Study type: Interventional

Summary: 
      This study evaluates the effect of the systemic administration of azithromycin as a therapy
      associated with non-surgical periodontal treatment, in the clinical and microbiological
      variables of patients with Severe Periodontitis with moderate rate of progression (Stage III
      grade B). A double-blind, randomized, controlled trial was conducted with 18 voluntary
      patients with a history of moderate to severe chronic periodontitis, who met the inclusion
      and exclusion criteria and signed an informed consent.

      The intervention group received non-surgical periodontal therapy (NSPT) plus azithromycin,
      and the control group received NSPT plus placebo. Probing Pocket Depth (PPD) Clinical
      Attachment Level (CAL),O'Leary index (OI) and Bleeding on Probing (BoP) were evaluated as
      clinical variables while Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema
      denticola (Td), Fusobacterium nucleatum (Fn) were the microbiological variables detected by
      conventional Polymerase chain reaction (PCR).
    

Detailed description: 
      Definition of the sample: Patients over 18 years old admitted to the Diagnostic Unit of the
      Faculty of Dentistry (DUFD), Viña del Mar campus of the Universidad Nacional Andres Bello
      (UNAB) during 2016, with a diagnosis of severe periodontitis, meeting both the inclusion and
      exclusion criteria and voluntarily agree to participate of the present research work, signing
      an informed consent. The chosen participants were informed of the nature of the research,
      potential risks and compensation for participating in the study, obtaining informed consent
      from every patient.

      Sample Size Calculation: To calculate the minimum sample size necessary for the constitution
      of the control and intervention groups, the variance of the probing depth difference were
      considered as fixed values, which were based on the results described above.Considering the
      above and using a level of significance of 5%, a statistical power of 80% and an estimation
      error of 1 mm, at least 7 patients were obtained for each group, giving a total of 14 minimum
      subjects to study.

      Protocol and clinical exam: Out of a total of 32 patients who were selected, 20 of those who
      met the inclusion criteria were randomly assigned by the study coordinator to one of the two
      groups using a random generation sequence employing a software. Two subjects declined to
      participate in the research, so the study had 9 participants in each group. In this way, two
      groups were formed to investigate: an intervention group that received NSPT plus 500 mg of
      azithromycin once a day for three days immediately after the NSPT, and a control group that
      received NSPT plus placebo under the same conditions as the intervention group.

      Randomization: Only the main investigator, who made the randomization by using the Epidat 4.0
      program, had knowledge about the content of the containers and the group to which each
      patient belonged in the study, therefore, was in charge of labeling the containers, achieving
      in this way that collaborators and participants in the investigation did not know their
      content until after the study was finished.

      Standardization and calibration: The data was collected using instruments and supplies with
      the same commercial brands, in a single chair, under the same lighting and by a single
      examiner in the case of clinical data and another examiner for microbiological variables.

      For standardization, measurements were performed under the same conditions and using the same
      type of instrument, in order to reduce the associated bias. The instruments used for data
      collection were all the same in design and brand: Basic Examination Kit: Mirror, caries
      probe, tweezers (Hu-Friedy® Manufacturing Inc., Chicago, IL, USA), manual periodontal probe
      (North Carolina Probe. Hu-Friedy® Manufacturing Inc., Chicago, IL, USA), plaque finder
      tablets (Curaprox © CURADEN AG, Switzerland) and number 40 sterile paper cones (Johnson &
      Johnson, Tokyo, Japan).As there was only one examiner (KL) involved in the study,
      intra-examiner reliability assessment was executed. This examiner (intra-class correlation
      coefficient of 0.96 and 0.95 for PPD and CAL), recorded the all stipulated variables, in a
      clinical file designed especially for the study. Microbiological sampling and NSPT were
      performed by a single clinician (PO).The complete process of PCR was performed by a
      biochemist belonging to the microbiology laboratory, Santiago campus of the UNAB.

      Periodontopathogens: The presence of periodontopathogens was considered when exposing the
      agarose gel of the electrophoresis to ultraviolet light, a band at the site of the 197 base
      pairs (bp) was observed in the lane possessing the patient's subgingival bioflora sample of
      Pg, 316 base pairs for Td, 745 for Tf and 167 for Fn.

      Data collection and instrument: Prior to the data collection, all subjects belonging to the
      study were asked for a panoramic radiograph for diagnostic purposes. Subsequently, the
      periodontal examination was performed registering the clinical variables described above in a
      clinical record.

      Obtaining microbiological samples: The microbiological examination was performed before NSPT
      on both groups. The collection of microbiological samples was based on a protocol that is
      used at the University of Chile. Using sterile paper cones number 40, a sample of subgingival
      bioflora was taken from the site with the highest CAL, within those with PD ≥ 5mm, and an
      oral hygiene instruction was performed. Before the collection of subgingival bioflora, the
      area was cleaned with a sterile gauze to eliminate the supragingival biofilm. Then, with a
      tweezer, a paper cone was taken, and its tip was placed in the sulcus of the study site for
      20 seconds, to ensure the absorption of the crevicular fluid and subgingival bioflora. Each
      biological sample obtained was suspended in an Eppendorf tube with 1 ml of distilled water
      and transported in a refrigerator at a temperature of 4°C approximately, within a time not
      exceeding 3 hours, to be then temporarily stored at -80°C, until its transfer and subsequent
      extraction of deoxyribonucleic acid (DNA) and PCR technique processing. The time between
      sampling and DNA extraction did not exceed 48 hours, to avoid deterioration of the biological
      material.

      Periodontal Treatment: Once the preliminary collection of all the variables was completed,
      non-surgical periodontal treatment (NSPT) was carried out, beginning with supra and
      subgingival full-mouth decontamination, using an electric piezo (DTE®, Guilin Woodpecker
      Medical Instrument Co., Ltd., Guilin, Guangxi , People's Republic of China), followed by root
      planning at sites presenting PD ≥ 5mm and CAL≥ 4mm, using Gracey curettes (Hu-Friedy®
      Manufacturing Inc., Chicago, Illinois (IL), USA). This therapy was performed in all patients,
      both in the intervention and control group, under full mouth treatment protocol, in 1 or 2
      work sessions, lasting from 1 to 2 hours, achieving treatment within 24 hours.

      Azithromycin or placebo administration: At the end of the last treatment session, the
      antibiotic azithromycin (Azithromycin, Laboratory Chile) or a placebo (Lactose, Galenic
      Pharmacy) was administered, depending on the group, intervention or control respectively, to
      which the patient belonged. For both therapies, the administration regimen was 1 tablet of
      500 mg orally per day, for 3 consecutive days.To maintain the double-blind, the containers
      used for the azithromycin and placebo presented the same characteristics regarding size and
      color. About the azithromycin tablets and placebo, these were visually identical.

      Subsequently, at the first, third and sixth month after the end of the non-surgical
      treatment, a new collection of all the clinical variables measured at the beginning of the
      study was performed, while the microbiological variables were measured again at the third and
      sixth months after treatment, from the same site used in the first sampling.

      Statistical Analysis: The analysis of the data was carried out according to the specific
      objectives of the research, using the Statistical Package for the Social Sciences (SPSS)
      computer program. A descriptive analysis was performed in which the qualitative variables
      were studied by frequency, while the quantitative ones were analyzed through the average. The
      results obtained in both cases were expressed in frequency tables. For each variable, the
      data normality test was performed according to the Shapiro-Wilk test. Afterwards, an
      inferential analysis was carried out for the quantitative variables. The level of statistical
      significance was established according to the Student t and Chi-Square test, while for the
      qualitative variables, the non-parametric McNemar test was performed. Significant p-values
      <0.05 were considered, aiming to present a confidence level of 95%.

      Ethical implications, biosecurity and others Each patient was informed in detail all that
      entails carrying out the research work, according to the level of understanding of each
      subject and was given an informed consent, in which the objective of the study is specified
      in writing along with the procedures to be performed for both, the control group and the
      intervention group, in addition to the costs and benefits of participating. The design,
      together with the protocol of the present study, was based on the Declaration of Helsinki and
      was approved by the Scientific Ethics Committee of the Faculty of Dentistry, Viña del Mar
      campus of the UNAB.On the other hand, for the correct development of the investigation,
      pertinent clinical examinations were carried out following the biosecurity regulations in
      force at that establishment. The sample taken from the subgingival bioflora of the patient
      consists of a totally innocuous, fast and simple technique, which was obtained only from a
      periodontal site. Once the investigation was completed, all the extracted material was
      destroyed, achieving its elimination by means of the international standards of handling of
      biological samples. All participants were given free of charge the necessary elements for
      proper oral hygiene, teaching them the correct way to sanitize their mouth. In addition, they
      were made aware of the diagnosis, treatment plan and results obtained. Regarding the patients
      examined who did not meet the inclusion and / or exclusion criteria of the study, they were
      referred to the subject of Clinical Periodontics for the fourth year, as a teaching assistant
      or Postgraduate of Periodontics at the UNAB, as appropriate, in order to be treated
      periodontally. Regarding the use of systemic antibiotics as adjuvant treatment, this has been
      shown to be clinically more effective than the periodontal treatment associated with placebo.
      Azithromycin, on the other hand, has an action spectrum that involves aerobic and anaerobic
      Gram negative bacteria, among which are the periodontopathogens, it has an excellent
      gastrointestinal absorption, long half-life and limited adverse effects. Due to its
      properties, it could become a viable alternative in periodontics to the current adjuvant
      antibiotic regimen of amoxicillin with metronidazole.Regarding the use of the placebo
      (lactose), it is characterized for being of the pure or inactive type, that is, what
      corresponds to an inert substance that has no pharmacological action in the patient, which is
      why it is usually the type of placebo of choice in studies of clinical trials. Lactose is a
      disaccharide resulting from the binding of glucose and galactose, and these placebos
      correspond to capsules with a crystalline powder, white, odorless and with a slightly sweet
      flavor, whose side effects to its use occur infrequently, mainly in patients who have
      ingested excessive amounts of lactose and / or have intolerance to it, generating symptoms
      such as abdominal pain, flatulence, diarrhea, bloating, nausea and vomiting.It should be
      noted that, despite the low prevalence of adverse reactions in both, lactose and azithromycin
      , patients were warned about the possible effects, indicating that in the face of any
      discomfort attributable to the consumption of the tablets they would go to the researchers to
      stop the administration of these and be eliminated from the study.
    

Intervention name(s): Lactose tab; Azithromycin
Intervention type(s): Other; Drug
Intervention description(s): Tablet containing lactose Procedure: Periodontal treatment Scaling and root planning; Tablet containing 500mg Azithromicyn. Procedure: Periodontal treatment Scaling and root planning
Other intervention name(s): Azithromycin 500mg Tab
Intervention MeSH terms: Azithromycin
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: A double-blind, randomized controlled trial, where patients with a Severe Periodontitis with potencial for additional tooth loss and moderate rate of progression (Stage III grade B). The intervention group received non-surgical periodontal therapy (NSPT) plus azithromycin, and the control group received NSPT plus placebo. The clinical variables were measured before the treatment, and in the first, third and sixth month of the end of the NSPT, while the microbiological variables were measured before the treatment and in the third and sixth month after treatment.
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Azithromycin; Periodontal debridement; Antibiotics; Periodontitis