Air-polishing or Conventional Treatment
Condition: Periodontitis; Adult Periodontitis
MeSH terms: Periodontitis; Chronic Periodontitis
Study type: Interventional

Summary: 
      Background: To effectively disrupt microbial biofilm and remove dental calculus with minimal
      damage to the root surface and soft tissues with limited patient discomfort constitute a
      significant tenet of periodontal therapy. The aim of the present prospective 12-month study
      was to compare clinical and microbiological effects following an erythritol air-polishing vs.
      conventional mechanical debridement of furcation defects in a cohort of periodontal
      maintenance patients.

      Methods: Twenty patients with grade II mandibular molar furcation defects volunteered to
      enroll in this study. In a split-mouth design, two furcation sites in each patient were
      randomly assigned to either receive subgingival debridement using erythritol air-polishing
      (test) or conventional ultrasonic/curette debridement (control) at baseline, and at 3, 6, 9
      and 12 months. Probing depth, clinical attachment level and bleeding on probing were recorded
      at 3-month intervals. Subgingival microbiological samples obtained at baseline, 6 and 12
      months were analyzed using checkerboard DNA-DNA hybridization. Discomfort from treatment was
      scored at 12 months using a visual analogue scale.
    

Detailed description: 
      INTRODUCTION.Traditionally, periodontal debridement is accomplished using curettes, sonic or
      ultrasonic scalers, all presenting comparable outcomes.1,2 However, periodic root
      instrumentation may lead to dental hard tissue3-6 and soft tissue damage,7 and sensitivity
      due to exposure of dentinal tubules.8-10 Air-polishing using low abrasive glycine or
      trehalose powder has been shown to reach similar clinical outcomes as hand and ultrasonic
      instrumentation, but with less hard tissue loss.11-16 Moreover, air-polishing provides
      superior outcomes relative to patient comfort and time efficiency.7,11,12,14 Recently, a low
      abrasive erythritol powder with comparable physical properties to glycine air-polishing
      powder was introduced for subgingival air-polishing.17 Erythritol, a non-toxic, chemically
      neutral and completely water-soluble polyol is widely used in food industry as an artificial
      sweetener. Two studies comparing conventional mechanical debridement with erythritol
      air-polishing, reported similar results in supportive periodontal therapy (SPT) relative to
      clinical and microbiological outcomes.18,19 Such observations are also reflected in a
      systematic review concluding that air-polishing systems as a monotherapy are comparable to
      conventional therapy in patients undergoing SPT in single- and multi-rooted teeth without
      furcations.20 Moreover, inhibitory effects on pathogenic bacteria including Porphyromonas
      gingivalis have also been observed.21 To the investigator's knowledge, no prospective studies
      investigating the efficacy of a low abrasive erythritol air-polishing system in molar
      furcation defects during SPT have been reported. The objective of this 12-month prospective
      study was to compare clinical and microbiological effects following an erythritol
      air-polishing system vs. conventional mechanical debridement of furcation defects in a cohort
      of periodontal maintenance patients.

      METHOD AND MATERIALS. The study protocol and informed consent following the Helsinki
      Declaration of 1975 (version 2008) was approved by the Medical Research Ethics Committee
      (2016/793), University of Bergen, Norway. Participating subjects read and signed the informed
      consent prior to enrolling in the study.

      Prestudy calibration and training. Two operators performed the clinical aspects of this
      study. Author TS, masked to treatment assignments, performed all clinical recordings and
      sampling, author IU performed all treatments.

      Sample size. The sample size estimation was based on change in PD. A difference of 0.5 mm was
      considered clinically relevant.22 Standard deviation of the difference between repeated PD
      measurements from the intra-calibration exercise was 0.5 mm. A power analysis based on 20
      subjects and with the level of significance (α) set to 0.05, resulted in 98.9% power to
      detect a true difference of 0.5 mm.

      Treatments. Following baseline examination, mandibular jaw quadrants were randomized (coin
      toss) to either receive debridement using the erythritol powder/air-polishing system (test)
      or conventional ultrasonic/curette instrumentation (control) using a split-mouth study
      design. Sequence of treatments was randomized in a similar fashion. Treatments were delivered
      at baseline, and repeated at 3, 6, 9 and 12 months. Test sites thus received root debridement
      using the low abrasive erythritol powder (Air-flow powder plus®, EMS, Nyon, Switzerland )
      applied through a Perio-Flow hand piece connected to an airflow unit (Air-Flow Master®, EMS,
      Nyon, Switzerland). The hand piece was fitted with a nozzle for subgingival delivery
      directing the power/air jet perpendicular to the root surface at the water exit at the tip of
      the nozzle. The nozzle was inserted to the apical aspect of furcation sites with PD≥ 4 mm
      using striking movements over the furcation area for 5 sec.12 Sites adjoining the test site
      with PD≥ 4 mm were similarly treated.

      Control sites were debrided using an ultrasonic scaler (Piezon Master 400 Perio Slim Tip®;
      Electro Medical System, Nyon, Switzerland) with power set at 75% and water as coolant, and
      root planed with sharp curettes (Gracey SAS, Hu-Friedy, Chicago, IL, USA).

      Patients were returned to their regular SPT upon completion of study. Gingival crevicular
      fluid assessments. Gingival crevicular fluid (GCF) was recorded at baseline, and at 6 and 12
      months. Briefly, furcation sites were isolated with cottons rolls, cleaned for supragingival
      plaque, and air-dried. A perio paper strip was then placed 1-2 mm into the orifice of the
      site and left in place for 30 sec. Next, the perio strip was inserted into the Periotron
      8000® (Oraflow, Smithtown, NY, USA) calibrated to estimate the volume of GCF collected.

      Microbiological assessments. At baseline, and at 6 and 12 months the supragingival area above
      the furcation site was wiped clean using sterile cotton pellets. Three sterile paper points
      were then inserted into the pocket of the furcation site. The paper points were kept in place
      20 sec27 removed and immersed into pre-reduced, anaerobic transport medium (PRAS; Dental
      Transport Medium, Morgan Hill, CA, USA).

      Pain experience assessments. Visual analogue scale (VAS) scores were used to estimate patient
      discomfort experienced during test and control treatment.31 Scoring was performed at 12
      months following completion of the debridement with 0="no pain" and 100="worst pain I can
      imagine".

      Statistical analysis Data were entered into MS-Excel (Microsoft, Redmond, WA, USA ) proofed
      for errors and then imported into Stata, version 15 (StataCorp, College Station, TX, USA).

      Summary statistics (means ± SEM) for the clinical variables were calculated for the test and
      control at baseline, and at 6 and 12 months. Due to the repeated nature of data, a mixed
      effect model taking into consideration incomplete data at 12 months was applied to analyze
      the data at patient and tooth level. Time and treatment were considered fixed factors. Mixed
      models were applied for both primary and secondary outcome variables.

      For testing differences in microbial composition at test and control sites harboring
      different proportions of bacteria >105 at baseline, and at 6 and 12 months, logistic
      regression models with robust standard error were applied. VAS scores were analyzed using
      ordinary linear regression models with robust standard error. The level of significance was
      set at 0.05.
    

Intervention name(s): Gracey curette.; Ultrasonic scaler.; Erythritol air-polishing.
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): Root planed was performed with curettes (Gracey SAS, Hu-Friedy, Chicago, IL, USA).; Debridement was performed with an ultrasonic scaler (Piezon Master 400 Perio Slim Tip®; Electro Medical System, Nyon, Switzerland).; Treatment was performed with a low abrasive erythritol powder (Air-flow powder plus®, EMS, Nyon, Switzerland ) applied through a Perio-Flow hand piece connected to an airflow unit (Air-Flow Master®, EMS, Nyon, Switzerland).
Intervention MeSH terms: Erythritol
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomized, single-masked controlled trial (RCT). A split-mouth study design where each of the furcation in the lower jaw molars was randomized to the two specific treatments. Hence, each patient received both interventions randomly allocated to each side of the lower jaw.
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Furcation involvement; Periodontal maintenance