Ultrasonographic Assessment of Palatal Wound Healing
Condition: Gingival Recession; Palate; Wound
MeSH terms: Gingival Recession; Wounds and Injuries
Study type: Observational [Patient Registry]

Summary: 
      Palatal-tissue harvesting is a routinely performed procedure in periodontal plastic surgery.
      Subepithelial connective tissue graft (sCTG) is considered the gold standard in root
      coverage. However, over the years, several materials have been attempted to accelerate wound
      healing and to decrease the post-operative patient discomfort and pain, which are considered
      the most common disadvantages of tissue harvesting from the palate. Reharvesting from the
      same region could be necessary in some complicated gingical recessions. For this reason,
      patients may face long treatment times due to recovery periods of the palate between
      surgeries.

      Platelet-rich fibrin (PRF) which has 3-dimensional fibrin matrix structure contributes to
      regeneration of surgical wounds by releasing growth factors for 10-14 days and showing
      angiogenic properties.

      In medicine and dentistry, ultrasonography (USG) method can be used to measure tissue
      thickness, vascularization, elasticity and blood flow. USG, as a non-invasive method, can
      provide objective data in evaluating the effects of surgical techniques and biomaterials used
      on soft tissue healing dynamics and tissue perfusion.

      The investigators hypothesised that leukocyte rich PRF (L-PRF) application to the palatal
      area after sCTG harvesting could increase palatal tissue thickness and vascularity throughout
      3-month follow-up period compared to the controls. Therefore, in this study, the
      investigators aimed to evaluate the effects of the L-PRF membrane on soft tissue donor site
      healing after harvesting sCTG in terms of wound healing dynamics using USG method.
    

Detailed description: 
      This study was planned as a randomized prospective controlled study. Patients with Miller
      class 1 or 2 gingival recession who needs root coverage surgery in the Department of
      Periodontology were included in the study. The subepithelial connective tissue graft was
      obtained in each patient using the single incision technique from the region between the
      mesial of canine and the mesial of first molar in the palate. Connective tissue dimensions
      were approximately 10 × 5 × 2 mm. Finally, the incision line was sutured with 5/0 synthetic,
      nonabsorbable, sterile monofilament suture in the control group while L-PRF membrane was
      placed to the donor site in the test group before the suturing. Patients were evaluated using
      an ultrasonography device (MyLab™ Seven, Esaote, Genoa, Italy) at the Department of Oral and
      Maxillofacial Radiology. USG measurements were performed on days 0, 3, 7, 14, 21, 30 and 90
      for palatal tissue thickness and tissue vascularization by an oral and maxillofacial
      radiologist with at least six years of experience. A 6-18 MHz intraoral probe was used in
      intraoral USG examinations. Sterile gel was applied to the intraoral probe and covered with a
      stretch film. Then, it was placed directly on the mucosal surface of the donor site in the
      palatal area. Mucosal thickness was evaluated using the B-mode of the device, and
      vascularization was evaluated using the color doppler and pulsed wave doppler modes of the
      device. The mean pulsatility index (PI) values of each patient were calculated and considered
      for statistical analysis.

      The power analyse of the study was performed for sample size calculation. Sample size was
      calculated using a statistical program (G*Power; Universitat, Dusseldorf, Germany) for α =
      0.05 and effect size = 0.26. The analyses revealed that 10 subjects per group achieved a
      power of 80 % with 95% confidence.

      The data were analysed with the SPSS 21 program (SPSS Inc., Chicago, IL). Continuous
      variables were presented as mean ± standard deviation and categorical variables as numbers
      and percentages. Shapiro-Wilk test was used to detect data's normality. For the comparison of
      the parameters of the study groups, independent samples T-test test was used for normally
      distributed data while Mann Whitney U test test was performed as non-parametric test.
      Within-group comparisons between the different time periods were tested with repeated
      measures of ANOVA. Bonferroni correction was performed for multiple variations. The
      statistical significance value was accepted as p < 0.05.
    

Intervention name(s): connective tissue harvesting; ultrasonography; autolog platelet rich fibrin application
Intervention type(s): Procedure; Diagnostic Test; Other
Intervention description(s): The subepithelial connective tissue graft was obtained in each patient using the single incision technique from the region between the mesial of canine and the mesial of first molar in the palate. Connective tissue dimensions were approximately 10 × 5 × 2 mm. Finally, the incision line was sutured with 5/0 synthetic, nonabsorbable, sterile monofilament suture; A 6-18 MHz intraoral probe was used in intraoral USG examinations. Sterile gel was applied to the intraoral probe and covered with a stretch film. Then, it was placed directly on the mucosal surface of the donor site in the palatal area. Mucosal thickness was evaluated using the B-mode of the device, and vascularization was evaluated using the color doppler and pulsed wave doppler modes of the device. The following equation is used and calculated by US unit: Pulsality index (PI) = (Vmax-Vmin)/(Vmean) (Vmax is peak systolic flow velocity, Vmin is diastolic flow velocity and Vmean is mean flow velocity). The mean PI values of each patient were measured.; Leukocyte rich PRF (L-PRF) was obtained with the centrifugation of the two tubes at 2800 rpm for 12 minutes. After centrifugation, L-PRF clots were taken from the tubes using sterile tweezers, separated from the red blood cell base using scissors. Then L-PRF membrane was placed into the donor site.
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients with Miller 1 and 2 gingival recession who need root coverage treatment
      
Keywords: platelet-rich fibrin; wound healing; ultrasonography; blood-flow velocity