The aim of the present study was to evaluate the impact of surgical flap design on the healing of intrabony defects treated by means periodontal regeneration. Forty patients were enrolled and allocated random in two groups. Patients of test group received a minimally invasive surgical flap , while patients of control group received a conventional access flap. In both group the intrabony were treated by means the same periodontal regeneration procedure (i.e application of enamel matrix derivative). Periodontal parameters were recoded at baseline and after 12-months observation time.

This study was designed as multicenter randomized control clinical trial. The present trial was conduced according to CONSORT statement for improving the quality of reports of parallel-group randomized trials .

The intra-bony defects of subjects allocated in test group were treated with a combination of minimally invasive surgical technique (MIST) and enamel matrix derivative(EMD), while the intra-bony defects of control group were treated using a combination of conventional open flap debridement with papilla preservation (COFD+PP) and EMD.

Primary outcome

The primary outcome was based on Clinical attachment level gain( CAL gain)

Null hypothesis

Statistically significant different in terms of CAL gain will be recorded between test and control procedures.

Sample Size Calculation

The investigators are planning a study of a continuous response variable from independent control and experimental subjects with 1 control per experimental subject. In a previous study the response within each subject group was normally distributed with standard deviation 0,92. If the true difference in the experimental and control means is 0,97, we will need to study 20 experimental subjects and 20 control subjects to be able to reject the null hypothesis that the population means of the experimental and control groups are equal with probability (power) 0,8. The Type I error probability associated with this test of this null hypothesis is 0,05. Twenty-six patients were enrolled in the study and allocated in test or control group. In each patients 1 intra-bony defect was considered.

Randomization

The patients were randomly assigned to one of the two experimental procedures. The allocation was carried out using a commercially available computer software package. Treatment allocation was performed at time of surgery by opening an envelope containing the information test (i.e.EMD + MIST) or control (i.e.EMD + COFD+PP) procedure, respectively.

Inclusion Criteria

• Patients suffering from chronic periodontitis;
• Male and female ;
• Age 18 years old;
• Presence of intra-bony defects (contained and non-contained defects) in either the maxilla or the mandible with a PD ≥ 6 mm.
• II and III wall Intra-bony defects with an intra-bony component range from 3 mm to 6 mm for both groups;
• Intra-bony defect located only at one aspect ( mesial or distal)

Exclusion Criteria

• Patients with systemic disease;
• Prolonged antibiotic treatment or anti-inflammatory treatment within 4 weeks prior to surgery;
• Pregnant or lactating;
• Tobacco smokers;
• Patients with FMPS and FMBS 25 % after completion of non surgical periodontal therapy (recorded at six sites per tooth);
• Furcations;
• Third molars
• Teeth with circumferencial defects
• I-wall intra-bony defects

Inclusion Criteria:

• • Patients suffering from chronic periodontitis;

  • Male and female ;
  • Age 18 years old;
  • Presence of intra-bony defects (contained and non-contained defects) in either the maxilla or the mandible with a PD ≥ 6 mm.
  • II and III wall Intra-bony defects with an intra-bony component range from 3 mm to 6 mm for both groups;
  • Intra-bony defect located only at one aspect ( mesial or distal)

Exclusion Criteria:

• • Patients with systemic disease;

  • Prolonged antibiotic treatment or anti-inflammatory treatment within 4 weeks prior to surgery;
  • Pregnant or lactating;
  • Tobacco smokers;
  • Patients with FMPS and FMBS 25 % after completion of non surgical periodontal therapy (recorded at six sites per tooth);
  • Furcations;
  • Third molars
  • Teeth with circumferencial defects
  • I-wall intra-bony defects