A minimally invasive surgical technique was performed to access mandibular furcation defects in the test group, aiming to perform minimal flap reflection, minimal wound, and gentle handling of the soft and hard tissue in periodontal surgery. The use of a microsurgical approach provides magnification and optimal illumination of the surgical site improving visual acuity. Further advantages may be the reduction of flap reflection during surgery, consequently advantages in wound healing process and benefits in patient's perceptions of the procedure. A less invasive surgical procedure may lead to a less cell demand in the healing process, and a potentially reduced morbidity. The minimally invasive surgical procedures were performed using microscope.

A conventional surgical technique was performed to access mandibular furcation defects in the control group.

used to improve periodontal regenerative procedures.

The clinical measure HCAL was assessed and recorded by an experienced periodontist, blinded to the procedures to assess the efficacy of surgical procedures.

The radiographs were obtained with the paralleling technique employing an x-ray unit and a digital sensor . Customized radiographic holders for each patient . Digital subtraction radiographs (DSR) were performed using a specific software. All pairs of baseline and 6-month radiographs for each treated site were then subtracted.

Standardized regions of interest (ROIs) were select for each subtracted digital image: (1) placed in the bone's most coronal and central aspect of the furcation defect; and (2) placed at a distant untreated site acting as a radiographic control. The ROIs were not superimposed on any portion of the tooth surface. A software (Image Tool for Windows, Version 3.0, USA) was used to assess radiographic density changes that occurred in ROIs.