Tissue Augmentation Technique Using Free Gingival Graft Simultaneous With Posterior Mandibular Implant

Optical scans using intraoral scanner (Runyes® Model V5) were obtained at baseline, 3, 6 and 12 months post-operative for each patient. All the optical scans in standard tessellation language (STL) format, were imported to the digital software (Exocad). The best-fit algorithm was used to superimpose digital surface models, when comparing each area of interest (AOI) throughout out the follow up period. KTW (mm) was measured from the preoperative MGJ to the new MGJ using distance measurement tool in the software. KTW measurements were taken at mesial, mid-buccal and distal sites on the buccal side of the implant, values at the three sites were then averaged. Difference between KTW baseline and KTW follow-up was then analyzed to present the changes in KTW

Postoperative CBCT evaluation was performed to all the recruited patients after 1 year to assess bucco-lingual (BL) bone width changes at three levels; at implant platform, 2mm and 5mm below the implant platform. To perform radiographic measurements and comparisons and to ensure standardization and reproducibility of the CBCT images, superimposition of DICOM file sets of each patient were done using Fusion module software (OnDemand3D ver, 1.0.9, Cybermed), which allowed sub-voxel accuracy. On the fusion module, both initial and postoperative volumes were superimposed and loaded at the same time. To measure the bucco-lingual (BL) bone width changes, the lingual surface of the implant was used as a reference point. A reference line was constructed along the lingual surface of the implant on the cross-sectional cut of the postoperative CBCT volume. Then, both baseline and postoperative CBCT volumes we

Implant survival criteria were chosen according to Albrektsson et al. (1986). Surgical and prosthetic complications were also evaluated throughout the follow up timeline.

Total volume change (mm3) was calculated at 3 and 12 months postoperative via surface volume analysis within the AOI for each patient. The best-fit algorithm (iterative closet point algorithm) was used to superimpose digital surface models, when comparing each AOI throughout out the follow up periods. To measure the volume gain, the solid preoperative scans were subtracted from the follow-up scans using the Boolean operations software tool. This step will produce a new virtual object representing the volume gained. A three-dimensional (3D) inspection and metrology software (Geomagic Control X, 2022.1.0) was used to calculate the volume gain in mm3 using the measure volume tool.