Bone Alterations On Maxillary Anterior Implants With Simultaneous GBR-a Clinical And Cone Beam Computed Tomography Study

ObjectivesThe cone beam computed tomography study (CBCT) evaluated horizontal and vertical dimensional changes,with bone density changes to the facial bone following maxillary anterior implant placement and simultaneous GBR.Methods:CBCT scans taken before (T0), immediately after (T1),6 months after (T2) and at least 1 year after surgery (T3) were evaluated. The midsagittal cut of each implant was identified, horizontal facial bone thickness (HFBT) was measured at 0,25%,50%,75%, 100% of the implant length from implant shoulder. Vertical facial bone level (VFBL) referred in particular to the distance from the implant shoulder to the most coronal point of the facial bone. Gray value was detected from the cortical bone area of facial bone.Results:CBCT scans of 31 patients with 40 implants were analyzed, after functional loading of 6 to 18 months. During statistical analysis,2 implants (5%) in one patient were excluded since no detectable facial bone were found at T2.35 implants used Bio-Gide membrane in surgery, among which 15 used small particles and 20 used large particles of Bio-Oss. At T3, the mean HFBT ranged from 1.84 to 3.14mm at the five different levels were evaluated. The VFBL was 1.29± 1.23mm. HFBT changed 1.02±0.85mm (32.38%) from T1 to T2, and 0.39±0.92mm (10.09%) from T2 to T3, respectively. The gray value of facial bone significantly increased from T1 to T3. HFBT changes did not show any statistical difference between different timing of implant placement, neither between different particle types of Bio-Oss.Conclusions:Maxillary anterior implant placement with simultaneous GBR showed excellent outcomes with the small facial bone alterations. The labial bone density decreased from preoperation to postoperation, but continued to rise from postoperative day to 6 months, and 1 year, reflecting the new bone formation.