Evaluation of Marginal Bone Loss Using Computer Guided Ridge Splitting Technique With Simultaneous Implant Placement.

All the procedures will perform under local anesthesia (mepivacain with levonordefrin). Horizontal Atrophic maxillary sectors will use for the development of the treatment sequence. All the patients will prepare initially with study models that permitted surgical and prosthetic planning as well as the non-strict surgical guide for intraoperative use. After application of conventional local anesthesia techniques, a full thickness incision 3 line pyramidal flap will be expose the defect ridge. The incision will extend to the next tooth or at least 5 mm more posterior from the end of the osteotomy indicated, securing direct observation of the alveolar crest.

With a direct view of the alveolar crest, if the ridge presented a width close to 1.5 mm, the ARST was performed immediately; if it presented less than 1.5 mm, then it was worn down with a diamond bur (low speed motor at 1800 rpm) to reduce the height, obtaining an improved alveolar crest width up to approximately 1.5 mm.

With this condition the bone splitting technique could be performed using the piezoelectric system (Piezotome2¨, Satelec Action, France), calibrating the device on the D1 setting and using profuse saline irrigation. The preparation sequence was begun with the CS3 insert until a total depth of 10 mm was achieved across the entire extension of the ridge. The procedure continued with the CS1 insert and finally the CS2 insert. The CS% insert was used in two patients with the possibility of widening the osteotomy segment; this sequence always achieved a complete extension in depth of application.

In the study group the vertical bone cuts through the cortical layer.

• At the distal end of the horizontal split: a vertical cut was made with the high-speed bur within the vicinity of the buccal plate of bone; for the start of the separation. With a full vertical depth of 13 mm. Final design of the splitting cut was (L-SHAPE) SPLIT The control group the vertical bone cuts through the cortical layer.
• At the distal and mesial end of the horizontal split: a vertical cut was made with the high-speed bur within the vicinity of the buccal plate of bone; for the start of the separation. With a full vertical depth of 13 mm corresponding and joining the previous vertical cut.

Using the expander to do the implants bed.-Preparation of the implant bed in the mesial end of the horizontal split using the spreading kit.-The final size spreader in the first implant osteotomy site with the first spreader in the second implant bed 3 mm apart. Dental implant placement. Placing the first implant in place while the separation kept preserved .placing the last spreader in the second implant osteotomy site. Bone deficiency is addressed by filling with osteoplastic material; a bio resorbing barrier membrane is arranged.

CBCT assessment For the calculation of marginal bone loss(MBL), the implant will use as a reference by adjusting the cross-sectional long axis in the center of the implant and bisecting it (showing the buccolingual and mesiodistal dimensions). On the cross-sectional view, a line will draw just parallel to the implant, starting at the crest of the labial plate of bone and ending at the apical level of the implant; height will recorded in millimeters. The same process was repeated from the palatal direction. The panoramic view (longitudinal cut) will utilized to calculate the mesial and distal bone heights in millimeters.