Description

• Research question: Does screw tent pole technique provides better bone gain than autogenous bone block in atrophied anterior maxilla?

• Rationale for conducting the research: Several methods have been developed for the augmentation of the deficient bone volume. These include Guided Bone Regeneration (GBR) with barrier membranes, onlay bone grafting, ridge splitting and distraction osteogenesis.

The screw tent-pole method is an effective technique to achieve initial reconstruction of alveolar bone deficiencies. Previous studies have proven that screw tent pole technique is recommended in reconstruction of atrophied alveolar bone and its good outcome in contrary to other bone graft techniques.

This study aim to compare the outcome of screw tent pole technique to conventional gold standard technique of block bone grafts in atrophied anterior maxilla.

• Primary and secondary objectives:

• primary objective to assess amount of bone gain
• secondary objective assess bone quality . Trial design: Randomized clinical trial, Unicentered, Parallel groups, 2 arms, Allocation ratio 1:1, Equivalent trial • PICO: Population: patients with atrophied Anterior Maxillary area (with initial ridge width of ≤ 5 mm and moderate bone height) Intervention: Screw Tent-Pole technique Control group: Autogenous Bone Block technique Outcome: bone gain , histomorphometric evaluations, dehiscence.
• Interventions
• Surgical Protocol
  1. Screw Tent pole technique
• A prophylactic antibiotics administration was conducted.
• All surgical procedures were performed under local anesthesia.
• A trapezoid incision will be formed to expose the edentulous alveolar ridge in recipient site.
• A full-thickness flap will be retracted to expose the alveolar bone. 5
• Titanium screws (1.5 mm) will be placed perpendicular to alveolar bone so that approximately 5 to 7 mm of screw threat will be exposed.
• A posterior releasing incision was made over ramus to provide access to the donor site.
• Autogenous bone graft taken from donor site area using ACM bur
• The autogenous particles obtained from the donor site will be mixed with xenograft in a 50/50 ratio.
• PRF membrane is then prepared ( PRF membrane formed by withdrawing blood sample from patient into a tube , the tube will be transferred to centrifuge machine -2500 RPM for 10 minutes) and is pierced through the healing abutment and used to cover the bone graft to accelerate wound healing by preventing soft tissue ingrowth.
• A tension-free suture will be completed.
• After 6 months of healing:

A full-thickness flap is retracted to expose the alveolar bone (augmented site).

The screw will be removed, Histopathological biopsy sample of bone will be taken using trephine bur (the same size as pilot drill) and sequential drilling will be done for implant placement at the same visit.

B. Autogenous bone block technique

• A prophylactic antibiotics administration was conducted.
• All surgical procedures were performed under local anesthesia.
• A trapezoid incision will be formed to expose the edentulous alveolar ridge in recipient site.
• A full-thickness flap will be retracted to expose the alveolar bone.
• A posterior releasing incision was made over ramus to provide access to the donor site.
• The size of the ramus graft will be determined from the recipient site, and bone osteotomy of cortical and cancellous bone will be done by Piezo-electric bone surgery.
• The outlined graft was mobilized from its bed using chisels and the bone block will be placed in defected anterior maxilla and stabilized using micro screws.
• particulate Autogenous bone graft will also be taken from donor site area using ACM bur and mixed with xenograft in a 50/50 ratio and then placed to fill the space in between the bone block.
• PRF membrane is then prepared ( PRF membrane formed by withdrawing blood sample from patient into a tube , the tube will be transferred to centrifuge machine -2500 RPM for 10 minutes) and is pierced through the healing abutment and used to cover the bone graft to accelerate wound healing by preventing soft tissue ingrowth.
• A tension-free suture will be completed.
• After 6 months of healing:

A full-thickness flap is retracted to expose the alveolar bone (augmented site).

The screw will be removed, Histopathological biopsy sample of bone will be taken using trephine bur (the same size as pilot drill) and sequential drilling will be done for implant placement at the same visit.

• Post-operative care:

• Avoid traumatization of the surgical site.
• Patients must abstain from brushing the surgical area. Instead, a disinfecting mouth rinse should be used (e.g. chlorhexidine 0.2%).
• ·Instruct the patient not to touch or manipulate the surgical area.
• ·Ice packs for 10 minutes every 30 minutes for 24 hours.
• Do not use removable dentures during the expansion phase. Temporary fixed partial dentures must be adjusted to the expected tissue gain.
• ·No consume of tobacco
• ·Post-operative medications will be prescribed as follows:
• Amoxicillin/clavulanic acid tablets 10mg/kg every 12 hours for 7 days, diclofenac potassium 50mg every 8 hours for 4 days and then as needed, metronidazole 5 mg/kg every 8 hours for 7 days and chlorhexidine gluconate
• 0.1% mouthwash 3 times daily for 14 days.

Clinical follow up:

-The dehiscence will be followed up every month.

Radiographic follow up:

-Immediately after surgery and after six months, CBCT will be obtained to evaluate bone gain in each group