An interventional study of Bone augmentation using an autologous bone block and Bone augmentation using freeze-dried allograft block in Edentulous Alveolar Ridge and Edentulous Alveolar Ridge Atrophy, sponsored by Semmelweis University. Recruiting at 1 site in Hungary. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-10-03.
Sponsored by Semmelweis University · Not applicable, Interventional, and Treatment
After tooth loss, the alveolar ridge undergoes various modeling and remodeling processes, resulting in overall bone resorption. In case of extensive alveolar atrophy, bone volume must be restored before or during implant placement to achieve successful dental rehabilitation and maximize implant survival and success rates. One possible method for reconstructing severe bone resorption is block bone augmentation.
Due to its biological properties, autologous bone is considered the "gold standard" among bone graft materials, as it possesses osteoinductive, osteoconductive, and osteogenic properties.
The advantages of using allografts over autologous bone grafts include reduced postoperative morbidity, decreased surgical time, and the absence of anatomical limitations regarding the amount of bone that can be harvested. The disadvantage of allografts is the loss of viable osteogenic cells and osteoinductive factors during processing.
The aim of the study is:
Semmelweis University is the lead sponsor of 136 studies on the registry; 54 are open to participants now.
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A freeze-dried bone allograft block is used for the lateral augmentation of the atrophied jaw.
Procedure: Bone augmentation using freeze-dried allograft block · Diagnostic Test: preoperative cone beam computed tomography (CBCT) · Diagnostic Test: post-operative cone beam computed tomography (CBCT) · Procedure: Dental implant placement · Diagnostic Test: Bone core biopsy · Procedure: Fixed dental prosthesis (FDP) fabrication · Device: Bone grafting
An autogenous bone block harvested from the retromolar area of the mandible is used for the lateral augmentation of the atrophied jaw.
Procedure: Bone augmentation using an autologous bone block · Diagnostic Test: preoperative cone beam computed tomography (CBCT) · Diagnostic Test: post-operative cone beam computed tomography (CBCT) · Procedure: Dental implant placement · Diagnostic Test: Bone core biopsy · Procedure: Fixed dental prosthesis (FDP) fabrication
* Under local anesthesia, a crestal and mesial releasing incision is made, followed by preparation of a full-thickness mucoperiosteal flap. * In the control group, an autologous bone block graft is harvested from the retromolar donor area using rotary instruments and piezoelectric surgery. * The block is fixed to the recipient site with two screws. * The flap is mobilized, and the wound is closed tension-free with mattress and simple interrupted sutures. * Sutures are removed two weeks postoperatively. * All patients receive therapeutic-dose antibiotics: amoxicillin and clavulanic acid 2x1 for one week. In the case of an amoxicillin allergy, clindamycin 4x1 for seven days is administered. Non-steroid anti-inflammatory treatment with diclofenac 3x1 is also provided. * Patients do not wear temporary prostheses during the healing period.
* Under local anesthesia, a crestal and mesial releasing incision is made, followed by preparation of a full-thickness mucoperiosteal flap. * In the test group, a freeze-dried allograft bone block is prepared to the required size using rotary instruments. * The block is fixed to the recipient site with two screws. * The flap is mobilized, and the wound is closed tension-free with mattress and simple interrupted sutures. * Sutures are removed two weeks postoperatively. * All patients receive therapeutic-dose antibiotics: amoxicillin and clavulanic acid 2x1 for one week. In case of amoxicillin allergy, clindamycin 4x1 for seven days is administered. Non-steroid anti-inflammatory treatment with diclofenac 3x1 is also provided. * Patients do not wear temporary prostheses during the healing period.
• Preoperatively, a CBCT scan is performed to assess inflammatory and other pathological changes and anatomical variations in the dentomaxillofacial region.
Postoperatively, a CBCT scan is performed to assess bone quantity and quality before implantation.
Following the 3-month-long healing period following bone augmentation, dental implants are placed non-submerged in the augmented bone under local anaesthesia.
At the time of dental implant placement, a rotary instrument is used to harvest a bone core biopsy sample from the augmented bone. The bone core biopsy samples are subjected to histomorphometric and microCT analysis.
After 3 months of dental implant placement, fixed dental prosthesis are delivered on the dental implants.
Freeze-dried bone allograft block
Success of the bone augmentation
The bone augmentation surgery is successful if no inflammatory complications occur in the 3-month healing period and the bone volume is sufficient for dental implant placement.
Time frame: 3 months
Success of the dental implants
According to The International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference. I. Success (optimum health) 1. No pain or tenderness upon function 2. 0 mobility 3. Less than 2 mm radiographic bone loss from initial surgery 4. No exudates in the patient's history II. Satisfactory survival 1. No pain on function 2. 0 mobility 3. 2-4 mm radiographic bone loss 4. No exudates in the patient's history III. Compromised survival 1. May have sensitivity to the function 2. No mobility 3. Radiographic bone loss of more than 4 mm (less than1/2 of the length of the implant body) 4. Probing depth more than 7 mm 5. May have exudates in the patient's history IV. Failure (clinical or absolute failure) Any of the following: 1. Pain on function 2. Mobility 3. Radiographic bone loss of more than 1/2 the length of the implant 4. Uncontrolled exudate 5. Implant no longer in the mouth
Time frame: 3 months
Success of the implant-borne prostheses
Prostheses with four or fewer complications (screw loosening, decementation, chipping) that could be treated chairside.
Time frame: 5 years
Hisomorphometry: Percent of residual bone graft particles
The percentage of residual bone graft particle area measured on the representative sections prepared from the bone core biopsy samples. Unit: percent (%)
Time frame: 3-6 months
Hisomorphometry: Percent of newly formed bone
The percentage of newly formed bone area is measured on the representative sections prepared from the bone core biopsy samples. Unit: percent (%).
Time frame: 3-6 months
Hisomorphometry: Percent of bone marrow
The percentage of bone marrow area measured on the representative sections prepared from the bone core biopsy samples. Unit: percent (%)
Time frame: 3-6 months
Value of the percent bone volume (BV/TV) calculated from the microCT reconstructions of the bone core biopsy samples
Relative volume of calcified tissue in the selected volume. Unit: none
Time frame: 3-6 months
Value of the bone surface to volume ratio (BS/TV), calculated from the microCT reconstructions of the bone core biopsy samples
Ratio of the segmented bone surface to the total volume in the region of interest. Unit: 1/mm
Time frame: 3-6 months
Value of the trabecular thickness (Tb.Th.) calculated from the microCT reconstructions of the bone core biopsy samples.
Mean thickness of the trabeculae, assessed using direct 3D methods. Unit: mm.
Time frame: 3-6 months
Value of the trabecular separation (Tb.Sp.), calculated from the microCT reconstructions of the bone core biopsy samples.
Mean distance between the trabeculae, assessed using direct 3D methods. Unit: mm.
Time frame: 3-6 months
Value of the trabecular bone pattern factor (Tb.Pf), derived from microCT reconstructions of bone core biopsy samples.
An indicator of the relation between convex and concave elements in the trabecular bone structure. Tb.Pf \<0 when the trabecular bone is honeycomb-like and increases as the trabecular bone acquires a rod-like structure. Unit: none.
Time frame: 3-6 months
Value of the structure model index (SMI), calculated from the microCT reconstructions of the bone core biopsy samples.
The estimator of the plate-versus rod-like characteristic of the trabecular bone structure, 0 for perfect plates, 3 for perfect rods, and 4 for perfect spheres. Unit: none.
Time frame: 3-6 months
Value of the Total porosity (Po(tot)), calculated from the microCT reconstructions of the bone core biopsy samples.
Percent porosity is the volume of pores as a percent of the total volume of interest (VOI). Unit: percent (%).
Time frame: 3-6 months
Value of the Connectivity (Conn), calculated from the microCT reconstructions of the bone core biopsy samples.
One useful and fast algorithm for calculating the Euler connectivity in 3D is the "Conneulor". It measures what might be called "redundant connectivity", the degree to which parts of the object are multiply connected. It is a measure of how many connections in a structure can be severed before the structure falls into two separate pieces. Unit: none.
Time frame: 3-6 months
Plan to share: Yes — Individual participant data that underlie the results published after de-identification.
Supporting information: Study protocol
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