Alveolar Bone Grafting, Bone Substitutes
Conditions
Keywords
Alveolar Bone Atrophy, Bone Substitutes, Bone Resorption
Brief summary
This study will compare three methods to rebuild lost bone in the back part of the lower jaw (posterior mandible) before dental implant placement. Seventy-eight adults will be randomly assigned to receive one of three "cortical shell" techniques using either the patient's own bone (autogenous) or prefabricated bone plates from animal (xenogeneic) or human donors (allogeneic). In all groups, the space inside the shell will be filled with a mixture of small bone chips and bone substitute material. The main outcome is the increase in jawbone width measured on 3D cone-beam CT scans at 6 months after surgery. Additional scans and clinical assessments up to 12 months will evaluate healing, bone stability, and postoperative recovery.
Interventions
PROCEDURECortical Shell Bone Grafting
Surgical reconstruction of atrophic posterior mandibular ridges using thin cortical plates fixed with titanium microscrews to form a biologic shell. The inner space is filled with a 1:1 mixture of autogenous bone chips and biomaterial. Depending on the study group, the cortical plates are autogenous (from the mandibular ramus), xenogeneic (bovine origin), or allogeneic (human donor).
Sponsors
Universidad de Especialidades Espiritu Santo
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Masking description
This is an open-label surgical trial. Due to the nature of the interventions, participants, surgeons, and investigators cannot be blinded. The statistician responsible for the primary analysis will remain blinded to group allocation until completion of the primary analysis.
Intervention model description
A randomized, statistician-blinded, parallel-group clinical trial will be conducted in 78 participants presenting with posterior mandibular bone atrophy. Participants will be allocated in a 1:1:1 ratio to receive autogenous, xenogeneic, or allogeneic cortical shell augmentation. Each participant will receive only one allocated intervention, and the unit of analysis for the primary endpoint will be the participant.
Eligibility
Sex/Gender
ALL
Age
18 Years to 64 Years
Healthy volunteers
Yes
Inclusion criteria
Posterior mandibular edentulism requiring horizontal ridge augmentation (Cawood \& Howell Classes IV-VI). One or two eligible posterior mandibular sites suitable for cortical shell augmentation. Adequate residual bone height to allow safe fixation above the mandibular canal. Good general health (ASA I or II). Plaque index \< 20% and absence of active periodontal infection. Ability and willingness to attend scheduled follow-up visits (up to 12 months). Written informed consent provided prior to any study-related procedure.
Exclusion criteria
Uncontrolled systemic diseases affecting bone healing (e.g., uncontrolled diabetes mellitus, immunosuppressive disorders). Current heavy smoking (\>5 cigarettes/day). Pregnancy or lactation. Current use of medications known to affect bone metabolism or healing (e.g., bisphosphonates, long-term corticosteroids, anticoagulants). Active periodontal disease or untreated oral infection. History of chemotherapy or radiotherapy to the head and neck region.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Horizontal Bone Gain (mm) Measured by CBCT | 6 after surgery | Participant-level horizontal bone gain at 6 months after surgery, measured on cone-beam computed tomography (CBCT) scans using standardized reference points. When two eligible posterior mandibular sites are treated in the same participant, the participant-level mean will be used for the primary analysis. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Surgical Duration (minutes) | Day 0 (intraoperative measurement) | Total surgical time for each bone augmentation procedure, measured from the first anesthetic injection to the final suture. Timing will be recorded using a standardized chronometer to compare operative efficiency across autogenous, xenogeneic, and allogeneic cortical shell techniques. |
| Relative Radiographic Density Using CBCT Gray Value Units | 3, 6, and 12 months after surgery | Relative radiographic density within the grafted area will be assessed using device-specific CBCT gray value measurements under standardized acquisition parameters. These values will not be interpreted as calibrated Hounsfield Units. Measurements will be performed by calibrated examiners. |
| Postoperative Inflammation (mm Facial Measurement) | Preoperative, immediate postoperative, days 3, 7, and 14 | Postoperative swelling will be assessed by measuring the linear distance from the lip commissure to the tragus with a flexible tape. Measurements will be taken bilaterally under standardized conditions by the same examiner to evaluate differences among groups. |
| Volumetric Bone Gain (mm³) | 3, 6, and 12 months after surgery | Three-dimensional volumetric changes of the augmented area will be calculated by superimposing pre- and postoperative CBCT-derived meshes using surface registration software. The difference in total reconstructed volume (ΔVolume) will quantify the amount of new bone formation across techniques. |
| Morphometric Surface Deviation (mm) | 3, 6, and 12 months after surgery | Surface deviation between pre- and postoperative 3D models will be analyzed using color-coded distance maps and point-to-surface metrics (mean absolute distance, RMS error, and 95th-percentile distance). This quantifies contour stability and remodeling patterns for each graft material. |
| Secondary Horizontal Bone Gain at 3 and 12 Months | 3 and 12 months after surgery | Horizontal bone gain measured on CBCT scans at 3 and 12 months after surgery will be analyzed as a secondary longitudinal outcome. |
Countries
Ecuador
Contacts
CONTACTAntonio G Lanata-Flores
Outcome results
None listed