Graftless Periosteal Coverage Versus Xenogenic Graft for Jumping Gap Management in Immediate Mandibular Molar Implants

Lead sponsor

Horus University is the lead sponsor of 33 studies on the registry; 11 are open to participants now.

Study arms

• Active comparator
  Mucoperiosteal Coverage

  Immediate mandibular molar implant placement with management of the peri-implant jumping gap using a coronally advanced periosteal flap.

  Procedure: Coronally Advanced Periosteal Flap

• Active comparator
  Particulate Bone Graft & Collagen membrane

  Immediate mandibular molar implant placement with management of the peri-implant jumping gap using particulate xenogenic bone graft.

  Procedure: Particulate Xenogenic Bone Graft with Collagen Membrane

Interventions

• ProcedureCoronally Advanced Periosteal Flap

  Immediate mandibular molar implant placement with management of the peri-implant jumping gap using a coronally advanced periosteal flap. A minimally elevated buccal full-thickness flap will be followed by a deep-to-shallow periosteal releasing incision. The periosteum will be coronally advanced to completely cover the implant shoulder and jumping gap. The gap will be left to heal under the periosteal envelope without placement of bone graft or collagen membrane, followed by tension-free primary closure.

• ProcedureParticulate Xenogenic Bone Graft with Collagen Membrane

  Immediate mandibular molar implant placement with management of the peri-implant jumping gap using particulate xenogenic bone graft. The jumping gap will be filled with particulate xenogenic bone graft, which will be covered with a resorbable collagen membrane extending approximately 2-3 mm beyond the defect margins, followed by wound closure

Primary outcomes

1. Bone volume

   The volume of regenerated bone within the jumping gap surrounding the dental implant will be assessed using cone-beam computed tomography (CBCT). The regenerated bone volume will be measured in cubic millimeters (mm³) using standardized CBCT images and a predefined region of interest corresponding to the jumping gap. The volumetric measurements will be performed according to a standardized image-analysis protocol.

   Time frame: 4 months post-operatively

2. Bone density

   The radiographic density of the regenerated bone surrounding the dental implant will be assessed using cone-beam computed tomography (CBCT). Bone density will be measured in Hounsfield units (HU) within a predefined region of interest corresponding to the regenerated bone around the implant. Standardized CBCT acquisition and image-analysis protocols will be used to ensure consistency of measurements.

   Time frame: 4 months post-operatively

Secondary outcomes

1. Implant Stability

   Measurements will be obtained using an appropriate resonance frequency analysis device at the predefined assessment time points and expressed as an implant stability quotient (ISQ). The ISQ value, ranging from 1 to 100, will be recorded for each implant, with higher ISQ values indicating greater implant stability. For each implant, ISQ measurements will be obtained in two perpendicular directions, and the mean value will be calculated and used for statistical analysis.

   Time frame: Implant stability will be assessed at baseline and after 4 months

2. Post-operative pain

   Postoperative pain will be assessed using a 10-cm Visual Analogue Scale (VAS), ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst imaginable pain. Participants will record their pain intensity at the specified postoperative time points.

   Time frame: days 2, 7, and 14 post-operative

3. Patient-reported post-operative swelling

   Visual numeric rating scale (VNRS)/numeric scale for swelling, 0-10 numerical scale, which captures the patient's perception at 2, 7 and 14 days post-operative.

   Time frame: At 2, 7 and 14 days post-operative.

4. Postoperative complications

   The occurrence of postoperative complications, including membrane exposure, flap dehiscence, and postoperative infection, will be clinically assessed at each scheduled postoperative follow-up visit. Each complication will be recorded as present or absent (yes/no), and the date of occurrence will be documented. Membrane exposure will be assessed in participants receiving the collagen membrane, while flap dehiscence and postoperative infection will be assessed in both treatment groups.

   Time frame: Postoperative days 2, 7, and 14, and monthly thereafter through 4 months.

5. Objective facial swelling

   Standardized facial measurements in mm, will be measured at baseline + postoperative follow-ups. Postoperative facial swelling will be assessed using standardized facial linear measurements. Three facial distances (tragus to corner of mouth, tragus to pogonion, and angle of mandible to corner of mouth) will be measured preoperatively as baseline and postoperatively on days 2, 7 and 14 using a flexible measuring tape. All measurements will be performed by the same calibrated examiner using standardized anatomical landmarks and with the patient in a standardized seated position. The change in each facial measurement from baseline will be recorded as an objective measure of postoperative swelling.

   Time frame: Pre-operative (baseline), and then 2, 7 and 14 days post-operative

Study documents

• Protocol and statistical analysis plan · Mar 23, 2026

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No — Individual participant data will not be shared with other researchers because of ethical, privacy, and confidentiality considerations related to the limited sample size. Only aggregate, de-identified study results will be reported and made available through publication.