Four Different Guided Bone Regeneration Strategies for Horizontal Ridge Augmentation in the Maxillary Esthetic Zone With Simultaneous Implant Placement: a Randomized Clinical Trial

Horizontal alveolar ridge deficiency following tooth extraction is a common clinical challenge, particularly in the maxillary esthetic zone, where adequate bone volume is essential for optimal dental implant positioning and esthetic rehabilitation. Guided bone regeneration (GBR) techniques and different bone grafting materials have been developed to improve alveolar ridge dimensions and support successful implant placement. However, comparative clinical evidence regarding different augmentation strategies remains important for selecting appropriate regenerative approaches.

This prospective, randomized, four-arm clinical trial will be conducted at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mansoura University, Egypt.

A total of 40 patients requiring dental implant rehabilitation in the anterior maxilla with horizontal alveolar ridge deficiency (Siebert Class I) will be recruited. Participants will be randomly allocated to four equal groups using a computer-generated block randomization sequence with a fixed block size of four. The allocation sequence will be prepared by an independent investigator who will not participate in patient enrollment, surgical treatment, or outcome assessment.

All participants will undergo preoperative clinical and radiographic assessment, including cone-beam computed tomography (CBCT) for surgical planning. Under local anesthesia, a full-thickness mucoperiosteal flap will be elevated, and dental implants will be inserted into their planned prosthetic positions. Horizontal ridge augmentation will then be performed according to group allocation.

Group I: Titanium Mesh-Guided Bone Regeneration

Ten patients will receive horizontal ridge augmentation using a xenogeneic bone graft supported by titanium mesh. The mesh will be adapted to the defect and stabilized using fixation screws to maintain space and support bone regeneration.

Group II: Extended Sticky Bone

Ten patients will receive extended sticky bone (ESB), prepared by combining platelet-rich fibrin components, thermally processed plasma-derived albumin gel, and xenogeneic bone graft particles. The resulting cohesive graft material will be adapted around the dental implant to reconstruct the horizontal ridge defect.

Group III: Medpark Bone Graft

Ten patients will receive horizontal ridge augmentation using Medpark, a xenogeneic bone substitute with a moldable consistency following hydration. The graft will be adapted to the defect to augment alveolar ridge width.

Group IV: Ethoss Synthetic Bone Graft

Ten patients will receive horizontal ridge augmentation using Ethoss, a synthetic bone substitute composed of beta-tricalcium phosphate and calcium sulfate. The graft will be hydrated with sterile saline, applied to the defect, and allowed to harden.

In all groups, the graft material will be contoured to the desired ridge dimensions, followed by tension-free primary soft tissue closure.

Postoperative follow-up will include clinical assessment of wound healing and implant stability. A second-stage surgical procedure will be performed after six months to expose the implants and place healing abutments, followed by prosthetic rehabilitation using zirconia crowns.

Implant stability will be evaluated immediately after implant placement and at six months using resonance frequency analysis (RFA), expressed as Implant Stability Quotient (ISQ) values.

Soft tissue healing will be assessed using the Landry Healing Index at two weeks, four weeks, three months, and six months postoperatively.

Radiographic assessment will be performed using CBCT at baseline (T0), immediately after surgery within one week (T1), and six months postoperatively (T6). Three-dimensional volumetric analysis will be used to determine bone volume changes, including initial bone gain, six-month bone gain, and changes in augmented bone volume during healing.

Statistical analysis will be conducted using SPSS version 26. Data distribution will be assessed using the Shapiro-Wilk test. Parametric or nonparametric statistical tests will be selected according to data distribution, and categorical variables will be analyzed using appropriate categorical tests. Statistical significance will be set at p ≤ 0.05.

The study will compare the clinical and radiographic performance of four bone regeneration strategies to provide evidence supporting the selection of augmentation techniques during simultaneous dental implant placement in the maxillary esthetic zone.

• Titanium Mesh-Guided Bone Regeneration (Procedure): Horizontal ridge augmentation will be performed using a xenogeneic bone graft (GARANTIE, GmbH, Germany) supported by titanium mesh. The mesh will be stabilized buccally and palatally using 1.4 mm fixation screws following simultaneous implant placement.
• Extended Sticky Bone Augmentation (Procedure): Extended sticky bone will be prepared using platelet-rich fibrin, thermally processed plasma-derived albumin, and xenogeneic bone graft (GARANTIE, GmbH, Germany). The graft will be applied around the simultaneously placed dental implant to reconstruct the horizontal ridge deficiency.
• Medpark Bone Graft Augmentation (Procedure): Horizontal ridge augmentation will be performed using Medpark xenogeneic bone graft (Medpark Regeneration, Seoul, Republic of Korea). The graft will be hydrated and adapted to the defect site following simultaneous dental implant placement.
• Ethoss Synthetic Bone Graft Augmentation (Procedure): Horizontal ridge augmentation will be performed using Ethoss synthetic bone graft composed of beta-tricalcium phosphate and calcium sulfate. The material will be hydrated with sterile saline, adapted to the defect around the simultaneously placed dental implant, and allowed to harden using sterile gauze for 3-5 minutes.

Primary outcomes

• Change in Alveolar Bone Volume From Baseline to 6 Months [Baseline (preoperative) and 6 months postoperatively]: Three-dimensional alveolar bone volume will be assessed using cone-beam computed tomography (CBCT) before surgery (T0) and at 6 months postoperatively (T6). Bone volume gain will be calculated as the difference between bone volume at 6 months and baseline (T6 - T0). The outcome will be compared among the four treatment groups.

Secondary outcomes

• Change in Implant Stability Quotient (ISQ) From Implant Placement to 6 Months [immediately after implant placement and at 6 months postoperatively.]: Implant stability will be assessed using resonance frequency analysis (RFA) with an Osstell device. Implant Stability Quotient (ISQ) values will be recorded immediately after implant placement and at 6 months postoperatively. Change in stability will be calculated as the 6-month ISQ value minus the initial ISQ value. Higher ISQ values indicate greater implant stability.
• Soft Tissue Healing Assessed by the Landry Healing Index [2 weeks, 4 weeks, 3 months, and 6 months postoperatively.]: Postoperative soft tissue healing will be evaluated using the Landry Healing Index, based on tissue color, bleeding on palpation, presence of granulation tissue, incision margin condition, and degree of epithelialization. Healing will be assessed at 2 weeks, 4 weeks, 3 months, and 6 months following surgery.
• Initial Alveolar Bone Volume Gain [Preoperatively and within 1 week postoperatively]: Three-dimensional bone volume will be measured using cone-beam computed tomography (CBCT) preoperatively (T0) and within one week after surgery (T1). Initial bone volume gain will be calculated as T1 minus T0.
• Change in Augmented Bone Volume During Healing [Within 1 week postoperatively and at 6 months.]: Bone volume will be assessed using CBCT immediately postoperatively (T1) and at 6 months (T6). The change will be calculated as T6 minus T1, with negative values indicating bone volume loss.

Sex: All, ages: 18 Years to 45 Years

Inclusion Criteria:

* Patients aged 18-45 years.

Good oral hygiene.

Presence of horizontal alveolar ridge deficiency in the anterior maxilla (Siebert Class I).

Absence of deep undercuts on the buccal aspect of the alveolar ridge.

Presence of at least 3 mm of keratinized gingiva.

Adequate inter-arch space for dental implant rehabilitation.

Ability to comply with scheduled follow-up visits.

Exclusion Criteria:

* Patients with systemic conditions contraindicating surgery or dental implant placement.

Smokers.

Pregnant women.

Patients with parafunctional habits, such as bruxism.

Patients with local pathological conditions affecting bone healing.