Bone Substitutes, Connective Tissue Graft, Immediate Dental Implant Placement
Conditions
Keywords
Bone substitutes, connective tissue, dental implant, hard tissues, soft tissue, tooth extraction, tooth socket
Brief summary
This study aims to assess hard and soft tissue changes after immediate implant placement, comparing the use of a deproteinized bovine bone mineral and sub-epithelial connective tissue graft in the management of the buccal gap. This study involves clinical and radiographic evaluation to assess tissue changes following immediate implant placement. Preoperative procedures include a clinical diagnosis, clinical measurements, intraoral scanning, and CBCT analysis. After flap elevation, atraumatic extraction is performed followed by immediate implant placement. Buccal gap management is done using either a deproteinized bovine bone mineral or a connective tissue graft (placed on the flap). Postoperative assessments, including intraoral scans and CBCT imaging, are conducted at six months. To evaluate hard and soft tissue changes, the scans and CBCTs are superimposed using a digital software to quantify differences and statistical analysis is then performed
Detailed description
Dental implant treatment has become crucial in dentistry, evolving with advancements in biomaterials and techniques to ensure not only implant survival but also long-term esthetic and functional success. A classification system for implant placement in relation to the extracted tooth was proposed by the ITI's Third Consensus Conference. Type I is defined as the placement of an implant immediately after tooth extraction : immediate implant placement (IIP). IIP has several advantages, including fewer surgical interventions and a shorter overall treatment duration. It also achieves high survival rates in comparison with delayed implant placement, at 98.5% and 98.9%, respectively. Horizontal and vertical ridge alterations are observed after IIP, as several studies have shown that IIP per se doesn't prevent alveolar ridge reduction. Seyssens et al.'s 10-year prospective case series showed that 3 out of 18 cases had no detectable buccal bone, indicating the possible limitations of IIP in preserving bone volume. The alveolar socket's dimensions exceed the implant's diameter, creating a gap between the coronal portion of the implant and the surrounding bone, referred to as the "fixture-socket gap." Altough this gap may close in some cases, studies have shown that it typically does not fill completely without the use of biomaterials. In the aesthetic zone between the second contralateral premolars, the size of the gap at the buccal aspect is important for minimizing bone alterations, as the buccal bone plate is prone to resorption, which can lead to soft tissue recession. Studies demonstrate that buccal gaps ≤ 2 mm can heal without the need for grafts or barriers, while gaps \>2 mm are unlikely to achieve complete bone fill as larger gaps may affect spontaneous bone healing. Chen et al. and Grassi et al. reported no significant impact of gap size on horizontal buccal bone resorption after IIP with or without socket grafting (SG). In fact, the dimensions of the gap and the approach for managing it remains debated with uncertainty about the procedures to minimize buccal bone resorption and soft tissue recession. Several studies showed that the use of biomaterials such as xenografts in the fixture-socket preserve socket volume and reduces the bone dimensional changes that occurs following IIP. A meta-analysis showed 0.59 mm (or 54%) less horizontal buccal bone resorption with IIP combined with SG compared to IIP alone. Using a connective tissue graft (CTG) at the buccal aspect of immediate implants is an another regenerative approach that has been shown in a recent systematic review to reduce apical migration of the mid facial soft tissue level by 0.41 mm. Increased soft tissue thickness may protect against bone resorption, according to recent studies. A pilot study by Aroca et al. found that placing a CTG during IIP without SG reduces horizontal changes in the alveolar ridge and preserves tissue contour but doesn't affect vertical bone resorption. Combining IIP with a CTG could be an effective option to address hard tissue changes and maintain tissue aesthetics.
Interventions
Before surgery, patients will rinse with 0.12% chlorhexidine solution for one minute. Local anesthesia will be administered using 2% articaine with 1:100,000 epinephrine. A 15c (Swann-Morton®) blade is used to make the incision, and the flap is elevated. The tooth will be extracted atraumatically to preserve the buccal ridge, using a periotome and, if feasible, rotational forceps. Elevators will be used when necessary, ensuring no pressure applied to the vestibular plate. The implant site is prepared following the manufacturer's drilling sequence to achieve primary stability (\>35 Ncm). After implant placement, the fixture-socket gap will be addressed based on group assignment: • Control Group: The buccal gap will be filled with a deproteinized bovine bone mineral (DBBM) (OCS-B®, NIBEC, Korea ).
Before surgery, patients will rinse with 0.12% chlorhexidine solution for one minute. Local anesthesia will be administered using 2% articaine with 1:100,000 epinephrine. A 15c (Swann-Morton®) blade is used to make the incision, and the flap is elevated. The tooth will be extracted atraumatically to preserve the buccal ridge, using a periotome and, if feasible, rotational forceps. Elevators will be used when necessary, ensuring no pressure applied to the vestibular plate. The implant site is prepared following the manufacturer's drilling sequence to achieve primary stability (\>35 Ncm). After implant placement, the fixture-socket gap will be addressed based on group assignment: • Test Group 1 : The gap will be left empty, and a sub-epithelial connective tissue graft will be harvested from the palate then de-epithelialized. The CTG will be sutured to the flap
Sponsors
Study design
Intervention model description
Primary objective : To assess radiologically the vertical buccal bone dimensional changes six months after immediate implant placement, comparing the use of a deproteinized bovine bone mineral, sub-epithelial connective tissue graft and collagen matrix in the buccal gap. Secondary objectives : * To assess radiologically after immediate implant placement, comparing the use of a deproteinized bovine bone mineral and sub-epithelial connective tissue graft in the buccal gap (at six months): * The horizontal buccal bone dimensional changes * The horizontal soft tissue thickness changes * The volumetric soft tissue changes * To assess the buccal gap dimensions on the buccal bone changes.
Eligibility
Inclusion criteria
* Adult patients (≥18 years of age) * Single hopless tooth in need for extraction in the maxillary or mandible area from second premolar to second premolar * Intact extraction socket; in the event of a potential facial fenestration, this should be no more than 3 mm apical from the marginal bone crest. * Buccal bone plate thickness ≥ 1.5 mm. * Sufficient apical bone to attain implant primary stability (a minimum of 35 N cm insertion torque)
Exclusion criteria
* \- Pregnant or lactating women * Patients with systemic diseases or inflammatory and autoimmune diseases affecting the oral cavity * Infected socket or periapical pathosis * History of radiotherapy or chemotherapy within the past 2 years * General contraindications for dental or surgical treatments * Uncontrolled diabetes * Concurrent or previous immunosuppressant, bisphosphonate, or high-dose corticosteroid therapy * Unable or unwilling to return for follow-up or comply with study procedures
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in vertical buccal bone height (mm) from baseline to 6 months | Baseline and 6 months | Measured on CBCT superimposition as the vertical linear distance (VLD) between the buccal crest at baseline and 6 months along the implant axis. Negative values indicate resorption. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in horizontal buccal bone thickness (mm) from baseline to 6 months | Baseline and 6 months | Measured on CBCT superimposition at 1-5 mm apical to the implant platform. |
| Change in buccal soft tissue thickness (mm) from baseline to 6 months | Baseline and 6 months | Measured by STL/CBCT superimposition at 1-5 mm apical to the gingival margin. |
| Percentage change in buccal soft tissue volume (%) from baseline to 6 months | Baseline and 6 months | Calculated from superimposed STL datasets. |
| Buccal gap width (mm) at implant placement and its association with bone changes at 6 months | Perioperative (Day 1) and 6 months | S-IC and S-OC measured clinically at surgery and correlated with bone changes. |
Countries
Lebanon