Hard and Soft Tissue Changes Following Immediate Implant Placement With Buccal Gap Management: Comparing the Use of Deproteinized Bovine Bone Mineral Socket Grafting and Sub-epithelial Connective Tissue Graft in a 6-month Pilot Study.

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.

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