Effect of Two Incision Techniques on Soft and Hard Tissue Outcomes in Immediate Implant Placement in Class II Extraction Sockets of the Esthetic Zone:

This randomized controlled clinical trial investigates the effect of two different surgical approaches-Vestibular Socket Therapy (VST) and Flap Elevation Technique-on soft and hard tissue outcomes during immediate implant placement in Class II extraction sockets of the anterior maxilla (esthetic zone). The study enrolled 26 systemically healthy adult patients contributing a total of 48 surgical sites. Each site was randomly assigned to one of the two treatment groups. The VST group employed a minimally invasive vestibular incision to allow atraumatic extraction, implant placement, bone grafting, and membrane placement while preserving the labial soft tissue and periosteal blood supply. The Flap Elevation group followed a conventional intrasulcular flap approach. In both groups, implants were placed with 30 Ncm torque and augmented with MegaOss™ allograft and a resorbable collagen membrane (T-barrier™). Clinical and radiographic evaluations were conducted at baseline, 6 months, and 12 months post-loading. Outcomes measured included Pink Esthetic Score (PES), peri-implant probing depth (PD), mucosal level changes, and crestal bone level changes.

Tooth extraction in the anterior maxilla, particularly in the esthetic zone, often leads to substantial resorption of the alveolar ridge, predominantly affecting the thin buccal bone plate. Studies have shown that up to 50% of horizontal ridge width can be lost within 6 months of extraction, compromising both soft tissue contours and the feasibility of future implant placement (Araújo \& Lindhe, 2005; Schropp, Wenzel, Kostopoulos, \& Karring, 2003). This resorption has profound esthetic and functional implications, especially in patients with high smile lines or thin periodontal biotypes. To address these challenges, immediate implant placement was introduced to reduce treatment time, preserve socket dimensions, and optimize soft tissue outcomes (Kan, Rungcharassaeng, Umezu, \& Kois, 2003; Lang, Pun, Lau, Li, \& Wong, 2012). While immediate implants help maintain the overall ridge profile, they do not fully prevent bone remodeling of the buccal plate, which often results in soft tissue recession and compromised esthetic outcomes (Botticelli, Berglundh, Buser, \& Lindhe, 2003; Chen \& Buser, 2014). Flap design during implant surgery has been identified as a critical factor influencing peri-implant bone and soft tissue healing. The traditional flap elevation approach provides good visibility but disrupts the periosteal blood supply, increasing the risk of bone resorption and soft tissue shrinkage (Fickl et al., 2008; Jeong et al., 2007). By contrast, flapless surgery preserves the periosteal blood supply and minimizes soft tissue trauma, leading to superior bone preservation and reduced postoperative discomfort (Becker, Goldstein, Becker, \& Sennerby, 2005; Oh, Shotwell, Billy, \& Wang, 2006). However, flapless techniques carry limitations such as reduced access and increased risk of malpositioning the implant or causing thermal bone damage without adequate irrigation (Choudhary et al., 2023). To overcome the limitations of both approaches, Vestibular Socket Therapy (VST) was developed as a minimally invasive technique that allows simultaneous atraumatic extraction, implant placement, and socket augmentation through a small vestibular access incision (A. Elaskary et al., 2023). VST preserves the integrity of the labial soft tissues and periosteal blood supply, improves labial bone support, and enables simultaneous use of bone grafts and membranes to enhance both hard and soft tissue outcomes (Ghallab et al., 2023). Clinical trials comparing VST to conventional incisal extraction or partial extraction therapy (PET) have demonstrated comparable or superior outcomes in terms of Pink Esthetic Score (PES), soft tissue volume preservation, and facial bone thickness (A. Elaskary et al., 2023; Hamed et al., 2023). Bone grafting materials used in combination with immediate implants have also been extensively studied. While autogenous bone has been considered the gold standard, it is often limited by donor site morbidity. Alternatives such as deproteinized bovine bone mineral (DBBM), demineralized bone matrix (DBM), and collagen plugs have been successfully used to fill peri-implant defects and support labial bone regeneration (Araújo \& Lindhe, 2005; Artzi, Tal, \& Dayan, 2000; Jensen \& Terheyden, 2009). Randomized controlled trials have shown that using a combination of autogenous bone chips with DBBM (e.g., MinerOss X) significantly increases facial bone thickness compared to collagen plug or DBM alone (Hamed et al., 2023). Moreover, the Pink Esthetic Score (PES) has become a standard metric to assess esthetic outcomes around implants, evaluating parameters such as mesial and distal papilla fill, soft tissue level and contour, alveolar process deficiency, and tissue color and texture (Fürhauser et al., 2005). Studies have consistently shown that minimally invasive approaches, like VST and PET, score highly on PES, reflecting superior esthetic outcomes (Cosyn et al., 2011; Evans \& Chen, 2008). Vestibular socket therapy (VST) has emerged as a promising minimally invasive approach for preserving soft and hard tissue architecture during immediate implant placement, particularly in challenging esthetic zones. However, its clinical performance compared to conventional flap elevation remains underexplored. This study aims to evaluate the effectiveness of VST combined with Allograft and collagen membrane in enhancing esthetic outcomes, soft tissue stability, and bone preservation advancing minimally invasive protocols toward more predictable, patient-centered care.