After tooth extraction, the alveolar bone, which supports the teeth, undergoes a natural resorption process. This bone loss can be significant, especially in the first few months post-extraction, leading to a reduction in both bone height and width. This resorption can compromise the structural foundation required for future dental restorations, such as implants, bridges, or dentures.

Socket preservation technique has been proposed since years as a technique to preserve alveolar bone following extraction and has proved excellent clinical efficacy over years.

Several materials have been proposed for alveolar ridge preservation, such as autografts, allografts, xenografts, and alloplasts, each with its own set of advantages and limitations. However, these materials may have limitations, including potential immunogenic responses and variable integration.

Thus, there is always a need to explore and validate new materials to mitigate these issues. This study aims to tests one of these new materials named chitosan gel to investigate whether the application of this chitosan gel following posterior mandibular tooth extraction would better preserve alveolar ridge dimensions and improve bone quality compared to normal socket healing or not ?.

Tooth extraction often leads to significant alveolar ridge resorption, which can complicate future dental implant placement and prosthetic rehabilitation . Socket preservation techniques aim to mitigate these dimensional changes, and various materials have been investigated for this purpose .

Chitosan, a natural biopolymer derived from chitin, has shown promising results in tissue engineering and regenerative medicine due to its biocompatibility, biodegradability, and antimicrobial properties.

Previous studies have demonstrated that chitosan can enhance bone regeneration and wound healing, making it a potential candidate for socket preservation. However, there is limited clinical evidence comparing chitosan to natural socket healing in the context of alveolar ridge preservation.

This trial aims to fill this gap by conducting a detailed histomorphometric analysis and assessing alveolar ridge dimensional changes post-extraction. Histomorphometric analysis will provide insights into the quality and quantity of new bone and soft tissue formation, offering a microscopic evaluation of the regenerative process. By comparing these parameters between chitosan-treated sockets and those that heal naturally, the study seeks to determine if chitosan can better preserve ridge dimensions and improve tissue regeneration quality.

The findings from this trial could have significant clinical implications, potentially leading to improved socket preservation techniques and materials. Enhanced preservation of the alveolar ridge could reduce the need for additional grafting procedures, facilitate easier and more predictable implant placement, and ultimately improve patient outcomes.

Therefore, this study aims to provide high-quality scientific evidence on the efficacy of chitosan gel in socket preservation, contributing to the existing body of knowledge and guiding future clinical practices.

Review of literature:

Tooth extraction is a common dental procedure that often leads to significant changes in the alveolar ridge, the bony structure that supports the teeth. Understanding the extent and nature of these changes is crucial for planning subsequent dental treatments, such as implant placement and prosthetic rehabilitation.

The alveolar ridge undergoes both horizontal and vertical resorption following tooth extraction. This resorption is a natural physiological response to the loss of the tooth and its associated periodontal ligament, which plays a crucial role in maintaining alveolar bone integrity. The absence of mechanical stimulation from the tooth leads to bone remodeling and resorption.

Several studies have quantified the dimensional changes in the alveolar ridge post-extraction. Araújo and Lindhe conducted an experimental study in dogs and found that the majority of bone loss occurs within the first three months following extraction. They reported an average horizontal bone loss of 3.8 mm and vertical bone loss of 1.24 mm within six months. These findings were corroborated by Tan et al, who conducted a systematic review and reported similar magnitudes of bone loss in humans.

Several factors can influence the extent of alveolar ridge resorption, including the patient's age, systemic health, smoking status, and the presence of periodontal disease. For instance, patients with uncontrolled diabetes or those who smoke are at a higher risk of accelerated bone loss. Additionally, the surgical technique used during extraction, such as flapless versus flap procedures, can also impact the degree of resorption.

To mitigate alveolar ridge resorption, various socket preservation techniques have been developed. These techniques involve the use of grafting materials and barriers to maintain the ridge dimensions post-extraction. Darby et al. reviewed different ridge preservation techniques and concluded that they can significantly reduce the amount of bone loss compared to natural healing. Common materials used for socket preservation include autografts, allografts, xenografts, and alloplasts, each with its own set of advantages and limitations.

Socket preservation techniques are employed to mitigate the alveolar ridge resorption that typically follows tooth extraction. These techniques aim to maintain the ridge dimensions, thereby facilitating future dental implant placement and improving prosthetic outcomes.

Autografts, which are taken from the patient's own body, typically from intraoral sites like the mandibular ramus or chin, and are considered the gold standard due to their osteogenic potential, though their use is limited by donor site morbidity and availability. Allografts, sourced from human donors and processed for sterilization, such as freeze-dried bone allograft (FDBA), are widely used for their osteoconductive properties and availability, significantly reducing ridge resorption compared to extraction alone.

Xenografts, derived from other species like bovine bone, such as deproteinized bovine bone mineral (DBBM), offer osteoconductive properties and slow resorption rates, providing long-term volume stability.

Alloplasts, synthetic graft materials including hydroxyapatite, beta-tricalcium phosphate (β-TCP), and bioactive glass, are biocompatible and osteoconductive, offering an alternative to biological grafts without the risk of disease transmission

Barrier membranes are often used in conjunction with grafting materials to prevent the ingrowth of soft tissue into the socket and to maintain space for bone regeneration. These membranes can be classified into two main types: resorbable membranes, made from materials such as collagen or polylactic acid, which gradually degrade and are absorbed by the body, eliminating the need for a second surgery but potentially offering limited mechanical stability and non-resorbable membranes, made from materials like expanded polytetrafluoroethylene (ePTFE), which provide excellent mechanical stability and space maintenance but require a second surgical procedure for removal, potentially increasing patient morbidity

Techniques and protocols for socket preservation include flapless extraction, which involves minimal soft tissue manipulation to preserve blood supply and reduce postoperative complications, often combined with immediate grafting to optimize outcomes.

The use of growth factors and biologics, such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), has been explored to enhance the regenerative potential of grafting materials, accelerating healing and improving the quality of regenerated bone . Additionally, emerging research on stem cell therapy, particularly with mesenchymal stem cells (MSCs), shows promising results in socket preservation as these cells can differentiate into osteoblasts and contribute to bone regeneration .

The cost-effectiveness and accessibility of socket preservation techniques are important considerations for clinical practice. While autografts and allografts are effective, they can be expensive and may not be readily available in all settings. Alloplasts and xenografts offer more cost-effective alternatives, and ongoing research aims to optimize their performance and reduce costs .

Chitosan gel, a natural biopolymer derived from chitin, has gained attention in tissue engineering and regenerative medicine due to its biocompatibility, biodegradability, and antimicrobial properties. Muzzarelli et al demonstrated that Chitosan gel-based scaffolds could support the regeneration of cartilage and bone, highlighting its potential in regenerative applications. Additionally, Chitosan gel's ability to form hydrogels and its hemostatic properties make it particularly suitable for dental applications.

Despite the promising properties of Chitosan gel, there is limited clinical evidence comparing its effectiveness to natural socket healing in the context of alveolar ridge preservation. A few studies have explored the use of Chitosan gel in dental applications, but comprehensive clinical trials are lacking. For instance, Park investigated the use of Chitosan gel membranes for guided bone regeneration and found favorable outcomes in terms of bone formation and biocompatibility.

Another study by Kim et al evaluated the use of Chitosan gel-collagen membranes in periodontal regeneration and reported enhanced bone and soft tissue healing.

Histomorphometric analysis is a critical tool for evaluating the quality and quantity of new bone and soft tissue formation at a microscopic level. This method provides detailed insights into the regenerative process, allowing for a comprehensive assessment of different socket preservation materials .

The findings from this trial could have significant clinical implications. Enhanced preservation of the alveolar ridge could reduce the need for additional grafting procedures, facilitate easier and more predictable implant placement, and ultimately improve patient outcomes Therefore, this study aims to provide high-quality scientific evidence on the efficacy of Chitosan gel in socket preservation, contributing to the existing body of knowledge and guiding future clinical practices. Moreover, the use of Chitosan gel could offer a cost-effective and readily available alternative to other grafting materials, potentially broadening the scope of socket preservation techniques

Inclusion Criteria:

• Patient having at least one hopeless tooth in posterior maxillary and mandibular area
• 18 years old or older.
• Motivated patients agree to sign the written informed consent and complete the follow up period
• Medically fit patients.
• No acute infections, pus formation, socket and bony discharges.
• Compliant the patient to ensure the follow up

Exclusion Criteria:

• Heavy smokers (more than 10 cigarettes per day or an electronic cigarette dose of >6 mg/ml of nicotine).
• Pregnant females.
• Presence of active infection or severe inflammation in the intervention zone.
• Relevant medical history that contraindicates implant surgery.
• Immunosuppression (eg. Hiv, solid-organ transplants).
• Head and neck-irradiated patients in the past 5 years.
• Regular intake of bisphosphonates, anticoagulants, or anti-inflammatories.
• Chronic drug abuse or alcoholic habits.
• Patients with poor oral hygiene (full-mouth plaque score and full-mouth bleeding score >15%) and lack of motivation.
• Uncontrolled diabetes (reported levels of glycated haemoglobin exceeding 7%).
• Active periodontal disease.
• Patients with significant comorbidity such as recent heart attack or coagulation disorder.
• Patients with a history of allergies.
• Mentally and physically handicapped patients.