Labial Bone Thickness Change in Immediate Implant Placement In Maxillary Esthetic Zone

Tooth replacement with dental implants in the esthetic zone is often accompanied with esthetic complications such as mid-facial gingival recession, implant thread exposure and a concave contour. Various methods have been introduced to minimize the occurrence of such complications, including applying connective tissue grafts, grafting the jumping gap, performing immediate temporization and using surgical guides to ensure the placement of the implant in the optimal prosthetic position.(El Ebiary et al., 2023)

It would be beneficial to establish an evidence-based protocol for the jumping gap distance to follow through, with all immediate implants in the aesthetic zone, most of which have thin labial bone to begin with. Though there have been multiple studies conducted, specifically in the past few years, there is insufficient evidence that tells us what the optimal jumping gap is. (Hamilton et al., 2023) (Lambert et al., 2023).

Therefore, the aim of our study is to evaluate this survival rate and the amount of change in labial bone thickness that will result in different horizontal defect dimensions (HDD) ≤ 2 mm in comparison to the \> 2 mm HDD.

The study will be conducted at the department of periodontology at the faculty of dentistry, Cairo University, Egypt. Patients will be selected from the outpatient clinic at the faculty of dentistry, Cairo University, Egypt. Patients screening will be carried out until the target sample is achieved.

Pre-operative phase:

Clinical evaluation:

1. An assessment of the patients' medical history and overall oral health will be conducted to ensure that it meets the study's eligibility requirements for participation. 2. Screening will then be done using periapical radiographs. 3. After patients are found eligible for enrolment, a Cone Beam Computed Tomography (CBCT) image will be taken to record the pre-operative bone level for the patient. 4. Following an in-depth description of the study's purpose and steps, the enrolled patients will have the opportunity to discuss with the researcher the informed consent. 5. The patients will sign a written informed consent form that has been translated into Arabic after they give their approval for the intervention and to follow the study process. 6. Impressions/digital scans will be taken for the patient in addition to the CBCT scan. A surgical guide will be fabricated and 3D-printed using model resin.

Radiographic examination:

A preoperative CBCT will be performed for patients who met the inclusion criteria to ensure their eligibility prior to surgery. (Joshi and Gupta, 2015)

Patient Preparation:

1. A full mouth supra and subgingival debridement (if needed) will be carried out for all recruited patients prior to surgery. Patients will be given oral hygiene instructions including brushing their teeth at least twice daily, in addition to rinse twice daily with 0.12% chlorohexidine mouthwash for two weeks. 2. Surgical treatment will not be scheduled until the patient demonstrates adequate plaque control (i.e., FMPS \< 20% and FMBS ≤ 10%). 3. Patients will be prescribed pre-surgical prophylactic antibiotic (2 g of amoxicillin 1 h before surgery or Clindamycin 600 mg in case of allergy to penicillin). Additionally, the patient will be asked to rinse with chlorhexidine 0.2% mouth wash for 1 min at the start of the surgery. (Salgado-Peralvo et al., 2022)

Surgical phase:

1. Following the administration of local anesthesia, atraumatic extraction of the remaining root will be done using a 15C lancet and a periotome to sever the periodontal ligament then using forceps with rotatory motion to pull out the root(s). The integrity of remaining labial bone wall (≥ 1mm) will be checked prior to the drilling sequence of the implant placement. 2. In case of multiple roots; separation using a carbide surgical bur mounted on a high-speed handpiece will be carried out. 3. Debridement of any granulation tissue will be carried out thoroughly using a bone curette and the area will be flushed with saline. 4. A fully guided flapless implant placement protocol will then be followed according to the pre-planned dimensions in C.B.C.T. 5. Implants with internal conical connection will be placed at least 4 mm away from the gingival margin to be able to establish a decent emergence profile later on in the prosthetic phase. 6. Primary stability will be checked to be able to take the decision for placing a customized healing abutments attached to the implant in place. (ISQ ≥ 65) 7. Bone substitute biomaterial will be grafted in the horizontal defect distance 'jumping gap' created between the external surface of the implant and inner wall of the socket. 8. Customized healing collars will be inserted finally on the implants to cover the socket and stabilize the wound and graft material beneath.

Post-operative instructions:

1. Patients will continue to receive postoperative antibiotics for five days after surgery (Salgado-Peralvo et al., 2022) 2. Patients were instructed to follow oral hygiene measures and to use chlorhexidine 0.2% mouthwash for 2 weeks. 3. All patients will be clinically evaluated at 1 week and 2 weeks to make sure that the initial healing phase is going without complications.

Follow-up:

Each patient will be evaluated at 3, 6, 9 and 12 months post-operatively.

• Jumping gap (accuracy) [Срок оценки: Before implant placement and immediately after.]
• Crestal Bone Level [Срок оценки: Assessment at baseline, 3 months, 6 months, 9 months and 12 months.]
• Pink Esthetic Score [Срок оценки: Assessment after final crown delivery (baseline), 3 months, 6 months, 9 months and 12 months.]
• Patient satisfaction [Срок оценки: One time at 12 months after crown delivery.]
• Keratinized soft tissue width [Срок оценки: Assessment will be at the surgery day (baseline), 3 months, 6 months, 9 months and 12 months after crown delivery.]
• Keratinized soft tissue thickness [Срок оценки: Assessment will be at the surgery day (baseline), 3 months, 6 months, 9 months and 12 months after crown delivery.]