The aim of this clinical study is to investigate the impact of the deep margin elevation technique on the clinical performance of CAD/CAM endocrown restorations in deep Class II cavities.

This study aims to evaluate the impact of the deep margin elevation technique on the clinical performance of endocrown restorations made from nano-ceramic blocks produced using the CAD/CAM system for class II cavities with deep margins. Factors such as color harmony with adjacent teeth and restorations, discoloration, anatomical form continuity, adaptation, secondary caries, and retention will be examined in the nano-ceramic block material.

Various treatment options are available for the restoration of posterior group teeth. Factors such as restoration material, condition of supporting tooth tissue, patient habits, and clinical protocols affect the lifespan of restorations. Advances in tooth preparations ensure the preservation of sound tooth structure and the longevity of restorations.

The CAD/CAM system is a technology used in dentistry, consisting of three essential elements: data acquisition, design, and production. With this system, dentists can design and produce restorations such as veneers, crowns, and bridges using digital modeling and manufacturing methods.

The restoration of endodontically treated teeth may require different approaches than post-core and crown restorations that can affect mechanical resistance. The development of adhesive techniques and the importance of minimally invasive dentistry have led to new therapeutic approaches, such as monolithic endocrown restorations fixed to the pulp chamber and cavity margins.

Dental adhesion is the attractive force between the tooth surface and the applied material, and dentin bonding systems have been developed to ensure adhesion between the two structures. These systems enhance adhesion by increasing dentin surface energy and facilitating the spread of adhesive resin into the dentin.

Procedures such as isolation, measurement, cementation, and residual cement cleaning can be challenging in cases with deep margins. Clinical strategies can assist in overcoming isolation difficulties in subgingival margin areas where adhesive procedures are applied.

The restoration of teeth with advanced substance loss can be a challenging process for operators, and the selection of the correct treatment plan is crucial. This clinical research aims to examine the impact of the deep marginal elevation technique on the clinical performance of CAD/CAM-produced endocrown restorations.

Inclusion Criteria:

• Healthy individuals without any uncontrolled systemic diseases.
• Individuals aged between 18 and 65 years.
• Individuals who pay attention to oral hygiene by brushing their teeth twice a day.
• Patients with at least one canal-treated posterior tooth, multiple cusp loss, and at least one tooth wall loss identified during intraoral examination.
• Patients who have successfully completed periodontal and endodontic treatments and do not exhibit any subjective symptoms.

Voluntary individuals who agree to participate in the study and sign the informed consent form will be included in the research.

Exclusion Criteria:

• Individuals with uncontrolled systemic diseases.
• Individuals with mental retardation who cannot establish cooperation.
• Individuals with advanced periodontal disease.
• Individuals using removable partial dentures.
• Individuals with bruxism.
• Individuals with malocclusion.
• Patients with advanced substance loss requiring extraction of the relevant tooth, and individuals with deep margins requiring periodontal interventions.

Individuals who, after being informed about the study, choose not to read the informed consent form and decline to participate in the study.