The aim of this study is to compare the clinical success of different filling materials used in the treatment of dental caries. Systemically healthy individuals with good oral hygiene and interproximal caries in their posterior teeth participated in the study. Participants underwent initial radiographic and intraoral examinations. Three different filling materials were applied to the participants' teeth. The restorations were evaluated at baseline, 1 year, and 2 years.

The aim of this study was to evaluate the clinical performance of Class II carious defects restored with traditional posterior composite, bulk-fill composite, and high-fill flowable composite resin according to the World Dental Federation (FDI) criteria at 12-month and 24-month intervals. In this study, 110 patients underwent initial radiographic and intraoral examinations. Radiographically, 259 teeth with interproximal caries at D1 and D2 levels were identified. All restorations in the study were performed by the same dentist. Before starting the restoration procedure, local anesthesia was administered to the tooth or teeth. The caries were removed and the preparation was completed. Following the washing and drying of the cavities, cotton rolls and saliva ejectors were placed to ensure isolation. An appropriate matrix system and wooden wedges were applied. A 0.2% chlorhexidine gluconate solution was used as the cavity disinfectant. Subsequently, the enamel surfaces of the teeth were roughened for 30 seconds using a selective etching technique with 37% phosphoric acid. The universal dental adhesive system was applied according to the manufacturer's instructions..The first group received bulk-fill composite resin (Filtek One Bulk Fill Restorative), the second group received traditional posterior composite (Clearfil Majesty Posterior ), and the third group received high-filler flowable composite resin. The same universal dental adhesive system was used for all groups. All restorations were evaluated by two experienced dentists according to the FDI evaluation criteria at baseline,1 year and 2 years. In cases where discrepancies were observed between the two examiners, the assessment was based on a consensus decision made by both dentists. Restorations were evaluated and scored separately for each criterion on a scale from 1 to 5: 1 = clinically excellent, 2 = clinically good, 3 = clinically adequate, 4 = clinically insufficient (requires repair), 5 = clinically poor (requires replacement).

Inclusion Criteria:

• The patient has no systemic disease
• The patient should be over 18 years of age
• The patient should have good periodontal status
• Teeth to be restored should be symptomless and vital
• Teeth to be restored should have proximal contacts on both mesial and distal surfaces and be in occlusion with the antagonist teeth
• Teeth that have class II caries lesion in external and middle 1/3 of dentine thickness radiographically

Exclusion Criteria:

• Xerostomia and bruxism
• Absence of adjacent and antagonist teeth
• Extremely poor oral hygiene, severe or chronic periodontitis
• Pregnant or lactating women
• Teeth that have any restoration, endodontic treatment, periodontal and periapical pathology.
• The patients who are undergoing orthodontic treatment

While the materials used for the restorations were known to the practitioner, neither the patients nor the specialist dentists conducting the follow-up examinations were aware of them.