The clinical performance of a bioactive composite (alkasite-based), a nanohybrid resin composite and a bulk-fill resin composite in class II restorations will be evaluated and compared. After recruiting participants with at least 3 approximal caries lesions, all restorations will be placed by a single clinician. All caries lesions will be removed before restoring. Cavities will be divided into three groups: a bioactive composite [Cention Forte Ivoclar Vivadent, Schaan, Liechtenstein], a nanohybrid resin composite [Tetric N-Ceram2 (Ivoclar Vivadent, Schaan, Liechtenstein)] and a bulk-fill resin composite [Tetric N-PowerFill2 (Ivoclar Vivadent, Schaan, Liechtenstein)], All restorative procedures will be conducted according to manufacturers' instructions. Restorations will be scored using FDI criteria after a week (baseline) 6, 12, 24, 36 and 48 months. Descriptive statistics will be performed using chi-square tests.

Inclusion Criteria:

• age range will be 18 to 65
• patients should have at least 3 approximal caries lesions require restoration
• healthy periodontal status
• a good likelihood of recall availability

Exclusion Criteria:

• poor gingival health
• adverse medical history
• potential behavioral problems