The present study aims to evaluate a 2-years clinical performance of sonic-activated bulk-fill resin composite material (sonic fill) in comparison to conventional bulk-fill resin composite (X-tra fill) as posterior restorations. The null hypothesis is that sonic-activated bulk-fill resin composite restoration shows no difference when compared to conventional bulk-fill resin composite in clinical performance over 2-years evaluations based on clinical assessment.

Restorations will be evaluated 1 week after placement (Baseline - T0), 3 months (T1), 6 months (T2), 1-year (T3) and 2-years (T4) of clinical service by blinded calibrated examiner using modified United States Public Health Service (USPHS) criteria where score A (Alpha) stands for the clinically ideal restoration. Score B (Bravo) is a clinically acceptable situation except for secondary caries. Score C (Charlie) indicates clinically unacceptable restorations that must be replaced.

The restorations will also be evaluated using revised FDI criteria with five grades for each criterion; scores 1 to 3 indicated clinically acceptable restorations, and scores 4 and 5 summarized clinically unacceptable situations indicating repair (score 4) or replacement (score 5).

Inclusion Criteria:

• They should have an acceptable oral hygiene level.

  • Presence of at least two posterior carious lesions to be restored with two different types of composite.
  • The two materials should be used in approximately the same sized lesions or within the same extension.
  • Age range between 18 and 45 years.
  • A good likelihood of recall availability.

Exclusion Criteria:

• Severe or active periodontal or carious disease.
• Heavy bruxism or a traumatic occlusion.
• Patients with a compromised medical history or had received therapeutic irradiation to the head and neck region.
• Alcoholic and smoker patients.
• Patients had participated in a clinical trial within 6 months before commencement of this trial.
• Patients unable to return for recall appointment.