Background: This 3-year clinical trial compared the performance and post-operative sensitivity of a posterior resin composite with that of bonded-amalgam in large sized cavities. Additionally, it was evaluated whether resin composite could be an alternative for bonded amalgam.

Methods: This was a randomized clinical trial. Patients in need of at least two posterior restorations were recruited. Authors randomly assigned one half of the restorations to receive bonded-amalgam and the other half to composite restorations. Forty bonded-amalgams and composites were evaluated for their performance on modified Ryge criteria and post-operative sensitivity using VAS for 36-months.

Inclusion Criteria:

To be included, the teeth to be restored had to:

1. be asymptomatic
2. have occlusal and adjacent teeth in contact
3. have cavity sizes exceeding the one-third of the bucco-lingual distance between cusp tips -

Exclusion Criteria:

• Patients with periodontitis, poor oral hygiene, bruxism or a history of allergic reactions to any of the materials