Introduction: Resin composite restorations are among the most commonly used materials for restoring posterior teeth due to their aesthetic and mechanical properties. Self-cured resin composites have emerged as a promising option to overcome some of the limitations of conventional light-cured composites.

Aim: The aim of this study is to evaluate the effect of self-cured resin composite in restoring occlusal cavities of posterior teeth over a period of two years. The results will contribute to clarifying its efficiency and safety as a treatment option in daily clinical practice.

Research Steps: Fifty affected teeth will be selected and randomly allocated into groups.

Group (A): Self-cured resin composite group - self-cured resin composite will be used.

Group (B): Bioactive nano-hybrid resin composite group - bioactive nano-hybrid resin composite will be used.

The restorations will be evaluated after placement.

Introduction:

Resin composite restorations are among the most widely used materials in restorative dentistry due to their favorable aesthetic and physical properties. However, the success of these restorations largely depends on the type of material used and the technique of application. Conventional light-cured composites are the most common option, yet they may present certain limitations in cases where adequate isolation is difficult to achieve or in posterior areas of the mouth.

In contrast, self-cured resin composites have emerged as a promising alternative because of their ability to polymerize chemically without the need for a light source. These materials are characterized by ease of use and the possibility of application under limited clinical conditions, making them suitable in certain clinical situations.

Aim of the Study:

The aim of this randomized controlled clinical trial is to evaluate the clinical performance of a newly introduced self-cured resin composite (Stela, SDI, Australia) in class I occlusal cavities of posterior teeth compared to light-cured Nano-hybrid bioactive resin composite (Beautifill II, Shofu, Japan) regarding functional properties over a follow-up of 2 years.

Research Question:

Does the clinical performance of self-cured resin composite restorations differ from light cured nano-hybrid bioactive resin composite in class I cavities?

Inclusion Criteria:

• Adult patients typically between 18 to 50 years old.
• Males or Females.
• Co-operative patients approving the trial.
• Good oral hygiene.

Exclusion Criteria:

• Lack of compliance.
• Patients with bad oral hygiene.
• Patients who are allergic to any ingredients used in the study.
• Medically compromised patients with systemic complications that would alter the treatment.
• Inability to give informed consent.