Preheating resin composites is the warming of resin composites by using a heating device (composite warmer) before its placement. Preheating increases the flow properties and allows better adaptation to cavity preparation. The high thermal energy also improves polymerization rate, thereby reducing microleakage. Conventional composites resin is used as one-paste light-cured systems, which are built up in increments to overcome the effects of setting shrinkage and to ensure thorough curing.

Several studies report failure of cervical restorations of noncarious cervical lesions and an incessant search for the most suitable restorative material. Therefore, this study aims to evaluate the clinical performance of conventional resin composites compared with preheated resin composites in the treatment of noncarious cervical lesions. Our null hypothesis states that there is no difference between the clinical performance of preheated resin composites and conventional resin composites in the treatment of noncarious cervical lesions.

This study will be conducted at the Conservative and Endodontics Department in Polyclinic B, Faculty of Dentistry, Manipal University College Malaysia (MUCM). It involves forty-six randomly selected patients with two similar noncarious cervical lesions, each on a canine, first premolar, second premolar or first molar on the contralateral side of the maxillary arch. One lesion will be restored with preheated resin composite (3M™ Filtek™ Z350 XT Universal Restorative) while the other lesion will be restored with conventional resin composite (3M™ Filtek™ Z350 XT Universal Restorative). Both restorations will be done on each patient's first visit. The patients will be recalled 1,3 and 6 months later for assessment of the restorations, using modified US Public Health Service (USPHS) criteria: marginal integrity, marginal discoloration, wear, retention, secondary caries and postoperative sensitivity.

Inclusion Criteria:

• Patients who are systemically healthy (ASA I and ASA II )44 and have satisfactory oral hygiene (OHI-S score of 0 to 3.0).
• Participants must have two noncarious cervical lesions (abrasion/abfraction), each on a canine, 1st premolar, 2nd premolar or 1st molar on the contralateral side of same dental arch (maxillary arch) with similar depth and width.
• Both NCCLs are in contact with antagonist teeth as well.

Exclusion Criteria:

• Participants requiring dental prostheses of the target teeth.
• Participants have a diagnosis of caries coincident with the cervical lesion, or an indication for irreversible endodontic treatment of the target teeth.
• Existence of periodontal damage with respect to the target teeth.