This is a double blinded, split mouth, randomized clinical study that evaluated the performance of a glass hybrid restorative material in class III lesions. The lesions will be restored with glass hybrid restorative (Equia Forte) or anterior composite resin (G-aenial Anterior). Restorations will be evaluated after 24 months according to FDI criteria and the data will be analyzed.

The aim of this study was to comparatively evaluate the clinical performance of a glass-hybrid-restorative with an anterior composite resin (G-aenial Anterior) in class III lesions.

Participants who are 18 years of age or older and healthy, and who have applied to the Restorative Dentistry Department of Hacettepe University Faculty of Dentistry to receive treatment for class III lesions on their front teeth will be included in the study. After explaining the purpose and conditions of the study, they will be asked to sign an informed consent form. The gender, age, and tooth numbers of the participants to be treated will be recorded. 100 upper incisors of 50 patients will be treated, with attention paid to the balanced distribution of teeth in the right and left arches. The "split-mouth" model will be used in the study, with two teeth included in one mouth and each restorative material placed in one tooth. The restorative material to be placed on the teeth will be determined randomly. Before starting the restoration, papers with the names of both materials will be placed in envelopes, and then the assistant staff will be asked to randomly select one of the envelopes during the restoration stage to provide randomization.Data were will be analyzed with Chi- Square, Fisher's Exact Test, Mann U tests

Inclusion Criteria:

• The participant must be at least 18 years of age or older
• The participant has at least two class III lesions and the lesions are in symmetrical teeth located in the right and left arch
• The lesion covers at most 2/3 and at least 1/3 of the dentin
• Participant voluntarily signing the informed consent form
• The participant does not have a physical disability that may prevent them from coming to the control.
• Absence of a periapical pathology in the involved tooth

Exclusion Criteria:

• Having systemic disorders that may prevent the participant from regularly attending treatment and control appointments.
• Having severe periodontal problems in the tooth planned to be treated
• Absence of the opposite of the tooth and not participating in chewing
• Lesions which is limited with the enamel tissue
• Teeth with lesions that are too large to be restored
• Patients with anterior malocclusion
• Patients with parafunctional habits.
• Mentally disabled patients.