This study aimed to investigate the effect of using a loupe and dental operating microscope with different magnifications on the success of class II direct composite restorations.

A total of 130 class II, D2 deep caries teeth of 85 patients were randomly distributed to the naked eye, 3x magnification loupe, 5x magnification loupe, 8.5x magnification dental operating microscope (DOM) groups, and direct composite restorations were made with these magnification aids. carried out. Clearfil SE Bond 2 and Clearfil Majesty Posterior composite were used in all restorations. The restorations were evaluated using FDI criteria at 1,6 and 12-month periods, and restorations were scored between 1 and 5 for all criteria.

Inclusion Criteria:

• Good oral and dental care of the patient,
• The need for at least 1 Class II restoration at a depth of D2 in the posterior group teeth,
• No crowding in the tooth to be restored, tooth contact and antagonist,
• The relevant tooth is vital,
• Absence of pain on percussion and palpation of the tooth.
• Absence of any pathology in the periapical tissues in radiographic evaluation,
• The patient was informed about the study and accepted the study,
• Having agreed to attend 1 month, 6 month and 12 month control sessions,
• The patient has no systemic disease,

Exclusion Criteria:

• Presence of severe periodontal disease,
• Teeth that cannot be insulated, malposed or overloaded or not loaded at all,
• Periodontal and endodontic removal of the relevant tooth is healthy,
• the patient is undergoing orthodontic treatment,
• Recording of dry mouth is set,
• Severe bruxism habit,
• Smoking