The aim of this study is to evaluate the effect of flowable conventional and bulk-fill composites on postoperative sensitivity in class I cavities over long-term follow-up. The hypothesis to be tested in this study is that the type of composite material will not affect clinical success.

Inclusion Criteria:

• good general health
• no heart disease
• no diabetes
• no systemic diseases such as hypertension

Exclusion Criteria:

• Patients with advanced periodontitis and associated postoperative sensitivity,
• Pregnant and breastfeeding women,
• Patients undergoing orthodontic treatment,
• Patients using appliances,
• Patients with direct pulp capping

The entire study will be conducted at the Restorative Dentistry Department clinic of the Faculty of Dentistry at Recep Tayyip Erdoğan University. Participants who have received routine dental treatment at the university's dental clinic and whose records are kept will be included in the research.