Comparative evaluation of clinical performance of bulk-fill composites with incrementally layered conventional composites

This study aimed to compare the clinical effectiveness of bulk-fill composites with conventionally layered incremental composites in Class I cavities using modified USPHS criteria. Patients aged 15 to 50 years of either gender visiting Fatima Jinnah Dental College and Hospital OPD who fulfilled the inclusion criteria (vital first and second molar teeth with Class I cavities having a depth of 3-4 mm) were recruited in the study from July 2021 to January 2023. Fifty patients were selected based on sample size calculations. Each patient received two restorations, one from each group. Group A received incremental layering composite restorations, while Group B received bulk-fill composite restorations. Group A restorations were placed on the right side, and Group B restorations were placed on the left side. A single trained operator placed all restorations. After one year, the restorations were evaluated using modified USPHS criteria. Periapical radiographs were taken, and postoperative sensitivity was assessed using cold testing (ethyl chloride spray), with pain responses recorded using the Visual Analogue Scale. Descriptive statistics and post-stratification Chi-square tests were performed. Group A showed 100% absence of postoperative sensitivity compared to 94% in Group B. Satisfactory clinical performance was observed in 96% of Group A restorations and 92% of Group B restorations. There was no statistically significant difference in satisfactory clinical performance between the two techniques. Bulk-fill composite resin placement demonstrated comparable clinical performance to incrementally placed composite restorations after one year of follow-up in Class I permanent molar teeth restorations.Trial registration ClinicalTrials.gov NCT07078110 (registered retrospectively on 22-07-2025).