This randomized controlled clinical trial evaluates the effect of different resin composite preheating protocols on pulpal inflammation and postoperative pain. Thirty patients with deep occlusal carious lesions (ICDAS scores 5 and 6) will be randomly assigned to three equal groups (n=10). Group I will receive thermoviscous bulk-fill composite (VisCalor, VOCO) preheated to 65°C and placed as a single 4-mm increment. Group II will receive conventional nanohybrid composite (Ivoclar Vivadent) preheated to 55°C and placed incrementally. Group III (control) will receive the same composite at room temperature (23°C) using incremental placement. Gingival crevicular fluid (GCF) samples will be collected at baseline, immediately post-treatment, and at 7-day follow-up. Tumor necrosis factor-alpha (TNF-α) concentrations will be quantified using ELISA. Postoperative pain will be assessed using the Visual Analog Scale (VAS) at baseline and day 7. The study aims to determine whether different preheating protocols differentially affect pulpal inflammatory status and whether GCF TNF-α correlates with postoperative pain.
Inclusion Criteria:
Patients aged 18-45 years in good general health
Asymptomatic deep occlusal carious lesions with ICDAS scores 5 and 6, confirmed by preoperative periapical radiographs
Healthy gingiva with probing depths ≤ 3 mm
Normal occlusion
No radiographic evidence of periodontal bone loss
No anti-inflammatory or antibiotic therapy within the preceding six months
Willingness to provide written informed consent and complete the full study period
Exclusion Criteria:
Pregnant or nursing women
Incarcerated individuals
Individuals with mental health disorders
Current tobacco users
Patients with systemic conditions (e.g., diabetes mellitus, immunocompromise)
Teeth with prior endodontic therapy
Periodontal pockets >3 mm
Use of medications influencing inflammatory responses
Orthodontic appliance wearers
History of allergy to dental materials or local anesthetics
Active periodontal disease
Teeth with periapical pathology or pulp exposure
In this single-blinded study, the outcome assessor is masked to group allocation. The assessor responsible for GCF sample collection, ELISA analysis, and pain score evaluation has no knowledge of which intervention each participant received. The operator who performs the restorative procedures cannot be masked due to the nature of the preheating protocols (different devices and temperatures). Participants are not informed of their group assignment to minimize expectation bias. The allocation sequence is concealed in sequentially numbered, sealed, opaque envelopes, and the assessor does not have access to the randomization list.
Participants in this arm will receive deep Class I restorations using thermoviscous bulk-fill composite (VisCalor, VOCO, Germany) preheated to 65°C using the VisCalor Dispenser. The composite is placed as a single 4-mm bulk increment and light-cured according to the manufacturer's instructions. GCF samples are collected at baseline, immediately post-treatment, and at 7-day follow-up for TNF-α quantification. Pain is assessed using VAS at baseline and day 7.
Participants in this arm will receive deep Class I restorations using conventional nanohybrid composite (Tetric EvoCeram, Ivoclar Vivadent, Liechtenstein) preheated to 55°C using a Composite Heater (Cicada Dental, China). The composite is placed incrementally in 2-mm layers and light-cured according to the manufacturer's instructions. GCF samples are collected at baseline, immediately post-treatment, and at 7-day follow-up for TNF-α quantification. Pain is assessed using VAS at baseline and day 7.
Participants in this arm will receive deep Class I restorations using conventional nanohybrid composite (Tetric EvoCeram, Ivoclar Vivadent, Liechtenstein) at room temperature (23°C) with no preheating. The composite is placed incrementally in 2-mm layers and light-cured according to the manufacturer's instructions. This arm serves as the control group. GCF samples are collected at baseline, immediately post-treatment, and at 7-day follow-up for TNF-α quantification. Pain is assessed using VAS at baseline and day 7.
Cairo, Cairo Governorate, Egypt
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