Evaluation the Depth of Cure of Bulk Fill Resin Composites by Microhardness

Creative Commons License

Araz E., Üçtaşlı M. B.

2026 CED/NOF-IADR Oral Health Research Congress , Lisbon, Portekiz, 3 - 05 Eylül 2026, sa.318, ss.329, (Özet Bildiri)

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Lisbon
  • Basıldığı Ülke: Portekiz
  • Sayfa Sayıları: ss.329
  • Gazi Üniversitesi Adresli: Evet

Özet

Evaluation the Depth of Cure of Bulk Fill Resin Composites by Microhardness

Emre Araz, Mine Betül Uctasli

restorative dentistry, Gazi university, Ankara, Ankara, Turkey

Objectives The aim of this study was to evaluate the depth of cure of five different bulk-fill and a universal composite resin using Vickers Microhardness. Methods A total of 30 samples were prepared, 5 for each bulk-fill composite resin (3M Filtek One(3M ESPE USA),FGM Opus Bulk Fill(Brasil), Tetric N Ceram Bulk Fill (Ivoclar Vivadent,Liechtenstein), GC Everx Posterior Bulk Fill(Kyoto JAPAN),Aura Bulk-fill (SDI, Australia), using a standart 2×2×6 mm rectangular shape mold. Resin composite materials were placed into the mold by bulking technique and polymerized with a LED light curing unit (D Light Pro, GC, Japan) at high power mode (1400mw/cm2) for 20 seconds. Samples were stored in 370 C degree for 24 hours. To assess the depth of cure of bulk-fill resin composites and a universal composite resin, a micro-hardness testing machine (Shimadzu,Japan) was used to measure Vickers Hardness Number (VHN) of resin composites under 100 g indentor load and 15 s dwell time.Measurements of each sample were performed at interval depths of 1 mm, starting at 0.5 mm, 1 mm, 2mm, 3mm, 4mm, and 5 mm. Three measurements were obtained at each depth, 0.5 mm apart from each indentation, and the micro-hardness number was determined by taking the average of three VHN. Results The data were statistically analyzed using two way ANOVA and Post Hoc tests. All materials showed a decrease in the VHN starting from the 1mm, but the significant decrease started at 4mm depth (p<0.05). Filtek Ultimate (control group) showed the highest VHN at 0.5 mm, and Aura bulk-fill composite resin showed the lowest VHN at 0.5 mm. All five bulk-fill composite resin materials met the acceptable threshold of 80% degree of conversion at 4 mm, indicating adequate polymerization. The Filtek Ultimate composite resin material (control group) showed 80% acceptable degree of conversion at 2 mm. Conclusions All bulk-fill composite resin materials achieved acceptable polymerization at certain depths; however, microhardness significantly decreased from 0.5mm (upper) to 5mm (bottom). While most materials met the ≥80% conversion threshold at 4 mm depth, variations among materials were observed, with Filtek Ultimate showing superior performance. These findings suggest that curing efficiency remains material dependent, particularly at greater depths.