engleski

Depth of cure of experimental bioactive composites by ISO 4049 – a comparison with raman spectroscopy

Aim: To investigate the curing efficiency of experimental composites containing bioactive glass fillers by the ISO 4049 method and to compare the results with the degree of conversion (DC) measured by Raman spectroscopy. Materials and methods: Experimental light-curable composites based on Bis-GMA/ TEGDMA resin were denoted as BG-0, BG-5, BG-10, BG-20 and BG-40, where the numbers represent the wt% of the bioactive glass 45S5. A standard ISO 4049 depth of cure (DoC) scraping test was performed on specimens (n=6) cured for 10, 20 or 30 s with 1070 mW/cm2. Immediately after light-curing, the uncured material was removed and the remaining cylinder length divided by two was reported as the DoC. DC was measured by Raman spectroscopy at various depths (0, 1, 2, 3, and 4 mm) of specimens of the same geometry. A commercial composite Tetric EvoCeram (TEC) was used as a reference. Results: ISO 4049 DoC (mm) for the curing times of 10s/20s/30s were as follows: BG- 0: 2.8/3.1/3.2, BG-5: 2.3/2.8/3.1, BG-10: 2.2/2.7/3.0, BG-20: 1.9/2.4/2.5, BG-40: 2.0/2.5/2.6, TEC: 2.1/2.4/2.5. Partial eta-squared statistics showed a highly significant influence of curing time and material, as well as their interaction, on the DoC. DC values showed a steeper decline with the increasing amount of bioactive glass, which is in line with the DoC values ranking: BG-0>BG-5>BG-10>BG-20>BG-40. Conclusion: All the experimental composites showed DoC values similar or higher than the commercial reference. Most of the materials attained the stipulated DoC of 2 mm with the curing time of 10 s.

depth of cure, ISO 4049, vibrational spectroscopy

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