Testing of optimal polymerization protocols for fast polymerizing bulk fill composite materials

Svrha ovog istraživanja bila je ispitati utjecaj polimerizacije uređajem vrlo visokog intenziteta zračenja pri kratkom razdoblju od 3 sekunde na polimerizaciju nove generacije bulk-fill kompozitnih materijala. Ispitana su četiri materijala: Filtek One Bulk Fill (3M, St. Paul, SAD), Tetric PowerFill (Ivoclar Vivadent, Schaan, Lihtenštajn), Tetric PowerFlow (Ivoclar Vivadent) te SDR (Dentsply, Konstantz, Njemačka). Materijali (n = 5) polimerizirani su standardnim (950 mW/cm2 ) ili 3 s protokolom osvjetljavanja (2652 mW/cm2 ; Bluephase PowerCure, Ivoclar Vivadent). Nakon izrade polimerizirani uzorci 29 dana bili su pohranjeni u mraku u fiziološkoj otopini na 37 °C te skladišteni u tamnom eksikatoru 3 dana. Stupanj konverzije izmjeren je pomoću Ramanovog spektrometra (Spectrum GX Perkin- Elmer, Waltham, MA, SAD) sa snagom lasera 850 mW i rezolucijom 4 cm-1 s 150 skenova/mjerenju. Srednje vrijednosti statistički su uspoređene uporabom jednosmjerne ANOVA-e s Tukeyjevim prilagođavanjem za više usporedbi, na ukupnoj razini značajnosti od 0,05. Visok stupanj konverzije pokazali su svi ispitani materijali polimerizirani standardnim protokolom osvjetljavanja, kao i 3 s polimerizacijom. Nije bilo razlike u stupnju konverzije između različitih polimerizacijskih protokola za Tetric PowerFill i SDR Plus Bulk Fill Flowable. U skupini uzoraka polimeriziranih 3 s donji uzorci na dubini 2 − 4 mm bili su nešto slabije polimerizirani. Polimerizacija 3 s fotopolimerizacijskim uređajem vrlo visokog intenziteta ovisi o kemijskom sastavu kompozitnih materijala i potreban je oprez pri kliničkoj uporabi.The purpose of this study was to examine the effect of polymerization with a very high-intensity curing unit over a short period of 3 seconds on the polymerization of a new generation of bulkfill composite materials. Four materials were tested: Filtek One Bulk Fill (3M, St. Paul, USA), Tetric PowerFill (Ivoclar Vivadent, Schaan, Liechtenstein), Tetric PowerFlow (Ivoclar Vivadent), and SDR (Dentsply, Konstanz, Germany). Materials (n = 5) were polymerized with a standard (950 mW/cm2 ) or 3 s illumination protocol (2652 mW/cm2 ; Bluephase PowerCure, Ivoclar Vivadent). After preparation, the polymerized samples were stored in the dark in saline at 37°C for 29 days and stored in a dark desiccator for three days. The degree of conversion was measured using a Raman spectrometer (Spectrum GX Perkin-Elmer, Waltham, MA, USA). Mean values were statistically compared using a one-way ANOVA with Tukey’s adjustment for multiple comparisons, at an overall significance level of 0.05. A high degree of conversion was shown by all tested materials polymerized both by the standard illumination protocol, as well as with 3 s polymerization. There was no difference in conversion rate between the different polymerization protocols for Tetric PowerFill and SDR Plus Bulk Fill Flowable. In the group of samples polymerized 3 s, the lower samples at a depth of 2 - 4 mm were slightly less polymerized. Polymerization for 3 s with a high light intensity photopolymerization device depends on the chemical composition of resin composites and caution is advised in clinical application