In-vitro investigation of the holding capacities of volatile sulfur compounds of different restorative materials

Objective: The aim of this study is to investigate the amount of volatile sulfur compounds, especially hydrogen sulfide, released from different restorative materials kept in Alluim cepa. Method: Our study was carried out in two stages. In both stages, the samples were placed directly in Alluim cepa (Onion) and left for 1 min. Measurements were made immediately after the surface was cleaned. In the first stage of our thesis, which is a preliminary study, the holding capacity of volatile sulfur compounds of some representative selected restorative materials were investigated by using a sulfur monitor (Halimeter). In the second stage of our thesis, the amounts of H2S gas released from thirteen different restorative materials were compared using a hydrogen sulfide (H2S) detector. Amalgam (Nova 70-Caps), glass ionomer (Equa Forte HT), universal composite (Tetric EvoCeram), bulk fill composite (Tetric EvoCeram Bulk Fill), flowable composite (G-ænial Universal Injectable), ormoser (Admira Fusion x-tra) and zirconia (Vita YZ HT) based filling materials formed representative groups (n=10 total 70) in sulfur monitor tests. In the detection of H2S gas, the holding capacity of H2S gas was examined with a detector (Wintact WT8802). The sample groups (n=10) made from one high copper amalgam (Nova 70-Caps), two different glass-ionomer based filling materials (Fuji IX GP, Equa Forte HT), four different composites, two of which are bulk fill , (Tetric EvoCeram Bulk Fill, IPS Empress Direct, Admira Fusion x-tra, Tetric EvoCeram) three different flowable composites, one of which contains fiber (everX Flow, G-ænial Universal Injectable, Tetric EvoFlow) and three different CAD-CAM blocks (Vita Enamic, GC Cerasmart 270, Vita YZ HT). All restorative material samples were prepared with a diameter of 5 mm and a thickness of 2 mm. In order to investigate the effect of sample thickness in bulk fill composites, 10 more samples with an additional 5 mm diameter and 4 mm thickness were prepared. Before the measurements, the samples were polished and kept in distilled water for 1 week. In addition, to investigate the effect of roughness, the surface of CAD-CAM samples was roughened with a fissure bur with a particle size of 181µm after the first measurements, and the effect of roughness was investigated by making additional measurements. Results were analyzed with Kruskal Wallis test and Bonferroni corrected pairwise comparison tests. The effect of roughening on CAD-CAM samples was made with the Wilcoxon test, and the comparison of 4 mm thick bulk fill composites was made with the Mann Whitney U test. Results: As a result of the preliminary study with the sulfur monitor, it was found that there were differences between the groups (p>0.05) and observed that the use of Equia Coat glass ionomer varnish affected the results. In the measurements made with the H2S monitor, it was detected that the H2S release was dependent on the material type. The lowest median peak values were detected in the samples obtained from CAD-CAM blocks (0 mmol), while the highest median values were detected in the 4 mm Tetric EvoCeram Bulk Fill samples (1.3 mmol). The roughening of CAD-CAM materials did not increase the amount of H2S released. Conclusions: After the restorative materials are stored directly in Alluim cepa, the amounts of H2S released from the samples and the release periods vary depending on the materials. Solvents contained in Equia Coat glass ionomer varnish can affect the measurement results of the Halimeter instrument which is a sulfur monitor. Keywords: Restorative material, Volatile sulfur compounds, Halitometer, H2S detector, Halitosis