Tugrul Sari

Antimicrobial efficiency of photodynamic therapy with different irradiation durations

Objective: This study aimed to evaluate the antimicrobial efficiency of PDT and the effect of different irradiation durations on the antimicrobial efficiency of PDT. Materials and Methods: Sixty freshly extracted human teeth with a single root were decoronated and distributed into five groups. The control group received no treatment. Group 1 was treated with a 5% sodium hypochlorite (NaOCl) solution. Groups 2, 3, and 4 were treated with methylene-blue photosensitizer and 660-nm diode laser irradiation for 1, 2, and 4 min, respectively. The root canals were instrumented and irrigated with NaOCl, ethylenediamine-tetraacetic acid, and a saline solution, followed by autoclaving. All the roots were inoculated with an Enterococcus faecalis suspension and brain heart infusion broth and stored for 21 days to allow biofilm formation. Microbiological data on microorganism load were collected before and after the disinfection procedures and analyzed with the Wilcoxon ranged test, the Kruskal-Wallis test, and the Dunn′s test. Results: The microorganism load in the control group increased. The lowest reduction in the microorganism load was observed in the 1-min irradiation group (Group 2 = 99.8%), which was very close to the results of the other experimental groups (99.9%). There were no significant differences among the groups. Conclusions: PDT is as effective as conventional 5% NaOCl irrigation with regard to antimicrobial efficiency against Enterococcus faecalis.

The effect of coloring liquids on the translucency of zirconia framework

PURPOSE Translucency of all-ceramic restorations is an important factor which affects the final appearance and esthetic outcome of the restoration. The aim of this study was to evaluate the effect of the shade of coloring liquid on the translucency of zirconia framework. MATERIALS AND METHODS Thirty zirconium oxide core plate (15 × 12 × 0.5 mm) were divided into 6 groups of 5 plates each. Each group was classified according to the shade of coloring liquid based on Vita Classic Scale (A2, A3, B1, C2, and D2), and each sample was immersed in coloring liquid for 3 seconds as recommended by the manufacturer, except for the control group. Contrast ratio, as a translucency parameter, was calculated using a spectrophotometer and the data were analyzed with oneway analysis of variance (ANOVA) and Tukeys honestly significant differences (HSD) tests (α=.05). RESULTS Significant differences in translucency among the control and test groups, and the B1 shaded group and other shades was observed. There were no significant differences among A2, A3, C2, and D2 shaded groups. CONCLUSION The translucency of the zirconium oxide cores was affected by the coloring procedure and significant differences in the translucency measurements were identified between specific shades.

KALSİYUM SİLİKA İÇERİKLİ PULPA KAPLAMA MATERYALİNİN IŞIK KAYNAĞININ ÜÇ FARKLI MODU İLE POLİMERİZASYONU ESNASINDA OLUŞAN ISI ARTIŞININ İNCELENMESİ

Pulp damage may occur because of the temperature rise during polymerization of light-cured dental materials. Aim: The purpose of this study was to evaluate three different curing modes of a light emitting diode (LED) on the temperature rise in the pulp chamber during polymerization of a light-cured resin-modified calcium silicate filled pulp-capping material. Material and Method: A straight-cut was made to the occlusal surface of an extracted molar ensuring 1 mm dentin thickness over the pulp. Pulpal circulation was simulated by water cycling through the pulp chamber with a defined flow pressure to simulate the clinical case. Temperature rise was measured during the light curing of capping material (Theracal, Bisco Inc.,USA). Three modes of light curing unit (Planmeca Lumion,Mectron,Italy) were used to polymerizate the material; fast (FP), slow rise (SRP) and soft (SP). Thermal changes were measured by a data-logger. The data were statistically analyzed by one-way ANOVA. Results: ANOVA test showed that pulp chamber temperature changes were influenced by the mode of light source. All groups showed significant differences between each other (P<0.05). The intrapulpal temperature changes induced by different modes were: (7.19±0.44°C) for FP, (6.62±0.34°C) for SRP, (6.10±0.37°C) for SP. Conclusion: Following conclusions were drawn; The intrapulpal temperature changes induced by various light modes were: FP, SRP and SP in descending order. All curing modes of light curing unit showed significant differences between each other. Light curing of the TheraCal with different polymerization modes of the same light unit resulted in more than 5.5°C increase in the pulp chamber