Emre Korkut

Antimicrobial and mechanical properties of dental resin composite containing bioactive glass

Background The aim of this study was to evaluate the antimicrobial efficacy and mechanical properties of dental resin composites containing different amounts of microparticulate bioactive glass (BAG). Methods Experimental resin composites were prepared by mixing resin matrix (70% BisGMA and 30% TEGDMA) and inorganic filler with various fractions of BAG to achieve final BAG concentrations of 5, 10 and 30 wt%. Antimicrobial efficacy was assessed in aqueous suspension against Escherichia coli, Staphylococcus aureus and Streptococcus mutans and in biofilm against S. mutans. The effect of incorporation of BAG on the mechanical properties of resin composite was evaluated by measuring the surface roughness, compressive strength and flexural strength. Results Under the dynamic contact condition, viable counts of E. coli, S. aureus and S. mutans in suspensions were reduced up to 78%, 57% and 50%, respectively, after 90 minutes of exposure to disc-shaped composite specimens, depending on the BAG contents. In 2-day-old S. mutans biofilm, incorporation of BAG into composite at ratios of 10% and 30% resulted in 0.8 and 1.4 log reductions in the viable cell counts compared with the BAG-free composite, respectively. The surface roughness values of composite specimens did not show any significant difference (p>0.05) at any concentration of BAG. However, compressive and flexural strengths of composite were decreased significantly with addition of 30% BAG (p<0.05). Conclusions The results demonstrated the successful utilization of BAG as a promising biomaterial in resin composites to provide antimicrobial function.

Effect of different surface treatments on the shear and microtensile bond strength of resin-modified glass ionomer cement to dentin

Abstract Objective. The aim of this study was to evaluate the effect of different surface treatments on the microtensile bond strength (μTBS) and shear bond strength (SBS) of resin-modified glass ionomer cement (RMGIC) to dentin. Materials and methods. Fifty-two extracted human molars were flattened to obtain dentin surfaces. For SBS assessment 40 teeth were divided into four groups according to their surface treatments (acid etching, Er:YAG laser QSP mode, Er:YAG laser MSP mode and control-SiC) (n = 10). A plastic cylinder was placed over the differently treated dentin surfaces and RMGIC was placed into the rings and polymerized. Twelve teeth were used for the μTBS test. The treated dentin surfaces described above were restored with 4 mm high RMGIC and light cured; then, the specimens were sectioned into serial sticks (n = 15) and μTBS and SBS were tested for failure in a testing machine with a 1 mm/min crosshead speed. The data were analyzed by one-way ANOVA and Tukey HSD tests (α = 0.05). Results. Acid etching showed significantly higher SBS than the other groups (p < 0.05). Er:YAG QSP and MSP-treated groups showed higher SBS values than the control group, but the difference was not statistically significant (p > 0.05). Er:YAG MSP showed the highest μTBS value followed by acid etching, whereas the control group exhibited the lowest value (p < 0.05) and the differences between the control group and Er:YAG QSP were not significant (p > 0.05). Conclusions. The application of Er:YAG MSP mode and acid etching to dentin can be used for improving the bond strength of RMGIC.

Evaluation of temperature changes in the pulp chamber during polymerization of pulp capping materials

Abstract Polymerization of resin-based materials leads to temperature rise, caused by the exothermic nature of the reaction and energy absorbed during polymerization. This temperature rise is influenced by intensity of light, composition of resins, and type of light source. This study evaluated thermal insulating properties of four photo-polymerizing pulp-capping agents in primary and permanent teeth. Roots of 80 primary and permanent teeth were removed. Class-I cavities were prepared on the occlusal surfaces of teeth. Materials used were TheraCal LC, Biner LC, ACTIVA BioACTIVE, and Calciplus LC and light sources were 3 M-Elipar and VALO LED. Temperature rise was measured using a J-type thermocouple. Data were statistically evaluated using ANOVA and Tukey`s tests (p = 0.05). VALO LED exhibited significantly lower temperature rise in all groups and temperature rise in primary teeth was significantly higher with all experimental materials (p < 0.05). The highest temperature change was observed in the Biner LC group (3.82 ± 0.58) and the lowest change in the Activa-BioACTIVE group (1.78 ± 0.34). The VALO LED light source caused a significantly lower increase in pulpal temperature compared with the 3 M-Elipar source. All tested materials and light sources maintained pulpal temperature under safe limits, with temperature increases not exceeding 5.5 °C.

HPLC analysis of eluted monomers released from dental composites containing bioactive glass

Abstract Objectives: The aim of the present study is to evaluate the released residual monomers from composite resins that contain different proportions of bioactive glass (BAG). Methods: Experimental resin composites were prepared by a resin matrix (50% BisGMA and 50% TEGDMA) and inorganic filler with BAG (5, 10 and 30%). Each resin composite was placed in the tooth cavity (n = 5). After polymerisation, samples were immediately immersed in 75% ethanol and 25% deionised water (6 ml) at 37 °C. Residual monomers (Bis-GMA, TEGDMA, HEMA and UDMA) that were eluted from the composites for 10 m, 1 h, 1 d, 7 d and 30 d were analysed by high-performance liquid chromatography (HPLC). The data were analysed with one-way ANOVA and Tukey HSD at a p < 0.05 significance level. Results: Among the time periods, the fastest released residual monomer was observed in the 10 m elution. The highest amount of released residual monomer from all groups (except the control group) was TEGDMA, whereas this was HEMA for the control group. The amounts of residual monomers eluted from BAG30 were significantly higher than other groups (p < 0.05). Conclusions: The release of the monomer increases in accordance with the increased BAG addition to the composite resins.

Çocuk hastalarda Er:YAG lazer ile çürük uzaklaştırılmasında ağrı algısının değerlendirilmesi: bölünmüş-ağız çalışması

Amac: Cocuk hastalarin dental tedavilerinde korku ve anksiyete onemli bir problem olarak karsimiza cikmaktadir. Curuk temizleme aletlerinin kullanimi esnasinda olusan agri, cogu cocuk ve yetiskinde dental korku ve anksiyeteyi tetikleyebilmektedir. Bu calismanin amaci; Er:YAG lazer ve geleneksel doner aletler kullanilarak curuk temizleme islemi uygulanan cocuklardaki agri algilarini degerlendirmek ve karsilastirmaktir. Gerec ve Yontem: Necmettin Erbakan Universitesi Dis Hekimligi Fakultesi Pedodonti Klinigine basvuran 120 cocuk hastanin daimi molar dislerindeki okluzal curukler, Er:YAG lazer ve konvansiyonel curuk temizleme yontemi olan yuksek ve dusuk hizli doner aletler kullanilarak uzaklastirildi. Tum restoratif islemler tek klinisyen tarafindan gerceklestirildi. Tedavi sonrasi tum cocuklardan Wong-Baker skalasindaki deger veya gorsellerden bir tanesini secmeleri istendi. Elde edilen verilerin degerlendirilmesinde Wilcoxon testi kullanildi ( α =0.05). Bulgular: Calisma gruplari arasinda istatistiksel fark gozlendi (p<0.05). Er:YAG lazer grubunda ‘canim acimiyor’ secenegi %20.83 oraninda secilirken; konvansiyonel yontem grubunda %6.66 bulundu. ‘Canim cok fazla aciyor’ secenegi hicbir grupta secilmedi. Sonuc: Calismadan elde edilen sonuclara gore; Er:YAG lazerlerin curuk temizleme amaciyla kullanilmasinin geleneksel doner aletlere kiyasla daha az agriya sebep oldugu ve cocuk hastalar icin daha konforlu ve kabul edilebilir bir yontem oldugu dusunulebilir.

Multidisciplinary treatment of avulsed teeth case report and 6 years follow-up

Tooth avulsion is defined as the complete displacement of the tooth out of its alveolar socket. Management of tooth avulsion in the permanent dentition often presents a challenge. Replantation of avulsed teeth is the most accepted treatment approach considering esthetic and functionality. The aim of this case report is to present the multidisciplinary treatment approach and long-term follow-up of a patient (9. ♀) with avulsed maxillary central teeth.