Flexural strength and microhardness of anterior composites after accelerated aging

This study aimed to evaluate the flexural strength and microhardness of three different anterior composites after 10 000 thermocycles. The mechanical properties of a nano-fill composite (Filtek Ultimate Universal Restorative (FUR) (Enamel)), a nano-hybrid composite (Clearfil Majesty ES2 (ES2) (Enamel)), and a micro-hybrid composite (G Aenial Anterior (GAA)) were investigated in this study. For the microhardness test, 8-mm diameter and 2-mm thickness composite discs were used (n = 10), and for the flexural strength test, 25x2x2 mm bar-shaped specimens were prepared (n = 13). The specimens were tested at 24 h and after 10 000 thermocycles. Data were analyzed using two-way analysis of variance and the post-hoc Tukey test (p .05). Pearson correlation analysis revealed that there was a negative relationship between the mean hardness and flexural strength values (correlation coefficient = -0.367, p = .043). After 10 000 thermocycles, microhardness values of each material and flexural strength of ES2 and GAA decreased significantly according to 24 h. The nano-fill composite FUR displayed significantly higher microhardness values. However, each resin composite was statistically similar for flexural strength values. Ten thousand thermocycles significantly affected microhardness and flexural strength

Bond Strength of Different Composite Resin Materials and CAD/CAM Restorative Materials to Each Other and Dentin Tissue

Objective:The aim of the current study is to investigate the strongest and weakest points of the three different structures of prosthodontic restorations constituting the coronal structure when considered as a whole: the remaining tooth, composite resin, and computer-aided design and computer-aided manufacturing (CAD/CAM) restorative materials.Methods:Seventy extracted caries-free molars, CAD/CAM blocks [Lava Ultimate (LU), Vita Enamic (VE), IPS e.max CAD (IPS)], and composite resin materials Clearfil Majesty Posterior [CMP], Light Core [LC], Filtek Bulk Fill Posterior [FBP], EverX Posterior [EP] were used for this study. Dentin and CAD/CAM sections were embedded in acrylic. Clearfil SE Bond was used as adhesive material. Composite resin materials were applied to the dentin surface using a Teflon mold. LU and VE were sandblasted with 50-μm Al2O3 for 10-sec. IPS was etched with HF for 20-sec. Ceramic Primer-2 was applied to the surfaces. Composite bars (2.3x3 mm) were adhered to CAD/CAM blocks using RelyX-U200. In addition, CAD/CAM bars were also adhered to dentin. The shear bond strength test was performed. Failure modes were examined using a stereomicroscope. Differences were analysed using one-way ANOVA and Tukey Post Hoc test.Results:The highest shear bond strength values of the composite resin materials to dentin tissue were observed in EP (p<0.05). Shear bond strength values of composite resin materials to IPS were found higher than to LU and VE. The shear bond strengths of the three different CAD/CAM restorative materials to the dentin tissue were statistically similar.Conclusion:The type of composite resin materials affects the shear bond strength to dentin tissue and CAD/CAM restorative materials. However, the type of CAD/CAM restorative material does not affect the shear bond strength to dentin tissue

EFFECT OF ANTI-HALITOSIS-MOUTH RINSES ON SURFACE PROPERTIES OF RESIN BASED RESTORATIVE DENTAL MATERIALS

Objectives: This in-vitro study aimed to investigate the effect of five different types of mouth rinses used for halitosis on color stability and surface roughness of two types of restorative materials. Materials and Methods: In this study, a total of 120 disc-shaped samples (10x2mm) were prepared with nano-hybrid resin composite (Filtek Z550) and giomer (Beautifill II) materials. Randomly selected samples were divided into six groups as five different mouth rinses (Listerine Fresh Burst, Listerine Total Care, Colgate Plax, Oderol, Halitosil) and a control group (distilled water). Initial color values were measured by spectrophotometer (Easyshade Compact) according to the CIELAB system, and roughness values (Ra) were measured by contact profilometer (Surtronic 25). All specimens were incubated in mouth rinses at 37° C for 12 hours and measurements were performed in the same procedure. Data were analyzed by using Kruskal-Wallis H and Bonferroni Post Hoc tests with the SPSS 24.0 program at a significance level of 0.05. Results: The results of this study showed that there was not a statistically significant increase in surface roughness values. There was a significant change in CIELAB values in all of the Beautifil II materials after the immersion in mouth rinses (P&lt;0.05). There was a statistically significant difference between the color change values of Beautifil II and Filtek Z550 materials kept in the same mouth rinses (P&lt;0.05). Beautifil II was exhibited color change with values above the clinically acceptable limit (ΔE&gt;3.3). Conclusions: Color changes occurred in both of the restorative materials kept in different mouth rinses

Effect of the surface dehydratation (Ethanol-Wet Bonding) on the microleakage scores of the two current self etch adhesive system

Amaç: Bu çalışmanın amacı, adeziv sistem uygulamalarından önce kavite yüzeylerine etanol uygulamasının, günümüzde kullanılmakta olan iki adet self-etch sistemin mikrosızıntı skorları üzerindeki etkisini araştırmaktır. Materyal-Metot: Çalışmamızda, 28 adet çürüksüz, insan üçüncü molar dişin bukkal yüzeylerine, mine-sement birleşiminde sınıf V kaviteler hazırlanmıştır. Çalışmada, iki aşamalı Clearfil SE Bond ve tek aşamalı Clearfil S3 Bond, üretici firma önerileri doğrultusunda veya adeziv sistemlerin uygulanmasından önce kavitelere %95’lik etanolun 30 sn uygulanmasını takiben uygulanmıştır (n=7). Bağlayıcı uygulamasının arkasından, kompozit materyali ile restorasyonlar tamamlanmıştır. Restorasyonları tamamlanan örneklere, 5°C ile 55°C arasında 1.000 devir termal siklus işlemi uygulanmıştır. Termal siklus uygulamasından sonra, örnekler %0,5’lik metilen mavisinde 24 saat bekletilmiştir. Boyadan çıkartılan örneklerden dikey kesitler alınarak, boya sızıntısı skorlanmıştır. Elde edilen sonuçların istatistiksel değerlendirilmesi, Kruskal- Wallis ve One- way ANOVA testleri ile yapılmıştır. Bulgular: Bu çalışmada, etanol uygulaması yapılan örnekler ile adeziv sistemlerin üretici firma doğrultusunda uygulandığı örneklerin mine duvarlarında, Clearfil SE Bond ile Clearfil S3 Bond benzer sızıntı skorları sergilerken, dentin duvarlarında Clearfil SE Bond, Clearfil S3 Bond’dan daha düşük sızıntı sergilemiştir (p>0,05). Kavite yüzeylerine adeziv sistemlerin uygulamasından önce etanol uygulanması, her iki adeziv sisteminde mine ve dentindeki sızıntı skorlarında anlamlı bir değişiklik yapmamıştır (p>0,05). Sonuç: Self etch adeziv sistemlerin dentin duvarlarındaki mikrosızıntı skorları, yüzeylere etanol uygulaması sonucu hafif düzeyde azalırken, mine duvarlarındaki sızıntı skorları bu uygulamadan etkilenmemiştir. Bağlayıcı ajan uygulamasından önce etanol uygulanan dentin yüzeyleri, self-etch sistemlerin uzun dönem adezyonu için daha gelişmiş bir yüzey sağlayabilir.Objective: The purpose of this study was to investigate the effect of surface pretreatment with ethanol before bonding procedure, on the microleakage of two current self-etch adhesive systems. Material-Method: Class V cavities were prepared on the facial surfaces of 28 non-carious, human third molar teeth at the cemento-enamel junction. A two-step self-etch adhesive Clearfil SE Bond and a one-step self-etch adhesive Clearfil S3 Bond were applied to the cavities directly, according to the manufacturer’s instructions or after pre-treatment with 95% acetone for 30s before bonding (n=7). After bonding, the cavities were filled with a resin composite. The teeth with completed restorations were thermocycled 1,000 cycles between 5°C and 55°C. After thermocycle, the teeth were immersed in 0,5% methylene blue dye for 24 hours. The specimens that removed from dye were then sectioned longitudinally and dye penetration was scored. Data were analyzed using Kruskal- Wallis and One-way ANOVA tests. Results: The microleakage scores of Clearfil SE Bond and Clearfil S3 Bond, used directly or with ethanol pre-treatment to the cavity surfaces, were similar at enamel walls, the scores of Clearfil SE Bond were slightly reduced on dentinal walls when compared with Clearfil S3 Bond (p>0,05). The pretreatment of ethanol before bonding system application to the cavity surfaces had no significant effect on the microleakage scores of two adhesive systems on enamel and dentin. Discussion:: The microleakage scores of self-etch adhesive systems on dentinal walls of the teeth were slightly reduced after ethanol pre-treatment, but the scores on enamel walls were not affected. The ethanol pre-treated dentin surfaces may provide an improved substrate for resin adhesion of selfetching adhesives due to the dentin dehydration in long terms