Comparison of the mechanical properties of two giomer based bulk-fill, a hybrid bulk-fill and a nanohybrid composites with different application protocols: In vitro study

Amaç: Bu çalışmada, farklı tabaka kalınlıklarında uygulanan düşükve yüksek viskoziteli bulk-fill giomerler, bir nano-hibrit kompozit ve birbulk-fill hibrit kompozitin basma dayanımlarıyla bükülme dayanımlarınınkarşılaştırılması amaçlanmıştır. Gereç ve Yöntemler: Kompozit malzeme lerin basma dayanımlarının değerlendirilmesi amacıyla 6 grupta (n=10) top lam 60 adet silindir şeklinde örnek (6x3mm) hazırlanmıştır. Deney grupları aşağıdaki şekildedir:Grup 1 (G1) Tetric N-Ceram (TNC) (2+2+2 mm),Grup 2 (G2) Tetric N-Ceram Bulk-Fill (TBF) (4+2 mm),Grup 3 (G3) Beautifill Bulk-Fill Flowable (BBF) (4+2 mm),Grup 4 (G4) Beautifill Bulk Restorative (BBR) (4+2 mm),Grup 5 (G5) 2 mm BBF+4 mm BBR,Grup 6 (G6) 4 mm BBF+2 mm BBR.Örnekler 1 mm/dk kafa hızında basma dayanımı testine tabi tutulmuştur.Bükülme dayanımı ve bükülme modülüsünün hesaplanabilmesi amacıyla40 adet (25x2x2 mm) (n=10) kompozit örnek hazırlanmış [TNC (GF1), TBF(GF2), BBR (GF3), BBF (GF4)] ve 3 nokta bükülme testi (0,5 mm/dk) ger çekleştirilmiştir. Elde edilen veriler, tek yönlü ANOVA ve Tamhane T2 test leri kullanılarak değerlendirilmiştir (p0,05). GF4’ün ortalama bükülme dayanımı, GF1, GF2 ve GF3 grupla rından istatistiksel olarak anlamlı derecede yüksek bulunurken, diğer grup lar arasında anlamlı bir fark bulunamamıştır. Sonuç: En yüksek basma vebükülme dayanımı değerleri, bulk-fill giomerlerle elde edilmiştir. BBR al tında uygulandığında BBF kalınlığını 2 mm’den 4 mm’ye çıkarmak, basmadayanımını istatistiksel olarak anlamlı şekilde artırmıştır.Objective: This study evaluated the compressive strengthof low and high viscosity bulk-fill giomers, a nano-hybrid and a bulk-fillhybrid composites with varied layer thicknesses and evaluated their flex ural strength. Material and Methods: Sixty cylindrical specimens (6x3mm) in 6 subgroups were fabricated (n=10). The restorations were madeusing either:Group 1 (G1) Tetric N-Ceram (TNC) (2+2+2 mm)Group 2 (G2) Tetric N-Ceram Bulk-Fill (TBF) (4+2 mm),Group 3 (G3) Beautifill Bulk-Fill Flowable (BBF) (4+2 mm),Group 4 (G4) Beautifill Bulk Restorative (BBR) (4+2 mm),Group 5 (G5) 2 mm BBF+4 mm BBR,Group 6 (G6) 4 mm BBF+2 mm BBR.Compressive tests were performed at 1 mm/min. To determine the flexuralstrength and the flexural modulus, 40 specimens for each resin compositewere prepared [TNC (GF1), TBF (GF2), BBR (GF3), BBF (GF4)] (n = 10)(25×2×2 mm) and subjected to three-point bending test (0.5 mm/min). Datawere analyzed using one-way ANOVA and Tamhane’s T2 tests (p0.05). The mean flex ural strength of the GF4 was found statistically significantly higher thanthe GF1, GF2 and the GF3 groups, where no significant difference de tected between the other groups. Conclusion: The compressive and theflexural strength values of the bulk-fill giomers were found to be the high est. Increasing Beautifill Bulk Restorative (BBF) thickness 2mm to 4mmunder (Beautifill Bulk-Fill Flowable) BBR, improved the compressivestrength significantly

Effects of sports drinks on color stability of nanofilled and microhybrid composites after long-term immersion

Objectives: This study assessed the effects of three sports drinks on the color stability of two nanofilled and two microhybrid composite materials after 1-month and 6-month periods

Effect of surface sealant on the surface roughness of different composites and evaluation of their microhardness

PurposeThe aim of this study was to evaluate the effect of a surface sealant on the surface roughness of different composites and compare their microhardness values.Materials and MethodsSixty disc-shaped specimens were prepared and assigned to 6 groups (n = 10). Groups were prepared as follows; Group 1 (Herculite XRV Ultra), Group 2 (Beautifil Bulk Restorative) and Group 3 (Filtek Bulk Fill Posterior Restorative). Groups 4, 5, and 6 were prepared by applying a surface sealant (BisCover LV) on the specimens in groups 1, 2 and 3. Surface hardness of the discs in group 1, 2, and 3 and surface roughness of the discs in all groups were measured using the Vickers hardness test and a profilometer, respectively. One-way ANOVA was used to test for differences among the groups.ResultsNo significant differences were observed in the microhardness and roughness between the experimental and control groups for each restorative materials. Group 3 showed the highest surface hardness and group 4 showed the lowest surface roughness values.ConclusionUsing the BisCover LV resin after the polishing step has no significant effect on the surface roughness. The highest hardness values were obtained for the Filtek Bulk Fill Posterior Restorative after the polishing step. The smoothest surfaces were obtained for all experimental groups using the BisCover LV resin after the polishing step, Herculite XRV Ultra showed lower average roughness values than the other materials

Perception of Oral and Dental Health Awareness and Assessment of Dental Habits in Preclinical Dentistry Students: A Questionnaire Study

Aim: The oral and dental hygiene behaviors of patients are affected by their dentists. Although dental students attend preclinical courses in their first and second years of education, they are expected to be knowledgeable about oral and dental health due to their future position as being role models for patients. In this study, it was aimed to evaluate the oral and dental health awareness and oral health habits of preclinical dental students. Material and Methods: 127 preclinical dental students were included in this study. A questionnaire consisting of 39 questions about oral-dental health habits and knowledge levels was prepared. The results were analyzed with the SPSS 22.0 software. A p-value of smaller than 0.05 was considered statistically significant. Chi-squared and Mann-Whitney U tests were used for statistical analysis.Results: Frequency of daily tooth brushing, gingival bleeding, halitosis, toothpaste preference, satisfaction with tooth color and frequency of dental visits were found to be statistically significant. There was no significant difference between the 1st-year and 2nd-year student groups in terms of their responses to the questions (p> 0.05). A statistically significant difference was found between the male and female groups for their responses to the questions on topics such as toothpaste preference, satisfaction with the color of their teeth, frequency of dental examination, frequency of tooth cleaning and toothbrushing time (