Background: The aim of this study was to investigate the cytotoxicity of six different flowable composites with the methyl tetrazolium test (MTT). Materials and Methods: For MTT, six different flowable composites (Bisco Aelite, Bisco Inc., USA; Esthet X Flow, Dentsply, USA; Filtek™ Supreme XT Flowable Restorative, 3M Espe, USA; Gradia ® Direct Flo, GC, USA; Estelite ® Flow Quick, Tokuyama Dental Corporation, Japan; and Clearfil Majesty Flow, Kuraray Medical Inc., Japan) were prepared according to the manufacturer’s instructions in standard Teflon disks (2 mm × 5 mm) and the samples were extracted in 7 ml of Basal Medium Eagle with 10% new born calf serum and 5% penicillin streptomycin gentamisin for 24 h. In the experiments: The L929 cells were plated (25.000 cells/ml) in wells of 96 well-dishes and maintained in a humidified incubator for 24 h at 37°C, 5% CO 2 , and 95% of air. After 24 h incubation of the cells, the incubation medium was replaced by the immersed medium in which the samples were stored. Then L929 cells were incubated in contact with evaluates for 24 h. The cell mitochondrial activity was evaluated by the MTT. 12 well used for each specimen and MTT tests applied 2 times. The data were submitted to the statistically analyzed by one-way ANOVA and Tukey’s honestly significant difference (HSD) tests. Results: According to the results of MTT test with L-929 fibroblasts demonstrated that all freshly prepared flowable composites did not reduce vital cell numbers (P>0.05) in comparison to control group. Conclusion: This study revealed important information for clinical applications of flowable composites in dentistry.

ÖZETAmaç: Bu çalışmanın amacı iki farklı self-etch adeziv sistemin [Clearfil SE Bond (CSE) ve G-Bond (GB)] biyouyumluluk ve dentine bağlanma dayanımlarının değerlendirilmesidir. Gereç -Yöntem: Çalışma için 8 adet çekilmiş çürük-süz insan üçüncü azı dişi kullanıldı. Tüm dişlerin oklüzal yüzeyleri düz bir dentin yüzeyi elde etmek için dişin uzun eksenine dik olacak şekilde aşındırıldı. Dişler rastgele 2 gruba ayrıldı ve dişlerin oklüzal yüzeylerine adeziv sistemler üretici firmanın önerileri doğrultu-sunda uygulandıktan sonra Gradia Direct kompozit ile restore edildi. Örnekler, bağlantı ara yüzeyine dik olacak şekilde kesildi (bağlantı alanı: 1 mm 2 ) ve her grup için 15 çubuk elde edildi. Çubuklar daha sonra mikrogerilim bağlanma testine (Microtensile tester, Bisco, Schaumburg, IL, ABD) tabi tutuldu. Veriler tek yönlü varyans analizi kullanılarak analiz edildi. Biyouyumluluğun değerlendirilmesi için agar overlay testi yapıldı. 24 saat sonra inverted mikroskopla hücre dekolarizasyon zonu ve hücre lizis skorları tespit edildi. Veriler Kruskal wallis ve Mann withney U testi ile değerlendirildi. Bulgular: CSE (23.5 MPa), GB (18.9 MPa) dan daha yüksek bağlanma dayanımı gösterdi (p<0.05). Agar overlay testi sonuçlarına göre ise her iki adeziv de pozitif kontrol grubundan daha az hücre lizisi ve dekolarizasyon zonu gösterdi (p<0.001). Sonuç: Kullanılan bonding sistemlerin sitotoksisiteleri arasında istatistiksel olarak önemli bir fark olmadığı için daha yüksek bağlanma dayanımına sahip olan adeziv sistem (CSE) klinik olarak tercih edilebilir. Anahtar Kelimeler: Biyouyumlu materyaller, dentin yapıştırma ajanları, sitotoksisite testleri. ABSTRACT Objectives:The aim of this study was to evaluate the biocompatibility and dentin bond strengths of two different self-etch adhesive systems[Clearfil SE Bond (CSE) and G-Bond (GB)]. Materials and methods: Non-carious 8 extracted human third molar teeth were used in this study. The occlusal surfaces of all teeth were ground perpendicular to the long axis of each tooth to expose a flat dentin surface. The teeth were divided into two groups and adhesive systems were applied according to the manufacturer's instructions to the oclusal surfaces of the teeth and restored with Gradia Direct composite resin. The samples were sectioned perpendicular to the adhesive interface to produce sticks (adhesive area: 1 mm 2 ) and fifteen sticks were obtained for each group. All sticks submitted to microtensile bond strength test (Microtensile tester, Bisco, Schaumburg, IL, ABD). Data were analyzed using one-way varyans analysis ANOVA. An agar overlay test was used for the cytotoxicity evaluation. Cytotoxicity was examined by measuring the zones of cell decolorization and evaluating cell lysis by an inverted microscope after 24 hours. Data were analyzed using Kruskal wallis and Mann withney U test. Results: CSE showed higher dentin bond strength mean (23.5 MPa) than GB (18.9 MPa) (p < 0.05). Both bonding systems showed lower lysis scores than positive control material (p<0.001). Conclusions:The bondi...

The present in vitro study showed that water rinsing is necessary if cured adhesive resin is contaminated with saliva to ensure adequate bond strength.