Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals

Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals were found in 79.9% of first molars and 72.8% of second molars. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. The most common root morphology of first and second molars is the two rooted morphology with three canals. Both the mesial and distal roots showed wide variations in canal anatomy with type IV and type I canal configuration predominating in the mesial and distal roots, respectively. Conclusion: Vertucci type I and IV canal configurations were the most prevalent in the distal and mesial roots, respectively, of both the mandibular first and second permanent molar teeth

Three-year clinical performance of two indirect composite inlays compared to direct composite restorations

Objective: Despite the incremental build-up of resin composite restorations, their polymerization shrinkage during curing presents a serious problem. Indirect composite resin systems represent an alternative in overcoming some of the deficiencies of direct composite restorations. The hypothesis of the present study states that the clinical performance of restorations may be affected by different generation and application techniques. Study Design: Sixty restorations (20 DI system (Coltène/Whaledent AG, Altstätten, Switzerland) composite inlays, 20 Tescera ATL system (BISCO Inc. Schaumburg, Illinois, USA) composite inlays, and 20 direct composites) were applied to premolar teeth in 49 patients. Restorations were clinically evaluated by two examiners. Data were analyzed using the Kruskal-Wallis, Mann-Whitney U, Wilcoxon Signed Ranks, and X2 tests. Results: The Tescera ATL system performed significantly better than both direct composite restorations (p<0.001) and DI system (p<0.05). Conclusion: Within the limitations of this 3-year clinical study, indirect resin restorations showed better scores than direct restorations. In addition, the Tescera ATL system was found to be more successful than the DI system and direct composite restorations

Influence of a short-time antioxidant application on the dentin bond strength after intracoronal bleaching

Karadas, Muhammet/0000-0002-3357-6896WOS: 000477493100001PubMed: 31290589This study evaluated the effects of an antioxidant application on the compromised bond strength of an adhesive to dentin bleached with 35% hydrogen peroxide. the dentin surfaces of the pulp chambers of 70 human third molars were ground, and the specimens were assigned randomly into seven groups, as follows: (a) control (unbleached); (b) bleached for 45 min, bonded immediately; (c) bleached for 45 min, treated with sodium ascorbate (SA) for 2 min, and bonded; (d) bleached for 45 min, bonded after 2 weeks; (e) bleached for 12 days, bonded immediately; (f) bleached for 12 days, treated with SA for 10 min, and bonded; and (g) bleached for 12 days, bonded after 2 weeks. in each group, the multimode adhesive was applied in etch-and-rinse and self-etch modes. the dentin surfaces were covered with a resin-based composite, and the bonded specimens were sectioned to produce composite-dentin sticks. the sticks were attached to a testing machine and subjected to a tensile force, and the representative specimens were examined via scanning electron microscopy. the bond strength was not affected by the application period of the bleaching agent. Both bleaching treatments significantly reduced the bond strength to the dentin in the self-etch or etch-and-rinse mode when compared with the control group. the bond strengths returned to normal levels with the SA applications or by waiting 2 weeks, regardless of the application period of the bleaching gel. the adhesive revealed a higher bond strength in the etch-and-rinse mode than in the self-etch mode

Evaluation of Color Stability and Surface Roughness of Bulk-Fill Resin Composites and Nanocomposites

WOS: 000419193400008Objective: the purpose of this study was to evaluate the color stability and surface roughness of four bulk-fill resin composites (SonicFill, Filtek Bulk Fill Flowable, X-tra fil, Filtek Bulk Fill Posterior) and three nanocomposites (G-aenial Universal Flo, Herculite XRV Ultra, Filtek Ultimate) after an aging simulation. Materials and Methods: the upper surfaces of prepared composite discs were polished with Sof-Lex discs. the samples were subjected to a thermocycling process for 3000 cycles, then immersed in the prepared mixture solution for two weeks. Before and after the aging simulation, profilometer and spectrophotometer were used to measure surface roughness (Ra) and color of the composite discs. the color change (Delta E) of each material was calculated. Results: the Delta E values showed a statistically significant difference among the studied materials (p<0.001). the Ra values of X-tra fil, Filtek Bulk Fill Flowable, SonicFill, and Filtek Bulk Fill Posterior were significantly increased by the aging process (p<0.001), while G-aenial Universal Flo, Filtek Ultimate, and Herculite XRV Ultra showed steady roughness (p<0.001). Conclusion: Filtek Ultimate showed greater susceptibility to staining. Microhybrid X-tra fil and nanohybrid SonicFill with higher filler amounts revealed more surface deterioration

Farklı Polimerizasyon Sürelerinin Rezin Kompozitlerin Mikrosertlik ve Dönüşüm Derecesi Üzerine Etkisi

Amaç: Bu çalışmanın amacı, farklı polimerizasyon sürelerinde bulk-fill ve konvansiyonel rezin kompozitlerin polimerizasyon özelliklerinin monomer dönüşüm derecesi (DC) ve mikrosertlik (MH) açısından değerlendirilmesidir. Materyal ve metod: Bu çalışmada, iki bulk-fill rezin kompozit (Filtek One Bulk Fill Restorative, X-tra Fil) ve iki geleneksel rezin kompozitten (Filtek Z550, Charisma Smart) hazırlanan disk şeklindeki örneklere (6 mm genişliğinde ve 2 mm yüksekliğinde) üç farklı polimerizasyon süresi (20 sn, 60 sn ve 100 sn) uygulandı. Polimerize edilen numunelerin DC'si bir FT-IR/ATR cihazı ile, MH değerleri ise bir Vickers sertlik cihazı ile ölçüldü. Elde edilen veriler istatistiksel yöntemlerle analiz edildi. Bulgular: FT-IR analizi ve Vickers mikrosertlik testi sonuçlarına göre 100 saniye ışık uygulanan grupların DC ve MH değerlerinin diğer gruplara göre anlamlı derecede büyük olduğu ortaya çıkmıştır (pObjective: The aim of this study was to evaluate the polymerization properties of bulk-fill and conventional resin composites in terms of the degree of conversion (DC) and microhardness (MH) at different polymerization times. Materials and Methods: In this study three different polymerization times (20 s, 60 s, and 100 s) were applied to disc shaped samples (6 mm wide; and 2 mm high) prepared from two bulk-fill resin composites (Filtek One Bulk Fill Restorative, X-tra Fil) and two traditional resin composites (Filtek Z550, Charisma Smart). The DC of the polymerized samples was measured with a FT-IR/ATR device, and the MH values were measured with a Vickers hardness device. The collected data were subjected to statistical analysis. Results: The results of the FT-IR analysis and Vickers microhardness test demonstrated that the DC and MH values of the groups exposed to 100 s of light curing were significantly higher than those of the other groups (

Fiber Postun Kök Dentinine Bağlanma Dayanımı Üzerine Bulk-Fill ve Self-Adhering Kompozit Rezinlerin Etkisi

Amaç: Bu çalışmanın amacı, bulk-fill ve self adeziv kompozitler ile yapıştırılan fiber postların kök dentinine bağlanma dayanımlarını değerlendirmektir. Yöntem: Bu çalışmada tek köklü ve tek kanallı 30 adet çekilmiş insan mandibular premolar dişleri kullanıldı. Diş kronları mine-sement hattından kesilerek kronları uzaklaştırıldı ve kanal tedavisi yapıldı. Post boşlukları post uzunluğuna göre hazırlandıktan sonra kökler, kullanılan materyale göre rastgele 5 gruba ayrıldı (n=30). Çalışmada 5 adet rezin bazlı materyal; RelyX U 200 (3M ESPE, Neuss, Almanya), Grandio Flow (VOCO, Cuxhaven, Almanya), Vertise Flow (Kerr, Kaliforniya, ABD), Filtek Bulk Fill Flowable (3M ESPE, Neuss, Almanya), SDR (Dentsply, Birleşik Krallık). kullanıldı. Bütün köklerden 1 mm kalınlığında horizontal kesitler alındı ve push-out bağlanma dayanımı testi uygulandı. Veriler Tek Yönlü ANOVA ve Tukey HSD Post-Hoc testleri kullanılarak analiz edildi. Bulgular: RelyX ≥ U 200 en yüksek bağlanma dayanım değerini göstermiştir(P<0,05). Vertise Flow SDR’ ye göre de daha düşük bağlanma dayanım değeri sunmuştur(P<0,05). Sonuç: RelyX U200 post uygulamalarında güvenle kullanılabilir.Objectives: The aim of this study is to evaluate the bond strength of fiber posts bonded with bulk-fill and self-adhesive composites to root dentin. Methods: In this study, 30 extracted human mandibular premolars with a single root and a single canal were used. The tooth crowns were cut from the enamel-cement line, the crowns were removed and root canal treatment was performed. After the post spaces were prepared according to the post length, the roots were randomly divided into 5 groups according to the material used (n = 30). In the study, 5 resin-based materials; RelyX U 200 (3M ESPE, Neuss, Germany), Grandio Flow (VOCO, Cuxhaven, Germany), Vertise Flow (Kerr, California, USA), Filtek Bulk Fill Flowable (3M ESPE, Neuss, Germany), SDR (Dentsply, UK). was used. Horizontal sections with a thickness of 1 mm were taken from all roots and a push-out bond strength test was applied. Data were analyzed using One Way ANOVA and Tukey HSD Post-Hoc tests. Results: RelyX U200 showed the highest bond strength value (P<0,05). Vertise Flow showed lower bond strength value compared to SDR. (P<0,05). Conclusion: RelyX U200 can be used safely in post applications

Bonding performance of universal adhesives on composite repairs, with or without silane application.

Aim: This study aims to investigate the adhesive performance of three different universal adhesives to repair aged composite restorations, with or without the application of silane. Materials and Methods: A hundred and twenty resin composite samples were prepared, aged and randomly divided into 6 main Groups (single bond universal [SBU], All-Bond Universal [ABU], Futurabond U, Clearfil Tri-S Bond, Single Bond 2, and Clearfil SE Bond) and 2 subgroups (with or without silane). A microhybrid composite resin was placed on the aged composite surfaces and light cured. After a micro-shear bonding test, the fracture surfaces were examined under the scanning electron microscopy. Statistical analysis was performed using two-way ANOVA and Tukey's post hoc tests. Results: Among all the universal adhesives, SBU showed the highest bond strength values compared to the other two universal adhesives when used with and without silane (P > 0.05). Between ABU and Futurabond U, no significant difference was observed with silane (P > 0.05) and without silane (P > 0.05). Among conventional adhesives, there was no statistically significant difference (P > 0.05) both with and without silane. Conclusion: Within the limitations of this study, while SBU can be safely used with and without the application of silane, Futurabond U cannot be used without silane. © 2018 Journal of Conservative Dentistry | Published by Wolters Kluwer - Medknow