Single-shade universal resin composites (SsURC) are preferred in clinical practice to reduce time for shade selection and obtain good esthetic results. In this study, the static mechanical properties of seven new SsURCs were investigated, their spectral analyzes were performed and scanning electron microscopy (SEM) evaluations were presented. Charisma Diamond One/DO, Admira Fusion x-tra/AFX, Omnichroma/OC, OptiShade/OS, Essentia Universal/EU, Zenchroma/ZC, Vittra APS Unique/VU were used in a three-point bending test to determine flexural strength (F_S) and elastic modulus (E_M); Vickers micro-hardness (VHN) and hardness-ratio (HR) were performed with a micro-hardness tester from top/bottom after 24-h/15-days of storage in distilled water at 37 °C (±1 °C). The degree of conversion (DC) was assessed by using Fourier transform infrared spectroscopy (FTIR). The structure of the resin matrix and filler content were assessed by SEM. Data were analyzed using IBM SPSS V23 and the R program and the significance level was taken as p < 0.05. The main effect of the tested SsURCs was found to be statistically significant on F_S, E_M, VHN, and DC values (p < 0.001). Bis-GMA free SsURCs (AFX, DO, VU) showed better DC and HR except for OC. All seven tested SsURCs conform to the requirements of ISO standards for dental resin composites for all tested categories.

Re-establishing a patient’s lost dental esthetic appearance is one of the most important topics for contemporary dentistry. New treatment materials and methods have been coming on the scene, day by day, in order to achieve such an aim. Most dentists prefer more conservative and aesthetic approaches, such as direct and indirect laminate veneer restorations, instead of full-ceramic crowns for anteriors where aesthetics is really important.

Objective. Maxillary anterior spacing is a common aesthetic complaint of patients. Midline diastema has a multifactorial etiology such as labial frenulum, microdontia, mesiodens, peg-shaped lateral incisors, agenesis, cysts, habits such as finger sucking, tongue thrusting, or lip sucking, dental malformations, genetics, proclinations, dental-skeletal discrepancies, and imperfect coalescence of interdental septum. Appropriate technique and material for effective treatment are based on time, physical, psychological, and economical limitations. Direct composite resins in diastema cases allow dentist and patient complete control of these limitations and formation of natural smile.Clinical Considerations. In this case report a maxillary midline diastema was closed with direct composite resin restorations in one appointment without any preparation. One bottle total etch adhesive was used and translucent/opaque composite resin shades were layered on mesial surfaces of the teeth that were isolated with rubber dam and Teflon bands. Finishing and polishing procedures were achieved by using polishing discs. Patient was informed for recalls for every 6 months.Conclusions. At one-year recall no sensitivities, discolorations, or fractures were detected on teeth and restorations. Direct composite resins seemed to be highly aesthetic and durable restorations that can satisfy patients as under the conditions of case presented.

Objective: This in vitro study was aimed to evaluate the color stability of resin-based composite materials in different viscosities immersed in various colorant solutions.Methods: 250 composite samples of A2 shades were prepared using two high-viscosity flowable composites (G-aenial Injectable, GC, Tokyo, Japan; Estelite Super Low Flow, Tokuyama Dental, Japan A2 shade), a bulk-fill flowable composite (Filtek Bulk-Fill, 3M, USA), a low-viscosity flowable composite (Filtek Ultimate Flowable, 3M, USA), and a packable composite (Filtek Ultimate, 3M, USA). Samples were polymerized and polished from both sides with a LED curing unit (Valo Grand, Ultradent, Switzerland) and polishing discs (SofLex, 3M, USA). Then divided by test groups (n=10 for each) regarding colorant solutions; coke (CocaCola Company, USA), tea (Yellow Label, Lipton, Rize, Turkey), coffee (Nescafe Classic; Nestle, Switzerland), red wine (Doluca, Öküzgözü, Doluca, İstanbul, Turkey), and physiologic saline as the control solution. Samples were discolored for 144 hours with solutions in an incubator at 37°C, and repolished after discoloration. Color measurements were performed using a clinical spectrophotometer (EasyShade IV, Vita, Germany) and a colorimeter (ShadeStar, Dentsply Sirona, USA). Two-way Anova test and Tukey HSD test were used for statistical analyses.Results: Composite material and colorant solution were considered effective factors for influencing the color change, regarding after discoloration scores (p<0.001, p<0.001, respectively). In addition, colorant solution was found more effective than the type of composite. Filtek Ultimate Flowable presented significantly the highest level of color change among others (p<0.001), for both ‘after discoloration (5,34 ± 3,78b)’ and ‘after repolishing (3,93 ± 2,23b)’ periods. No significant difference in color change was found between Gaenial Injectable, Estelite Super Low Flow, Filtek Bulk Fill Flowable, and Filtek Ultimate, and all showed imperceptible color changes (∆E*<3.7). Red wine solution showed significantly the highest level of color change (8,00 ± 2,08d) among other colorant solutions (p<0.001), and followed by coffee (4,59 ± 1,52c), tea (3,38 ± 1,21b), and coke (1,58 ± 0,99a), respectively. A strong relation was found between the spectrophotometer and colorimeter measurements.Conclusion: Viscosity was considered an effective factor for discoloration of RBCs. Color stability of high viscosity flowable composite materials were found to be good and similar to packable composite. Samples immersed in red wine showed the greatest level of discoloration and followed by coffee, tea, and coke. The repolishing procedure was considered effective for reversing back the surface discoloration of composite materials.