S. Uctasli

Bio: S. Uctasli is an academic researcher from Ankara University. The author has contributed to research in topics: Bond strength & Inlay. The author has an hindex of 13, co-authored 24 publications receiving 361 citations. Previous affiliations of S. Uctasli include Süleyman Demirel University & University of Birmingham.

The attenuation of radiation by porcelain and its effect on polymerization of resin cements

Abstract: The influence of porcelain thickness and opacity on the polymerization of two dual activated (microfine and hybrid) and one light irradiated (hybrid) resin cements was assessed by hardness measurements. The surface microhardness values of the upper and lower surface of 1 mm thick resin cement specimens were determined. Specimens were polymerized using 40s irradiation beneath different thicknesses and opacities of porcelain discs. The results showed that increasing the thicknesses and opacity of the porcelain produced a statistically significant decrease in microhardness of the resin-based cements. The effect of attenuation is less for the microfine cement than for the hybrids. In the case of hybrid cements, the light activated material performed better than the dual activated cement.

Microleakage of direct and indirect inlay/onlay systems

Abstract: summary The purpose of this in vitro study was to evalu ate the microleakage of direct and indirect inlay/onlay systems. Two of the groups investigated have indirect applications only and consist of microfine composites. The other two groups of inlay/onlay systems have both direct and indirect applications and are hybrid compos ites. Standardized MOD preparations were cut in 60 extracted human premolars. One gingival margin was placed in enamel above the cementoenamel junction (CEJ) and the other was placed in dentine below the CEJ. The inlays were made and luted according to each manufacturer's recommendation. The restored teeth were thermocycled and immersed in a basic fuchsin solution for 24 h. Following the mesiodistal sectioning of the specimens, extent of dye penetration at the restoration-glass ionomer cement and tooth-glass ionomer cement interfaces were scored using a stereomicroscope. Both direct and indirect inlays showed substantial leakage at gingival-dentine mar gins. However, there was only superficial leakage at enamel margins. Comparing the overall indirect inlay systems, EOS inlay leaked the most (P≤0.05). Indirect Brilliant Dentin® inlays showed a significantly smaller amount of leakage than the other inlay systems. SR- Isosit® and Estilux Posterior C VS® inlays provided a favourable marginal seal. In the case of Brilliant Dentin® and Estilux Posterior C VS®, indirect inlays leaked more than direct inlays. Generally, no significant difference was observed between the interfaces evaluated in microleakage performance.

Fracture resistance of anterior, posterior and universal light activated composite restoratives.

Abstract: This investigation measured the fracture resistance of a wide range of currently available light-activated-composite restoratives. Products intended solely for anterior use were tested together with universal materials and products intended for posterior application. All materials were handled according to manufacturers' instructions. For products evaluated in this investigation, universal and posterior materials yielded higher mean torque to fracture (T) values overall in comparison to the anterior products. One Microfilled and two Polyglas filled products designated for posterior application yielded relatively modest mean fracture resistance values.

The strength of a heat‐pressed all‐ceramic restorative material

Abstract: summary A heat-pressed technique (IPS Empress®, Ivoclar) has been described to construct single unit crowns, inlay/onlays and veneers using precerammed and precoloured glass-ceramic ingots. The aim of the study was to evaluate the strength of materials obtained using this technique. Strengths were determined by means of shell (disc rupture) tests. Seven groups of 10 specimens each were prepared with different combinations of core, incisal and glaze firing. Shell strength values of these seven groups varied between 167 ± 18 and 81 ± 9 MPa. After analysis, results showed that there was no statistical difference between groups when the core porcelain was in tension. However, there was a significant difference between those groups in which the lower surface was either core or incisal porcelain. The component thicknesses of the core and incisal materials did not change the strength of the complete specimen.

In vitro aging of dental composites in water--effect of degree of conversion, filler volume, and filler/matrix coupling.

Abstract: The purpose of this study was to evaluate the long-term effect of aging in water on the physical properties of experimental composites having systematically controlled differences in degree of conversion (DC), filler volume fraction (Vf), and percentage of silane-treated fillers. Composites were made with a 50% Bis-GMA:50% TEGDMA light-cured resin and a 1-2 microm (average size) strontium glass filler (+ 5 wt% SiO2 microfiller). For composites A-E, the DC was varied from 56-66% by changing the curing time; for D and F-I, the Vf was varied from 28-62 vol%; and for D and J-M, the percent of fillers with a silane coupling agent (gamma-MPS) was varied from 20-100%. Fracture toughness (KIc), flexure strength (FS), elastic modulus (E), and hardness (KHN) were tested after soaking in water at 37 degrees C for 1 day, 6 months, 1 year, and 2 years. The KIc was reduced 20-30% for all composites after 6 months, with minimal changes thereafter. The FS was reduced for several composites at 6 months, but only those with poor cure (A and B) were lower at 2 years than they were initially. The E was not reduced for most composites. Hardness was reduced for most composites after 6 months, but many returned to their original levels at 2 years. Long-term aging in water caused a reduction in the KIc, independent of composition, but had little effect on other properties, suggesting limited degradation of composites in water.