Fulya Toksoy Topçu

Evaluation of microhardness, surface roughness, and wear behavior of different types of resin composites polymerized with two different light sources

The microhardness, surface roughness and wear resistance of different types of resin composites, polymerized by a Quartz Tungsten Halogen (QTH) or Light Emitting Diode (LED) light curing units (LCU) were evaluated in this in vitro study. Cylindrical blocks were prepared from composites (8 mm in diameter, and 2 mm in thickness) and polymerized by a LED or a QTH LCU. Vickers hardness was measured on the top and bottom surfaces of the specimens. Surface roughness was measured with a surface profilometer on the top of the specimens. For the wear test, specimens were tested in a conventional pin-on-disc tribology machine under 15 N loads. The statistical analyses were performed by one-way analysis of variance (ANOVA) and t-tests, including the Bonferroni correction. Nanocomposite material Clearfil Majesty Posterior showed the highest hardness values in all polymerization types at the top and bottom surfaces (p < 0.05). Microhybrid Clearfil APX and hybrid Quixfil composites demonstrated the greatest surface roughness. Wear resistance of Clearfil Majesty Posterior was found to be the highest among the other tested resin composites. The results indicated that Clearfil Majesty Posterior demonstrated higher microhardness, less surface roughness, and higher wear resistance when compared with the other tested materials for both polymerization types.

Micro push-out bond strengths of 2 fiber post types luted using different adhesive strategies

OBJECTIVE The objective of this study was to evaluate the push-out bond strengths of carbon and glass fiber posts adhesively luted with Panavia F 2.0 and RelyX Unicem luting cements, as well as a modified application procedure using RelyX Unicem cement in combination with a single-bottle total-etch adhesive in 3 segments of teeth. STUDY DESIGN Sixty single-rooted human maxillary central incisors and canines were sectioned below the cementoenamel junction, and the roots were endodontically treated. The roots were divided into 2 fiber-post groups, and then divided into 3 subgroups of 10 specimens each to test different luting strategies. Bonded specimens were cut (1-mm-thick sections) and push-out tests were performed (crosshead-speed, 0.5 mm/min). Failure modes were evaluated using a stereomicroscope at original magnification ×40. RESULTS Micro push-out bond strengths were significantly affected by the type of luting agent and the type of post (P < .05). In all root sections, the push-out bond strength values of glass fiber posts were significantly higher than that of carbon fiber posts (P < .05). Moreover, the highest push-out bond strengths were measured for Panavia F 2.0 and RelyX Unicem cements. These values were significantly higher than that of modified application procedure in the medium section for both glass- and carbon-fiber posts, and in the apical root sections only for glass-fiber post (P < .05). In each region, the modified application procedure showed the lowest bond strength values. Adhesive failure between dentin and cement was the most frequent type of failure. CONCLUSIONS In all root segments, the glass fiber post provided significantly increased post retention compared with the carbon fiber post, regardless of the luting strategy used.

Retracted: Push-out bond strengths of two fiber post types bonded with different dentin bonding agents

The aim of this study was to evaluate the regional push-out bond strengths for two fiber-reinforced post types using three different dentin bonding agents. Sixty single-rooted extracted human first premolar teeth were sectioned below the cemento-enamel junction, and the roots were endodontically treated. Following standardized post space preparations, the roots were divided into two fiber-post groups (Glassix and Carbopost), and further divided into three subgroups of 10 specimens each for the bonding systems self-etching dentin bonding agents (Clearfil SE Bond and Optibond all-in-one), and total-etching dentin bonding agent (XP Bond). A dual-cure resin luting cement (Maxcem) was then placed in the post spaces and posts were then seated into the root canals polymerized through the cervical portion. The roots were then cut into 3-mm thick sections. Push-out tests were performed at a crosshead speed of 0.5 mm/min. The data were analyzed with multivariate ANOVA (alpha = 0.05). The morphology of interface between different dentin bonding agents from the cervical sections were analyzed with SEM. Glass fiber-reinforced posts demonstrated significantly higher push-out bond strengths than carbon fiber-reinforced posts (p < 0.001). Bond strength values decreased significantly from the cervical to the apical root canal regions (p < 0.001). Self-etching dentin adhesive Clearfil SE Bond and total-etching dentin adhesive XP Bond demonstrated similar bond strengths values and this was significantly higher compared with the Optibond all-in-one in cervical root canal region. In conclusion, in all root segments, the glass fiber-reinforced posts provided significantly increased post retention than the carbon fiber-reinforced posts, regardless of the adhesive used.

Root canal configurations of third molar teeth. A comparison with first and second molars in the Turkish population.

The purpose of the current study was to determine the similarities of maxillary and mandibular third molars with the other molar teeth. A total of 2016 extracted maxillary and mandibular permanent teeth were evaluated. The teeth were divided into six groups. The teeth were stored in 5% nitric acid solution for 7 days, then placed in increasing concentrations of ethyl alcohol. The teeth were rendered transparent by immersion in xylene solution for 4 days until complete transparency was achieved. Three roots were present in 93.0% of the maxillary molars, and 91.3% of the second molars. Among the maxillary third molars, 35.5% were single-rooted and 24.9% of the mandibular third molars had single roots. Double roots were present in 69.2% of the mandibular third molars, and 5.4% had three roots. Four new root canal configurations were encountered in this study. The root canal configurations of the mandibular and maxillary teeth showed similarities with the results of other studies performed in different populations.

The correlation between tooth brushing habit and familial education level in Turkish young population.

ÖZET Türk toplumundaki genç bireylerde diş fırçalama alışkanlığının aile eğitim düzeyi ile ilişkisi Bu çalışmanın amacı genç erişkin Türk popülasyonunda günlük diş fırçalama alışkanlığının çeşitli değişkenlere göre değerlendirmektir. Bu kesitsel çalışma 19-29 yaş aralığındaki 645 bireyde yürütüldü. Ailelerin eğitim durumu, sosyo ekonomik durumu, oral hijyen alışkanlıkları ve tutumları gibi bazı değişkenler anket ile toplandı. Diş fırçalama sıklığı sekiz gruba ayrıldı. İstatistiksel analiz için kikare test kullanıldı. Ortalama yaş 20,72 idi. Günde bir kere diş fırçalama alışkanlığı sıklığı %18.3 (n=118), günde birçok defalar diş fırçalama alışkanlığı %6.4(n=41) ve orduya katıldıktan sonra düzenli olarak diş fırçalama alışkanlığı 23.1(n=149) idi. Genç erişkinler arasında eğitimli olanlarda (p<0.05) diş fırçalama alışkanlığı daha fazlaydı. Genç erişkinler arasında diş fırçalama sıklığı ve ekonomik durumları arasında önemli derecede farklılık vardı. Ebeveynlerin ve kişilerin okur-yazarlık seviyesinin yüksek olması (sosyo-ekonomik durumun bir göstergesi olarak) diş fırçalama sıklığıyla örtüşmektedir. Diş fırçalama sıklığıyla kişinin ortalama geliri arasında korelasyon vardır. Ebeveynler çocuklarının ağız sağlığı konusunda model olarak rol alırlar.