Begüm Güray Efes

Microleakage of repaired class V silorane and nano-hybrid composite restorations after preparation with erbium:yttrium–aluminum–garnet laser and diamond bur

The aim of this in vitro study was to compare the microleakage of repaired class V resin composite restorations prepared either by Er:YAG laser or a diamond bur. Ninety-six intact human molar teeth were randomly distributed into eight groups. In the first four groups, class V cavities (3 × 3 × 3 mm) prepared on the buccal and lingual surfaces of the teeth using an erbium:yttrium-aluminum-garnet laser (VersaWave, HOYA ConBio, Japan). Similar class V cavities were prepared in the second four groups using a diamond bur (S-Class, Komet, UK). Teeth in groups 1, 2, and 5, 6 were restored with a nano-ceramic composite (Ceram.X duo, DENTSPLY), whereas a silorane material (Filtek Silorane, 3M ESPE) was used to restore cavities in groups 3, 4, and 7, 8. Two different adhesive systems (XP Bond, DENTSPLY, and Silorane System Adhesive, 3M ESPE) were also used. All specimens were aged for 7 days. New cavities (3 × 3 × 3 mm) were prepared adjacent to the old restorations with Er:YAG laser (groups I–IV) or diamond bur (groups V–VIII). Different repair materials were then applied to the new cavities using the previous two restorative materials and two adhesive systems. All teeth were subjected to thermocycling (5,000 cycles between 5 and 55°C) and axial loadcycling (30 N, 1 Hz, 2,000 cycles). Specimens were immersed in 50% w/w silver nitrate solution. Teeth were sectioned longitudinally in buccolingual direction. Stereomicroscope (Nikon SMZ 800) and SEM (JEOL JSM 5600) were used to evaluate the microleakage that existed at the interface between the old restorations and the repair materials. Data were analyzed statistically with one-way ANOVA and Tukey tests (p < 0.05). Even though no statistically significant differences were found between any of the groups, the cavities repaired with different restoratives showed slight microleakage, especially those prepared by Er:YAG laser (p > 0.05). No microleakage scores were obtained in the groups repaired with Filtek Silorane/Filtek Silorane and Ceram.X/Ceram.X. All the substances tested can be used as repair materials for immediate repair after Er:YAG laser and diamond bur. All substances tested in this study can be used as immediate repair materials after cavity preparations with Er:YAG laser or diamond bur.

The effects of halogen and light-emitting diode light curing on the depth of cure and surface microhardness of composite resins

Aim: Light-emitting diode light curing units (LED LCUs) have become more popular than halogen LCUs in routine dental restorative treatment. The aim of the study was to compare the effects of two conventional halogen (Hilux Plus and VIP) and two LED (Elipar FreeLight 2 and Smart Lite) light curing units on the depth of cure and the microhardness of various esthetic restorative materials. Materials and Methods: The curing depth and microhardness of a compomer (Dyract Extra), a resin-modified glass ionomer (Vitremer), a packable composite (Sculpt It), an ormocer (Admira), a hybrid composite (Tetric Ceram), two microhybrid composites (Miris and Clearfil Photo Posterior) and, a nanofil composite (Filtek Supreme) were determined using a scraping method and a hardness tester. A total of 320 samples were prepared using the eight different materials (n = 10 samples for each subgroup). The scraping test was based on ISO 4049:2000. Vickers microhardness testing was carried out using hardness tester (Zwick 3212). Data were analyzed using one-way analysis of variance (ANOVA), Bonferroni and the Kolmogorov–Smirnov tests. Results: Best microhardness results were obtained with the LED light curing units and Tetric EvoCeram and Filtek Supreme achieved the highest hardness values. The nanofil composite, Filtek Supreme, showed the best curing depth results in all the tested light curing systems. Conclusions: The LEDs were found to be more successful than the halogen units with respect to both curing depth and microhardness properties.

Effects of ultrasonic and sonic scaling on surfaces of tooth‑colored restorative materials: An in vitro study

OBJECTIVE The effects of sonic and ultrasonic scalings (USSs) on the surface roughness of nanohybrid, flowable, and polyacid-modified resin composites and conventional glass ionomer cement were examined, and the effectiveness of repolishing on the scaled material surfaces was determined. MATERIALS AND METHODS The surface roughness of each sample was measured three times before and after each scaling and after repolishing, and the data were analyzed using repeated measuresanalysis of variance, Tukeys multiple comparisons, and paired t-tests by a statistical program. RESULTS Although sonic and USS both significantly increased the surface roughness of all the tooth-colored materials, USS roughened the surfaces of all the test materials more than SS did. Hence, USS may detrimentally affect tooth-colored restorative materials, especially conventional glass ionomers and compomers. Repolishing decreased the surface roughness of all the materials to near their baseline levels. CONCLUSIONS On the basis of these results, the repolishing of restoration surfaces is strongly recommended after dental scalings.

Effect of different clinical applications on physico-mechanical properties of composite resins

Although clinicians use fluoride agents to reduce the occurrence of caries, and surface sealing agents to protect composite restorations, the effects of these agents on composite resins have not yet been investigated. The goal of this study was to determine the effect of different surface applications (fluoride or surface sealant) on resin composites with different organic structures (Siloranes, Sonicfill, 3M Z550, Kalore). In this study, 120 discs and 120 bars made of composite resin were stored in water for three months before being thermally aged by cycling between 5°C and 55°C for 10,000 cycles. The discs were 15 mm in diameter and 1 mm thick; the bars were 25 × 2 × 2 mm. The surface sealant and fluoride were applied to the specimens, and evaluations were performed after 24h. Initial and final calculations were performed for flexural strength, microhardness, roughness, gloss, water sorption, and solubility. Silorane composite showed the lowest water sorption levels (p < 0.05) for both initial and aged groups. Silorane and SonicFill composite groups showed the lowest solubility (p < 0.05). Both before and after aging, the SonicFill group showed the highest values of flexural strength and microhardness. Silorane showed the highest roughness and lowest gloss values. Lower water sorption and solubility rates were seen on materials fabricated from hydrophobic monomers. High water sorption and solubility degrades the mechanical and surface properties. Fluoridation and surface sealant application can alter the surface properties but do not have any effect on the mechanical properties.

FİBER POST SİMANTASYONUNDA TÜKÜRÜK KONTAMİNASYONUNUN BAĞLANMA DEĞERLERİ ÜZERİNE ETKİSİ-EFFECT OF SALIVA CONTAMINATION DURING FIBER POST CEMENTATION ON MICROTENSILE BOND STRENGHT

OZET Bu calisma cam fiber post simantasyonunda farkli dental adesif ajanlarinin uygulanmasinin gerilme kuvvetine etkisini incelemek ve tukuruk kontaminasyonunun basari uzerine etkisini arastirmak amaciyla yapilmistir. Calismada 30 adet tek koklu dis kullanilmistir. Disler rastgele secilerek 6 gruba ayrilmistir (n=5). 1.grupta total-etch, 2.grupta self-etch adesif ajanlari ve her iki grupta dual cure kompozit recine siman kullanilarak fiber postlar simante edilmistir. 3.grupta self-etch adesif recine siman kullanilarak fiber postlar simante edilmistir. 4.grupta total-etch teknigi kullanilarak asit ve adesif ajan uygulamasindan sonra kontaminasyon yapilip fiber postlar kanala yerlestirilmistir. 5.grupta self-etch teknigi kullanilarak primer ve bonding islemlerinden sonra kontaminasyon yapilip fiber postlar kanal yerlestirilmistir. 6.grupta ise self adesif uygulamasindan once kontaminasyon yapilip fiber post kanala yerlestirilip simante edilmistir. Orneklere microtensile test cihazinda gerilme kuvveti 0.5 mm/dk hizla uygulanmistir. Verilerin istatiksel degerlendirilmesinde Kruskal Wallis analiz testi kullanilmistir. Cikan sonuclarda en yuksek degeri kontaminasyon yapilmamis total-etch ve self-etch gruplarinin gosterdigi (7.5 N/mm²), buna karsin self-adesif gruplarinin hem kontaminasyon yapilmamis (1.8 N/mm²) hem de kontaminasyon yapilmis gruplarinin (1.2 N/mm²) oldukca dusuk degerler gosterdigi saptanmistir. Anahtar Kelimeler: Adesif ajan, kontaminasyon, baglanma ABSTRACT The aim of this in vitro study was to evaluate effects of saliva contamination on microtensile bond strenght during cementation of glass fiber posts by using different adhesive materials. Thirty of one-rooted-teeth were used and divided into 6 groups (n=5). First group was cemented with using total etch adesive agent (3M Adper Single Bond), second group was cemented with using self etch adesive agent (3M Adper Prompt L-pop) and posts were cemented with dual cure resin cement. Third group was cemented by using self-etch self-adesive cement (Smart CEM Dentsply,). Forth group was cemented with using total etch adesive agent (3M Adper Single Bond), fifth group, self-etch system was contaminated with saliva and posts were cemented with dual cure resin cement. Sixth group, root canal was contaminated before self-adhesive cementation (Smart CEM Dentsply). Microtensile bond strenght tests were performed. Data were analized by Kruskall-Wallis variance analysis. Self-etch and total etch control groups (7.5 N/mm²) had showed the highest score (7.5 N/mm²) but self-adhesive control groups both contamination and control groups had showed the lowest rates (1.8 N/mm²). Key Words: Adhesive agent, contamination, microtensile bond strenght.