Emel Karaman

Does the temperature of beverages affect the surface roughness, hardness, and color stability of a composite resin?

Objective: To investigate the effect of beverages′ temperature on the surface roughness, hardness, and color stability of a composite resin. Materials and Methods: Fifty specimens of the Filtek Z250 composite (3M ESPE, Dental Products, St.Paul, MN, USA) were prepared and initial roughness, microhardness, and color were measured. Then the specimens were randomly divided into five groups of 10 specimens each: Coffee at 70°C, coffee at 37°C, cola at 10°C, cola at 37°C, and artificial saliva (control). After the samples were subjected to 15 min × 3 cycles per day of exposure to the solutions for 30 days, the final measurements were recorded. Results: After immersion in beverages, the artificial saliva group showed hardness values higher than those of the other groups (P < 0.001) and the microhardness values were significantly different from the initial values in all groups except for the control group. Both cola groups showed roughness values higher than the baseline values (P < 0.05), while the other groups showed values similar to the baseline measurements. When ΔE measurements were examined, the 70°C coffee group showed the highest color change among all the groups (P < 0.05). Conclusion: High-temperature solutions caused alterations in certain properties of composites, such as increased color change, although they did not affect the hardness or roughness of the composite resin material tested.

Effect of operator variability on microleakage with different adhesive systems

Objective: The objective of this study was to evaluate the effect of operator variability on microleakage with different adhesive systems. Materials and Methods: A total of 180 standardized Class V cavities were prepared on facial and lingual of 90 extracted human premolar teeth and randomly assigned to five groups according to the adhesive systems used (n = 36): Prime and Bond NT (PB), Single Bond (SB), Futura Bond NR, Xeno III (XE) and Adper Prompt-L-Pop (LP). The adhesive groups were then further subdivided into three operator groups according to level of clinical experience (n = 12): An undergraduate student, a research assistant and a faculty member. All cavities were restored with same composite resin. The restored teeth were thermocycled (500 cycles, 5-55°C) then immersed in 0.5% basic fuchsin and measured for leakage under a stereomicroscope. Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney U tests. Results: Significant inter-operator variation was found in the enamel margins in the XE group with significantly higher microleakage when used by the undergraduate student (P < 0.05). Although no significant differences in microleakage were found between adhesive systems for the research assistant and faculty member (P > 0.05), significant differences were observed between PB and LP, PB and XE, SB and LP and SB and XE in the enamel margins for the undergraduate student (P < 0.05). Conclusion: Microleakage of adhesive systems is more dependent on interactions between the operator and adhesive material than on the choice of adhesive material.

Effect of an Er,Cr:YSGG laser preparation on dentin bond strength of a universal adhesive

Abstract The aim of this study was to evaluate the bond strength of a universal adhesive system to dentin prepared with SiC paper or an Er,Cr:YSGG laser using different bonding strategies (etch-and-rinse versus self-etch mode). Ninety-six extracted caries-free, sound human molars were used. The teeth were longitudinally sectioned in the mesiodistal direction and were wet polished with 600-grit SiC paper to obtain a standardized flat dentin surface. All prepared teeth were randomly divided into two groups, according to the surface preparation method: GroupI:an erbium, chromium:yttrium,scandium, gallium, garnet laser; Group II: silicon carbide paper[SiC] (n = 48). Each group was then assigned into three subgroups according to the universal adhesive’s (Single Bond Universal) bonding strategies: (a) etch-and-rinse mode with phosphoric acid, (b) etch-and-rinse mode with a laser, (c) self-etch mode (n = 16). For surface preparation, the Er,Cr:YSGG laser was used at 3 W, 30 Hz with 140 μs pulse duration for 25 s. For etching mode, the laser was used at 1.5 W (60% air, 70% water). Cylinders of composite were fabricated on the bonding area and shear bond strength was determined using a universal testing machine. Failure modes were evaluated using a stereomicroscope. The data were analyzed using two-way ANOVA followed by the Bonferroni test (p < 0.05). Bonding strategies showed statistically significant differences in both the SiC-and laser-prepared groups (p < 0.05).Universal adhesive used in etch-and-rinse mode with acid showed significantly higher bond strength values than in self-etch mode (p < 0.05). The bond strength values did not differ according to the surface preparation method (p > 0.05). Irrespective of preparation method, using universal adhesive in etch-and-rinse mode with acid might improve dentin bond strength. Laser preparation did not affect the bond strength of the universal adhesive tested.

Cuspal deflection and microleakage in pre molar teeth restored with bulk-fill resin-based composites

The aim of this study was to assess the cuspal deflection and cervical microleakage of premolar teeth filled with a bulk-fill composite resin or bulk-fill flowable composite resin base, and comparison between them and a conventional dimethacrylate and a silorane-base composite resin. Forty maxillary premolar teeth were divided into four groups (n = 10), standardized large mesio-occluso-distal (MOD) cavities were prepared. The distance between cusp tips was measured before and after the cavity preparations with a digital micrometer. In Group 1 Quixfil was used with bulk-fill technique. Teeth in Group 2 were restored to within 2 mm of palatal cusp in a single increment with x-tra base. The remaining occlusal cavity was restored with GrandioSO. In Groups 3 and 4, the teeth were incrementally restored with GrandioSO and Filtek Silorane, respectively. Cuspal deflection was measured 5 min, 24 h, 1 week, and 2 weeks after the completion of restorations. Each restored tooth was subjected to thermocycling regime, and microleakage was assessed. Data were analyzed with Kruskal–Wallis and Mann Whitney U tests (p < 0.05). Groups restored with bulk-fill composites (Groups 1 and 2) showed similar cuspal deflection with the group restored incrementally with GrandioSO. A significant reduction in cuspal deflection was observed in Filtek Silorane restorations. None of the groups showed complete prevention of dye penetration. Group 2 showed the best marginal sealing. In Conclusion, conventional composite resin applied by incremental technique caused cuspal deflection similar to that of bulk-fill composites used as restorative or base. The flowable bulk-fill composites were superior to others in preventing microleakage.

The influence of blood and/or hemostatic agent contamination on Micro-TBS to dentin

Aim: The purpose of this study was to evaluate the effects of blood contamination and hemostatic agent Ankaferd Blood Stopper (ABS: Ankaferd Drug Inc, Istanbul, Turkey) on the microtensile bond strength of a self-etching adhesive. Material and methods: Flat dentin surfaces were created from 40-M teeth and randomly divided to four groups according to contamination and adhesive procedure. The specimens of Group 1 are contaminated with blood; ABS was applied to the specimens of Group 2 after blood contamination and applied to the specimens of Group 3 without blood contamination. Group 4 is control group and self-etching adhesive was applied to all specimens. Teeth were restored with a nanohybrid composite. The specimens were sectioned to the beams and microtensile testing was carried out and the data were statistically analyzed with analysis of variance test. Tukey’s honestly significant difference post hoc test was also performed for multiple comparisons to compare subgroups. Results: Group 4 had the highest strength value, followed by Group 3, while Group 1, which contacts only with blood, had the lowest strength value. Conclusion: ABS has a negative effect on the bond strength of one-step self-etching adhesive system.

Farklı adeziv sistemlerin dentine makaslama bağlanma dayanımı: in vitro çalışma

AMAC: Bu in vitro calismanin amaci kendinden puruzlendirmeli (self-etch) bir adeziv sistem ve kendinden puruzlendirmeli olarak da kullanilabilen iki farkli universal adeziv sistemin dentine makaslama baglanma dayanim degerlerinin karsilastirilmasidir. GEREC VE YONTEM: Bu calismada cekilmis 36 adet curuksuz insan molar disi kullanildi. Disler akril kaliplara gomuldukten sonra okluzal mine yuzeyleri asindirildi, duzgun bir dentin yuzeyi elde etmek icin once 200 grid ve ardindan standart smear tabakasi elde etmek icin 600 grid silikon karbid disklerle su sogutmasi altinda zimparalandi. Elde edilen ornekler, kullanilan adeziv sisteme gore rastgele 3 gruba ayrildi (n=12): Grup 1: Single Bond Universal (universal adeziv), Grup 2: All-Bond Universal (universal adeziv), grup 3: Clearfil-SE Bond (kendinden puruzlendirmeli adeziv). Adeziv uygulanmis yuzeylere 2 mm capinda, 2 mm yuksekliginde teflon kaliplar kullanarak kompozit rezin silindirler baglandi (Tetric N-Ceram). Ornekler 24 saat distile suda bekletildikten sonra kafa hizi 0.5 mm/dk olan Instron universal test cihazina yerlestirildi ve makaslama baglanma dayanimlari olculdu. Veriler tek yonlu varyans analizi (ANOVA) ve Tukey HSD testleri kullanilarak degerlendirildi. Istatistiksel anlamlilik duzeyi p=0.05 olarak kabul edildi. BULGULAR: Single Bond Universal ile Clearfil SE grubunun makaslama baglanma dayanim degerleri arasinda istatistiksel olarak anlamli bir fark bulunmadi (p > 0.05). All-Bond Universal grubu diger gruplara gore istatistiksel olarak daha dusuk baglanma degerleri gosterdi (p < 0.05). SONUC: Single Bond Universal adeziv sistemi kendinden puruzlendirmeli olarak kullanildiginda, kendinden puruzlendirmeli adeziv sistemler icin altin standart olarak kabul edilen Clearfil SE Bond ile benzer dentine baglanma degerleri gosterdi.