Farklı adeziv uygulama tekniklerinin dentine mikrogerilim bağlanma dayanımlarının değerlendirilmesi

Amaç: Bu çalışmanın amacı, basitleştirilmiş adeziv sistemlerde farklı adeziv uygulama tekniklerinin dentine olan mikrogerilim bağlanma dayanımına (μTBS) etkisini değerlendirmektir. Gereç ve Yöntemler: Yetmiş iki adet çekilmiş çürüksüz insan üçüncü büyük azı dişi rastgele 18 gruba ayrıldı (n=4). Dentin yüzeyleri #600-grit silikon-karbit kağıt ile cilalandı. Kontrol grubunu Clearfil SE Bond [SE] (Kuraray), deney gruplarını iki aşamalı etch&rinse Adper Single Bond2 [SB] (3M ESPE) ve tek aşamalı self-etch Clearfil S3 Bond [S3] (Kuraray) oluşturdu. Test edilen adezivler, üretici firmanın talimatları [Kontrol] veya %2 Klorheksidin ile [CHX], veya iki kat adeziv uygulaması ile [x2K] veya ilave hidrofobik reçine tabaka [HR] ile uygulandı. Kompozit blok (Filtek Ultimate, 3M ESPE) tabaklama yöntemiyle oluşturuldu ve distile suda bekletildi (24 saat/37°C). 1mm2 reçine-dentin çubuklarına (Isomet) ayrılarak hemen [24sa] veya 37°C’de altı ay [6.ay] suda bekletildikten sonra μTBS testine tabi tutuldu (Bisco) (Çapraz kafa hızı 0.5 mm/dk). Veriler Three-way ANOVA ve post-hoc Tukey testleri kullanılarak analiz edildi (p0.05). Tüm grupların 6.ay µTBS değerleri anlamlı düzeyde azalmıştır (

Evaluation of adhesive interface degradation on bond strength with different adhesive applications.

EVALUATION OF ADHESIVE INTERFACE DEGRADATION ON BOND STRENGTH WITH DIFFERENT ADHESIVE APPLICATIONSThe purpose of this study was to evaluate the influence of 2% Chlorhexidine (CHX), double adhesive layer (DA), extra hybrophobic resin layer (HL) applications proposed to decrease adhesive interface degradation on the microtensile dentin bond strength of simplified adhe- sive systems.Two-step etch&rinse system Adper Single Bond2 [SB] and one-step self- etch system Clearfil S3 Bond [S3] were tested, two-step self-etch adhe- sive system Clearfil SE Bond [SE] was used as control. Seventy-two extracted human third molars dentin occlusal surfaces were exposed by grinding with 600-grit SiC paper. The adhesives were applied according to the manufacturer’s directions [MD], or with 2% Chlorhexidine [CHX] application or double application of the adhesive layer [DA] or following the manufacturer’s directions extra hydrophobic resin layer coating [HL]. After applying the adhesive resins, composite crowns were built up in- crementally. After 24-h water storage, the specimens were serially sec- tioned in“x”and“y”directions to obtain bonded sticks of about 1.0 mm2 to be tested immediately [IM] or after 6 months of water storage [6M] at a crosshead speed of 0.5 mm/min. The data from each adhesive was ana- lyzed by Three-way ANOVA (adhesive system, mode of application vs. storage time) and Tukey’s test (p = 0.05).After 6-months, all adhesives bond strength reduced significantly (p<0.01). SE showed the highest bond strength while no difference was found between SB-MD and S3-MD (p>0,05). Higher bond strengths values were observed for CHX, DA and HL applications, however HL and DA were significantly different from the manufacturer’s directions (p<0.01) and HL bond strength was the highest (p<0.01). When com- pared the adhesive systems only DA and HL application for S3 was significantly higher (p<0.01).The application of DA and HL can improve the resin-dentin bonds and decrease the adhesive interface degradation

The effect of endodontic irrigants on the microtensile bond strength of different dentin adhesives

WOS: 000427371000005PubMed ID: 29519974Objectives: The aim of this study was to determine the influence of irrigants on bond strength of adhesive systems. Materials and Methods: Superficial dentin surfaces of 60 extracted molars were divided into 15 groups, according to irrigants and adhesives. In the control groups, surfaces were irrigated with distilled water. In experimental groups, sodium hypochlorite (NaOCl), ethylenediaminetetraacetic acid (EDTA) + NaOCl, chlorhexidine (CHX), and NaOCl + sodium ascorbate were used as irrigants. Resin composites were then built up using Single Bond, Clearfil SE Bond, and Xeno 3 as adhesives. The microtensile bond strength of groups was determined. Data were statistically analyzed by two-way analysis of variance (ANOVA), one-way ANOVA, and the Bonferroni test. Results: NaOCl reduced bond strength of Single Bond and Clearfil SE Bond (P <0.01). For all adhesive systems, EDTA + NaOCl-treated groups exhibited lower bond strength than control groups (P <0.01). CHX decreased bond strength of Single Bond (P <0.01). Application of sodium ascorbate improved compromised bond strength to NaOCl-treated dentin (P <0.01). Conclusion: Different irrigants had several effects on bonding of different adhesives. Sodium ascorbate after NaOCl could restore compromised bond strengths

Effect of Preheating on Microhardness, Degree of Conversion, and Depth of Cure of Various Bulk-Fill Composites

Background: This study aims to evaluate the effect of preheating on microhardness, degree of conversion, and depth of cure of bulk-fill composites (Tetric EvoCeram Bulk-Fill, SonicFill2) and a conventional composite (Tetric EvoCeram). Methods: Layers of Tetric EvoCeram (2 mm), Tetric EvoCeram Bulk-Fill (4 mm), and SonicFill2 (5 mm) were placed in 4-mm diameter molds and polymerized at room temperature or heated to 55oC for 10 s with a total number of 60 samples. Then, the top surfaces of samples were polished. 30 samples’ Vickers microhardness was measured from the top and bottom surfaces. The other 30 samples were pulverized into a fine powder, and the composites’ degree of conversion was measured with attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Obtained data were analyzed statistically with a significance level of p&lt;0.05. Results: The degree of conversion of Tetric EvoCeram was higher than the minimum rate of clinically acceptable value, which is 55%, but the scores of Tetric EvoCeram Bulk-Fill and SonicFill2 were below the threshold. Preheating increased the degree of conversion of Tetric EvoCeram Bulk-Fill and SonicFill2. In addition, preheating did not affect depth of cure of SonicFill2 but decreased the rate of Tetric EvoCeram Bulk-Fill. Conclusion: The results showed that the effect of preheating on the degree of conversion and depth of cure varied according to the material. Keywords: Preheating, bulk-fill composite, degree of conversion, depth of cure, microhardness

II. sınıf adeziv restorasyonlarda farklı materyallerin ve restorasyon yöntemlerinin mikrosızıntı açısından in vitro değerlendirilmesi

Aim and purpose: The aim of this in vitro study was to evaluate the effects of different placement techniques and different restorative techniques on the microleakage with tooth clearing method in Class II cavities. Materials and method: Class II slot cavities (randomized on mesial or distal surfaces, 4 mm width, 5 mm height and 2 mm depth) were prepared on 50 sound nonerupted human third molars. The cavities were bonded with Scotchbond MP etch-and-rinse adhesive (3M ESPE) and were randomly divided into 5 groups (n = 10) according to the restorative techniques. Filtek Ultimate Universal nanohybrid composite and Filtek Ultimate Flow (3M ESPE) were used to restore all cavities. Group 1: Bulk, Group 2: Horizontal, Group 3: Oblique, Group 4: Horizontal, Indirect Polymerization (on replica), Luting with Flowable Composite, Group 5: Oblique, Indirect Polymerization (on replica), Luting with Flowable Composite. The specimens were thermocycled (500x) and immersed in 50% silver nitrate solution for 24 h. Microleakage on the gingival and proximal walls were evaluated with a stereomicroscope and calculated in the form of area after the application of decalcification and clearing method. Data were analyzed with Kruskal-Wallis and Mann-Whitney U-test (p &lt; 0.001). Results: Placement techniques and the usage of indirect polymerisation luted with flowable composite significantly reduced microleakage. There was no significant difference between the placement techniques but less microleakage scores were determined by using oblique placement technique. The significant fewer microleakage scores were determined in the Group 4 and Group 5. Summary and conclusions: Microleakage was observed in all groups. Indirect polymerisation technique combined with flowable composite were reduced microleakage