Sezin Ozer

Shear bond strength of self-adhering flowable composite on dentin with and without application of an adhesive system

Purpose The aim of this study was to evaluate the shear bond strength (SBS) of conventional and self-adhering flowable resin composites on the dentin surfaces of primary and permanent teeth and to evaluate the effect of the application of an adhesive system under self-adhering flowable resin composite on SBS. Methods Prepared permanent and primary tooth dentin surfaces were randomly distributed into 3 groups according to application protocols as follows: group 1: Vertise Flow; group 2: OptiBond + Filtek Ultimate; and group 3: OptiBond + Vertise Flow. A universal testing machine was used to measure SBS of prepared specimens, and data were analyzed using 1-way ANOVA and Tukey test. Results Statistically significant differences were observed among all groups for primary and permanent teeth (P<0.05). The highest values were observed in group 2, followed by group 3, in both permanent and primary teeth. SBSs of all groups were significantly higher for permanent teeth than for primary teeth (P<0.05). Conclusion Although SBS values of Vertise Flow groups were lower than those for conventional flowable resin composite groups, with further developments in material technology, self-adhering materials could be promising materials especially for pediatric dentistry.

Bond strengths of silorane- and methacrylate-based composites to various underlying materials.

Objective. To evaluate shear bond strength (SBS) values of a methacrylate (FZ 250) and a silorane-based (FS) resin composite to various underlying materials. Materials and Methods. A total of 80 samples were prepared with four different underlying materials; a flowable (FLC) and a bulk-fill flowable composite (BFC), and a conventional (CGIC) and resin modified glass-ionomer cement (RMGIC). These underlying materials were laminated plus to methacrylate or silorane-based resin composites (n = 10). To evaluate the specimens SBS values were evaluated with a universal testing machine (cross-head speed; 1.0 mm/min). Statistical comparisons were carried out using two-way ANOVA and Tukeys post hoc test with a significance level of P < 0.05. Results. SBS values for FZ250 were significantly higher than for FS for all of the underlying materials tested (P < 0.05). SBS values of FZ250 to BFC were significantly higher than to all other materials (P < 0.05), whereas SBS values of FS did not vary significantly according to underlying material (P > 0.05). Conclusion. The use of FS in conjunction with any of the tested materials showed lower SBS than the FZ 250. Also, new low elastic modulus liner BFC presented slightly good interfacial adhesion so, the usage of BFC as an underlying material may be preferable for FZ 250.

Effect of a third-generation LED LCU on microhardness of tooth-colored restorative materials.

OBJECTIVE To assess the effects of different modes of a third-generation light-curing unit (LCU) (VALO) on the microhardness of restorative materials. DESIGN A microhybrid composite resin (Filtek(™) Z550), a giomer (Beautifil II), a compomer (Dyract eXtra) and a RMGIC (Photac(™) Fil) were used in the study. Three different modes of VALO were tested and a second-generation LCU (Elipar S10) was used as a control. The microhardness (VHN) was measured using a Vickers Hardness tester. Data were analyzed using two-way anova and post hoc Tukeys test (P < 0.05). RESULTS The Filtek Z550 group had the highest VHN values followed by Photac Fil, Beautifil II and the Dyract eXtra at both top and bottom surfaces, however the difference between Filtek Z550 and Photac Fil was not statistically significant for the bottom surfaces (P > 0.05). Of the different curing protocols tested, the VALO LCU in Mode 3 resulted in the lowest VHN values at both top and bottom surfaces (P < 0.05). CONCLUSION Based on the results of this study, it can be concluded that the high-power mode of the VALO LCU can be recommended for clinical applications especially in pediatric patients, as it can shorten the time required to adequately polymerize resin-based tooth-colored restorative materials.

Water Sorption, Solubility, and Color Stability of Giomer Restoratives

OBJECTIVES This study compared the color stability, water sorption, and solubility of a giomer composite and two nanohybrid composite resins. MATERIALS AND METHODS Disc-shaped specimens (1-mm thickness × 15-mm diameter) of a giomer (Beautifil II, Shofu, Kyoto, Japan) and two nanohybrid (Filtek Z550, 3M ESPE, St. Paul, MN, USA; Tetric N-Ceram, Ivoclar Vivadent, Schaan, Liechtenstein) composites (N = 10) were prepared. Baseline color measurements were taken, and specimens were immersed in water for 28 days. Following immersion, color values were remeasured, and color-change values (ΔE) were calculated. Water sorption and solubility were assessed by mass gain or loss after storage in water for 28 days. Data were analyzed with one-way analysis of variance and Tukeys post-hoc tests (p = 0.05). Pearsons correlation test was used to assess possible correlations between water sorption and solubility, water sorption and color stability, and solubility and color stability (p = 0.05). RESULTS Water sorbtion (%) and color change (ΔE) varied significantly among groups, with Beautifil II exhibiting the highest values (p < 0.001). No statistically significant differences were observed in water solubility values among the groups (p = 0.661); however, a linear, positive correlation was detected between solubility and discoloration (r = 0.368, p = 0.046). CONCLUSION Water sorption and discoloration values of the giomer composite group were significantly higher than those of the nanohybrids tested. CLINICAL SIGNIFICANCE The high levels of water sorption and discoloration of giomer composites are likely to have an adverse effect on esthetic restorations.

Solubility of Two Resin Composites in Different Mouthrinses

Aim. This study aimed to compare the solubility of a universal restorative resin composite (Filtek Z250; FZ250) and a silorane-based resin composite (Filtek Silorane; FS) after immersion in alcohol-containing mouthrinse, alcohol-free mouthrinse, and artificial saliva. Methods. 30 discs (10 mm × 1 mm) were prepared from each material and desiccated until a constant mass was obtained. Specimens were immersed in the test solutions for two days and desiccated again. Solubility was calculated based on the change in weight of each specimen before and after immersion. Data was analyzed using two-way ANOVA and Tukeys Post Hoc test (P < 0.05). Results. Solubility values for both resin composites were the highest in the alcohol-containing mouthrinse. FZ250 showed greater solubility than FS; the difference was only significant in artificial saliva. Conclusion. Both resin-composite materials tested exhibited some degree of solubility in each of the test solutions. The use of an alcohol-free mouthrinse may be preferable for patients with extensive composite restorations.

Evaluation of antifungal efficacy of QMix 2in1 as a final irrigant: An in vitro study

BACKGROUND It is known that no specific antifungal agent exists at present for irrigation of infected root canals. QMix 2in1 was investigated to determine whether they could be an alternative for sodium hypochlorite (NaOCl), chlorhexidine gluconate (CHX), and ethylenediaminetetraacetic acid (EDTA). OBJECTIVE The aim of this in vitro study was to evaluate and compare the antifungal efficacy of QMix 2in1, 5.25% NaOCl, 2% CHX, and 17% EDTA as a final rinse against Candida albicans (C. albicans). MATERIALS AND METHODS Ninety single-rooted mandibular premolar teeth were randomly divided into four experimental (n = 20) and two control (n = 5) groups. All root canals were instrumented with Mtwo rotary file system using crown-down technique to an apical size 40. Following root canal preparation, teeth were inoculated with C. albicans and incubated for 72 h. Teeth were irrigated with one of the following solutions as a final irrigant: (1) 5.25% NaOCl, (2) 2% CHX, (3) QMix 2in1, and (4) 17% EDTA. Aliquots from the samples were plated on 4% Sabouraud Agar, and colony-forming units were counted. RESULTS QMix 2in1, 5.25% NaOCl, and 2% CHX were equally effective (P > 0.05) and significantly superior to 17% EDTA in eradicating C. albicans (P < 0.05). CONCLUSION QMix 2in1 proved to be effective against C. albicans when used as a final rinse. According to the findings of the present study, QMix 2in1 may be recommended as an alternative final rinse solution.

Farklı polimerizasyon protokolleri ve yüzey uygulama metodlarının iki farklı fissür örtücünün makaslama bağlanma dayanım kuvveti üzerine etkisi

AMAC: Iki farkli rezin esasli fissur ortucunun [BeautiSealant (BS), UltraSeal XT hydro (UH)], fosforik asit (Ultra-Etch asit) veya primer (BeautiSealant Primer) uygulanarak, 3. nesil bir light emitting diode (LED) isik cihazinin iki farkli moduyla (Standart mod; 10 sn veya Xtra power mod; 3 sn) polimerizasyonu sonrasinda mineye makaslama baglanma dayanim kuvvetini in vitro olarak degerlendirmektir. GEREC VE YONTEM: Cekilmis 40 adet insan 3. molar disinden 80 adet mine ornegi elde edildi. Ornekler yuzey uygulama metodlarina, fissur ortucu tipine ve polimerizasyon protokollerine gore rastgele 8 alt gruba ayrildi (n=10). Gruplar; Grup 1: Asit + BS + Xtra power mod, Grup 2: Primer + BS + Xtra power mod, Grup 3: Asit + BS + Standart mod, Grup 4: Primer + BS + Standart mod, Grup 5: Asit + UH + Xtra power mod, Grup 6: Primer + UH + Xtra power mod, Grup 7: Asit + UH + Standart mod, Grup 8: Primer + UH + Standart mod seklinde idi. Orneklerin makaslama baglanma dayanim kuvveti (MBDK) degerleri Instron cihazi kullanilarak (1.0 mm/dk) olculdu. Elde edilen verilerin istatistiksel analizleri tek yonlu ANOVA ve Tukey’s testleri kullanilarak yapildi (p<0.05). BULGULAR: Gruplar arasinda istatistiksel olarak anlamli farkliliklar saptandi (p<0.05). BS grubunun tum alt gruplarinda MBDK degerleri UH grubunun tum alt gruplarindan dusuktu (p<0.05). Tum gruplar arasinda en yuksek MBDK degeri Grup 5’te, en dusuk Grup 1’de elde edildi. SONUC: Fissur ortuculerin MBDK degerleri, yuzey uygulama islemleri ve polimerizasyon protokollerinden etkilenebilmektedir.