Effect of Different Surface Treatments on the Repair of Aged Bulk-Fill Composites: An In Vitro Study

Objectives: The aim of this in vitro study was to evaluate the efficiency of different surface treatments on the microtensile bond strength (µTBS) of aged bulk-fill composite.Materials and Methods: Sixty bulk-fill resin-based composite (RBC) specimens in 5 x 5 x 5 dimensions were prepared. After the aging by thermal cycling for 5000 times between 5 and 55°C, substrate surfaces were abraded with SiC abrasive papers. Specimens were divided into 6 groups according to the surface treatment protocol: no surface treatment (control), control + Single Bond Universal (SBU; 3M ESPE) application, phosphoric acid etching (PA) + SBU, hydrofluoric acid  etching (HF) + SBU, aluminum oxide air abrasion (AlO) + SBU, and tribochemical silica coating (TSC) + SBU. Surface roughness values were measured in five different directions using a contact profilometer (n=10). Then, specimens were repaired with a conventional RBC. After the repair, bonded specimens were cut into 1 mm2 beams and µTBS values were determined until failure at a crosshead speed of 0.5 mm/min. Specimen surfaces after surface treatments were observed by SEM. Data were analyzed using  ANOVA and Tukey tests (p<0.05). Results: One-way ANOVA revealed significant difference (p<0.001) among the surface treatments. The lowest repair µTBS values were observed for the control group. SBU application alone significantly improved repair µTBS values (p<0.001). The highest µTBS values were obtained for the AlOand TSC, and HF followed. The surface roughness ranking for the five surface treatment protocols was as follows: TSC > AlO > HF > PA = Control. Conclusions: Aged bulk-fill RBCs can be successfully repaired if effective and safe repair protocol is chosen. The highest µTBS values were obtained for the AlO and TSC. The use of universal adhesive alone is promising to facilitate the repair of bulk-fill RBCs

Fluoride release of giomer and resin based fissure sealants

Fissure sealants are applied to teeth to prevent caries development. The presence of the fissure sealant creates a protective barrier, which prevents plaque accumulation to the pits and fissure. They have a significant role in preventing pit and fissure caries. The aim of this study was to evaluate the time-dependent fluoride ion release of giomer- and resin-based fissure sealants. Fissure sealants were divided into 4 groups: BeautiSealant (Shofu, Japan), Clinpro Sealant (3M ESPE, USA), Helioseal F (Ivoclar Vivadent, Liechtenstein), Fissurit F (Voco, Germany). Disk shaped samples were prepared for each sealant material tested, and they were transferred into polyethylene vials containing 5 ml of deionized water. Fluoride ion diffusion was determined on days 1,2,3,7,14,21, and 28 (n=7). The fluoride concentration in these samples was analyzed using a pre-calibrated spectrophotometer in parts per million (ppm). These experiments were performed in triplicates at room temperature. ANOVA and Tukey’s HSD test were used for statistical analysis. BeautiSealant was released the highest amount of fluoride on day 1 (5.33 ppm), followed by a sudden decrease on the day 2 (2.17ppm). The burst effect was observed only in this group. Clinpro Sealant, Fissurit F and HelioSeal F groups presented fluoride release of 2.69, 2.94 and 2.91 ppm on the first day, respectively, without a significant difference (p > 0.05). After the first week, a constant fluoride release level has been reached. The fluoride release for the three resin-based fissure sealants was slightly lower than that for the giomer-based. After the first week, materials exhibited no significant difference and reached a plateau. The usage of a high and prolonged fluoride-releasing fissure sealant material should be considered by clinicians, particularly in patients with caries risk.Los sellantes de fosas y fisuras se utilizan con el objetivo de prevenir el desarrollo de caries. La presencia del sellante crea una barrera protectora, que evita la acumulación de placa en las fosas y fisuras. Tienen un papel importante en la prevención de la caries. El objetivo de este estudio fue evaluar la liberación de iones fluoruro  de los sellantes de fosas y fisuras a base de Ionómeros y resinas. Los sellantes de fosas y fisuras se dividieron en 4 grupos: BeautiSealant (Shofu, Japón), Clinpro Sealant (3M ESPE, EE. UU.), Helioseal F (Ivoclar Vivadent, Liechtenstein), Fissurit F (Voco, Alemania). Se prepararon muestras en forma de disco para cada material, y se transfirieron a viales de polietileno que contenían 5 ml de agua desionizada. La difusión de iones fluoruro se determinó en los días 1,2,3,7,14,21 y 28 (n=7). La concentración de fluoruro en estas muestras se analizó utilizando un espectrofotómetro precalibrado en partes por millón (ppm). Estos experimentos se realizaron por triplicado a temperatura ambiente. ANOVA y la prueba de HSD de Tukey se utilizaron para el análisis estadístico. BeautiSealant liberó la mayor cantidad de fluoruro en el día 1 (5.33 ppm), seguido por una disminución repentina en el día 2 (2.17ppm). Los grupos Clinpro Sealant, Fissurit F y HelioSeal F presentaron una liberación de fluoruro de 2.69, 2.94 y 2.91 ppm el primer día, respectivamente, sin una diferencia significativa (p> 0.05). Posterior a la primera semana, fue alcanzado un nivel constante de liberación de fluoruro. La liberación de flúor para los tres sellantes de fosas y fisuras a base de resina fue ligeramente inferior a la de los Ionómeros. Después de la primera semana, los materiales no mostraron diferencias significativas. Los odontólogos deben considerar el uso de un material sellante de fosas y fisuras que promueva la liberación de flúor a lo largo del tiempo, especialmente en pacientes con riesgo de caries

Effect of polishing systems on fluoride release and surface roughness of different restorative materials

Secondary caries is an important factor in the replacement of the restorations, and it is thought that fluoride-releasing materials may prevent this problem. Furthermore, the fluoride release of the materials may be increased by polishing process. Available knowledge about the effect of polishing systems (PS) on the fluoride release of materials is limited. Therefore, this study was conducted to evaluate the effect of PS on the fluoride release of fluoride-containing materials. Restorative materials were divided into 6 groups: Fuji IX GP, Fuji II, Dyract XP, Beautifil II, Beautifil-Bulk, and Filtek Ultimate. Each group was also divided into four subgroups: Mylar strip, Sof-Lex Discs, Sof-Lex Diamond, and OneGloss. Fluoride release was determined using a fluoride ion-selective electrode. Surface roughness was evaluated with a profilometer. Two-way repeated measure and one- way ANOVA tests were used for statistical analysis. The initial rapid fluoride release was observed only in Fuji IX. The PS increased the fluoride release of Fuji IX and Fuji II and Dyract XP materials while reducing the fluoride release of resin-based materials. The highest surface roughness values were obtained with OneGloss. Further, a significant relationship between fluoride release and surface roughness was found. The polishing provides an increase in fluoride release, especially in glass-ionomer- based materials. This article revealed that there is a relationship between fluoride release and surface roughness. Proper PS must be chosen according to the material to provide the best clinical benefits in terms of fluoride release and surface roughness

Effectiveness of different resin composite materials for repairing noncarious amalgam margin defects

25th IEEE International Conference on Image Processing, ICIP 2018 -- 7 October 2018 through 10 October 2018 -- 143052Objectives: The specific objective of this in vitro study was to determine whether the current flowable resin composites can establish an effective seal in repairing noncarious amalgam margin defects. Material and Methods: A total of 30 freshly extracted caries-free human third molars were used for this investigation. Class I preparations with a standardized 160-µ marginal defect were made by condensing amalgam against a Mylar strip. Accelerated aging and corrosion protocols were then applied to simulate oral conditions. The prepared teeth were randomly divided into five groups (n = 6 per group) according to the repair material employed as follows: (1) no treatment (control); (2) self-adhering flowable resin composite (Vertise Flow); (3) flowable resin composite (Filtek Ultimate Flowable); (4) sonic-activated resin composite (SonicFill); and (5) self-adhesive cement (SmartCem2). Specimens were thermocycled again and then immersed in 5% methylene blue at 37°C for 24 h. For dye-leakage measurements, specimens were sliced longitudinally using a low-speed diamond disk. Results: The results indicated that the flowable resin composite material significantly reduced marginal microleakage compared to the control and SonicFill (P <0.05). Conclusion: Current flowable resin composites were found to be adequate materials for repairing noncarious amalgam margin defects

Mechanical properties and repair bond strength of polymer-based CAD/CAM restorative materials

Information on the mechanical properties and repairability of computer-aided design/computer-aided manufacturing (CAD/CAM) blocks is scarce. Five CAD/CAM blocks with similar indications were evaluated, including four resin nanoceramics, one polymer-infiltrated ceramic network (PICN), and one feldspathic ceramic. CAD/CAM blocks were sectioned into 4 mm x 1.2 mm x 13 mm bars for flexural strength (FS), and 4 mm thick blocks were prepared for elastic modulus (EM), nanohardness (NH), and microshear bond strength (mu SBS) testing. FS of the CAD/CAM blocks was determined using a three-point bending test, whereas EM and NH values were measured using a nanoindenter. The reparability of the tested block materials was determined by the mu SBS test. One-way ANOVA was conducted for FS, EM, NH, and mu SBS followed by Tukey's pairwise comparison (alpha < 0.05). FS ranged from 115 to 207 MPa, EM from 8.21 to 44 GPa, NH from 0.76 to 7.24, and mu SBS from 24.9 to 30.6 MPa. The findings of the present study revealed that resin nanoceramic blocks exhibited higher FS values than PICN and feldspathic ceramic, and they have acceptable mechanical properties for the fabrication of single-unit restorations according to the ISO 6872:2008. Furthermore, all CAD/CAM blocks tested can be successfully repaired regarding their recommended repair protocol

Effect of polishing systems on fluoride release and surface roughness of different restorative materials

Secondary caries is an important factor in the replacement of the restorations, and it is thought that fluoride-releasing materials may prevent this problem. Furthermore, the fluoride release of the materials may be increased by polishing process. Available knowledge about the effect of polishing systems (PS) on the fluoride release of materials is limited. Therefore, this study was conducted to evaluate the effect of PS on the fluoride release of fluoride-containing materials. Restorative materials were divided into 6 groups: Fuji IX GP, Fuji II, Dyract XP, Beautifil II, Beautifil-Bulk, and Filtek Ultimate. Each group was also divided into four subgroups: Mylar strip, Sof-Lex Discs, Sof-Lex Diamond, and OneGloss. Fluoride release was determined using a fluoride ion-selective electrode. Surface roughness was evaluated with a profilometer. Two-way repeated measure and one-way ANOVA tests were used for statistical analysis. The initial rapid fluoride release was observed only in Fuji IX. The PS increased the fluoride release of Fuji IX and Fuji II and Dyract XP materials while reducing the fluoride release of resin-based materials. The highest surface roughness values were obtained with OneGloss. Further, a significant relationship between fluoride release and surface roughness was found. The polishing provides an increase in fluoride release, especially in glass-ionomer-based materials. This article revealed that there is a relationship between fluoride release and surface roughness. Proper PS must be chosen according to the material to provide the best clinical benefits in terms of fluoride release and surface roughness.La caries secundaria es un factor importante para el reemplazo de restauraciones y se considera que los materiales que liberan flúor pueden prevenir este problema. Además, la liberación de fluoruro de estos materiales podría incrementarse mediante el proceso de pulido. El conocimiento disponible sobre el efecto de los sistemas de pulido (SP) en la liberación de fluoruro de los materiales es limitado. Por lo tanto, este estudio se realizó para evaluar el efecto de los SP sobre la liberación de fluoruro de materiales que contienen fluoruro. Los materiales de restauración se dividieron en 6 grupos: Fuji IX GP, Fuji II, Dyract XP, Beautifil II, Beautifil-Bulk y Filtek Ultimate. Cada grupo también se dividió en cuatro subgrupos: Banda Mylar, Discos Sof-Lex, Sof-Lex Diamond y OneGloss. La liberación de fluoruro se determinó usando un electrodo selectivo de iones fluoruro. La rugosidad de la superficie se evaluó con un perfilómetro. Se utilizaron medidas repetidas bidireccionales y pruebas ANOVA de una vía para el análisis estadístico. La liberación inicial rápida de fluoruro se observó solo en Fuji IX. El SP aumentó la liberación de fluoruro de los materiales Fuji IX y Fuji II y Dyract XP al tiempo que redujo la liberación de fluoruro de los materiales a base de resina. Los valores más altos de rugosidad de la superficie se obtuvieron con OneGloss. Además, se encontró una relación significativa entre la liberación de fluoruro y la rugosidad de la superficie. El pulido proporciona un aumento en la liberación de fluoruro, especialmente en materiales a base de ionómero de vidrio. Este artículo reveló que existe una relación entre la liberación de fluoruro y la rugosidad de la superficie. El SP adecuado debe elegirse de acuerdo con el material para proporcionar los mejores beneficios clínicos en términos de liberación de fluoruro y rugosidad de la superficie

Effect of surface treatments and universal adhesive application on the microshear bond strength of CAD/CAM materials

PURPOSE. The aim of this study was to evaluate the microshear bond strength (mu SBS) of four computer-aided design/computer-aided manufacturing (CAD/CAM) blocks repaired with composite resin using three different surface treatment protocols. MATERIALS AND METHODS. Four different CAD/CAM blocks were used in this study: (1) flexible hybrid ceramic (FHC), (2) resin nanoceramic (RNC), (c) polymer infiltrated ceramic network (PICN) and (4) feldspar ceramic (FC). All groups were further divided into four subgroups according to surface treatment: control, hydrofluoric acid etching (HF), air-borne particle abrasion with aluminum oxide (AlO), and tribochemical silica coating (TSC). After surface treatments, silane was applied to half of the specimens. Then, a silane-containing universal adhesive was applied, and specimens were repaired with a composite, Next, mu SBS test was performed. Additional specimens were examined with a contact profilometer and scanning electron microscopy. The data were analyzed with ANOVA and Tukey tests. RESULTS. The findings revealed that silane application yielded higher mu SBS values (P<.05). All surface treatments were showed a significant increase in mu SBS values compared to the control (P<.05). For FHC and RNC, the most influential treatments were AlO and TSC (P<.05). CONCLUSION. Surface treatment is mandatory when the silane is not preferred, but the best bond strength values were obtained with the combination of surface treatment and silane application. HF provides improved bond strength when the ceramic content of material increases, whereas AlO and TSC gives improved bond strength when the composite content of material increases

Efficacy of different surface treatments and universal adhesives on the microtensile bond strength of bulk-fill composite repair

The purpose of this in vitro study was to evaluate the influence of different surface treatments and aging on the microtensile bond strength (mu TBS) of bulk-fill composite resins. Bulk-fill composites (Filtek One; 3M ESPE) randomly received five different surface treatments: (1) no treatment, control, (2) 37% phosphoric acid etching (PA), (3) 9% hydrofluoric acid etching (HF), (4) air-borne particle abrasion with 50-mu m alumina particles (Al2O3), (5) tribochemical silica coating (CoJet). Following, the specimens were divided into three subgroups according to universal adhesive applied: Clearfil Universal Bond (CU; Kuraray), Prime&Bond Universal (PBU; Dentsply Sirona), or Single Bond Universal (SBU; 3M ESPE). A nanofill composite (Filtek Ultimate; 3M ESPE) was employed as a repair. Bonded specimens were stored in water for 24 h at 37 degrees C or thermal aged, then subjected to the mu TBS test. Additionally, specimens were analyzed with a contact profilometer and were evaluated with scanning electron microscopy. Control and PA treatments were showed the lowest mu TBS (p 0.05). Al2O3 and CoJet treatments generally exhibited a similar influence on mu TBS values. In addition, a correlation was found between surface roughness and bond strength (r = 0.831). CoJet resulted in significantly higher repair mu TBS values when compared to the other surface treatments. In addition, the use of silane-containing universal adhesive was increased the cohesive failure rate and maintained the repair mu TBS values after thermocycling