Clearfil Universal Bond Research Articles

Delayed light activation of resin composite affects the bond strength of adhesives under dynamic simulated pulpal pressure.

To evaluate the effect of a time delay before the light activation of resin composite on the microtensile bond strength (µTBS) of self-etch adhesives under dynamic simulated pulpal pressure. One hundred twenty crown segments were prepared from human third molars. Dentin surfaces were prepared with coarse diamond burs and connected to a dynamic pulpal pressure device. The self-etch adhesives used were Clearfil SE Bond (CSE), G2-Bond Universal (G2B), Clearfil Universal Bond Quick (CBQ), and G-Premio Bond (GPB). Each adhesive was divided into 3 subgroups: immediate light activation of resin composite (T0), delayed light activation for 150s (T1), and 300s (T2). The µTBS data were obtained after 24-h water storage. Scanning electron microscopy was used to evaluate the nanoleakage at the resin-dentin surface. The µTBS data were analyzed using two-way ANOVA and Duncan's multiple comparisons. All adhesives demonstrated a significant reduction in µTBS at T2, except for CBQ where the bond strength was not affected by the delayed light activation times. The two-step self-etch adhesives (CSE and G2B) demonstrated higher bond strength than the one-step adhesives at all conditions. Nanoleakage was observed in all adhesives at T2; however, nanoleakage was detected only in CBQ and GPB at T1. Delayed light activation of resin composite adversely affected the dentin bond strength of self-etch adhesives. Two-step self-etch adhesives had better bonding performance than one-step self-etch adhesives. After adhesive application, resin composite should be adapted and cured as soon as possible.

Influence of Irradiance and Exposure Times on the Mechanical and Adhesive Properties of Universal Adhesives with Dentin

This study evaluated the influence of irradiance/exposure time on the Knoop hardness (KHN) and polymer cross-linking density (PCLD), as well as microtensile bond strength (μTBS), nanoleakage (NL), and in situ degree of conversion (DC) of universal adhesives. Two universal adhesive systems, Clearfil Universal Bond Quick (CUQ) and Scotchbond Universal Adhesive (SBU), were light-cured using various irradiance/exposure times: 1400 mW/cm2 for 5 s (1400*5); 1400 mW/cm2 for 10 s (1400*10); 3200 mW/cm2 for 5 s (3200*5); and 3200 mW/cm2 for 10 s (3200*10). Adhesive disks from each group were used to measure PCLD by KHN. One hundred and twenty-eight human molars were randomly assigned to 16 groups according to the following variables: adhesive system vs adhesive strategies vs radiance/exposure times. After restoration, specimens were sectioned into resin-dentin sticks and tested for μTBS, NL, and DC. The data from PCLD (%), KHN, μTBS (MPa), NL (%), and DC (%) data were subjected to ANOVA and Tukey's test (α=0.05). Significant reductions in KHN, μTBS, and DC (p=0.00001) values and an increase in NL and PCLD (p=0.00001) values were observed for 3200*10 when compared with other groups. Higher KHN, μTBS, and DC (p=0.000001) values were observed for 3200*5 in comparison with the other groups. The 1400*5 (7 J/cm2) and 1400*10 (14 J/cm2) groups showed intermediate values (p=0.000001). Although similar results in terms of hardness, polymer cross-linking density and nanoleakage were observed when 5 seconds at 3200 mW/cm2 and 10 seconds at 1400 mW/cm2 groups were compared, the use of higher irradiance (3200 mW/cm2) for only 5 seconds showed better results in terms of bond strength and degree of conversion for both universal adhesives to dentin. The prolonged exposure time (10 seconds) at the higher irradiance (3200 mW/cm2) showed the worst results.

Addition of metal chlorides to a HOCl conditioner can enhance bond strength to smear layer deproteinized dentin

ObjectivesTo evaluate the effect of smear layer deproteinization using hypochlorous acid (HOCl) with/without metal chlorides (SrCl2 and ZnCl2) on the microtensile bond strength (µTBS) of two simplified adhesives to dentin. MethodsHuman dentin surfaces with a standardized smear layer were pretreated using a 105 ppm HOCl solution with/without SrCl2 (0.05 M, 0.1 M, 0.2 M, 0.4 M) or ZnCl2 (0.05 M, 0.1 M, 0.2 M) for 5 s, 15 s, or 30 s. After the deproteinizing solution was washed out with water for 5 s, 15 s, or 30 s, pretreated surfaces were bonded with one-step self-etch adhesive Bond Force II or universal adhesive Clearfil Universal Bond Quick, and µTBS was measured after 24 h. Additionally, the deproteinizing effects of HOCl solutions with/without the metal chlorides were compared by measuring changes in the amide:phosphate ratio using attenuated total reflection Fourier transform infrared spectroscopy. Statistical analysis was performed using multifactor ANOVA, Tukey’s post hoc tests and t-tests (p < 0.05). ResultsPretreatment with pure HOCl for 15 s and 30 s significantly decreased the amide:phosphate ratio (p < 0.05), indicating effective deproteinization, but the µTBS of both adhesives increased significantly only if HOCl was washed out for 30 s (p < 0.05). Increasing the concentrations of metal chlorides enabled shortening of the wash-out time down to 5 s while maintaining the improved µTBS (p < 0.05). The deproteinizing effect of HOCl was not significantly altered by the addition of metal chlorides (p > 0.05). SignificanceThe effectiveness of smear layer deproteinization using HOCl can be improved by the addition of metal chlorides, as their increasing concentration allowed to shorten the wash-out time from 30 s down to 5 s

Evaluation of multimode adhesion promoters with functional monomers without and with silica-coating for resin composite repair

This study aimed to investigate the effect of universal primers on resin composite repair with and without silica-coating while assessing adhesion durability under various aging methods. Specimens were fabricated using multiple increments of composite resin (Clearfil Majesty Esthetic) placed into cylindrical forms (diameter: 3.2 mm, height: 4 mm) and photopolymerized. Specimens (N = 300, n = 15 per group) were randomly assigned to three groups for aging (control: fresh-dry, 6 months water storage and thermocycling ×5000 cycles, 5–55 °C). These three main groups were further randomly assigned to two groups according to the surface conditioning procedures; (a) Control: No air-abrasion, and (b) Air abrasion with silica-coating (Co-Jet, 30 µm, 5 s, 2.5 bar). All subgroups were then randomly divided into five subgroups to be treated with adhesion promoters (a) All Bond Universal: AB (Bisco), (b) Clearfil Universal Bond Quick: SKB (Kuraray), (c) Monobond Plus: MP (Ivoclar Vivadent), (d) G-Premio Bond: GP (GC), (e) Clearfil Universal Bond: CU (Kuraray). After bonding according to the manufacturer’s instructions to new composite blocks, shear bond strength tests were conducted using a Universal testing machine (1 mm/min). Obtained Data (MPa) were analyzed by 3-way ANOVA and Tukey`s post-hoc tests (alpha = 0.05). Bond strength results were significantly affected by the adhesive type (p < 0.05), silica-coating (p < 0.05), and aging (p < 0.001) but the interaction terms were not significant (p > 0.05). In non-aged groups (24 h), no significant effect on bond strength was observed using silica-coating (min; 8.41; max:12.98) but after 6 months, silica-coating increased the results for AB, GP, and CU ranging between 9.56 and 11.25 (p < 0.05) and even more after thermocycling for SKB, MP, GP, CU (10.23–13.95) (p < 0.05) compared to non-conditioned groups (6.83–10.37 for 6 months, 8.96–11.18 for thermocycling, respectively). Failure types were mainly adhesive for non-air abraded groups but exclusively cohesive after silica-coating. For immediate or short-term resin composite repairs, silica-coating may not improve adhesion but shear bond strength could be secured by this conditioning method after aging.

Smear layer deproteinization with NaOCl and HOCl: Do application/wash-out times affect dentin bonding of one-step self-etch adhesives?

This study investigated the influence of application/wash-out times of sodium hypochlorite (NaOCl) and hypochlorous acid (HOCl) on dentin bond strength of one-step self-etch adhesives (1-SEAs). Human coronal dentin discs with a standardized smear layer were pretreated with 6% NaOCl or 100 ppm HOCl for 5 s, 15 s, or 30 s, and washed out with water for 5 s, 15 s or 30 s with or without the application of Clearfil DC Activator (CDA). No pretreatment was used as a control. The discs were bonded with a 1-SEA (Bond Force II or Clearfil Universal Bond Quick) and microtensile bond strength (µTBS) was measured after 24 h. Pretreatment with NaOCl for 15 s and 30 s significantly decreased µTBS (p<0.05), irrespective of wash-out time. The application of CDA recovered µTBS but did not outperform the control group. Conversely, pretreatment with HOCl for 15 s and 30 s followed by 30 s wash-out time significantly increased µTBS of 1-SEAs (p<0.05), regardless of CDA application.

Repairability of aged dimethacrylate-free ORMOCER-based dental composite resins with different surface roughening methods and intermediate materials

Statement of problemThe repair of damaged composite resin restorations has been recommended as a conservative treatment option. However, a reliable protocol for repairing ORMOCER-based restorations is lacking. PurposeThe purpose of this in vitro study was to investigate the effect of different surface roughening methods, repair composite resins, and intermediate materials on the repair bond strength of a dimethacrylate-free ORMOCER-based composite resin. Material and methodsCylindrical composite resin specimens (Admira Fusion) were roughened by using hydrofluoric acid (HF) or a diamond rotary instrument. In both groups, 4 types of intermediate materials were used (Monobond-S, Clearfil SE bond [second bottle], Clearfil Universal bond, GC Composite Primer), and then half of the specimens were repaired with a similar composite resin, and the other half with dimethacrylate composite resin (Clearfil-APX). The specimens (n=20) were then subjected to repair bond strength and failure mode evaluation. The data were analyzed by using the Weibull test, 3-way and 1-way ANOVA, and the Tukey honestly significant difference (HSD) test (α=.05). ResultsAll variables, including the surface roughening method, intermediate material, and repair composite resin, had a significant effect on repair bond strength (P<.001). The lowest repair bond strength values were obtained in the group roughened with HF, prepared with Monobond-S, and repaired with Admira Fusion, and the highest values were obtained in the group roughened with a rotary instrument, prepared with GC Composite Primer, and repaired with Clearfil APX (P<.05). All experimental groups had a lower bond strength than the cohesive and control groups (P<.05). In all experimental groups, the predominant failure modes were adhesive and mixed. ConclusionsThe use of a diamond rotary instrument was a more reliable method of creating roughness, and different intermediate materials based on the clinical situation can be used to repair dimethacrylate-free ORMOCER-based composite resin with similar or different composite resins. However, in general, the highest repair bond strengths were achieved with Clearfil APX-repaired specimens.

Application of Sulfinate Agent in Conjunction with HOCl Smear-Layer Deproteinization Improves Dentin Bonding Durability of One-step Self-etch Adhesives.

To evaluate the effect of a sulfinate agent on the bonding durability of one-step self-etch adhesives (1-SEAs) to smear-layer-covered dentin deproteinized with hypochlorous acid (HOCl). Human coronal dentin disks with a standardized smear layer were deproteinized with 100 ppm HOCl solution for 0 s (control), 15 s or 30 s. After rinsing with water for 30 s and air drying, half of the specimens were treated with a sulfinate agent (Scotchbond Universal Dual Cure Activator; SDA) prior to the application of a 1-SEA (Bond Force II [Tokuyama Dental] or Clearfil Universal Bond Quick [Kuraray Noritake]). Microtensile bond strength (µTBS) was measured after 24 h or 10,000 thermal cycles (TC). The data were analyzed by three-way ANOVA with Tukey's post-hoc tests and t-tests at the 0.05 significance level. The 24-h µTBS of both adhesives increased statistically significantly with the HOCl pretreatment for 15 s or 30 s (p < 0.05), but it was not statistically significantly affected by the application of SDA (p > 0.05). However, after TC, the groups treated with the combination of HOCl and SDA maintained their µTBS (p > 0.05), as opposed to untreated dentin and dentin treated with either HOCl or SDA, whose µTBS decreased significantly (p < 0.05). The application of the sulfinate agent did not statistically significantly affect the immediate bond strength of 1-SEAs, and it could not prevent a significant decrease in the bond strength to untreated dentin after thermocycling. However, the sulfinate agent significantly improved the bonding durability of 1-SEAs to HOCl smear-layer deproteinized dentin.

In vitro biological and adhesive properties of universal adhesive systems on sound and caries-affected dentine: 18 months

The present study aims to evaluate antimicrobial activity, cytotoxicity, as well as resin-dentine microtensile bond strength, nanoleakage and degree of conversion of six universal adhesives, on sound and caries-affected dentine after 18 months. The adhesives Prime&Bond Active (PBA), Scotchbond Universal (SBU), Tetric N-Bond Universal (TNU), Ambar Universal (AMU), Clearfil Universal Bond Quick (CUQ) and One Coat 7 Universal (OCU) were used. Antimicrobial activity was evaluated against Streptococcus mutans. For cytotoxicity, methyltetrazolium assay was used, after 24 h exposure of osteoblast-like cells line to the adhesive's dilution of 1, 0.1, and 0.01 v/v%. After, the adhesives were applied in etch-and-rinse or self-etch strategies on sound or caries-affected dentine surfaces, resin composites restorations were constructed. Then, the specimens were sectioned to obtain sticks to be evaluated in microtensile bond strength and nanoleakage after 24 h and 18 months, and degree of conversion after 24 h. ANOVA and Tukey's test were applied (α = 0.05). For antimicrobial activity, CUQ showed higher values than all adhesives. For cytotoxicity, the PBA, AMU, CUQ and OCU adhesives presented cytotoxicity in different dilutions. For microtensile bond strength, OCU presented the lowest values, regardless of time, dentine or strategy. For nanoleakage, differences were observed among adhesives depending on time, dentine or strategy. For degree of conversion, TNU presented the highest values, while PBA and OCU presented the lowest values. Worst values of microtensile bond strength and nanoleakage were always obtained in caries-affected dentine after 18 months. Thus, not all universal adhesives behave the same in terms of antimicrobial activity and cytotoxicity. However, the majority showed worst results when applied in caries-affected dentine, mainly after 18 months. Clinical relevance. Universal adhesive systems may have differences in their biological and adhesive properties, both on sound, but mainly in caries-affected dentine after 18 months.

Clinical Performance of Direct Composite Restorations in Patients with Amelogenesis Imperfecta - Anterior Restorations.

To evaluate the clinical performance of direct composite restorations using nanohybrid and nanofill composite materials in anterior teeth in patients with amelogenesis imperfecta (AI). The study included 15 patients with AI aged 14-30 years. During the study, the patients received anterior direct composite laminate veneer restorations using either a nanohybrid (Clearfil Majesty ES-2 and Clearfil Universal Bond, Kuraray Noritake) or a nanofill resin composite (Filtek Ultimate Universal Restorative and Single Bond Universal Adhesive, 3M Oral Care). The restorations were evaluated according to the modified USPHS criteria at baseline and at 1-, 2-, 3- and 4-year follow-up periods. The cumulative success rate of anterior restorations was 80.5% for nanohybrid and 92.5% for nanofill composite after 4 years. Eight restorations with nanohybrid and three restorations with nanofill resin composites failed. Ten restorations failed due to fracture; the fracture rate was 12.3%. Statistically significant differences were found between nanohybrid and nanofill composites regarding marginal discoloration and surface texture after 3 years. Furthermore, statistically significant differences were observed with respect to color match after 4 years. The use of a nanohybrid or nanofill composite for anterior direct restorations in patients with AI was observed to be satisfactory, based on the rate of ideal and clinically acceptable restorations. The primary reason for restoration failure was fracture. The failure rate of nanohybrid composite restorations was higher than with nanofill composite restorations with respect to survival and marginal adaptation criteria.

Which concentrations and application methods of chlorhexidine are proper for universal adhesives?

To in vitro evaluate the effects of different chlorhexidine (CHX) concentrations and application methods on the microshear bond strength (µSBS) between dentin and universal adhesives (UAs) used in self-etch mode with different functional monomers. In this study, 300 third molars were randomly assigned into 25 experimental groups based on the combinations of different variables: the UAs and functional monomers (Clearfil Universal Bond Quick [MDP, CU, Kuraray], Tokuyama Universal Bond [3D-SR, TU, Tokuyama], Gluma Bond Universal [MDP-4-META, GU, Kulzer], Prime & Bond Elect [MDP-PENTA, PEU, Dentsply Sirona], and Single Bond Universal [MDP-Vitrebond copolymer, SU, 3 M]), the CHX concentration (2% and 0.2%), and the application mode (with rinsing [R], without rinsing [WR]). Two composite resin samples were prepared on each tooth for the study groups (n = 24). Then, these samples were submitted to a µSBS test after 500 thermal cycles (load of 50 kgF and crosshead speed, 0.5 mm/min). The resulting data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney U tests (α = 0.05). The CU-2%CHX-WR, TU-2%CHX-WR, and GU-2%CHX-WR groups had lower µSBS values than the control groups (CU-control, TU-control, and GU-control) (p < 0.05). Using 2% CHX-WR may reduce the SBS of UAs when they were used in self-etch mode. On the other hand, 0.2% CHX can be used with or without rinsing, since this concentration did not affect the μSBS of any UA in self-etch mode, regardless of the functional monomer. When chlorhexidine is used with proper concentrations and application methods, it will not negatively affect the adhesion of a UA to dentin, even if the UA is used in self-etch mode.

Compressive strength, surface roughness, and surface microhardness of principle tricalcium silicate-based endodontic cements after universal adhesive application.

It was aimed to evaluate compressive strength (CS), surface roughness, and microhardness of mineral trioxide aggregate (ProRoot MTA) and Biodentine (BD) after adhesive application. Tests was carried out according to international ISO standard. ProRoot MTA and BD were prepared in Teflon molds according to manufacturer's instructions: n = 210 for CS; n = 210 for microhardness. Samples were incubated for 7 days at 37°C in 100% humidity. Surfaces were smoothed with up to 2000 grits of silicon-carbide sandpaper on abrasive device at 150 rpm, randomly divided into seven groups (n = 15). Clearfil Universal Bond, All Bond Universal, and Single Bond Universal (SBU) were applied in both total-etch and self-etch (SE) modes. Adhesives were applied according to manufacturers' recommendations (no adhesive used in control). CS was performed at speed of 1 mm/min, microhardness at 100 gr for 15 s. The surface roughness of the samples was analyzed with atomic force microscopy. Two-way analysis of variance and post hoc Tukey tests were used for the evaluation of the data. Man CS and microhardness values between ProRoot MTA and BD were as follows: 24.9 N, 72.6 HV; 59.8 N, 59.0 HV, respectively. In CS, BD was higher than ProRoot MTA (P < 0.05). In other comparisons except for SBU SE group (P < 0.05), BD and ProRoot MTA showed similar results (P > 0.05). However, ProRoot MTA was found higher than BD regarding microhardness (P < 0.05). As a result of the adhesive application in both BD and ProRoot MTA groups, a decrease in surface roughness was observed compared to the control group. BD exhibited better results than ProRoot MTA regarding CS. However, ProRoot MTA was found to be more successful than BD in terms of microhardness. BD and ProRoot MTA showed similar physical properties in terms of surface roughness. To improve regenerative procedures, besides the selection of bioceramic cements, the interaction between cements and materials applied during coronal restoration should be considered.

Bonding performance and ultramorphology of the resin-dentine interface of contemporary universal adhesives.

This study aimed at evaluating the microtensile bond strength (μTBS) and the resin-dentine ultramorphology (24h and 10months ageing) of contemporary universal adhesives applied in self-etch (SE) or etch-and-rinse (ER) mode. Sixty-four sound human molars were collected and randomly allocated in 4 main experimental groups (n = 16) according to the adhesive system employed and subsequently divided into two subgroups depending on their application mode SE or ER (n = 8): ZipBond X (ZBX-SE; ZBX-ER), Prime and Bond Active (PBA-SE; PBA-ER), Clearfil Universal Bond Quick (CBQ-SE; CBQ-ER) or Scotchbond Universal (SCH-SE; SCH-ER). The specimens were cut into sticks with a cross-sectional area of approximately 0.9 mm2 and subjected to μTBS testing at 24h or after 10months of ageing in artificial saliva (AS). Five representative fractured specimens from each group were analysed using field-emission scanning electron microscopy (FE-SEM). Resin-dentine slabs (Ø 0.9mm2) from each experimental group were immersed in Rhodamine B and subsequently analysed using confocal microscopy analysis (CLSM). The μTBS results were analysed using a two-way ANOVA and Newman-Keuls multiple-comparison test (α = 0.05). ZBX, PBA and SCH exhibited greater μTBS values than CQB at 24h in both SE and ER modes (p < 0.05). CQB showed a significant decrease in μTBS values after ageing both when used in SE and ER mode (p < 0.05). ZBX-ER exhibited no significant differences in the μTBS test after ageing (p > 0.05), while a significant drop in μTBS was seen in SCH-ER and APB-ER after 10-month ageing (p < 0.05). Clear signs of degradation were evident in the resin-dentine interface created with CQB regardless of the application mode or the ageing time. In APB-ER and SCH-ER groups, such signs of degradation were evident after ageing in AS. ZBX showed slight dye infiltration both when used in ER and SE mode. The long-term bonding performance of modern universal adhesives is usually influenced by the adhesive strategy employed; self-etching application should be prioritised during dentine bonding. Moreover, the use of shortened bonding protocols may compromise the quality of the resin-dentine interface and the bonding performance of most modern universal adhesives. The use of etch-and-rinse bonding procedures, as well as "shortened" application protocols should be eluded when using modern universal adhesives in dentine. However, new generation universal adhesives based on innovative chemical formulations may probably allow clinicians to achieve long-term bonding performance with such simplified system also when employed in ER mode.

Microtensile bond strength of glass ionomer cements to a resin composite using universal bonding agents with and without acid etching

ObjectivesTo assess the effect of two universal bonding agents on the microtensile bond strength (μTBS) of encapsulated conventional glass ionomers (CGICs) and resin-modified glass ionomers (RMGICs) to a resin composite, with or without the use of 35% phosphoric acid. MethodsFour materials were used in this study: Riva Self-cure and Riva Light-cure; SDI and Equia Forte Fil and Fuji II LC; GC. The specimens were prepared in Teflon moulds with half the specimens for each GIC etched using 35% phosphoric acid (Ultra-Etch) and the remainder not etched. Each group was randomly subdivided into three groups, where the first two groups received an air-thin layer of bonding agent (G-Premio Bond = GPB or Clearfil Universal Bond = CUB) then light cured; and the third group had no bonding agent. For all groups, a nanohybrid composite (GC Kalore; GC) was placed incrementally on the GIC. Following 24 h immersion in distilled water, each block was embedded in epoxy resin in a cubic mould and sectioned by a cutting device. The stick specimens were then subjected to μTBS testing. ResultsThe application of both universal bonding agents significantly enhanced the μTBS of all GICs (p < 0.001). Both RMGICs exhibited higher μTBS compared to that of CGICs (p < 0.001). The application of universal bonding agents with acid etching significantly increased the μTBS of both CGICs and RMGICs to resin composite in contrast to without acid etching. ConclusionUsing 35% phosphoric acid for 15 s prior to the application of universal bonding agents improved the μTBS of GIC to resin composite. Clinical significanceUsing Universal bonding agents with 15 s acid etching may increase the bond strength of both CGICs and RMGICs to resin composite when utilising the sandwich technique.

In Vitro Performance of Different Universal Adhesive Systems on Several CAD/CAM Restorative Materials After Thermal Aging.

To evaluate the microshear bond strength (mSBS) of 10 universal adhesive systems applied on five different CAD/CAM restorative materials, immediately and after thermal aging. Five CAD/CAM materials were selected: 1) feldspathic glass ceramic (FeCe); 2) pre-polymerized reinforced resin composite (ReRC); 3) leucite-reinforced glass ceramic (LeGC); 4) lithium disilicate (LiDi); and 5) yttrium-stabilized zirconium dioxide (ZiDi). For each material, 15 blocks were cut into four rectangular sections (6 × 6 × 6 mm; n=60 per group) and processed as recommended by the respective manufacturer. For each indirect material, the following adhesive systems were applied according to the respective manufacturer's instructions: 1) AdheSE Universal [ADU]; 2) All-Bond Universal [ABU]; 3) Ambar Universal [AMB]; 4) Clearfil Universal Bond [CFU]; 5) Futurabond U [FBU]; 6) One Coat 7 Universal [OCU]; 7) Peak Universal Bond [PUB]; 8) Prime&Bond Elect [PBE]; 9) Scotchbond Universal Adhesive [SBU]; 10) Xeno Select [XEN, negative control]. After the application of the adhesive system, cylinder-shaped transparent matrices were filled with a dual-curing resin cement (NX3) and light cured. Specimens were tested in shear mode at 1.0 mm/min (mSBS), after 24 hours and 10,000 thermal cycles (TC). All data were submitted to statistical analysis (α=0.05). For FeCe, there was no significant decrease in mean mSBS for AMB, FBU, and SBU after TC when compared at 24 hours. For ReRC, AMB and SBU showed higher mean mSBS when compared to CFU and XEN, after 24 hours and TC. For LiDi, FBU and OCU showed higher mean mSBS when compared to CFU and XEN, after 24 hours and TC. For LeGC, AMB and PUB showed higher mean mSBS when compared to XEN, after 24 hours and TC. For ZiDi, OCU and SBU showed higher mean mSBS when compared to XEN, after 24 hours and TC. In addition, PBE and XEN showed the lowest mean mSBS after TC with higher percentage of bond strength reduction. The mean mSBS among the different universal adhesives varied widely for each CAD/CAM material used. In addition, most universal adhesives underwent a statistically significant bond strength reduction after TC.

53 - Use of EDTA on Bond of Adhesives to Fluorotic Enamel

To compare the effect of active pre-conditioning with 17% ethylenediaminetetraacetic acid (EDTA) vs. 37% phosphoric acid (PA) on the resin-enamel microshear bond strength (μSBS), enamel-etching pattern, and in-situ degree of conversion (in-situ DC) of four universal adhesive systems on sound enamel and fluorotic enamel. 224 extracted human molars (112 with no fluorosis and 112 with fluorosis) were sectioned into 4 parts and divided into 16 experimental groups based on the enamel surface (sound or fluorotic enamel), adhesive system (Clearfil Universal Bond [CUB], Futurabond U [FBU], iBond Universal [IBU], or Scotchbond Universal [SBU]), and enamel conditioning agent (phosphoric acid [PA] mode or EDTA mode). The specimens were stored for 24 h and tested under shear stress at 1.0 mm/min (μSBS). The adhesive-enamel interfaces were evaluated for in situ DC using micro-Raman spectroscopy. The enamel-etching pattern was evaluated using a scanning electron microscope. The SBS and in situ DC data were analyzed separately using three-way analysis of variance and Tukeys post-hoc test (α = 0.05). Sound enamel showed higher μSBS and DC values as compared to fluorotic enamel (p < 0.05). However, no significant difference was observed for μSBS, DC (p > 0.05), and etching patterns when the PA and EDTA modes were compared in sound and fluorotic enamel. Moreover, CUB and SBU showed higher mean values of μSBS than that of FBU and IBU in both sound and fluorotic enamel (p < 0.05). As compared to PA, active pre-conditioning with EDTA showed similar μSBS values and enamel etching patterns for all the adhesive systems in fluorotic enamel, without compromising the in situ DC.

Does the bonding effectiveness of a fiber post/resin composite benefit from mechanical or chemical treatment? Seven methods for saliva-contaminated surfaces.

This study examined four cleaning methods and three chemical treatments for artificial saliva-contaminated fiber posts in terms of bonding durability to resin composite core materials. Non-contaminated fiber posts (Tokuyama FR Post, Tokuyama Dental) and those contaminated (GC Fiber Post, GC) with artificial saliva (Saliveht Aerosol, Teijin Pharma) were used. Washing and drying (WD), alcohol cleaning (AlC), H3PO4 etching (P/WD), alumina blasting (B/D) for decontamination and silanization (Clearfil Ceramic Primer Plus, Kuraray Noritake Dental, Si), resin priming (HC Primer, Shofu, MMA), and bonding resin application (Clearfil Universal Bond Quick, Kuraray Noritake Dental, BR) for chemical treatment were performed. The treated fiber post was planted inside a cylindrical tube and filled with resin composite (DC Core Automix ONE, Kuraray Noritake Dental). The specimen was sectioned, and a push-out test was performed after 24 h, 1 month, and 3 months. The fracture surface was observed using a scanning electron microscope (SEM). Adhesion between the non-contaminated fiber post and resin composite did not improve by silanization and decreased by alumina blasting. SEM observations revealed a fractured glass fiber by alumina blasting. Saliva contamination decreased the bond strength between the fiber post and resin composite; however, recovery was achieved by WD, Alc, P/WD, and B/D. Compared to Si, BR (P = 0.009) was effective in restraining the long-term durability of bonding, whereas MMA (P = 0.99) was not. The application of bonding resin after alcohol cleaning is the most convenient and effective clinical procedure for fiber post surface treatment.

1 - 18-Month Clinical Evaluation of Universal Adhesive Applied in No-Waiting Technique

To evaluate the clinical behavior of a universal adhesive applied in the no-waiting technique in non-carious cervical lesions (NCCLs). Forty-four patients participated in this study. One hundred and seventy-six restorations were assigned to four groups according to the adhesive system in the conditioning strategies and in the waiting time: Prime&Bond Active (PB), applied in the etch-and-rinse strategy (ER) and self-etch (SE) with 20 s application and Clearfil Universal Bond Quick (CQ), applied in the ER and SE strategy), in no-waiting technique. One experienced and calibrated operator made the restorations with (Filtek Z-350 XT) composite resin using the incremental technique. The restorations were evaluated at baseline and after 18 months using both the World Dental Federation (FDI) and the United States Public Health Service (USPHS) criteria. Statistical analyses were performed with Friedman repeated measures analysis of variance by rank and McNemar test for significance in each pair. Ten restorations (2 for PB-ER, 4 for PB-SE, and 4 for CQ-SE) were lost after 18 months. Had a retention rate of 95,45% for PB-ER, 90,9% for PB-SE, 90,9% for CQ-SE and 100% for CQ when using the ER adhesive strategy (p > 0.05 for either criterion). Seventeen restorations showed some discrepancies in marginal adaptation at the 18-month recall using the FDI criteria (2 for PB-ER, 2 for PB-SE, 4 for CQ-ER, and 9 for CQ-SE), but only three restorations were scored as bravo for marginal adaptation in the USPHS criteria (3 for CQ-SE; p > 0.05). The clinical performance of the CQ adhesive in the "no waiting" technique was similar to the PB adhesive in conventional application (20 s), promoting very satisfactory results when applied in the ER or SE strategy, after 18 months of clinical evaluation in non-carious cervical lesions.

O4 - Silane Containing Universal Adhesive/Cement for Bonding to Silica-Coated High-Translucent Zirconia

The aim of this study was to evaluate the bonding performance of high-translucent zirconia when pretreated with glass beads and the efficiency of silane contained in self-adhesive resin cement and universal adhesive as chemical treatment for silica-coated high-translucent zirconia. 240 fully sintered disk-shaped zirconia specimens (Y-PSZ, Zpex smile, Tosoh, Japan) were assigned to 4 groups according to mechanical surface pretreatment: alumina particles abrasion with 0.2 MPa pressure (AB2), tribochemical silica-coating with 0.2 MPa (TSC), and glass beads air-abrasion with 0.2 MPa (GB2) and 0.4 MPa (GB4). Each group was cemented with Panavia SA Universal (SAU), Rely X Ceramic Primer (3 M ESPE) + Panavia SA plus (Kuraray Noritake Dental) (S-SAP), and Clearfil Universal Bond Quick + SAP (U-SAP). Tensile bond strength (TBS) was measured at crosshead speed of 2 mm/min after 24 h or 10000 thermocycling (TC) followed by the failure modes analysis (n=10). Surface morphology and surface elemental composition of the abraded zirconia surface analyses were examined under SEM/EDS. Survival analysis was done for TBS data (p = 0.05). After TC, there was a significant decrease in bond strength all groups except TSC and GB4 treated with S-SAP. S-SAP showed highest TBS with TSC, GB2, and GB4. AB2 indicated the highest TBS with U-SAP. SAU showed higher TBS with GB4 compared to GB2. GB4 represented the highest Si content compared to TSC and GB2. Sailanization of glass beads air-abraded zirconia ceramic is mandatory step for successful adhesion to resin cement. Silane containing self-etch adhesive cement was more effective than universal adhesive for glass beads treated zirconia especially with higher air-pressure, but both are less efficient than pure silane treatment. While universal adhesive is efficient pretreatment on tribochemical silica-coating surface and the most effective on alumina-blasted zirconia ceramic.

The Effect of Radiotherapy on the Marginal Adaptation of Class II Direct Resin Composite Restorations: A Micro-computed Tomography Analysis.

This laboratory study was designed to evaluate the marginal adaptation of Class II mesio-occlusodistal (MOD) restorations at the cervical region with micro-computed tomography (micro-CT). Two groups of restorations were compared: 1) those that had been exposed to radiotherapy before restoration was performed using a universal adhesive in etch-and-rinse and self-etch modes; and 2) those that had previously been restored using a universal adhesive in etch-and-rinse and self-etch modes and had subsequently undergone radiotherapy. Sixty intact human molars were randomly divided into groups according to irradiation status: no radiotherapy (control group); radiotherapy followed by restoration (radiotherapy-first group); and restoration followed by radiotherapy (restoration-first group). These three groups were then subdivided into two groups each on the basis of adhesive application type (etch-and-rinse and self-etch modes), for a total of six groups (n=10/group). Standardized Class II MOD cavities were prepared. A universal adhesive (Clearfil Universal Bond Quick, Kuraray, Okayama, Japan) was applied. The teeth were restored with resin composite (Estelite Posterior Quick, Tokuyama, Tokyo, Japan). The radiotherapy protocol was conducted with 60 gray (Gy) at 2 Gy/day, five days a week for six weeks. Adhesive defects were analyzed in distal and mesial views and evaluated with micro-CT (SkyScan 1174v2, Kontich, Antwerp, Belgium) on the basis of the volume of black spaces between the cavity walls and the restorative materials (mm3). The data were analyzed using the Kruskal-Wallis, Mann Whitney U and Wilcoxon tests (p<0.05). The radiotherapy protocol did not affect the marginal adaptation of the universal adhesive at the cervical regions. Regarding the application modes, for the radiotherapy-first group, the self-etch mode caused significantly higher adhesive defects than the etch-and-rinse mode at the dentin margin. For the no-radiotherapy group, the adhesive defects at the dentin margin were significantly higher than at the enamel margin with the application of the etch-and-rinse mode.

Investigations of silane-MDP interaction in universal adhesives: A ToF-SIMS analysis

ObjectivesThe purposes of this study were to investigate whether the presence of silane in universal adhesives affects the functions of 10-methacryloyloxydecyl dihydrogen phosphate (MDP) and adhesion to zirconia. MethodsTwo silane-containing universal adhesives (Scotchbond Universal (SBU) and Clearfil Universal-Bond (CUB)) and two silane-free adhesives (All-Bond Universal (ABU) and SE-Bond primer (SE)) were individually applied on zirconia disks. Time-of-flight secondary-ion-mass-spectrometry (ToF-SIMS) examined the distributions of MDP- and silane-related ions, as well as evidence of zirconium phosphate (ZrP) compounds, on the surface and interfacial regions using a depth profiling mode. The hydrophilicity and resin wettability of the treated zirconia were examined using a contact angle test. For the shear bond strength (SBS) test, the zirconia disks were air-blasted, treated with the assigned adhesives, and bonded with pre-cured composite cylinders using a resin cement. These resin-zirconia assemblies received a bond test after 24-h storage. ResultsBoth SBU and CUB exhibited silane-related ions and ZrO2(OH)-, but fewer PO- ions in the interfacial regions. CUB had more siloxane-related ions. SE-treated zirconia had abundant PO- ions and particularly high PO3-- and ZrP- related ions in the interfacial regions. The silane-free adhesives exhibited a higher affinity to both water and adhesive liquids. SE showed significantly higher SBSs compared to ABU, while SBU and CUB were not statistically different. SignificanceThe silane content may cause hydroxylation of zirconia and affect MDP adsorption. An acidic pH accelerated the condensation of silanol. The bond performance of the MDP-based adhesive could be influenced by the silane content and other components.