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1.
Effect of thermocycling and water storage on bond longevity of two self-etch adhesives.
Khoroushi, M, Rafiei, E
General dentistry. 2013;(3):39-44
Abstract
Despite recent improvements in adhesive systems and their bond strength to enamel and dentin, the resin-tooth interface appears to be the weakest part of tooth-colored restorations; in addition, there are concerns regarding bond durability of self-etch adhesives (SEAs). This in vitro study investigated the bond durability of 2 such adhesives following thermocycling and water storage. Forty-eight intact human third molars were sectioned mesiodistally and mounted in acrylic resin so that buccal and lingual surfaces were positioned horizontally. All enamel and dentin surfaces were ground flat and polished on silicon carbide papers. Samples were separated into 2 groups (n = 24). A 1-step SEA was applied to one group, while a 2-step SEA was applied to the other, according to manufacturers' instructions. Half of the specimens in each group underwent shear bond strength (SBS) testing after 24 hours of incubation, while the other half were tested after 3000 thermal cycles and 6 months of water incubation. SBS data were analyzed using 2-way ANOVA, 1-way ANOVA, and a post hoc Tukey test at a significance level of 0.05. Under the limitations of the present study, the 2-step SEA demonstrated higher baselines and aged bond strength to dental tissues compared to the 1-step SEA; in addition, the enamel bond strength of the 2-step SEA improved after aging.
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2.
Immediate bonding properties of universal adhesives to dentine.
Muñoz, MA, Luque, I, Hass, V, Reis, A, Loguercio, AD, Bombarda, NH
Journal of dentistry. 2013;(5):404-11
Abstract
OBJECTIVES To evaluate the dentine microtensile bond strength (μTBS), nanoleakage (NL), degree of conversion (DC) within the hybrid layer for etch-and-rinse and self-etch strategies of universal simplified adhesive systems. METHODS forty caries free extracted third molars were divided into 8 groups for μTBS (n=5), according to the adhesive and etching strategy: Clearfil SE Bond [CSE] and Adper Single Bond 2 [SB], as controls; Peak Universal Adhesive System, self-etch [PkSe] and etch-and-rinse [PkEr]; Scotchbond Universal Adhesive, self-etch [ScSe] and etch-and-rinse [ScEr]; All Bond Universal, self-etch [AlSe] and etch-and-rinse [AlEr]. After restorations were constructed, specimens were stored in water (37°C/24h) and then resin-dentine sticks were prepared (0.8mm(2)). The sticks were tested under tension at 0.5mm/min. Some sticks from each tooth group were used for DC determination by micro-Raman spectroscopy or nanoleakage evaluation (NL). The pH for each solution was evaluated using a pH metre. Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). RESULTS For μTBS, only PkSe and PkEr were similar to the respective control groups (p>0.05). AlSe showed the lowest μTBS mean (p<0.05). For NL, ScEr, ScSe, AlSe, and AlEr showed the lowest NL similar to control groups (p<0.05). For DC, only ScSe showed lower DC than the other materials (p<0.05). CONCLUSIONS Performance of universal adhesives was shown to be material-dependent. The results indicate that this new category of universal adhesives used on dentine as either etch-and-rinse or self-etch strategies were inferior as regards at least one of the properties evaluated (μTBS, NL and DC) in comparison with the control adhesives (CSE for self-etch and SB for etch-and-rinse).
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3.
Effect of three different contamination removal methods on bond strength of a self-etching adhesive to dentin contaminated with an aluminum chloride hemostatic agent.
Ajami, AA, Kahnamoii, MA, Kimyai, S, Oskoee, SS, Pournaghi-Azar, F, Bahari, M, Firouzmandi, M
The journal of contemporary dental practice. 2013;(1):26-33
Abstract
AIM: This study evaluated the effect of three different contamination removal methods on bond strength of one-step self-etching adhesive to dentin contaminated with an aluminum chloride hemostatic agent. MATERIALS AND METHODS One hundred noncarious adult molars were used in this study; 2-mm-thick dentin disks were prepared and randomly assigned to 5 groups (n = 20). Group I: control; group II: hemostatic agent-contaminated; group III: hemostatic agent-contaminated and rinsing with water; group IV: hemostatic agent-contaminated and ethylene diamine tetraacetic acid (EDTA) application; and group V: hemostatic agent-contaminated and phosphoric acid application. Clearfil S3 Bond was used to bond composite to dentin surfaces. Subsequent to adding composite cylinders the shear bond strength test was performed. Data were analyzed by one-way ANOVA and Tukey test. Two additional specimens from each group were prepared and evaluated under scanning electron microscope (SEM). RESULTS There were statistically significant differences in bond strength among the groups (p < 0.001). In two-by-two comparisons statistically significant differences were observed in bond strength values between all the groups (p < 0.001) except for groups I and IV (p = 0.933). CONCLUSION Aluminum chloride hemostatic agent adversely affected the bond strength of self-etch adhesive to dentin. However, application of EDTA increased the bond strength to the level of normal dentin. CLINICAL SIGNIFICANCE EDTA and phosphoric acid removed aluminum chloride hemostatic agent contamination of dentin surfaces. However, unlike EDTA phosphoric acid failed to increase the bond strength of self-etch adhesive to dentin to the level of the control group.
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4.
Evaluation of effect of different cavity disinfectants on shear bond strength of composite resin to dentin using two-step self-etch and one-step self-etch bonding systems: a comparative in vitro study.
Reddy, MS, Mahesh, MC, Bhandary, S, Pramod, J, Shetty, A, Prashanth, MB
The journal of contemporary dental practice. 2013;(2):275-80
Abstract
AIM AND OBJECTIVES To evaluate the effect of 2% chlorhexidine, 2% sodium hypochlorite, 3% hydrogen peroxide on shear bond strength of composite resin to dentin using two-step and onestep self-etch bonding systems and to study the mode of failure of specimens under stereomicroscope. MATERIALS AND METHODS Eighty extracted sound human posterior teeth were used. The occlusal surfaces were ground to expose the dentin and were then randomly divided into 4 main groups. In group I, no cavity disinfectant was used and served as control. In groups II, III, IV, 2% chlorhexidine, 2% sodium hypochlorite and 3% hydrogen peroxide were used as cavity disinfectants respectively. Each group was then divided into two subgroups of 10 teeth each according to the bonding agent used, two-step self-etch (Adper SE Plus) and one-step self-etch (Adper Easy One) respectively. A transparent cylindrical plastic tube was loaded with microhybrid composite and placed over the dentin and light cured for 40 seconds. The specimens were subjected to shear stress in the universal testing machine. RESULTS Pretreatment with 2% chlorhexidine, 2% sodium hypochlorite and 3% hydrogen peroxide, had a negative effect on the shear bond strength of self-etching bonding systems. CONCLUSION The highest bond strength was found in 2% chlorhexidine group followed by 2% sodium hypochlorite group and the lowest bond strength was found in 3% hydrogen peroxide group. CLINICAL SIGNIFICANCE All three cavity disinfectants used in this study reduced the shear bond strength and hence should be used with caution.
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5.
Evaluation of micro-tensile bond strength of caries-affected human dentine after three different caries removal techniques.
Sirin Karaarslan, E, Yildiz, E, Cebe, MA, Yegin, Z, Ozturk, B
Journal of dentistry. 2012;(10):793-801
Abstract
OBJECTIVE This study evaluated the effect that different techniques for removing dental caries had on the strength of the microtensile bond to caries-affected human dentine created by three bonding agents. MATERIALS AND METHODS Forty-five human molar teeth containing carious lesions were randomly divided into three groups according to the technique that would be used to remove the caries: a conventional bur, an Er:YAG laser or a chemo-mechanical Carisolv(®) gel (n=15). Next, each of the three removal-technique groups was divided into three subgroups according to the bonding agents that would be used: Clearfil(®) SE Bond, G-Bond(®), or Adper(®) Single Bond 2 (n=5). Three 1mm(2) stick-shaped microtensile specimens from each tooth were prepared with a slow-speed diamond saw sectioning machine fitted with a diamond-rim blade (n=15 specimens). For each removal technique one dentine sample was analysed using scanning electron microscopy. RESULTS There were statistically significant differences in the resulting tensile strength of the bond among the techniques used to remove the caries and there were also statistically significant differences in the strength of the bond among the adhesive systems used. The etch-and-rinse adhesive system was the most affected by the technique used to remove the caries; of the three techniques tested, the chemo-mechanical removal technique worked best with the two-step self etch adhesive system. CONCLUSION The bond strength values of the etch-and-rinse adhesive system were affected by the caries removal techniques used in the present study. However, in the one- and two-step self etch adhesive systems, bond strength values were not affected by the caries removal techniques applied. While a chemo-mechanical caries removal technique, similar to Carisolv(®), may be suggested with self etch adhesive systems, in caries removal techniques with laser, etch-and-rinse systems might be preferred. CLINICAL SIGNIFICANCE Caries removal methods may lead to differences in the characteristics of dentine surface. Dentine ultra structure generally affects the bonding of adhesive materials commonly used in restorative dentistry. Whereas etch-and-rinse system, like the ones used in the present study, are affected by these changes, the self etch systems are not affected. Hence, clinicians may opt for caries removal methods and systems appropriate for each patient and practice.
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6.
Degree of conversion of two-step etch-and-rinse adhesives: In situ micro-Raman analysis.
Navarra, CO, Breschi, L, Turco, G, Diolosà, M, Fontanive, L, Manzoli, L, Di Lenarda, R, Cadenaro, M
Journal of dentistry. 2012;(9):711-7
Abstract
OBJECTIVES DC of three commercial two-step etch-and-rinse adhesives across the dentine-adhesive interface was investigated using micro-Raman spectroscopy. The hypothesis tested was that no difference in DC would exist among the adhesives tested. METHODS Adper Scotchbond 1XT (3M ESPE), Prime&Bond NT (Dentsply DeTrey), and Ambar (FGM) were applied on human dentine disks (n=9). Composite increments of 2mm were then applied on the adhesive surface. Raman spectra were collected along the dentine-adhesive interface. The relative intensities of the peaks associated with the mineral (PO(4)(3-) at 960cm(-1)) and the adhesive (CC at 1640cm(-1); phenyl CC at 1610cm(-1)) were used to identify the adhesive within the hybrid layer and calculate its DC. RESULTS Adper Scotchbond 1XT and Ambar showed similar DC (79±7% and 77±7%, respectively), while a lower DC was found for Prime&Bond NT (70±7%; p<0.05). CONCLUSIONS The hypothesis tested was rejected because differences were found among the adhesives tested. The difference in DC among the three adhesive systems can be attributed to different monomer compositions and solvents. Further studies are needed to correlate DC with other mechanical properties of these adhesives. CLINICAL SIGNIFICANCE Insufficient polymerization of an adhesive can result in a weak hybrid layer, and the presence of unreacted monomers may result in degradation of the polymeric network, decreasing the strength and longevity of the bond. In the present study, Adper Scotchbond 1XT and Ambar performed significantly better than Prime&Bond NT.
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7.
Hydrolytic degradation of the resin-dentine interface induced by the simulated pulpal pressure, direct and indirect water ageing.
Feitosa, VP, Leme, AA, Sauro, S, Correr-Sobrinho, L, Watson, TF, Sinhoreti, MA, Correr, AB
Journal of dentistry. 2012;(12):1134-43
Abstract
OBJECTIVES The aim of this study was to compare the hydrolytic effects induced by simulated pulpal pressure, direct or indirect water exposure within the resin-dentine interfaces created with three "simplified" resin bonding systems (RBSs). METHODS A two-step/self-etching (CSE: Clearfil SE Bond), one-step/self-etching (S3: Clearfil S3) and etch-and-rinse/self-priming (SB: Single-bond 2) adhesives were applied onto dentine and submitted to three different prolonged (6 or 12 months) ageing strategies: (i) Simulated Pulpal Pressure (SPP); (ii) Indirect Water Exposure (IWE: intact bonded-teeth); (iii) Direct Water Exposure (DWE: resin-dentine sticks). Control and aged specimens were submitted to microtensile bond strength (μTBS) and nanoleakage evaluation. Water sorption (WS) survey was also performed on resin disks. Results were analysed with two-way ANOVA and Tukey's test (p < 0.05). RESULTS The μTBS of CS3 and SB dropped significantly (p < 0.05) after 6 months of SPP and DWE. CSE showed a significant μTBS reduction only after 12 months of DWE (p = 0.038). IWE promoted no statistical change in μTBS (p > 0.05) and no evident change in nanoleakage. Conversely, SPP induced a clear formation of "water-trees" in CS3 and SB. WS outcomes were CS3 > SB = CSE. CONCLUSION The hydrolytic degradation of resin-dentine interfaces depend upon the type of the in vitro ageing strategy employed in the experimental design. Direct water exposure remains the quickest method to age the resin-dentine bonds. However, the use of SPP may better simulate the in vivo scenario. However, the application of a separate hydrophobic solvent-free adhesive layer may reduce the hydrolytic degradation and increase the longevity of resin-dentine interfaces created with simplified adhesives.
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8.
Effect of waiting interval on chemical activation mode of dual-cure one-step self-etching adhesives on bonding to root canal dentin.
Thitthaweerat, S, Nakajima, M, Foxton, RM, Tagami, J
Journal of dentistry. 2012;(12):1109-18
Abstract
OBJECTIVES The purpose of this study was to evaluate the effect of waiting interval on the chemical activation of dual-cure one-step self-etching adhesives before placing resin core materials on the regional bond strength to root canal dentin. MATERIALS AND METHODS Forty-eight post spaces prepared in human lower premolars were applied with four dual-cure one-step self-etching adhesives Estelite Core Quick: ECB/ECQ, Clearfil DC Core Automix: CDB/CDC, Unifil Core EM: UNB/UNC, BeautiCore: BTB/BTC as the manufacturers' instructions. These adhesives were cured with light activation for 10 s, or chemical activation with 0, 10, and 30 s waiting intervals prior to placing resin core material. Resin core materials were then placed into the post space and light-cured for 60 s. After 24h water storage, each specimen was serially sliced into 8, 0.6 mm × 0.6 mm thick beams for the μTBS test. The regional μTBS data were analyzed using three-way ANOVA and Dunnett's T3 test (p < 0.05). RESULTS For the chemical activation with 10 and 30 s waiting intervals, ECB and CDB exhibited significantly improved μTBS, whereas for UNB and BTB, the μTBS were not significantly different but increased with waiting interval. On the other hand, light-activation of all the adhesives produced significantly higher μTBS to root canal dentin than chemical activation (p < 0.05), except for the UNB group. CONCLUSIONS For the chemical activation of dual-cure one-step self-etching adhesives, a waiting interval prior to placing resin core material improved μTBS to root canal dentin. Polymerising the adhesives before polymerisation reaction of resin core material would be effective for bonding to root canal dentin. CLINICAL RELEVANCE For chemical activation mode as well as light activation mode, pre-curing of adhesive layer before proceeding polymerisation of resin filling material would produce higher bonding performance to dentin in the cavity.
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9.
Bond strength of HEMA-containing versus HEMA-free self-etch adhesive systems to dentin.
Felizardo, KR, Lemos, LV, de Carvalho, RV, Gonini Junior, A, Lopes, MB, Moura, SK
Brazilian dental journal. 2011;(6):468-72
Abstract
This study analyzed the bond strength (BS) of HEMA versus HEMA-free self-etch adhesive systems to dentin. The occlusal surface of 20 third molars was removed and the dentin was abraded with 600-grit silicon carbide paper. The teeth were randomly assigned to 4 groups (n = 5) and restored with GO, Adper SE Plus, OptiBond All-In-One, and Clearfil 3S Bond adhesive systems and Filtek Z350 composite. After light curing (600 mW/cm²), the teeth were stored in distilled water at 37 ºC for 24 h and were sectioned in the mesiodistal and buccolingual directions to obtain sticks (0.8 mm²). The sticks were subjected to tensile force using a universal testing machine (0.5 mm/min), and the modes of failure were analyzed by scanning electron microscopy and classified as adhesive, cohesive, or mixed. The BS data (in MPa) were treated using one-way ANOVA and Tukey's tests at 5% significance. GO presented the lowest mean bond strength value (10.57 ± 3.72) and differed significantly from the other materials (p = 0.001), which, in turn, presented statistically similar results (p>0.05) among themselves: Adper SE Plus (29.08 ± 8.93), OptiBond All-In-One (28.36 ± 6.49), and Clearfil 3S Bond (28.62 ± 6.97). Mixed fractures were the most prevalent. It was concluded that the influence of HEMA on BS to dentin was material dependent.
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10.
Bonding ability of three ethanol-based adhesives after thermal fatigue.
Perdigão, J, Gomes, G, Sezinando, A
American journal of dentistry. 2011;(3):159-64
Abstract
PURPOSE To study the effect of thermal fatigue on the microTBS and interfacial morphology of three ethanol-based etch-&-rinse 2-bottle adhesives. METHODS microTBS - 24 third molars were randomly assigned to one of three adhesive systems: (1) Adper Single Bond Plus (SBP, 3M ESPE); (2) Ambar (AMB, FGM); (3) Excite (EXC, Ivoclar Vivadent), and restored with a hybrid resin composite. For each adhesive, half of the specimens were thermocycled (TC) for 20,000 cycles (5-55 degrees C) while the other half was kept in distilled water for 24 hours at 37 degreesC (control). Specimens were sectioned in X and Y directions and the resulting sticks were tested to failure in tension mode at a crosshead speed of 1 mm/minute. Statistical analysis was computed using ANOVA and Tukey's post hoc for the microTBS; and non-parametric cross-tabulation with Chi-Square for the pre-testing failures at P< 0.05. Interfacial morphology -The occlusal enamel was removed from 12 extracted molars perpendicular to the long axis of the tooth. Teeth were equally assigned to one of the three adhesives and restored with a 1 mm-thick layer of a hybrid composite resin. A 2 mm-thick disk was sectioned from each specimen and cross-sectioned in two identical halves. Half of the each specimen was TC for 20,000 cycles (5-55 degrees C) while the other half was kept in distilled water for 24 hours at 37 degrees C (control). Specimens were chemically challenged and prepared for FESEM observation to observe the integrity of the hybrid layer before and after thermal fatigue. Micrographs were recorded digitally at standard magnifications and measurements were taken with the microscope embedded image software. RESULTS microTBS - SBP and AMB resulted in statistically similar mean microTBS regardless of thermal fatigue. EXC resulted in statistically lower mean microTBS than SBP and AMB for the control (P< 0.001) and for the TC specimens (P< 0.0001). Interfacial morphology - The hybrid layers of SBP and AMB were densely infiltrated without interfacial failure. For EXC, extensive areas of debonding were observed between the adhesive layer and the hybrid layer both for the control and the TC groups. Thermal fatigue did not influence the bonding ability of AMB and SBP, but was detrimental for EXC.