Microtensile Bond Strength Research Articles

Effect of sodium hypochlorite on bonding performance of universal adhesives to pulp chamber dentin

Abstract Background/purpose The most widely utilized irrigation solution in endodontic therapy is sodium hypochlorite (NaOCl). The purpose of this study was to assess the effects of NaOCl on the bond strength of four universal adhesives and one two-step self-etch adhesive to pulp chamber dentin. One hundred sixteen extracted sound human third molars were used in this study. All the teeth were divided into two groups: (1) with NaOCl treatment and (2) without NaOCl treatment. These two groups were subdivided into five bonding groups: G-Premio Bond (GP), Beautibond Xtreme (BBX), Scotchbond Universal (SBU), Clearfil Universal Bond Quick (UBQ), and Clearfil Megabond 2 (MB2). The microtensile bond strength (μTBS), the fracture mode analysis, resin-dentin interface and dentin surface were observed by SEM. Two-way ANOVA was performed to analyze the μTBS (α = 0.05). The μTBS of the NaOCl group significantly decreased for GP and MB2 ( P < 0.05). Significant effects of adhesive (F = 12.182, P < 0.001), and irrigation (F = 27.224, P < 0.001) on the μTBS were observed, whereas interaction between adhesive and irrigation was not significant (F = 1.761, P = 0.144). The adhesive layer with variable thickness was observed in all groups with different morphological structures. The effect of NaOCl treatment on the μTBS differs depending on the type of adhesives.

Influence of silver nanoparticles on the resin-dentin bond strength and antibacterial activity of a self-etch adhesive system

Statement of problemThe influence of silver nanoparticles on adhesive properties of Single Bond Universal (3M ESPE) and the antibacterial activity of silver nanoparticles-modified adhesives against Streptococcus mutans is unclear. PurposeThe purpose of this in vitro study was to evaluate the effect of silver nanoparticles on the dentin bond strength of modified adhesives and the antibacterial activity against the cariogenic pathogen S. mutans. Material and methodsSingle Bond Universal adhesive was used as the control. Silver nanoparticles were added to adhesives at 0.05% and 0.1% (by weight) (experimental groups), and scanning electron microscopy was used to observe the uniformity of the modified adhesives. The Single Bond Universal adhesive and the modified adhesives were then used to prepare dentin-composite resin blocks. The microtensile bond strength and microleakage of the prepared dentin-composite resin blocks were determined with or without thermocycling. The colony-forming units (CFU) of S. mutans cultured with the adhesives were evaluated, and the microtensile bond strength and microleakage of each group were tested after treatment with S. mutans. The differences in the microtensile bond strength or CFU were analyzed by using the 2-way analysis of variance and independent sample t test. The differences in microleakage between the groups were evaluated by using the Mann-Whitney test (α=.05). ResultsSilver nanoparticle-modified adhesives exhibited uniform morphologies without agglomeration and exhibited a homogeneous adhesive layer in dentin-composite resin blocks. The microtensile bond strength and microleakage of the modified adhesives were similar to those of the control group, with or without thermocycling (P>.05). However, thermocycling reduced the bond strength significantly (P<.001). Self-etch adhesives incorporated with silver nanoparticles showed significant antibacterial activities after less than 6 months of aging treatment. The modified adhesives did not exhibit a decreased bond strength after S. mutans exposure (P>.05), while the control group exhibited a markedly decreased bond strength after S. mutans exposure (P<.05). ConclusionsSilver nanoparticle-modified adhesives showed excellent antibacterial activities against S. mutans and resisted the destruction of dentin bond strength caused by S. mutans while not compromising the bonding properties of Single Bond Universal self-etch adhesives.

Effects of Alternative Solvents in Experimental Enamel Infiltrants on Bond Strength and Selected Properties.

To evaluate different concentrations of solvents (tetrahydrofuran (THF) and dimethyl sulfoxide (DMSO) and monomers on the degree of conversion, microtensile bond strength, and mechanical properties of experimental resin infiltrants. Resin infiltrants were formulated and divided into eleven groups: (1) Icon, (2) 75% TEGDMA (T) +25% UDMA (U), (3) T +25% BIS-EMA (B), (4) T + U +0.5%DMSO, (5) T + U +5% DMSO, (6) T + U +0.5% THF, (7) T + U +5% THF, (8) T + B +0.5% DMSO, (9) T + B +5% DMSO, (10) T + B +0.5% THF, and (11) T + B +5% THF. One hundred and ten bovine mandibular incisors were sectioned, treated, and destined to the degree of conversion, tensile cohesive strength, microtensile bond strength, flexural strength, and elastic modulus. Data were submitted to one-way ANOVA and Tukey's test (α = 0.05). The degree of conversion was lowest for T + B +5%THF (41.9%) and highest for T + U +5%THF (62.1%). In flexural strength and E-modulus, the T + B (96.5 MPa and 0.49 GPa) obtained the highest values and the lowest for T + U +5% DMSO (18.5 MPa and 9.7 GPa). Icon showed the highest bond strength (19.3 MPa) and cohesive strength (62.2 MPa), while T + U +5%DMSO (9.7 MPa) and T + B +5% DMSO (9.8 MPa) the lowest values and T + B +0.5% DMSO (12.3 MPa) the lowest cohesive strength. The addition of lower concentrations of DMSO or THF (0.5%) did not impair bond strength or significantly affect monomer conversion, but reduced the mechanical properties of resin infiltration.

Effect of dentin biomodification using natural collagen cross-linkers on the durability of the resin-dentin bond and demineralized dentin stiffness

ObjectiveThe purpose of this study was to evaluate the effect of using natural cross-linkers as sumac and curcumin on the durability of the resin-dentin bond and stiffness of demineralized dentin matrix. MethodsThirty sound molars were divided into 5 groups: Control (CO), Grape Seed extract (GSE), Cacao seed extract (CSE), Sumac extract (SE) and Curcumin extract (CE). The teeth had their coronal dentin exposed, etched, and pre-treated for 1 min with the extracts. Teeth were then bonded using Single-Bond II adhesive and 4 mm composite was built up on dentin surface. Teeth were sectioned into 1 × 1 × 8mm beams and their micro-tensile bond strength (μTBS) was tested after 24 h and 6 months of water storage.For stiffness testing, 15 teeth were sectioned to obtain dentin beams (1 × 1 × 6.5 mm), the beams were demineralized in 10% phosphoric acid then rinsed and divided into 5 groups. Beams were then immersed in their respective extract solution for 1 min after which they were subjected to a 3- point loading test using a universal testing machine to calculate their modulus of elasticity. ResultsAfter 24 h, no significant difference in μTBS was shown between all groups. After 6 Months, GSE, CE, and SE showed significantly higher μTBS compared to CO (p ≥ 0.05). For the modulus of elasticity; only GSE showed a significantly higher modulus compared to other groups. Clinical relevanceThe application of grape seed extract, curcumin and sumac extract as dentin pre-treatments appear to be a promising approach to enhance the durability of the resin-dentin bond in a clinically relevant application time.

Effect of a novel pretreatment on the microtensile bond strength of universal adhesives with dentin

Background/purpose: The quality of the hybrid layer is of great importance for dentin bonding. The purpose of this study was to develop a novel copper-based pretreatment and investigate the effect of the pretreatment combined with universal adhesives on the dentin bond strength. Materials and methodsEtch-and-rinse adhesive Single Bond 2 (SB2) and two universal adhesives Prime Bond Universal (PBU) and Single Bond Universal (SBU) were selected. The dentin surfaces were pretreated with CuSO4 solution and K2HPO4 solution in turn (Cu–P pretreatment), and the adhesive was applied following the manufacturer's instructions. There were four groups of Cu–P pretreatment: HH-Cu (1.5 mol/L CuSO4 + 1.0 mol/L K2HPO4); H–Cu (0.15 mol/L CuSO4 + 0.1 mol/L K2HPO4); L-Cu (0.015 mol/L CuSO4 + 0.01 mol/L K2HPO4); and LL-Cu (0.0015 mol/L CuSO4 + 0.001 mol/L K2HPO4). The microtensile bond strength (μ-TBS) and fracture mode were determined. The dentin surface after pretreatment and the antimicrobial properties of the pretreatment agent were also evaluated. ResultsThe minimum inhibitory concentration and minimum bactericidal concentration of Cu–P pretreatment were 0.012 mol/L CuSO4 + 0.008 mol/L K2HPO4. Combined with SB2, the H–Cu and L-Cu groups showed a higher μ-TBS (P < 0.01), while the HH-Cu group showed a lower μ-TBS (P < 0.001), and the LL-Cu group showed a similar μ-TBS with the control group without Cu–P pretreatment. Combined with universal adhesives PBU and SBU, the H–Cu and L-Cu groups also showed significantly increased μ-TBS (P < 0.01). ConclusionThe copper-based pretreatment in combination with universal adhesives improved the dentin microtensile bond strength.

Long-term Evaluation of Bonding Performance of Universal Adhesives based on Different Dentinal Moisture Levels.

To evaluate the microtensile bond strength (μTBS) and silver nitrate uptake (SNU) of three universal adhesives used in etch-and-rinse (ER) and self-etch (SE) modes on dry, wet, and oversaturated dentin surfaces after 24 h and 1 year of water storage. The morphology of the hybrid layer (MHL) and the degree of conversion (DC) were also evaluated. Human molars were divided into 36 groups according to combinations of the following variables: (i) universal adhesives (Ambar Universal APS [AMB], Prime&Bond Active [PBA], Scotchbond Universal Adhesive [SBU]), (ii) adhesive strategies (ER or SE), (iii) moisture level (dry, wet, or oversaturated dentin surface), and (iv) storage time (24 h or 1 year). After restoration, the specimens were sectioned into resin-dentin sticks and tested for μTBS and SNU according to storage time. For MHL, the specimens were sectioned and evaluated after 24 h using SEM. DC was evaluated using FTIR. ANOVA and Tukey's test were used for statistical analyses (5%). When 24-h vs 1-year data were compared, there was a significant decrease in μTBS and an increase in SNU values for the majority of experimental groups (p < 0.0001). On dry (ER) and oversaturated (ER and SE) dentin, AMB showed higher μTBS than did PBA (p < 0.00001). No significant decrease in μTBS was observed when universal adhesives were applied in the SE mode to dry dentin (p > 0.05). Regarding SNU, at all moisture levels, AMB showed lower SNU values than SBU (p < 0.001). Regarding MHL, SBU showed several imperfections when applied to oversaturated dentin in comparison with AMB and PBA. Regarding DC, when dentin was kept dry or was oversaturated, AMB showed a higher DC than PBA (p < 0.0001). The behavior of the different universal adhesives evaluated did not vary when applied to wet or dry dentin. However, the results with oversaturated dentin were dependent on the universal adhesive. Independent of the moisture level and the universal adhesive evaluated, significant degradation of the bonding properties occurred after 1 year of water storage, with the exception of universal adhesives applied to dry dentin in the SE strategy.

Comparative Evaluation of Microtensile Bond Strength in Three Different Dentin Luting Agents: An In vitro Study.

Long-term clinical success on indirect restorations is largely determined by bonding efficiency of the luting agent, with adhesion to dentin being the main challenge. Therefore, aim of this study was to assess the microtensile bond strength when using flowable resin composite, preheated resin composite and dual self-adhesive resin cement as dentin luting agents. Occlusal thirds of molar teeth were cut and randomly divided into 3 groups to be cemented: RelyX™U200, Filtek™ Z250 XT- preheated to 70° and Filtek Flow™ Z350XT. They were then thermocycled 5000 times between 5+/-2°C and 55+/-2°C. Subsequently, 10 microbars per group were prepared. The 30 samples were placed in saline solution for 24 hours at room temperature prior to microtensile test. This was performed with a digital universal testing machine at a crosshead speed of 0.5 mm/min. The bond strength values obtained were analyzed in Megapascals (MPa). Measures of central tendency such mean and measures of dispersion such standard deviation were used. In addition, the Kruskall Wallis non-parametric test with Bonferroni post hoc test was applied, considering a significance value of 5% (P < 0.05), with type I error. The dentin microtensile bond strengths of preheated resin composite, flowable resin composite and dual self-adhesive cement were 6.08 ± 0.66 Mpa, 5.25 ± 2.60Mpa and 2.82 ± 1.26Mpa, respectively. In addition, the preheated resin composite exhibited significantly higher microtensile bond strength compared to the dual self-adhesive cement (P < 0.001). While the flowable resin composite showed no significant difference with the dual self-adhesive cement (P = 0.054) and the preheated resin composite (P = 0.329). The microtensile bond strength in dentin was significantly higher when using a preheated resin composite at 70°C as a luting agent compared to dual self-adhesive cement. However, the preheated resin composite showed similar microtensile bond strength compared to the flowable resin composite.

Dentinhaftung bioaktiver Füllungsmaterialien für die Kinderzahnheilkunde

Aim: Bioactive materials are of interest for dental restoration in children with high caries risk. An important parameter for clinical success is durable adhesion to tooth hard tissues. Therefore, the present study evaluated dentin bonding behavior of two bioactive materials (ACTIVA BioACTIVE-RESTORATIVE [Acti, Pulpdent, Watertown, MA, USA] using All Bond Universal [BISCO, Schaumburg, IL, USA], and Cention N bonded with Adhese Universal [Cent, Ivoclar Vivadent, Schaan, Liechtenstein]) compared to a bonded resin composite (Filtek Z250 [FZ250, 3M Oral Care Dental Products, St. Paul, MN, USA] with OptiBond FL [Kerr, Biberach, Deutschland]) and a conventional glass ionomer cement (Fuji Triage pink [FTp, GC Corporation, Tokyo, Japan]) using Cavity Conditioner (GC Europe, Löwen, Belgien).Materials and methods: Twenty-eight caries-free third molars were randomly assigned to four groups (n = 7). Crowns were ground flat to expose dentin. Specimens were pretreated according to the manufacturers' instructions and built-up in 0.5-2 mm layers with composite. After storage (24 h at 37 °C in distilled water), specimens were cut into resin-dentin beams (0.36 mm2 for Acti, Cent, and FZ250; 1 mm2 for FTp) and subjected to microtensile bond strength testing. Additional micromorphological analyses were done using both light and scanning electron microscopy. Statistical appraisal was carried out using one-way analysis of variance (ANOVA; modified least significant difference [LSD] test; p <0.05). Results: Dentin bond strengths were (in MPa, numbers I-III indicate significant differences between groups): FZ250: 63.9 ± 8.3 (I); Acti: 52.1 ± 8.2 (II); Cent: 51.4 ± 10.9 (II); FTp: 3.7 ± 0.9 (III). A pronounced hybrid layer was only found in FZ250. The investigated bioactive restorative materials showed lower dentin adhesion compared to the bonded resin composite, but 13-fold higher values than the GIC (FTp).Conclusion: When adhesively bonded, the bioactive materials under investigation exhibited good dentin bonding behavior. In minimally invasive restorations, we recommend using them with a separate bonding step. However, further studies must show whether this impairs the caries-inhibiting, bioactive effect of the materials.

Effect of surface treatments on bond durability of zirconia-reinforced lithium silicate ceramics: An in vitro study

Statement of problemThe influence of surface treatments on the bond durability of zirconia-reinforced lithium silicate ceramics (ZLS) is unclear. PurposeThe purpose of this in vitro study was to evaluate the effect of different surface treatments on the bond durability of zirconia-reinforced lithium silicate ceramic after long-term thermocycling. Material and methodsFive computer-aided design and computer-aided manufacturing (CAD-CAM) dental ceramic blocks, including 2 zirconia-reinforced lithium silicate ceramic materials (Vita Suprinity/VS and Cetra Duo/CD), 2 commonly used glass-ceramic materials (e.max CAD/EM and Empress CAD/EP), and 1 yttria-stabilized zirconia (Y-TZP, Zenostar/ZS) were tested. Rectangular ceramic blocks were divided into 6 groups and subjected to different surface treatments: group Control (no treatment), group Uni (universal adhesive), group HF (hydrofluoric acid), group CoJet, group HF+Uni (HF and universal adhesive), and group CoJet+Uni (CoJet and universal adhesive). Subsequently, the specimens were cemented to composite resin blocks, sectioned into rectangular microbars of approximately 2×2×12 mm in size, and assigned to 2 groups with and without 100 000 thermal cycles (n=15 per group). The microtensile bond strength (μTBS) test was performed using a universal testing machine. Failure modes were observed with a stereomicroscope and scanning electron microscope (SEM). Three-way analysis of variance (ANOVA) followed by post hoc pairwise comparisons was performed to evaluate the effects of surface treatments, ceramics, and thermocycling on μTBS (α=.05). ResultsThe μTBS (MPa) was affected by the surface treatment (P<.001), ceramic type (P<.001), and thermocycling (P<.001). The bond strength after HF etching and universal adhesive treatment was highest in glass-ceramic groups (VS, CD, EP, and EM), while CoJet combined with universal adhesive indicated the highest bond strength in the ZS group before (34.3 ±4.2 MPa) and after thermocycling (16.0 ±2.9 MPa). No significant differences for μTBS were found among ZLS (VS and CD), lithium disilicate ceramic group (EM), and leucite-based ceramic group (EP, P>.05), but they demonstrated better bond strength than zirconia (ZS group, P<.01) after thermocycling. Adhesive failure increased in all groups, and the cohesive failure of glass-ceramic decreased after thermocycling. ConclusionsZLS showed similar μTBS with traditional glass-ceramics, including lithium disilicate ceramic and leucite-based ceramic, and more durable bonding than zirconia to resist thermocycling. Moreover, the combination of HF and universal adhesive treatments was the most effective method for ZLS among all the different surface treatments in this study.

Effect of Method of Removing Caries-Affected Dentin on the Bond Strength of Composite Resin to Root Canal Dentin.

The adhesion of composite resin to caries-affected dentin differs from the adhesion of resin to sound dentin. We evaluated the bond strengths of dual-cure resin composites applied to caries-affected root canal dentin under various clinical conditions and using several caries removal indicators. In the dye stain 1 group, caries were removed to a pale pink stain level using a caries detector. In the dye stain 2 group, caries were removed to a stain-free level using a caries detector. In the probing group, caries were removed to the level of hardness based on probing with a sharp explorer. Additionally, a sound dentin group was used as a control. We compared the resin composite microtensile bond strengths and failure mode distribution among the groups. The bond strengths (MPa) of the probing (64.6 ± 11.9) and the sound dentin (68.7 ± 11.1) groups were significantly higher than those of the dye stain 1 (46.9 ± 7.9) and 2 (47.5 ± 8.4) groups (p &lt; 0.05). The removal of caries-affected dentin using a dentin-hardness-based technique showed higher tensile strength than that using a dye stain technique involving removal to any color level. Thus, the caries removal technique used on root canal dentin affects the bond strength of the resin composite.

Appropriate Immediate Dentin Sealing to Improve the Bonding of CAD/CAM Ceramic Crown Restorations.

This study aimed to use quantitative and qualitative evaluations based on micro-tensile bond strength (μTBS) to clarify the appropriate immediate dentin sealing (IDS) approach for improving the bonding of CAD/CAM ceramic crown restorations. Forty-eight extracted human molars were prepared to obtain standardized abutment specimens and divided into three groups: no IDS (group C: control), IDS performed by a single application of an all-in-one adhesive system (group A), and IDS performed by the combined application of an adhesive system and a flowable resin composite (group F). All specimens were restored with a ceramic crown fabricated by a chair-side CAD/CAM system and were divided into no-stress and stressed groups. After cyclic loading (78.5 N; total, 3 × 105 cycles; 90 cycles/min) on the specimens in the stressed group, all specimens were sectioned. The μTBS values for the occlusal and mesioaxial walls were measured (n = 16) and analyzed statistically. The quantitative bonding performance of groups A and F were superior to that of group C, regardless of the cyclic loading and abutment wall conditions. Group F showed the maximum bond strength and the highest bond durability in the qualitative bonding performance even under the cyclic loading condition simulating clinical mastication.

Effect of adhesive strategy on resin cement bonding to dentin.

The cement bonding strategy and the polymerization mode can influence the prognosis of indirect restorations. The microtensile bond strength (μTBS) and dentin endogenous enzymatic activity of a dual-cure resin cement (PV5) used in combination with two dentin surface conditioners (accelerator-enhancer primer, TP or universal adhesive, UA) were evaluated. PV5 was used to lute composite overlays after dentin treatment with TP or UA. The resin cement was self-cured, SC (1 h at 37 °C) or dual-cured, DC (20 s light-cure followed by 15 min self-cure at 37°C). The μTBS test, fractographic analysis, and the in situ zymography evaluations were performed after 24 h (T0 ) or 1 yr (T12 ) of artificial storage. Data were statistically analyzed (α=0.05). TP/DC obtained the highest adhesive strengths (45 ± 9 and 36.6 ± 8), while UA/SC (17 ± 8 and 11 ± 4) the lowest, both at T0 and T12 , respectively. DC resulted in superior bonding values than the SC, independent of the dentin surface treatment (p < 0.05). The type of adhesive, curing mode and aging influenced the gelatinolytic activity (p < 0.05). The dual-cure resin cement used in combination with its accelerator-enhancer primer showed superior bonding performances with respect to universal adhesive. Dual-curing the resin cement was determinant to enhance bonding capability over time, independent of the adhesive strategy. Clinicians must be aware to faithfully follow manufacturer's recommendation regarding the adhesive strategy suggested with the resin cement used.

Effect of Fast High-Irradiance Photo-Polymerization of Resin Composites on the Dentin Bond Strength.

This study investigated the influence of conventional (10 s at 1160 mW/cm2) and fast high-irradiance (3 s at 2850 mW/cm2) light curing on the micro-tensile bond strength (μTBS) of bulk-fill resin composites bonded to human dentin. Sixty-four extracted human molars were ground to dentin and randomly assigned into eight groups (n = 8 per group). After application of a three-step adhesive system (Optibond FL), four different bulk-fill composites (two sculptable and two flowable composites) were placed. Of these, one sculptable (Tetric PowerFill) and one flowable (Tetric PowerFlow) composite were specifically developed for fast high-irradiance light curing. Each composite was polymerized with the conventional or the fast high-irradiance light-curing protocol. The specimens were cut into dentin-composite sticks, μTBS was determined and failure modes were analyzed. Statistical analysis was performed using t-test for independent observations and one-way ANOVA. A statistical difference between the curing protocols was only found for Tetric PowerFlow, where the conventional protocol (23.8 ± 4.2 MPa) led to significantly higher values than the fast high-irradiance light-curing protocol (18.7 ± 3.7 MPa). All other composite materials showed statistically similar values for both polymerization protocols. In conclusion, the use of fast high-irradiation light curing has no negative influence on the μTBS of the investigated high-viscosity bulk-fill composites. However, it may reduce the dentin bond strength of flowable bulk-fill composite.

Benzyldimethyldodecyl Ammonium Chloride Doped Dental Adhesive: Impact on Core's Properties, Biosafety, and Antibacterial/Bonding Performance after Aging.

Current dental adhesives lack antibacterial properties. This study aimed to explore the effect of incorporating benzyldimethyldodecyl ammonium chloride (BDMDAC) on the degree of conversion, contact angle, ultimate tensile strength (UTS), microtensile bond strength (µTBS), cytotoxicity, antibacterial and bonding performance after artificial aging. A dental adhesive was doped with BDMDAC in the concentration range of 1-5 wt.%. For antibacterial assays, the BDMDAC compound was subject to planktonic cells of Streptococcus mutans. Then, after incorporation into the dental adhesive, an S. mutans biofilm model was used to grow 48 h-mature biofilms. The biofilms grown over the formulated materials were assessed by colony-forming unit (CFU) counting assay and fluorescence microscopy staining. In addition, the cytotoxicity was evaluated. Samples were subjected to 10,000 thermal cycles for aging and evaluated by UTS, µTBS, and CFU. Incorporating BDMDAC did not increase the cytotoxicity or change the physical properties when the mass fraction of the BDMDAC was 1-5 wt.%. The UTS of BDMDAC-doped adhesives was not impaired immediately or over time. A significant bacterial reduction was obtained for the mass fraction of the BDMDAC greater than 3 wt.%. However, the BDMDAC-doped adhesives did not offer an antibacterial effect after artificial aging. The overall results indicate that the BDMDAC strategy has the potential to control of microbial growth of cariogenic planktonic cells and biofilms. However, other new technological approaches are needed to overcome the deleterious effect of BDMDAC release over time such as those based on the principle of drug delivery systems whereby the BDMDAC is transported on microparticles or core shells, providing tangible benefits to oral health over time.

Universal Adhesives: Evaluation of the Relationship between Bond Strength and Application Strategies—A Systematic Review and Meta-Analyses

Adhesive resins with guided application protocols have been developed with the main goal of reducing the number of clinical steps. Universal Adhesives (UA) can be applied with both Self-Etch (SE) or Etch-and-Rinse (ER) adhesion strategies. This review aims to evaluate the bond strength of UA, applied to dental tissues, by a systematic bibliometric review of in vitro studies. The research question, through the PICO model, aimed to assess the current knowledge of the immediate and long-term bond strength of UA, applied with a direct restorative technique. PubMed and ScienceDirect database searches focused on the bond resistance of UA applied with the ER and SE strategies. Studies assessing shear bond strength and microtensile bond strength, in both enamel and dentin, were included. From 1109 screened articles, 12 fulfilled the inclusion criteria. The bond strength of UA to enamel showed better results with the ER approach, while the adhesion strategy did not significantly affect the bond strength of UA to dentin. Evidence from in vitro studies has tended to suggest that the use of the SE adhesion approach seems to be a better choice to improve the bond strength to the dentin. The selective enamel etching is advisable when applied with the SE adhesion approach to optimize the UA bond strength to the enamel.

Antibacterial effect, cytotoxicity, and bond strength of a modified dental adhesive containing silver nanoparticles.

This study aimed to evaluate the antibacterial effect, cytotoxicity, and microtensile bond strength of an adhesive system containing silver nanoparticles (NAg). NAg was synthesized and incorporated (500 and 1000ppm) into Scotchbond Multi-Purpose (SBMP) primer and bond. A microtensile bond test (μTBS) was performed after 24h and 1year. The adhesive interface was characterized using a confocal Raman microscope. The antibacterial activity was assessed using agar diffusion and biofilm inhibition assays (S. mutans). MTT assay was used to assess the cytotoxicity of NAg-conditioned culture media on human dental pulp stem cells (hDPSCs). The results were statistically analyzed using analysis of variance and Tukey's tests (α = .01). Incorporating 500 and 1000ppm of NAg in the SBMP did not affect the μTBS after 24h (p > 0.05). However, in the 1year evaluation, 500ppm presented the highest μTBS values (p < 0.05). The addition of NAg at 500 and 1000ppm in the primer and bond led to larger inhibition halos and colony-forming units than the control (p < 0.05). For the unpolymerized and polymerized groups, the combination of primer and bond presented the highest cytotoxic effects on hDPSCs (p < 0.05). In conclusion, incorporating 500 or 1000ppm of NAg into an etch-and-rinse adhesive system led to an antibacterial effect without altering the cytotoxicity. SBMP at 500ppm presented a higher μTBS at 1 year.

Influence of prophylaxis with amino acid glycine powder and sodium bicarbonate jet on the bond strength of dental enamel

Aim: To compare the influence of prophylaxis with sodium bicarbonate and amino acid glycine powder on the bond strength of bovine teeth enamel and on the properties of two adhesive systems. Methods: Thirty-six extracted bovine incisors were randomly divided into six groups (n = 6) according to the prophylactic treatment received: no prophylactic treatment (NT), sodium bicarbonate powder (SB), and glycine powder (GL). Each group was subdivided into 2 groups based on what adhesive systems were used: conventional system (A) and universal system (B). Composite resin was applied on the buccal surface of the teeth in a block measurement 8x8x6 mm. The specimens were cut to obtain beams measuring 1.0 x 1.0 mm and were subjected to microtensile bond strength tests. Results were compared using two-way ANOVA (p ≤ 0.05). Results: The GLA group obtained the highest bond strength value for the conventional adhesive (18.97 MPa), but the GLB group obtained a lower strength value than the SBB group (GLB: 21.05 MPa and SBB: 22.29 MPa) (p &lt; 0.05). Conclusions: Cleaning of the enamel surface increases the adhesive properties of restorative materials, and the bond strength was more effective in the group that received glycine prophylaxis and the conventional adhesive system.

Effect of phytic acid on bond strength and interfacial integrity of universal adhesive to deep dentin.

This study investigated the effect of phytic acid (IP6) in different concentrations and application times on microtensile bond strength (µTBS) and interfacial integrity of universal adhesive to deep dentin. Flat deep dentin surfaces of 48 human molars were either etched with 37% phosphoric acid (PA) for 15 sec (control); or received no acid treatment and universal adhesive was applied directly in a self-etch mode (SE); or divided according to IP6 concentration (C) into two main groups: C1, 0.5%, and C2, 1%. Specimens of IP6 groups were further subdivided into three subgroups according to application time of IP6 (T) where; T1, 15 sec; T2, 30 sec and T3, 60 sec. Single Bond Universal Adhesive was then applied and resin composite blocks were built-up. Forty Specimens were then sectioned to produce resin/dentin beams that were used for µTBS testing using a universal testing machine. The remaining eight specimens were sectioned into slabs that were immersed into ammonical silver nitrate solution and nanoleakage was observed using a field emission scanning electron microscope (FE-SEM). The results showed that the application of IP6 in 0.5% and 1% produced significantly higher µTBS and less nanoleakage compared to PA and SE groups. Also, the application of IP6 for 60 sec recorded the highest µTBS and the lowest nanoleakage followed by 30 sec, and 15 sec respectively. Therefore, conditioning of deep dentin with IP6 enhances µTBS and interfacial integrity of universal adhesive to deep dentin in comparison to PA etching or using the universal adhesive in SE mode.

Effect of Silver Diamine Fluoride and Potassium Iodide on Micro-tensile and Shear bond strength of Glass Ionomer Restoration to carious Dentin of Primary Molar (In vitro study)

Effect of Silver Diamine Fluoride and Potassium Iodide on Micro-tensile and Shear bond strength of Glass Ionomer Restoration to carious Dentin of Primary Molar (In vitro study)

Choosing the Adhesive for Microtensile Bond Strength Tests

Abstract Dental fillings are one of the most widespread minimal invasive procedures in modern restorative dentistry. Thanks to the advantages of recently developed filling materials, adhesive systems, and filling techniques, it is possible to create high strength, long-lasting dental fillings. Qualifying these structures is a complicated procedure; the most common method is the use of a microtensile bond strength test, for which specimens need to be formed and stabilised with adhesives in special jigs. During our research, three different cyanoacrylates were examined to find the ideal adhesive for bonding the metal and dentin and the metal and EverX short fibre composite, respectively.