Journal of Adhesive Dentistry最新文献

Purpose: To evaluate the microtensile bond strength (µTBS) of three universal adhesives to dentin contaminated with a hemostatic agent.

Materials and methods: Ninety-six human premolars were cut to expose mid-coronal dentin. The teeth were randomly divided into a control group (uncontaminated dentin) and an experimental group in which a hemostatic agent was applied (contaminated dentin). Each group was further divided into 6 subgroups according to universal adhesives - SBU (Single Bond Universal), OPU (OptiBond Universal), CBQ (Clearfil Universal Bond Quick) - and etching mode, either etch-and-rinse (ER) or self-etch (SE). Following adhesive application, composite was placed in two increments and light cured. The specimens were stored in distilled water at 37°C for 24 h. The µTBS test was performed using a universal testing machine. Failure mode was assessed using a light microscope. The data were statistically analyzed using three-way ANOVA followed by Scheffe's test (p < 0.05). The resin-dentin interface was observed using scanning electron microscopy.

Results: Significantly lower bond strength was observed when the universal adhesives were bonded to contaminated dentin in SE mode (p < 0.05). In contrast, the µTBS of the universal adhesives in ER mode was not affected by contamination (p > 0.05). The µTBS of CBQ to contaminated dentin was significantly lower than that of the other adhesives. Observation of the resin-dentin interface revealed limited resin penetration when the universal adhesive was applied in SE mode on contaminated dentin.

Conclusion: Contaminating the dentin with a hemostatic agent significantly reduced the µTBS of the universal adhesives in SE mode. However, this adverse effect was not found when the universal adhesives were used in ER mode.

Purpose: To investigate the changes in the enamel bond performance of a two-step adhesive containing a primer derived from a universal adhesive in the early phase before 24 h and compare them to those of other adhesives. The Knoop hardness number (KHN) of the cured adhesive layers and resin composite was measured.

Materials and methods: A new two-step adhesive using universal adhesive technology, G2-Bond Universal, was tested. Two conventional two-step adhesives, Clearfil SE Bond 2 and OptiBond eXTRa, and an established universal adhesive, Scotchbond Universal Plus Adhesive, were used as comparison materials. Twelve specimens per group were used to measure the shear bond strength (SBS) to bovine enamel in different etching modes. The bonded specimens were stored in distilled water at 37°C for 5 min or 1, 6, 12, or 24 h before SBS testing. The KHN of the adhesive layer and resin composite was determined after the same storage periods as for SBS testing.

Results: All adhesives exhibited increased SBS with prolonged storage periods, irrespective of the etching mode. The KHN of the adhesive layer and resin composite increased over time.

Conclusions: There were strong positive correlations between the SBS and KHN of the adhesive layer and resin composite. Phosphoric acid pre-etching of enamel effectively increases enamel bond performance. The two-step adhesive G2-Bond Universal demonstrated significantly higher bond strength in the early phase than the other adhesives in self-etch mode.

Purpose: 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.

Materials and methods: 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%).

Results: 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).

Conclusion: 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.

Purpose: To evaluate the effect of universal adhesives on the long-term bond strength to yttria-stabilized tetragonal zirconia polycrystal (Y-TZP).

Materials and methods: Polyethylene tubes filled with composite cement containing 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) were adhesively luted to 60 fully sintered Y-TZP slabs (7 x 7 x 2 mm) with or without (control) previous application of a 10-MDP-based adhesive (All Bond Universal, Bisco) - ABU; Clearfil Universal Bond Quick, Kuraray Noritake - CUB; Scotchbond Universal Adhesive, 3M Oral Care - SUA) on the zirconia surface. The bonded specimens were stored in water for 24 h, 6 months, or 1 year and subjected to microshear bond strength testing. The data were analyzed by one-way ANOVA and Tukey's test (p < 0.05). The contact angle was measured after adhesive application to evaluate surface wettability. The adhesive-treated specimens were analyzed with x-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) for chemical characterization.

Results: The application of a 10-MDP-based adhesive significantly improved bond strength of composite cement to zirconia when compared to the control group (no adhesive application) (p < 0.05). One-year water storage significantly decreased bond strength for ABU- and CUB-bonded specimens, but not for SUA-bonded specimens. The analysis by XPS and ToF-SIMS showed peaks of carbon, phosphorus, and silicon in all adhesive-treated specimens.

Conclusions: One-year water storage affected the bond strength of composite cement to zirconia when All Bond Universal or Clearfil Universal Bond Quick were used.

Purpose: To evaluate the effect of different pretreatment protocols and adhesives on the shear bond strength and surface morphology of aprismatic enamel.

Materials and methods: Human maxillary incisors (N = 120) were assigned to five different groups according to pretreatment: 1) no treatment; 2) glycine; 3) sodium bicarbonate; 4) Al2O3 and 5) extra-fine bur. Then the teeth were divided into three subgroups, according to the adhesive applied: 3-step etch-and-rinse (ER), universal adhesive in ER mode, and universal adhesive in self-etch (SE) mode. Shear bond strength (SBS) testing was performed with a universal testing machine. For SEM observation, fifteen human molars were collected and analyzed after pretreatment with/without etching with 37% H3PO4 for 30s.

Results: Al2O3 showed higher SBS than all other groups considered. Comparable SBS values were obtained for other pretreatments. Universal adhesive in E&R mode performed better than did 3-step E&R and universal adhesive in SE mode. SEM images showed visible differences in enamel surface roughness.

Conclusions: Airborne-particle abrasion with Al2O3 followed by etching with H3PO4 increased SBS on aprismatic enamel. The combination of airborne-particle abrasion with alumina powder followed by 15 s of H3PO4 etching and application of a universal adhesive in E&R mode proved to be the most effective adhesive protocol.

Purpose: The purpose of this study was to assess the effect of aging and alumina-particle air abrasion at different pressures on the bond strength of two luting composites to a translucent 3Y-TZP zirconia.

Materials and methods: Half of the 192 disk-shaped zirconia specimens were aged in an autoclave (group A) for 20 h (134°C, 2 bar), and the other half was not aged (group N). For each group, a different surface treatment was applied: as-sintered (group SIN), alumina-particle air abrasion either at 1 bar (group 1B) or at 2.5 bar (group 2.5B). Disks were bonded to Plexiglas tubes filled with composite resin using a phosphate monomer-based luting composite (group SA) or with a separate phosphate monomer containing primer before using a phosphate-monomer-free luting composite (group V5). All specimens were subjected to tensile bond strength testing (TBS) before and after thermocycling.

Results: There were no statistically significant differences caused by autoclave aging for the test groups before thermocycling, except for the A-SIN-SA group, where the TBS decreased significantly. The variation of the aluminaparticle air abrasion pressure showed no statistically significant effect, except in the N-1B-V5 group, where TBS was significantly lower than N-2.5B-V5. After thermocycling, the TBS of most groups decreased significantly. Specimens of the primer group, which were abraded at 1 bar, showed a significant decrease in TBS in comparison with alumina-particle air abrasion at 2.5 bar.

Conclusion: Twenty hours of autoclave aging had almost no influence on the bond strength of the test groups. For the primer/resin bonding system, higher pressure during alumina-particle air abrasion might help obtain a higher and more durable bond strength to zirconia.

Purpose: To evaluate the kinetics of polymerization and shrinkage stress of resin cements, as well as their bond strength to dentin after 24-h or one-year water storage.

Materials and methods: Three conventional resin cements were evaluated: RelyX Ultimate (RUL), Panavia V5 (PNV), and Multilink N (MLN); and three self-adhesive resin cements: RelyX Unicem 2 (RUN), Panavia SA Cement Plus (PSA), and G-CEM LinkAce (GCL). Degree of conversion (DC), maximum polymerization rate (RPmax) and gel time values were obtained using Fourier-transform infrared spectroscopy (FTIR/ATR). Shrinkage stress values were determined with a tensiometer, using a universal testing machine (n=5). Indirect resin composite restorations (Solidex) were fabricated and cemented to the dentin surface using self-adhesive resin cements, or conventional resin cements with self-etching adhesive (n=5). Bonding performance was evaluated with the microtensile bond strength (µTBS) test after 24 h or one year of water storage.

Results: MLN exhibited a higher DC (76.7%), whereas the percentage of other materials differed slightly (ranging from 54% to 58.5%). The RPmax and shrinkage stress values differed significantly between the cements. PSA showed the longest gel time. Significantly higher µTBS were observed for conventional resin cements after 24-h and one-year storage; a decrease in µTBS was observed for MLN only.

Conclusion: Self-adhesive resin cements may not perform as well as conventional resin cements. Although both categories of cements presented similar polymerization kinetics and shrinkage values, the self-adhesive resin cements showed lower µTBS compared to those of conventional resin cements. Nevertheless, storage time only affected the bonding performance of MLN.

Purpose: To investigate the effects of dentin decontamination procedures with ethylenediaminetetraacetic acid (EDTA) after contamination with two hemostatic agents, ViscoStat (VS) and ViscoStat Clear (VSC), on the microtensile bond strength (μTBS) of two different universal adhesives, before and after thermocycling (TC).

Materials and methods: Dentin surfaces of 100 human caries-free molars were either contaminated with one of the hemostatic agents or contaminated and then decontaminated with EDTA before the universal adhesives Scotchbond Universal Adhesive (SBU) or Prime & Bond Active (PBA) were applied in self-etch mode. Composite buildups were made and the teeth were sectioned into sticks (n = 90). Half of them immediately underwent the μTBS test, the other half after aging via TC. The data were statistically analyzed using Welch's ANOVA and the Games-Howell post-hoc test (p < 0.05).

Results: Significant differences were observed between the groups (p < 0.001). When the dentin surface was contaminated with VSC, TC significantly reduced the mean bond strength, regardless of the universal adhesive. Decontamination with EDTA showed a significant decrease in bond strength after VS contamination and SBU application. The fracture analysis showed mainly adhesive fractures (78.8%) in all test groups.

Conclusion: As EDTA application did not significantly increase the μTBS of either universal adhesive in self-etch mode in-vitro, it cannot be recommended as a decontaminant.

Purpose: To evaluate the long-term clinical quality of subgingivally placed composite resin restorations and the inflammatory status of surrounding supracrestal gingival and periodontal tissues.

Materials and methods: Patients with at least one subgingival restoration with deep-margin elevation placed between 2010 and 2020 at Heidelberg University Hospital and Tübingen University Hospital were identified. A sound tooth was used as control. Intraoral examination including probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival bleeding index (GBI), and plaque control record (PCR) was conducted. The clinical quality of the restorations was evaluated using the modified FDI criteria. For comparison between control and test teeth, a logistic mixed-effects model was used for GBI, PCR, and BOP, while a linear mixed-effects model was used for CAL. Multivariable linear and logistic regressions were used to examine the influence of smoking, age of restoration, number of decayed, missing and filled teeth, use of interdental brushes, and CAL.

Results: Sixty-three patients were included in the study. The mean age of the restorations was 2.70 ± 1.90 years. There were no significant differences between test and control teeth with respect to inflammatory parameters BOP, GBI, and PCR. CAL was significantly higher in test teeth than in controls (p = 0.027). The regression models revealed that CAL has a significant influence on GBI (p = 0.008) and BOP (p < 0.001). A significantly increased GBI occurred especially on test teeth in patients who did not use interdental brushes daily (p = 0.010). The clinical quality of restorations was rated excellent or good in 70%, an no restoration was rated unacceptable.

Conclusion: No increased inflammation was observed on sites with subgingivally placed composite restorations over an observation period of approximately 3 years. Regular interdental brush use was associated with less gingival inflammation.

Purpose: To evaluate the 24-month clinical performance of a "no wait" universal adhesive with different application modes in comparison with an etch-and-rinsew and two-step self-etch adhesive in non-carious cervical lesions (NCCLs).

Materials and methods: A total of 234 non-carious cervical lesions in 34 patients were restored following 5 different adhesive approaches: 1. Clearfil Universal Bond Quick, self-etch mode (CUQ-SE); 2. Clearfil Universal Bond Quick, selective etch mode (CUQ-SLE); 3. Clearfil Universal Bond Quick, etch-and-rinse mode (CUQ-ER); 4. Clearfil SE Bond (self-etch adhesive) (CSEB); 5. Tetric N-Bond Universal, etch-and-rinse mode (TBU-ER). All NCCLs were restored with a nanohybrid composite (Tetric N-Ceram). The restorations were evaluated at baseline, 6, 12, and 24months of clinical service regarding retention, marginal adaptation, marginal discoloration, secondary caries, post-operative sensitivity, color match, surface texture using modified United States Public Health Service (USPHS) criteria.

Results: The patient recall rate at 24 months was 73.5%. Eleven restorations, 6 of the CUQ-SE group, 4 of the CSEB group and 1 of the TBU-ER group, were clinically unacceptable due to retention loss. Regarding marginal adaptation and discoloration, CUQ-SE and CSEB groups exhibited higher bravo scores than other groups after 24 months (p < 0.05). At the end of 24-month examinations, no significant differences were detected among the groups regarding secondary caries, post-operative sensitivity, color match and surface texture.

Conclusion: The clinical survival rates of the "no wait" universal adhesive at self-etch mode after 24 months were not acceptable. The "no wait" universal adhesive showed clinically acceptable performance in selective-etch and etch-and-rinse mode according to the evaluated USPHS criteria.