Journal of Adhesive Dentistry最新文献

Purpose: To evaluate the effect of irradiation with an optical-fiber device on the bond strength of hollow and partially opaque intraradicular posts.

Materials and methods: An optical-fiber accessory tip was attached to a light-curing unit to emit light through the central hollow of an experimental fiberglass post. The samples were divided into 4 groups (n = 80) according to the protocol (Variolink N [light cured] or Multilink N [dual-curing luting material]) and the light-curing mode (performed conventionally or with the optical fiber): GF: light-curing luting material; GFF: light-curing luting material and optical fiber; GD: dual-curing luting material; GDF: dual-curing luting material and optical fiber. The samples were tested immediately or after aging. Push-out bond strength, failure mode, degree of conversion (DC, assessed at the peak of 1750 cm-1), and stress distribution by finite element analysis were performed. Quantitative data were analyzed using 3-way ANOVA (luting material x light curing x depth) and 2-way ANOVA (aging x luting material), followed by Tukey's test.

Results: Bond strength was significantly affected by the luting material protocol (p < 0.001), depth (p = 0.010), and light curing mode (p = 0.031). The GFF group revealed higher bond strength in the middle and apical portions. The most frequent failure modes were adhesive in the apical portion for the GFF and GDF groups. The DC was higher for GF and GFF groups.

Conclusion: Using the optical-fiber device led to superior bond strength results when a dual-curing luting material was used.

Purpose: To evaluate whether varying thicknesses of universal adhesives utilizing the additional coating strategy would affect their microtensile bond strength (µTBS) to dentin, hardness, and elastic modulus (mechanical properties).

Materials and methods: Ninety-nine human maxillary premolars were cut to expose coronal dentin, ground with regular-grit diamond burs, and randomly distributed into 9 groups based on 1. adhesive: Scotchbond Universal Adhesive (SB; universal), G Premio Bond (GP; universal) and Clearfil Megabond 2 (MB; two-step self-etch; control); and 2. application strategy (one, two or three coats; each coat light cured). After adhesive application and resin composite buildup, the bonded teeth were stored in distilled water (37°C; 24 h). Resin-dentin sticks from eight premolars per group (each premolar yielded 3 sticks; n = 24 sticks altogether) were prepared for the µTBS test, followed by measurement of the adhesive thicknesses at their fractured ends using SEM. The mechanical properties of the adhesive layers produced by different coats were evaluated on separate resin-dentin slices (n = 3 teeth per group).

Results: Two coats significantly increased the µTBS (p < 0.001) of all the adhesives. The correlation between adhesive thickness and bond strength was positive for GP but negative for SB. MB did not show any correlation. Additional coating significantly increased the mechanical properties of GP (p < 0.05) but did not affect SB and MB (p < 0.05).

Conclusion: An additional adhesive coating over the manufacturers' recommendations improved the bond strength of all the adhesives tested. However, the increased mechanical properties of the adhesives with additional curing was material dependent.

Purpose: To evaluate the effect of two surface conditioning methods, namely conventional hydrofluoric acid vs self-etching primer, and the application of adhesive on the bond strength of resin cement to CAD/CAM glass-ceramics.

Materials and methods: Blocks (N = 96) (12 x 10 x 2.5 mm) were manufactured, 24 for each tested ceramic type: lithium silicate ceramic (LS), polymer-infiltrated ceramic (PIC), leucite-reinforced feldspathic ceramic (FD), and lithium-disilicate glass-ceramic (LD). For bond strength testing, 64 blocks were randomly divided into 16 groups (4 blocks per group) according to the following factors: ceramic: 4 levels; etching: 2 levels (HFS: hydrofluoric acid + silane or Monobond Etch & Prime [MEP]); and adhesive application: 2 levels, with (signified as A) and without. Then for each group, 15 resin cement cylinders (AllCem Dual, FGM) were built up. All specimens were subjected to thermocycling (10,000 cycles) and to shear bonding strength testing (SBS) (100 kgf, 0.5 mm/min). Mean shear stresses (MPa) were statistically analyzed by three-way ANOVA, Tukey's test, and Weibull analysis.

Results: The mean bond strength of group PIC-HFS-A (28.45 ± 7.6 MPa) was significantly higher than that of groups LS-HFS-A (12.11 ± 2.7MPa) and FDHFSA (20.86 ± 2.0MPa). Group PIC-HFS bond strength (25.02 ± 6.5 MPa) was significantly higher only when compared to group LS-HFS (15.82 ± 4.4 MPa). The LS group presented lower SBS compared to all other groups. No significant differences were found between HFS and MEP surface treatments.

Conclusion: Surface treatment with MEP promotes adhesion similar to that of HFS. Additional application of adhesive after the surface treatments did not improve the bond strength.

Purpose: To comparatively evaluate the elution of residual monomers (bis-GMA, bis-EMA, TEG-DMA, and HEMA) from two self-adhesive flowable resin composites, a giomer, and a nano-flowable resin composite over five different time intervals, using high-performance liquid chromatography (HPLC).

Materials and methods: Four flowable resin composites were investigated (Vertise Flow, Constic, Beautifil Flow Plus F03, and Filtek Z350 XT). Immediately after polymerization, each sample was immersed in 75% ethanol/water solution and stored in amber-colored bottles at room temperature. HPLC analysis was performed at predefined time intervals: 1 h, 24 h, 4 days, 8 days and 16 days. The extraction solution was changed after each analysis. Data were analyzed with repeated-measures ANOVA and one-way ANOVA with Tukey's post-hoc test at p < 0.05.

Results: The highest mean concentration of residual monomers was eluted from Beautifil, followed by Filtek, and both were significantly higher (p < 0.05) than the mean concentration of eluates from self-adhesive resin composites (Vertise Flow and Constic). Vertise Flow released significantly higher concentrations of HEMA than all the other tested materials. At 1 h post-immersion, 52.2% of monomers were eluted, and continued to elute at a reduced rate throughout the study duration. TEG-DMA was the fastest monomer to leach out, while bis-GMA exhibited significantly higher total mean concentration. The elution rate was significantly dependent on the molecular weight of the eluted monomers.

Conclusion: No specific elution behavior can be attributed to self-adhesive RBCs. Elution of residual monomers is dependent on each material's composition, resin matrix characteristics, and the monomer's molecular weight.

Purpose: To present a new restorative technique for the restoration of teeth with deep subgingival hard tissue defects extending down to the osseous crest without additional surgical or orthodontic interventions by combining mineral trioxide aggregate (MTA) and composite material.

Materials and methods: The MTA matrix technique starts by deeply inserting a metal matrix as far down to the bone level as possible. The matrix should then be fixated with a matrix holder in its end position. If the matrix band does not seal tightly in the deepest area of the cavity, small portions of MTA are carefully applied to the lower end of the inner side of the matrix band. The MTA acts as a barrier for fluid control. Additional haemostasis is not necessary. Subsequently, the tooth is restored with an etch-and-rinse adhesive and composite resin. The clinical effects were observed in a case series of three patients over a period of 3 to 4.5 years.

Results: Excellent outcomes were observed clinically and radiologically. Teeth restored with the MTA matrix technique showed no failures due to the materials used or due to secondary caries or periodontal inflammation after an observation period of 3 to 4.5 years. Probing depths ranged from 2 to 4 mm without bleeding on probing, including the subgingivally restored areas.

Conclusion: Although only a few casuistic observations are available to date, by using the MTA matrix technique, successful restoration of teeth with subgingival defects down to the alveolar bone crest seems possible without the need of additional surgical or orthodontic measures. Further clinical studies are necessary to confirm the feasibility of this technique.

Purpose: To investigate the influence of primers on polymerization kinetics of resin-based luting and its effect on the microhardness and bond strength to zirconia. Materials and Methods: Panavia V5 (PV; Kuraray Noritake) with Tooth Primer (TPprimer; Kuraray Noritake) or Clearfil Ceramic Primer (CPprimer; Kuraray Noritake), and RelyX Ultimate (RU; 3M Oral Care) with Scotchbond Universal (SUadhesive; 3M Oral Care) were evaluated. Polymerization kinetics of luting materials with or without primers (TPprimer or SUadhesive) were evaluated using Fourier transform near-infrared (FT-NIR) spectroscopy in self- and dual-curing modes (n = 5). Microhardness of luting materials was evaluated after 1, 12, and 24 h (n = 5). Shear bond strengths to zirconia ceramics (Katana Zirconia, Kuraray Noritake; and Lava Esthetic, 3M Oral Care) after 24 h and 1 year (n = 8) were assessed to determine the effect of the following surface treatments: no treatment, non-thermal atmospheric plasma, primer (CPprimer or SUadhesive), and the combination of plasma + primers. Statistical analyses were performed at a 5% significance level.

Results: PV achieved a significantly higher degree of conversion (DC) when TPprimer was used, while there was no increase in conversion for RU combined with SUadhesive. Light activation significantly improved polymerization, which also produced greater microhardness. CPprimer and SUadhesive significantly improved immediate bond strength to zirconia ceramics. However, after 1 year, only SUadhesive with RU was able to maintain the bond strength. Plasma surface treatment did not improve bonding to zirconia.

Conclusion: The use of primers improved the DC for PV only. Light curing produced higher conversion and microhardness for both resin-based luting materials. Bond strength to zirconia was improved when primers were used. However, only RU demonstrated reliable long-term adhesion to zirconia.

Purpose: To evaluate the effects of different smear layers on the microtensile bond strength (µTBS) of a reference two-step self-etch adhesive and two universal adhesives.

Materials and methods: Mid-coronal dentin of 90 teeth was exposed and divided into three bur groups (coarse diamond, fine diamond, or tungsten carbide). Each bur-prepared group was further divided into three adhesive groups: Clearfil SE Bond (SE, Kuraray Noritake), Single Bond Universal (SB; 3M Oral Care), and G-Premio Bond (GP, GC). After adhesive application, 4-mm-thick resin composites were built up. Half of the teeth in each bur-adhesive group were used in immediate µTBS testing, and the others were tested after thermal aging (n = 5). Rectangular sticks were prepared using a low-speed diamond saw. For each tooth, 6 central sticks were used in the µTBS test. Statistical analysis was performed using three-way ANOVA and Bonferroni tests (α = 0.05).

Results: SE presented higher µTBS than universal adhesives and SB presented higher µTBS than GP regardless of dentin surface preparation and thermal aging (p ˂ 0.05). For SE and SB, the tungsten carbide bur demonstrated higher immediate and aged µTBS than did the extra-fine diamond bur (p ˂ 0.05). The immediate µTBS was similar for GP with all bur types (p ˃ 0.05); the tungsten carbide and extra-fine diamond burs presented higher µTBS than did the coarse-diamond bur after thermal aging (p ˂ 0.05).

Conclusion: Dentin surface preparation and adhesive type had significant effects on µTBS. The smear layer created with an extra-fine diamond or tungsten carbide bur is favorable when mild and ultra-mild self-etch adhesives are used.

Purpose: To evaluate the effects of different hydrofluoric acid (HF) concentrations and etching times on the surface topography, roughness, and resin bond strength to ceramic-coated zirconia (CC), and to compare them with the effects of alumina air-abrasion combined with 10-MDP (AA).

Materials and methods: AA and CC specimens were divided into 12 groups (N = 10). The CC groups were etched with HF at different concentrations (5% or 9.5%) for various durations (0 min, 1 min, 2 min, 3 min, 5 min or 10 min). The surface morphology was analyzed using SEM. Energy-dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD) were performed for chemical and crystalline-phase analyses. Surface roughness (Ra) and shear bond strength (SBS) were recorded and statistically analyzed.

Results: The SBS of CC groups initially increased, but then decreased with etching time for both HF acid concentrations. The 9.5% HF group displayed more marked topographical changes and higher Ra compared with the 5% HF group for the same etching period. Mean SBS was lower in the AA group compared with the CC groups etched with 5% HF for 2-10 min and 9.5% HF for 1-3 min (p < 0.05).

Conclusions: Different HF concentrations and etching times influenced the surface topography, roughness, and resin bond strength of/to ceramic-coated zirconia. Etching with 5% HF for 5 min and with 9.5% HF for 2 min, respectively, provided the highest SBS.

Purpose: To investigate the effects of plasma surface treatments and methyl methacrylate-based adhesives on polyetheretherketone.

Materials and methods: One hundred ten polyetheretherketone specimens were fabricated and divided into five pretreatment groups: group ArP, 100% argon plasma; group ArOP, 50% argon + 50% oxygen plasma; group ArNP, 50% argon + 50% nitrogen plasma; group ArONP, 75% argon + 12.5% oxygen + 12.5% nitrogen plasma; group C, control. Atomic force microscopy and scanning electron microscopy were performed after surface treatments. After topographical surface examinations, Visio.link primer (Bredent) (n = 10) was applied to the surface of half of the samples in each group (n = 20) and the veneering resin was polymerized onto the polyetheretherketone. The shear bond strengths were measured using a universal test machine.

Results: The mean bond strengths of the Visio.link primer applied to group ArP and group ArONP (13.9 and 13.6 MPa, respectively) were statistically significantly higher than that of group C (9.0 MPa). The average shear bond strength of the Visio.link subgroups was higher than that of the Visio.link subgroups (p > 0.05).

Conclusions: The use of a methyl methacrylate-based adhesive (Visiolink) provides bonding between polyetheretherketone-veneering composites. Different plasma treatments without primer application had no significant effect on bonding.

Purpose: To evaluate the clinical performance of direct composite restorations using nanohybrid and nanofill composite materials in anterior teeth in patients with amelogenesis imperfecta (AI).

Materials and methods: 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.

Results: 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.

Conclusion: 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.