The journal of adhesive dentistry最新文献

Purpose: Evaluation of radicular bond strength and dentinal matrix metalloproteinases (MMPs) activity with different endodontic sealers (traditional vs bioceramic), filling techniques (warm vs cold), and adhesive protocols (self-etch vs etch-and-rinse), after 24 hours and after one year (T0 vs T1).

Materials and methods: 96 extracted, caries-free, single-rooted teeth were selected and shaped with Proglider, ProTaper Next X1-X2. Samples were randomly divided into four groups: warm filling with ZOE sealer; cold filling with resin-based sealer; cold filling with bioceramic sealer; warm filling with bioceramic sealer. After 7 days, a 10 mm post space was prepared using dedicated drills, and each group was divided into two subgroups according to the adhesive procedure (self-etch vs etch-and-rinse, SE vs ER) employed for fiber post cementation with dual resin cement. Samples were analyzed with push-out tests at T0 and T1. 16 additional non-carious multirooted teeth were prepared following the described groups and subgroups for in-situ zymography analysis at T0 and T1. A four-way ANOVA, post-hoc Tukey was used to test the four factors and one-way ANOVA to evaluate the differences within each variable (α = 0.05).

Results: Bioceramic sealer showed significantly higher bond strength than traditional sealer (P 0.05), especially when associated with the warm filling technique. SE adhesive protocol performed significantly better (P 0.05) independently of the sealer used, the filling technique, and the aging time. Greater endogenous collagenolytic activity was identified within the hybrid layer of ER-treated samples compared to SE independently from the other variables tested. In addition, warm technique proved to significantly reduce MMPs activity compared to the cold technique.

Conclusion: The results showed that bioceramic sealers should guarantee better results in radicular dentin bond strength, without altering the endogenous enzymatic activity. The heat produced during the root canal obturation might reduce the internal enzymatic activity but, in association with bioceramic sealers, after 12 months, it produces higher bond strength. Heat reduces the difference between the two adhesive systems. ER technique and aging increase enzymatic activity. Aging tends to increase bond strength, especially in traditional sealers groups associated with ER protocol.

Purpose: The aim of this in-vitro study was to evaluate the effect of different indirect pulp capping (IPC) materials on bond strength to surrounding dentin.

Materials and methods: Fifty-six human third molars were used in this study. Occlusal dentin of 42 teeth was exposed. Dentin surfaces (n = 6) were left uncovered (control) or received a 1 × 1 mm central IPC (KL: Kerr life, DY: Dycal, TC: Theracal LC, CL: Calcimol LC, BD: Biodentine, and PR: ProRoot MTA) and were then bonded with Scotchbond Universal adhesive and restored with a composite resin build-up (Filtek™ Z250). After 24 h of water storage, the specimens were cut into sticks, which were marked red (1 mm distance from IPC spot), green (2 mm distance), and blue (3 mm distance). Consequently, µ-TBS tests were performed and analyzed using one-way ANOVA (P 0.05) for normal distributions and Mann-Whitney U-test (P 0.05) for non-normal distributions. Pretesting failures were recorded as 0 MPa. Fracture modes were analyzed under a fluorescence microscope, and interfaces and surfaces of 14 additional specimens were visualized under a scanning electron microscope (SEM).

Results: A significant reduction in peripheral seal was only observed for KL (Mann-Whitney U-test, P 0.05). All groups showed increasing bond strengths from the IPC area to the periphery, indicating a certain contamination potential of IPC materials.

Conclusion: IPC materials being applied in very deep cavity areas except Kerr Life do not harm peripheral seal to dentin. Especially, hydraulic cements can be used without a negative effect on the peripheral dentin seal.

Purpose: To investigate, via questionnaire, how protocols for adhesive luting workflows of dental restorations are applied in three German-speaking countries.

Material and methods: A 47-item questionnaire gathered data on airborne particle abrasion (APA) unit characteristics, parameters, operating procedures, pretreatments in adhesive luting workflows for restorations, and participant demographics. The survey was distributed via trade journals, expert associations, universities, technical schools, and social media. Marginal absolute and relative frequencies were analyzed (95% confidence intervals), with Chi-squared tests comparing observed and expected frequencies (P0.05). Twenty-three experts voted on 23 recommendations regarding APA parameters and other pretreatments for bonding restorations.

Results: A total of 267 participants completed the survey. Access to an APA unit was linked to a higher likelihood of performing APA before placement. Approximately half of the participants used APA in their practice. For zirconia restorations, 47.2% applied alumina APA at 50 µm/0.1 MPa, while 36.7% used the same settings for polymer-based restorations. For alloys, 37.5% employed 110 µm/0.2 MPa. These preferences correlated with age (≥30 years), experience (≥10 years), profession (dental technician/dentist), prior instruction/training, and daily APA use. Adhesives with MDP were used for zirconia (63.8%) and those with silane for silicate-based ceramics (55.9%). Agreement on recommendations ranged between 52% and 100%, with 21/23 reaching an average of 93%.

Conclusion: Access to APA influenced clinical decisions and the feasibility of adhesive luting workflows. Adequate APA equipment in dental facilities is essential for quality care. Standardized protocols, training, and education across dental professions are necessary to enhance understanding and proper use of APA.

Purpose: To evaluate the effect of a self-etching primer on the long-term bond strength stability between a leucite-based glass-ceramic and resin cement, compared to the conventional treatment involving hydrofluoric acid (HF) etching followed by silane application.

Materials and methods: Blocks of a leucite-based glass-ceramic (IPS Empress CAD) were cut into plates and embedded in acrylic resin. Half of the specimens were treated with 5% HF for 60 s and silane application, and the other half was treated with a self-etching primer (Monobond Etch and Prime, MEP). Resin cement cylinders (n = 24) were built onto their surfaces, and the specimens of each group were divided into three subgroups according to the microshear bond strength (µSBS) testing time: baseline, after 10,000 thermocycles, or after 10,000 thermocycles followed by 180 days of immersion in water. Statistical analysis was performed with two-way analysis of variance and Tukey's tests. Complementary failure mode, contact angle, and scanning electron microscopy analyses were carried out.

Results: MEP groups showed higher bond strength results than HF. HF-treated specimens exhibited a decrease in bond strength after thermocycling and water storage, while MEP-treated specimens maintained similar bond strength values across all aging conditions. Only cohesive failures within the ceramic were observed at baseline. After aging, most HF specimens exhibited adhesive failures. HF etching created more irregularities with apparent deeper defects on the ceramic surface compared to MEP. HF etching produced a lower contact angle between the ceramic surface and the water drop compared to the self-etching primer.

Conclusion: Applying the self-etching primer resulted in higher bond strength stability between leucite-based glass-ceramic and resin cement compared to conventional treatment.

Purpose: This study aims to develop and characterize copper-doped bioactive glass nanoparticles (BG/CuNp), and to evaluate the effects of their addition into a resin composite on antimicrobial activity (AMA), cytotoxicity (CTX), ultimate tensile strength (UTS), Knoop microhardness (KHN), as well as immediate resin-dentin microtensile bond strength (μTBS), nanoleakage (NL) and in-situ degree of conversion (DC).

Materials and methods: BG/CuNp were added to a resin composite at different concentrations (0% [control]; 5, 10 and 20 wt%). The AMA was evaluated against Streptococcus mutans. For CTX, the Gingival mesenchymal stem cells (GMSC) cell line was used. For UTS and KHN, specimens were tested after 24 h and 28 days. For bonding evaluation, a universal adhesive was applied on flat dentin surfaces, experimental resin composite build-ups were prepared, and specimens were sectioned to obtain resin-dentin sticks. These were evaluated for μTBS, NL and DC after water storage. Data were submitted to statistical analyses (α = 0.05).

Results: The addition of 5% and 10% of BG/CuNp increases AMA (P 0.05), while the CTX remained unchanged with resin-containing BG/CuNp (P > 0.05). UTS and KHN remained stable with the addition of 5% and 10% of BG/CuNp at 24 h, but showed significantly higher values compared to the control after 28 d (P 0.05). μTBS and in-situ DC remained unchanged with BG/CuNp addition, regardless of the concentration added. However, significantly lower NL was observed for BG/CuNp groups (P 0.05).

Conclusion: The addition of BG/CuNp in the tested concentrations into a resin composite may be an alternative to provide antimicrobial activity and improve the integrity of the hybrid layer, without compromising biological, adhesives and mechanical properties.

Purpose: Considering the significant weakening of the bonding of resin cements to saliva-contaminated zirconia restorations, this study aimed to investigate the effect of various surface treatment methods on the bonding of self-adhesive resin cement to zirconia after various cleansing methods.

Material and methods: A total of 105 monolithic zirconia specimens were cut from pre-sintered blocks using a water-cooled precision diamond saw. Specimens were kept in the artificial saliva except for the control group. The specimens were then cleaned using one of the following methods: 1. Air-water spray, 2. Isopropyl Alcohol, 3. Pumice, 4. Universal cleaning agent (Ivoclean), 5. Sandblasting, 6. Sandblasting + Ivoclean. Specimens were bonded to self-adhesive resin cement. Specimens were thermocycled for 5,000 cycles after cementation and tested in shear mode (1 mm/min). Images were obtained using a stereomicroscope, scanning electron microscope, and energy-dispersive spectroscopy. Data were analyzed using ANOVA, and multiple comparisons were performed with the Duncan test (α = 0.05).

Results: The mean shear bond strength values were as follows in descending order: Sandblasting + Ivoclean (9.3 MPa) > sandblasting (8.59 MPa) > Ivoclean (7.21 MPa) > Pumice (4.82 MPa) > Air-water spray (4.15 MPa) > Control (3.65 MPa) > Isopropyl alcohol (3.04 MPa). Significant difference was observed between sandblasting and Ivoclean groups, and between sandblasting and sandblasting + Ivoclean groups (P 0.05). A significant difference was also found between the Ivoclean and sandblasting + Ivoclean groups. The groups treated with sandblasting + Ivoclean, sandblasting, and Ivoclean showed a significant difference compared to all other surface treatment groups. There was no significant difference in shear bond strength among the control, air-water, alcohol, and pumice groups (P > 0.05). Sandblasting, Ivoclean, and Ivo-clean after sandblasting applications were found to deliver significantly higher (P 0.05) adhesion compared with air-water, pumice, and alcohol applications.

Conclusions: Subsequent applications of Ivoclean after sandblasting established a stronger bond between self-adhesive resin cement and monolithic zirconia than other cleaning methods tested.

Clinical implications: Following airborne particle abrasion, intaglio surfaces of zirconia restorations should best be cleaned using Ivoclean.

Purpose: Evaluation of different composites with varying viscosity for their suitability as intracanal anchorage (ICA) materials using push-out bond strength testing.

Materials and methods: 48 human maxillary incisors were root filled, crowns partially removed except one residual wall, and distributed into four groups (n = 12), according to one of the following ICA composites: Ormocer (AFx), preheated composite (VB), core build-up (RDC) or flowable (SDR). A 4 mm deep root canal enlargement was prepared using Gates Glidden burrs, and hard tissues were conditioned using a universal adhesive in etch-and-rinse mode. Intracanal cavities were filled using the groups' specific ICA material and a nanohybrid composite (GrandioSO, VOCO) for crown reconstruction. Two samples per group were scanned using phase-contrast-enhanced µ-computer tomography (PCE-CT). The remaining samples were thermo-mechanically loaded (TML), and push-out bond strengths and fracture patterns of ICA materials were analyzed.

Results: Push-out bond strengths were significantly affected by ICA materials (P = 0.001) and location inside the root canal (P 0.005; generalized estimating equations). VB showed a significantly lower bond strength (13.5MPa ± 5.3MPa) compared to RDC (19.6MPa ±7.6MPa) and AFx (21.4MPa ±7.6MPa), but did not differ significantly from SDR (20MPa ± 10.3MPa). All groups demonstrated predominantly adhesive failures between the composite and dentin (P 0.05; Chi-square test). µ-CT scans indicate material-dependent localization and quantity of voids.

Conclusion: The survival rates after TML and the push-out bond strength values indicate a sufficient bonding of all ICA materials. Frequently occurring voids highlight problems of application and the effects of materials' viscosity on void formation and bond strength.

Purpose: To investigate the effect of tooth age on dentin adhesion of different luting systems to the root canal.

Materials and methods: 180 root canals of extracted teeth were divided into three age-specific groups (n = 60): young 20-35 (y), middle-aged 45-60 (m), and older 70-85 (o) years. Ten teeth of each age group were assigned to a luting system: Panavia 21 with ED Primer (P21, Kuraray); Core X Flow with Prime&Bond active and Self-Cure Activator (CXF, Dentsply Sirona); Multilink Automix with Multilink Primer (ML, Ivoclar Vivadent); Panavia SA Cement Plus (PSA, Kuraray); Smart Cem 2 (SM2, Dentsply Sirona); Speed CEM Plus (SCP, Ivoclar Vivadent). The root canals of decoronated teeth were instrumented with F360 (Komet) and BR7 (FKG) up to a working length of 8 mm (Ø0.6mm, taper 0.02) and filled with standardized steel spreaders and the selected material. The intracanal bond was determined by a pull-out test. The failure modes were categorized as an adhesive to dentin (AD), adhesive to spreader (AS), cohesive within the composite (C), and mixed (M). Statistical analysis was performed using non-parametric ANOVA, Tukey, and Chi-square test at a significance level of α ≤ 0.05.

Results: The study showed significant differences for the various luting systems (ANOVA, P 0.05). PSA showed significant differences in bond strength to SM2, CXF, SCP, and ML, as did SM2 to P21 and SCP (Tukey, P 0.05). M (46%) occurred 53% in y and 70% in SCP.

Conclusions: No adhesive strategy can yet be recommended for tooth age. Clinically available luting systems show significant differences in their adhesion values.

Purpose: This in-vitro study evaluated the effect of universal adhesives and sandblasting with 50 μm and 110 μm aluminum oxide particles (Al2O3) on the shear bond strength (SBS) between composite and zirconia in repair applications across different aging intervals.

Materials and methods: 1296 zirconia specimens (Katana Zirconia HT) were randomized into three main groups: (A) sandblasting with 50 μm Al2O3, (B) sandblasting with 110 μm Al2O3, and (C) control. Each group was further divided into six subgroups: OPB (Optibond Universal), PBA (Prime&Bond Active), IBU (iBond Universal), CUBQ (Clearfil Universal Bond Quick), MBP (Monobond Plus), and SBUP (Scotchbond Universal Plus). Composite (Clearfil Majesty ES-2 Universal) was applied, and SBS (MPa) measured at baseline (24-h storage) at 30 and 90 days, and after 7 days + 5000 thermocycles (5-55°C). Failure modes were assessed at 40 × magnification. Analysis used a generalized linear model (GLM) with Bonferroni adjustment (α 0.05).

Results: Sandblasting significantly increased SBS compared to controls, with Group B showing the highest durability after thermocycling, with values decreasing over aging periods. In Groups A and B IBU (21.43 ± 2.7 MPa; 25.60 ± 5.78 MPa), SBUP (19.26 ± 3.2 MPa; 23.62 ± 4.4 MPa), and CUBQ (19.92 ± 2.8 MPa; 22.75 ± 4.34 MPa) achieved the highest SBS, with adhesive failures being predominant and cohesive failures mainly in high-SBS subgroups.

Conclusion: Pretreatment with Al2O3 significantly enhances composite-zirconia bond strength, with larger grit sizes more effective. MDP-containing adhesives are recommended for reliable zirconia repairs.

Purpose: The study aimed to measure the efficacy of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) saliva-decontamination protocols by measuring bonding effectiveness to saliva-contaminated dentin following different surface-decontamination protocols.

Materials and methods: The micro-tensile bond strength (µTBS) of the two-step self-etch (SE) adhesive Clearfil SE Bond 2 ('CSE2', Kuraray Noritake) and the one-step SE adhesive Clearfil Universal Bond Quick ('CUBQ', Kuraray Noritake) to saliva-contaminated bur-cut dentin was measured when saliva-contaminated dentin was decontaminated by either the 10-MDP-containing Katana Cleaner ('KC', Kuraray Noritake) or CSE2 primer ('CSE2p'), with bonding to saliva-contaminated ('saliva(-)') and non-contaminated dentin ('clean(+)') having served as negative and positive control, respectively. Half of the specimens were subjected to µTBS testing 'immediately' after 1-week water storage, while the other 'aged' half was tested after 50,000 thermocycles. Statistics involved linear mixed modeling (LMM) with restricted maximum likelihood (REML) estimation (α = 0.05).

Results: Overall, the two-step SE adhesive CSE2 outperformed the one-step SE adhesive CUBQ. Saliva-contaminated dentin was most effectively decontaminated when CSE2p was applied with both adhesives, closely followed by KC decontamination. Notably, CSE2 demonstrated satisfactory performance even without separate decontamination.

Conclusion: Unaltered bonding to saliva-contaminated dentin was achieved upon surface decontamination with CSE2p and KC. Using CUBQ, additional decontamination with either CSE2p or KC is strongly recommended. In the case of CSE2, no additional decontamination agent is required.