The effect of composite placement technique on the internal adaptation, gap formation  and microshear bond strength

SUMMARY Objectives: The aim of this study was to investigate the effect of different protocols of 17% ethylene diamine tetra-acetic acid (EDTA) conditioning on the etching pattern and immediate bond strength of universal adhesives to enamel and sclerotic dentin. Methods and Materials: Forty bovine teeth with sclerotic dentin and 20 human third molars were randomly divided into eight groups resulting from the combination of the main factors surface treatment (none, two-minute EDTA conditioning manual application, 30-second EDTA manual application, 30-second EDTA sonic application) and adhesives systems (Scotchbond Universal Adhesive [SBU] and Prime & Bond Elect [PBE]). Resin-dentin and enamel-dentin bond specimens were prepared and tested under the microtensile bond strength (μTBS) and microshear bond strength (μSBS) tests, respectively. The etching pattern produced on the unground enamel and the sclerotic dentin surfaces under the different protocols and adhesive systems was evaluated under scanning electron microscopy. Results: For enamel, only the main factor adhesive was significant (p<0.0001), with SBU showing the highest μSBS. In sclerotic dentin, the lowest mean was observed for the group without EDTA application and the highest mean in the group with EDTA application with the sonic device for 30 seconds. Regardless of the EDTA protocol, the highest means of μTBS were observed for SBU (p<0.05). Conclusions: EDTA conditioning improves the bonding performance of universal adhesives in the self-etch mode on sclerotic dentin, mainly when applied for 30 seconds with the aid of a sonic device. EDTA pretreatment also improves the retentive etching pattern of enamel, but it does not result in higher enamel bond strength.

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Effect of topical fluoride on microshear bond strength of primary enamel to composite, microhardness of enamel and its surface morphology: An in vitro study

Journal of Dental Research Dental Clinics Dental Prospects ◽

10.15171/joddd.2019.046 ◽

2019 ◽

Vol 13 (4) ◽

pp. 305-310

Author(s):

Mina Biria ◽

Sajedeh Namaei Ghasemi ◽

Seyedeh Mahsa Sheikh-Al-Eslamian ◽

Narges Panahandeh

Keyword(s):

Bond Strength ◽

Artificial Saliva ◽

Morphological Characteristics ◽

In Vitro Study ◽

Vitro Study ◽

Control Group ◽

Modes Of Failure ◽

Group 3 ◽

Microshear Bond Strength

Background. This in vitro study aimed to evaluate the microshear bond strength (μSBS), microhardness and morphological characteristics of primary enamel after treating with sodium fluoride (NaF) and acidulated phosphate fluoride (APF). Methods. Forty-eight primary canines were cut into mesial and distal sections and assigned to five groups randomly: group 1 (immersed in saliva as a control), group 2 (treated with NAF and immersed in saliva for 30 minutes), group 3 (treated with APF and immersed in saliva for 30 minutes), group 4 (treated with NAF and immersed in saliva for 10 days), and group 5 (treated with APF and immersed in saliva for 10 days). Composite resin (Filtek Z250) was bonded on the specimens (n=15) for measuring the μSBS. After storage in 37°C artificial saliva for 24 hours, µSBS and Vickers hardness tests (10 readings) were performed. The data were analyzed using one-way ANOVA and Kolmogorov-Smirnov, Levene’s and Tukey HSD tests (P<0.05). Morphological analysis of enamel and modes of failure were carried out under a scanning electron microscope (SEM) on two remaining specimens. Results. Significant differences in μSBS were only noted between groups 2 and 4 (P=0.024). Group 3 showed a significant decrease in hardness after storage in artificial saliva (P<0.001), with a significantly lower hardness than the other groups (P<0.001). The SEM observations showed irregular particles in groups 3 and 5; uniform, smooth and thin coats were seen in groups 2 and 4. Conclusion. Fluoride therapy with NaF and APF gels prior to restorative treatments had no adverse effects on the microshear bond strength.

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Effect of surface treatments on repair strength, roughness and morphology in aged metal-free crowns

Brazilian Journal of Oral Sciences ◽

10.20396/bjos.v19i0.8656155 ◽

2020 ◽

Vol 19 ◽

pp. e206155

Author(s):

Yançanã Luizy Gruber ◽

Thaís Emanuelle Bakaus ◽

Bruna Fortes Bittencourt ◽

João Carlos Gomes ◽

Alessandra Reis ◽

...

Keyword(s):

Bond Strength ◽

Surface Treatment ◽

Adhesive System ◽

Surface Treatments ◽

Metal Free ◽

Diamond Bur ◽

Before And After ◽

Post Test ◽

Microshear Bond Strength

Aim: The roughness and micromorphology of various surface treatments in aged metal-free crowns and the bond strength of these crowns repaired with composite resin (CR) was evaluated in vitro. Methods: A CR core build-up was confectioned in 60 premolars and prepared for metal-free crowns. Prepared teeth were molded with the addition of silicone, and the laboratory ceromer/fiber-reinforced crowns (SR Adoro/Fibrex Lab) were fabricated. Subsequently, the crowns were cemented and artificially aged in a mechanical fatigue device (1.2 X 106 cycles), then divided into 4 groups (n = 15) according to the surface treatment: 1) phosphoric acid etching (PA); 2) PA + silane application; 3) roughening with a diamond bur + PA; and 4) sandblasting with Al2O3 + PA. After the treatments, the crowns (n = 2) were qualitatively analyzed by scanning electron microscope (SEM) and surface roughness (n = 5) was analyzed before and after the surface treatment (Ra parameter). The remaining crowns (n = 8) received standard repair with an adhesive system (Tetric N-Bond) and a nanohybrid CR (Tetric N-Ceram), and the microshear bond strength (SBS) test was performed (0.5 mm/min). Roughness and SBS data were analyzed by one- and two-way ANOVA, respectively, as well as Tukey’s post-test (α = 0.05). Results: Sandblasting with Al2O3 + PA resulted in the highest final roughness and SBS values. The lowest results were observed in the PA group, whereas the silane and diamond bur groups showed intermediate values. Conclusion: It may be concluded that indirect ceromer crowns sandblasted with aluminum oxide prior to PA etching promote increased roughness surface and bond strength values.

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Effects of Multipurpose, Universal Adhesives on Resin Bonding to Zirconia Ceramic

Operative Dentistry ◽

10.2341/13-303-l ◽

2015 ◽

Vol 40 (1) ◽

pp. 55-62 ◽

Cited By ~ 37

Author(s):

J-H Kim ◽

S-Y Chae ◽

Y Lee ◽

G-J Han ◽

B-H Cho

Keyword(s):

Bond Strength ◽

Artificial Aging ◽

Resin Cement ◽

Zirconia Ceramic ◽

Single Bond ◽

Surface Conditioning ◽

Universal Adhesives ◽

Bond Strengths ◽

Microshear Bond Strength ◽

Composite Cylinders

SUMMARY This study evaluated the effects of single-bottle, multipurpose, universal adhesives on the bond strength of resin cement to zirconia ceramic. Polished zirconia ceramic (Cercon base) discs were randomly divided into four groups (n=40) according to the applied surface-conditioning agent: Single Bond 2, Single Bond Universal, All-Bond Universal, and Alloy Primer. Cured composite cylinders (Ø 0.8 mm × 1 mm) were cemented to the conditioned zirconia specimens with resin cement (RelyX ARC). The bonded specimens were subjected to a microshear bond-strength test after 24 hours of water storage and after 10,000 cycles of thermocycling. The surface-conditioning agent significantly influenced the bond strength (p<0.05). Single Bond Universal showed the highest initial bond strength (37.7 ± 5.1 MPa), followed by All-Bond Universal (31.3 ± 5.6 MPa), Alloy Primer (26.9 ± 5.1 MPa), and Single Bond 2 (8.5 ± 4.6 MPa). Artificial aging significantly reduced the bond strengths of all the test groups (p<0.05). After 10,000 cycles of thermocycling, All-Bond Universal showed the highest bond-strength value (26.9 ± 6.4 MPa). Regardless of artificial aging, Single Bond Universal and All-Bond Universal showed significantly higher bond strengths than Alloy Primer, a conventional metal primer.

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Lack of Neutralization of 10-MDP Primers by Zirconia May Affect the Degree of Conversion of Dual-cure Resin Cement

Operative Dentistry ◽

10.2341/18-189-l ◽

2021 ◽

Vol 46 (1) ◽

pp. 107-115

Author(s):

DM De Paula ◽

AD Loguercio ◽

A Reis ◽

S Sauro ◽

AH Alves ◽

...

Keyword(s):

Bond Strength ◽

Testing Machine ◽

Monomer Concentration ◽

Positive Control ◽

Degree Of Conversion ◽

Resin Cement ◽

Dihydrogen Phosphate ◽

Resin Cements ◽

Low Concentrations ◽

Microshear Bond Strength

Clinical Relevance Use of zirconia primers with a low pH and a high acidic monomer concentration should be employed in combination with dual-cure resin cements that are less sensitive to an acidic environment. Primers with lower 10-MDP concentrations attain better outcomes. SUMMARY Objective: To assess the effects of different concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) included in experimental ceramic primers on the degree of conversion (DC) and microshear bond strength (μSBS) of a dual-cure resin cement, and on the acidity neutralization potential of zirconia (ZrO2) in comparison to hydroxyapatite (HAp). Methods: Experimental ceramic primers were formulated using 5 wt%, 10 wt%, 20 wt%, or 40 wt% 10-MDP as an acidic functional monomer and camphorquinone (CQ)/amine or 1-phenyl-1,2-propanedione (PPD) as a photoinitiator system. Clearfil Ceramic Primer (Kuraray Dental, Tokyo, Japan) was used as the commercial control. Micro-Raman spectroscopy was used to assess the DC of uncured and light-cured resin cements applied onto primer-treated ZrO2 surfaces. The μSBS and pH of primers were assayed in a universal testing machine and by a digital pH meter (Tec-3MP; Tecnal, Piracicaba, Brazil), respectively. Statistical analysis was performed by one-way analysis of variance (ANOVA) and Tukey’s test (p<0.05). Results: DC was not affected until a concentration of 10% 10-MDP in CQ primer and 5% 10-MDP in PPD primer was reached, when compared with the positive control (p>0.05). Groups 10-MDP 5% in CQ and PPD primers showed the highest μSBS compared with the positive control (p>0.05); however, higher concentrations of 10-MDP induced significant DC and μSBS reduction (p<0.05). HAp neutralized 10-MDP primers, but ZrO2 provided higher acidity to the primers’ pH. Conclusion: 10-MDP monomer should be used in low concentrations in ZrO2 primers to avoid reduction of the polymerization and bond strength of resin cement.

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Triacrylamide-Based Adhesives Stabilize Bonds in Physiologic Conditions

Journal of Dental Research ◽

10.1177/00220345211061736 ◽

2022 ◽

pp. 002203452110617

Author(s):

F.S. de Lucena ◽

S.H. Lewis ◽

A.P.P. Fugolin ◽

A.Y. Furuse ◽

J.L. Ferracane ◽

...

Keyword(s):

Bond Strength ◽

Cross Sections ◽

Laser Scanning ◽

Adhesive System ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Gap Formation ◽

Bond Stability ◽

Occlusal Surfaces ◽

Before And After

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey’s test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

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Influence of a propolis-based irrigant solution on gap formation and bond strength of posts bonded to root canal dentin using different resin cements

Dental Materials Journal ◽

10.4012/dmj.2019-111 ◽

2020 ◽

Vol 39 (3) ◽

pp. 490-499

Author(s):

Marcelo Henrick Maia MATOCHEK ◽

Pedro Luiz Santos TOMAZ ◽

Thales de Sá OLIVEIRA ◽

Mackeler Ramos POLASSI ◽

Roberta Caroline Bruschi ALONSO ◽

...

Keyword(s):

Bond Strength ◽

Root Canal ◽

Gap Formation ◽

Resin Cements ◽

Root Canal Dentin

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The effect of fusion sputtering surface treatment on microshear bond strength of zirconia and MDP-containing resin cement

Dental Materials ◽

10.1016/j.dental.2019.02.013 ◽

2019 ◽

Vol 35 (6) ◽

pp. e107-e112 ◽

Cited By ~ 2

Author(s):

Nesma Ali ◽

Ahmed Safwat ◽

Moustafa Aboushelib

Keyword(s):

Bond Strength ◽

Surface Treatment ◽

Resin Cement ◽

Microshear Bond Strength

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In Vitro Study on the Effect of a New Bioactive Desensitizer on Dentin Tubule Sealing and Bonding

Journal of Functional Biomaterials ◽

10.3390/jfb11020038 ◽

2020 ◽

Vol 11 (2) ◽

pp. 38

Author(s):

Minh N. Luong ◽

Laurie Huang ◽

Daniel C. N. Chan ◽

Alireza Sadr

Keyword(s):

Bond Strength ◽

In Vitro Study ◽

Vitro Study ◽

Acid Pretreatment ◽

Universal Adhesive ◽

Cross Sectional ◽

Before And After ◽

Human Dentin ◽

Microshear Bond Strength

Bioactive mineral-based dentin desensitizers that can quickly and effectively seal dentinal tubules and promote dentin mineralization are desired. This in vitro study evaluated a novel nanohydroxyapatite-based desensitizer, Predicta (PBD, Parkell), and its effect on bond strength of dental adhesives. Human dentin discs (2-mm thick) were subjected to 0.5 M EDTA to remove the smear layer and expose tubules, treated with PBD, and processed for surface and cross-sectional SEM examination before and after immersion in simulated body fluid (SBF) for four weeks (ISO 23317-2014). The effects of two dental desensitizers on the microshear bond strength of a universal adhesive and a two-step self-etch system were compared. SEM showed coverage and penetration of nanoparticles in wide tubules on the PBD-treated dentin at the baseline. After four weeks in SBF, untreated dentin showed amorphous mineral deposits while PBD-treated dentin disclosed a highly mineralized structure integrated with dentin. Desensitizers significantly reduced microshear bond strength test (MSBS) of adhesives by 15–20% on average, depending on the bonding protocol. In conclusion, PBD demonstrated effective immediate tubules sealing capability and promoted mineral crystal growth over dentin and into the tubules during SBF-storage. For bonding to desensitizer-treated dentin, a two-step self-etching adhesive or universal bond with phosphoric acid pretreatment are recommended.

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