Effect of Artificial Aging and Surface Treatment on Bond Strengths to Dental Zirconia

2013 ◽  
Vol 38 (2) ◽  
pp. 168-176 ◽  
Author(s):  
J Perdigão ◽  
SD Fernandes ◽  
AM Pinto ◽  
FA Oliveira
Keyword(s):  
Surface Treatment ◽  
Artificial Aging ◽  
Testing Machine ◽  
Significance Level ◽  
Diamond Blade ◽  
Universal Testing ◽  
Bond Strengths ◽  
The Mean ◽  
Post Hoc ◽  
Adhesive Cement

SUMMARY The objective of this project was to study the influence of artificial aging and surface treatment on the microtensile bond strengths (μTBS) between zirconia and a phosphate monomer–based self-adhesive cement. Thirty zirconia disks (IPS e.max ZirCAD, Ivoclar Vivadent) were randomly assigned to two aging regimens: AR, used as received, which served as a control, and AG, artificial aging to simulate low-temperature degradation. Subsequently, the disks of each aging regimen were assigned to three surface treatments: NT, no surface treatment; CO, surface silicatization with CoJet sand (3M ESPE); and ZP, zirconia surface treated with Z-Prime Plus (Bisco Inc). Thirty discs were made of Filtek Z250 (3M ESPE) composite resin and luted to the zirconia discs using RelyX Unicem (3M ESPE). The specimens were sectioned with a diamond blade in X and Y directions to obtain bonded beams with a cross-section of 1.0 ± 0.2 mm. The beams were tested in tensile mode in a universal testing machine at a speed of 0.5 mm/min to measure μTBS. Selected beams were selected for fractographic analysis under the SEM. Statistical analysis was carried out with two-way analysis of variance and Dunnett T3 post hoc test at a significance level of 95%. The mean μTBS for the three AR subgroups (AR-NT, AR-CO, and AR-ZP) were significantly higher than those of the corresponding AG groups (p<0.0001). Both AR-CO and AR-ZP resulted in statistically significant higher mean bond strengths than the group AR-NT (p<0.006 and p<0.0001, respectively). Both AG-CO and AG-ZP resulted in statistically significant higher mean bond strengths than the group AG-NT (both at p<0.0001). Overall, AG decreased mean μTBS. Under the SEM, mixed failures showed residual cement attached to the zirconia side of the beams. CO resulted in a characteristic roughness of the zirconia surface. AR-ZP was the only group for which the amount of residual cement occupied at least 50% of the interface in mixed failures.

scholarly journals Push-out bond strength of different mineral trioxide aggregates

2014 ◽  
Vol 08 (03) ◽  
pp. 348-352 ◽  
Author(s):  
Huseyin Ertas ◽  
Ebru Kucukyilmaz ◽  
Evren Ok ◽  
Banu Uysal
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Mineral Trioxide Aggregate ◽  
Human Teeth ◽  
Universal Testing ◽  
Significant Difference ◽  
Bond Strengths ◽  
The Mean ◽  
Post Hoc ◽  
Push Out

ABSTRACT Objective: This study was aimed to evaluate and to compare the push-out bond strength of different brands of mineral trioxide aggregate (MTA) with a calcium enriched mixture cement (CEM). Materials and Methods: Fifteen extracted, single-rooted human teeth were used. The middle-third of the roots were sliced perpendicular to the long axis into 1.00 ± 0.05 mm thick serial slices (15 root × 4 slice = 60 specimen). The specimens were then divided into three groups (n = 20). The standardized root discs were filled with white CEM, ProRoot MTA, MTA-Angelus and wrapped in a serum-soaked gauze. After 3 days at relative humidity, the push-out bond strengths were measured with a universal testing machine. Data were analyzed using one-way analysis of variance and post hoc Tukey tests. Results: The mean push-out bond strength value of the ProRoot MTA group (12.7 ± 2.5 MPa) was the highest and statistically significant difference was recorded between ProRoot MTA and other groups (P < 0.001). There was no significant difference between the mean bond strength of CEM cement (4.6 ± 1.1 MPa) and MTA-Angelus (4.5 ± 1.5 MPa) (P = 0.982). Conclusion: The push-out bond strength of MTA was changed with the brands and ProRoot MTA had the highest push-out bond strength.

scholarly journals Effects of various liquid-to-powder ratios on the compressive strength of calcium enriched mixture: Original research

2021 ◽  
Vol 15 (2) ◽  
pp. 129-132
Author(s):  
Mohammad Forough Reyhani ◽  
Sheida Hosseinian Ahangarnezhad ◽  
Negin Ghasemi ◽  
Amin Salem Milani
Keyword(s):  
Compressive Strength ◽  
Testing Machine ◽  
Original Research ◽  
Significance Level ◽  
Cem Cement ◽  
Universal Testing ◽  
Demineralized Water ◽  
Compressive Strength Test ◽  
The Mean ◽  
One Way Anova

Background. Calcium-enriched mixture (CEM) cement has been introduced and marketed as a biomaterial for use in furcal perforation repair and apexogenesis procedures, in which the compressive strength that indicates the material’s resistance against crushing is of utmost importance. This study evaluated the effect of various liquid-to-powder ratios on CEM cement’s compressive strength. Methods. One gram of the cement was mixed with 0.5, 0.34, and 0.25 mL of demineralized water and transferred to stainless steel molds (6 and 4 mm in height and diameter, respectively). Five cells in the mold were considered for each group. The compressive strength test was conducted using the universal testing machine after incubating for seven days under 95% humidity at 37°C. One-way ANOVA was applied for data analysis at P≤0.05 significance level. Results. The mean compressive strength in the liquid-to-powder ratios of 0.5, 0.34, and 0.25 were 3.4456, 3.2960, and 3.3485, respectively, with no significant differences between them. Conclusion. Under this study’s limitations, changing the liquid-to-powder ratio did not affect CEM cement’s compressive strength.

scholarly journals In situ evaluation of orthodontic elastomeric chains

2012 ◽  
Vol 23 (4) ◽  
pp. 394-398 ◽  
Author(s):  
Carolina Baratieri ◽  
Cláudia Trindade Mattos ◽  
Matheus Alves Jr ◽  
Thiago Chon Leon Lau ◽  
Lincoln Issamu Nojima ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Testing Machine ◽  
Time Factors ◽  
Time Interval ◽  
Significance Level ◽  
Universal Testing ◽  
Initial Force ◽  
Post Hoc ◽  
Elastomeric Chains

The hypothesis tested in this study was that intraoral exposure of elastomeric chains alters their tensile strength. For such purpose, it was evaluated the in situ behavior of different elastomeric chains stretched for 3 weeks. Three kinds of elastomeric chains, Plastic chain (PC), Memory chain (MC) and Super slick chain (SSC), were randomly placed in 3 quadrants of 13 patient in a fixed distance of 16 mm and mean initial force of 180 g. Tensile testing was performed in an universal testing machine at different intervals: initial, 1 h, 24 h, 1 week, 2 weeks and 3 weeks. A two-way ANOVA test was performed to identify the influence of both material and time on the force decrease. A subsequent one-way ANOVAtest with the Tukey's post hoc test was used to identify statistically significant intragroup and intergroup remaining force (g and %) differences at 5% significance level. The effect of both the material and the time factors were significant. All groups showed significant force decrease after the 1-h period (23% for PC and 14% for MC and SSC). At the end of the 3-week period, the remaining force was 57% (96 g), 67% (129 g) and 71% (125 g) for PC, MC and SSC, respectively. In conclusion, intraoral exposure of elastomeric chains altered their tensile strength. In general, the greater force decrease occurred within the first hour. The remaining force of the enhanced chains measured at each time interval was greater than the conventional one (PC). After 3 weeks, only the enhanced chains maintained the force applied over 100 g.

Effect of Steam Autoclaving on the Tensile Strength of Resin Cements Used for Bonding Two-Piece Zirconia Abutments

2017 ◽  
Vol 43 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Marcos Alexandre Fadanelli ◽  
Flávia Lucisano Botelho do Amaral ◽  
Roberta Tarkany Basting ◽  
Cecilia Pedroso Turssi ◽  
Bruno Salles Sotto-Maior ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Testing Machine ◽  
Resin Cement ◽  
The Other ◽  
Strength Testing ◽  
Resin Cements ◽  
Universal Testing ◽  
Cad Cam ◽  
The Mean ◽  
Adhesive Cement

The purpose of this study was to evaluate the effects of steam autoclave sterilization on the tensile strength of two types of resin cements used to bond customized CAD/CAM zirconia abutments onto titanium bases. Forty sets of zirconia abutments cemented to screwed titanium bases of implants analogs were divided into 4 groups (n = 10). Two groups were treated with a conventional chemically activated resin cement (ML, Multilink Ivoclar Vivadent) and the other two groups with a self-adhesive dual resin cement (RelyX U200, 3M ESPE). One group from each cement was submitted to steam autoclaving. The autoclave sterilization cycle was performed after 72 hours of cementation for 15 minutes at 121°C and 2.1 Kgf/cm2. The samples were subjected to tensile strength testing in a universal testing machine (200 Kgf, 0.5 mm/min), from which the means and standard deviations were obtained in Newtons. Results showed (via ANOVA and Tukey's test; α = 0.05) that in the absence of steam autoclaving, no difference was observed in tensile strength between the cements tested: ML: 344.87 (93.79) and U200: 280 (92.42) (P = .314). Steam autoclaving, however, significantly increased tensile strength for the ML: 465.42 (87.87) compared to U200: 289.10 (49.02) (P &lt; .001). Despite the significant increase in the ML samples (P = .013), autoclaving did not affect the tensile strength of the U200 samples (P &gt; 0.05). The authors concluded that steam autoclaving increases the mean tensile strength of the chemically activated cement compared to the dual-cure self-adhesive cement. The performance of both cements evaluated was similar if the sterilization step was disconsidered.

scholarly journals Bond Strengths of Silorane- and Methacrylate-Based Composites to Various Underlying Materials

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sezin Ozer ◽  
Emine Sen Tunc ◽  
Nihan Gonulol
Keyword(s):  
Shear Bond Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
Significance Level ◽  
Low Elastic Modulus ◽  
Resin Modified Glass Ionomer ◽  
Bond Strengths ◽  
Post Hoc ◽  
Ionomer Cement

Objective. To evaluate shear bond strength (SBS) values of a methacrylate (FZ 250) and a silorane-based (FS) resin composite to various underlying materials.Materials and Methods. A total of 80 samples were prepared with four different underlying materials; a flowable (FLC) and a bulk-fill flowable composite (BFC), and a conventional (CGIC) and resin modified glass-ionomer cement (RMGIC). These underlying materials were laminated plus to methacrylate or silorane-based resin composites(n=10). To evaluate the specimens SBS values were evaluated with a universal testing machine (cross-head speed; 1.0 mm/min). Statistical comparisons were carried out using two-way ANOVA and Tukey’s post hoc test with a significance level ofP<0.05.Results. SBS values for FZ250 were significantly higher than for FS for all of the underlying materials tested(P<0.05). SBS values of FZ250 to BFC were significantly higher than to all other materials(P<0.05), whereas SBS values of FS did not vary significantly according to underlying material(P>0.05).Conclusion. The use of FS in conjunction with any of the tested materials showed lower SBS than the FZ 250. Also, new low elastic modulus liner BFC presented slightly good interfacial adhesion so, the usage of BFC as an underlying material may be preferable for FZ 250.

Evaluation of Bond Strength and Microleakage of a Novel Metal-titanate Antibacterial Agent

2016 ◽  
Vol 41 (3) ◽  
pp. E48-E56 ◽  
Author(s):  
S Deng ◽  
KH Chung ◽  
DCN Chan ◽  
C Spiekerman
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Adhesive System ◽  
Class V ◽  
Bonding Agents ◽  
Dental Adhesive ◽  
Universal Testing ◽  
The Mean ◽  
Post Hoc

SUMMARY Objectives: To evaluate the effect on both bond strength and microleakage of incorporation of a novel antibacterial nanoparticulate metal-titanate complex (nMT) into a dental adhesive system. Materials and Methods: Eighty extracted human molars were prepared to determine whether incorporation of nMT into bonding agents can affect shear bond strength (SBS) and adhesive strength fatigue. SBS was measured with a universal testing machine, and the peak force at failure was recorded. An electromechanical fatigue machine was used for cyclic loading treatment of specimens. Differences in the SBS values among groups were identified using analysis of variance and Tukey post hoc analyses (α=0.05). Twenty standard Class V cavities were restored to examine microleakage when the primer/bonding resin was modified with 10 wt% nMT. Microleakage at the enamel and dentin margins was calculated as a percentage of the full length of the cavity. Results of the microleakage experiment were analyzed with paired and independent sample t-tests (α=0.05). Results: The mean (± standard deviation) shear bond strength values of before fatigue and after fatigue ranged from 21.9 (2.5) MPa to 23.9 (3.8) MPa and from 17.1 (2.5) MPa to 17.7 (2.5) MPa respectively. No statistically significant differences in failure force were observed among groups (p=0.70). Microleakage under all conditions was significantly greater in the dentin margins than in the enamel margins (p&lt;0.05). There was no evidence that microleakage differed between the experimental groups with modified primer and bonding resin. Conclusions: Incorporating nMT into a dental adhesive system will not compromise the resin composite's tooth bonding and sealing ability.

scholarly journals Effects of Fluorosis and Self Etching Primers on Shear Bond Strengths of Orthodontic Brackets

2009 ◽  
Vol 03 (03) ◽  
pp. 173-177 ◽  
Author(s):  
Ahmet Yalcin Gungor ◽  
Hakan Turkkahraman ◽  
Necdet Adanir ◽  
Huseyin Alkis
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Orthodontic Brackets ◽  
Universal Testing ◽  
Adhesive Remnant Index ◽  
Halogen Light ◽  
Significant Difference ◽  
Bond Strengths ◽  
Group Ii ◽  
Clinical Changes

ABSTRACTObjectives: To evaluate the effects fluorosis and self etching primers (SEP) on shear bond strengths (SBS) of orthodontic brackets.Methods: A total of 48 (24 fluorosed and 24 non-fluorosed) non-carious freshly extracted human permanent premolar teeth were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. Fluorosed and non-fluorosed teeth were randomly assigned to 4 groups of 12 each. In groups I (non-fluorosed teeth) and II (fluorosed teeth), standard etching protocol was used and brackets were bonded with Light Bond. In groups III (non-fluorosed teeth) and IV (fluorosed teeth), Transbond Plus SEP was used and brackets were bonded with Transbond XT Light Cure Adhesive. All specimens were cured with a halogen light. After bonding, SBS of the brackets were tested with Universal testing machine. After debonding, all teeth and brackets in the test groups were examined under 10x magnifications. Any adhesive remained after debonding was assessed and scored according to the modified Adhesive Remnant Index (ARI).Results: ANOVA indicated a significant difference between groups (P<.001). SBS in group II (Light Bond+Fluorosis) were significantly lower than other groups. ARI scores of the groups were also significantly different (P<.001). There was a greater frequency of ARI scores of 1,2 and 3 in group II (Light Bond+Fluorosis).Conclusions: When standard etching protocol was used enamel fluorosis significantly decreased the bond strength of orthodontic brackets. Satisfactory bond strengths were obtained when SEP was used for bonding brackets to the fluorosed teeth. (Eur J Dent 2009;3:173-177)

Impact of Different Fiber Reinforcement on Flexural Strength, Fracture Toughness and Abrasive Resistance of Provisional Restorative Resin

2021 ◽  
Author(s):  
Dr. Pratik Bhatnagar
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Clinical Performance ◽  
Testing Machine ◽  
Surface Hardness ◽  
Abrasive Resistance ◽  
Significance Level ◽  
Post Hoc ◽  
The Impact

Aim: To assess and compare the impact of reinforcement of PMMA with glass fibre, polyethylene fibre and carbon fibres on flexural strength, fracture toughness and abrasive resistance. Background: In view of inadequate mechanical and physical characteristics of PMMA which include low impact strength and low surface hardness and resulting lowered clinical performance of the prosthesis, the study was designed to investigate the impact of reinforcement of PMMA with glass, polyethylene and carbon fibers on flexural strength, fracture toughness and abrasive resistance. Methods and Findings: Rectangular specimens (n=120; 30 each from 4 groups; 65 × 10 × 3.3 mm3) were fabricated and loaded on Universal Testing Machine until fracture for flexural strength and fracture toughness and on Taber Abrasive Tester for abrasive resistance. Data were analyzed using one–way ANOVA followed by Post Hoc test - Bonferroni multiple comparison analysis, using significance level of 0.05. Significant increase in fracture toughness was observed in specimens reinforced with polyethylene and carbon fiber, albeit the values of flexural strength were increased insignificantly. Specimens reinforced with glass and carbon fiber had significantly low values of abrasive resistance. Conclusion: Findings indicate that reinforcement of PMMA by non-specific fibers like glass, polyethylene and carbon resulted in significant increase in fracture toughness and decrease in abrasive resistance.

The Effect of Thermoforming on Tear Strength of Ethylene Vinyl Acetate Mouthguard Material in Various Thicknesses

2017 ◽  
Vol 751 ◽  
pp. 657-662
Author(s):  
Phakphum Srinuan ◽  
Jeerapatr O. Baiyokvichit ◽  
Rasana Boonpeng ◽  
Tanapol Wongwisatekit ◽  
Pacharaporn Pattanasukwasan ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
Testing Machine ◽  
Ethylene Vinyl Acetate ◽  
Strength Test ◽  
Tear Strength ◽  
Universal Testing ◽  
Significant Difference ◽  
The Mean ◽  
Thermoforming Process ◽  
One Way Anova

The effect of thermoforming on the tear strength of ethylene vinyl acetate (EVA) mouthguard material (Bioplast®) has not been widely investigated. The present study compared the tear strengths of non-processed and processed EVA specimens in various thicknesses. Two groups of EVA sheet (non-processed and processed) in three different thicknesses of 3, 4 and 5 mm were used in specimen fabrication. The processed EVA sheets were achieved by forming the EVA sheet on the cylindrical stone model with the pressure-molding device (Biostar®). Twelve of tear strength specimens of non-processed and processed group in each thickness were prepared following the modified ASTM D 624-00 guideline. The tear strength test was conducted using universal testing machine (Lloyd® 1K series) with the speed of 500 mm/min. The mean thickness and tear strength of the non-processed and processed specimens in each thickness were compared using independent T-test. The differences in the mean tear strength for each thickness of non-processed and process specimens were determined using one-way ANOVA. The mean tear strength and mean thickness of processed EVA specimens was significantly lower than the non-processed EVA specimens for every thickness (P ≤ 0.05). There was no significant difference in the mean tear strength of EVA specimens among each thickness in both non-processed and processed groups. It can be concluded that the thermoforming process has the significant effect on the tear strength of the EVA mouthguard material formed by pressure molding device in every thicknesses. The tear strength of processed specimens were significant lower than the non-processed. Thus, it is more relevant for testing properties of the processed mouthguard material that the mouthguard material before processing.

scholarly journals Influence of Light Intensity on Surface Free Energy and Dentin Bond Strength of Core Build-up Resins

2015 ◽  
Vol 40 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Y Shimizu ◽  
A Tsujimoto ◽  
T Furuichi ◽  
T Suzuki ◽  
K Tsubota ◽  
...  
Keyword(s):  
Free Energy ◽  
Light Intensity ◽  
Bond Strength ◽  
Surface Free Energy ◽  
Testing Machine ◽  
Contact Angles ◽  
Significance Level ◽  
The Core ◽  
Light Intensities ◽  
Bond Strengths

SUMMARY Objective We examined the influence of light intensity on surface free energy characteristics and dentin bond strength of dual-cure direct core build-up resin systems. Methods Two commercially available dual-cure direct core build-up resin systems, Clearfil DC Core Automix with Clearfil Bond SE One and UniFil Core EM with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in acrylic resin and the facial dentin surfaces were wet ground on 600-grit silicon carbide paper. Adhesives were applied to dentin surfaces and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm2. The surface free energy of the adhesives (five samples per group) was determined by measuring the contact angles of three test liquids placed on the cured adhesives. To determine the strength of the dentin bond, the core build-up resin pastes were condensed into the mold on the adhesive-treated dentin surfaces according to the methods described for the surface free energy measurement. The resin pastes were cured with the same light intensities as those used for the adhesives. Ten specimens per group were stored in water maintained at 37°C for 24 hours, after which they were shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. Two-way analysis of variance (ANOVA) and a Tukey-Kramer test were performed, with the significance level set at 0.05. Results The surface free energies of the adhesive-treated dentin surfaces decreased with an increase in the light intensity of the curing unit. Two-way ANOVA revealed that the type of core build-up system and the light intensity significantly influence the bond strength, although there was no significant interaction between the two factors. The highest bond strengths were achieved when the resin pastes were cured with the strongest light intensity for all the core build-up systems. When polymerized with a light intensity of 200 mW/cm2 or less, significantly lower bond strengths were observed. Conclusions The data suggest that the dentin bond strength of core build-up systems are still affected by the light intensity of the curing unit, which is based on the surface free energy of the adhesives. On the basis of the results and limitations of the test conditions used in this study, it appears that a light intensity of &gt;400 mW/cm2 may be required for achieving the optimal dentin bond strength.

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