scholarly journals Effect of thermal and mechanical cycles on shear bond strength of zirconia core to porcelain veneer under different surface treatments

2019 ◽  
Vol 13 (3) ◽  
pp. 227-233
Author(s):  
Tahereh Ghaffari ◽  
Elnaz Moslehifard ◽  
Mehrnaz Motiei

Background. Due to the fragile nature of all-ceramic restorations, it is necessary to provide an appropriate (core) infrastructure to support the veneering porcelain. The veneer detachment and chipping are disadvantages of these restorations. Several techniques have been proposed to minimize these problems. This study evaluated the effect of thermal and mechanical cycles on the shear bond strength of zirconia core to porcelain veneer under different surface treatments. Methods. Sixty disk-like zirconium samples were randomly divided into three groups. The first group was polished and veneered with porcelain, without additional surface treatments. The two other groups were subjected to different surface treatments (modified aluminum oxide by silica and activator‒aluminum oxide and primer) and veneering with porcelain. Half of the samples in each group were subjected to 6000 thermal cycles and 20,000 masticatory cycles of 50 N to imitate the intraoral conditions; the other half were placed in distilled water at 37°C until the shear strength test. Each sample was then buried using PMMA in a mounting jig so that the gap between the core and the veneer could be placed upward. Then, they were exposed to shear stress using a universal testing machine at a rate of 1 mm/min until fracture. The maximum force leading to the fracture was recorded. Results. Comparison of the groups showed that the highest shear bond strength was related to the samples treated with aluminum oxide and primer, without applying thermal and masticatory cycles, which indicated no significant difference from the group treated with aluminum oxide and primer, with thermal and masticatory cycles. The lowest shear bond strengths were related to the polished samples without surface treatment by applying thermal and masticatory cycles (P=0.001), which indicated no significant difference from the untreated group without thermal and masticatory cycles. Conclusion. Based on the results, treatment with aluminum oxide and primer increased the shear bond strength of zirconia core to porcelain veneer. Thermocycling and masticatory cycles failed to reduce the shear bond strength in all the three groups significantly.

2014 ◽  
Vol 15 (6) ◽  
pp. 688-692 ◽  
Author(s):  
Sukumaran Anil ◽  
Farouk Ahmed Hussein ◽  
Mohammed Ibrahim Hashem ◽  
Elna P Chalisserry

ABSTRACT Objective The purpose of the current in-vivo study was to assess the effect of using 0.12% chlorhexidine (CHX) mouth rinse, before bonding, on shear bond strength of polycarbonate brackets bonded with composite adhesive. Subjects and methods Eighteen orthodontic patients with a mean age 21.41 ± 1.2 years, who were scheduled to have 2 or more first premolars extracted, were included in this study. Patients were referred for an oral prophylaxis program which included, in part, the use of a mouth rinse. Patients were divided into 2 groups, a test group of 9 patients who used 0.12% CHX gluconate mouth rinse twice daily and a control group of 9 patients who used a mouth rinse without CHX, but with same color. After 1 week, polycarbonate brackets were bonded to first premolars with Transbond XT composite adhesive. Premolars were extracted after 28 days and tested for shear bond strength on a universal testing machine. Student's t-test was used to compare shear bond strengths of both groups. Results No statistically significant difference was found in bond strengths’ values between both groups. The test group (with CHX) has mean shear bond strength of 14.21 ± 2.42 MPa whereas the control group (without CHX) revealed a mean strength of 14.52 ± 2.31 MPa. Conclusion The use of 0.12% CHX mouth rinse, for one week before bonding, did not affect the shear bond strength of polycarbonate brackets bonded with Transbond composite. Furthermore, these brackets showed clinically acceptable bond strength. How to cite this article Hussein FA, Hashem MI, Chalisserry EP, Anil S. The Impact of Chlorhexidine Mouth Rinse on the Bond Strength of Polycarbonate Orthodontic Brackets. J Contemp Dent Pract 2014;15(6):688-692.


2016 ◽  
Vol 17 (11) ◽  
pp. 920-925 ◽  
Author(s):  
Bandar MA Al-Makramani ◽  
Fuad A Al-Sanabani ◽  
Abdul AA Razak ◽  
Mohamed I Abu-Hassan ◽  
Ibrahim Z AL-Shami ◽  
...  

ABSTRACT Aim The aim of this study was to evaluate the effect of surface treatments on shear bond strength (SBS) of Turkom-Cera (Turkom-Ceramic (M) Sdn. Bhd., Puchong, Malaysia) all-ceramic material cemented with resin cement Panavia-F (Kuraray Medical Inc., Okayama, Japan). Materials and methods Forty Turkom-Cera ceramic disks (10 mm × 3 mm) were prepared and randomly divided into four groups. The disks were wet ground to 1000-grit and subjected to four surface treatments: (1) No treatment (Control), (2) sandblasting, (3) silane application, and (4) sandblasting + silane. The four groups of 10 specimens each were bonded with Panavia-F resin cement according to manufacturer's recommendations. The SBS was determined using the universal testing machine (Instron) at 0.5 mm/min crosshead speed. Failure modes were recorded and a qualitative micromorphologic examination of different surface treatments was performed. The data were analyzed using the one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests. Results The SBS of the control, sandblasting, silane, and sandblasting + silane groups were: 10.8 ± 1.5, 16.4 ± 3.4, 16.2 ± 2.5, and 19.1 ± 2.4 MPa respectively. According to the Tukey HSD test, only the mean SBS of the control group was significantly different from the other three groups. There was no significant difference between sandblasting, silane, and sandblasting + silane groups. Conclusion In this study, the three surface treatments used improved the bond strength of resin cement to Turkom-Cera disks. Clinical significance The surface treatments used in this study appeared to be suitable methods for the cementation of glass infiltrated all-ceramic restorations. How to cite this article Razak AAA, Abu-Hassan MI, AL-Makramani BMA, AL-Sanabani FA, AL-Shami IZ, Almansour HM. Effect of Surface Treatments on the Bond Strength to Turkom-Cera All-Ceramic Material. J Contemp Dent Pract 2016;17(11):920-925.


2018 ◽  
Vol 6 (3) ◽  
pp. 548-553 ◽  
Author(s):  
Bandar M. A. Al–Makramani ◽  
Abdul A. A. Razak ◽  
Mohamed I. Abu–Hassan ◽  
Fuad A. Al–Sanabani ◽  
Fahad M. Albakri

BACKGROUND: The selection of the appropriate luting cement is a key factor for achieving a strong bond between prepared teeth and dental restorations.AIM: To evaluate the shear bond strength of Zinc phosphate cement Elite, glass ionomer cement Fuji I, resin-modified glass ionomer cement Fuji Plus and resin luting cement Panavia-F to Turkom-Cera all-ceramic material.MATERIALS AND METHODS: Turkom-Cera was used to form discs 10mm in diameter and 3 mm in thickness (n = 40). The ceramic discs were wet ground, air - particle abraded with 50 - μm aluminium oxide particles and randomly divided into four groups (n = 10). The luting cement was bonded to Turkom-Cera discs as per manufacturer instructions. The shear bond strengths were determined using the universal testing machine at a crosshead speed of 0.5 mm/min. The data were analysed using the tests One Way ANOVA, the nonparametric Kruskal - Wallis test and Mann - Whitney Post hoc test.RESULTS: The shear bond strength of the Elite, Fuji I, Fuji Plus and Panavia F groups were: 0.92 ± 0.42, 2.04 ± 0.78, 4.37 ± 1.18, and 16.42 ± 3.38 MPa, respectively. There was the statistically significant difference between the four luting cement tested (p < 0.05).CONCLUSION: the phosphate-containing resin cement Panavia-F exhibited shear bond strength value significantly higher than all materials tested.


2016 ◽  
Vol 18 (2) ◽  
pp. 109
Author(s):  
M.T. Muñoz MSc ◽  
E. Reales DDS ◽  
L.H.M. Prates DDS, MSc, PhD ◽  
C.A.M. Volpato DDS, MSc, PhD

The aim of this study was to compare the shear bond strength between acrylic resin teeth and autopolymerizing acrylic resin repairs after different surface treatments. Seventy-two upper anterior acrylic resin denture teeth (MFT, Vita, Germany) were selected. Specimens were randomly assigned into six groups (n=12): G1-C, without surface treatment (control); G2-M, methylmetacrylate monomer (Jet, Clássico, Brazil) application; G3-A treatment with methylmetacrylate and metiletilcetone-based bonding agent (Vitacoll, Vita, Germany). The surface of G4-OA, G5-OAM and G6-OAA was airborne-particle abraded with aluminum oxide (Polidental, Wilson, Brazil); being repeated the treatments respectively of groups G1-C, G2-M e G3-A. All groups were then repaired with autopolymerizing acrylic resin (Jet, Clássico, Brazil). Shear bond strength test was performed using an universal testing machine (Instron 4444). Two-way ANOVA and post hoc Tukey’s analysis (p<0,05) were used for statistical comparison. The shear bond strengths of groups G4-OA, G5-OAM and G6-OAA were significantly higher (p<0,05) than that of groups G1-C, G2-M and G3-A. The shear bond strength of Group G3-A were significantly higher (p<0,05) than that of groups G1-C and G2-M. In conclution, chemical treatments in combination with bondig agents showed significant improvements in bond strength without aluminum oxide treatment. More significantly, surface treatment with aluminum oxide particles resulted in the highest bond strength values for acrylic resin teeth repaired with autopolymerizing acrylic resin. 


2005 ◽  
Vol 16 (3) ◽  
pp. 202-206 ◽  
Author(s):  
Ricardo Alves do Prado ◽  
Heitor Panzeri ◽  
Alfredo Julio Fernandes Neto ◽  
Flávio Domingues das Neves ◽  
Marlete Ribeiro da Silva ◽  
...  

The continuous technological advance and increasing availability of new base metal alloys and ceramic systems in the market, coupled to the demands of daily clinical practice, have made the constant evaluation of the bond strength of metal/porcelain combinations necessary. This study evaluated the metal/porcelain shear bond strength of three ceramic systems (Duceram, Williams and Noritake) in combination with three nickel-chromium (Ni-Cr) alloys (Durabond, Verabond and Viron). Thirty cast cylinder specimens (15 mm high; 6 mm in diameter) were obtained for each alloy, in a way that 10 specimens of each alloy were tested with each porcelain. Bond strength was measured with an Emic screw-driven mechanical testing machine by applying parallel shear forces to the specimens until fracture. Shear strength was calculated using the ratio of the force applied to a demarcated area of the opaque layer. Mann-Whitney U test was used for statistical analysis of the alloy/ceramic combinations (p<0.05). Viron/Noritake had the highest shear bond sregnth means (32.93 MPa), while Verabond/Duceram (16.31 MPa) presented the lowest means. Viron/Noritake differed statistically from other combinations (p<0.05). Viron/Duceram had statistically significant higher bond strengths than Verabond/Duceram, Verabond/Williams and Durabond/Noritake (p<0.05). It was also found significant difference (p<0.05) between Verabond/Noritake, Verabond/Duceram and Durabond/Noritake. No statistically significant difference (p>0.05) were observed among the other combinations. In conclusion, the Noritake ceramic system used together with Viron alloy presented the highest resistance to shear forces, while Duceram bonded to Verabond presented the lowest bond strength. Viron/Duceram and Verabond/Noritake provided intermediate results. The combinations between the Williams ceramic system and Ni-Cr alloys had similar shear strengths among each other.


2007 ◽  
Vol 77 (6) ◽  
pp. 1096-1100 ◽  
Author(s):  
Hakan Türkkahraman ◽  
Necdet Adanir

Abstract Objective: To evaluate the effects of potassium nitrate and oxalate desensitizer agents on shear bond strengths of orthodontic brackets. Materials and Methods: Forty-five extracted human premolar teeth were randomly assigned to three groups of 15 each. UltraEZ potassium nitrate desensitizer was applied on teeth in the first group, while BisBlock oxalate desensitizer was applied on teeth in the second group. The third group served as a control. Orthodontic brackets were bonded with a light cure composite resin and cured with a halogen light. After bonding, the shear bond strength of the brackets was tested with a universal testing machine. Results: The highest shear bond strengths were measured in Group III. The shear bond strength in Groups I and II was significantly lower than in Group III (P &lt; .001). Significant difference was also found between Group I and Group II (P &lt; .01). Conclusions: Orthodontic brackets bonded to enamel treated with potassium nitrate and oxalate desensitizers showed significantly lower bond strengths than did brackets bonded to untreated enamel.


2019 ◽  
Vol 9 (1) ◽  
pp. 11-14
Author(s):  
Vivek Bikram Thapa ◽  
Amrita Shrestha ◽  
Prabesh Sherchan ◽  
Prakash Poudel ◽  
Luna Joshi

 Introduction: Direct and indirect bonding has revolutionized clinical orthodontics by reducing chair-side time and enhancing patient comfort. Clinicians often hesitate to bond molars due to ambiguity on shear bond strength. This study was conducted to compare shear bond strengths of two commercially available bondable molar tubes. And asses mesh if the mesh design had a role to play in differences in shear bond strength. Materials & Method: 30 extracted maxillary molars were divided into Group I and II (n=15).Group I bonded with Victory series MBT (3M Unitek). And Group II bonded with Ortho classic proprietary Pad- Lok (Navy orthodontics). Teeth were mounted on a jig and Shear Bond Strength was evaluated on an Instron universal testing machine at a cross head speed of 1mm/minute. They were also subjected to scanning microscopic examination to check the base pattern. Result: Shear bond strength of navy orthodontic tubes were (18.0675+/- 4.0187 MPa) was significantly higher than 3M victory series (8.93 +/2.493MPa). Unpaired T-test shows a higher significant difference in SBS between two groups at 1% of significance. SME showed that navy orthodontic tube base was pad-lock mesh design, while 3M was a single mesh base design. Conclusion: 3M victory series molar tube exhibited a near ideal while other sample showed far higher shear bond strength than recommended. Higher values may result in enamel fracture.


2014 ◽  
Vol 39 (6) ◽  
pp. E250-E260 ◽  
Author(s):  
TA Imbery ◽  
T Gray ◽  
F DeLatour ◽  
C Boxx ◽  
AM Best ◽  
...  

SUMMARY Objective Repairing composite restorations may be a more conservative treatment than replacing the entire restoration. The objective of this in vitro study was to determine the best repair method by measuring flexural, diametral tensile, and shear bond strength of repaired composites in which the surfaces were treated with chemical primers (Add & Bond or Silane Bond Enhancer), a bonding agent (Optibond Solo Plus [OBSP]), or mechanical retention with a bonding agent. Methods Filtek Supreme Ultra shade B1B was placed in special molds to fabricate specimens that served to test the flexural, diametral tensile, or shear strength of the inherent resin substrate. The same molds were modified to make specimens for testing repair strength of the resin. Repairs were made immediately or after aging in deionized water at 37°C for seven days. All repair sites were finished with coarse Sof-Lex discs to simulate finishing new restorations or partially removing aged restorations. Repair surfaces were treated with one of the following: 1) phosphoric-acid etching and OBSP; 2) Add & Bond; 3) phosphoric-acid etching, Silane Bond Enhancer, and OBSP; or 4) quarter round bur, phosphoric-acid etching, and OBSP. Specimens were placed back in the original molds to fabricate specimens for diametral tensile or flexural testing or in an Ultradent jig to make specimens for shear bond testing. Composite resin in shade B5B was polymerized against the treated surfaces to make repairs. Two negative control groups for the three testing methods consisted of specimens in which repairs were made immediately or after aging without any surface treatments. Controls and experimental repairs were aged (water 37°C, 24 hours) before flexural, diametral tensile, or shear testing in an Instron Universal testing machine at a crosshead speed of 0.5 mm/min. Results Experimental flexural repair strengths ranged from 26.4% to 88.6% of the inherent substrate strength. Diametral tensile repair strengths ranged from 40% to 80% of the inherent substrate strength, and shear bond strength repairs ranged from 56% to 102%. Geometric means were statistically analyzed with two-way analysis of variance on their log-transformed values. Significant differences were determined using Tukey honestly significant difference (p&lt;0.05). Conclusions Depending on the mechanical property being tested, surface treatments produced different results. OBSP produced more consistent results than chemical primers.


2021 ◽  
Vol 10 (13) ◽  
pp. e34101320132
Author(s):  
Luciana de Vasconcelos Leão ◽  
Adriana Oliveira ◽  
Jefferson Chaves Moreira ◽  
Luiz Renato Paranhos ◽  
Sigmar de Mello Rode ◽  
...  

This research aimed to assess the effect of aluminum oxide sandblasting and discs on the bond strength of metal brackets rebonded on artificially eroded enamel. Fifty-four bovine incisors were divided into groups: Control (Artificial Saliva), AlOx (Aluminum oxide sandblasting), and SL (Aluminum oxide discs). They had their enamel surface flattened with Al2O3 discs and a metallographic polisher, then Knoop microhardness was assessed. AlOx and SL specimens were eroded with Coca-Cola™ for 1 minute, 3 times a day for 7 days. Metal brackets were bonded to the tooth. Shear strength was measured by an EMIC universal testing machine (0.5 mm/min). The Adhesive Remnant Index (ARI) was performed after shearing through magnifying glass (10X). Kolmogorov-Smirnov, Levene, homoscedasticity and ANOVA tests were applied to assess microhardness and shear strength (p=0.163). All groups presented shear bond strength with no significant differences. The ARI showed statistically significant difference between the groups. The prevalence for the control group was ARI 3. However for AlOx and SL, ARI 1 and 2 prevailed. The aluminum oxide sandblasting and aluminum oxide discs did not positively increase the bond strength of brackets when bonded to artificially eroded enamel. The ARI indicated that eroded teeth present higher resin adhesion to enamel.


2016 ◽  
Vol 18 (2) ◽  
pp. 109
Author(s):  
M.T. Muñoz MSc ◽  
E. Reales DDS ◽  
L.H.M. Prates DDS, MSc, PhD ◽  
C.A.M. Volpato DDS, MSc, PhD

The aim of this study was to compare the shear bond strength between acrylic resin teeth and autopolymerizing acrylic resin repairs after different surface treatments. Seventy-two upper anterior acrylic resin denture teeth (MFT, Vita, Germany) were selected. Specimens were randomly assigned into six groups (n=12): G1-C, without surface treatment (control); G2-M, methylmetacrylate monomer (Jet, Clássico, Brazil) application; G3-A treatment with methylmetacrylate and metiletilcetone-based bonding agent (Vitacoll, Vita, Germany). The surface of G4-OA, G5-OAM and G6-OAA was airborne-particle abraded with aluminum oxide (Polidental, Wilson, Brazil); being repeated the treatments respectively of groups G1-C, G2-M e G3-A. All groups were then repaired with autopolymerizing acrylic resin (Jet, Clássico, Brazil). Shear bond strength test was performed using an universal testing machine (Instron 4444). Two-way ANOVA and post hoc Tukey’s analysis (p<0,05) were used for statistical comparison. The shear bond strengths of groups G4-OA, G5-OAM and G6-OAA were significantly higher (p<0,05) than that of groups G1-C, G2-M and G3-A. The shear bond strength of Group G3-A were significantly higher (p<0,05) than that of groups G1-C and G2-M. In conclution, chemical treatments in combination with bondig agents showed significant improvements in bond strength without aluminum oxide treatment. More significantly, surface treatment with aluminum oxide particles resulted in the highest bond strength values for acrylic resin teeth repaired with autopolymerizing acrylic resin. 


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