Reliability and correlation between microshear and microtensile bond strength tests of composite repairs

Author(s):  
Isabelle Adad Fornazari ◽  
Rafael Torres Brum ◽  
Rodrigo Nunes Rached ◽  
Evelise Machado de Souza
2017 ◽  
Vol 20 (4) ◽  
pp. 55
Author(s):  
Rafael Avellar de Carvalho Nunes ◽  
Flávia Lucisano Botelho do Amaral ◽  
Fabiana Mantovani Gomes França ◽  
Cecilia Pedroso Turssi ◽  
Roberta Tarkany Basting

<p class="Corpo"><strong>Objective</strong>: the aim of the present study was to evaluate the influence of adding different concentrations of chitosan to an experimental two-step etch-and-rinse adhesive system on the bond strength and failure mode to dentin. <strong>Material</strong> <strong>and</strong> <strong>Methods</strong>: thirty-two flat dentin surfaces were obtained from extracted human third molars and divided into four groups  (n=8) for application of the adhesive systems: AD - conventional two-step adhesive system (Adper Single Bond 2); EXP – experimental two-step etch-and-rinse adhesive system; Chi0.2% - EXP with addition of 0.2% Chitosan; Chi0.5% - EXP with addition of 0.5% Chitosan. Resin composite build-ups were made and the composite/dentin specimens were sectioned to obtain rectangular beams with a bond area of approximately 1mm<sup>2</sup>. After 24 hours, the sticks were submitted to microtensile bond strength tests in a universal test machine. The fracture pattern was evaluated under a stereoscopic loupe at 40X magnification. <strong>Results</strong>: one-way analysis of variance showed that the type of adhesive system had no significant effect on the bond strength values (p = 0.142), showing the mean bond strength values (standard deviation), in MPa, for the groups as follows: AD=20.1 (5.4); EXP=16.6 (2.3); Chi0.2%=16.1 (2.8); Chi0.5%=16.9 (2.3). In all the groups there was predominance of cohesive fractures in dentin, representing 68 to 82% of the failure modes. <strong>Conclusion</strong>: the addition of 0.2 or 0.5% of chitosan had no influence on the bond strength and failure mode of an experimental two-step etch-and-rinse adhesive system to dentin.</p><p class="Corpo"><strong>Keywords</strong></p><p class="Corpo">Chitosan; Dental Adhesives; Failure Mode; Microtensile Bond Strength.</p>


2021 ◽  
Vol 10 (8) ◽  
pp. e46310817518
Author(s):  
Heitor Ceolin Araujo ◽  
Andressa Restani ◽  
Eliane Cristina Gava Pizi ◽  
Anderson Catelan ◽  
Rosana Leal do Prado ◽  
...  

Repair in resin-based composite is a procedure that has shown good results, when properly indicated. In cases of fracture or stainning, the total removal of the restoration can cause unnecessary wear on the dental element. This study evaluated the aging effect on the bond strength of a universal adhesive containing silane, and/or application of silane separately for composite repairs. Resin composite blocks were thermocycled and divided according to adhesion protocol (n=10): silane(Sil), conventional adhesive(CA), universal adhesive(UA), Sil+CA(SilCA), and Sil+UA(SilUA). Layers of resin composite were added and blocks were sectioned and divided into 2 subgroups: 24h and 4 months of water storage. Microtensile bond strength test was performed and data were statistically analyzed (a = 0.05).  After 4months of aging SilCA and SilUA showed a significant bond strength reduction, while for UA the bonding remained stable.


2010 ◽  
Vol 18 (6) ◽  
pp. 591-598 ◽  
Author(s):  
Andrea Mello de Andrade ◽  
Sandra Kiss Moura ◽  
Alessandra Reis ◽  
Alessandro Dourado Loguercio ◽  
Eugenio Jose Garcia ◽  
...  

2021 ◽  
pp. 232020682199798
Author(s):  
Beyza Unalan Degirmenci ◽  
Alperen Degirmenci ◽  
Emine Kara

Aim: Natural antioxidants were offered as the answer of dentin adhesion issue. The aim of this study is to investigate the effects of proanthocyanidin and lycopene as pretreatment agents on the sound and caries-affected dentin surface on microtensile bond strength and microleakage. Materials and Methods: This study was designed as in vitro because of that 84 mandibular molar teeth were collected. Forty-two of the included teeth were carious teeth, while the other 42 were without caries. Sixty of them were used for microleakage and 24 for microtensile bond strength testing and scanning electron microscopy analysis. The samples were divided into six subgroups randomly according to dentin pretreatments: 5% proanthocyanidin, 5% lycopene, and no antioxidant application. After the restorative procedures, samples were attached to the microtensile tester. Samples were subjected to tensile stress in the load cell until they broke at a speed of 0.5 mm per min. Microtensile bond strength (µTBS) and microleakage test data were analyzed with two-way analysis of variance, Bonferroni correction, and Tamhane’s T2 tests. Results: Two-way variance analysis showed that dentin pretreatment applications, dentin substrate, and the interaction between these two parameters had statistically significant effects on µTBS values ( P < .001). There was no difference between dentin pretreatment applications in terms of microleakage scores ( P > .05). Conclusion: The application of dentin pretreatment with proanthocyanidin is a successful procedure that increases the bond strength in both dentin substrate, while pretreatment with lycopene in caries-affected dentin reduces it.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 450
Author(s):  
Apinya Limvisitsakul ◽  
Suppason Thitthaweerat ◽  
Pisol Senawongse

This paper presents the effect of blade type and feeding force during resin-bonded dentin specimen preparation on the microtensile bond strength (μTBS) test. Forty resin-bonded flat middle dentin specimens were divided into four groups. The specimens of each group were sectioned according to type of blade and feeding force as follows: fine grit/20 N, fine grit/40 N, medium grit/20 N, and medium grit/40 N to obtain resin-dentin sticks with a cross-sectional area of 1.0 mm2. Four sticks from the center of each tooth were subjected to the μTBS test. Five remaining sticks of each group were selected for surface topography observation under a scanning electron microscope (SEM). As a result, the bond strength of the medium-grit group was higher than that of the fine-grit group (p < 0.001), whereas the feeding force had no influence on bond strength values (p = 0.648). From the SEM, sticks prepared with the fine-grit blade showed a smoother surface integrity and fewer defects on the specimen edges in comparison with the sticks prepared with the medium-grit blade. The grit type of the blade is one of the considerable factors that may affect the bond strength and the surface integrity of resin-dentin specimens for microtensile testing.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4174
Author(s):  
André M. Santos ◽  
Ângelo J. Costa e Silva ◽  
João M. F. Mota ◽  
João M. P. Q. Delgado ◽  
Fernando A. N. Silva ◽  
...  

The understanding of the mechanical fixation behavior of coatings is crucial for a better comprehension of the bonding systems, especially at the interface between the mortar and the substrate. Physical adherence is related, among other things, to the contents of the materials used in the roughcast and mortar coatings, due to the colloidal water penetration into the pores of the substrate. This work evaluated the influence of different lime solution additions replacing the kneading water in the preparation of roughcast and mortar coatings. Two types of substrates were investigated:ceramic bricks and concrete blocks. Three wall masonry panels were constructed, with dimensions of 220 × 180 cm2, one of concrete block and two of ceramic bricks, followed by the application of roughcast and mortar coating with an average thickness of 5 mm and 20 mm, respectively. Direct tensile bond strength tests were performed and the results, with a 95% confidence level, showed that substrate ceramic and treatment in the roughcast exhibited a better behavior regarding the distribution of the tensile bond strength of the tested specimens. However, no significant differences of the amount of addition used (0%, 5%, 10% and 15%) on the tensile bond strength were observed.


2018 ◽  
Vol 2 (3) ◽  
pp. 157-162 ◽  
Author(s):  
Daphne Camara Barcellos ◽  
Priscila Holleben ◽  
Beatriz Maria Fonseca ◽  
Bruna de Cássia Sabino ◽  
Sérgio Eduardo de Paiva Gonçalves

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