scholarly journals Effect of Two Microshear Test Devices on Bond Strength and Fracture Pattern in Primary Teeth

2013 ◽  
Vol 24 (6) ◽  
pp. 605-609 ◽  
Author(s):  
Tamara Kerber Tedesco ◽  
Eugenio Jose Garcia ◽  
Fabio Zovico Maxnuck Soares ◽  
Rachel de Oliveira Rocha ◽  
Rosa Helena Miranda Grande

This in vitro study evaluated the influence of two devices for application of shear load in microshear tests on bond strength and fracture pattern of primary enamel and dentin. Eighty primary molars were selected and flat enamel (40 teeth sectioned mesio-distally) and dentin (40 teeth sectioned transversally) surfaces were obtained. Both surfaces were polished to standardize the smear layer. Two-step etch-and-rinse adhesive systems (Adper Single Bond and XP Bond) were used. Polyethylene tubes was placed over the bonded surfaces and filled with composite resin. The microshear testing was performed after storage in water (24 h/37 °C) using two devices for application of microshear loads: a notched rod (Bisco Shear Bond Tester) or a knife edge (Kratos Industrial Equipment). Failure modes were evaluated using a stereomicroscope. Bond strength data were subjected to ANOVA and chi-square test to compare the failure mode distributions (α=0.05). No significant differences were observed between the groups for dentin and enamel bond strength or fracture patterns (p>0.05). The predominant failure mode was adhesive/mixed. In conclusion, the devices for application of shear loads did not influence the bond strength values, regardless of adhesive system and substrate.

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 ◽  
pp. 232020682199798
Author(s):  
Sema Yazici Akbiyik ◽  
Elif Pınar Bakir ◽  
S¸eyhmus Bakir

Aim: To evaluate the bond strengths of pulp capping materials (Dycal, ProRoot MTA, Biodentine, TheraCal LC, Calcimol LC, and ApaCal ART) and different adhesive systems (Gluma 2 Bond, Clearfil SE Protect, Gluma Self Etch, Clearfil S 3 Bond Plus, Gluma Bond Universal, Clearfil S 3 Bond Universal). Materials and Methods: Two hundred fifty-two acrylic blocks were prepared in which cylindrical cavities of 4 × 2 mm 3 were formed. Pulp capping materials were placed in the cavities. Different adhesive systems were applied to each pulp capping material group. After applying the composite resin, the shear bond strength (SBS) values of the specimens were determined in the Instron test device. Fracture types were evaluated using a stereomicroscope and a scanning electron microscope. Data were analyzed by Shapiro–Wilk’s and Kruskal–Wallis H test. Results: There is a statistically significant difference between pulp capping materials in terms of SBS values ( P < .05). Dycal’s SBS was found significantly lower than other materials, and the highest bond strength was observed in Calcimol LC material. Although there is no statistically significant difference ( P > .05) between the adhesive agent groups in terms of SBS, Gluma 2 Bond showed the highest bond strength value. Conclusion: In traditional pulp capping materials such as Dycal, MTA, and Biodentine, using a two-step self-etch adhesive system can result in higher bond strength values. In resin-based TheraCal LC,, ApaCal ART, and Calcimol LC materials, it may be recommended to use a two-step etch and rinse adhesive system.


2021 ◽  
Vol 20 ◽  
pp. e210328
Author(s):  
Ricky Rolim de Moura ◽  
Fabiana Mantovani Gomes França ◽  
Cecilia Pedroso Turssi ◽  
Roberta Tarkany Basting ◽  
Flavia Lucisano Botelho do Amaral

Aim: The in vitro study evaluated the effect of different concentrations of green tea extract solution (GT) on the bonding durability of etch-and-rinse adhesive system to caries dentin affected (CAD). Methods: Dentinal surfaces of human third molars were polished and submitted to a microbiological caries induction protocol for 14 days. After removal of the infected dentin layer, the samples were randomly divided into 4 groups (n= 10), according to the concentration of GT solution applied in CAD, after acid etching: 0.05%; 0.2%; 2% and NT (no treatment – control). After application of a etch-and-rinse adhesive system (Adper Single Bond 2, 3M ESPE), composite resin restorations were performed on the dentin. After 24 hours, the resin-dentin blocks were sectioned 1mm2 specimens, which were subjected to the microtensile test immediately or after 6 months of storage in water. Data were submitted to two-way ANOVA for randomized blocks and Tukey test (α= 5%). Results: There was no effect of double interaction (p= 0.934). The application of 0.2% GT promoted a statistically significant increase in dentin bond strength values in comparison to the condition where GT was not used (p=0.012). There was a significant decrease of bond strength after 6 months of storage, regardless of dentin pretreatment (p = 0.007). The G test identified that there was no statistical difference regarding failure mode (p= 0.326). Conclusion: The concentration of 0.2% improved the bond strength of an etch-and-rinse adhesive system to caries affected dentin, however, none of dentin pretreatments could prevent the decrease in bond strength over time.


2019 ◽  
Vol 18 ◽  
pp. e191638
Author(s):  
Renally Bezerra Wanderley Lima ◽  
Maria Luiza Pontual ◽  
Venâncio Fernandes Dantas ◽  
Sônia Saeger Meireles ◽  
Ana Karina Maciel Andrade ◽  
...  

Aim: The aim of this study is to evaluate the effect of radiotherapy on the bond strength of resin-based composite restorations to dentin, performed either 24 h or 1 year before or after radiation. Methods: Ninety-six posterior teeth were randomly distributed into the following groups: IB (n = 16), irradiated teeth were restored 1 year after x-ray application; NB (n = 16), not irradiated teeth were stored for 1 year and then restored. IA (n = 32), teeth were restored and irradiated at 24 h or 1 year after the restoration. NA (n = 32), teeth were restored, not irradiated, and tested as IA. Eight samples from each group were randomly assigned to either the three-step or two-step etch-and rinse adhesive system procedure. The irradiated specimens were subjected to 60 Gy of x-ray radiation fractionally. The restored teeth were vertically sectioned, and 1-mm2 resin–dentin sticks were obtained and submitted to the microtensile bond strength test. The bond strength data were analyzed by two-way analysis of variance (ANOVA) followed by Tukey’s test (p < 0.05). Failure modes were examined by optical microscopy and scanning electron microscopy. Results: The IB group showed lower bond strength values compared to the NB group. The bond strength values between the adhesive systems were not statistically different. Conclusion: The application of radiation dose decreased the bond strength of the adhesive restorations to dentin when the bonding procedure was conducted 1 year after in vitro radiotherapy.


2020 ◽  
Vol 32 (4) ◽  
pp. 5-11
Author(s):  
Ahmed D Hatf ◽  
Mustafa M AL-Khatieeb

Background: The aim of this study was to evaluate the shear bond strength (SBS) and adhesive remnant index (ARI) of different orthodontic adhesive systems after exposure to aging media (water storage and acid challenge). Materials and methods: Eighty human upper premolar teeth were extracted for orthodontic purposes and randomly divided into two groups (40 teeth each): the first group in which the bonded teeth were stored in distilled water for 30 days at 37°C, and the second group in which the bonded teeth were subjected to acid challenge. Each group was further subdivided into four subgroups (10 teeth each) according to the type of adhesive system that would be bonded to metal brackets: either non-fluoride releasing adhesive (NFRA), fluoride releasing adhesive (FRA), Fluoride releasing bond with self-etching primer (FRBSP), or powder and liquid orthodontic fluoride releasing adhesive (PLFRA). After 30 days of water storage and acid challenge ageing procedures, the SBS was determined using Instron testing machine with a crosshead speed of 1 mm/min. The ARI was assessed using a stereomicroscope with 10 X magnification. Result: The SBS testing revealed significant differences (p< 0.05) among the four tested adhesive systems in water storage and acid challenge groups using ANOVA F-test. In both groups, the NFRA subgroup exhibited the highest mean SBS value, followed by FRASP, then FRA subgroups, while the PLFRA subgroup had the lowest value of mean SBS. The independent t-test showed non-significant differences in mean SBS values between water storage and acid challenge groups. In respect to the ARI analysis, the Chi-square test showed significant differences among the tested adhesive systems. Conclusion: The shear bond strength of the fluoride releasing adhesive system was less than that of the non-fluoride releasing adhesive system, but still above the clinically acceptable range.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mehdi Dastorani ◽  
Behnam Malekpour ◽  
Mohsen AminSobhani ◽  
Mohammadsadegh Alemrajabi ◽  
Arezoo Mahdian ◽  
...  

Abstract Background Bacterial microleakage is an important cause of apical periodontitis and endodontic treatment failure. This study aimed to assess the bacterial microleakage of nano-mineral trioxide aggregate (nano-MTA) as a sealer, Endoseal MTA, and GuttaFlow Bioseal sealers in atmospheric pressure, and simulated underwater diving and aviation conditions. Methods In this in vitro, experimental study, 180 extracted single-rooted teeth were cleaned and shaped, and were then randomly divided into three groups for single-cone obturation using Endoseal MTA, GuttaFlow Bioseal, or nano-MTA as a sealer. Each group was then randomly divided into three subgroups, and subjected to ambient atmospheric pressure, 2 atm pressure (to simulate underwater diving), and 0.5 atm pressure (to simulate aviation) using a custom-made pressure chamber. The teeth then underwent microbial leakage test using Streptococcus mutans (S. mutans), and the percentage of samples showing microleakage was recorded for up to 1 month, and analyzed using the Chi-square test. Results The three sealer groups were significantly different regarding bacterial microleakage (P < 0.05). The nano-MTA group showed significantly higher microleakage after 15 days than the other two groups (P = 0.006). The effect of pressure on bacterial microleakage was not significant in any sealer group (P > 0.05). Conclusion Within the limitations of this in vitro study, it may be concluded that single-cone obturation technique using nano-MTA as a sealer results in lower resistance to bacterial microleakage compared with the use of GuttaFlow Bioseal, and Endoseal MTA. Pressure changes in simulated underwater diving and aviation conditions had no significant effect on bacterial microleakage. Trial Registration Number This is not a human subject research.


2012 ◽  
Vol 17 (4) ◽  
pp. 1-7 ◽  
Author(s):  
Roberto Hideo Shimizu ◽  
Karlos Giovani Grando ◽  
Isabela Almeida Shimizu ◽  
Augusto Ricardo Andriguetto ◽  
Ana Cláudia Moreira Melo ◽  
...  

OBJECTIVE: This in vitro study was designed to evaluate the shear bond strength (SBS) of orthodontic metal brackets bonded by direct and indirect techniques. METHODS: Thirty healthy human maxillary premolar teeth were used. The teeth were divided into three groups of 10 teeth each: Group I - indirect bonding with SondhiTM Rapid-Set system (3M/Unitek), Group II - indirect bonding with TransbondTM XT adhesive system (3M/Unitek) and Group III - direct bonding with TransbondTM XT adhesive system (3M/Unitek). After bonding and obtaining the specimens for the study, the specimens were subjected to SBS testing in a universal testing machine (Emic, model DL-500). The Kolmogorov-Smirnov test was applied to ascertain that the data had a normal distribution and the Bartlett test to check whether there was homogeneity of variance. One-factor analysis of variance was performed and, subsequently, Tukey's test for paired means. A 5% significance level was adopted. RESULTS: The results of Group I were 67.6 (N) and 5.9 (MPa); Group II, 68.9 (N) and 6.1 (MPa) and Group III (control), 92.5 (N) and 8.1 (MPa). CONCLUSION: It can therefore be concluded that the means for Group III were significantly higher compared with Groups I and II in both Newton (N) and Megapascal (MPa) values. The means attained by the indirect bonding technique used in Groups I and II, however, exhibited no statistically significant differences.


2019 ◽  
Vol 3 (9) ◽  
pp. 283-289
Author(s):  
Shuchi Sukul ◽  
Goldy Rathee ◽  
Parimal Anand ◽  
Sakshi Kataria ◽  
Pratibha Taneja

OBJECTIVES: The present research was conducted to assess incidences of root microcracks caused by hand and rotary file system at different lengths MATERIAL AND METHODS: This in-vitro study was undertaken to assess incidence of root microcracks caused by hand and rotary file system at different lengths In total, 100 the mandibular premolar with straight roots determined with intact, fully formed apices were taken. Samples were randomly distributed into 5 groups based on the file system used: a) Group A: Control, b) Group B: Reciproc, c) Group C: WaveOne, d) Group D: One Shape and e) Group E: ProTaper. Pearson Chi-square test was used to determine the differences between groups. The dentinal defects were expressed as percentage of samples with microcracks in each group. Level of statistical significance was set at p-value less than 0.05. RESULTS: The chi square test was used to compare the Distribution of the number of teeth in which cracks were observed on the horizontal sections. It was found to be significant with group ProTaper showing maximum cracks at 3,6,9 mm level as compared to other file systemCONCLUSION: Nickel-titanium instruments causes cracks on the apical root surface or in the root canal wall. ProTaper causes maximum dentinal cracks as compared to other file systems


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Sabra Jaâfoura ◽  
Amira Kikly ◽  
Saida Sahtout ◽  
Mounir Trabelsi ◽  
Dorra Kammoun

Introduction. This in vitro study compared the shear strength of three composite resin systems to fluorosed and normal dentin. Methods. Silorane FiltekTM P90, FiltekTMZ250 XT in combination with the adhesive system AdperTM Single bond 2, and Amelogen® Plus in association with Peak Universal Bond® were tested. Fifteen normal and 15 fluorosed dentine disks were prepared per material. The shear bond strength test was performed using a universal machine. Results. One-way ANOVA revealed significant differences in bond strength between the tested composite resins. All tested materials had significantly different adhesion at the fluorosed and the nonfluorosed interface. FiltekTM Z250 XT and Silorane had lower adhesion values to fluorosed than to normal dentin. In contrast, Amelogen® Plus presented a better average resistance at the fluorosed interface. Conclusion. Amelogen® Plus presented a better average shear bond strength on the fluorosed dentine. FiltekTMZ250 XT showed the best adhesion forces and shear bond strength with sound dentine. Further studies are needed to better understand the sealing of these systems.


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