scholarly journals A comparative study on effect of different methods of recycling orthodontic brackets on shear bond strength

2020 ◽  
Author(s):  
Purna Prasad Khanal ◽  
Basanta Kumar Shrestha ◽  
Rajiv Yadav ◽  
Sanjay Prasad Gupta

Abstract Background: Recycling the old or debonded bracket is one possible alternative to the replacement with new bracket. The aim of this study was to evaluate and compare the effect of different methods of recycling stainless steel orthodontic brackets on shear bond strength.Methods: One hundred twenty human premolars extracted for orthodontic purpose were randomly divided into four groups. Standard MBT (0.022”) brackets, (Leone co., Sesto, Florentine, Florence, Italy) were bonded on buccal surface of all samples with light cured adhesive primer Orthosol (Enlight, Ormco corp., USA) using LED curing unit for 10 seconds. Group I was assigned as control and the brackets of Group II, Group III and Group IV were subjected to recycling by flaming (Gas microtorch: RS Pro, Nozzle, MT 790) ,flaming with sandblasting (Bio-Art sandblaster; Rua Teotônio Vilela, Brazil) and flaming with ultrasonic cleaning (Ultrasonic cleaning unit ,Confident dental equipments Ltd, India) respectively. The recycled brackets were rebonded and final debonding of all brackets was done with universal testing machine (AG-IC/100 KN, Shimadzu, Japan) at a crosshead speed of 0.5mm/min and shear bond strength (MPa) was determined. The adhesive remnant index was evaluated by stereomicroscope at 10X magnification (Olympus corp., Japan). Results: The highest shear bond strength was obtained with Group I (10.35 ± 0.46 MPa), followed by Group III (9.36 ± 0.55 MPa), Group IV (5.97 ± 0.66 MPa) and the least value was obtained with Group II (4.30 ± 0.55 Mpa). Significant differences among the groups were detected by analysis of variance. Tukey post hoc multiple comparison test showed that the shear bond strength of each group was significantly different from one another (p < 0.001). The Chi-square showed statistically significant differences in the adhesive remnant index of the 4 groups (p < 0.001). Conclusions: Shear bond strength of new brackets was significantly higher than that of the recycled brackets. Among recycled brackets, flaming with sandblasting provided adequate shear bond strength, flaming with ultrasonic cleaning provided borderline value for clinical use while flaming alone led to significantly lower value.

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Purna Prasad Khanal ◽  
Basanta Kumar Shrestha ◽  
Rajiv Yadav ◽  
Dr. Sanjay Prasad Gupta

Aim. The aim of this study was to evaluate and compare the effect of different methods of recycling stainless steel orthodontic brackets on shear bond strength. Methods. One hundred twenty human premolars extracted for orthodontic purpose were randomly divided into four groups. Standard MBT (0.022″) brackets were bonded on the buccal surface of all samples with light cured adhesive primers using an LED curing unit for 10 seconds. Group I was assigned as control, and the brackets of Group II, Group III, and Group IV were subjected to recycling by flaming, flaming with sandblasting, and flaming with ultrasonic cleaning, respectively. The recycled brackets were rebonded, and final debonding of all brackets was performed using a universal testing machine at a crosshead speed of 0.5 mm/min and shear bond strength was determined. Data were analyzed with descriptive statistics, ANOVA, and post hoc tests. The adhesive remnant index was evaluated using a stereomicroscope at 10X magnification. Results. The highest shear bond strength was obtained with Group I (10.35 ± 0.46 MPa), followed by Group III (9.36 ± 0.55 MPa) and Group IV (5.97 ± 0.66 MPa), and the least value was obtained with Group II (4.30 ± 0.55 Mpa). Significant differences among the groups were detected by analysis of variance. Tukey’s post hoc multiple comparison test showed that the shear bond strength of each group was significantly different from one another ( p < 0.001 ). Conclusions. Shear bond strength of new brackets was significantly higher than that of the recycled brackets. Among recycled brackets, flaming with sandblasting provided adequate shear bond strength, flaming with ultrasonic cleaning provided a borderline value for clinical use, and flaming alone led to a significantly lower value.


2021 ◽  
Author(s):  
Purna Prasad Khanal ◽  
Basanta Kumar Shrestha ◽  
Rajiv Yadav ◽  
Sanjay Prasad Gupta

Abstract Aim: The aim of this study was to evaluate and compare the effect of different methods of recycling stainless steel orthodontic brackets on shear bond strength.Methods: One hundred twenty human premolars extracted for orthodontic purpose were randomly divided into four groups. Standard MBT (0.022”) brackets were bonded on buccal surface of all samples with light cured adhesive primer using LED curing unit for 10 seconds. Group-I was assigned as control and the brackets of Group-II, Group-III and Group-IV were subjected to recycling by flaming, flaming with sandblasting and flaming with ultrasonic cleaning respectively. The recycled brackets were rebonded and final debonding of all brackets was done with universal testing machine at a crosshead speed of 0.5mm/min and shear bond strength was determined. Data were analyzed with descriptive statistics, ANOVA and post hoc test. The adhesive remnant index was evaluated by stereomicroscope at 10X magnification.Results: The highest shear bond strength was obtained with Group I (10.35 ± 0.46 MPa), followed by Group III (9.36 ± 0.55 MPa), Group IV (5.97 ± 0.66 MPa) and the least value was obtained with Group II (4.30 ± 0.55 Mpa). Significant differences among the groups were detected by analysis of variance. Tukey post hoc multiple comparison test showed that the shear bond strength of each group was significantly different from one another (p < 0.001). Conclusions: Shear bond strength of new brackets was significantly higher than that of the recycled brackets. Among recycled brackets, flaming with sandblasting provided adequate shear bond strength, flaming with ultrasonic cleaning provided borderline value for clinical use while flaming alone led to significantly lower value.


2016 ◽  
Vol 10 (01) ◽  
pp. 040-045 ◽  
Author(s):  
Hakan Colak ◽  
Ertugrul Ercan ◽  
Mehmet Mustafa Hamidi

ABSTRACT Objectives: Bulk-fill composite materials are being developed for preparation depths of up to 4 mm in an effort to simplify and improve the placement of direct composite posterior restorations. The aim of our study was to compare shear-bond strength of bulk-fill and conventional posterior composite resins. Materials and Methods: In this study, 60 caries free extracted human molars were used and sectioned parallel to occlusal surface to expose midcoronal dentin. The specimens were randomly divided into four groups. Total-etch dentine bonding system (Adper Scotchbond 1XT, 3M ESPE) was applied to dentin surface in all the groups to reduce variability in results. Then, dentine surfaces covered by following materials. Group I: SonicFill Bulk-Fill, Group II: Tetric EvoCeram (TBF), Group III: Herculite XRV Ultra, and Group IV: TBF Bulk-Fill, 2 mm × 3 mm cylindrical restorations were prepared by using application apparatus. Shear bond testing was measured by using a universal testing machine. Kruskal–Wallis and Mann–Whitney U-tests were performed to evaluate the data. Results: The highest value was observed in Group III (14.42 ± 4.34) and the lowest value was observed in Group IV (11.16 ± 2.76) and there is a statistically significant difference between these groups (P = 0.046). However, there is no statistically significant difference between the values of other groups. In this study, Group III was showed higher strength values. Conclusion: There is a need for future studies about long-term bond strength and clinical success of these adhesive and bulk-fill systems.


2012 ◽  
Vol 83 (4) ◽  
pp. 686-690 ◽  
Author(s):  
Ahmet Yalcin Gungor ◽  
Erhan Ozcan ◽  
Huseyin Alkis ◽  
Hakan Turkkahraman

ABSTRACT Objective: To evaluate the effects of different bleaching methods on the shear bond strength (SBS) of orthodontic brackets. Materials and Methods: Forty-five freshly extracted premolars were randomly divided into three groups (n  =  15 per group). In group I, bleaching was performed with the office bleaching method. In group II, bleaching was performed with the home bleaching method. Group III served as the control. Orthodontic brackets were bonded with a light cure composite resin and cured with an LED light. After bonding, the SBS of the brackets were tested with a Universal testing machine. Results: Analysis of variance indicated a significant difference between groups (P &lt; .001). The highest values for SBS were measured in group III (20.99 ± 2.32 MPa). The SBS was significantly lower in groups I and II than in group III (P &lt; .001). The lowest values for SBS were measured in group II (6.42 ± 0.81 MPa). SBS was significantly higher in group I than in group II (P &lt; .001). Conclusions: Both of the bleaching methods significantly affected the SBS of orthodontic brackets on human enamel. Bleaching with the home bleaching method affected SBS more adversely than did bleaching with the office bleaching method.


2015 ◽  
Vol 09 (02) ◽  
pp. 224-227 ◽  
Author(s):  
Shenbagakuttalam Anand ◽  
Ambrose Vedamanickam Rajesh Ebenezar ◽  
Nirupa Anand ◽  
Kothandaraman Rajkumar ◽  
Sekar Mahalaxmi ◽  
...  

ABSTRACT Objectives: To comparatively assess the micro shear bond strength (MSBS) of dentin bonded surface pre-treated zirconia ceramics. Materials and Methods: Zirconia blocks were sectioned into 50 cubical blocks. The blocks were further categorized into five groups (n = 10 each). Group I: No treatment was performed on zirconia samples; Group II: The zirconia samples were sand-blasted; Group III: Group II + etched with 9.8% of hydrofluoric (HF) acid for 60 s; Group IV: The sandblasted zirconia samples were selectively infiltrated with low fusing porcelain; and Group V: Group IV + etched using 9.8% HF acid gel. The zirconia specimens were then bonded to dentin samples, and the samples were tested for MSBS evaluation using universal testing machine. Results: The MSBS of all the four experimental groups shows greater value than group I. Among the experimental groups, group V and group IV do not show any statistical significant difference, whereas the mean MSBS of groups IV and V were statistically greater than group III and group II. However, groups I, II, and III do not show any statistical significant difference in mean MSBS values between them. Conclusion: Selective infiltration etching of zirconia ceramics provides the highest bond strength with resin cement.


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.


2021 ◽  
Vol 48 (4) ◽  
pp. 397-404
Author(s):  
Seung-Hee Woo ◽  
Jisun Shin ◽  
Joonhaeng Lee ◽  
Miran Han ◽  
Jong Soo Kim

The purpose of this study was to evaluate the effect of a hemostatic agent containing aluminum chloride on the shear bond strength of resin-modified glass ionomer cement (RMGIC) to the dentin of primary teeth. Thirty-six extracted non-carious human primary teeth were collected in this study. Dentin surfaces were cut and polished. The specimens were randomly divided into 4 groups; group I: RMGIC without conditioning; group II: polyacrylic acid (PAA), RMGIC; group III: aluminum chloride, RMGIC; group IV: aluminum chloride, PAA, RMGIC. All teeth were thermocycled between 5.0℃ and 55.0℃ for 5000 cycles. Fifteen specimens from each group were subjected to shear bond strength test and 3 specimens from each group were inspected using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy. The mean shear bond strength of each group was as follows: 4.04 ± 0.88 MPa in group I, 8.29 ± 1.40 MPa in group II, 1.39 ± 0.47 MPa in group III, 6.24 ± 2.76 MPa in group IV. There were significant differences among all groups (p < 0.001). SEM image of the dentinal tubules were partially exposed in group III and group IV. Fully exposed dentinal tubules were found in group II. In conclusion, aluminum chloride decreased the shear bond strength of RMGIC to dentin, regardless of PAA conditioning.


2014 ◽  
Vol 08 (02) ◽  
pp. 184-190 ◽  
Author(s):  
Dina Wafik Elkassas ◽  
Elham Mostafa Fawzi ◽  
Ahmed El Zohairy

ABSTRACT Objectives: This study was carried out to examine the effect of application of four different disinfecting agents on the micro-shear bond strength (μ-SBS) of an etch-and-rinse and self-etch adhesive systems. Materials and Methods: One hundred flat dentin surfaces of human molars were produced by wet grinding the buccal surfaces. Specimens were randomly assigned to five groups according to the disinfectant used: Group I: Control (no disinfectant); Group II: 5.25% sodium hypochlorite based; Group III: 2% chlorhexidine based (Consepsis), Group IV: 0.1% benzalkoniumchloride based (Tubulicid red) and Group V: 3% doxycycline based (Biopure, MTAD). Specimens were bonded using either Adper Single Bond 2 or Clearfil S3 Bond, which were employed according to the manufacturer's instructions. Resin composite microcylinders were bonded using Tygon® tubes for μ-SBS testing. The modes of failure were noted after visual examination using a binocular stereomicroscope at ×25 magnification. Failures were classified as adhesive, or mixed. μ-SBS results were analyzed using two-way ANOVA followed by Tukey's post-hoc test. Results: Dentin disinfectants tested significantly negated the bonding of Adper Single bond 2 and the groups were ranked; Group I > Group V = Group IV > Group II = Group III, meanwhile they enhanced significantly the μ-SBS values upon using Clearfil S3 Bond and were ranked; Group II > Group III = Group IV = Group V > Group I. Most failures were adhesive with the Adper single bond adhesive system. Mixed modes of failure were evident with Clearfil S3 bond. Conclusions: The disinfectants tested should not be used with Adper Single Bond 2 when applied before the etching step, However they could be used safely prior to bonding with Clearfil S3 Bond.


2020 ◽  
pp. 1-11
Author(s):  
Anip K. Roy ◽  
Govind N. Prasad ◽  
Tushar V. Bhagat ◽  
Saurabh Chaturvedi ◽  
Vishwanath Gurumurthy ◽  
...  

BACKGROUND: The increased strength of zirconia has resulted in its widespread application in clinical dentistry. Nevertheless, the fracture of veneering porcelains remains one of the key reasons of failure. OBJECTIVE: The objective of this study was to compare and analyze the influence of surface conditioning methods on the core-veneer bond strength of zirconia restorations. METHODS: Thirty specimens of zirconia core with sizes 10 × 5 × 5 mm were layered with porcelain of sizes 5 × 3 × 3 mm. On the basis of different surface conditioning methods, four groups were made: Group I: abrasion with airborne alumina particles of 110 μm size, Group II: sandblasting with silica coated alumina particles of 50 μm in size, Group III (modified group): alteration with a coating of zirconia powder prior to sintering, and Group IV (control group): metal core specimens. The shear force of all specimens was tested using a universal testing machine with a 0.5 mm/min crosshead speed. One-way analysis of variance (ANOVA) and Tukey’s post hoc pair wise comparison (p= 0.05) were performed to analyze the shear bond strength. A scanning electron microscope was used to assess the fractured specimens. RESULTS: A statistically significant difference was noted between the groups. The mean value of shear bond strength was 40.25 MPa for Group I, 41.93 MPa for Group II, 48.08 MPa for Group III and 47.01 MPa for Group IV. CONCLUSIONS: The modified zirconia group and control group demonstrated a significantly higher mean bond strength than that of Group I, where airborne particle abrasion was used. The scanning electron microscope showed that cohesive fracture in the porcelain veneers was the main problem of failure in altered zirconia. The modified zirconia specimens in Group III demonstrated significantly improved values of shear bond strength.


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.


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