scholarly journals Effect of CPP-ACP paste with and without CO2 laser irradiation on demineralized enamel microhardness and bracket shear bond strength

2017 ◽  
Vol 22 (4) ◽  
pp. 53-60 ◽  
Author(s):  
Nasrin Farhadian ◽  
Loghman Rezaei-Soufi ◽  
Seyed Farzad Jamalian ◽  
Maryam Farhadian ◽  
Shahrzad Tamasoki ◽  
...  

ABSTRACT Introduction: Many patients seeking orthodontic treatment already have incipient enamel lesions and should be placed under preventive treatments. The aim of this in vitro study was to evaluate the effect of CPP-ACP paste and CO2 laser irradiation on demineralized enamel microhardness and shear bond strength of orthodontic brackets. Methods: Eighty caries-free human premolars were subjected to a demineralization challenge using Streptococcus mutans. After demineralization, the samples were randomly divided into five equal experimental groups: Group 1 (control), the brackets were bonded without any surface treatment; Group 2, the enamel surfaces were treated with CPP-ACP paste for 4 minutes before bonding; Group 3, the teeth were irradiated with CO2 laser beams at a wavelength of 10.6 µm for 20 seconds. The samples in Groups 4 and 5 were treated with CO2 laser either before or through CPP-ACP application. SEM photomicrographs of a tooth from each group were taken to observe the enamel surface. The brackets were bonded to the buccal enamel using a conventional method. Shear bond strength of brackets and ARI scores were measured. Vickers microhardness was measured on the non-bonded enamel surface. Data were analyzed with ANOVA and Tukey test at the p< 0.05 level. Results: The mean shear bond strength and microhardness of the laser group were higher than those in the control group and this difference was statistically significant (p< 0.05). All groups showed a higher percentage of ARI score 4. Conclusion: CO2 laser at a wavelength of 10.6 µm significantly increased demineralized enamel microhardness and enhanced bonding to demineralized enamel.

2016 ◽  
Author(s):  
Bruna Raquel Zancope ◽  
Vanessa B Dainezi ◽  
Marinês Nobre-dos-Santos ◽  
Sillas Duarte, Jr ◽  
Vanessa Pardi ◽  
...  

Background. CO2 laser has been used to morphologically and chemically modify the dental enamel surface as well as to turn it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of CO2 laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2 laser (λ = 10.6 µM). Methods. For this in vitro study, it was employed 96 specimens of bovine enamel, which were divided into 2 groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by 1, 3 and 5 days under intermittent cariogenic condition in the irradiated and non irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and in fifth day, were evaluated by polysaccharides analysis, quantitative real time PCR as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test. Results. The mean of log CFU/ml obtained for the 1-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to CO2 laser, CFU/mL and CFU/ Dry Weight in 3 day was reduced significantly compared with control group. The difference in the genes expression (gtfB and gbpB) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with CO2 laser. Similar morphology was also visible with both treatments, however irradiated group revealed evidence of melting and fusion in the specimens. Conclusion. In conclusion CO2 laser irradiation modify the energy surface and disrupt the initial biofilm formation.


2018 ◽  
Vol 7 (2) ◽  
pp. 28-31
Author(s):  
Varunjeet Chaudhary ◽  
Sanad Singh Solanki ◽  
Varsha Yadav ◽  
Seema Lahoti

Objective: To evaluate the shear bond strength of stainless steel brackets bonded with fluoride-releasing composite resins, comparing effect of adhesion booster and conventional primer.Materials & Method: Sixty extracted premolars were subjected to bracket bonding with fluoride-releasing composite resin; which were bonded by randomly divided into two groups of bonding agents: Group 1- conventional primer as control group, Group 2- adhesion booster. After bonding, the samples were thermocycled (500 cycles) at 5ºC and 55ºC temperatures. After 48 hours they were subjected to shear bond strength testing in occluso-gingival direction, using an MTS 810 Universal Testing Machine with load speed of 0.5 mm/min.Result: Mean shear bond strength was significantly more in samples bonded with adhesion booster (14.792±3.805 Mpa) as compared to conventional primers (11.327±4.047 Mpa). There was statistically significant difference in shear bond strength between the groups (p=0.001).Conclusion: The use of the adhesion booster significantly increased the bond strength of bracket bonded with fluoride-releasing composite.


2015 ◽  
Vol 86 (2) ◽  
pp. 265-270 ◽  
Author(s):  
Moonyoung Lee ◽  
Georgios Kanavakis

ABSTRACT Objective:  To evaluate the bonding time, shear bond strength (SBS), and adhesive residue index (ARI) of APC(TM) Flash-Free bonding system. Materials and Methods:  Thirty-six extracted human maxillary premolars were randomly divided into three groups (12 per group) and used for this in vitro study: group 1, APC Flash-Free Adhesive Coated Appliance System; group 2, Clarity ADVANCED Ceramic Bracket pasted manually; group 3 (control group), 3M APC PLUS Adhesive prepasted brackets bonded with the extruded flash removed. Bonding time was measured using a stopwatch. Bond strength was measured using an Instron at a cross-head speed of 1 mm/min. The ARI was graded on a scale from 1 to 5. Repeated-measures analysis of variance and post hoc Tukey tests were used for statistical analysis. Results:  It took significantly (P &lt; .001) less time to bond in the APC Flash-Free Adhesive group (30.7 ± 3.3 seconds) compared with the control group (41.8 ± 4.0 seconds) and the manual group (39.2 ± 2.8 seconds). The APC Flash-Free Adhesive coated bracket had significantly (P &lt; .001) greater SBS (13.7 ± 2.2 MPa) compared with the control group (10.8 ± 2.0 MPa) and the manual group (10.4 ± 1.4 MPa). The ARI was significantly (P &lt; .001) greater with the APC Flash-Free Adhesive coated bracket compared with that of the other two groups. Conclusions:  Compared with other methods of bonding, the APC Flash-Free Adhesive Coated System can potentially reduce bonding time while increasing SBS.


2016 ◽  
Author(s):  
Bruna Raquel Zancope ◽  
Vanessa B Dainezi ◽  
Marinês Nobre-dos-Santos ◽  
Sillas Duarte, Jr ◽  
Vanessa Pardi ◽  
...  

Background. CO2 laser has been used to morphologically and chemically modify the dental enamel surface as well as to turn it more resistant to demineralization. Despite a variety of experiments demonstrating the inhibitory effect of CO2 laser in reduce enamel demineralization, little is known about the effect of surface irradiated on bacterial growth. Thus, this in vitro study was preformed to evaluate the biofilm formation on enamel previously irradiated with a CO2 laser (λ = 10.6 µM). Methods. For this in vitro study, it was employed 96 specimens of bovine enamel, which were divided into 2 groups (n = 48): 1) Control-non-irradiated surface and 2) Irradiated enamel surface. Biofilms were grown on the enamel specimens by 1, 3 and 5 days under intermittent cariogenic condition in the irradiated and non irradiated surface. In each assessment time, the biofilm were evaluated by dry weigh, counting the number of viable colonies and in fifth day, were evaluated by polysaccharides analysis, quantitative real time PCR as well as by contact angle. In addition, the morphology of biofilms was characterized by fluorescence microscopy and field emission scanning electron microscopy (FESEM). Initially, the assumptions of equal variances and normal distribution of errors were conferred and the results are analyzed statistically by t-test and Mann Whitney test. Results. The mean of log CFU/ml obtained for the 1-day biofilm evaluation showed that there is statistical difference between the experimental groups. When biofilms were exposed to CO2 laser, CFU/mL and CFU/ Dry Weight in 3 day was reduced significantly compared with control group. The difference in the genes expression (gtfB and gbpB) and polysaccharides was not statically significant. Contact angle was increased relative to control when the surface was irradiated with CO2 laser. Similar morphology was also visible with both treatments, however irradiated group revealed evidence of melting and fusion in the specimens. Conclusion. In conclusion CO2 laser irradiation modify the energy surface and disrupt the initial biofilm formation.


2013 ◽  
Vol 18 (3) ◽  
pp. 101-106 ◽  
Author(s):  
Sissy Maria Mendes Machado ◽  
Diego Bruno Pinho do Nascimento ◽  
Robson Costa Silva ◽  
Sandro Cordeiro Loretto ◽  
David Normando

OBJECTIVE: To evaluate in vitro the effects of tooth whitening using gel with Amorphous Calcium Phosphate (ACP) on the bond strength of metal brackets. METHODS: Thirty-six bovine incisors were sectioned at the crown-root interface, and the crowns were then placed in PVC cylinders. The specimens were divided into 3 groups (n = 12) according to whitening treatment and type of gel used, as follows: G1 (control) = no whitening; G2 = whitening with gel not containing ACP (Whiteness Perfect - FGM), G3 = whitening with gel containing ACP (Nite White ACP - Discus Dental). Groups G2 and G3 were subjected to 14 cycles of whitening followed by an interval of 15 days before the bonding of metal brackets. Shear bond strength testing was performed on a Kratos universal test machine at a speed of 0.5 mm/min. After the mechanical test, the specimens were assessed to determine the adhesive remnant index (ARI). The results were subjected to ANOVA, Tukey's test and Kruskal-Wallis test (5%). RESULTS: Significant differences were noted between the groups. Control group (G1 = 11.10 MPa) showed a statistically higher shear bond strength than the groups that underwent whitening (G2 = 5.40 Mpa, G3 = 3.73 MPa), which did not differ from each other. There were no significant differences between the groups in terms of ARI. CONCLUSION: Tooth whitening reduces the bond strength of metal brackets, whereas the presence of ACP in the whitening gel has no bearing on the results.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Andreas Hellak ◽  
Jennifer Ebeling ◽  
Michael Schauseil ◽  
Steffen Stein ◽  
Matthias Roggendorf ◽  
...  

Objective.The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond™and Scotchbond™) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™.Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces,n=30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120™testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P≤0.05).Results. Significant differences in SBS and ARI were found between the control group and experimental groups.Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.


2015 ◽  
Vol 49 (6) ◽  
pp. 565-574 ◽  
Author(s):  
Marcella Esteves-Oliveira ◽  
Nadine Witulski ◽  
Ralf-Dieter Hilgers ◽  
Christian Apel ◽  
Hendrik Meyer-Lueckel ◽  
...  

The aim of this in vitro study was to evaluate the effect of combined CO2 laser and tin-containing fluoride treatment on the formation and progression of enamel erosive lesions. Ninety-six human enamel samples were obtained, stored in thymol solution and, after surface polishing, randomly divided into 6 different surface treatment groups (n = 16 in each group) as follows: no treatment, control (C); one CO2 laser irradiation (L1); two CO2 laser irradiations (L2); daily application of fluoride solution (F); combined daily fluoride solution + one CO2 laser irradiation (L1F), and combined daily fluoride solution + two CO2 laser irradiations (L2F). Laser irradiation was performed at 0.3 J/cm2 (5 µs/226 Hz/10.6 µm) on day 1 (L1) and day 6 (L2). The fluoride solution contained AmF/NaF (500 ppm F), and SnCl2 (800 ppm Sn) at pH 4.5. After surface treatment the samples were submitted to an erosive cycling over 10 days, including immersion in citric acid (2 min/0.05 M/pH = 2.3) 6 times daily and storage in remineralization solution (≥1 h) between erosive attacks. At the end of each cycling day, the enamel surface loss (micrometers) was measured using a 3D laser profilometer. Data were statistically analyzed by means of a 2-level mixed effects model and linear contrasts (α = 0.05). Group F (-3.3 ± 2.0 µm) showed significantly lower enamel surface loss than groups C (-27.22 ± 4.1 µm), L1 (-18.3 ± 4.4 µm) and L2 (-16.3 ± 5.3 µm) but higher than L1F (-1.0 ± 4.4 µm) and L2F (1.4 ± 3.2 µm, p < 0.05). Under the conditions of this in vitro study, the tin-containing fluoride solution caused 88% reduction of enamel surface loss, while its combination with CO2 laser irradiation at 0.3 J/cm2 hampered erosive loss almost completely.


2015 ◽  
Vol 5 (2) ◽  
pp. 65-68
Author(s):  
Shruti Patil ◽  
Prajna Shetty

ABSTRACT Background The dentin desensitizers available for in-office application for prevention and/or treatment of post restorative dentinal hypersensitivity, act by blocking the open dentinal tubules. In doing so, they may influence the bond strength of the restorative resins. Thus, the aim of the study was to evaluate the effect of desensitizers on the shear bond strength of dentin adhesives and to check the extent of dentinal tubule occlusion caused by these desensitizers. Materials and Methods Sixty-four premolars were randomly divided into four groups of sixteen each. The middle depth dentin was exposed by on the buccal surface and was etched using 37% phosphoric acid and rinsed. They were assigned to, Group 1: Gluma desensitizer, Group 2: Vivasens desensitizer, Group 3: Gluma Comfort Bond and desensitizer, and Group 4: Adper Single Bond 2. Composite resin post of 2 mm in height and width were built on these specimens. The samples were then mounted in acrylic resin blocks. Universal testing machine was used to test the shear bond strength. The data were analyzed using one-way analysis of variance (ANOVA) and post hoc Tukey's test. Results The mean values of the shear bond strength were for: Group 1—18.61 ± 1.03 MPa, Group 2—17.53 ± 1.36 MPa, Group 3—22.63 ± 1.61 MPa and Group 4—23.12 ± 1.02 MPa. There was a statistically significant difference (p < 0.05) among the groups. Conclusion The use of dentin desensitizers’ influences bond strength between the tooth and the adhesive. Among the various agents, the single bottle system containing Gluma comfort bond and desensitizer had the best adhesion among the desensitizer groups. How to cite this article Patil S, Naik B, Shetty P. A Comparative Evaluation of Three Commercially Available Dentin Desensitizers on the Shear Bond Strength of Composite Resins: An in vitro Study. J Contemp Dent 2015;5(2):65-68.


2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Homa Farhadifard ◽  
Loghman Rezaei-Soufi ◽  
Maryam Farhadian ◽  
Parisa Shokouhi

Abstract Background At present, the demand for orthodontic treatment is on the rise. On the other hand, evidence shows that the bond strength of composite resins to old composite restorations is often unreliable. Therefore, the aim of this in vitro study was to assess the effect of different surface treatments on shear bond strength (SBS) of ceramic brackets to old composite restorations. Methods In this in vitro experimental study, 60 nano-hybrid composite discs were fabricated. For aging, the discs were incubated in deionized water at 37 °C for 1 month. Next, they underwent 4 different surface treatments namely acid etching with 37% phosphoric acid, sandblasting, grinding, and Er,Cr:YSGG laser irradiation. Ceramic brackets were then bonded to the discs and underwent SBS testing. Results The maximum mean SBS value was obtained in the grinding group (9.16 ± 2.49 MPa), followed by the sandblasting (8.13 ± 2.58 MPa) and laser (6.57 ± 1.45 MPa) groups. The minimum mean SBS value was noted in the control group (5.07 ± 2.14 MPa). Conclusion All groups except for the control group showed clinically acceptable SBS. Therefore, grinding, sandblasting, and Er,Cr:YSGG laser are suggested as effective surface treatments for bonding of ceramic orthodontic brackets to aged composite.


2021 ◽  
Author(s):  
Ladan Ranjbar Omrani ◽  
Saba Tohidkhah ◽  
Elham Ahmadi ◽  
Mahdi Abbasi ◽  
Reza Morvaridi Farimani

Abstract Background: The aim of the current study was to evaluate and compare the influence of Dycal, Lime-lite, Theracal LC, Biodentine, Resin-modified glass ionomer cement (RMGIC), and Activa Bioactive as the pulp capping material on the shear bond strength of resin composite to dentin.Methods: A total of 70 extracted caries-free molars were randomly assigned to seven groups. Six test groups were covered with various protective liners: Dycal (GD), Theracal LC (GT), lime-lite (GL), Activa Bioactive (GA), Biodentine (GB), RMGIC (GR). The control group (GC)received no liner pretreatment. Each sample was bonded to resin composite using the total-etch tetric N bond adhesive. The samples were then tested for shear bond strength using the universal testing machine at a cross-head speed of 1 mm/min until bond failure occurred. The data were analyzed using the one-way ANOVA test followed by the Tamhane post-hoc test for pairwise comparisons of the groupsResults: Independent of the type of the applied liner, all groups exhibited inferior SBS to dentine compared to the control group. GT and GR showed significantly higher shear bond strength than GB and GD, which showed the lowest shear bond strength. GL and GA also had significantly lower SBS results than GT. The mode of fracture was predominantly cohesive in GD, GB, and GT and adhesive in GA.Conclusion: This present study concludes that the bond strength of resin-composite to dentine can be affected differently using various types of liners.


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