The Effect of Peri-Bracket Excess Adhesive on Shear Bond Strength and Enamel–Adhesive Interface Morphology With Confocal Laser Scanning Microscopy: An In Vitro Comparative Study

2021 ◽  
pp. 232020682098739
Author(s):  
Banan Almashali ◽  
Nasser Alqahtani ◽  
Ahmed Almahdy
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Orthodontic Brackets ◽  
Confocal Laser ◽  
Adhesive Interface ◽  
Adhesive Remnant Index ◽  
Interface Characteristics ◽  
Group 1

Aim: To evaluate the effect of leaving excess adhesive around orthodontic brackets on the shear bond strength and on the enamel–adhesive interface characteristics. Materials and Methods: One hundred forty four human premolars were randomly divided into two groups according to the test performed. For the shear bond strength, 120 teeth were bonded with stainless steel orthodontic brackets using Transbond XT light cure adhesive composites. After positioning the bracket and before light curing, excess adhesive was removed according to the test group: group 1, all excess adhesive was removed (0 mm excess); group 2, 1 mm excess adhesive was left; group 3, 2 mm excess adhesive was left; shear bond strength was measured immediately and after three months of natural aging using a universal testing machine; and adhesive remnant index scores were also evaluated. For the enamel–adhesive interface characteristics, 24 teeth were bonded with stainless steel orthodontic brackets using Transbond XT light cure adhesive composites mixed with Rhodamine B fluorescent dye, excess adhesive was removed in the same manner according to the test groups, and teeth were evaluated using confocal laser scanning microscopy. Results: Time did not significantly affect the bond strength results ( P = .888) but the amount of excess adhesive significantly affected the results ( P < .05). Interaction terms were not significant ( P = .337). In both immediate and aged conditions, group 1 (0 mm excess) presented the highest bond strength results (MPa; P < .05). No significant difference was found in adhesive remnant index scores or enamel–adhesive interface characteristics. Conclusion: Excess adhesive around orthodontic bracket does not increase shear bond strength.

scholarly journals Analysis of Shear Bond Strength and Morphology of Er:YAG Laser-Recycled Ceramic Orthodontic Brackets

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ruo-qiao Han ◽  
Kai Yang ◽  
Ling-fei Ji ◽  
Chen Ling
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Laser Scanning ◽  
Er:Yag Laser ◽  
Statistical Significance ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Test Machine ◽  
Ceramic Brackets

Objective. The aim of this study was to compare the recycling of deboned ceramic brackets via an Er:YAG laser or via the traditional chairside processing methods of flaming and sandblasting; shear bond strength and morphological changes were evaluated in recycled brackets versus new brackets.Materials and Methods. 3M Clarity Self-Ligating Ceramic Brackets with a microcrystalline base were divided into groups subjected to flaming, sandblasting, or exposure to an Er:YAG laser. New ceramic brackets served as a control group. Shear bond strengths were determined with an Electroforce test machine and tested for statistical significance through analysis of variance. Morphological examinations of the recycled ceramic bracket bases were conducted with scanning electron microscopy and confocal laser scanning microscopy. Residue on the bracket base was analyzed with Raman spectroscopy.Results. Faded, dark adhesive was left on recycled bracket bases processed via flaming. Adhesive was thoroughly removed by both sandblasting and exposure to an Er:YAG laser. Compared with new brackets, shear bond strength was lower after sandblasting (p<0.05), but not after exposure to an Er:YAG laser. The Er:YAG laser caused no damage to the bracket.Conclusion. Er:YAG lasers effectively remove adhesive from the bases of ceramic brackets without damaging them; thus, this method may be preferred over other recycling methods.

scholarly journals Shear Bond Strength of Brackets Bonded to Enamel with a Self-Etching Primer

2009 ◽  
Vol 79 (1) ◽  
pp. 133-137 ◽  
Author(s):  
Matheus Melo Pithon ◽  
Antonio Carlos de Oliveira Ruellas ◽  
Eduardo Franzotti Sant'Anna ◽  
Márlio Vinícius de Oliveira ◽  
Luiz Antônio Alves Bernardes
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Orthodontic Brackets ◽  
Adhesive Properties ◽  
Time Points ◽  
Crosshead Speed ◽  
Adhesive Remnant Index ◽  
Significant Difference ◽  
Group 3 ◽  
Group 1

Abstract Objective: To evaluate bonding efficacy of activated Transbond Plus Self-Etching Primer (TPSEP) used at different time points with Transbond XT to bond metallic orthodontic brackets to bovine incisors. Materials and Methods: The inferior incisors of 210 bovines were randomly divided into seven groups (n = 30). TPSEPs were mixed, activated, and kept activated for 30 (group 30), 21 (group 21), 15 (group 15), 7 (group 7), 3 (group 3), or 1 (group 1) days before bonding, and in one group (group 0) TPSEP was used immediately after mixed. At day zero, incisors in each group were bonded in exactly the same way. After applying TPSEP, brackets were bonded with Transbond XT, according to the manufacturer's instructions. After 24 hours, shear bond strength (SBS) tests were performed for all samples at a crosshead speed of 0.5 mm/min, and the Adhesive Remnant Index was scored. Results: There were no significant differences between the SBS of groups 0, 1, 3, 7, and 15 (P &gt; .05) However, those groups had higher SBS (P &lt; .05) compared with groups 21 and 30. No significant difference (P &gt; .05) was observed between groups 21 and 30. Despite the decrease in SBS for groups 21 and 30, bond strength values were still satisfactory. Conclusion: After activation, the TPSEP mix can be stored for a period of 15 days without losing its adhesive properties.

scholarly journals Shear bond strength of orthodontic brackets to enamel after application of a caries infiltrant

2014 ◽  
Vol 85 (4) ◽  
pp. 645-650 ◽  
Author(s):  
Laura Mews ◽  
Matthias Kern ◽  
Robert Ciesielski ◽  
Helge Fischer-Brandies ◽  
Bernd Koos
Keyword(s):  
Statistical Analysis ◽  
Bond Strength ◽  
Shear Force ◽  
Shear Bond Strength ◽  
Orthodontic Brackets ◽  
Enamel Defects ◽  
Adhesive Remnant Index ◽  
Demineralized Enamel ◽  
Kolmogorov Smirnov ◽  
Bond Strengths

ABSTRACT Objective:  To examine differences in the shear bond strength of orthodontic brackets on differently mineralized enamel surfaces after applying a caries infiltrant or conventional adhesive. Materials and Methods:  A total of 320 bovine incisors were assigned to eight pretreated groups, and the shear force required for debonding was recorded. Residual adhesive was evaluated by light microscopy using the adhesive remnant index. Statistical analysis included Kolmogorov-Smirnov, analysis of variance (ANOVA), and Scheffé tests. Results:  The highest bond strength (18.8 ± 4.4 MPa) was obtained after use of the caries infiltrant. More residual adhesive and fewer enamel defects were observed on infiltrated enamel surfaces. Brackets on demineralized enamel produced multiple enamel defects. Conclusions:  Acceptable bond strengths were obtained with all material combinations. A caries-infiltrant applied before bracket fixation has a protective effect, especially on demineralized enamel.

scholarly journals Micromorphological analysis and bond strength comparison of two adhesives for different degrees of dental fluorosis

2020 ◽  
Author(s):  
Shuangfeng Liu ◽  
Yanxia Zhu ◽  
Tana Gegen
Keyword(s):  
Shear Strength ◽  
Bond Strength ◽  
Bonding Strength ◽  
Laser Scanning ◽  
Dental Fluorosis ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Cohesive Failure ◽  
Bonding System ◽  
Significant Difference

Abstract The objective of this study was to analyze morphologically the all-etching bonding system and self-etching bonding system for enamel with different degrees of fluorosis and evaluate the bond strength of each system. Teeth that were indicated for extraction owing to orthodontic or periodontal problems were selected. According to Dean’s index and the Thylstrup-Fejerskov index, 180 extracted teeth were divided into three groups of mild, moderate, and severe dental fluorosis (DF), with 60 teeth in each group. The teeth in each group were randomly divided into two subgroups (n = 30), which were then subjected to the all-etching bonding system (Prime & Bond NT) and self-etching bonding system (SE-Bond). Each group of adhesives was used to bond Z350 universal resin (3M) to the etched dental enamel. Tensile and shear tests were conducted to determine the bond strength. Subsequently, the fractured specimens were investigated using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The Prime & Bond NT was statistically significant for the tensile and shear strength of enamel with mild fluorosis (P < 0.05) but did not exhibit a significant difference for moderate and severe DF (P > 0.05). The SE-Bond was not statistically significant for the tensile and shear strength of mild, moderate, or severe DF (P > 0.05). The SEM and CLSM results reveal that the mild fluorosis enamel crystals were relatively dense, and a small amount of resin remained. The moderate fluorosis enamel crystals were loosely arranged, and the gaps were widened. The severe fluorosis enamel crystals were irregularly arranged. The disorder was aggravated, and the dentinal orifice was exposed by partial enamel exfoliation. The bonding strength of mild fluorosis enamel with the Prime & Bond NT was better than that with the SE-Bond, and cohesive failure was the most common mode of failure. Because there was no difference in the bonding strength of the SE-Bond for different degrees of DF, we recommend the use of the all-etching adhesive system in the clinical treatment of teeth with mild fluorosis.

Triacrylamide-Based Adhesives Stabilize Bonds in Physiologic Conditions

2022 ◽  
pp. 002203452110617
Author(s):  
F.S. de Lucena ◽  
S.H. Lewis ◽  
A.P.P. Fugolin ◽  
A.Y. Furuse ◽  
J.L. Ferracane ◽  
...  
Keyword(s):  
Bond Strength ◽  
Cross Sections ◽  
Laser Scanning ◽  
Adhesive System ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Gap Formation ◽  
Bond Stability ◽  
Occlusal Surfaces ◽  
Before And After

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey’s test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

scholarly journals Effect of Etching Procedures on the Adhesion of Biofilm-Coated Dentin

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2762
Author(s):  
Bo-Kyung Jeon ◽  
Chang-Ha Lee ◽  
A Reum Kim ◽  
Seung Hyun Han ◽  
Hyun-Jung Kim ◽  
...  
Keyword(s):  
Bond Strength ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Failure Modes ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Acid Etching ◽  
Dentin Surface ◽  
Biofilm Removal ◽  
Oral Biofilms

Oral biofilms coat all surfaces in the oral cavity including the exposed dentin surface. This study aimed to investigate biofilm removal by acid etching procedures and the effects of the residual biofilm on dentin surfaces on composite–dentin adhesion. Dentin discs were assigned to five groups: no biofilm formation (C); biofilm formation and no surface treatment (BF); biofilm formation and acid etching (BF-E); biofilm formation and acid etching followed by chlorhexidine soaking (BF-EC); and biofilm formation and rubbing with pumice, followed by acid etching (BF-RE). Biofilms were formed on saliva-precoated dentin discs by soaking the discs in Streptococcus mutans (S. mutans) suspension. Biofilm removal from the dentin surface was evaluated quantitatively and qualitatively by confocal laser scanning microscopy and scanning electron microscopy, respectively. To compare the bond strength of the biofilm-coated dentin discs with the surface treatments, specimens were assigned to four groups: no biofilm formation and acid etching (C-E); BF-E; BF-EC; and BF-RE. Assessments of the micro-shear bond strength and subsequent failure modes were performed. BF-E and BF-EC did not remove the biofilm, whereas BF-RE partially removed the biofilm attached to the dentin (p < 0.05). The bond strength of BF-RE was significantly higher than those of BF-E and BF-EC, but lower than that of C-E (p < 0.05). In conclusion, mechanical biofilm removal is recommended before etching procedures to enhance adhesion to the biofilm-coated dentin.

scholarly journals Effect of surface treatment of prefabricated teeth on shear bond strength of orthodontic brackets

2017 ◽  
Vol 22 (4) ◽  
pp. 47-52 ◽  
Author(s):  
Marina Cumerlato ◽  
Eduardo Martinelli de Lima ◽  
Leandro Berni Osorio ◽  
Eduardo Gonçalves Mota ◽  
Luciane Macedo de Menezes ◽  
...  
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Surface Treatments ◽  
Orthodontic Brackets ◽  
Positive Correlation ◽  
Diamond Bur ◽  
Group 2 ◽  
Group 1

ABSTRACT Objective: The aim of this in vitro study was to evaluate and compare the effects of grinding, drilling, sandblasting, and ageing prefabricated teeth (PfT) on the shear bond strength (SBS) of orthodontic brackets, as well as the effects of surface treatments on the adhesive remnant index (ARI). Methods: One-hundred-ninety-two PfT were divided into four groups (n = 48): Group 1, no surface treatment was done; Group 2, grinding was performed with a cylindrical diamond bur; Group 3, two drillings were done with a spherical diamond bur; Group 4, sandblasting was performed with 50-µm aluminum oxide. Before the experiment, half of the samples stayed immersed in distilled water at 37oC for 90 days. Brackets were bonded with Transbond XT and shear strength tests were carried out using a universal testing machine. SBS were compared by surface treatment and by ageing with two-way ANOVA, followed by Tukey’s test. ARI scores were compared between surface treatments with Kruskal-Wallis test followed by Dunn’s test. Results: Surface treatments on PfT enhanced SBS of brackets (p< 0.01), result not observed with ageing (p= 0.45). Groups II, III, and IV showed higher SBS and greater ARI than the Group 1 (p< 0.05). SBS was greater in the groups 3 and 4 (drilling, sandblasting) than in the Group 2 (grinding) (p< 0.05). SBS and ARI showed a positive correlation (Spearman’s R2= 0.57; p< 0.05). Conclusion: Surface treatment on PfT enhanced SBS of brackets, however ageing did not show any relevance. Sandblasting and drilling showed greater SBS than grinding. There was a positive correlation between SBS and ARI.

scholarly journals Rebonding of Orthodontic Brackets

2008 ◽  
Vol 78 (3) ◽  
pp. 531-536 ◽  
Author(s):  
Mona A. Montasser ◽  
James L. Drummond ◽  
Carla A. Evans
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Clinical Performance ◽  
Adhesive System ◽  
Orthodontic Brackets ◽  
Adhesive Systems ◽  
Adhesive Remnant Index ◽  
Acid Etch ◽  
The Mean ◽  
Self Etch

Abstract Objective: To compare rebonding of orthodontic brackets based on the hypothesis that no difference would be found between the adhesive systems with respect to shear bond strength, mode of failure, and clinical failure rates. Materials and Methods: The three adhesive systems included two self-etch primers (Transbond and M-Bond) and a conventional phosphoric acid etch (Rely-a-Bond). The sample size was 20 premolars for each adhesive system. The shear bond strength was tested 24 hours after bracket bonding with the bonding/debonding procedures repeated two times after the first debonding. Bond strength, adhesive remnant index (ARI), and failure sites were evaluated for each debonding. Statistical analysis consisted of a two-way analysis of variance (ANOVA) followed by Scheffè analysis. The clinical portion evaluated 15 patients over a 12-month period. Results: The mean shear bond strengths after the first, second, and third debondings for Rely-a-Bond were 8.4 ± 1.8, 10.3 ± 2.4, and 14.1 ± 3.3 MPa, respectively; for Transbond 11.1 ± 4.6, 13.6 ± 4.5, and 12.9 ± 4.4 MPa, respectively; and for M-Bond 8.7 ± 2.7, 10.4 ± 2.4, and 12.4 ± 3.4 MPa, respectively. After the three debondings the mean shear bond strength increased significantly from the first to the third debonding for Rely-a-Bond and M-bond (P ≤ .001), but did not change for Transbond (P = .199). Conclusions: The original hypothesis is not rejected. The two self-etching primers showing higher or comparable bond strength to the conventional phosphoric etch with less adhesive remnant on the enamel surface after the first debonding. With repeated bonding/debonding, the differences in the bond strength, ARI, and failure site were not significantly different. There was no difference in the clinical performance of the three adhesive systems (P = .667).

scholarly journals Correlation between Bond Strength to Dentin and Sealers Penetration by Push-Out Test and CLSM Analysis

2019 ◽  
Vol 30 (6) ◽  
pp. 555-562
Author(s):  
Maybell Tedesco ◽  
Marcelo Carvalho Chain ◽  
Wilson Tadeu Felippe ◽  
Ana Maria Hecke Alves ◽  
Lucas da Fonseca Roberti Garcia ◽  
...  
Keyword(s):  
Bond Strength ◽  
Laser Scanning ◽  
Regional Analysis ◽  
Kendall Test ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dentinal Tubules ◽  
Significant Difference ◽  
Ah Plus ◽  
Push Out

Abstract This study correlated the bond strength (BS) and dentin penetration of different sealers by push-out test and Confocal Laser Scanning Microscopy (CLSM) analysis. Forty-five root canals were prepared according to the crown-down technique and filled with gutta-percha associated to the following sealers (n=15): Endofill, AH Plus and MTA Fillapex. Five canals of each group were filled with the sealers added with 0.1% Rhodamine B dye. Next, the specimens were transversely sectioned and submitted to the push-out test (n=10) and CLSM analysis (n=5). The BS data showed the following means (MPa) and standard deviation: AH Plus (4.17±1.86); MTA Fillapex (3.13±1.96) and Endofill (2.10±1.03). Statistical analysis (two-way ANOVA, α=0.05) showed significant difference among sealers (p<0.001) and root canal thirds (p<0.001). The BS results of Endofill and MTA Fillapex were statistically similar (p>0.05), however, they were statistically different from AH Plus (p<0.001). The regional analysis of BS showed similarity between middle and apical thirds (p>0.05), and both were different from coronal portion (p<0.001). CLSM analysis verified tags formation in all groups and higher penetration of the specimens filled with AH Plus (p<0.05). The Kendall test (correlation between BS to dentin and sealer penetration into dentinal tubules) and the Pearson test (between failures pattern and sealer penetration into dentinal tubules) did not show correlation between the variables evaluated for all the tested sealers (p>0.05). AH Plus group had higher BS to dentin, and deeper tags formation than the other sealers. There was no significant correlation between BS and intratubular penetration of the tested sealers.

ASSESSMENT OF SHEAR BOND STRENGTH IN DIRECT AND INDIRECT BONDING TECHNIQUES.

2020 ◽  
pp. 11-14
Author(s):  
Sonali Mahadevia ◽  
Bhavya Trivedi ◽  
Arth Patel ◽  
Mauli Shah ◽  
Vaishali Gayakwad
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
T Test ◽  
Orthodontic Brackets ◽  
Indirect Bonding ◽  
Bond Strengths ◽  
Group 2 ◽  
Group 1

Objective: The aim of this study was to assess the shear bond strength of indirectly and directly bonded orthodontic brackets. Ninety Methods: extracted human premolars were collected and divided into two groups. In both the groups, direct bonding (group 1) and indirect bonding (group 2) a light-cured adhesive and primer (ENLIGHT LV) was used. Forty hours after bonding, the samples were De-bonded. Results: Mean shear bond strengths were 12.33, and 12.18 MPA for groups 1, and 2, respectively. The Independent Sample T-Test showed no signicant difference in mean bond strength between groups (P =.667). Conclusion: The result also showed that there was no statistically signicant difference in the shear bond strength between the direct and indirect bonding methods.

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