scholarly journals Effect of Rebonding on the Bond Strength of Orthodontic Tubes: A Comparison of Light Cure Adhesive and Resin-Modified Glass Ionomer Cement In Vitro

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Monika Aleksiejunaite ◽  
Antanas Sidlauskas ◽  
Arunas Vasiliauskas

The purpose of this study was to determine the impact of different enamel preparation procedures and compare light cure composite (LCC) and resin-modified glass ionomer (RMGI) on the bond strength of orthodontic metal tubes rebonded to the enamel. Twenty human molars were divided into two groups (n=10). Tubes were bonded using LCC (Transbond XT) in group 1 and RMGI (Fuji Ortho LC) in group 2. The tubes in each group were bonded following manufacturers’ instructions (experiment I) and then debonded using testing machine. Then, the same brackets were sandblasted and rebonded twice. Before the first rebonding, the enamel was cleaned using carbide bur (experiment II) and before second rebonding, it was cleaned using carbide bur and soda blasted (experiment III). Mann–Whitney and Wilcoxon signed-rank tests showed no significant difference between RMGI and LCC bond strengths in case of normal bonding and rebonding, when enamel was cleaned using carbide bur before rebonding. Enamel soda blasting before rebonding significantly increased RMGI tensile bond strength value compared to LLC (p<0.05). LCC and RMGI (especially RMGI) provide sufficient bond strengths for rebonding of molar tubes, when residual adhesive from previous bonding is removed and enamel soda blasted.

Author(s):  
Anjna Sharma ◽  
Pankaj Mishra

ABSTRACT Aim To compare the compressive strengths of composite resins and resin-modified glass ionomer cements (RMGICs) at different times. Materials and methods A total of 36 samples were prepared, 12 samples of each group, composite resins Filtek Z 250, Filtek Z 350, and resin-modified glass ionomer cement. Compressive strengths of specimens were measured after 1, 24 hours, and 7 days. Test was carried out on a “Universal Testing Machine” with cross-head speed of 5 mm/min. Results There was a significant difference between all the three restorative materials. Analysis of variance showed that mean compressive strengths of Z 250 after 1, 24 hours were higher than Z 350 and RMGIC (p < 0.05). The mean compressive strengths were reduced after 7 days in all the three groups, but after 7 days, the values of Z 250 when compared with the Z 350 and RMGIC were higher. Conclusion The study demonstrated that compressive strengths of hybrid composite resins (Z 250) were significantly higher than that of nanocomposites (Z 350) and RMGIC. How to cite this article Sharma A, Mishra P, Mishra SK. Time-dependent Variation in Compressive Strengths of Three Posterior Esthetic Restorative Materials: An in vitro Study. Int J Prosthodont Restor Dent 2016;6(3):63-65.


2012 ◽  
Vol 23 (4) ◽  
pp. 379-386 ◽  
Author(s):  
Adriano Augusto Melo de Mendonça ◽  
Camila Fávero de Oliveira ◽  
Josimeri Hebling ◽  
Carlos Alberto de Souza Costa

This study evaluated the transdentinal cytotoxicity (TC) and the bond strength (BS) of a resin-modified glass-ionomer cement (RMGIC) applied to dentin covered with smear layer (SL) of different thicknesses. Forty dentin discs had thick (TSL) or thin (THSL) smear layer created on their occlusal side. In artificial pulp chambers, MDPC-23 cells were seeded on the pulpal side of the dentin discs and divided into five groups: G1TC: no treatment (control); G2TC: TSL + RMGIC; G3TC: THSL + RMGIC; G4TC: TSL removal + RMGIC; G5TC: THSL removal + RMGIC. After 24 h, cell metabolism and morphology were evaluated by the methyltetrazolium (MTT) assay and by scanning electron microscopy (SEM), respectively. For BS, the following groups were determined: G1BS: TSL removal + RMGIC; G2BS: THSL removal + RMGIC; G3BS: TSL + RMGIC; G4BS: THSL + RMGIC. Shear bond strength was tested to failure in a mechanical testing machine MTS (0.5 mm/min). Statistically significant difference was observed only between the control and experimental groups (Kruskal-Wallis, p<0.05). The metabolic activity of the viable MDPC-23 cells in G2TC, G3TC, G4TC and G5TC decreased by 54.85%, 60.79%, 64.12% and 62.51%, respectively. Mean shear bond strength values for G1BS, G2BS, G3BS and G4BS were 7.5, 7.4, 6.4 and 6.7 MPa, respectively, without significant difference among them (ANOVA, p>0.05). RMGIC presented moderate transdentinal cytotoxic effects. Maintenance or removal of smear layer did not affect the bond strength of RMGIC to dentin substrate.


2015 ◽  
Vol 40 (3) ◽  
pp. 304-312 ◽  
Author(s):  
NB Cook ◽  
SA Feitosa ◽  
A Patel ◽  
Y Alfawaz ◽  
GJ Eckert ◽  
...  

SUMMARY This study investigated the effect of nonrinse conditioners (ie, Ketac Nano Primer [KNP] and GC Self Conditioner [SC]) used as substrate pretreatment and their respective paste-paste resin-modified glass-ionomer cement (RMGIC) (ie, Ketac Nano [KN] and Fuji Filling LC [FF]) on microtensile bond strength to dentin and marginal sealing when compared with traditional RMGIC (ie, Photac Fil [PF] and Fuji II LC [FII]) used in association with polyacrylic acid (ie, Ketac Cavity Conditioner [KC] and GC Cavity Conditioner [CC]). A total of 192 extracted human molars were allocated into eight groups: KNP-KN, KC-KN, KNP-PF, KC-PF, SC-FF, CC-FF, SC-FII, and CC-FII. For microtensile bond strength, the teeth were sectioned to expose occlusal dentin and restored according to the group. After 24 hours the teeth were cut to yield nine beams per tooth (±0.8 mm2). Testing was done using a universal testing machine followed by failure mode classification. For microleakage testing, standardized cavity preparations were made on the buccal cementoenamel junction and restored according to the group. The teeth were thermocycled (500 cycles, 8°C to 48°C), sealed, immersed in methylene blue for 24 hours, and then assessed for microleakage using a stereomicroscope. Microtensile bond strengths in megapascals (mean±SE) were KNP-KN: 14.9 ± 1.6, KC-KN: 17.2 ± 1.5, KNP-PF: 31.2 ± 1.6, KC-PF: 26.2 ± 1.2, SC-FF: 23.6 ± 1.5, SC-FII: 31.2 ± 1.5, and CC-FII: 21.9 ± 1.5. Cervical margins showed more microleakage compared with occlusal margins. Overall, the use of nonrinse conditioners in association with traditional RMGICs demonstrated superior microtensile bond strengths to dentin when compared with the paste-paste RMGICs. Meanwhile, the association between polyacrylic acid (CC) and a traditional RMGIC (FII) led to the least microleakage for cervical locations when compared with all other groups.


2007 ◽  
Vol 77 (1) ◽  
pp. 113-116 ◽  
Author(s):  
Gabriella Rosenbach ◽  
Julio Pedrae Cal-Neto ◽  
Silvio Rosan Oliveira ◽  
Orlando Chevitarese ◽  
Marco Antonio Almeida

Abstract Objective: To evaluate the influence of enamel etching on tensile bond strength of orthodontic brackets bonded with resin-reinforced glass ionomer cement. Materials and Methods: The sample group consisted of 15 patients who had indications for extraction of four premolars for orthodontic reasons, equally divided into two different groups according to bracket and enamel preparation. Brackets were bonded in vivo, by the same operator, using a split mouth random technique: Group 1 (control), phosphoric acid + Fuji Ortho LC; Group 2, Fuji Ortho LC without acid conditioning. The teeth were extracted after 4 weeks using elevators. An Instron Universal Testing Machine was used to apply a tensile force directly to the enamel-bracket interface at a speed of 0.5 mm/min. The groups were compared using a Mann-Whitney U-test and Weibull analysis. Results: Mean results and standard deviations (in MPa) for the groups were: Group 1, 6.26 (3.21), Group 2, 6.52 (2.73). No significant difference was observed in the bond strengths of the two groups evaluated (P = .599). Conclusions: Fuji Ortho LC showed adequate shear bond strength and may be suitable for clinical use.


2015 ◽  
Vol 63 (1) ◽  
pp. 25-32
Author(s):  
Alcir ROSOLEN ◽  
Enrico Coser BRIDI ◽  
Roberta Tarkany BASTING

OBJECTIVE: The aim of this study was to evaluate in vitro the shear bond strength of metallic orthodontic brackets to enamel using different bonding materials followed by thermal cycling. METHODS: A fluid composite resin (Transbond XT / 3M Unitek) and a resin-modified glass ionomer (Fuji Ortho LC / GC America Inc.) were evaluated. Eighty sound human premolars were randomly divided into eight experimental groups (n = 10), according to the material used and the number of thermal cycles: zero, 1000, 2000 and 3000 cycles. Bracket bonding was performed on the buccal surface of the teeth. After 24 hours, they were subjected to thermal cycling at temperatures ranging between 5° C and 55° C for 15 seconds each immersion. Shear bond strength was performed using a universal testing machine with a chisel-type tip at a speed of 0.5 mm / min. The bond strength data was analyzed using two-way ANOVA. RESULTS: No difference on shear bond strength was observed regarding the number of thermal cycles for each specimen (p = 0.873). A significant difference was found in shear bond strength between the bonding materials (p = 0.022), with significantly higher values for Transbond XT regardless of the number of thermal cycles. CONCLUSION: The number of thermal cycles did not significantly affect the bond strength of the adhesive materials investigated. The bonding agent Transbond XT showed higher bond strength than Fuji Ortho LC regardless of the number of thermal cycles.


2015 ◽  
Vol 39 (2) ◽  
pp. 143-148 ◽  
Author(s):  
K Cantekin

The aim of the present study was to evaluate the bond strength of methacrylate-based (MB) composites, silorane-based (SB) composites, and glass-ionomer cement (GIC) in comparison to TheraCal and to compare those findings with the reference pulp capping material (MTA). Study design: A total of 90 acrylic blocks were prepared. Each of the blocks were prepared as 15 mm high and 10 mm diameter and the blocks had a 2 mm high and a 5 mm diameter central hole. In 45 of the samples, the holes were fully filled with TheraCal and in the other 45 samples, the holes were fully filled with MTA. The TheraCal and the MTA samples were randomly divided into 3 subgroups of 15 specimens each: Group-1: Methacrylate-based (MB) composite; Group-2: Silorane-based (SB) composite; and Group-3: Glass-ionomer cement (GIC). For the shear bond strength (SBS) test, each block was secured in a universal testing machine. After the SBS test, the fractured surfaces were examined under a stereomicroscope at ×25 magnification. Results: The analysis of variance that compared the experimental groups revealed the presence of significant differences among the groups (P &lt; 0.001). The highest (19.3 MPa) and the lowest (3.4 MPa) bond strength value were recorded for the MB composite-TheraCal and the GIC-TheraCal, respectively.There were significant differences in bond strength between the TheraCal and the MTA groups for the MB composite subgroup (P &lt; 0.001) and the SB composite subgroup (P &lt; 0.05); however, there was no significant difference in bond strength for the GIC subgroup (P ≯ 0.05). Conlusions: The results from this in vitro study suggest that the new pulp capping material, known as light-curable MTA, showed clinically acceptable and higher shear bond scores compared to MTA when used with the MB composite.


2014 ◽  
Vol 15 (6) ◽  
pp. 688-692 ◽  
Author(s):  
Sukumaran Anil ◽  
Farouk Ahmed Hussein ◽  
Mohammed Ibrahim Hashem ◽  
Elna P Chalisserry

ABSTRACT Objective The purpose of the current in-vivo study was to assess the effect of using 0.12% chlorhexidine (CHX) mouth rinse, before bonding, on shear bond strength of polycarbonate brackets bonded with composite adhesive. Subjects and methods Eighteen orthodontic patients with a mean age 21.41 ± 1.2 years, who were scheduled to have 2 or more first premolars extracted, were included in this study. Patients were referred for an oral prophylaxis program which included, in part, the use of a mouth rinse. Patients were divided into 2 groups, a test group of 9 patients who used 0.12% CHX gluconate mouth rinse twice daily and a control group of 9 patients who used a mouth rinse without CHX, but with same color. After 1 week, polycarbonate brackets were bonded to first premolars with Transbond XT composite adhesive. Premolars were extracted after 28 days and tested for shear bond strength on a universal testing machine. Student's t-test was used to compare shear bond strengths of both groups. Results No statistically significant difference was found in bond strengths’ values between both groups. The test group (with CHX) has mean shear bond strength of 14.21 ± 2.42 MPa whereas the control group (without CHX) revealed a mean strength of 14.52 ± 2.31 MPa. Conclusion The use of 0.12% CHX mouth rinse, for one week before bonding, did not affect the shear bond strength of polycarbonate brackets bonded with Transbond composite. Furthermore, these brackets showed clinically acceptable bond strength. How to cite this article Hussein FA, Hashem MI, Chalisserry EP, Anil S. The Impact of Chlorhexidine Mouth Rinse on the Bond Strength of Polycarbonate Orthodontic Brackets. J Contemp Dent Pract 2014;15(6):688-692.


2009 ◽  
Vol 03 (02) ◽  
pp. 127-134 ◽  
Author(s):  
Tancan Uysal ◽  
Mihri Amasyali ◽  
Alp Erdin Koyuturk ◽  
Deniz Sagdic

ABSTRACTObjectives: The aim of this in vitro study was to compare the efficacy of Amorphous Calcium Phosphate (ACP)-containing orthodontic composite and resin-modified glass ionomer cement (RMGIC) on enamel demineralization adjacent to orthodontic brackets evaluated by a new laser fluorescence device.Methods: Sixty extracted maxillary premolars were used in the present study. Twenty orthodontic brackets were bonded with ACP-containing orthodontic adhesive (Aegis-Ortho), 20 were bonded with RMGIC (Fuji Ortho LC) ad20 were bonded with Transbond XT composite as the control. All samples were then cycled for 21 days through a daily procedure of demineralization for 6 hours and remineralization for 17 hours. After this procedure, demineralization evaluations were undertaken by a pen-type laser fluorescence device (DIAGNO-dent Pen). Analysis ofvariance (ANOVA) and Tukey test was used for statistical evaluation, at P<.05 level.Results: According to ANOVA, significant demineralization variations (ΔD) were determined among groups (F=6.650; P<.01). The ACP-containing composite showed the lowest (mean: 8.98±2.38) and the control composite showed the highest (mean:12.15±3.83) ΔD, during 21 days demineralization process (P<.01). Significant difference was also observed between the ΔD scores of the RMGIC (mean: 9.24±2.73) and control (P<.05).No significant differences was found in preventive effects of ACP-containing composite and RMGIC (P<.05) against demineralization.Conclusions: The use of both ACP-containing orthodontic composite and RMGIC should be recommended for any at-risk orthodontic patient to provide preventive actions and potentially remineralize subclinical enamel demineralization. (Eur J Dent 2009;3:127-134)


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