scholarly journals Debonding characteristics of orthodontic brackets subjected to intraoral stresses under different adhesive regimes: An in-vitro study

2020 ◽  
Vol 18 ◽  
pp. 228080001989964
Author(s):  
Khalid M Abdelaziz ◽  
Ibrahim Alshahrani ◽  
Muhammad Abdullah Kamran ◽  
Abdullah Alnazeh

Aim: To evaluate the effect of simulated intraoral hydraulic, thermal, and mechanical stresses on the debonding characteristics of orthodontic brackets under different adhesive regimes. Materials and methods: Groups of pre-coated (G1) and non-coated (G2) orthodontic metal brackets were bonded onto the buccal surfaces of 96 premolars using etch-and-rinse (SG1, n = 24) and self-etch (SG2, n = 24) primers. Twelve specimens (C1) from each subgroup were subjected to early debonding resistance tests, while the other twelve (C2) were used to test delayed debonding resistance after exposure to conditions simulating intraoral hydraulic, thermal, and mechanical stresses. The debonding resistance of the brackets was evaluated using a universal testing machine and the debonding patterns were micro-visualized to determine the adhesive remnant indexes of subgroups of specimens. Results: Within each group, the etch-and-rinse primer (SG1) resulted in higher debonding resistance than self-etch primers (SG2) ( p < 0.05), while there was no difference between non-stressed and stressed specimens ( p > 0.05). Within each category of test specimens, there was no difference between pre-coated (G1) and non-coated (G2) brackets ( p > 0.05). The tested specimens in all categories showed comparable adhesive remnant indexes. However, higher percentages of favorable scores (0 and 1) were obtained for all stressed specimens. Conclusions: Short-term cumulative intraoral stresses have no adverse effect on the debonding values of either pre-coated or non-coated brackets when either etch-and-rinse or self-etch primer is used for bonding. Exposure of the bonded brackets to different types of stress reflects favorable debonding patterns.

Author(s):  
Masoud Fallahinejad Ghajari ◽  
Amir Ghasemi ◽  
Mohammadreza Badiee ◽  
Zahra Abdolazimi ◽  
Alireza Akbarzadeh Baghban

Objectives: This study aimed to assess the microshear bond strength (MSBS) of Scotchbond Universal adhesive, used in self-etch and etch-and-rinse modes, to primary and permanent dentin at 24 hours and six months. Materials and Methods: A total of 88 composite micro-cylinders were divided into eight groups (n=11) as follows: (A) Etch-and-rinse, 24 hours, primary dentin; (B) Self-etch, 24 hours, primary dentin; (C) Etch-and-rinse, six months, primary dentin; (D) Self-etch, six months, primary dentin; (E) Etch-and-rinse, 24 hours, permanent dentin; (F) Self-etch, 24 hours, permanent dentin; (G) Etch-and-rinse, six months, permanent dentin; (H) Self-etch, six months, permanent dentin. The MSBS was measured by a testing machine at a crosshead speed of 0.5 mm/minute. Data were analyzed using three-way analysis of variance (ANOVA). Results: The mean MSBS was 12.3±2.3 MPa in A, 18.8±4.1 MPa in B, 11.9±3.7 MPa in C, 16±2.9 MPa in D, 19.1±2.7 MPa in E, 22.8±4.1 MPa in F, 16.2±2.6 MPa in G, and 17.2±4.4 MPa in H. In the self-etch mode, the MSBS was significantly higher than that in the etch-and-rinse mode (P<0.001). The MSBS in permanent teeth was significantly higher than primary teeth (P<0.001). At six months, the MSBS significantly decreased in all groups (P<0.001). Conclusion: The micro-shear bond strength of Scotchbond Universal adhesive decreases over time and depends on the type of tooth and the mode of application of the adhesive.


2020 ◽  
pp. 67-70
Author(s):  
Garima Gothwal ◽  
Hemant Kumar Sharma ◽  
Kusum Singh ◽  
Richa Sengar

Aim: The tear strength of three different types of elastomeric impression materials was measured after disinfection and sterilization. Material and Method: Dumb-bell shaped Tear strength specimens were prepared according to ISO 34-1 standardization. Ninety samples were prepared followed by disinfection and sterilization and tested with trouser piece method on Instron universal testing machine at a speed of 10 mm/min. One-way ANOVA, followed by Tukey post hoc test was used for statistical analysis. Results: No signicant difference was found when AFFINIS, SPEEDEX and AQUASIL were compared individually. When materials were compared with each other signicant difference was present, highest AQUASIL while SPEEDEX and AFFINIS almost alike. Conclusion: It was concluded that tear strength of AQUASIL was the highest. Disinfection and autoclaving had no signicant inuence on the three materials and showed adequate tear strength.


2020 ◽  
Vol 31 (2) ◽  
pp. 179-185
Author(s):  
Fernanda Borguetti Manfroi ◽  
Eduardo Miranda Ethur ◽  
Deise Caren Somacal ◽  
Tamara Paludo ◽  
Ana Maria Spohr

Abstract The aim was to evaluate, in vitro, the influence of pH cycling on microtensile bond strength (µTBS) and percentage of nanoleakage (%NL) in the dentin-adhesive interface. Flat dentin surfaces were obtained in 56 extracted third molars. The teeth were randomly divided into four groups (n=14): G1- Single Bond Universal (etch-and-rinse mode); G2- Single Bond Universal (self-etch mode); G3- Scotchbond Multi-Purpose; G4- Clearfil SE Bond. A block of composite was built on the adhesive area. Eight tooth/resin sets were cut parallel to the tooth’s long axis to obtain 48 beams (0.8 mm2) for each group. Half of the beams were submitted to four cycles of pH cycling (demineralizing solution for 6 h and remineralizing solution for 18 h). The samples were submitted to µTBS test in a universal testing machine. Six tooth/resin sets were cut parallel to the tooth’s long axis to obtain three slices of the central region (1.0 mm thickness). Half of the slices were submitted to pH cycling. The nanoleakage methodology was applied to obtain the %NL at the adhesive interfaces. According to two-way ANOVA, the interaction between factors (adhesive system x storage) was significant (p=0.0001) for µTBS and %NL. After pH cycling, there was a significant decrease in µTBS and a significant increase in %NL for all adhesives. The adhesives applied in the self-etch mode obtained lower %NL, differing significantly from the etch-and-rinse adhesives. It was concluded that the pH cycling negatively influenced the µTBS and %NL for all adhesives evaluated. However, self-etch adhesives allowed less %NL.


2015 ◽  
Vol 5 (1) ◽  
pp. 22-26
Author(s):  
Muzin Shahi Shaik ◽  
Snigdha Pattanaik ◽  
Sudhakar Pathuri ◽  
Arunachalam Sivakumar

Introduction: Bond strength is an important property and determines the amount of force delivered and treatment duration in orthodontics. Many light-cured bonding materials are being used; but it is required to determine the most efficient one withdesired bond strength. Objective: To determine and compare the shear bond strength of three visible light-cured composites (Transbond XT, Heliositand Enlight) and two self-cured composites (Rely-a-bond and Concise). Materials & Method: 100 extracted premolars were collected and randomly divided into 5 test groups of different adhesives. Brackets were bonded to the teeth in each test group with the respective adhesive according to the manufacturer’s instructions. Each specimen was debonded using Universal Testing Machine and the shear bond strength for each specimen was calculated. All the groups were compared by ANOVA one-way test. Results: There were statistically significant differences among the five groups (P<0.05). The shear bond strength of Enlight (13.92 ± 3.92) is similar to Transbond XT (14.30 ± 4.35). Conclusion: Light cure composites showed higher bond strength than self cure composites.


2020 ◽  
Vol 8 (10) ◽  
pp. 454-459
Author(s):  
Bhalla V. ◽  
◽  
K. Goud M. ◽  
Chockattu S. ◽  
Khera A ◽  
...  

Background:Dentin bonding is an ever-evolving field in adhesive dentistry. With the introduction of newer systems into the market, there is a crucial need to test their efficiency in terms of bond strength. Dual-cured adhesives in theory may provide for a better degree of conversion as compared to conventional light-cured adhesives .Thus, the aim of this study was to compare the shear bond strength of three different self-etch adhesives namely ClearfilSE bond (Kuraray), Tetric N Bond Universal (IvoclarVivadent) and Futura Bond DC (Voco) to dentin. Materials & Methods: Ninety extracted non-carious, intact human mandibular molar teeth were selected for this study. Each tooth was decoronated using a double-sided diamond disc with water coolant to a depth of 2mm from the cusp tip .The cut dentin surface was then abraded against 600-grit wet silicon carbide papers for 60 seconds to produce a uniform smear layer. The root portion of each tooth was mounted on a plastic ring using cold cure acrylic resin. Specimens were then divided into three adhesive groups of 30 teeth each, Group A: ClearfilSE Bond (Kuraray), Group B: Tetric N Bond Universal (IvoclarVivadent), Group C :Futura Bond DC (Voco). All bonding agents were used according to the manufacturers’ instructions, in combination with the resin composite Tetric N Ceram (IvoclarVivadent). The samples were thermocycled, followed by shear bond strength testing using a Universal testing machine (Hounsfield). Data were subjected to statistical analysis using one-way analysis of variance (ANOVA) (P<0.05) and Post hoc Tukey’s test for inter- and intra- group analysis respectively. Results: Clearfil SE Bond yielded the highest shear bond strength values (30.9 ±4.66 MPa) which were statistically significant, followed byTetric N Bond Universal group (29.8 ±4.34) and the lowest shear bond strength values were recorded for Futura Bond DC (18.2 ±3.13). Conclusion: Clearfil SE bond and Tetric N bond Universal can be considered as better options than Futura Bond DC.


2017 ◽  
Vol 18 (1) ◽  
pp. 34-38
Author(s):  
Mojtaba Abdollahi ◽  
Masoumeh Ebrahimi ◽  
Alireza Sarraf Shirazi ◽  
Faraneh Abdolhoseinpour

ABSTRACT Introduction One of the possible mechanisms for the gradual destruction of bond strength in dentin-resin interface, could be due to the demineralized unstable collagen matrix. Use of protease inhibitors, such as tannic acid (TA) could prevent destruction of collagen fibers. The aim of this study was to compare the TA effect on bond strength of etch and rinse and self-etch adhesive systems in the dentin of primary teeth. Materials and methods This in vitro study was done on 40 extracted primary molar teeth. The teeth were sectioned in the mesiodistal direction, and enamel of buccal and lingual surfaces was removed. Samples were randomly divided into four groups: Single bond (SB) + TA, SB, Clearfil SE Bond (CSB) + TA, and CSB. Then, Z250 and Clearfil AP-X composites were cured on the surfaces of SB and CSB groups respectively. After that, all samples were divided into aging and non-aging groups. For 3 months, samples were placed under 1,000 thermal cycles in aging group. Subsequently, the shear bond strengths of all groups were measured by the International testing machine, and failure mode was evaluated by an optical stereomicroscope. Data were analyzed with paired t-test and independent t-test. Results Tannic acid induced a significant reduction in the immediate bond strength of adhesive SB. Meanwhile, TA had no significant effect on shear bond strength of the CSB system. Conclusion Based on our findings, use of TA is not recommended with SB and CSB adhesives on primary teeth. Clinical significance Tannic acid may not be considered in resin restorations of primary teeth. How to cite this article Ebrahimi M, Sarraf Shirazi A, Abdolhoseinpour F, Abdollahi M. Effect of Tannic Acid on Bond Strength of Etch and Rinse and Self-etch Adhesive Systems in Dentin of Primary Teeth. J Contemp Dent Pract 2017;18(1):34-38.


2016 ◽  
Vol 6 ◽  
pp. 12-17
Author(s):  
Abdul Shahariyar C. A ◽  
Anurag D. Mahale ◽  
Kishore Kumar ◽  
Rohan Rai

Objective The aim of the current study was to determine the effects of casein phosphopeptide amorphous calcium-phosphate (CPP-ACP) complex, chlorhexidine fluoride mouthwash on shear bond strengths (SBSs) of orthodontic brackets. Materials and Methods About sixty extracted healthy human premolar teeth with intact buccal enamel were divided into two equal groups to which brackets were bonded using self-etching primers (SEPs) and conventional means respectively. These were further equally divided into three subgroups - (1) control (2) CPP-ACP (3) chlorhexidine fluoride mouthwash. The SBSs were then measured using a universal testing machine. Results SBS of the conventional group was significantly higher than the self-etching group. The intragroup differences were statistically insignificant. Conclusion CPP-ACP, chlorhexidine fluoride mouthwash did not adversely affect SBS of orthodontic brackets irrespective of the method of conditioning. Brackets bonded with conventional technique showed greater bond strengths as compared to those bonded with SEP.


Author(s):  
Sara Valizadeh ◽  
Aida Moradi ◽  
Mansooreh Mirazei ◽  
Hooman Amiri ◽  
Mohammad Javad Kharazifard

Objectives: The aim of this study was to compare the microshear bond strength (µSBS) of various adhesive systems to dentin. Materials and Methods: In this in vitro experimental study, 60 sound human third molars were divided into four groups. Dentin discs were prepared of middle-third dentin measuring 4 mm in diameter and 2 mm in thickness. Dentin surfaces were bonded with one of the four types of adhesives: (A) Single Bond (3M ESPE), Scotchbond Universal (3M ESPE) in etch and rinse (B) and self-etch (C) modes and (D) Clearfil SE Bond (Kuraray Noritake Dental). After the application of adhesive systems according to the manufacturers’ instructions, composite cylinders (Vit-l-escence) were bonded to dentin surfaces. The μSBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with one-way ANOVA and Tukey’s test (α=0.05). Results: The µSBS was the highest in self-etch Scotchbond Universal (15.8±6.08 MPa) followed by Clearfil SE Bond (15.24±4.6 MPa), etch and rinse Scotchbond Universal (11.68±4.07MPa) and Single Bond (11.24±3.74 MPa). A significant difference was only found between Single Bond and etch and rinse Scotchbond Universal groups (P=0.04). Conclusion: Based on the results of this study, application of Scotchbond Universal in self-etch mode provides a reliable bond to dentin.


Author(s):  
Sara Valizadeh ◽  
Aida Moradi ◽  
Mansooreh Mirazei ◽  
Hooman Amiri ◽  
Mohammad Javad Kharazifard

Objectives: The aim of this study was to compare the microshear bond strength (µSBS) of various adhesive systems to dentin. Materials and Methods: In this in vitro experimental study, 60 sound human third molars were divided into four groups. Dentin discs were prepared of middle-third dentin measuring 4 mm in diameter and 2 mm in thickness. Dentin surfaces were bonded with one of the four types of adhesives: (A) Single Bond (3M ESPE), Scotchbond Universal (3M ESPE) in etch and rinse (B) and self-etch (C) modes and (D) Clearfil SE Bond (Kuraray Noritake Dental). After the application of adhesive systems according to the manufacturers’ instructions, composite cylinders (Vit-l-escence) were bonded to dentin surfaces. The μSBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed with one-way ANOVA and Tukey’s test (α=0.05). Results: The µSBS was the highest in self-etch Scotchbond Universal (15.8±6.08 MPa) followed by Clearfil SE Bond (15.24±4.6 MPa), etch and rinse Scotchbond Universal (11.68±4.07MPa) and Single Bond (11.24±3.74 MPa). A significant difference was only found between Single Bond and etch and rinse Scotchbond Universal groups (P=0.04). Conclusion: Based on the results of this study, application of Scotchbond Universal in self-etch mode provides a reliable bond to dentin.


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