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ORIGINAL RESEARCH
Year : 2022 | Volume
: 13
| Issue : 4 | Page : 136-138
Comparison of Shear Bond Strength of Three Luting Materials Used in Band and Loop Space Maintainer Cementation: An In Vitro Study
Sara Muhannad Zaidan1, Reem Atta Rafeeq2
1 Department of Pedodontics and Preventive Dentistry, College of Dentistry, University of Baghdad, Baghdad, Iraq
2 Department of Orthodontic Dentistry, College of Dentistry, University of Baghdad, Baghdad, Iraq
Correspondence Address:
Sara Muhannad Zaidan
Department of Pedodontics and Preventive Dentistry, College of Dentistry, University of Baghdad, Baghdad
Iraq
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/denthyp.denthyp_114_22
Introduction: Aim of this study is to compare shear bond strength of different luting materials used in fixed space maintainer cementation. Methods: Thirty intact extracted human third molars randomly divided into three equal groups: group A: RelyX luting 2 (resin modified glass ionomer); group B: TOTALCEM (self-adhesive resin cement/ dual cure); group C: Transbond plus (compomer). After bonding procedures, the samples were kept in distilled water at 37°C for 24 hours prior to the shear bond strength test. Data were analyzed blindly by one-way ANOVA test and the Tukey post hoc test using R software. Results: There were statistically significant differences between the three luting materials (P < 0.001). Conclusion: TOTALCEM showed significantly higher shear bond strength than RelyX luting 2 and Transbond plus. With respect to limitations of in vitro studies, long-term clinical studies required.
Keywords: Band and loop, compomer, dental cement, fixed space maintainer, resin modified glass ionomer, self-adhesive resin cement, shear bond strength
Early loss of primary molars tends to causes unfavorable drifting and loss of space.[1] Potentially, using space maintainers may prevent the need for later extractions and/or complicated orthodontic treatment.[2] The most popular type of space maintainer is the band and loop in case when a primary molar is extracted too early.[3] The band’s ability to remain on the tooth depends on how effectively the cement lute has fitted it. With the advent of the newest variations, numerous researches conducted in the past have demonstrated advancements in the field of dental cements.[4] Nevertheless, the objective of this study was to compare the shear bond strength of different commercially available luting materials used in cementation of fixed band and loop space maintainer.
Materials and MethodsStudy protocol was approved by the Ethics Committee of Baghdad University/College of dentistry (approval number: 555322, date: April 17). Thirty extracted human third molar were collected and stored in closed containers filled with distilled water and 0.1% concentration of thymol particles (v/w) (Zuhair lab, Baghdad, Iraq) to avoid dehydration and bacterial growth.[5] The teeth were randomly divided into three study groups. (Using www.calculator.net/random-number-generator.html). Sample size was determined using G power software 3.1.9.7 (http://www.gpower.hhu.de/) with 0.80 effect size f, 5% significance level, and a power of 95%.
The maximum mesiodistal and labiolingual width of the chosen molar bands were calculated in order to calculate band surface area using digital Vernier caliper (OEM, Beijing, China). The molar bands were held with a needle holder to avoid damage of bands during measuring the dimensions with figure pressure.[6]
Third molars were subjected to check up by using stereomicroscope (Kruss, Hamburg, Germany) using 20× magnification. Teeth with caries, cracks, restorations, and subjected to chemical pretreatment were excluded.[7] Orthodontic molar band with buccal tube and lingual cleat (IOS, Stafford, USA) was used in this study.[8]
The teeth were mounted vertically into different letter-coded acrylic blocks[9] (dimensions: 35 mm × 15 mm × 10 mm). The samples were stored in distilled water to avoid dehydration until bonding procedure would be achieved. After cleaning teeth with non-fluoridated pumice (i-Faste, Siauliai, Lithuania) for 10 seconds.[10] The teeth received the following treatments (according to manufacturer’s recommendations):
GROUP A: Relyx Luting 2 (3M, St. Paul, MN, USA) (resin modified glass ionomer) which was placed on cement paper pad and mixed by using cement spatula and applied on the inner surface of band and then light cured by using led type light cure device (Woodpecker, Guangxi, China) for 20 seconds from the occlusal surface.
GROUP B: TOTALCEM (ITENA, Villepinte, France) (self-adhesive resin cement/ dual cure) applied directly on the inner band surface with the aid of tip, which was provided inside the kit of the material, then light cured for 20 seconds.
GROUP C: Transbond plus Light Cure band adhesive (3M, St. Paul, MN, USA) (compomer) applied directly on the inner band surface the aid with of tip, which was provided inside the kit of the material then light cured for 20 seconds from the occlusal surface.
After those bonding procedures had been done, the samples were kept in distilled water at 37°C for 24 hours prior to the shear bond strength test.[11] The test was carried out in the laboratory of the department of materials engineering in the University of Technology, Baghdad, Iraq. The test was achieved using a universal testing machine. Each band had a pre-welded buccal tubes and lingual cleats to facilitate the attachment of band removing apparatus. The specimen was secured in the lower jaw of the testing machine and two orthodontic wires were used to achieve this procedure.[12] The two orthodontic wires were passed through the holes in the buccal tube and the lingual cleats. The wires joined together in and secured in the movable cross head. The testing machine started to move upward until the band was separated from the tooth. The applied force to remove the bands were measured in Newton (N), shear bond strength which was measured in megapascal (MPa) calculated by dividing the peak load values by the band surface area (mm2).
Data were analyzed by one-way ANOVA test and the Tukey post hoc test using R software (R Foundation for Statistical Computing, Vienna, Austria). Data analysts were blinded toward the different types of materials used.
ResultsThere were statistically significant differences between the three luting materials (P < 0.001) [Figure 1].
Figure 1 Box and whisker plot presented results of the shear bond strength related to the RelyX luting 2 (resin modified glass ionomer), TOTALCEM (self-adhesive resin cement/ dual cure), and Transbond plus (compomer). Also, P values related to post hoc comparisons using the Tukey method were showed. Discussion Although the stresses at the band–tooth contact are complicated, they can be primarily classified as shear or tensile stresses. So, in this study, the shear bond strength test was assessed.
The luting materials were applied on the enamel surfaces without any restorative materials in order to obtain data on the tooth structure’s pure bond strength without interference from restorative materials, for this reason sound teeth were selected.[12]
A comparison of mean shear bond strength required to deband the molar bands showed that TOTALCEM had significantly higher shear bond strength than both RelyX Luting 2 and Transbond Plus Light Cure band adhesive. This result agreed with study of Sabatini et al.[14] We found no statistically significance difference between RelyX Luting 2 and Transbond Plus Light Cure band adhesive which is agree with report of Millet et al., Agrawal et al., and Caglaroglu et al.[8],[15],[16] who also found that no significant difference between resin modified glass ionomer (RelyX Luting 2) and compomer (Transbond Plus Light Cure band). In contrast to results of this study Centekin et al.[2] found that resin modified glass ionomer had a significantly higher retentive force than compomer.
Water-absorption is an aim in the design of compomers[17] and soaking in water can cause their mass to expand by 2% to 3.5%. It has been established that neutralizing the carboxylic acid group is a necessary step in the process of water absorption. Neutralization is a relatively slow process since it depends on the degree of water diffusion. It is discovered that the process by which compomers absorb water to encourage neutralization has a negative impact on their physical characteristics. Contrary to traditional composite resins, which are known to absorb reasonable amount of water but this mechanism does not cause significant changes to the mechanical properties.[18]
It is noticeable that the greater retention was shown by self-adhesive resin cement (TOTALCEM) may due to its dual retention mechanism, micromechanical, and chemical retention between monomeric acidic groups and hydroxyapatite. It contains multifunctional monomers with phosphoric acid groups concurrently demineralize and infiltrate to enamel and dentin. The predominant setting reaction is the radical polymerization that can be started with light exposure or by the linking of cement monomers and the creation of high molecular weight polymers.[19]
However, with respect to limitations of in vitro studies, long-term clinical studies required for comparing bond strength of different types of letting materials. Since bands are used clinically for months to years, it would be useful to follow cement retention characteristics beyond 24 hours, and also assessment of bond strength under clinical conditions is mandatory due to many factors related to oral environment.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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