|Year : 2019 | Volume
| Issue : 2 | Page : 90-93
Evaluation and comparison of tensile bond strength of addition silicone impression material with different tray adhesives
Vasantha Vijayaraghavan1, Rupali Patil1, Seema Patil1, Pankaj Kadam1, S Bhuminathan2
1 Department of Prosthodontics and Crown and Bridge, Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital,
Pune, Maharashtra, India
2 Department of Prosthodontics and Crown and Bridge, Sree Balaji Dental College and Hospitals, Chennai, Tamil Nadu, India
|Date of Submission||02-Oct-2019|
|Date of Decision||29-Oct-2019|
|Date of Acceptance||31-Oct-2019|
|Date of Web Publication||3-Feb-2020|
Dr. Vasantha Vijayaraghavan
Department of Prosthodontics and Crown and Bridge, Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
Statement of Problem: Very few studies have been conducted on the comparative evaluation of bond strength of elastomeric impression material to custom tray material using two different universal adhesive systems.
Materials and Methods: A special mold was made for the fabrications of 24 samples of tray resin materials. They were divided into two main groups of 12. Perforations followed by adhesive application were done according to the grouping of samples. Polyvinyl siloxane material (medium body) was placed over the samples. A universal testing machine with a crosshead speed of 5 mm/min was used to determine the tensile bond strength of tray resin samples to medium body impression material by using different universal adhesives. Based on these values, Student's “t” test, group statistics, and ANOVA test were applied.
Results: By using analysis of variance, there was no significant difference between the strength of bonding of tray resin material and medium body addition silicone by different adhesive systems.
Conclusion: It was concluded that Medicept Universal tray adhesive system is as good as 3M™ universal tray adhesive system to achieve a good bond between tray resin and medium body addition silicone.
Keywords: Addition silicone; tensile bond strength; tray resin; universal tray adhesive
|How to cite this article:|
Vijayaraghavan V, Patil R, Patil S, Kadam P, Bhuminathan S. Evaluation and comparison of tensile bond strength of addition silicone impression material with different tray adhesives. Indian J Multidiscip Dent 2019;9:90-3
|How to cite this URL:|
Vijayaraghavan V, Patil R, Patil S, Kadam P, Bhuminathan S. Evaluation and comparison of tensile bond strength of addition silicone impression material with different tray adhesives. Indian J Multidiscip Dent [serial online] 2019 [cited 2020 Dec 3];9:90-3. Available from: https://www.ijmdent.com/text.asp?2019/9/2/90/277452
| Introduction|| |
A dimensionally accurate impression is essential for successful prosthodontic therapy. The advent of new materials and employment of correct technique has enabled achieving of an accurate impression. It has been established beyond doubt that the use of custom tray enhances the dimensional accuracy of an impression by helping to achieve uniform thickness of the impression material. An impression made with an elastic impression material may be securely attached to the tray by the use of tray adhesive for making a good impression. The distorted prosthesis obtained from impression material being pulled away from tray due to poor adhesion need not be overemphasized. Both manufacturer-recommended adhesive and universal adhesive are currently available. Studies showing good results in terms of bond strength between manufacturer-recommended adhesive and some universal adhesive are also found in literature. This study aims to compare the bond strength between medium body addition silicone and two brands of universal adhesive and explore the better among them in terms of bond strength. A tray resin material with holes simulating mechanical retention is used in the study for both the adhesives.
| Materials and Methods|| |
The total number of samples was 24. They were made into two groups of 12 each.
Fabrication of sample mold
Three metal dies were fabricated to prepare main tray, cover tray, and perforations in the tray. The main die was designed in such a way that it will produce a tray having 30/30 mm testing surface area with 2 mm depth and 10/10 mm borders. A cover tray die is designed in such a way that 40/40 mm tray is produced. A perforated die is prepared in such a way that it contains holes of 2 mm diameter and 5 mm in depth which are placed at a distance of 5 mm from each other.
All the resin blocks of acrylic resin (MP Sai Enterprises, Mumbai, Maharashtra, India), were prepared in an aluminum mold. The resin material was manipulated according to the manufacturer's instructions and packed into the mold. Lids were slid over the mold so that excess material came out from the center. Then, the threaded portion of the screw was inserted into the resin at the center. After the material set in completely, the lids were removed, the screws were tightened, and the block was removed. The same procedure was done for the cover trays expect screw insertion [Figure 1]. The samples were stored at room temperature for 24 h.,, The samples were perforated by using a perforated die and straight fissure bur no. 8 [Figure 2]. It was repeated for the cover trays.
Group A (control group)
Using a brush, a single thin layer of tray adhesive (3M™ ESPE VPS tray adhesive, 3M ESPE (USA)) was applied over the surface of acrylic resin trays and allowed to dry at room temperature for 15 min according to the manufacturer's instructions. The adhesive was confined to the tested surface. It was repeated for cover trays.
Group B (test group)
Using a brush, a single thin layer of Medicept (Extreme tray adhesive, Medicept UK) tray adhesive was applied over the surface of acrylic resin trays and allowed to dry at room temperature for 15 min according to the manufacturer's instructions. The same procedure of applying on cover trays was followed for this group also.
The impression material (Monophase Aquasil™, Aquasil Monophase (Dentsply/caulk, 78467, Kontanz, Germany)) was mixed according to the manufacturer's instructions. It was loaded on to the resin trays. Both the resin trays were approximated till the rims of the tray touch each other completely, and it was ensured that uniform 2 mm thickness of material was present between the block and fixture. Excess material which had flown out was cut with a scalpel.
When the material had set in completely, the sample was attached to a universal testing machine [Figure 3]. Each sample was tested under a crosshead speed of 5 mm/min. The maximum load at which material gets deboned was recorded. The tensile strength was calculated by dividing the maximum load by cross-sectional area. The tensile bond strength was recorded in MPa.
Tensile bond strength = F/A.
where F is the maximum force at which separation failure occurred in kgF, A is area of adhesion, i.e., area of the circle (3.14 × r2) in mm2, and r is the radius of the circle (i.e., r = diameter of circle/2, r = 15/2 = 7.5 mm).
| Results|| |
The analysis reveals that there is no statistically significant difference between the control material and test material. The level of significance was set at P < 0.05 [Table 1] and [Graph 1].
|Table 1: Comparison of tensile bond strength between elastomeric impression material and custom tray resin material using two universal tray adhesive systems|
Click here to view
Unpaired t-test was done. Level of significance = 5.
Descriptive quantitative data were expressed in mean and standard deviation.
Confidence interval was set at 95%, and probability of alpha error (level of significance) was set at 5%. Power of the study was set at 80%.
| Discussion|| |
Brown discussed the factors affecting the accuracy of an impression and stated that the selection of material and the technique used in making the impression are the two vital factors that are under the direct control of the operator. The bond strength of an impression material to tray is essential and is achieved with the use of various means of mechanical retention and/or chemical adhesion. To obtain an accurate impression, the impression material must be securely attached to the tray. This demands the use of tray adhesive to be applied on to the tray even though mechanical retention in the form of holes may be available sometimes. Each class of elastomeric impression materials has its own specific adhesives for application on impression trays. Both manufacturer-recommended tray adhesives and universal tray adhesives are available these days. Previous literature reported that the material–adhesive combination supplied by the manufacturer might not necessarily be the best. With the advent of the universal tray adhesive, many clinicians have started using this adhesive. The use of custom tray for making any final impression is justified for it ensures uniform thickness of impression material to be used. It ensures the precision and accuracy and minimizes errors due to dimensional changes. The impression adhesives used for silicone impression materials contain polydimethyl-siloxane and ethyl silicate. Polymethylsiloxane of adhesives bonds to the silicone impression material, whereas ethylsilicate forms hydrated silica that bonds to the impression tray material physically. The volatile solvent in the form of ethyl acetate reacts with the autopolymerizing tray material to create microporosites on the tray material so that the adhesive physically and mechanically bonds with it.
In this study, tray resin material was used. The adhesive used as control was 3M universal adhesive which is commonly used in routine practice. The newly introduced universal tray adhesive Medicept was used as the test material for this study. The optimal bond strength needed between tray adhesive and tray resin and between tray adhesive and polyvinylsiloxane impression material has not been stated in literature. Few study reports mention the tensile bonding strength between tray adhesive and tray material to be in the range of 0.13–2.1 MPa.,, The results of the present study revealed the mean value of 0.295–0.314 MPa, which is well within this range.
No study has been done on this material till date for tensile bond strength. Statistical analysis revealed that there is no statistically significant difference between 3M tray adhesive and Medicept tray adhesive [Table 1]. In other words, Medicept is as good as 3M in terms of tensile bond strength between medium body addition silicone and tray adhesive [Graph 1].
Medicept can be used as a tray adhesive in clinics for making elastomeric impressions like any other tray adhesive because it demonstrates bond strength at par with the commonly used universal tray adhesives with medium body addition silicone (Monophase Aquasil).
Scope of the study
This study was done under ideal conditions. The study could be conducted in a clinical scenario where saliva and oral temperature play a role in affecting the strength of the material.
| Conclusion|| |
This study was conducted to compare the tensile bond strength between medium body addition silicone (Monophase Aquasil) and two universal adhesives (3M and Medicept) applied on perforated tray resin material (MP Sai enterprises, Thane, Maharashtra, India). The following conclusions were drawn from the study:
- Medicept universal tray adhesive demonstrated tensile bond strength equivalent to 3M universal tray adhesive with medium body addition silicone (Monophase Aquasil)
- There is no statistically significant difference between 3M and Medicept tray adhesives in terms of bond strength as demonstrated by this study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]