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| ORIGINAL ARTICLE |
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| Year : 2019 | Volume
: 9
| Issue : 1 | Page : 1-7 |
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Comparative evaluation of experimental chitosan gingival retraction cords with aluminum chloride and nonimpregnated retraction cords: An In vivo study
Aarushi Mahajan1, Roopa R Nadi1, Veena S Pai1, SN Joshi2
1 Department of Conservative Dentistry and Endodontics, Dayananda Sagar College of Dental Sciences, Bengaluru, Karnataka, India
2 Department of R and D, Everest Biotech, Bengaluru, Karnataka, India
| Date of Web Publication | 18-Feb-2019 |
Correspondence Address:
Aarushi Mahajan
Acer India (Pvt) Ltd., Embassy Heights 6th Floor, No. 13, Magrath Road, Bengaluru - 560 025, Karnataka
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jid.jid_63_18
 Abstract | | |
Aim: This study aimed to evaluate the efficacy of two chitosan gingival retraction cords with different cord thickness and to compare the effectiveness of chitosan cords against aluminum chloride gingival retraction and nonimpregnated retraction cord on different parameters. Materials and Methods: Fifty-two participants were selected and a total of 60 teeth were included which were divided randomly in the group of four. Experimental gingival retraction cords were colored yellow and black (braided, chitosan) and compared with aluminum chloride retraction cord and control nonimpregnated cord. Size for yellow chitosan cord and aluminum chloride was 00, and for black chitosan cord and control was 000. A total of four retraction cords were available for evaluation. Cords were inserted in gingival crevice with cord packer and left for 10 min. Results: There was no significant difference between the two experimental cords, but a significant difference with aluminum chloride cord showing better results with only two of the parameters, that is, the ease of packing the cord and fraying of cords. With nonimpregnated cord, there was a significant difference in hemostasis, sulcus widening, dry sulcus, and amount of bleeding at removal where all the other three cords were better than nonimpregnated cord. Conclusion: There was no statistically significant difference with respect to both the chitosan gingival retraction cords in all the criteria and with aluminum chloride cord except for fraying of cord. Both the experimental cords were superior to that of nonimpregnated cord with respect to all the criteria except for ease of packing the cord.
Keywords: Aluminum chloride, chitosan, gingival cord, hemostasis
How to cite this article:
Mahajan A, Nadi RR, Pai VS, Joshi S N. Comparative evaluation of experimental chitosan gingival retraction cords with aluminum chloride and nonimpregnated retraction cords: An In vivo study. J Interdiscip Dentistry 2019;9:1-7 |
How to cite this URL:
Mahajan A, Nadi RR, Pai VS, Joshi S N. Comparative evaluation of experimental chitosan gingival retraction cords with aluminum chloride and nonimpregnated retraction cords: An In vivo study. J Interdiscip Dentistry [serial online] 2019 [cited 2023 Mar 30];9:1-7. Available from: https://www.jidonline.com/text.asp?2019/9/1/1/252528 |
| Clinical Relevance to Interdisciplinary Dentistry | |  |
- Concerned with isolation techniques associated with restorative procedures and impression making, various isolation techniques are put forth in practice
- One method of gingival retraction by cord with various clinical aspect of hemostasis, sulcus widening, material handling, ease of use, dryness of sulcus, etc., is considered
- Chitosan being a biocompatible, with no cytotoxicity and with a hemostatic action is used in order to eliminate the use to harmful chemicals.
| Introduction | | |
Ahealthy coexistence of restoration and the surrounding periodontium should be the ultimate aim of any fixed prosthodontic or a direct or indirect restorative treatment.
The relationships between prosthetic crowns and the surrounding hard and soft tissue should be considered crucial for long-term success. The placement of margin can be supragingival, equigingival, or subgingival; however, that decision must be based on the situation. Several studies suggested that supragingival margins were preferable. Nevertheless, there are clinical situations that require restorations with subgingival margins.[1]
In cases where the finish line is located subgingivally, a tissue retraction is deemed mandatory before impression taking in order to clearly expose the prepared surfaces of the tooth.[2]
Most authors recommend that when supragingival margins are not feasible, restorative margins should be placed at least 3 mm from the alveolar crest, thus providing adequate biologic width even when the restoration margins are placed 0.5 mm within the gingival sulcus.[3]
Dealing in terms of general operative treatment procedures, gingival tissue management can be related to various techniques applied in order to displace these tissues from the proposed operating site and one such method is with the help of gingival retraction cord.
The purpose of gingival retraction is to place the tissue away from preparation, for hemostasis and to produce well-recorded margins for good marginal fit.
According to Shillingburg, the three main criteria for a gingival retraction material are as follows:
- Effectiveness in gingival displacement and hemostasis
- Absence of irreversible gingival damage
- Paucity of untoward systemic effects.
Laufer et al. suggested that 0.2 mm sulcular width is obligatory for enough thickness of material to be there at margins of impressions so that they can endure tearing/distortion on removal of impression.[4]
The means of accomplishing these objectives are – physiomechanical, chemical, electrosurgical, and surgical means.
Mechanical methods were the first methods introduced for moisture control,[5],[6],[7] among them gingival retraction cord is the most popular.[7],[8] However, plain cords not moistened with suitable medicaments generally are not able to control hemorrhage effectively,[9] and greater sulcular displacement happens when mechanical and chemical methods are combined, such as retraction cords impregnated with hemostatic agents.[5],[7],[10]
Chemical methods include a variety of chemical solutions and gels acting as astringents or hemostatic agents.[7],[11] Moreover, surgical methods such as electrosurgery and laser are alternative methods when hemorrhage is more serious or when soft-tissue removal and displacement are also required.[7],[12],[13]
The combination of chemical and mechanical methods or chemomechanical methods is the most popular retraction technique today[14],[15],[16] for which gingival retraction cord can be used which is a readymade cotton or synthetic woven cords, some have metallic or resin wire wrapped around them to assure their compactness and immobility.
| Materials and Methods | | |
Ethics
The procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional or regional) and with the Helsinki Declaration of 1975, as revised in 2000.
Selection of study population
The study population was selected from the patients visiting the Department of Conservative Dentistry and Endodontics, Dayananda Sagar College of Dental Sciences, for the treatment of prostheses such as single crown or fixed partial dentures. Participants were from any background and from both genders with good health, having healthy periodontium and gingival index of score 0, and also willing to give a written informed consent.
Participants were excluded with any skin diseases, allergic to chitosan and aluminum chloride, or any pregnant and lactating women. After all the inclusion and exclusion criteria, a total of 52 participants were selected which were divided randomly in the group of four. It was made sure that each group had 15 teeth to carry out the study. There were eight participants who had two teeth for the gingival retraction.
Subjects and methods
Experimental gingival retraction cords were colored yellow (braided, chitosan) and black (braided, chitosan) and compared with 0.5 mg ± 0.10 mg/inch aluminum chloride retraction cord and control nonimpregnated cord.
Size for yellow chitosan cord was 00, for black chitosan cord – 000, aluminum chloride – 00, and control – 000. A total of four retraction cords were available for evaluation [Table 1].
Group 1 was control group where nonimpregnated cord was used, Group 2 with aluminum chloride cord, Group 3 – yellow color chitosan-impregnated cord, and Group 4 – black color chitosan-impregnated cord.
Tooth was evaluated for gingival and periodontal status with sulcus depth of 1–2 mm with the help of Williams' periodontal probe.
Cords were inserted in the gingival crevice with the use of cord packer or blunt periodontal probe and left for 10 min before taking the impression. The experimental retraction cords were not immersed in any solutions or medicaments before insertion.
After removal of gingival retraction cords, clinical performance was ranked.
Six criteria were formulated to evaluate the clinical performance of retraction cords:
- How easily was cord packed in a gingival sulcus?
- Did the cord fray during placement?
- How rapidly did hemostasis occur?
- How much did the gingival sulcus dilate?
- Was bleeding evident after removal of cords?
- Did the gingival sulcus remain dry after removal of cord?
The scoring criteria were based on [Table 2] in order to analyze the effectiveness of retraction cord.
| Results | | |
Comparing the four cords, there was no significant difference between the two experimental cords [Table 3], [Table 4] and [Figure 1], [Figure 2] but when compared with aluminum chloride cord, there was a significant difference with only two of the parameters that is the ease of packing the cord and fraying of cords where aluminum chloride cord was better in both aspects [Table 4] and [Graph 1], [Graph 2]. Comparing the cords with nonimpregnated cord, there was a significant difference in hemostasis, sulcus widening, dry sulcus, and amount of bleeding at removal where all the other three cords were better than nonimpregnated cord [Table 4] and [Graph 3], [Figure 3]. | Table 3: Comparing the mean scores of different parameters among the study cords
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 | Table 4: Multiple comparison between the groups using Mann-Whitney post hoc analysis
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| Discussion | | |
Gingival retraction is an important aspect in the field of restorative and prosthetic procedures. Effective gingival retraction before taking an impression or restoration without damaging periodontal tissues is very important in long-term success of any restorations.
Gingival displacement's three-pronged goals are to have adequate bulk flow of material into the sulcus, to accurately record margin details, and to prevent impression material tear on retrieval from the gingival sulcus.[8] Gingival tissue usually returns to their original position because of the gingival cuff elasticity and the rebound forces of the compressed adjacent attached gingiva.[17]
The chemomechanical method of gingival displacement is the most widely used category[10] where a cord impregnated or soaked in a medicament helps to reduce bleeding, and sulcular fluid seeping from the sulcus is placed in the gingival sulcus to bring about reversible gingival displacement. These chemicals may or may not have hemostatic actions.
Various chemical agents with varying degrees of safety and effectiveness are available such as aluminum potassium sulfate (alum), aluminum chloride, epinephrine, zinc chloride, ferric sulfate, and sympathomimetic amines.
However, these preferred chemomechanical agents have their limitations, wherein aluminum chloride has less vasoconstriction than epinephrine with the risk of sulcus contamination, and it also modifies the surface detail reproduction and most importantly inhibits the set of polyvinyl siloxane and polyether impression.[17]
In a study conducted on dogs by Shaw DH and Krejci RF, no additional inflammation in gingival crevices was seen when diluted aluminum chloride (0.033%) was used compared with the concentrated solutions (60%), which caused severe inflammation and necrosis.[18]
There have been concerns over the use of racemic epinephrine-impregnated cords due to the elevation of blood pressure and increase in heart rate,[6],[8],[10] and no benefits have been recognized over other nonimpregnated cords.[19]
Harrison[20] compared plain cord, cord impregnated with two concentrations of epinephrine plus zinc chloride, and cord impregnated with 100% alum. Cords that contained zinc chloride at 8% and 40% concentrations caused severe tissue destruction, while the other materials brought about reversible injury. Both 8% epinephrine and 100% alum were effective in the control of moderate bleeding.
To overcome these limitations, a biocompatible agent, chitosan, with its hemostatic property to overrule the bleeding gingiva is studied as a chemomechanical agent to retract the gingiva, control moisture, and inhibit gingival bleeding.
In our study, we have used knitted retraction cord nonimpregnated 000 size as a control group, knitted retraction cord with 0.5 mg ± 0.10 mg/inch impregnated aluminum chloride 00 size as Group 2, Group 3 with 000 size braided yellow chitosan cord, and Group 4 as 00 size black chitosan cord.
For these four cords, six criteria were kept forth to evaluate the effectiveness of cord's actions, that is, ease of packing the cord, fraying of cords, hemostasis by cord, widening of the sulcus, bleeding on the removal of cord, and the dryness caused by the cord.
The displacement cord along with the chemical agent of choice is packed into the sulcus using a Fischer cord packing instrument and left in place for a period of 4–8 min and then removed. This usually brings about the desired gingival displacement.
Gingival retraction cords can be knitted, braided, or twisted in a variety of configurations to provide for different diameters and thicknesses. Clinician preference to braided cords relates to their tight and consistent weave. Braided cords are easier to place in the gingival sulcus with packing placement instruments because they are solid and can be pushed to place.
Knitted cords have increased in popularity which when saturated with astringents and when placed in the gingival sulcus expand creating a physical effect of enlarging the sulcus for access for impressions or to displace the gingival tissues when placing direct restorative materials. Furthermore, the unique knitted weave minimizes unraveling and fraying after cutting and during cord placement.[14],[21]
When comparing the experimental chitosan cords with the aluminum chloride in relation to packing of cord and its fraying while placing, there was a significant difference wherein aluminum chloride cord showed better placement into the sulcus. This could be explained by the use of knitted cords for the aluminum chloride retraction when compared with braided chitosan cords. Both the chitosan cords did not show any difference when compared regarding these two parameters. Yellow chitosan cord was also less efficient when compared with the nonimpregnated cord with respect to fraying of the cord.
Control of hemorrhage is one of the challenging situations dentists confront during deep cavity preparation and before impressions or cementation of restorations. Nonmedicated simple cords are safe, but they are not proper option to control bleeding. Cord pressure cannot stop the gingival bleeding by itself[22] and in more than 50% of cases bleeding occurs after removing the cord.[15]
Astringents, such as alum or aluminum potassium sulfate (Kal[SO4]2), AlCl, and zinc chloride, are substances that act by precipitating proteins on the superficial layer of mucosa and make it mechanically stronger.
Al2 Cl3 and ferric sulfate are preferred astringents among dentists because of minimum tissue damage[14],[23] and also ease of use and effective results.[9]
Chitosan retraction material was selected because it is an absorbing, hemostatic material along with the advantage of antimicrobial activity, nontoxicity, and biocompatibility.[24]
When comparing our experimental chitosan cords with aluminum chloride-impregnated cord, there was no significant difference in hemostatic action, bleeding at removal, and dry sulcus. Between chitosan gingival cords, there was no significant difference in any of the above parameters. Nonimpregnated cords were unavailing regarding hemostasis and bleeding at removal. Its ineffectiveness could be due to its nonimpregnation with any of the hemostatic agent.
The main cause of hemostatic effect of chitosan is related with the platelet adhesion, aggregation, and activation of intrinsic blood coagulation.[25] Based on the scanning electron microscope morphological evaluation, platelets were more strongly attached on the surface of chitin and chitosan particles with an elongated process. Platelets were attached and bound to each other by forming an aggregated mass in irregular shapes.[26] Furthermore, chitosan can generate intracellular signal reactions that activate glycoprotein IIb/IIIa and discharge thromboxane A2/ADP. These signals elevate platelet spreading and strengthen the stability of adhesion.[27]
Widening of gingival sulcus is often required in order to carry out the principles of cavity preparation, restoration, crown preparation, and impression taking. About 0.2 mm sulcular width is obligatory to perform these procedures.[28]
Sulcus widening was checked by placing the Williams' probe within the sulcus and analyzing the free pass of the probe within 1 mm of the vertical height. For nonimpregnated cord, the sulcus widening was insignificant, whereas aluminum chloride and both the chitosan cords showed better-dilated sulcus with no significant difference among them. Aluminum chloride cord with kitted configuration has the ability to expand when wet opening up the sulcus greater than the original diameter of the cord.[14],[21] Chitosan cords, even though were braided, showed better sulcus widening that could be due to the absorbing nature of the chitosan itself. In addition, the cords are needed to be placed for 4–6 min at least to get the appropriate sulcus width. Keeping the chitosan cord for more time also would not hamper the tissue due to its biocompatibility and nontoxicity, thus giving a benefit of using these cords.[24]
In brief, when comparing the experimental chitosan cords[29] with aluminum chloride impregnated cord, there was no significant difference in hemostatic action, bleeding at removal, dry sulcus, and widening of sulcus, thus making these experimental chitosan cords equivalently good as aluminum chloride cords in hemostasis. Between the chitosan gingival cords, there was no significant difference in any of the criteria.
It is pertinent to put forth our observation with regard to fraying of these experimental cords which further led to the difficulty in packing of these cords into the gingival sulcus. This could be due to the use of braided cords instead of knitted ones.
Hence, it can be concluded that the experimental chitosan gingival retraction cords are equally effective in ceasing the bleeding from the gingival sulcus with the further enhancement to the dry and widened sulcus when compared with aluminum chloride-impregnated cord along with the advantage of being a biocompatible material to be used in the surroundings of the soft tissues. Furthermore, these experimental cords were superior to nonimpregnated cords.
Further long-term clinical trials are needed to look for any effects on gingiva such as gingival recession and in cases of deep periodontal pockets. Use of knitted instead of braided cords to reduce the fraying with better packability of the chitosan cords can be carried out and to compare other gingival retraction cords to evaluate for different parameters.
| Conclusion | | |
Within the limitations of this in vivo study, it can be concluded that:
- No statistically significant difference was seen with respect to both the chitosan gingival retraction cords in all the criteria
- Both the experimental cords were superior to that of nonimpregnated cord with respect to all the criteria except for the ease of packing the cord
- The experimental chitosan cords have no significant difference with respect to ceasing the bleeding from the gingival sulcus with the further enhancement to the dry and widened sulcus when compared with aluminum chloride.
Our study concludes that both the chitosan groups are equally effective as aluminum chloride cords in hemostasis, insignificant bleeding at removal, dry sulcus, and widening of sulcus, thus making these experimental chitosan cords equivalently good.
Further long-term clinical trials are needed to look for any effects on gingiva such as gingival recession and in cases of deep periodontal pockets. Use of knitted instead of braided cords to reduce the fraying with better packability of the chitosan cords can be carried out and to compare other gingival retraction cords to evaluate for different parameters.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]
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