Comparison of the efficacy of Icon resin infiltration and Clinpro XT varnish on remineralization of white spot lesions: An in-vitro study Edunoori R, Dasari AK, Chagam MR, Velpula DR, Kakuloor JS, Renuka G

ORIGINAL ARTICLE

Year : 2022 | Volume : 11 | Issue : 1 | Page : 12

Comparison of the efficacy of Icon resin infiltration and Clinpro XT varnish on remineralization of white spot lesions: An in-vitro study

Ratnavally Edunoori, Arun K Dasari, Manjunatha R Chagam, Deepti R Velpula, Jeevan S Kakuloor, Gajji Renuka
Department of Orthodontics, SVS Institute of Dental Sciences, Mahabubnagar, Telangana, India

Date of Submission	12-May-2021
Date of Decision	05-Jun-2021
Date of Acceptance	25-Nov-2021
Date of Web Publication	04-May-2022

Correspondence Address:
Arun K Dasari
Department of Orthodontics, SVS Institute of Dental Sciences, Mahabubnagar - 509 002, Telangana
India

Source of Support: None, Conflict of Interest: None

Check

DOI: 10.4103/jos.jos_141_21

Abstract

OBJECTIVE: To compare the efficacy of Icon resin infiltration and Clinpro XT varnish on remineralization of white spot lesions using a polarized light microscope (PLM).
MATERIALS & METHODS: Artificial white spot lesions were created on a sample of 40 extracted human premolar teeth by immersing in a demineralizing solution. All samples were randomly allocated to two groups of 20 each; Group A: Icon resin infiltration and Group B: Clinpro XT varnish. Teeth were sectioned along the buccolingual plane using a diamond disc. Specimens were observed under the PLM (4× magnification) at three deepest measurements and their averages were calculated to obtain the mean penetration depth. The data obtained were analyzed using SPSS software (version 22.0). Independent samples t-test and group statistics were used to compare the two groups. In all statistical tests, the significance level was set at 5% (P < 0.05).
RESULTS: Both Icon resin infiltration and Clinpro XT groups showed a statistically significant difference (P = 0.00) in the penetration depth. Icon resin infiltration group showed a significantly higher penetration depth (24.46 μm) compared to the Clinpro XT group (12.34 μm). Group A showed a greater mean penetration depth (17.07 ± 4.35 μm) when compared to group B (7.68 ± 1.81 μm).
CONCLUSION: Icon resin infiltration showed a significantly higher penetration depth and is more effective on remineralization of white spot lesions when compared to Clinpro XT varnish.

Keywords: Clinpro XT varnish, icon resin infiltration, polarized light microscope, resin penetration depth, white spot lesions

How to cite this article:
Edunoori R, Dasari AK, Chagam MR, Velpula DR, Kakuloor JS, Renuka G. Comparison of the efficacy of Icon resin infiltration and Clinpro XT varnish on remineralization of white spot lesions: An in-vitro study. J Orthodont Sci 2022;11:12

How to cite this URL:
Edunoori R, Dasari AK, Chagam MR, Velpula DR, Kakuloor JS, Renuka G. Comparison of the efficacy of Icon resin infiltration and Clinpro XT varnish on remineralization of white spot lesions: An in-vitro study. J Orthodont Sci [serial online] 2022 [cited 2023 Oct 2];11:12. Available from: https://www.jorthodsci.org/text.asp?2022/11/1/12/344718

Introduction

Every orthodontic patient wants to have a beautiful smile and aesthetics after fixed orthodontic treatment. White spot lesions (WSLs), an early sign of demineralization, is one of the most common adverse effects of orthodontic treatment, which will detract from the smile even with a well-balanced face and occlusion. Nearly 50% of patients undergoing fixed orthodontic treatment exhibit clinically visible WSLs due to poor oral hygiene maintenance, which turns the smooth tooth surfaces into retentive sites for plaque accumulation.^[1],[2],[3] Areas that were once self-cleansing due to salivary flow and oral musculature become stagnant, plaque-collecting zones.^[4] Bacteria release lactic acid, which decreases the plaque pH adjacent to orthodontic brackets leading to demineralization or decalcification of the enamel.^[2],[5],[6]

Subsurface mineral loss causes the normal translucent enamel to become opaque due to an optical phenomenon producing WSLs.^[7],[8] These lesions appear in just 4 weeks around the brackets, especially in the gingival region.^[2],[3],[6] WSL is a major challenge during and after fixed orthodontic treatment as it leads to caries development. WSLs can be managed by various methods such as fluoride-releasing materials in the form of toothpaste, gels, varnishes, mouth rinses;^{[9],[10],[11],[12],[13]} casein derivatives such as casein phosphopeptide amorphous calcium phosphate (CPP-ACP) complexes;^[14],[15] bioactive glass;^[16] laser therapy;^[17] silver nanoparticles;^[18],[19] ozone therapy;^[20] bleaching, and microabrasion.^{[21],[22],[23]} However, these methods are very effective in preventing WSLs by remineralizing the superficial surface of the lesion and not the entire depth of the lesion.

Various methods available to assess the demineralization on the surface and sub-surface enamel are quantitative light-induced fluorescence (QLF), X-ray micro-tomography (XRMT), optical coherence tomography (OCT), confocal laser scanning microscope (CLSM), polarized light microscope (PLM), etc.^[24] However, PLM was considered as the best method that can give a high degree of differentiation between demineralized area and normal area of the tooth along with entire lesion depth measurements.

There is no golden standard for the treatment of WSLs. As WSL is a form of demineralization, remineralization is the most conservative method to be tried primarily. More recently, a minimally invasive treatment approach was introduced, where the WSL is infiltrated using a low-viscosity resin (Icon-DMG).^[25] Also, a resin-modified glass ionomer cement (Clinpro XT varnish) is introduced to the market and is supposed to be most beneficial in remineralizing WSLs; however, it is yet to be proved in orthodontic setup. Therefore, the present study was undertaken to compare the efficacy of Icon resin infiltration and Clinpro XT varnish on remineralization of WSLs using PLM.

Materials and Methods

Sample collection

A sample of 40 freshly extracted human premolar teeth was stored in 0.1% thymol solution to prevent dehydration and bacterial growth. Inclusion criteria were: 1) atraumatically extracted premolar teeth for orthodontic purposes, 2) teeth with sound noncarious premolars, and 3) teeth with no visible enamel defects.

Preparation of samples for white spot lesions

Artificial WSLs were created on the buccal surface of each tooth by immersing and storing them in a demineralizing solution (2.2 mM calcium chloride, 2.2 mM monopotassium phosphate, 0.05 mM acetic acid with pH adjusted to 4.4 and 1 M potassium hydroxide) for 96 h. All the teeth (n = 40) were thoroughly washed with distilled water, air dried, and then the samples were randomly allocated to two groups of 20 each. Group A: Icon Resin Infiltration (Icon DMG America, Englewood, NJ, USA) and Group B: Clinpro XT varnish (3M ESPE, Pymble, New South Wales, Australia).

Specimen preparation

Each tooth was cleaned with non-fluoridated pumice using a rubber prophylactic cup on a slow-speed handpiece and each sample was thoroughly dried for 20 s.

Group A (Icon Resin Infiltration): The buccal surface of each tooth created with WSLs was etched with 15% hydrochloric acid gel (Icon-Etch, DMG) for 2 min, rinsed with water, and dried with moisture-free air for 30 s. Ethanol 99% (Icon-Dry, DMG) was applied for 30 s and air-dried. Resin Infiltrant (Icon-Infiltrant, DMG) was applied and left for 3 min, followed by light curing for 40 s. A second coat of Icon-Infiltrant (DMG) was applied, left for 1 min, and light-cured for 40 s.

Group B (Clinpro XT varnish): The buccal surface of each tooth created with WSLs was etched with 37% phosphoric acid for 30 s, rinsed with water, and air-dried for 3 s. Then, a thin layer of Clinpro XT varnish was applied and light-cured for 20 s.

The penetration depth of the materials into the lesions was determined by immersing the specimens in 10% methylene blue dye for 24 h at 37°C in an incubator. The teeth were washed with distilled water for 60 s and allowed to dry, after which specimens are sectioned along the buccolingual plane with a diamond disc mounted on a low-speed handpiece [Figure 1]. Subsequently, specimens were observed under the PLM at 4× magnification for determining the depth of penetration of the materials in micrometers (μm). PLM photomicrographs showing the penetration depth of Icon resin infiltration [Figure 2] and Clinpro XT varnish [Figure 3] suggested that the demineralized lesion appeared darkened and the infiltrated material appeared blue in color. To achieve reproducible measurements, three deepest measurements (μm) for infiltrant depth were taken for each section and their averages were calculated as the mean of maximum penetration depth.

Figure 1: Sectioned Group A and Group B specimens

Click here to view

Figure 2: Polarized light microscope photomicrograph showing penetration depth of Icon resin infiltration at three different locations

Click here to view

Figure 3: Polarized light microscope photomicrograph showing penetration depth of Clinpro XT varnish at three different locations

Click here to view

Statistical analysis

The data obtained were analyzed using the SPSS software, version 22.0 (SPSS Inc., Chicago, IL, USA). Descriptive statistics were calculated for both the groups including mean values, standard deviations, minimum, and maximum values. Independent samples t-test and group statistics were used to compare the two groups. In all statistical tests, the significance level was set at 5% (P < 0.05).

Results

The penetration depth was determined by measuring the width of remineralization at three different areas in a lesion and the average value was considered as the mean penetration depth of the materials into the lesion. In Group A sample, the mean penetration depth in the first, second, and third areas were 19.70 μm, 14.19 μm, and 17.32 μm respectively, whereas in the Group B sample, the mean penetration depth in the first, second, and third areas were 7.92 μm, 7.63 μm, and 7.49 μm, respectively [Table 1].

Table 1: Mean values (μm), standard deviation, and corresponding statistics of linear measurements of penetration depths among the groups

Click here to view

When comparing the two groups, with penetration depth as a dependent variable, it showed a significant difference in penetration depth between the two groups at a 5% level of significance. The Icon group showed a significantly higher penetration depth (24.46 μm) when compared to the Clinpro XT group (12.34 μm) [Table 2].

Table 2: Comparison between two study groups with penetration depth as a dependent variable

Click here to view

An independent sample t-test was used to compare the mean penetration depth values between the two groups showed a statistically highly significant difference in the penetration depth. The Icon group showed a greater mean penetration depth (17.07 ± 4.35 μm) when compared to the Clinpro XT group (7.68 ± 1.81 μm), which indicated that the Icon group had greater infiltrative and remineralizing capacity when applied to demineralized enamel [Table 3].

Table 3: Independent samples t-test to compare mean penetration values between the groups

Click here to view

Discussion

Fixed orthodontic appliances limit the naturally occurring self-cleansing mechanisms of the oral musculature and saliva leading to increased plaque retention and subsequent WSL formation.^[26] During orthodontic treatment, those patients with poor oral hygiene maintenance, without fluoride supplementation, and with high Streptococcus mutans count are more susceptible to enamel demineralization and WSL formation.^[3],[7],[27]

Depending on a patient's risk factors, a number of suitable agents and therapies can be used to prevent WSLs in orthodontic patients. WSL treatment should start with the most conservative procedure and then progress to more invasive methods as needed.^[28] In recent years, microinvasive or minimum intervention dentistry has evolved and its aim is “maximum conservation of demineralized, non-cavitated enamel and dentin.”^[29] A caries infiltrant resin (Icon) recommends the microinvasive approach by treating WSLs in one office visit without patient compliance and restores the natural appearance of the teeth. Shah et al.^[30] suggested that a single application of Clinpro-XT prevents enamel demineralization for up to 120 days, whereas conventional fluoride varnish prevents the same for 45 days during fixed appliance therapy. To date, there are no such in vitro studies that have directly or indirectly compared the effect of Icon resin infiltration and resin-modified glass ionomer Clinpro XT varnish on remineralization of artificially created WSLs.

In the present study, it was observed that the Icon resin infiltration and Clinpro XT varnish certainly have the ability to penetrate enamel affected by artificial WSL. Both the groups, i.e., Icon resin infiltration and Clinpro XT varnish had a mean penetration depth of 17.07 ± 4.35 μm and 7.68 ± 1.81 μm, respectively. The penetration depth of Icon resin infiltration was significantly greater than the penetration depth of Clinpro XT varnish. This is in concordance with the study conducted by Arora et al.^[31] who concluded that the Icon resin infiltrant had the highest depth of penetration and microhardness followed by Embrace and Clinpro.

In the Icon resin infiltration group, the maximum penetration depth values obtained were 24.46 μm, which is in support of a study conducted by Zankalouny et al.^[32] The penetration depth values obtained in our study were lower than those obtained in the study conducted by Meyer-Lueckel et al.^[33],[34] and values obtained were higher than those in the study conducted by Subramaniam et al.^[35] So, the Icon resin infiltration is more effective and has a greater depth of remineralization of the lesion.

In Clinpro XT group, the maximum penetration depth value obtained was 12.34 μm. Basdra et al.^[36] stated that the initial burst effect upon fluoride release would be more effective in preventing enamel demineralization. Contradicting this Linton et al.^[37] documented that rather than a high dose of fluoride. i.e., almost 225 ppm, a small dose of 50 ppm was more effective and stated that a high concentration of fluoride blocked the surface layer by preventing the penetration of calcium ions to the subsurface layer. It seems that high doses of fluoride are useful in inhibiting lesion formation and low doses are effective in remineralization and controlling the progression of lesions.^[9],[11]

Caries infiltration procedure was continued to refine by examining the influence of the penetration coefficient, infiltrant composition, and application time on the penetration depth and prevention of further demineralization. Studies showed that resins with a higher penetration coefficient and longer application time allowed better penetration, but these investigations only involved a shallow carious lesion that did not require much infiltration.^{[28],[38],[39]} In our study, the Icon resin infiltration successfully penetrated the artificially created WSL and formed a homogenous resin layer compared to the Clinpro XT group. The possible reasons for this could be 1) Icon resin infiltrant composition has a high content of triethylene glycol dimethacrylate (TEGDMA), a low viscosity monomer, low molecular weight, low contact angles to the enamel, and high surface tension. These properties confer a great potential for penetration and some porous areas were observed due to high ethanol content, which also helps raise the penetration coefficient. 2) In the Icon group, acid conditioning with 15% hydrochloric acid for 2 min has led to deeper resin penetration than with 37% phosphoric acid gel as in the Clinpro XT group.^[33],[40]

Conclusion

The conclusions drawn from the present study were as follows:

Resins used in both the groups, Group A (Icon Resin Infiltration) and Group B (Clinpro XT varnish) were effective in preventing or reducing the area of demineralization.
Group A showed significantly higher penetration depth compared to Group B.
Icon resin infiltration group is more effective on remineralization of artificially created WSLs compared to Clinpro XT varnish group.

Abbreviations

WSLs: white spot lesions

PLM: polarized light microscope.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest

References

1.	Gorton J, Featherstone JD. In vivo inhibition of demineralization around orthodontic brackets. Am J Orthod Dentofacial Orthop 2003;123:10-4.
2.	Gorelick L, Geiger AM, Gwinnett AJ. Incidence of white spot formation after bonding and banding. Am J Orthod 1982;81:93-8.
3.	Ogaard B, Rølla G, Arends J. Orthodontic appliances and enamel demineralization Part 1. Lesion development. Am J Orthod Dentofacial Orthop 1988;94:68-73.
4.	Chang HS, Walsh LJ, Freer TJ. Enamel demineralization during orthodontic treatment. Aetiology and prevention. Aust Dent J 1997;42:322-7.
5.	Boyd RL. Enhancing the value of orthodontic treatment: Incorporating effective preventive dentistry into treatment. Am J Orthod Dentofacial Orthop 2000;117:601-3.
6.	O'Reilly MM, Featherstone JD. Demineralization and remineralization around orthodontic appliances. An in vivo study. Am J Orthod Dentofacial Orthop 1987;92:33-40.
7.	Øgaard B. Prevalence of white spot lesions in 19-years-olds: A study on untreated and orthodontically treated persons 5 years after treatment. Am J Orthod Dentofacial Orthop 1989;96:423-27.
8.	Øgaard B. White spot lesions during orthodontic treatment: Mechanisms and fluoride preventive aspects. Semin Orthod 2008;14:183-93.
9.	Nascimento PL, Fernandes MT, Figueiredo FE, Faria-e-Silva AL. Fluoride releasing materials to prevent white spot lesions around orthodontic brackets: A systematic review. Braz Dent J 2016;27:101-7.
10.	Kau CH, Wang J, Palombini A, Abou-Kheir N, Christou T. Effect of fluoride dentifrices on white spot lesions during orthodontic treatment: A randomized trial. Angle Orthod 2019;89:365-71.
11.	Schmit JL, Staley RN, Wefel JS, Kanellis M, Jakobsen JR, Keenan PJ. Effect of fluoride varnish on demineralization adjacent to brackets bonded with RMGI cement. Am J Orthod Dentofacial Orthop 2002;122:125-34.
12.	Benson PE, Shah AA, Millett DT, Dyer F, Parkin N, Vine RS. Fluorides, orthodontics and demineralization: A systematic review. J Orthod 2005;32:102-14.
13.	Hamdan WA, Badri S, El Sayed A. The effect of fluoride varnish in preventing enamel demineralization around and under orthodontic bracket. Int Orthod 2018;16:1-11.
14.	Lopatiene K, Borisovaite M, Lapenaite E. Prevention and treatment of white spot lesions during and after treatment with fixed orthodontic appliances: A systematic literature review. J Oral Maxillofac Res 2016;7:e1.
15.	Bröchner A, Christensen C, Kristensen B, Tranæus S, Karlsson L, Sonnesen L, et al. Treatment of post-orthodontic white spot lesions with casein phosphopeptide-stabilised amorphous calcium phosphate. Clin Oral Investig 2011;15:369-73.
16.	Nam HJ, Kim YM, Kwon YH, Yoo KH, Yoon SY, Kim IR, et al. Fluorinated bioactive glass nanoparticles: Enamel demineralization prevention and antibacterial effect of orthodontic bonding resin. Materials 2019;12:1813. doi: 10.3390/ma12111813.
17.	Hsu CY, Jordan TH, Dederich DN, Wefel JS. Effects of low-energy CO2 laser irradiation and the organic matrix on inhibition of enamel demineralization. J Dent Res 2000;79:1725-30.
18.	Borzabadi-Farahani A, Borzabadi E, Lynch E. Nanoparticles in orthodontics, a review of antimicrobial and anti-caries applications. Acta Odontol Scand 2014;72:413-7.
19.	Jasso-Ruiz I, Velazquez-Enriquez U, Scougall-Vilchis RJ, Morales-Luckie RA, Sawada T, Yamaguchi R. Silver nanoparticles in orthodontics, a new alternative in bacterial inhibition: In vitro study. Prog Orthod 2020;21:24.
20.	Kronenberg O, Lussi A, Ruf S. Preventive effect of ozone on the development of white spot lesions during multibracket appliance therapy. Angle Orthod 2009;79:64-9.
21.	Murphy TC, Willmot DR, Rodd HD. Management of post orthodontic demineralized white lesions with microabrasion: A quantitative assessment. Am J Orthod Dentofacial Orthop 2007;131:27-33.
22.	Sonesson M, Bergstrand F, Gizani S, Twetman S. Management of post orthodontic white spot lesions: An updated systematic review. Eur J Orthod. 2016;39:116-21.
23.	Yetkiner E, Wegehaupt F, Wiegand A, Attin R, Attin T. Colour improvement and stability of white spot lesions following infiltration, micro-abrasion, or fluoride treatments in vitro. Eur J Orthod 2014;36:595-602.
24.	Maia AM, de Freitas AZ, de L. Campello S, Gomes AS, Karlsson L. Evaluation of dental enamel caries assessment using quantitative light induced fluorescence and optical coherence tomography. J Biophotonics 2016;9:596-602.
25.	Paris S, Meyer-Lueckel H, Cölfen H, Kielbassa AM. Penetration coefficients of commercially available and experimental composites intended to infiltrate enamel carious lesions. Dent Mater 2007;23:742-8.
26.	Guzmán-Armstrong S, Chalmers J, Warren JJ. White spot lesions: Prevention and treatment. Am J Orthod Dentofacial Orthop 2010;138:690-6.
27.	Zachrisson BU, Zachrisson S. Caries incidence and oral hygiene during orthodontic treatment. Scand J Dent Res 1971;79:394-401.
28.	Bishara SE, Ostby AW. White spot lesions: Formation, prevention, and treatment. Semin Orthod 2008;14:174-82.
29.	Murdoch-Kinch CA, McLean ME. Minimally invasive dentistry. J Am Dent Assoc 2003;134:87-95.
30.	Shah M, Paramshivam G, Mehta A, Singh S, Chugh A, Prashar A, et al. Comparative assessment of conventional and light-curable fluoride varnish in the prevention of enamel demineralization during fixed appliance therapy: A split-mouth randomized controlled trial. Eur J Orthod 2018;40:132-9.
31.	Arora TC, Arora D, Tripathi AM, Yadav G, Saha S, Dhinsa K. An In-Vitro evaluation of resin infiltration system and conventional pit and fissure sealant on enamel properties in white spot lesions. J Indian Soc Pedod Prev Dent 2019;37:133-9. [PUBMED] [Full text]
32.	El-Zankalouny SM, El Fattah WMA, El-Shabrawy SM. Penetration depth and enamel microhardness of resin infiltrant and traditional techniques for treatment of artificial enamel lesions. Alexandria Dent J 2016;41:20-5.
33.	Meyer-Lueckel H, Paris S, Kielbassa AM. Surface layer erosion of natural caries lesions with phosphoric and hydrochloric acid gels in preparation for resin infiltration. Caries Res 2007;41:223-30.
34.	Meyer-Lueckel H, Chatzidakis A, Naumann M, Dörfer CE, Paris S. Influence of application time on penetration of an infiltrant into natural enamel caries. J Dent 2011;39:465-9.
35.	Subramaniam P, GirishBabu KL, Lakhotia D. Evaluation of penetration depth of a commercially available resin infiltrate into artificially created enamel lesions: An In vitro study. J Conserv Dent 2014;17:146-9. [PUBMED] [Full text]
36.	Basdra EK, Komposh G. Fluoride released from Orthodontic bonding agents alters the enamel surface and inhibits enamel demineralization in-vitro. Am J Orthod Dentofacial Orthop 1996;109:446-72.
37.	Linton JL. Quantitive measurements of remineralization of incipient caries. Am J Orthod Dentofacial Orthop 1996;110:590-7.
38.	Meyer-Lueckel H, Paris S. Progression of artificial enamel caries lesions after infiltration with experimental light curing resins. Caries Res 2008;42:117-24.
39.	Al-Khateeb S, Exterkate R, Angmar-Mansson B, Ten Cate JM. Effect of acid-etching on remineralization of enamel white spot lesions. Acta Odontol Scand 2000;58:31-6.
40.	Gugnani N, Pandit IK, Gupta M, Josan R. Caries infiltration of noncavitated white spot lesions: A novel approach for immediate esthetic improvement. Contemp Clin Dent 2012;3:S199-202.