Journal of South Asian Association of Pediatric Dentistry
Volume 6 | Issue 2 | Year 2023

A Case Series of Resin Infiltration as Minimally Invasive Method for Treatment of Enamel Opacities

Neha Shrestha1, Sumita Upadhyay2, Rasna Shrestha3, Parayash Dallakoti4

1-4Department of Pediatric and Preventive Dentistry, Kathmandu University School of Medical Sciences (KUSMS), Dhulikhel, Nepal

Corresponding Author: Sumita Upadhyay, Department of Pediatric and Preventive Dentistry, Kathmandu University School of Medical Sciences (KUSMS), Dhulikhel, Nepal, Phone: +91 9841271000, e-mail:

Received on: 01 June 2023; Accepted on: 20 June 2023; Published on: 23 August 2023


Enamel opacities occur because of defects in the formation of the organic matrix during the development of tooth enamel. These lesions are often seen in dental practice. It is a challenge to treat such lesions with minimal invasion, while also fulfilling esthetic demands. The initiation of the resin infiltration technique has provided an intermediate therapy option in the middle of preventive and corrective therapies. The present case report aims to report the treatment of enamel lesions in the anterior teeth of the arch, with resin infiltration procedure. Formally devised for the conservative treatment of initial carious areas, resin infiltration has been popular among practitioners because of its covering effect on decalcifying enamel and an array of advancing enamel defects.

How to cite this article: Shrestha N, Upadhyay S, Shrestha R, et al. A Case Series of Resin Infiltration as Minimally Invasive Method for Treatment of Enamel Opacities. J South Asian Assoc Pediatr Dent 2023;6(1):91-94.

Source of support: Nil

Conflict of interest: Dr Sumita Upadhyay is associated as the Editorial board members of this journal and this manuscript was subjected to this journal’s standard review procedures, with this peer review handled independently of these Editorial board members and their research group.

Patient consent statement: The author(s) have obtained written informed consent from the patient’s parents/legal guardians for publication of the case report details and related images.

Keywords: Case report, Enamel opacities, Minimal invasive, Resin infiltration.


Enamel white spots are present as a result of pre/posteruptive damages. Disturbances during enamel development can cause a condition like enamel fluorosis, trauma-related hypocalcification, and molar incisor hypomineralization (MIH). The posteruptive discolorations can result from carious lesions and are called incipient caries or white spot lesions (WSL). These conditions involve altered chemical composition and optical properties.1 Local application of remineralizing agents, microabrasion,2 and bleaching,3 tries to overturn enamel demineralization and enhance tooth appearance. In young children and adolescents, conservative esthetic treatment is favorable in comparison to invasive techniques.4 The demands for conservative and esthetic treatment have introduced new remedies for enamel opacities. Microinvasive therapies, such as resin penetration, with the use of effective component triethylene glycol dimethacrylate (TEGDMA) are known for treating demineralized enamel.5 The low-thickness light curing resins used in the resin infiltration technique were created for quick diffusion into porous enamel and are used to clog the porosities within the lesion.6 The only material present in the market for the mentioned technique is icon by DMG (Hamburg, Germany). This material was originally developed for treating early caries and/or WSLs extending up to a superficial third of dentin.7 With the intention of enhancing strength and mild esthetic appearance of hypomineralized areas, this case report highlights the clinical efficacy of a minimally invasive infiltrant resin approach as a promising option for treating microporous lesions.


Case 1

A boy of 10 year old, visited the Department of Pediatric and Preventive Dentistry complaining of carious teeth in the upper and lower back teeth region at both sides of the arch. On intraoral examination, hypomineralized lesions in permanent upper and lower first molars on both sides and upper central incisors were recorded. The hypomineralized areas presented as isolated enamel opacities on the middle and incisal thirds of upper central incisors. There was a negative history of trauma, and fluorosis and a positive finding of association with similar opacities in permanent first molars. After the routine examination, the diagnosis of MIH was confirmed. The permanent first molars of all quadrants were treated as required and stainless steel crowns were placed on lower permanent first molars. There was no contributory medical history. The minimally invasive, resin infiltration technique was recommended, discussed, and performed with the approval of the patient and patient party. The teeth were first cleaned with a preventive paste and then isolated with the use of a rubber dam. The infiltration technique was performed following the manual’s guidance on upper central incisors. The sequence of icon (DMG, Hamburg, Germany), was followed, where 15% hydrochloric acid gel was applied for 120 seconds for etching purposes. Soon after the surface rinsing was done for 30 seconds, dried, and accessed to check color modification (frosty white). Then air-drying of the surfaces was done, and after that ethanol 99% was applied. Application of resin infiltrant was done on the various surfaces, and three minutes were given for it to penetrate. A blow of air was used to remove the excess followed by light curing for 40 seconds. The initial outcome was evaluated, and the application was repeated for 1 minute and cured for 40 seconds. Finally, finishing and polishing were done using polishing disks and silicone rubber to prevent rediscolorations by food colors. The opacities appeared light in color, however, complete disappearance couldn’t be achieved. The pre and post treatment results on the same day are shown in (Figs 1A and B), respectively. Nevertheless, the patient was pleased with the treatment.

Figs 1A and B: (A) Pretreatment; (B) Posttreatment

Case 2

A 9-year-old male child complained of discolored upper front teeth. After the clinical examination, the occurrence of hypomineralized enamel with respect to upper central incisors was diagnosed. The resin infiltration technique was carried out, as mentioned in case 1. Pre-treatment and post-treatment results on the same day are shown in (Figs 2A and B), respectively.

Figs 2A and B: (A) Pretreatment; (B) Posttreatment

Case 3

An 8-year-old girl reported with a chief complaint of discolored and sensitive upper front teeth. Resin infiltration was carried out on the same appointment. The patient was followed up to 5 years. No posteruptive breakdown was seen, and the parents didn’t want further esthetic restoration. The pre and posttreatment images are shown in (Figs 3A to C), respectively.

Figs 3A to C: (A) Pretreatment; (B) Posttreatment; (C) 5-year follow-up


Enamel opacities of any type, are very likely to be of concern for children and adolescents. Discolored anterior teeth can hamper their self-esteem and cause psychological and social trauma. Extensive treatment options like veneers are not recommended at this stage, as the teeth are immature. Moreover, the bonding capacity of these opacities to various restorative treatments is very low. Therefore minimally invasive treatment approaches are recommended in treating enamel opacities in incisors owing to the high pulp horns and less dentin thickness which can lead to dentinal hypersensitivity. Various approaches for treatment have been proposed, out of which microabrasion has been considered effective and conservative, but results in loss of enamel surface.8 Literature on resin infiltration has concluded effective masking effects.9 This method removes only 30–40 μm while microabrasion removes around 360 μm.10 However, the esthetic impacts of resin infiltration cannot be foreseen. Research by Robinson et al. says resin may infiltrate about 60 ± 10% of the lesion’s pore volume.11 Resin can reportedly penetrate up to a depth of over 100 μm, according to Kielbassa et al.12 The early demineralized regions have minute pores. These enamel caries lesions’ microporosities are made up of either aqueous medium [refractive index (RI) 1.33] or air (RI 1.0). Because of light scattering caused by different refractive indices among porosities and healthy enamel (RI 1.62), those areas seem opaque. The RI of resin-infiltrated microporosities is 1.46, which lowers the disparities in RI, making lesions resemble nearby healthy enamel because, unlike a watery medium, it cannot evaporate. This is the theory behind how resin infiltration works, which is based on how the lesions alter, after light scattering.6 By blocking the porosities that allow acids to flow through them, resin infiltration’s capillary action prevents the lesion’s progression in its tracks. As a result, it seeks to establish a barrier to diffusion inside the lesion as opposed to on its surface.12

Resin icon is offered in proximal as well as vestibular surface kits, respectively. Apart from the need for separation in the treatment of proximal lesions, the techniques for both are comparable. Because of the reduced pore capacity of the topmost layer of carious enamel compared to the body of the lesion below, this acts as a shield from preventing resin into the body of the lesion. Therefore, a preliminary step is necessary which involves cleaning the surface of teeth with 15% hydrochloric acid for 120 seconds, occasionally swirling the material as it is applied. When administered for 120 seconds, 15% hydrochloride gel has been demonstrated to be more efficient than 37% phosphoric acid gel at removing the mineralized top surface of the enamel. It produces penetration depths of more than double that of phosphoric acid (25 μm).10 Icon-dry, made of 99% ethanol, is applied for 30 seconds before being allowed to dry, is established on the idea that it will boost hydrophobic monomers to penetrate into demineralized humid enamel/dentine and enhance the efficacy of penetration to obtain distinct resin infiltrated layer. Icon resin made up of TEGDMA is applied for 3 minutes allowing the resin to penetrate microporosities and occlude them in order to block acid access.12-14

In the first case, drastic changes in esthetic couldn’t be achieved for which correction by veneer has been planned. The fact that the extent of opacity is not restricted to the topmost layer of enamel may be the cause of some lesions continuing even after treatment. However, the benefits achieved are an increase in microhardness of the teeth, an increase in bonding capacity to restorative materials, and a decrease in hypersensitivity.12 Despite the severity of the hypomineralization, resin infiltration is always recommended before planning permanent restoration. The second and third cases showed satisfactory esthetic results.13 The main purpose of treating lesions was to prevent further ingress of caries and to strengthen the teeth. All three patients have been given options to further improve esthetics through prostheses. The first two cases were not followed as it was a single setting procedure and results were evaluated in the same visit. The third case was followed after 5 years and found a satisfactory decrease in opacity.


According to the results of the current instances, the minimally invasive resin infiltration technique for treating enamel opacities appears to be efficient, less destructive, and more user- and time-friendly.


Parayash Dallakoti


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