SRM Journal of Research in Dental Sciences

ORIGINAL ARTICLE
Year
: 2021  |  Volume : 12  |  Issue : 4  |  Page : 192--197

Comparative evaluation of esthetic improvement of resin infiltration and resin infiltration with double infiltrant application on nonpitted fluorosis stains: A six months prospective longitudinal study


Ishika Garg 
 Department of Pedodontics and Preventive Dentistry, Post Graduate Institute of Dental Sciences, Rohtak, Haryana, India

Correspondence Address:
Dr. Ishika Garg
Department of Pedodontics and Preventive Dentistry, Post Graduate Institute of Dental Sciences, Rohtak, Haryana
India

Abstract

Background: Resin infiltration (RI) is a new noninvasive treatment modality that has gained increasing popularity in recent years for the treatment of dental fluorosis stains. Aim: The present study evaluated and compared the esthetic improvement (EI) of RI and RI with a double infiltrant application (2RI) on mild to moderate nonpitted fluorosis stains for a period of 6 months. Materials and Methods: A total of 36 patients in the age range of 6–12 years with unesthetic appearance of upper anterior teeth due to nonpitted fluorosis stains were randomly selected and divided into two groups: (i) RI group-intervention with RI (ii) 2RI group-intervention with 2RI. Standardized photographs were taken preoperatively, immediate postoperatively and after 1, 3, and 6 months' time interval postoperatively to assess for EI and changes in surface opacities/stains (SC) using a visual assessment scale (VAS). Results: Binary comparison showed statistically insignificant difference (P > 0.05) for both the evaluation parameters, EI and SC, between RI and 2RI at all the follow-up intervals. Intra-group comparisons showed a statistically significant difference (P < 0.01) for the VAS values of EI and SC between the follow-up time intervals for both the groups with the highest values at 6 months' time interval. Conclusion: For EI parameter, nearly equivalent clinical success was observed in RI and 2RI groups. For SC parameter, the best results were obtained in 2RI treatment group. RI is a promising procedure with remarkable clinical success for esthetic management of mild to moderate nonpitted fluorosis stains.



How to cite this article:
Garg I. Comparative evaluation of esthetic improvement of resin infiltration and resin infiltration with double infiltrant application on nonpitted fluorosis stains: A six months prospective longitudinal study.SRM J Res Dent Sci 2021;12:192-197


How to cite this URL:
Garg I. Comparative evaluation of esthetic improvement of resin infiltration and resin infiltration with double infiltrant application on nonpitted fluorosis stains: A six months prospective longitudinal study. SRM J Res Dent Sci [serial online] 2021 [cited 2022 Nov 26 ];12:192-197
Available from: https://www.srmjrds.in/text.asp?2021/12/4/192/332897


Full Text



 Introduction



Fluoride has a crucial role in dental caries prevention. However, chronic exposure to high intakes of fluoride during tooth development results in dental fluorosis. Nonpitted dental fluorosis causes tooth discoloration ranging from white opacities to yellow or dark brown stains and often raises esthetic concerns in children especially when it affects the permanent maxillary anterior teeth.[1] Moreover, it has been reported to have a psychological impact on the individuals especially adolescents.[2]

A number of treatment measures both invasive and/or noninvasive have been advised for esthetic management of dental fluorosis. However, minimally invasive interventions for these defects are of great importance especially in the young age groups to prevent extensive tooth destruction caused by the invasive procedures and for reducing treatment duration and cost.

In recent past, resin infiltration (RI) technique, originally recommended for arresting early caries and for esthetic management of white spot lesions,[3] has also been reported to improve fluorosis stains.[4],[5] It is a micro-invasive treatment of incipient caries limited to enamel without sacrificing healthy tooth structure. The principle of RI is to perfuse the porous enamel with resin by capillary action which blocks further diffusion pathways for the bacteria by creating barriers and stops the lesion progression. RI, with its near similar refractive index (1.46) to that of healthy enamel (1.62) creates a chameleon effect-a blend shading of the teeth lesions with the tooth surface.[6],[7]

The past studies in the literature to date have revealed good to excellent esthetic improvement (EI) with RI in mild-to-moderate dental fluorosis stains. However, to the best of our knowledge, there has been no study in the literature till now to show follow-up results with respect to double resin infiltrant application on fluorosis stains. The present study was done to evaluate and compare the EI of RI and RI with double infiltrant application (2RI) on nonpitted fluorosis stains in 6-12 year old children with a 6 months' follow-up time frame.

 Materials and Methods



Study design

It was a prospective interventional study with 6 months' follow-up commenced after obtaining ethical clearance from the Institutional Ethics Committee on 20th December 2018 with ethical approval number PGIDS/IEC/2018/23. All the participants provided written informed consent for the participation in the study. All the procedures in the study were conducted in accordance with the ethical principles postulated in Declaration of Helsinki in 1964 and revised in 2013.

Study setting

The study was conducted at the Department of Pedodontics and Preventive Dentistry, Post Graduate Institute of Dental Sciences, Rohtak in a time span of 1 year from March 2019 to March 2020.

Participants

A total of 36 healthy controls aged 6–12 years with unesthetic appearance (white or brown discoloration, stains and/or opacities) of upper anterior teeth due to nonpitted fluorosis stains seeking dental treatment were randomly recruited from the Outpatient Department of Pediatrics and Preventive Dentistry and distributed evenly into two groups:

RI Group-Intervention with RI2RI Group-Intervention with 2RI.

A written informed consent was taken from each participant before enrolling in the study. Children with nonfluoride opacities and pitted fluorosis, history of known allergy towards any dental material, systemic illness (mental retardation/severe psychotic disorders), severe sensory and/or motor impairment, and those unwilling for participation were excluded from the study.

One of the diagnostic criteria taken in our study was that dental fluorosis in permanent dentition usually presents bilateral involvement of teeth. The explanation lies in the fact that the affected areas on corresponding pairs of teeth (e.g., left/right central incisors, lateral incisors) were all at the same point of enamel formation when the exposure to the fluoride took place. The “fluoride” and “nonfluoride” opacities were differentiated following Russell's criteria, according to which all symmetrically distributed and nondiscrete opaque conditions of enamel are fluorosis.[8] Moreover, most of the patients' history of being the resident of an area that is rich in fluoride in water supply combined with the dental expert's clinical judgment led to the diagnosis of fluorosis stains for the participants included in the study. The classification of severity of dental fluorosis was done using Dean's Fluorosis Index (DFI)–Modified Criteria (1942).[9] The participants with DFI score of 0.5, 1, 2, 3 that is nonpitted fluorosis were incorporated in the study. Since fluorosis generally affects more than one tooth in the dentition, in such cases the anterior tooth most severely affected due to fluorosis and presenting maximum DFI score were considered.

Study size

As per 80% power analysis, 14 patients were needed in each group with an expected mean difference of 1.3 and accepted alpha error of 5%. For estimated dropout, 4 subjects per samples were added for each group (25% dropouts). Henceforth, a total of 18 subjects per group were included.

Prior to the beginning of treatment procedure, all the participants underwent supervised teeth brushing. Subsequently, a standardized preoperative photograph was carried out.

Clinical procedure

RI group: Intervention with resin infiltration

The procedure was carried out using RI kit as per the manufacturer's instructions using the commercially available RI kit (ICON [DMG, Germany]). The ICON kit comprises of 3 syringes, that is, 15% hydrochloric acid gel (ICON Etch), ethanol-drying agent (ICON Dry), and resin infiltrant (ICON Infiltrant). The procedure consisted of the placement of rubber dam to obtain a clean working field free of saliva [Figure 1]a. In the first step, the application of 15% HCl gel was done for 2 min with the applicator tip and stirred with a micro brush to achieve a uniform “etchy” pattern [Figure 1]b. Thereafter, the etching gel was rinsed away with water for 30 s [Figure 1]c. In the second step, 99% ethanol was applied to desiccate the enamel lesion and remove the water retained in the microporosities of enamel [Figure 1]d. This was followed by air drying of the tooth surface [Figure 1]e. In the last step, low viscosity resin infiltrant was applied and allowed to rest for 3 min on the tooth surface to enable it to penetrate deeply into the lesion [Figure 1]f. After 3 min, the excess resin on the tooth surface was removed with a piece of cotton. The resin was then light-cured for 40 s [Figure 1]g and [Figure 1]h. Moreover, a second layer of infiltrant was applied [Figure 2]a and cured for additional 1 min [Figure 2]b and [Figure 2]c. This was followed by polishing the enamel surface with pumice [Figure 2]d and [Figure 2]e.{Figure 1}{Figure 2}

Resin infiltration with double infiltrant application group: Intervention with resin infiltration with double infiltrant application

The intended tooth was again subjected to RI procedure as in Group I. In addition, one more layer of infiltrant application was done for 3 min and subjected to light cure polymerization for 40 s [Figure 2]f and [Figure 2]g.

Follow-up of the study participants

In all the participants, standardized photographs were taken by the operator preoperatively, immediate postoperatively and after 1, 3, and 6 months' time interval using Canon IXUS 185 digital camera in fixed light conditions from a set distance [Figure 3]. All photographs were stored in a computer and evaluated later for EI and changes in SC by two independent observers using a visual assessment scale (VAS) from 1 to 7 (1, 2 = No improvement; 3 = Mild improvement; 4, 5 = Moderate improvement; 6, 7 = Exceptional improvement). To ensure blinding of the outcome evaluators, the evaluators were not disclosed about the participant's treatment group. Cohen's kappa statistics for inter-examiner reliability was calculated to be 0.78 indicating substantial agreement.{Figure 3}

Statistical analysis

The data collected was entered into Microsoft Office Excel to prepare a master chart and put through statistical analysis using the Statistical Package for Social Sciences(SPSS v 21.0, IBM Corporation, SPSS Inc., Chicago, IL, USA). Pair-wise comparison between the two groups for both the evaluation parameters (EI and SC) was done using post hoc Tukey's test. Intra-group comparison was done using repeated measures ANOVA test. Moreover, unpaired student t-test was used for inter-grade comparison of fluorosis in both the groups for both EI and SC. For all the statistical tests, P ≤ 0.05 was considered to be statistically significant.

 Results



The total number of patients included in the study was 72 in the age group of 6–12 years with the mean age of 11.36 years. Random allocation of the study subjects who fulfilled the inclusion criteria was done and it was found that the number of males and females were equally distributed. At 6 months follow-up, 3 subjects dropped out in RI group and 4 subjects dropped out in 2RI group. Hence, the final number of study subjects was 29.

Intra-group comparison of EI and changes in SC over follow-up time intervals showed a highly significant difference statistically (P < 0.01) for the values of EI and SC between the follow-up time intervals for both RI and 2RI groups with highest values at time interval 6 months followed by 3 months, 1 month and least at immediate postoperative (P = 0.001) [Table 1].{Table 1}

Pair-wise comparison of mean EI and SC at all the follow-up intervals using post hoc Tukey's test showed that there was a statistically insignificant difference (P > 0.05) for the mean VAS score values for EI and SC [Table 2] between RI group and 2RI group.{Table 2}

Inter-grade comparison of fluorosis revealed a highly significant difference statistically (P < 0.01) for the VAS scores between the grades of fluorosis after RI and 2RI treatment with the highest mean VAS score values in very mild degree of fluorosis followed by mild and moderate degrees for both EI and SC [Table 3].{Table 3}

 Discussion



Clinical management of tooth discoloration due to dental fluorosis intends to produce acceptable and esthetically stable results as conservatively as possible. RI is a newer micro-invasive technique that has reportedly produced successful esthetic results in the management of mild to moderate fluorosis stains as per various studies.[7],[10],[11] The technique is based on the erosion of the lesion surface with hydrochloric acid followed by penetration of low-viscosity resin into the inter-crystalline spaces of demineralized enamel. The infiltrated resinous material with its near similar refractive index to that of hydroxyapaptite alters the refractive index of porous enamel previously filled with air or water. Consecutively, the optical characteristics of the affected enamel are changed and it seems like the surrounding healthy enamel.[12]

The highest VAS score values at 6 months period in RI group for both EI and SC were in agreement with the studies conducted by Auschill et al.,[7] Cocco et al.,[11] Owda and Sancakli[13] and Garg and Chavda[14] who have reported long-term positive outcomes of RI. White/brown opacities/stains caused due to fluorosis are thought to mimic white spot demineralization, as histologically fluorosis is also a deep-seated hypomineralized porous defect covered by a thick surface layer.[15] The improvement in esthetics by RI could be attributed to blending of enamel lesions with the surrounding sound enamel, based on changes in the refractive index.[16] Similar results obtained in 2RI group were in accordance with the randomized controlled trial conducted by Gugnani et al. who reported that additional infiltrant application time may have contributed to the deeper penetration of resin in the hypomineralized areas of fluorosis resulting in superior esthetic results and improvement in stains, due to the similarity in the refractive index of the infiltrant and sound tooth zones.[6]

In the present study, the mean EI and SC scores for RI group was 5.40 ± 0.632 and 5.27 ± 0.799 respectively, and for 2RI group, 5.14 ± 0.949 and 5.79 ± 0.579, respectively. These findings were similar to the randomized controlled trial conducted by Gugnani et al. who demonstrated the mean EI and SC scores for RI group to be 5.50 ± 1.00 and 4.98 ± 0.98 respectively, and for 2RI group, 5.53 ± 1.97 and 5.18 ± 1.29, respectively.[6]

Lesser the degree of fluorosis, less porous is the enamel surface and better is the penetration of resin. Hence, the esthetic results were improved in milder degrees of fluorosis as compared to severe stains. This difference could be attributed to the volume and depth of the subsurface pores that increase as the severity of dental fluorosis rises.[17]

The follow-up period of the study was 6 months. Longer follow-up spans are necessary to evaluate the sustainability of the results based upon which the time of re-application. Moreover, more studies with both subjective and objective parameters are required to ensure high predictability of the treatment outcomes.

 Conclusion



In the present study, both RI and 2RI groups demonstrated nearly equivalent clinical success for both the evaluation parameters, EI and changes in SC, in mild to moderate nonpitted fluorosis stains with a long-lasting positive outcome (up to six months). However, slightly better clinical results were noticed in 2RI group for changes in surface opacities/stains in nonpitted fluorosis. Based upon the study results, the author of this study recommends double RI as one of the best noninvasive treatment modality for esthetic management of mild to moderate nonpitted fluorosis stains.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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