Effect of Resin Infiltrant and Fluoride Varnish on the Microhardness of Artificially Induced Enamel Lesion: An In Vitro Study

Abstract

Objectives

This study aims to assess the effects of resin infiltrant in comparison to fluoride varnish on the microhardness of artificially induced enamel lesions at various storage time intervals.

Materials and Methods

In this study, 36 tooth samples were assigned to two groups (n = 18): resin infiltrant and fluoride varnish. The groups were further subdivided into three distinct subgroups (n = 6) based on the storage time in artificial saliva (1-week, 2-week, and 4-week). All samples were subjected to the pH cycling procedure to induce the formation of white spot lesions. The first group received resin infiltrant treatment, while the second group was treated with fluoride varnish. Microhardness assessments were performed at the baseline, subsequent to the pH cycling procedure, and following 1-week, 2-week, and 4-week intervals from the initial application of treatment agents.

Statistical Analysis

Statistical analysis was performed using the paired t-test to evaluate within-group differences across the three time points for each material. Subsequently, an independent t-test was employed to assess between-group differences following treatment.

Results

Statistical analysis of mean microhardness values following the pH cycling procedure revealed a significant reduction in enamel microhardness in both groups (p = 0.001). Although no significant differences were observed between the two materials during the first two time intervals, a significant difference was detected in the third interval.

Conclusion

Both infiltrant and fluoride varnish enhanced enamel microhardness, with resin infiltrant demonstrating a more sustained effect over time.

 

Scroll to top

Keywords

resin infiltrant - fluoride varnish - microhardness - white spot lesions - minimally invasive dentistry

Introduction

Dental caries is one of the most common chronic diseases globally, affecting individuals of all ages and constituting a significant public health issue due to its high rates of occurrence and its profound impacts on individuals and society.[1] [2] White spot lesions represent the initial clinical manifestation of dental caries, characterized by the initial demineralization of enamel in both the surface and subsurface layers. This condition arises from plaque accumulation in areas prone to stagnation, particularly in individuals with inadequate oral hygiene. If demineralization activity is not stopped, it can progress to cavitation, which, if left untreated, may result in premature loss of primary teeth, which can compromise arch integrity by causing space loss for the eruption of cuspids and bicuspids and, ultimately, the onset of malocclusion. In permanent teeth, the caries can advance to the pulp, causing pain and infection. In advanced stages, dental caries may require more invasive procedures such as root canal treatment or extraction.[3] [4] [5] White spot lesions, also known as initial caries, early enamel caries, or smooth surface caries, exhibit an opaque white appearance due to the mineral's loss in the subsurface enamel and altered light reflection as compared with intact enamel.[6] According to Puleio et al,[7] white spot lesions occur in approximately 46% of individuals with fixed orthodontic devices, primarily resulting from plaque retention around the orthodontic brackets and bands.

Recently, noninvasive remineralization strategies have been employed to halt the progression of caries and render the lesion inactive. For decades, fluoride has served as a fundamental element in the enamel remineralization process. It is widely recognized for its caries-preventive properties, as it halts demineralization at the enamel surface and facilitates the formation of fluorapatite. Fluorapatite exhibits lower solubility than hydroxyapatite, enhancing the enamel's resistance to acid assault.[8] Furthermore, fluoride acts as a mineral reservoir, providing buffering action and serving as a protective barrier that limits acid contact with the underlying enamel.[9] Topical fluoride treatment, in different formulations, is considered an effective strategy for halting the progression of carious lesions, supporting its role in preventive dentistry.[10]

Resin infiltration is an innovative material in minimally invasive dentistry that effectively bridges the gap between preventive and restorative treatments for carious lesions that reach the first third of dentin. It is commonly used to treat discolored enamel resulting from demineralization or developmental defects in enamel. It serves as a therapeutic approach for incipient carious lesions on both the proximal and smooth surfaces of primary and permanent teeth. The main features of resin infiltration include its noninvasive nature, preservation of tooth structure, and the ability to be completed in a single visit. It halts the advancement of demineralized lesions by sealing the pores and masking the lesions, limiting future bacterial penetration.[11] In relation to the impact of resin infiltration and fluoride varnish on the microhardness of white spot lesions across different storage time intervals, no Iraqi study had been identified. Therefore, the objective of the current study is to assess the effect of resin infiltrant on the microhardness of white spot lesions across different storage time intervals in artificial saliva in comparison to the fluoride varnish.

 

Scroll to top

Materials and Methods

Sample Size Determination

Sample size calculation was performed using G*Power version 3.0.10, as described by Faul et al.[12] The parameters included a statistical power of 85%, a significance level of 0.05, and an effect size (F) of 0.25. According to Cohen's conventional classification, this effect size corresponds to a medium effect.[13] Based on these inputs, the required total sample size was calculated to be 36 teeth (6 teeth per group per time interval).

 

Scroll to top

Sample

The present study utilized 36 intact, caries-free premolar teeth that were extracted for orthodontic purposes, excluding those with cracks, restorations, or any other defects. The extractions were performed with care to minimize trauma, and the teeth were subsequently rinsed with deionized water and wiped with acetone to remove any debris. After that, the teeth were polished with rubber cups using nonfluoridated pumice and a conventional low-speed handpiece. Each tooth was then inspected under the magnifying lens to ensure there were no fractures or cracks. The samples were kept in 20 mL of deionized water containing 0.1% thymol at room temperature until use. This solution helped prevent bacterial and fungal growth while minimizing enamel brittleness.[14] [15]

 

Scroll to top

Sample Preparation

A 6-mm diameter circular window was standardized on the buccal side of the samples using an orthodontic ruler. To identify the middle area of the buccal surface, two imaginary lines were drawn: the first line extending from the tip of the buccal cusp to the cervical line and the other line connecting the mesial to the distal surface of the tooth at the most pronounced curvature of these teeth. Following that, a circular adhesive tape measuring 6 mm was cut and affixed to the sample buccal surface. The samples were then coated with an acid-resistant nail polish. Afterward, the adhesive tape was removed, creating a circular window on the buccal surface of each sample. Grit paper (400) was positioned within a specialized manual device, and the exposed area of each sample was ground and polished in a single direction 10 times. This method facilitated the attainment of a flat surface on each sample suitable for microhardness measurement.[16]

 

Scroll to top

White Spot Lesion Formation

The pH-cycling procedure was employed to induce white spot lesion on the enamel of each sample. The demineralizing solution was prepared by combining 0.075 M/L acetic acid, 1.0 M/L calcium chloride, and 2.0 mM/L phosphate chloride, with the pH adjusted to 4.3 at 37°C. The remineralizing solution was prepared by mixing 0.9 mM/L potassium phosphate, 1.5 mM/L of calcium nitrate, and 150 mM/L potassium chloride, with a pH of 7 at 37°C. The samples were submerged in 20 mL of the demineralization solution for 6 hours at 37°C in an incubator. After this period, the samples were washed with de-ionized water for 1 minute. The samples were then submerged in a remineralizing solution for 17 hours at 37°C and stored in an incubator. This entire procedure was replicated on a daily basis for a period of 10 days. The samples were then thoroughly rinsed with de-ionized water, after which the sample was examined using a stereomicroscope to detect any microscopic alteration related to caries development, which may be visually detected as white spots upon drying.[17]

 

Scroll to top

Treatment Groups after White Spot Lesion Formation

In this study, 36 tooth samples were utilized and assigned into two groups (n = 18): one group treated with resin infiltrant and the other with fluoride varnish. Each group was then subdivided into three subgroups (n = 6) based on storage time in artificial saliva (1-week, 2-week, and 4-week). The resin infiltrant was applied following the manufacturer's instructions as follows: Icon-etch (15% HCL gel) was applied first for 2 minutes and then air-dried for 30 seconds. The second step involved the application of Icon-dry (99% ethanol) for 30 seconds, followed by air-drying. The final step involved the application of Icon-infiltrant for 3 minutes, which was then light-cured for 40 seconds using a Woodpecker LED.Q curing unit (Guilin Woodpecker Medical Instrument Co., Ltd., Guilin, China) with a light intensity of 1,000 to 1,200 mW/cm², before the treated samples were stored in artificial saliva ([Fig. 1]). In the second group, fluoride varnish was applied as a thin layer over the circular window on the buccal surface of each tooth sample ([Fig. 2]). The detailed composition and manufacturer information of the materials used in this study are presented in [Table 1].

Fig. 1 Application process of the resin infiltrant following the manufacturer's instructions.

Fig. 2 Application of fluoride varnish on the circular window of the buccal surface.

Table 1 Composition and manufacturer information of the materials used in the study

Material	Manufacturer	Composition
Resin infiltrant	DMG, Hamburg (Germany)	Icon-etch: 15% hydrochloric acid. Icon-dry: 99% ethanol (alcohol). Icon-infiltrant: triethylene glycol dimethacrylate. Initiators and stabilizers
Fluoride varnish (FluoroDose)	Centrix Inc. (United States)	5% Sodium fluoride (NaF) or 22,600 ppm of fluoride, Beeswax, coloring agent.
Artificial saliva	Prepared in laboratory	0.030 g glucose, 0.580 g NaCl, 0.002 g ascorbic acid, 0.170 g CaCl2, 0.330 g KH2PO4, 0.340 g Na2HPO4, 0.160 g NaSCN, 0.160 g NH4Cl, 1.270 g KCl, 0.200 g urea, and 2.700 g mucin in 1,000 mL distilled water.

Abbreviations: CaCl₂, calcium chloride; KCl, potassium chloride; KH₂PO₄, potassium dihydrogen phosphate; Na₂HPO₄, sodium hydrogen phosphate; NaCl, sodium chloride; NaSCN, sodium thiocyanate; NH₄Cl, ammonium chloride; ppm, parts per million.

 

Scroll to top

Microhardness Testing

Microhardness measurements were conducted utilizing a Vickers microhardness testing device (Model: TH715, SN: 0003, Beijing Time High Technology Ltd, China) in the Department of Material Engineering at Technology University ([Fig. 3]). A load of 500 g for 30 seconds was used.[18] The enamel microhardness was initially measured at the baseline, followed by assessment after induction of carious lesions using the pH cycling method. Finally, measurements were taken after the samples were treated with study materials at various storage times (1-week, 2-week, and 4-week). Three Vickers indentations were performed on each sample, and the hardness value was calculated by averaging three readings.[19]

Fig. 3 Vickers microhardness testing device.

 

Scroll to top

Statistical Analysis

Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) version 28, with the significance level set at p ≤0.05. Data are shown as means ± standard deviations. A paired t-test was employed to compare the mean enamel microhardness at the baseline, after demineralization, and after treatment for each group at each time interval. An independent sample t-test was used to compare the effect of the materials after the treatment.

 

Scroll to top

 

Scroll to top

Results

The mean microhardness values of intact enamel, subsequent to demineralization through the pH cycling procedure and following the application of resin infiltrant, are represented in [Table 2]. A statistically significant reduction in the enamel microhardness was observed following the demineralization process for all storage time intervals. Subsequently, an elevation in the mean microhardness values was recorded following the treatment with resin infiltrant at various storage times, which was statistically significant ([Fig. 4]). The values of the paired t-test are seen in [Table 3].

Table 2 Microhardness mean values and standard deviation of enamel surface treated with resin infiltrant at different storage times

Phases	1-week mean ± SD	2-week mean ± SD	4-week mean ± SD
Sound enamel	303.6 ± 26.7	301.1 ± 11.7	295.3 ± 27.3
Demineralization	94.4 ± 72.9	87.7 ± 42.7	132.9 ± 54.6
Posttreatment	154.1 ± 83.6	185.1 ± 65.7	243.4 ± 71.05

Abbreviation: SD, standard deviation.

Fig. 4 Microhardness of the resin infiltrant at different storage times for the baseline, pH cycling, and after treatment.

Table 3 Paired t-test among phases of microhardness for resin infiltrant group

Phases	1-week		2-week		4-week
	MD	p-Value	MD	p-Value	MD	p-Value
Sound × demineralization	209.13	0.001	213.4	0.001	162.4	0.001
Sound × treatment	149.5	0.001	116	0.001	51.9	0.001
Demineralization × treatment	−59.7	0.001	−97.3	0.001	−110.5	0.001

Abbreviation: MD, mean difference.

Note: Paired t-test. p-Value <0.05 is considered significant.

The microhardness means values for sound enamel, subsequent to the pH cycling procedure and after treatment with the fluoride varnish, are presented in [Table 4]. A statistically significant reduction in the microhardness was observed following the pH cycling procedure. Conversely, a statistically significant increase in microhardness was noted after the treatment for all storage time intervals ([Fig. 5]). The values of the paired t-test are shown in [Table 5].

Table 4 Microhardness mean values and standard deviation of enamel surface treated with fluoride varnish at different storage times

Phases	1-week mean ± SD	2-week mean ± SD	4-week mean ± SD
Sound enamel	262.8 ± 62.3	257.1 ± 79.4	252.1 ± 40.1
Demineralization	66.7 ± 28.6	141.2 ± 53.9	69.6 ± 32.2
Post treatment	140 ± 38.4	186.4 ± 46.4	129.8 ± 78.8

Abbreviation: SD, standard deviation.

Fig. 5 Microhardness of the fluoride varnish at different storage times for the baseline, pH cycling, and after treatment.

Table 5 Paired t-test among phases of microhardness for fluoride varnish group

Phases	1-week		2-week		4-week
	MD	p-Value	MD	p-Value	MD	p-Value
Sound × demineralization	196.1	0.001	115.9	0.001	182.5	0.001
Sound × treatment	122.8	0.001	70.70	0.001	122.3	0.001
Demineralization × treatment	−73.3	0.001	−45.22	0.001	−60.18	0.001

Abbreviation: MD, mean difference.

Note: Paired t-test. p-Value <0.05 is considered significant.

After treatment, an independent t-test revealed that 4-week remineralization period showed statistically significant differences between study materials (p < 0.001). However, no significant differences were found at 1-week and 2-week remineralization periods (p = 0.5 and p = 0.9), respectively ([Table 6] and [Fig. 6]).

Table 6 Independent sample t-test between groups after intervention

Groups	Time intervals	MD	p-Value
Resin infiltrant	1-week	14.1	0.5
Fluoride varnish
Resin infiltrant	2-week	−1.3	0.9
Fluoride varnish
Resin infiltrant	4-week	113.6	<0.001
Fluoride varnish

Abbreviation: MD, mean difference.

Note: Independent sample t-test. p-Value <0.05 is considered significant.

Fig. 6 Microhardness of enamel surface for both groups after treatment.

 

Scroll to top

Discussion

Preventing dental caries is more crucial than its treatment. In children and adolescents, preventive strategies can effectively halt early caries development and facilitate the remineralization of damaged dental surfaces. The use of preventive materials to remineralize the white spot lesions and early enamel decay can slow or even prevent the development of cavities while maintaining the structural integrity of the tooth. Microhardness measurement is commonly used as a criterion to evaluate the effectiveness of various remineralizing agents in halting demineralization and reversing lesions.[20] In the present study, carious lesion initiation was achieved using the pH cycling method, which has been validated in previous studies[17] [21] for its ability to induce enamel demineralization. This method is widely recognized for its simplicity, reliability, and effectiveness in simulating the development of dental caries. A statistically significant reduction in the enamel microhardness was noted following the pH cycling in both groups, indicating enamel demineralization and the initiation of a carious lesion. When the pH of the surrounding environment drops below the critical threshold of 5.5, it creates an acidic environment that promotes demineralization by causing the loss of calcium and phosphate ions. This process leaves micropores in the enamel, resulting in decreased hardness.[22] Following demineralization, studies[23] [24] have shown that enamel microhardness significantly decreases while lesion depth increases due to mineral loss. Conversely, after applying remineralizing treatments, an increase in surface microhardness and a corresponding reduction in lesion depth have been observed, reflecting the restoration of mineral content and enamel integrity.

Enamel microhardness was evaluated for each material across different time intervals. Each material was analyzed separately over time, and comparisons were made between materials at each time point. Therefore, the results reflect main effects only.

In the group treated with resin infiltrant, the results demonstrated a statistically significant elevation in the enamel mean microhardness compared with the demineralized stage for all time intervals. This is due to the inherent capacity of the resin infiltrant to penetrate the microporosities present in the demineralized enamel, facilitated by its low viscosity, which creates a diffusion barrier within the enamel lesion. This process ultimately leads to rehardening of the demineralized tissue, thereby enhancing its mechanical integrity and preventing cavitation. These outcomes aligned with the studies conducted by Torres et al and Paris et al.[25] [26] However, the microhardness did not reach the baseline level, a result that is in accordance with the finding of Neres et al.[27] This may be due to certain regions of demineralized enamel that remained unfilled by the resin during the polymerization process, a phenomenon attributed to the material shrinkage, as discussed by Torres et al.[25] Additionally, the organic matrix of resin infiltrant, predominantly consisting of triethylene glycol dimethacrylate (TEGDMA), may not always form a consistent polymer chain from this monomer.[28] Furthermore, the mechanical characteristics of this monomer are comparatively inferior to those of alternative monomers; a condition resulting from the lack of strong intermolecular secondary bonds and aromatic structure.[29] The results of the present study demonstrated that the resin infiltrant group showed the highest microhardness at 4-week followed by 2-week, while it provided lowest microhardness at 1-week. This can be explained by the ability of the TEGDMA monomer of resin infiltrant to continue polymerization even after the initial curing, which can increase hardness over time. This post-curing polymerization effect strengthens the infiltrated enamel by creating a more cross-linked polymer matrix, peaking at around 4-week.[30] These findings are in contrast with the findings of Pintanon et al,[31] who concluded that resin infiltrant provides an immediate increase in the microhardness of white spot lesions, which then decreases over time.

When sodium fluoride varnish was applied, a notable increase in mean microhardness values was observed compared with the demineralized phase. This can be attributed to the chemical interaction between the fluoride ion and the enamel surface, resulting in the formation of fluoride-containing compounds, primarily calcium fluoride. These compounds serve as reservoirs of fluoride ions, subsequently hindering the further dissolution of enamel during an acidic attack.[32] [33] The results of the present study aligned with the findings of Kamal et al and Oliveira et al.[34] [35]

After treatment, there were no significant differences between the two groups at both 1-week and 2-week intervals. This may be due to the short duration, which is not enough to show a clear difference between the materials, or it may be due to the physical or chemical properties of each material, which may lead to similar effects in the early stages, as both may interact with the surface in the same ways, without deep penetration or sufficient interaction to show a significant difference. However, at the 4-week mark, a significant difference with resin infiltrant demonstrating a greater effect, this finding is aligned with the result of Aziznezhad et al,[36] who found that surface microhardness was significantly higher after treatment with resin infiltrant compared with fluoride varnish. Furthermore, the study conducted by Manav Özen et al[37] supports the long-term effectiveness of resin infiltrant in improving enamel surface hardness compared with fluoride-based treatment. This can be explained by the formation of homogenous resin–hydroxyapatite complex, exhibiting enhanced surface hardness. The formation of resin–hydroxyapatite complex occurs through the encapsulation of hydroxyl-apatite crystals by resin infiltration material.[38] In contrast, the fluoride varnish exhibited a decrease in effectiveness, as its effect gradually disappeared when the applications stopped, necessitating regular reapplication to maintain its effects.[39] Although the study by Kashash et al[40] focused on color change, it similarly showed that fluoride varnish had less long-term effectiveness compared with resin infiltration. In our study, while microhardness showed no significant difference between materials during the first 2 weeks, a significant improvement was observed with resin infiltration at 4 weeks, supporting the concept that resin infiltration provides better long-term outcomes in both structural and esthetic aspects.

 

Scroll to top

Conclusion

In conclusion, both resin infiltrant and fluoride varnish positively contributed to the enhancement of the enamel microhardness. However, resin infiltrant demonstrated a more consistent increase in the microhardness over time, indicating its potential for effective long-term remineralization.

 

Scroll to top

 

Scroll to top

Conflict of Interest

None declared.

Acknowledgment

The authors would like to thank Mustansiriyah University (http://WWW.Uomustansiriyah.edu.iq) Baghdad-Iraq for its support in the present work.

Ethical Approval

This study received review and approval from the Research Ethics Committee of the College of Dentistry (approval Number: REC140). The research adheres to the current Human Research Guideline, with full ethical approval granted on December 1, 2023. All methods were performed in accordance with relevant guidelines and regulations.

• References

• 1 Jamal Abbas M, Khairi Al-Hadithi H, Abdul-Kareem Mahmood M, Mueen Hussein H. Comparison of some salivary characteristics in iraqi children with early childhood caries (Ecc) and children without early childhood caries. Clin Cosmet Investig Dent 2020; 12: 541-550
• 2 Al-Ghurabi BH, Aldhaher ZA, Kareem MWA. et al. Effect of vitamin D on salivary cathelicidin in kindergarten children with dental caries. J Emerg Med Trauma Acute Care 2024; 2024 (02) 14
• 3 Fejerskov O, Nyvad B, Kidd E. Dental Caries: the Disease and its Clinical Management. Chichester, West Sussex, UK: John Wiley & Sons; 2015
• 4 Marinelli G, Inchingolo AD, Inchingolo AM. et al. White spot lesions in orthodontics: prevention and treatment. A descriptive review. J Biol Regul Homeost Agents 2021; 35 (2, Suppl. 1): 227-240
• 5 Al-Khannaq MRA, Nahidh M, Al-Dulaimy DA. The importance of the maxillary and mandibular incisors in predicting the canines and premolars crown widths. Int J Dent 2022; 2022 (01) 1551413
• 6 Haberal M. White spot lesions: diagnosis and treatment methods. KÜ Tıp Fak Derg 2024; 26 (01) 109-116
• 7 Puleio F, Fiorillo L, Gorassini F. et al. Systematic review on white spot lesions treatments. Eur J Dent 2022; 16 (01) 41-48
• 8 Anil A, Ibraheem WI, Meshni AA, Preethanath R, Anil S. Demineralization and remineralization dynamics and dental caries. Dental Caries-The Selection of Restoration Methods and Restorative Materials. London, UK: IntechOpen; 2022: 1-19
• 9 Buzalaf MAR. Fluoride and the Oral Environment. Vol 22. Basel: Karger Medical and Scientific Publishers; 2011
• 10 Almallah LAA. Topical effect of silver diamine fluoride in preventing and arresting root caries in elderly patients. Mustansiria Dent J 2021; 17 (01) 50-57
• 11 Ibrahim DFA, Liew Y, Hasmun N, Venkiteswaran A. Resin infiltration ICON®: a guide for clinical use. Mal J Paed Dent 2023; 2 (01) 27-35
• 12 Faul F, Erdfelder E, Buchner A, Lang A-G. Statistical power analyses using G*Power 3.1: tests for correlation and regression analyses. Behav Res Methods 2009; 41 (04) 1149-1160
• 13 Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2nd ed.. New York, USA: Routledge; 2013
• 14 Jasim HH. Fracture resistance of premolars restored with inlay/onlay composite and lithium disilicate CAD/CAM block restorations (an in vitro study). Mustansiria Dent J 2023; 19 (02) 176-193
• 15 Barbakow F, Sener B, Lutz F. Dissolution of phosphorus from human enamel pretreated in vitro using SnF2 stabilized with amine fluoride 297. Clin Prev Dent 1987; 9 (05) 3-6
• 16 Al-Rawi NA, Al-Alousi JMR, Al-Obaidy NM. Effect of Zamzam water on the microhardness of initial carious lesion of permanent teeth enamel (an in vitro study). Mustansiria Dent J 2009; 6 (02) 110-116
• 17 Athraa'M A-W, Fahad AH. Effect of zamzam water on the microhardness of initial caries-like lesion of permanent teeth, compared to casein phosphopeptide-amorphous calcium phosphate agents. J Bagh Coll Dent 2012; 24: 128-132
• 18 Chuenarrom C, Benjakul P, Daosodsai P. Effect of indentation load and time on knoop and vickers microhardness tests for enamel and dentin. Mater Res 2009; 12: 473-476
• 19 Hashim AR, Mansoor NS. Effect of different surface treatments on surface roughness and vickers micro-hardness of feldspathic porcelain: an in vitro study. Mustansiria Dent J 2021; 17 (01) 36-50
• 20 Kooshki F, Pajoohan S, Kamareh S. Effects of treatment with three types of varnish remineralizing agents on the microhardness of demineralized enamel surface. J Clin Exp Dent 2019; 11 (07) e630-e635
• 21 Al Anni MJ. Effect of water extracts of cinnamon on the microhardness of initial carious lesion of permanent teeth, compared to stannous fluoride (An in vitro study). J Bagh Coll Dent 2011; 23 (01) 120
• 22 Li X, Wang J, Joiner A, Chang J. The remineralisation of enamel: a review of the literature. J Dent 2014; 42 (Suppl. 01) S12-S20
• 23 Al-Mamoori RMH, Al Haidar AHM. Effect of resin infiltration and microabrasion on the microhardness of the artificial white spot lesions (an in vitro study). J Bagh Coll Dent 2022; 34 (01) 44-50
• 24 Ersen MC, Çelik ZC, Oztas M, Sahin M, Tagtekin D, Yanikoglu F. Impact of demineralization time on enamel microhardness reduction and lesion depth: an in vitro study. Cureus 2025; 17 (02) e79441
• 25 Torres CR, Rosa PC, Ferreira NS, Borges AB. Effect of caries infiltration technique and fluoride therapy on microhardness of enamel carious lesions. Oper Dent 2012; 37 (04) 363-369
• 26 Paris S, Schwendicke F, Seddig S, Müller W-D, Dörfer C, Meyer-Lueckel H. Micro-hardness and mineral loss of enamel lesions after infiltration with various resins: influence of infiltrant composition and application frequency in vitro. J Dent 2013; 41 (06) 543-548
• 27 Neres ÉY, Moda MD, Chiba EK, Briso A, Pessan JP, Fagundes TC. Microhardness and roughness of infiltrated white spot lesions submitted to different challenges. Oper Dent 2017; 42 (04) 428-435
• 28 Paris S, Lausch J, Selje T, Dörfer CE, Meyer-Lueckel H. Comparison of sealant and infiltrant penetration into pit and fissure caries lesions in vitro. J Dent 2014; 42 (04) 432-438
• 29 Chabuk MM, Al-Shamma AM. Surface roughness and microhardness of enamel white spot lesions treated with different treatment methods. Heliyon 2023; 9 (07) e18283
• 30 Aromaa MK, Vallittu PK. Delayed post-curing stage and oxygen inhibition of free-radical polymerization of dimethacrylate resin. Dent Mater 2018; 34 (09) 1247-1252
• 31 Pintanon P, Sattabanasuk V, Banomyong D. Effectiveness of caries infiltration and CPP-ACP containing paste on color change and surface hardness of artificial white spot enamel lesions. J Dent Assoc Thai 2016; 66 (02) 133-148
• 32 Abdul-Razzaq SA, Khalaf MS. Efficacy of silver diamine fluoride on immediate and delayed adhesive strength of resin composite to sound dentin of permanent teeth: an in vitro study. Mustansiria Dent J 2024; 20 (01) 61-72
• 33 Chaudhary A, Ingle NA, Kaur N, Gupta R. Effect of fluoridated dentifrices on microhardness of enamel surface: invitro study. J Adv Oral Res 2013; 4 (01) 11-16
• 34 Oliveira MRC, Oliveira PHC, Oliveira LHC. et al. Microhardness of bovine enamel after different fluoride application protocols. Dent Mater J 2019; 38 (01) 61-67
• 35 Kamal D, Hassanein H, Elkassas D, Hamza H. Comparative evaluation of remineralizing efficacy of biomimetic self-assembling peptide on artificially induced enamel lesions: an in vitro study. J Conserv Dent 2018; 21 (05) 536-541
• 36 Aziznezhad M, Alaghemand H, Shahande Z. et al. Comparison of the effect of resin infiltrant, fluoride varnish, and nano-hydroxy apatite paste on surface hardness and streptococcus mutans adhesion to artificial enamel lesions. Electron Physician 2017; 9 (03) 3934-3942
• 37 Manav Özen A, Doğu Kaya B, Yılmaz Atalı P, Türkmen C. Evaluation of NaOCl application prior to resin infiltrant or fluoride-containing resin varnish in the treatment of white spot lesions: an in vitro study. J Dent 2025; 156: 105641
• 38 Venter SAdS, Fávaro SL, Radovanovic E, Girotto EM. Hardness and degree of conversion of dental restorative composites based on an organic-inorganic hybrid. Mater Res 2013; 16: 898-902
• 39 Miller FY, Campus G, Giuliana G, Piscopo MR, Pizzo G. Topical fluoride for preventing dental caries in children and adolescents. Curr Pharm Des 2012; 18 (34) 5532-5541
• 40 Kashash Y, Hein S, Göstemeyer G, Aslanalp P, Weyland MI, Bartzela T. Resin infiltration versus fluoride varnish for visual improvement of white spot lesions during multibracket treatment. A randomized-controlled clinical trial. Clin Oral Investig 2024; 28 (06) 308

Publikationsverlauf

Artikel online veröffentlicht:
17. Oktober 2025