Color Stability and Durability of Dental Restorative Materials against Pediatric Liquid Drugs

ABSTRACT

Objective:  To evaluate the color stability, surface roughness, and microhardness of dental restorative materials in various pediatric liquid drugs (PLDs).

Material and Methods:  A total of 175 restorative material discs were prepared for the following groups (n=25): Filtek Ultimate (FU), ACTIVA BioACTIVE Restorative (AC), ADMIRA Fusion X-tra (AD), Beautifil II (BII), Equia Forte (EQ), Fujı II Lc (FII), Fuji IX (FIX). After the initial colour assessment was performed, surface roughness and microhardness values were measured. Specimens were divided into five subgroups (n = 5) for each test, including Aerius, Ferrosanol, Atarax, Keppra, and Ventolin. Measurements were repeated following a 4-week immersion cycle. The resulting data were analyzed statistically using the Shapiro-Wilk, Kruskal-Wallis, and Friedman tests.

Results:  The FII group showed the highest ΔE. However, there was no significant difference between the BII and EQ groups (p>0.05). The Ferrasanol B caused the most significant color change in materials (p < 0.05). The Ventolin significantly increased the surface roughness of the materials (p < 0.05). Following the PLD storage, the surface roughness of the BII and FIX groups increased, while the microhardness of the FU, BII, EQ, and FII groups decreased (p < 0.05). The Aerius, Atarax, Keppra, and Ventolin significantly disrupted the microhardness of the materials (p < 0.05).

Conclusion:  Pediatric liquid drugs may cause unfavorable effects on the color stability and surface properties of restorative materials.

Keywords:
Pediatric Dentistry; Dental Materials; Oral Health

Introduction

Novel approaches in material science focused on enhancing the restorative material's properties, such as color, morphology, and strength, to mimic natural teeth [¹]. Thanks to the advancement of dental restorative materials, it is now possible to recover function and achieve an ideal anatomical form with minimal removal of tooth structure, in line with the concept adopted by minimal intervention dentistry [²]. For this purpose, it has become preferable for a restorative material to induce bio-remineralization via a sufficiently significant ionic release. Ion-releasing restorative materials have been continuously investigated and optimized for both ion release and mechanical properties, thereby preventing recurrent caries and demonstrating an improved ability to withstand higher masticatory forces [³].

Despite significant advancements in the composition and properties of dental restorative materials, disintegration or dissolution caused by the acidity produced by foods, drinks, and bacteria has a profound impact on the durability of restorations [⁴]. The chemical environment, a component of the oral environment, may cause the in vivo degradation of restorative materials [⁵]. A low pH promotes the development of erosion in tooth hard tissues and biodegradation of the materials [⁶]. The resistance of restorative materials to degradation contributes to the longevity of the restoration, making them preferable [⁷].

Children with chronic diseases and recurrent benign pathologies may require pediatric liquid drugs (PLDs) daily [⁸]. One of the biggest challenges of administering medicine to children is a "matter of taste." To minimize the unpleasant taste of bitterness, PLDs are typically colored, flavored, and sweetened with various excipients, in addition to containing the main active ingredients [⁹]. Moreover, acids are commonly added to PLDs to improve flavor, ensure physiological compatibility, control tonicity, and maintain chemical stability. The properties of the acid, including its relative strength, pH, and titratable acidity, contribute to its erosive potential in the oral environment [¹⁰].

Determining the resistance of various restorative materials to degradation in different PLDs is crucial for the longevity of restorations and for enhancing clinical outcomes. Insufficient data in the literature justify further research on this matter. Therefore, the purpose of this in vitro study was to assess the effect of PLDs on the microhardness, surface roughness, and color stability of restorative materials.

Material and Methods

The details of PLDs (Aerius, Atarax, Ferrosanol B, Keppra, Ventolin) and restorative materials (FU, Filtek Ultimate; AC, ACTIVA Kids BioACTIVE Restorative; AD, ADMIRA Fusion X-tra; BII, Beautifil II; EQ, Equia Forte; FII, Fujı II Lc; FIX; Fuji IX) used in the study are given in Tables 1 and 2, respectively.

Table 1
Pediatric liquid drugs used in the study.

PLDs	Brand Name	Generic Name	Composition
Antihistamine	Aerius	Desloratadin	Desloratadine, anhydrous citric acid, sodium citrate, sucrose, sodium benzoate, disodium edetate, sorbitol, cantaloupe colorant
Anxiolytic	Atarax	Hydroxyzine HCL	Hydroxyzine dihydrochloride, ethanol, sucrose, sodium benzoate, levomenthol, hazelnut flavor
Antianemic-Multivitamin	Ferrosanol B	Ferroglikol Sülfat	Iron (II)-glycine-sulphate-complex, vit. B1, vit. B6 ascorbic acid, refined sugar, glucose monohydrate, sorbitol, sulfuric acid
Antiepileptics	Keppra	Levetiracetam	Levetiracetam, sodium citrate, citric acid monohydrate, methyl parahydroxybenzoate, glycerol
Bronchodilator	Ventolin	Salbutamol	Salbutamol sulfate, sodium citrate dihydrate, citric acid monohydrate, sodium benzoate, sodium saccharin, orange flavor

Table 2
Restorative materials used in the study.

Product	Material Type	Composition	Manufacturer
Filtek Ultimate	Nanofill composite resin	Bis-GMA, UDMA, Bis-EMA, PEGDMA and TEGDMA. 78.5 wt% 20 nm silica and 4 to 11 nm zirconia particles	3M/ESPE, St. Paul, MN, USA
ACTIVA Bioactive-Restorative	Bioactive restorative material	Blend of diurethane and other methacrylates with modified polyacrylic acid. 55.4 wt% Bioactive glass and sodium fluoride	Pulpdent, Watertown, MA, USA
Admira Fusion X-tra	Ormocer	Resin ormocer, 84 wt% silicon oxide nanofiller, and glass ceramics filler (1 μm)	Voco GmbH, Cuxhaven, Germany
Beautifil II	Giomer	Bis-GMA, UDMA, Bis-MPEPP, TEGDMA. 83.3 wt% Fluoro-silicate glass	Shofu Inc., Kyoto, Japan
Equia Forte	Glass hybrid	Carboxylic acid, polyacrylic acid, distilled water. Fluoro-aluminosilicate glass surface treated glass (wt% not applicable)	GC Corporation, Tokyo, Japan
Fuji II LC	Resin-modified glass ionomer cement	2-hydroxyethyl methacrylate, Polyacrylic acid, and distilled water. 58 wt% Fluoro-aluminosilicate glass	GC Corporation, Tokyo, Japan
Fuji IX	Glass-ionomer cement	Polyacrylic acid, polybasic polycarboxylic acid, and distilled water, Fluoro-aluminosilicate glass.	GC Corporation, Tokyo, Japan

• UDMA: Urethane Dimethacrylate; BisGMA: Bisphenol-A Glycol Dimethacrylate; Bis-MPEPP: Bisphenol A Polyethoxy; TEGDMA: Triethylene Glycol Dimethacrylate; 4-MET: 4-[2-(methacryloyloxy)ethoxycarbonyl] phthalic acid; MDTP: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; 10-MDP: 10-methacryloyloxydecyl dihydrogen phosphate.

Specimen Preparation

A total of 175 restorative material discs (n = 25 for each material) were used for each color change, surface roughness, and microhardness test. The sample size was estimated using G Power 3.1.9.7 (developed by Franz Faul, University of Kiel, Germany) with a power of 0.90% and an alpha error probability (Type I error) of 0.05%. The discs were prepared using a circular silicon mold with a diameter of 10 mm and a height of 2 mm (Figure 1). The materials were placed into a mold with a slight overflow. A mylar strip was placed onto both surfaces for the following step. The excess material was removed by applying pressure with a glass layer. All specimens were prepared according to the manufacturer's recommendations, and an LED device (Valo Cordless, Ultradent Products Inc., South Jordan, UT, USA) with a standard power of 1000 mW/cm² was used for light-cured materials. Before initiating the experimental procedures, the LED light-curing device was calibrated to ensure consistent light output throughout the study. A dental radiometer (SDI, Bayswater, Australia) was used to measure the light intensity in milliwatts per square centimeter (mW/cm²). The light guide tip was positioned perpendicular to the radiometer sensor, and three consecutive readings were recorded. The average value was calculated to verify that the output was within the manufacturer's recommended range (e.g., 1000 ± 50 mW/cm²). To maintain accuracy, the light tip was inspected and cleaned using an alcohol wipe before each use to remove any debris or resin remnants that could interfere with light transmission. The device's battery was fully charged before each curing cycle to avoid fluctuations in power output. This calibration process was repeated daily during the study period to ensure consistent polymerization conditions across all specimens [¹¹]. Cured specimens were stored in distilled water at 37°C for 24 hours to complete the polymerization. Specimens were then subjected to finishing and polishing processes under constant water cooling to remove the resin-rich layer and achieve a glossy surface using a micromotor (with light hand pressure and one-way rotation movement at low speed) and polishing discs. After each disc application, the specimens were washed for 10 s and air-dried for 5 s.

Figure 1
Teflon mold and samples used for measurements.

Color Change

The baseline color values of the samples were recorded after the polymerization of the restorative materials had been completed. According to the Commission Internationale de l'Eclairage L*a*b* (CIE Lab) scale, color measurements were performed using a spectrophotometer (VITA EasyShade Advance; VITA Zahnfabrik, Bad Sackingen, Germany). The spectrophotometer was calibrated before the measurements, and each sample was positioned centrally. According to the CIE Lab color space, the digital image analysis method was used to assess the color of specimens. The CIE Lab system, a chromatic value color space, measures chroma and value in three coordinates: L* represents lightness or brightness (value), a* and b * serve as numeric correlates for chroma and hue. A position on a red/green and yellow/blue axis is represented by the a* and b* values, respectively. Thus, ΔE* (the magnitude of the color difference) perceived between two objects is calculated. The calculation of ΔE* was done using the following equation: ΔE (L * a * b*) = ([ΔL*]²+ [Δa*]²+ [Δb*]²)^½ where ΔL* = L₁ – L₀, Δa* = a₁ – a₀ and Δb*=b₁–b₀ [¹²] L₀, a₀ and b₀ were the initial measured color data. L₁, a₁, and b₁ were the measured color data of the specimens subjected to PLDs.

Surface Roughness

The surface roughness of the specimens was measured using a mechanical profilometer instrument (SurftestSJ-400, Mitutoyo Corp., Kawasaki, Japan), with a measuring distance of 4 mm and a cut-off length of 0.8 mm. Three successive measurements of the center of each disk were taken to obtain the mean values of surface roughness (Ra) for each sample, and these values were then averaged. Ra values were recorded in μm. This measurement was taken both before and after immersion in PLD.

Surface Microhardness

A microhardness tester (LHV-1D, URNDT Co., Ltd., PR China) with a diamond Vickers indenter was used to determine the microhardness values of each specimen. With a 200 g load for a 10 s dwell time, three indentations were measured at different points on each specimen, and these values were averaged. A Vickers Hardness Number was obtained by converting the average value. This measurement was taken both before and after immersion in PLD.

After completing the initial color, surface roughness, and microhardness measurements of each restorative material specimen (n = 25 for each test), they were divided into five subgroups (n=5), including Aerius, Ferrosanol B, Atarax, Keppra, and Ventolin. The pH of each PLD was measured prior to the study using a pH meter (InoLab pH/Cond 720, Xylem Analytics Germany Sales GmbH & Co., Weilheim, Germany). pH values for Aerius, Atarax, Ferrosanol B, Keppra, and Ventolin were measured as 4.75, 1.33, 1.65, 4.96, and 2.58, respectively. Restorative materials were then immersed in 5 different undiluted pediatric liquids for 2 min every 8 hours [¹³-¹⁵]. The immersion duration for the present investigation was established at 4 weeks to reflect the clinical context in which children are frequently exposed to the most prevalent PLDs. The samples were stored in distilled water between immersion periods. After cumulative immersion, measurements for each material were repeated. Data were obtained using the same method as described for the initial measurements.

Statistical Analysis

The statistical package SPSS for Windows, version 22 (IBM Corp., Armonk, NY, USA) was used to analyze the data collected in this study. The Shapiro-Wilk test was used to determine whether or not the calculated data followed a normal distribution. Then, the Kruskal-Wallis test was used to analyze the color change, and the Friedman test was employed to examine surface roughness and microhardness. The level of confidence was set at 95 percent.

Results

Color Change

The ΔE values of the tested restorative materials are given in Table 3. There was no significant difference between materials in the Atarax, Keppra, and Ventolin liquids (p > 0.05). The highest ΔE was obtained from the EQ group in the Aerius liquid. There was a statistically significant difference between the AC and EQ groups and the EQ and FIX groups (p<0.05). In the Ferrosanol B liquid, the highest ΔE was obtained from the FII group. There was a statistically significant difference between the AC and EQ groups, the AC and FII groups, and the FU and FII groups (p < 0.05).

Table 3
Mean (standard deviation) ΔE values of restorative materials.

Material	Aerius	Ferrosanol B	Atarax	Keppra	Ventolin	Total
FU	2.09±1.33	2.37±0.23A	1.72±1.23	2.52±1.42	2.51±1.17	2.24±1.10 †
AC	1.42±1.01A	1.69±0.72BC	1.34±0.24a	2.42±1.00	3.26±0.98a	2.02±1.07 †
AD	1.76±0.94	2.82±1.53	2.95±1.46	2.01±1.59	2.35±1.32	2.38±1.35 †
BII	4.18±0.88 a	2.92±0.53	2.35±0.75a	2.79±0.66	2.64±0.76	2.98±0.92 † ‡
EQ	5.51±1.33AB	6.05±2.07Ba	2.93±1.16	2.57±1.07a	4.14±0.61	4.24±1.85 ‡
FII	3.59±1.06	10.82±1.71ACab	2.45±0.96a	3.11±0.64b	4.63±1.18	4.92±3.27 ‡
FIX	1.56±0.90B	2.62±1.21	2.30±1.20	2.68±0.64	2.79±1.82	2.39±1.20 †
Total	2.87±1.77	4.18±3.26a	2.29±1.12a	2.59±1.02	3.19±1.35

• FU: Filtek Ultimate; AC: Activa BioACTIVE Restorative; AD: Admira Fusion X-tra; BII: Beautifil II; EQ: Equia Forte; FII: Fuji II Lc; FIX: Fuji IX; The same superscript capital letters (A, B, C) mean the statistical difference in each column (p < 0.05); The same superscript lowercase letters (a, b, c) mean the statistical difference in each row (p < 0.05); The different superscript symbols (†, ‡) mean the statistical difference in the total column (p < 0.05).

The AC group showed a higher ΔE in the Ventolin liquid compared to the Atarax liquid (p < 0.05). The BII group showed a higher ΔE in the Aerius liquid than the Atarax liquid (p < 0.05). The EQ group showed a higher ΔE in the Ferrosanol B liquid compared to the Keppra liquid (p < 0.05). The FII group showed a higher ΔE in Ferrosanol B liquid than in the Atarax and Keppra liquids (p < 0.05). After PLD storage, there were no significant differences in the FU, AD, and FIX groups (p > 0.05).

The FII group showed the highest ΔE. However, there was no statistically significant difference between the BII and EQ groups(p > 0.05). The Ferrasanol B liquid caused a higher ΔE in the materials than the Atarax liquid (p < 0.05).

Surface Roughness

After PLD storage, the surface roughness of the BII and FIX groups increased significantly (p < 0.05; Table 4), and Ventolin caused a significant increase in the surface roughness of the restorative materials (p < 0.05; Table 5).

Table 4
Mean (standard deviation) values of surface roughness and microhardness of the restorative materials in all pediatric liquid drugs.

Material	Vicker’s Microhardness	Surface Roughness
FU	6.60±6.94*	-0.00±0.15
AC	1.15±2.97	0.10±0.56
AD	-1.16± 6.31	0.05±0.21
BII	7.29±4.57*	-0.11±0.21*
EQ	13.68±9.58*	-0.02±0.69
FII	5.96±5.38*	-0.03±0.49
FIX	6.97±10.77	-0.13±0.26*

• FU: Filtek Ultimate; AC: Activa BioACTIVE Restorative; AD: Admira Fusion X-tra; BII: Beautifil II; EQ: Equia Forte; FII: Fuji II Lc; FIX: Fuji IX; *Means statistical differences (between initial and after drug storage values of each material).

Table 5
Mean (standard deviation) values of surface roughness and microhardness of the restorative materials according to the pediatric liquid drugs.

Liquid Drugs	Vicker’s Microhardness	Surface Roughness
Aerius	6.23±8.44*	0.04±0.43
Atarax	6.10±7.13*	-0.03±0.29
Ferrosanol B	3.72±9.44	-0.02±0.50
Keppra	5.54±7.48*	0.04±0.55
Ventolin	7.32±8.72*	-0.12±0.22*

• ^*
  Means statistical differences (between initial and after drug storage values of each material).

Mean values of differences of the surface roughness in terms of restorative materials and the PLDs were given in Table 6. In the Atarax liquid, there was a significant increase in surface roughness of the FIX group (p < 0.05). In the Ventolin liquid, there was a substantial increase in surface roughness of the AC and BII groups (p < 0.05). Aerius, Ferrasanol, and Keppra had no significant effect on the surface roughness values of the restorative materials (p > 0.05).

Table 6
Mean (standard deviation) values of surface roughness and microhardness in terms of restorative materials and pediatric liquid drugs.

RM	Aerius		Atarax		Ferrosanol B		Keppra		Ventolin
	Hardness	Roughness	Hardness	Roughness	Hardness	Roughness	Hardness	Roughness	Hardness	Roughness
FU	5.69±6.86	0.08±0.17	8.98±5.36*	0.04±0.14	6.52 ±10.33	-0.18±0.17	6.79±6.78*	0.01±0.02	5.00±6.99	0.00±0.06
AC	1.85±5.08	0.03±0.04	1.67±2.66	0.03±0.15	-0.36±2.42	-0.08±0.05	1.82±2.73	0.64±1.20	0.76±1.44	-0.07+0.12*
AD	0.34±2.09	0.09±0.27	-1.62±6.30	-0.15±0.22	-4.94±3.51*	0.13+0.07	-2.53± 6.00	0.17±0.22	2.95±10.09	0.01±0.04
BII	8.46±2.92*	-0.12±0.28	7.58±.97*	-0.00±0.20	5.20±2.68*	-0.19+0.19	4.00±5.80	-0.04±0.12	11.22±5.91*	-0.23+0.21*
EQ	15.12±11.68*	-0.01±0.39	8.46±8.96	-0.02±0.69	15.12±9.17*	0.14±1.36	11.78±8.76*	-0.18±0.44	17.92±10.31*	-0.02±0.31
FII	2.23±3.21	0.37±0.98	5.86±4.95*	-0.10±0.23	5.92±5.36*	-0.01±0.14	6.75±8.26*	-0.13±0.31	9.05±3.45*	-0.28±0.21
FIX	9.94±12.76	-0.15±0.27	11.76±9.57	-0.07+0.08*	-1.39±13.56	-0.00±0.24	10.21±5.11*	-0.17±0.36	4.35±9.10	-0.26±0.28

• RM: Restorative Materials; FU: Filtek Ultimate; AC: Activa BioACTIVE Restorative; AD: Admira Fusion X-tra; BII: Beautifil II; EQ: Equia Forte; FII: Fuji II Lc; FIX: Fuji IX;
• ^*
  Means statistical differences (between initial and after drug storage values of each material).

Surface Microhardness

Following the PLD storage, the microhardness of the FU, BII, EQ, and FII groups decreased significantly (p < 0.05; Table 4). Additionally, the use of Aerius, Atarax, Keppra, and Ventolin resulted in a significant decrease in the microhardness values of the restorative materials (p < 0.05; Table 5).

Mean values of differences of the microhardness in terms of restorative materials and the PLDs were given in Table 6. There was a significant decrease in microhardness for the BII and EQ groups (p < 0.05). There was a substantial decrease in the Atarax liquid in the microhardness of the FU, BII, and FII groups (p < 0.05). There was a significant decrease in the microhardness of the Ferrasanol liquid in the AD, BII, EQ, and FII groups (p < 0.05). In the Keppra liquid, a significant decrease in microhardness was observed in the FU, EQ, FII, and FIX groups (p < 0.05). There was a significant decrease in the Ventolin liquid in terms of the microhardness of BII, EQ, and FII groups (p < 0.05).

Discussion

The present study evaluated the effect of PLDs on the surface microhardness, roughness, and color stability of restorative materials, establishing that these materials may interact with PLDs. The differences in color stability among restorative materials may be attributed to their degree of water sorption, depth of polymerization, dimensions of filler particles, the hydrophilicity of the matrix resin, water content, and the presence of staining agents [¹⁶]. The FII (Fuji II; Resin modified glass ionomer cement [GIC]; 4.92) and EQ (Equia Forte; High viscosity GIC; 4.24) groups had greater ΔE than 3.3, which was found to be a clinically unacceptable ΔE value previously [¹⁷-¹⁸]. It was previously reported that Fuji II and Equia Forte may cause potential discoloration under various staining conditions [¹⁶-¹⁹]. Fuji II is a hybrid material containing hydrophilic monomer hydroxyethyl methacrylate (HEMA). HEMA ingredients can make the material more susceptible to staining due to its rapid water sorption capacity [²⁰]. Restorative materials containing hydrophilic monomers show lower stain resistance and color stability than those containing hydrophobic monomers [¹⁶].

Furthermore, the permeability of the hydrogel matrix in the material's structure may allow the penetration of liquids with which the material comes into contact, resulting in the material softening and becoming colored [²¹-²²]. In the present study, the lowest ?E was observed in the ACTIVA KIDS group, consistent with the findings of Kathiria et al. [²³]. This can be explained by the theory that it has significantly lower water solubility compared to composites and GIC.

In a recent study by Almutairi et al. [²⁴], the effect of various pediatric drugs on the color stability of esthetic restorative materials used in pediatric dentistry was investigated. They found that exposure of restorative materials to liquid medications, such as iron syrups and other acidic solutions, significantly reduced color stability. Ferrosanol B showed the highest staining potential. Furthermore, Kathiria et al. [²³] also observed the effect of pediatric medications on color stability. They found that materials exposed to certain drugs experienced discoloration, highlighting the importance of considering pediatric drug composition when selecting restorative materials.

The present study observed the highest staining potential in the Ferrosanol B group for all the restorative materials tested. Similarly, Tüzüner et al. [¹³] and Yıldırım et al. [²⁵] presented the highest ΔE in iron syrups. The staining potential of drinks, drugs, and solutions varies according to their composition and characteristics [²⁶]. Jamal et al. [²⁷] also investigated the effects of pediatric liquid medications on the surface properties of dental restorations. They reported that several liquid medications, including iron-based ones, caused changes in surface properties that could impact the longevity of dental materials. This supports the present study's finding of significant staining effects in materials exposed to Ferrosanol B.

Candan and Ünal [²⁸] investigated the effects of various inhaled asthma medications on the color stability of pediatric restorative materials, including composite and glass ionomer-based systems. They observed significantly higher discoloration in materials exposed to salbutamol-based inhalers, especially in resin-modified glass ionomers. Furthermore, the Candan and Ünal [²⁸] study highlighted the importance of considering the specific formulation of asthma medications, noting that both the pH and additional chemicals, such as citric acid, could contribute to the degradation of restorative materials. This finding supports the present study's observation that citric acid, when combined with salbutamol in Ventolin, had a significant impact on the color stability and surface roughness of restorative materials. The acidic nature of these medications likely facilitated the breakdown of the glass matrix in materials like Fuji II and Equia Forte, leading to visible color changes. Roughness parameters depend on various factors, including hardness, filler particle size, filler-matrix interaction, the percentage of surface area occupied by filler particles, and the degree of polymer conversion in the resin matrix [²⁹]. In this study, the FIX (Fuji IX; conventional GIC) and BII (Beautiful II; giomer) groups exhibited significantly decreased surface roughness than the initial values. When conventional GIC comes into contact with acidic solutions, the H+ ion spreads to the material, resulting in replacement with the Al+3 or Ca+2 ions in the matrix. As the concentration of metal cations in the matrix surrounding the glass particles decreases, the dissolution rate increases. Consequently, the dislocation of the glass particles and the ledges formed by the undissolved glass particles causes an increase in surface roughness [³⁰]. The increased surface roughness of the FIX group in the present study could be attributed to this state. Giomers are hybrid materials, having a resin matrix and pre-reacted glass filler (PRG) [³¹]. Citric acid-containing PLDs could degrade the giomer’s surface due to the greater susceptibility of fluorosilicate glass fillers to degradation by weak acids. Furthermore, the giomer’s larger average particle sizes may be responsible for the rougher surface profile, which supports the results of this study [³²].

The Ventolin syrup, which contains salbutamol sulfate and citric acid, significantly increased the surface roughness of the restorative materials in this study. The erosive potential of these two components is well-documented, and they are reported to hurt the surface texture of restorative materials [³³]. In a similar study, Aktaş et al. [³⁴] reported that certain dietary pediatric supplements with low pH and high acid content significantly increased surface roughness in both resin composites and glass ionomer restoratives. Their study demonstrated that repeated exposure to acidic pediatric liquids altered the surface topography of materials, especially those based on glass ionomer, which is in accordance with our findings on the erosive effect of Ventolin on surface texture.

Low-pH beverages and drugs cause erosion and dissolution of the surfaces of restorative materials, reducing surface hardness [³⁵]. The Aerius, Atarax, Keppra, and Ventolin drugs significantly decreased the microhardness of restorative materials in this study. Valera et al. [³⁶] highlighted the erosive potential of pediatric medications on restorative materials, finding that acidic pediatric drugs could reduce the mechanical properties of materials, leading to a decrease in microhardness and surface integrity. This supports our findings, which show that the microhardness of the restorative materials decreased significantly after immersion in various PLDs, particularly those with low pH values, such as Aerius, Atarax, and Ventolin. The microhardness values of the tested materials were significantly reduced after immersion in the drugs, except for Admira Fusion and Activa in this study. This result agrees with a previous study, which found that Admira Fusion did not show a significant loss of microhardness after immersion in soft drinks [³⁷]. All the materials tested can be considered biphasic. Hydrolytic degradation of the matrix-filler interface in acidic solutions produces disintegration and, eventually, loss of the filler particles. If the polymer matrix and the filler bond are broken, a material's hardness value will be affected [³⁸]. The fact that the microhardness of the restorative material depends on its type, composition, and tendency to deteriorate over time, as well as the variation in ingredients and erosion potential of PLDs, makes it challenging to interpret the results of such a study. For example, pH values for Aerius, Atarax, Ferrosanol B, Keppra, and Ventolin were 4.75, 1.33, 1.65, 4.96, and 2.58, respectively. In line with our results, Santos et al. [³⁹] demonstrated that long-term exposure to liquid pediatric medicines with low pH led to considerable erosion and mineral loss on the enamel surface of permanent teeth. However, the obtained microhardness values of the materials do not fully reflect their relationship with the pH of PLDs. This result is not entirely surprising because the erosive potential of drugs depends not only on pH but also on titratable acidity and the relative strength of the acid. Furthermore, the pH values of all drugs are at or below the range of 5.5-4, which is reported to be cariogenic [⁴⁰].

This may shed light on the surface softening detected in most tested materials. When subjected to conditioning in low pH acids, any chemical softening of restorative materials would adversely affect their clinical durability under occlusal load. Therefore, care should be taken when selecting restorative materials for patients who regularly use low-pH PLDs.

Under clinical conditions, saliva preserves the tooth surface and the restoration by diluting PLDs, thus minimizing the effect of PLDs. The in vitro study design has a limitation in that it does not fully reflect clinical conditions. To characterize the precise changes in aesthetic and physical properties of restorative materials, further studies that simulate oral conditions are necessary.

Conclusion

Pediatric liquid drugs affected the color stability and surface properties of dental restorative materials. Ferrosanol B could enhance the staining of materials, and the Equia Forte and Fuji II materials may show less color stability against PLDs. Ventolin could disrupt the surface roughness of materials, and exposure to PLDs could increase the surface roughness of Fuji II and Beautifil II. Pediatric liquid drugs could cause a significant reduction in the microhardness of materials.

Financial Support

• The study was supported by the Scientific Research Project Coordination Unit of Gaziantep University (DHF.UT.19.09).

Data Availability

The data used to support the findings of this study can be made available upon request to the corresponding author.

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Edited by

• Academic Editor:
  Alessandro Leite Cavalcanti

Publication Dates

• Publication in this collection
  23 Feb 2026
• Date of issue
  2026

History

• Received
  19 Feb 2025
• Reviewed
  05 May 2025
• Accepted
  08 July 2025