Journal of Indian Society of Pedodontics and Preventive Dentistry
Journal of Indian Society of Pedodontics and Preventive Dentistry
                                                   Official journal of the Indian Society of Pedodontics and Preventive Dentistry                           
Year : 2019  |  Volume : 37  |  Issue : 2  |  Page : 151--156

Effect of different pediatric drug formulations on color stability of composite, zirconia-reinforced glass ionomer cement, and glass ionomer cement

Yogesh J Kale, Apeksha Vikram Nalwade, Prasanna Trambakrao Dahake, Mahesh V Dadpe, Shrikant B Kendre 
 Department of Paedodontics and Preventive Dentistry, MIDSR Dental College and Hospital, Latur, Maharashtra, India

Correspondence Address:
Dr. Apeksha Vikram Nalwade
Department of Paedodontics and Preventive Dentistry, MIDSR Dental College and Hospital, Latur, Maharashtra


Introduction: Various liquid drug formulations are prescribed to the children. Frequent use of these drugs can result in staining of dental restorations, affecting their longevity and durability. Aim: This study aims to evaluate the effect of different pediatric drug formulations on color stability of various esthetic restorative materials. Materials and Methods: Three different restorative materials namely composite resin, Zirconomer Improved, and conventional glass ionomer cement (GIC) were used to prepare total 120 (40 from each) disc-shaped specimens having dimensions 12 mm × 1.5 mm. The specimens of each material were divided into five experimental groups (n = 8) through stratified random sampling technique and were immersed in five different liquid medications: Group 1 – amoxicillin + clavulanic acid, Group 2 – metronidazole, Group 3 – cephalexin, Group 4 – ibuprofen, and Group 5 – ibuprofen + paracetamol. All samples were agitated for 2 min and cycle was repeated eight hourly for 1 week with intermittent pH cycling to simulate conditions similar to the oral environment. Color stability of all specimens was evaluated using spectrophotometer. One-way ANOVA and Tukey's post hoc HSD test were used for statistical analysis.Results: Results obtained revealed that Δ E* (color difference) elevation was significantly low with GIC (P < 0.001) and high with composite for all five groups. Amoxicillin + clavulanic acid and metronidazole group showed highest color stainability among all groups. Conclusion: GIC showed better color stability with all drug formulations. The highest color alteration was observed in composite resin, whereas zirconia reinforced GIC showed color stability lesser than GIC but better than composite.

How to cite this article:
Kale YJ, Nalwade AV, Dahake PT, Dadpe MV, Kendre SB. Effect of different pediatric drug formulations on color stability of composite, zirconia-reinforced glass ionomer cement, and glass ionomer cement.J Indian Soc Pedod Prev Dent 2019;37:151-156

How to cite this URL:
Kale YJ, Nalwade AV, Dahake PT, Dadpe MV, Kendre SB. Effect of different pediatric drug formulations on color stability of composite, zirconia-reinforced glass ionomer cement, and glass ionomer cement. J Indian Soc Pedod Prev Dent [serial online] 2019 [cited 2019 Oct 18 ];37:151-156
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Full Text


Esthetic appearance is considered as a prime factor for social acceptance as well as professional success.[1] In pediatric dentistry, number of esthetic restorative materials such as composite resins, glass ionomers, compomers, and zirconia-reinforced glass ionomer cements (GICs) are used with comparable results. These materials are used for restoring decayed esthetic zones of posterior as well as anterior teeth, helping improve disfigured teeth. However, longevity and acceptability of such restorations are directly proportional to the color stability of the restorative materials used.[2] On the other hand, various extrinsic and intrinsic stains cause discoloration of restorations rendering high failure rate. Extrinsic discolorations can be attributed to insufficient polymerization, frequent consumption of food and beverages as well as drug formulations containing coloring agents/additives.[3] Drug formulations in the form of syrups or suspensions are administered usually to young children facing acute and/or chronic disease conditions due to lower compliance to other forms of medications.[4] The ingredients used in these liquid formulations include sugars, acids, buffering agents, permitted coloring agents in the form of oil and/or water-soluble agents.[5] The presence of sucrose in such formulations facilitate drop of pH in dental plaque and also acts as substrate for fermentation of oral microbiota contributing to dental caries. Low endogenous pH and high titratable acidity of these medicines may pose unfavorable effects such as erosion, intrinsic/extrinsic staining of tooth surfaces, and dental restorations.[6] Besides this, long-term contact of such liquid formulations with primary teeth may lead to reduced enamel hardness, altered surface, and surface degradation of restorations.[7]

Aim of the study

The aim of this study was to evaluate the effect of different pediatric drug formulations on color stability of three esthetic restorative materials, i.e., composite resin, zirconia-reinforced GIC (Zirconomer Improved), and GIC.

Hypothesis of the study

Pediatric drug formulations affect the color stability of dental restorations.

 Materials and Methods

The presentin vitro experimental study was carried out at the department of pedodontics and preventive dentistry after gaining clearance from institutional ethical committee, vide letter no MIDSR/V/PG/5231/966/A/16.

Specimen preparation

In this study, we used three different restorative materials namely composite resin (Tetric N-Ceram, Ivoclar Vivadent, Liechtenstein), zirconia-reinforced GIC (Zirconomer Improved SHOFU INC, UK), and GIC (Gold Label, Universal Restorative 2, GC Corporation Tokyo, Japan). From each material, we prepared 40 disc-shaped specimens, having dimensions 12 mm × 1.5 mm using brass molds. For each specimen, the material was mixed as per manufacturer's instructions and adapted into the brass mold. During preparation of specimens for composite resin, for each specimen, the material was placed in the brass mold and covered with mylar strip followed by light curing for 20 s using LED light curing unit (Uranium L/C, Dentmark). During the preparation of specimens for zirconia-reinforced GIC, for each specimen, petroleum jelly was applied all over the surfaces of brass mold. Then, the mold was based on glass slab covered with mylar strip. Standard powder-liquid ratio (3.6/1.0 g) was dispensed on mixing pad followed by the division of powder into two equal increments. The powder was mixed gradually into liquid incrementally to achieve appropriate consistency of mixed material. The material was adapted into the mold over which another mylar strip was placed and held in place till the material sets.[8] While preparing specimens for GIC, for each specimen, petroleum jelly was applied to all the surfaces of the mold and mold was placed on glass slab covered with mylar strip. Standard powder to liquid ratio (2.7/1.0 g) was dispensed on mixing pad and was mixed gradually for 15–20 s until appropriate consistency was achieved.[9] The mold was slightly overfilled to minimize air entrapment followed by placing a mylar strip with glass slab over it with slight pressure to remove excess material and obtain a uniformly smooth specimen. All specimens were stored in double deionized distilled water till further use.

Subgrouping of the specimens

A total of 120 specimens were prepared from three restorative materials (40 from each). Each group was further divided into five subgroups (n = 8) according to the pediatric drug formulations to be tested as Group 1 – amoxicillin + clavulanic acid (AMOXYCLAV DS; Abbott Healthcare Pvt. Ltd., India), Group 2 – metronidazole (Metrogyl; J. B. Chemicals and Pharmaceuticals Ltd., India), Group 3 – cephalexin (Phexin REDISYP; GlaxoSmithKline Pharmaceuticals Limited, India), Group 4 – ibuprofen (Ibugesic; Cipla Ltd., India), and Group 5 – ibuprofen + paracetamol (Ibugesic Plus; Golden Cross Pharma Pvt. Ltd., India) through stratified random sampling technique.

Baseline color assessment

All the specimens were then rinsed and dried with filter paper, and baseline color values were recorded using spectrophotometer (Spectrascan 5100+ PC/QC/020). Color evaluation was performed with color parameters based on the average daylight (D65).

Before the measurements, spectrophotometer was calibrated with its own special calibration tool and positioned in the center of each specimen. The color of specimens was assessed according to the Commission International de I Eclairege L*a*b* (CIELAB) color space using digital image analysis method. The CIELAB system is a chromatic value color space that measures chroma and value in three coordinates:

L* represents brightness or lightness (value)a * and b * serve as numeric correlates both for hue and chroma.

The a * and b * values represent position on a red/green and yellow/blue axis, respectively.[10]

The magnitude of the color difference (ΔL*) perceived between two objects is thus calculated. The calculation of ΔL* (color difference before and after immersion) was done using the following formula:[11]

ΔE (L * a * b*) = ([ΔL*]2+ [Δa*]2+ [Δb*]2) 1/2

In which ΔL* is the difference between the L* valuesΔa* is difference between the a* valuesΔb* is difference between the b* values.

Each specimen was assessed for color measurements in triplicates, and the average was recorded.

pH cycling

All specimens were subjected to pH-cycling by daily immersion in demineralizing solution for 8 h and in remineralizing solution for 16 h. The demineralizing solution was prepared using calcium chloride, ammonium phosphate, and acetic acid and was adjusted to pH 4.8 whereas remineralizing solution was prepared using CaCl2, NaH2 PO4, and KCl adjusted to pH 7. pH cycling was performed to simulate conditions of oral environment.[10]

Immersion cycles and color change measurement

A volume of 15 mL of each pediatric liquid drug formulation was dispensed in glass beaker. Specimens from each group were removed from pH cycling solutions and immersed in respective liquid medications followed by agitation for 2 min at every 8 h for 1 week. After 1 week of cumulative immersion cycle, specimens were rinsed with double deionized distilled water for 5 s, gently brushed with soft toothbrush for 15 s and dried gently with clean tissue paper. At this point, color measurements were recorded again with the same method and resistance to staining expressed in the unit ΔE* was calculated by using the above-mentioned formula.

Statistical methods

The data obtained with regard to chromatic value space which measures the value of chroma were subjected to statistical analyses. Statistical analysis was performed with SPSS version 22.0 statistical package for MS Window (SPSS Inc. Chicago, IL, USA). Intergroup mean and standard deviations were analyzed using one-way ANOVA and statistical significance was analyzed using Tukey's post hoc HSD test.


Means and standard deviations of ΔE were calculated. In composite resin, the highest ΔE value was recorded in Group 2 (6.99713 ± 0.563) followed by Group 1 (6.16525 ± 0.837) whereas the lowest value of ΔE was recorded in Group 3 (4.11 ± 0.548) with P < 0.0001 and F = 17.898. In Zirconomer Improved, highest color changes were observed in Group 2 (5.800 ± 0.607) followed by Group 3 (5.450 ± 1.042) and least color change was observed in Group 1 (4.368 ± 0.920) with P < 0.006 and F = 4.280. In GIC, the highest value of ΔE was recorded in Group 1 (5.870 ± 0.655) whereas least in Group 4 (2.126 ± 0.841) with P < 0.0001 and F = 31.120 [Table 1] and [Graph 1].{Table 1}[INLINE:1]

In Group 1, when the composite resin was compared with Zirconomer Improved, high statistical significance (P < 0.001) was observed in relation to ΔE (magnitude of color difference), whereas there was no significant difference observed between composite resin and GIC. When Zirconomer Improved was compared against GIC, statistically significant difference was noted (P < 0.004). In Group 2, high statistical significance was noted between all three restorative materials (P < 0.001). In Group 3, when composite resin was compared with Zirconomer Improved, statistically significant difference (P < 0.008) was observed whereas ΔE values in composite resin and GIC were statically not significant. When Zirconomer Improved was compared with GIC, statistically high significance was noted (P < 0.0001). In Group 4, no statistically significant difference was found when composite resin was compared with Zirconomer Improved whereas statistically high significant difference (P < 0.0001) was found when composite resin and Zirconomer Improved was compared against GIC. In Group 5, no significant difference was found when composite resin was compared with Zirconomer Improved whereas statistically high significant difference (P < 0.0001) was found when composite resin was compared with GIC. When Zirconomer Improved was compared with GIC, statistically significant difference (P < 0.008) was found [Table 2].{Table 2}


Dental restorations are constantly exposed to multiple oral environmental challenges such as variations in temperature and pH. This results in series of extrinsic and intrinsic changes at surface or within the body of the material that alter their physical, mechanical, chemical as well as esthetic properties.[3] One of which is color stability influencing the longevity and durability of the restorations. Discoloration due to intrinsic and extrinsic factors includes adsorption of coloring agent on the surface and absorption within subsurface layer making it prone for replacement consuming money and time of patients as well as dental practitioners.[12] The color stability of restorative material is accredited to multiple factors including type of matrix of restorative material, particle size, filler content, filler type, polymerization depth, mode of polymerization as well as contact with coloring agents. It is also directly related to hydrophilic property of the material.[13]

In the present study, we aimed to evaluate the effect of five different pediatric drug formulations, i.e., three antibiotics and two analgesics on color stability of composite resin, zirconia-reinforced GIC and conventional GIC. Extensive search of literature has revealed that very few studies have been conducted on color stability of zirconia-reinforced GIC. To avoid subjective bias associated with color sensitivity in human investigators, we used spectrophotometer, which has several other advantages such as repeatability, sensitivity, and objectivity. In our study, the most prominent color alteration was seen in composite resin with metronidazole group and least in GIC with ibuprofen group. We found significant color changes in composite resin as compared to the other two materials in all the five groups. This finding was in agreement to the study done by Tüzüner et al. in 2017 which reported that the composite exhibits significant discoloration values when exposed to commonly used pediatric drugs.[11] Probable reason behind discoloration of composite resin can be water absorption induced weaker bond between resin matrix and filler particles leading to microcracks or interfacial gaps between matrix-filler interface or due to chemical changes in initiator-activator system and water absorption of the monomers in composites enabling stain penetration and discoloration.[14] Rueggeberg andCraig 1988 suggested that silanization of filler particles used in resin-based composite also plays an important role in discoloration. The fact behind is silane is hydrophilic and leads to high water absorption.[15] Therefore, high staining values of composite resin (Tetric – N Ceram) may attribute to high proportion of silane present in the structure of the material. As a result, it can be stated that composite resins with high amount of resin matrix, low concentration, and larger size filler particles have more tendency toward discoloration.[16]

In this study, conventional GIC (Gold Label, Universal Restorative 2, Gc Corporation Tokyo, Japan) was found to be more resistant to color changes which is in agreement to the results given by Tüzüner et al. in 2017.[11] Higher resistance of GIC to color alterations can be attributed to two factors. First, inherent property of restorative material and secondly, staining capacity of coloring agent, particularly particle size of coloring agent as well as hydrophilic or hydrophobic nature of the same.[17] As GIC contains more glass filler particles in the core of the set material, it does not allow absorption of water into the bulk of the material; however, some water may get absorbed onto and/or through the surface and subsurface organic matrix.[10] On the other hand, Bagheri et al. in 2005 stated that higher water content of conventional GIC allows lesser water absorption making it less susceptible to color changes.[13]

In the present study, color stability of Zirconomer Improved was found to be in between composite resin and GIC respectively among all the five groups. Zirconia-reinforced GIC (Zirconomer Improved, SHOFU INC, Universal Shade, UK) was introduced with the purpose of enhancing mechanical properties of conventional GIC as well as to overcome drawbacks of previously used tooth colored esthetic restorative materials.[8] It contains mainly zirconium oxide, glass powder, tartaric acid, polyacrylic acid, and deionized water as its liquid.[18] The main component of zirconia-reinforced GIC (Zirconomer Improved) is nano-sized zirconia filler particles ranging from 96.5% to 98.5%. These filler particles are proclaimed to impart high level of translucency and achieve closer match to natural tooth color. However, increased susceptibility of “Zirconomer Improved” in terms of color change may be associated with addition of variable sized inert zirconia particles and translucency of the same. The presence of inert zirconia filler particles and difference between refractive index of filler particles and reacted glass particles may also contribute to color changes as observed in our study. Prabhakar et al. in 2015, reported that conventional GIC was much better as compared to ZrO2 infused GIC in terms of better color stability, color match, surface texture, and marginal adaptation.[19] At present, very limited literature is available related to color stability of Zirconomer Improved.

The amoxicillin with or without the association of clavulanate, metronidazole, ibuprofen, cephalexin, and paracetamol are the medicines widely prescribed to children for the treatment of different infections. However, prolonged use of these liquid medications may pose a threat to oral health causing effects such as dental caries, erosion, and intrinsic/extrinsic staining of tooth surfaces/restorations.[6] The properties of oral antibiotics and analgesics that are responsible for these unfavorable effects are low pH, high titratable acidity, high sucrose concentration, and viscosity. Besides low pH and high titratable acidity, frequent and long-term usage of such medications may lead to ionic dissolution from the hydroxyapatite crystals and ultimately initiation of carious lesions.[20] Thus, it is essential to draw attention to the real impact of the use of liquid medications, either antibiotics or analgesics in the daily life of children.

In the present study, among all the tested liquid medications, Group 2, i.e., metronidazole (6.997 ± 0.563) showed highest staining ability followed by Group 1, i.e., amoxicillin + clavulanic acid (6.165 ± 0.837) and least staining was observed in Group IV, i.e., ibuprofen (2.126 ± 0.841). The pH of metronidazole syrup is around 5.6, and that of amoxicillin + clavulanic acid syrup is around 5.39.[19] The viscosity of amoxicillin + clavulanic syrup is around 1396.67 centipoises (cP) and metronidazole syrup is 1194.0 cP.[5],[21] As these liquid medications possess high viscosity, they tend to retain on the tooth surface for longer duration as well as have slow salivary clearance rate which lead to enamel erosion and further consequences.[22] The permitted coloring agents used in these liquid medications may be absorbed and adsorbed by the resinous materials affecting the color stability of these materials.[23] The sucrose percentage in both the medications is around 10% and 5%, respectively. These syrups are usually given in BD or TDS dosage to children. Especially, night dose has deleterious effect on the primary enamel and restorations as the salivary flow rate is diminished at night. As primary tooth enamel is less mineralized than that of permanent tooth enamel, it is prone to unfavorable effects such as dental caries, dental erosion, and staining of tooth surface/restoration due to frequent usage of these low pH and high sucrose containing liquid medications.[20] Hence, in children, judicious use of these liquid medications is advised.

Within the limitations of the present study, we would like to state that, the role of saliva, oral environment or oral clearance of liquid drug formulations simulated throughin vitro experimental conditions may not be adequate to mimic actual oral conditions. Therefore, further investigations need to be done on physical properties in detail.


Color sustainability of restorative materials is imperative for the success of the treatment. The selection of the appropriate restorative material is crucial which should meet adequate inherent characteristics such as dimensional stability, and color stability. Based on the results of the present study, it can be concluded that, though all the restorative materials showed staining when exposed to five different liquid medications, GIC seems most resistant to discoloration compared to Zirconomer Improved and composite resin. Recently introduced Zirconomer Improved showed better performance in terms of color stability compared to composite resin, but it was inferior compared to conventional GIC. Among tested liquid medications, metronidazole, and amoxicillin + clavulanic acid resulted in the highest staining ability with composite resin material whereas ibuprofen showed least staining ability with GIC.

The information regarding staining ability of commonly used pediatric liquid medications in combination with different restorative materials such as metronidazole-composite resin and amoxicillin + clavulanic acid-composite resin should be given to the pediatricians, pediatric dentists and parents too for alerting them to the risk of discoloration of the tooth surface/restorations. In addition, further studies need to be carried out within vivo study designs including commonly used liquid medications and restorative materials in children.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Abusunilli H, Avula JS, Kakarla P, Bandi S, Mallela GM, Vallabhaneni K. Colour stability of aesthetic restorative materials used in pediatric dentistry: Anin vitro study. J Indian Soc Pedod Prev Dent 2016;34:233-7.
2Shamszadeh S, Sheikh-Al-Eslamian SM, Hasani E, Abrandabadi AN, Panahandeh N. Color stability of the bulk-fill composite resins with different thickness in response to coffee/water immersion. Int J Dent 2016;2016:7186140.
3Llena C, Fernández S, Forner L. Color stability of nanohybrid resin-based composites, ormocers and compomers. Clin Oral Investig 2017;21:1071-7.
4Scatena C, Galafassi D, Gomes-Silva JM, Borsatto MC, Serra MC.In vitro erosive effect of pediatric medicines on deciduous tooth enamel. Braz Dent J 2014;25:22-7.
5Subramaniam P, Nandan N. Cariogenic potential of pediatric liquid medicaments – Anin vitro study. J Clin Pediatr Dent 2012;36:357-62.
6Topcu FT, Sahinkesen G, Yamanel K, Erdemir U, Oktay EA, Ersahan S, et al. Influence of different drinks on the colour stability of dental resin composites. Eur J Dent 2009;3:50-6.
7Nalwade Apeksha V, Kale Yogesh J, Dadpe Mahesh V, Dahake Prasanna T, Kendre Shrikant B. Effect of paediatric liquid medications on surface roughness of dental restorative materials. J Adv Med Dent Sci Res 2019;7:123-7.
8Zirconomer Improved Zirconia Reinforced Restorative. Available from: Brochure.pdf. [Last accessed on 2017 Oct 26].
9Glass Ionomer Cement. Available from: [Last accessed on 2017 Oct 09].
10Hotwani K, Thosar N, Baliga S. Comparativein vitro assessment of color stability of hybrid esthetic restorative materials against various children's beverages. J Conserv Dent 2014;17:70-4.
11Tüzüner T, Turgut S, Baygin O, Yilmaz N, Tuna EB, Ozen B, et al. Effects of different pediatric drugs on the color stability of various restorative materials applicable in pediatric dentistry. Biomed Res Int 2017;2017:9684193.
12Erdemir U, Yildiz E, Eren MM. Effects of sports drinks on color stability of nanofilled and microhybrid composites after long-term immersion. J Dent 2012;40 Suppl 2:e55-63.
13Bagheri R, Burrow MF, Tyas M. Influence of food-simulating solutions and surface finish on susceptibility to staining of aesthetic restorative materials. J Dent 2005;33:389-98.
14Özdaş DÖ, Kazak M, Çilingir A, Subaşı MG, Tiryaki M, Günal Ş, et al. Color stability of composites after short-term oral simulation: Anin vitro study. Open Dent J 2016;10:431-7.
15Rueggeberg FA, Craig RG. Correlation of parameters used to estimate monomer conversion in a light-cured composite. J Dent Res 1988;67:932-7.
16Oysaed H, Ruyter IE. Water sorption and filler characteristics of composites for use in posterior teeth. J Dent Res 1986;65:1315-8.
17Satou N, Khan AM, Matsumae I, Satou J, Shintani H.In vitro color change of composite-based resins. Dent Mater 1989;5:384-7.
18Chalissery VP, Marwah N, Almuhaiza M, AlZailai AM, Chalisserry EP, Bhandi SH, et al. Study of the mechanical properties of the novel zirconia-reinforced glass lonomer cement. J Contemp Dent Pract 2016;17:394-8.
19Prabhakar AR, Kalimireddy PL, Yavagal C, Sugandhan S. Assessment of the clinical performance of zirconia infused glass ionomer cement: Anin vivo study. Int J Oral Health Sci 2015;5:74-9.
20Mittal S, Singh BP, Sharma AK, Mittal K, Justa A, Vaid P. Surface changes of primary tooth enamel by commonly used paediatric liquid medicaments: A scanning electron microscope study. J Pediatr Dent 2017;5:14-20.
21Gupta M, Panda S. Cariogenic potential of the commonly prescribed pediatric liquid medicaments in Kingdom of Saudi Arabia: Anin vitro study. J Contemp Dent Pract 2017;18:307-11.
22Kahaliw W, Ashenef A. Comparative quality evaluation of some metronidazole tablets and metronidazole benzoate oral suspensions available in retail outlets of Addis Ababa, Ethiopia. Int J Pharm Sci Res 2013;4:1384-91.
23Shah V, Venkataraghavan K, Choudhary P, Trivedi K, Shah S, Bhandi S. Comparative evaluation of the four most commonly used pediatric liquid formulations in Ahmedabad city: Anin vitro study. World J Dent 2017;8:190-5.