Medical

Communication

Biosci. Biotech. Res. Comm. 10(3): 354-358 (2017)

Effect of heptane food simulating liquid on surface

microhardness of 4 composites (Filtek Z250, Aelite,

Filtek Z350 and Clear l ST)

Niusha Golbari

, Morad Sadaghiani

*, Anahit Afrasiabi

, Mahdi Allahdadi

, Elmira Najafrad

and Ehsan Sadeghi Ziaratgahi

DDS. Post Graduate Student of Restorative Dentistry Department, Dental School, Shahid Beheshti University

of Medical Sciences, Tehran, Iran

Department of Restorative Dentistry, Islamic Azad University, Dental Branch, Tehran, Iran

DDS. Post Graduate Student of Restorative Dentistry Department, Dental School, Shahid Beheshti University

of Medical Sciences, Tehran, Iran

DDS. Post Graduate Student of Restorative Dentistry Department, Dental School, Shahid Beheshti University

of Medical Sciences, Tehran, Iran

DDS. Post Graduate Student of Restorative Dentistry Department, Dental School, Hamadan University of

Medical Sciences, Tehran, Iran

DDS. Post Graduate Student of Restorative Dentistry Department, Dental School, Shahid Beheshti University

of Medical Sciences, Tehran, Iran

ABSTRACT

Resin based composites are became more and more popular in restorative dentistry, particularly because of their

esthetic aspects. Decreasing the microhardness of dental restorative composites after curing in oral environment can

in uence their clinical durability. The aim of the current study was to determine effect of food simulating liquids 50%

heptane on surface microhardness of Z250 microhybrid, Aelite nano lled Z350 and Clear l nanohybrid composites.

20 specimens of each composite were prepared in a prefabricated mold with 5 diameter and 2 mm depth. All the

specimens composite were stored in distilled water, immediately after curing for 24 hours as the control group. Then

the specimens were taken out of the solution and washed, dried and then surface microhardness of specimens was

evaluated by the microhardness device based on Vickers. These specimens were divided into two groups randomly;

354

ARTICLE INFORMATION:

*Corresponding Author: Morad_Sadaghiani@yahoo.com

Received 23

July, 2017

Accepted after revision 28

Sep, 2017

BBRC Print ISSN: 0974-6455

Online ISSN: 2321-4007 CODEN: USA BBRCBA

Thomson Reuters ISI ESC and Crossref Indexed Journal

NAAS Journal Score 2017: 4.31 Cosmos IF: 4.006

reserved.

Online Contents Available at: http//www.bbrc.in/

DOI: 10.21786/bbrc/10.3/3

Niusha Golbari et al.

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EFFECT OF HEPTANE FOOD SIMULATING LIQUID ON SURFACE MICROHARDNESS OF 4 COMPOSITES 355

each of them was immersed in one of the following solutions distilled water, 50% heptane for 7 days at 37 ºC. After

one week conditioning period microhardness testing was carried out. The data were analyzed by 2way ANOVA and

Tucky HSD test. According to the results, there were signi cant differences on the initial microhardness of all com-

posites in water (p<0.05). Microhardness of the Z250 was higher than the other groups in water and heptane (p<0.05).

A signi cant decrease observed on the secondary microhardness of the Aelite and Clear l composites in heptane

compared to the  rst time (p<0.05). The Clear l had higher decrease on microhardness in water and heptane com-

pared to the other composites (p<0.05). The microhardness of composite resin materials used in this study in uenced

after immersion in Heptane food simulation solution and distilled water. The effect of heptane on change in surface

microhardness is material dependent.

KEY WORDS: COMPOSITE,NANOHYBRID, MICROHYBRID,NANOFILL, HEPTANE, FOOD SIMULATING

INTRODUCTION

The administration of resin-based restorative materials

in dentistry has increased recently because of their good

aesthetic appearance, improvements in formulations,

ease of handling, and ability to establish a bond to dental

hard tissues. The mechanical property of the dental com-

posites depends on the  ller particles and particle size.

Recent advancements on the organic matrix and inor-

ganic  llers have led to the development of new materi-

als with reduced particle size and increased  ller loading

which improved mechanical properties and aesthetics on

the current composite resin materials.Restorative materi-

als are required to have long-term continuousness while

the oral cavity is a complex aqueous environment and

restorative material contacts with saliva, (Catelan et al.

2010, Hengtrakool et al. 2011, Erdemir et al. 2013 George

and Kavyashree 2017).

Also, low pH due to acidic foods and drinks may

in uence the mechanical and physical characteristics of

the materials (Miranda et al. 2011). Physical character-

istics of restorative materials are an important concern

when determining suitable restorative materials because

they strongly in uence the clinical longevity of restora-

tions (Seifert et al. 2011). In clinical environment, micro-

hardness of materials decrease might contribute to its

deterioration. Under in vivo conditions, composite resin

materials may be exposed either discontinuously or con-

tinually to chemical agents found in saliva, food and

beverages (Topcu et al. 2010). In the short- or long-term,

these conditions have adverse effect on its physical and

chemical structure (Valinoti et al. 2008). The material’s

microhardness is one of the most important properties,

which correlates with resistance to intra-oral softening,

compressive strength and degree of conversion (Volta-

relli et al. 2010). A low surface microhardness value is

largely related to inadequate wear resistance and pro-

clivity to scratching, which can compromise fatigue

strength and lead to failure of the restoration (Erdemir

et al. 2013). So, the aim of the current study was to

determine effect of food simulating liquids 50% heptane

on surface microhardness of Z250 microhybrid, Aelite

nano lled Z350 and Clear l nanohybrid composites

MATERIAL AND METHODS

In this experimental in vitro study 4 composite types

were used (n=10). The composites allocated in stainless

steel (5mm diamater×2mm thickness). A smooth plate

put on the composite and the produced collected at 40 s

by SDS Kerr (1000mW/cm

) and polymerized (2×2) and

polished using aluminum oxide (3M ESPE) by spraying

the water. Then samples stored in distilled water 37ºC

for 24 h. Then microhardness of the samples determined

using Intender (6100 Vickers, USA).

COMPOSITES

The information of the composites used in the study

was Filtek z250 Micro hybrid ( ller weight 82%,  ller

volume 60%) Zirconia silica (0.6μm) Bis-EMA, UDMA

Bis-GMA. The Filtek Z350 was Nano lled ( ller weight

78.5%,  ller volume 59.5%) Zro2/sio2 nanocluster, Sio2

nano ller (5-20nm) Bis-GMA Bis-EMA UDMA TEG-

DMA. The Aelite was Nano lled ( ller weight 73%,  ller

volume 54%) Glass frit Amouphous silica (0.04-5μm)

Exhoxylated Bisphenol A Dimethacrylate TEGDMA.

The Clear lMajesty ES-2 was Nanohybrid ( ller weight

93%,  ller volume 81%) Silanatedbarium glass  ller

Pre-polymerized organic  ller (0.04-1μm) hydrophobic

aromatic dimethacyilate TEG-DMA Bis-GMA. The 50 gr

force for 15 s is done using Intender on 3 points in each

sample. Then the microhardness of the samples deter-

mined. The 10 samples allocated into the heptane and 10

in distilled water for 7 days. After one week condition-

ing period microhardness testing was carried out.

STATISTICAL ANALYSIS

The data were analyzed by 2way ANOVA and Tucky

HSD test using SPSS 16.0 for Windows (SPSS, Inc., Chi-

cago, IL, USA). P< 0.05 was considered as signi cant

differences between treatments.

Niusha Golbari et al.

356 EFFECT OF HEPTANE FOOD SIMULATING LIQUID ON SURFACE MICROHARDNESS OF 4 COMPOSITES BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

RESULTS AND DISCUSSION

According to the results, there were signi cant differ-

ences on the initial microhardness of all composites in

water (p < 0.05). Microhardness of the Z250 was higher

than the other groups in water and heptane (p < 0.05).

No signi cant difference observed on primary micro-

hardness of Aelite and Clear l (p > 0.05). A signi cant

decrease observed on the secondary microhardness of

the Aelite and Clear l composites in heptane compared

to the  rst time (p < 0.05). The microhardness of Clear l

signi cantly decreased compard to the other composites

in water and heptane conditions.

As seen in table 2, a signi cant differences observed

between primary and secondary microhardness of

the Z350 (65.30±6.19 and 75.84±4.25), 75.84±4.25

(50.88±7.47 and 39.87±5.07), Z250 (73.69±3.69 and

85.22±9.33) and Clear l (43.66±4.99 and 35.47±4.61).

As seen in table 3, signi cant difference was observed

on microhardness of Aelite (0.006) and Clear l (0.0001)

stored in heptane.

The primary and secondary microhardness of materi-

als is presented in table 4.

DISCUSSION

During consumption of food or drink contacts teeth or

restoration surfaces for only a short time before it is

washed away by saliva. Usually contact of teeth with

acidic food or drink for a prolonged period of time

and the situation did not account for the role of saliva

(Erdemir et al. 2013). As observed in the current study,

surface microhardness of Z250 was higher than the other

groups. After 24 hours distilled water had signi cant

effect on all the specimens. After 7days distilled water

had signi cant effect on all groups however, Heptane

had signi cant effect on Aelite and Clear l specimens.

According to analyses after both 24 hours and 7 days

Z250 and Z30 specimens showed increase in micro-

hardness while Aelite and Clear l showed signi cant

decrease in microhardness. Clear l presented the low-

est microhardness values. Distilled water was selected

instead of arti cial saliva to simulate the aching effect

of saliva because the arti cial saliva storage medium is

not considered to be a more clinically relevant environ-

ment (Erdemir et al. 2013).

The surface microhardness index of all restorative

materials after a week of storage in distilled water was

higher than the baseline surface microhardness val-

Table 1. The microhardness of the different composited

composite stored in distilled water or heptane

Composite Food

suspension

Primary

microhardness

Secondary

microhardness

Z350

distilled

water

65.3000 75.8450

Heptane 63.8390 67.3380

Aelite

distilled

water

73.6970 85.2210

Heptane 77.3370 82.7360

Z250

distilled

water

50.8810 39.8760

Heptane 50.8720 39.8550

Clear l

distilled

water

43.6690 35.4780

Heptane 43.4300 33.5460

Table 2. the primary and secondary microhardness of

composite stored in distilled water

Composite Primary

distilled water

Secondary

distilled water

P value

Z350 65.30±6.19 75.84±4.25 0.0001

75.84±4.25 50.88±7.47 39.87±5.07 0.015

Z250 73.69±3.69 85.22±9.33 0.0001

Clear l 43.66±4.99 35.47±4.61 0.013

Table 3. the primary and secondary microhardness

of composite stored in heptane

Composite

Primary

heptane

Secondary

heptane P value

Z350 63.83±3.55 67.33±5.95 0.226

Aelite 50.87±6.41 39.85±6.90 0.006

Z250 77.33±6.27 82.73±3.68 0.064

Clear l 43.43±4.46 33.54±2.62 0.0001

Table 4. the primary and secondary microhardness of

materials

Compared materials t-Test P value

Z350 & Distilled water

(primary & secondary)

-10.54±1.33 -7.906 0.001

Z350 & Heptane

(primary & secondary)

-11.52±6.86 -5.312 0.226

Aelite & Distilled water

(primary & secondary)

11.00±3.67 2.991 0.015

Aelite & Heptane

(primary & secondary)

11.01±3.083 3.573 0.006

Z250 & Distilled water

(primary & secondary)

-9.09±8.90 -3.231 0.001

Z250 & Heptane

(primary & secondary)

-9.55±10.71 -2.820 0.064

Clear l & Distilled water

(primary & secondary)

8.19±2.66 3.072 0.013

Clear l &Heptane

(primary & secondary)

9.88±1.35 7.280 0.001

Niusha Golbari et al.

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS EFFECT OF HEPTANE FOOD SIMULATING LIQUID ON SURFACE MICROHARDNESS OF 4 COMPOSITES 357

ues. This could possibly be explained by the ampli-

 ed monomer conversion and additional post-curing

cross-linking reactions in the resin phase over the time.

Compoglass F, Filtek Z250, Filtek Supreme and Premise

specimens stored in distilled water had lower surface

microhardness reductions compared to the specimens

immersed in sports and energy drinks (Erdemir et al.

2013). In a study using Meliodent, FuturaGen and hard

GC reline.

Rajaee et al. (2014) reported heptane conditioning

decreased the  exural strength of Meliodent and Futur-

aGen and microhardness of FuturaGen. Ethanol solution

had the most adverse effect on the microhardness and

 exural strength of the tested resin materials (Rajaee

et al. 2014). Takahashi et al. (1998) reported that water

immersion had different effects on the  exural strength

and microhardness of different denture base and reline

resin materials. They concluded that the results could

be due to the fact that the intrinsic strength of the

resin and the amount of water sorption in the system

in uences the mechanical strength of water absorbed

acrylic resins. It is reported two days of immersion in

the water lead to a reduction in the microhardness of

the resin samples. As mentioned, water absorption and

continuation of the acrylic polymerization process is

time-dependent and diffusion-controlled Azevedo et

al. (2005). Organic solutions may damage the resin

matrix (heptane and aqueous ethanol solution). On the

other hand, water and citric acids can damage organic

 llers. Therefore organic solutions could decrease  ex-

ural strength and microhardness of dental resins (Yesi-

lyurt et al. 2009).

In a study, Yaniko

˘lu et al. (2009) determined the

surface microhardness of  lled (Estelite), nano l (Ælite),

un lled (Valux Plus), hybrid (Tetric ceram) and Ormocer-

based (Admira) composite resins in tea, coffee, Turk-

ish coffee, mouthwash, cola, and distilled water. Based

on their report the microhardness values of composite

materials were statistically different in different immer-

sion solutions. The acidity may change the polymeric

matrixes of composite resin affecting dimethacrylate

monomer present in their compositions (Al-Samadani,

2013). A previous study suggested that, by lowering the

solutions’ pH, there is production of methacrylic acid

that results in the sorption and hygroscopic expansion

as a consequence of enzymatic hydrolysis and biodeg-

radation (Sripetchdanond and Leevailoj, 2014). It was

observed that sodium  uoride containing mouth rinses

also reduce the surface microhardness (Sripetchdanond

and Leevailoj, 2014).

In a recent study, George et al (2017) on effect of four

mouth rinses on microhardness of resin composite (Filtek™

P60) material (3M ESPE St. Paul, MN, USA) reported all the

mouth rinses showed reduction in surface microhardness

of the esthetic restorative material. Yesilyurt et al. (2009)

reported microhardness of silorane-based composite was

not in uenced by ethanol signi cantly, which could be

due to the hydrophobicity of the resin matrix. Except for

Bis-EMA, all other molecules (Bis-GMA, UDMA, and TEG-

DMA) have hydroxyl groups, which promote water sorp-

tion. As for silorane-based composite, it has 3,4-epox-

ycyclohexyl-cyclopolymethylsiloxane. In conclusion, the

microhardness of composite resin materials used in this

study in uenced by food simulation solutions. The effect

of heptane on change in surface microhardness is material

dependent.

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