Medical

Communication

Biosci. Biotech. Res. Comm. 10(3): 475-480 (2017)

Comparison of the effects of IPS e.max heat press layered

and feldspathic porcelain on natural enamel tooth wear

Hedaiat Moradpoor

, Marjan Mardanpour

, Farnoush Golmohamadi

and Sahar Raissi

Assistant Professor, Prosthodontics Department, Faculty of Dentistry Kermanshah University of Medical

Sciences, Iran

Faculty of Dentistry, Kermanshah University of Medical Science, Kermanshah, Iran

Assistant Professor, Prosthodontics Department, Faculty of Dentistry Kermanshah University of Medical

Sciences, Iran

ABSTRACT

In an ideal situation, the tooth wear of a restorative material should be similar to dental enamel. Currently, All-ceramic

restorations are widely used; But Enamel wear is among the main disadvantages of ceramic restorations. Thus, in this

study compared the Effect of IPS e.max heat press layered and Feldspathic Porcelain on natural enamel Tooth Wear.In this

study, 20 samples were prepared from normal human teeth. The natural teeth were photographed by a stereomicroscope in

a  xed position and the distance from the cusp tip to a reference point was measured. Next, 10 teeth opposed IPS e.max

heat press layered and the remaining 10 opposed Feldspathic Porcelain in a chewing simulator and subjected to 120,000

masticatory cycles. The teeth were photographed again and the greatest difference between the before and after values was

recorded. Finally data were analyzed by Independent samples T-test. The mean extent of wear on the restoration layered

IPS e.max heat press and Feldspathic Porcelain were not signi cant differences ( p-value= 0.118); although the average

wear in Feldspathic Porcelain was less than layered IPS e.max heat press. the distance from the cusp tip to a reference point

in layered IPS e.max heat Press was signi cantly difference between before and after intervention (p-value<0.001). Also,

the distance from the cusp tip to a reference point in FeldspathicPorcelain was signi cantly difference between before and

after intervention (p-value<0.001). According to the results obtained in vitro study, the mean extent of wear on the resto-

ration layered IPS e.max heat press and Feldspathic Porcelain were not signi cant differences. Also, it is recommended to

have a closer look at the factors involved in tooth enamel wear in future studies.

KEY WORDS: FELDSPATHIC PORCELAIN, IPS E.MAX HEAT PRESS LAYERED, ENAMEL TOOTH WEAR

475

ARTICLE INFORMATION:

*Corresponding Author: raissi_sahar@yahoo.com

Received 2

July, 2017

Accepted after revision 29

Sep, 2017

BBRC Print ISSN: 0974-6455

Online ISSN: 2321-4007 CODEN: USA BBRCBA

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NAAS Journal Score 2017: 4.31 Cosmos IF: 4.006

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Online Contents Available at:

http//www.bbrc.in/

DOI: 10.21786/bbrc/10.3/21

476 COMPARISON OF THE EFFECTS OF IPS E.MAX HEAT PRESS LAYERED AND FELDSPATHIC PORCELAIN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

Hedaiat Moradpoor et al.

INTRODUCTION

Replacement of missing teeth or repair a part of a tooth

has long been considered by dentists, Currently using a

variety of ceramic restorations has largely resolved this

problem; Ceramic restorations have advantages includ-

ing lack of fracture, lack of blanching and high strength

are also by considering the aesthetic, ease of use and

color similar to natural tooth using these restorations

have increased daily. These restorations due to the lack

of metal in their structure (metal component can cause

problems such as chemical toxicity, kerogen, change the

color of gums and creating allergic reactions to some

metals such as nickel) are preferred compared with

coated of metal - ceramic (Jung 2010) and Rosenstiel,

2015, Murillo-Gómez, 2017 and (Montazerian, 2017).

There are also disadvantages in addition to the top

bene ts of these restorations that the most important of

them is front tooth enamel erosion (Shillingburg, 2013).

Erosion is de ned as damage to the tooth surface or los-

ing volume of teeth by direct contact with the teeth or

other materials. In fact, erosion is a physiological phe-

nomenon that is happening naturally always mechani-

cally or chemically (DeGee, 1986). The sharp rise of den-

tal erosion can cause to loss of centric contacts, vertical

elevation change, Change in Functional paths during

chewing and fusion muscle fatigue (DeLong, 1989) and

(Gallegos, 1988). Dental restorations change the natu-

ral erosion rate of front teeth if have had different ero-

sion features (Sulong, 1990). So erosion between tooth

and its front restoration should be always considered

as important factor along with strength and beauty to

selecting restorative matter (Seghi, 1991).Considering

this, various methods have been tested to improve and

reduce the erosion of the front teeth in ceramicrestora-

tions; Among these methods, reinforced ceramics with

alumina oxide crystals, Lusaite, lithium DE silicate and

zirconia (Komine, 2004) and (Barath, 2003).

Given the importance of the front dental erosion by

ceramic restoration, in this study, two restorations of the

Feld spathic porcelain and layered IPS e.max heat press

ceramic were evaluated and compared in terms of the front

side tooth enamel. The reasons for choosing these two res-

torations can be reffered to improve the ceramic proper-

ties and porcelain bonding systems that has been caused

to beauty and good performance of feldspathic porcelain

(Vieira, 2004) and IPS e.max Press makers claim to improve

physical and translucency properties, lower surface hard-

ness low concentrations of crystalline phase and a smaller

sizes of crystals at different stages of cooking Empress 2

and revise in formulation of the this kind of ceramic to

obtaining high quality (Newsome 2014) and (Guess 2011).

Of course in laboratory studies that have been done in

this area, a signi cant difference has not been speci ed

in phase composition and the bending strength between

IPS e.max Press and Empress 2 (Guazzato, 2004) and

(Albakry 2003). IPS e.max Press in monolithic mode is

used for inlays, onlays, full coverage of crown... (Guess

2011). In times of short and medium term have shown in

reviewing these performances that IPS e.max Press res-

torations have good performance: Using this restoration

in onlays in the 3-year period, the ef ciency of 100%

(Guess 2009) and the crown in the 3-year period has

had the performance of 96.6% (Etman, 2008). Despite

this high performance, high erosion possibility of this

restoration on the tooth enamel can be considered as

one of the major disadvantages (Esquivel-Upshaw 2012).

Also, amount of natural tooth erosion against the lay-

ered IPS-emax heat press and feldspathic porcelain were

discussed due to lower researches and lack of consensus

on the abrasive effect of these ceramics and the need for

further studies in this area.

MATERIALS AND METHODS

This study was done as In vitro and in Reference Labo-

ratory and Research Center University of Medical Sci-

ences in Tehran. The study population was healthy teeth

recently extracted and without premolar decay of human

maxillary. Easy non-probability sampling method and

sample size were obtained from the results of previous

studies (Ahmadzadeh, 2014) and by considering =0.05,

and power of 1- = 80%, at least 20 teeth. Trend of run-

ning in this study was in this way that in each group

10 samples were prepared with dimensions of 10 × 10 ×

10 mm. in IPS-emax heat press group in order to build

cylinders of a block with cross-section dimensions 10 ×

10 × 10 is molded with incremental silicone impression

material and then wax blocks were prepared by melt-

ing the inlay10 wax. Then these wax blocks, were done

sprue, cylindering and were cast by vita ceramic Inge.

Speci c cylinder device: Chewing simulator (CS-4.2 S /

N: A100220128SM01) was used to cylindering (Figure 1).

Cylinder was heated to 800 ° C under to evaporate

and remove the wax pattern. Vita ceramic ingot was

placed within the cylinder by tongs and cylinder was

placed in speci c furnaces. After warming oven to tem-

perature of 920 ° C, ceramic melted slowly and in vac-

uum was injected into the cylinder.Sprue cut off and

the samples were sandblasted by 2-1 times of aluminum

oxide after cooling cylinder. Then the blocks were drool

with powder and liquid of VitaAkzent Plus .wax blocks

was used to make Feldspathic porcelain with dimensions

10 × 10 × 8 mm has been molded with an incremental

silicone impression material and then wax blocks were

prepared by melting the inlay10 wax. Then these blocks

were done sprue and cylindered and were cast by Vero

bond (vita mark) alloy.

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS COMPARISON OF THE EFFECTS OF IPS E.MAX HEAT PRESS LAYERED AND FELDSPATHIC PORCELAIN 477

Hedaiat Moradpoor et al.

Table 1. Mean and standard deviation the amount of wear before and after treatment in two different materials

The vertical height of the buccal

cusp tip of the tooth surface

before the intervention of the

central Tafusay

The vertical height of the buccal

cusp tip of the tooth surface after

the intervention of the central

Tafusay

p-value

Wear rate

Average

Standard

deviation

AverageStandard deviationAverage

Standard

deviation

layered IPS

e.max heat

press

2/59900/34821/91410/3506<0/0010/68490/0673

Feldspathic

Porcelain

2/25150/47691/66560/4596<0/0010/58590/1731

p-value

0/0790/1910/118

comparison before and after the intervention (paired t test)

comparison between the two materials (independent samples t-test)

Porcelaining was done with VMK master (vita mark)

porcelain by thickness of 2mm and external dimensions

were measured by a gauge after cutting the sprue and

sandblasting and grinding alloy with pink and white

stone. Premolar healthy natural teeth of 4 human max-

illary as well as were selected to the total number of

samples and were stored in distilled water until erosion

time. all samples were mounted by Survivor in a plas-

tic mold in the shape of a half-cylinder in-hardening

resin (Ivoclarvivadent) before testing. Then the photos

were taken of dental teeth in Razi Metallurgical Research

Center (Razi Metallurgical Research Center) by stereomi-

croscope (VEGA II TESCAN) in  xed position and a  xed

place was determined for each sample. Distance from

the cusps tip to the desired location was measured by

the Motic Image Plus software. Then natural teeth were

placed in the front samples of feldspathic porcelain and

layered ips-emax heat press in chewing simulator device.

The samples were immersed in distilled water at all times

of erosion. After the erosion test, the photos were taken

of samples by stereomicroscope again in the same previ-

ous position and due to mentioned method the meas-

urement was done for each cusp again; the difference

between the two amounts was recorded and the highest

was recorded per micrometer. Data with SPSS software

version 18 and by using statistical analysis Independent

samples T test were used for statistical analysis. The sig-

ni cant level of 0.05 was considered in this study.

RESULTS AND DISCUSSION

In this study, with the help of Shapiro-Wilk test it was

determined that the data are followed from a normal

distribution (0.05 <p-value). Means of erosion rate

between the two materials of layered IPS e.max heat

press and Feldspathic Porcelain was evaluated by inde-

pendent samples t-test and erosion difference between

the two restoration was not statistically signi cant

(p-value=0.118) although the mean of erosion rate in

Feldspathic Porcelain was less than layered IPS e.max

heat press (table 1).

As it is shown in Table 1; paired t-test showed that

the difference between the mean difference of the verti-

cal height of the tip of the buccal cusps to central fossa

in tooth surface in IPS e.max heat press between before

and after the intervention (0.001> p-value) and in Feld-

spathic Porcelain between before and after the interven-

tion (0.001> p-value) was signi cant.

DISCUSSION

Ceramic materials made with respect to stiffness and

strength of them are usually resistant to erosion, but

erosion tighter than usual their front teeth is what is

made problem in this type of restorations (Heintze,

2008). In the present study, there was no statistically

signi cant difference between the mean of erosion rate

in two restorations of layered IPS e.max heat press and

Feldspathic Porcelain (0.118 = p-value), although mean

of erosion rate in Feldspathic Porcelain somewhat was

lower than layered IPS e.max the heat press.

In a study by Tian et al. (2013) that the erosion rate

of two groups of Porcelain Ceramics, and layered IPS

e.max heat press were studied, the results showed that

the erosion rate on in the layered IPS e.max heat press

ceramic has been much more than Porcelain (Tian, B.M

2013) which is inconsistent with results of this study.

In a study of Esquivel-Upshaw the rate of Front tooth

478 COMPARISON OF THE EFFECTS OF IPS E.MAX HEAT PRESS LAYERED AND FELDSPATHIC PORCELAIN BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS

Hedaiat Moradpoor et al.

enamel erosion has been reported by restoration of IPS

e.max heat press μm 88/3 (Esquivel-Upshaw 2012). in

study of Etman, et al that also studied the erosion of

Front tooth enamel in three types of ceramic restora-

tions, the results showed that after two years of follow-

ing the erosion mean created by Allceram Procera, μm

261, has been for IPS e.max heat press μm 215 and metal

ceramics μm156 that this difference was statistically sig-

ni cant (Etman, 2008).

In this study, Means of vertical height of the tip of

the buccal cusps to central fossa in tooth surface after

the intervention there was no signi cant difference

between the two materials (p-value=0.191); But verti-

cal height means of the tip of the buccal cusps to cen-

tral fossa tooth surface on the material of layered IPS

e.max heat press there was a statistically signi cant

difference between before and after the intervention

(0.001> p-value) and in Feldspathic Porcelain between

before and after the intervention (0.001> p -value). It

is clear that the signi cant erosion has occurred with

regard to these results. But the erosion differences have

not shown obvious difference between two restora-

tions. Heintze et al. by examining erosion rate of front

ceramic teeth and factors affecting on it, have recog-

nized that factors such as the shape of the samples,

surface treatment, enamel thickness, type of milling

device and its geometry shape, grains size and crystal

size are effective in erosion (Heintze, 2008).

In fact, the erosion is related to the friction created

between the two levels, so it can be concluded that

surface properties and conducted interaction will have

important impact by contact in the two levels. Smooth

surfaces have less resistance and therefore less erosion

compared to uneven surfaces; the erosion rate of them

on front teeth will be also more whatever the surface

roughness of restorative materials to be more. For this

reason, it has always tried to maintain the strength of

the restoration; its surface roughness is reduced as much

as possible. According to studies conducted, the surface

roughness is for feldspathic porcelains of MPa 6560 and

for IPS e.max Press, MPa 5800 that due to the proximity

of value of this variable in two restorations examined,

lake of difference in Front tooth erosion is also justi ed

(Al-Shehri 2002).

Another important factor in front tooth erosion frac-

ture toughness. All ceramic materials that have been used

in dentistry so far, has been with much lower fracture

toughness than metals. According to studies for fracture

toughness of IPS e.max Press MPam 1/22/ 1- 4/3 (14)

and for feldspathic porcelain on range of MPam 1/290/0

up to be 1.56 (23), as well as natural tooth enamel frac-

ture toughness has been reported in the range of MPam

1/237/1-7/0 (Heintze, S.D 2008) and natural teeth dentin

has been reported in MPam 1/208/3 (24), that compared

with metals have less fracture toughness between 20 and

100 times. Lee et al in New Zealand during a study have

shown that gold brigade 3 compared to IPS e.max Press

has less abrasive and friction on the tooth enamel and

can be seen signi cant cracks in front enamel surface

of samples of IPSe.max Press examples in comparison

with gold brigade 3 (Lee 2012). Lee and et al differences

in fracture toughness in different materials know as one

of the Justi er factor; so that during the action and the

inclusion of occlusal forces on the surface of the resto-

ration are with micro fracture and lead to bumps and

abuses such as inclusion Crystalline that are going off

the surface of the material; as result leads to accumula-

tion of a lot of pressure on enamel and troughs Gaug-

ing. In addition dug particles can act like an Abrasive

and to create three-dimensional erosion; So it can be

expected that less erosion is created in front teeth in the

restorations with higher fracture toughness (Anusavice,

2013). Given that in terms of fracture toughness as well

as there was no signi cant differences between two

FIGURE 1. A prepared sample and chewing simulator

BIOSCIENCE BIOTECHNOLOGY RESEARCH COMMUNICATIONS COMPARISON OF THE EFFECTS OF IPS E.MAX HEAT PRESS LAYERED AND FELDSPATHIC PORCELAIN 479

Hedaiat Moradpoor et al.

restorations evaluated in this study, so the same Front

tooth erosion is justi able.

CONCLUSION

According to the results obtained in present experimen-

tal study, the means of erosion rate in two restorations

of layered IPS e.max heat press and Feldspathic Porce-

lain has no statistically signi cant difference with each

other, although mean of erosion rate in the Feldspathic

Porcelain has been somewhat lower than layered IPS

e.max heat the press; The results showed that the ero-

sion on both the restorations after intervention has been

signi cant compared to before intervention; As a result,

it can be concluded that these two restorations causes to

signi cant erosion of front tooth enamel, but have no

signi cant difference with each other.

SUGGESTIONS

It is suggested that in future research erosion caused be

evaluated by natural tooth enamel and other high appli-

cable restorations and also be compared by two restora-

tions of layered IPS e.max heat press and Feldspathic

Porcelain. It is also possible to design and carry out

long-term laboratory studies of this kind, to provide the

information necessary to assess the relationship between

laboratory and clinical erosion data.

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