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Product Dossier

ELIPAR TRILIGHT

Elipar TriLight – The Intelligent Light Curing Unit 1

Contents

1. Preface.................................................................................... 1

2. Introduction............................................................................ 2

2.1. History ................................................................................ 22.2. Motivation........................................................................... 32.3. Indications.......................................................................... 4

3. Technical Background........................................................ 5

3.1. Curing Principle .................................................................. 63.2. Calibration Function............................................................ 73.3. Physical Parameters .......................................................... 8

4. Equipment Concept.............................................................. 9

4.1. Assemblies ........................................................................ 94.2. Safety Functions.............................................................. 10

5. Test Results ......................................................................... 11

5.1. Internal Measurements.................................................... 115.2. External Measurements at Universities.......................... 125.2.1. Polymerisation Stresses................................................. 125.2.2. Marginal Behaviour.......................................................... 15

6. Instructions for Use............................................................ 17

6.1. Selection of Mode ........................................................... 176.2. Selection of Curing Time ................................................ 176.3. Basic Settings.................................................................. 18

7. Summary .............................................................................. 19

8. Bibliography ........................................................................ 20

8.1. Literature relating to ELIPAR TRILIGHT ....................... 208.2. General Literature............................................................ 20


1. Preface

ELIPAR TRILIGHT is a technologically leading high-performance light

polymerisation unit for dental materials which are polymerised under visible blue

light in the mouth. It represents a successful progression of the ELIPAR series

and rounds off the ELIPAR HIGHLIGHT line already available.

The number of light-curing restorative materials and luting cements is constantly

increasing for everyday usage within the dental surgery. The development of

light polymerisation units has likewise made significant progress in recent years

and has thus helped contribute towards an improvement in restoration quality.

Dentists are becoming increasingly aware of the importance of soft-start

polymerisation which was first made possible with the ELIPAR HIGHLIGHT.

Soft-start polymerisation reduces the stresses produced in the restorative

material during polymerisation and thus has a positive effect on marginal

behaviour.

Another aspect, also coming under greater discussion in the scientific sector, is

the uniformity of the light intensity, firstly during the service life of a lamp, but also

from one lamp to another following a change in lamps. The practitioner is only

guaranteed optimum restoration quality if he can rely on such uniformity.

These two aspects – development of stress reduced curing and uniformity of

light intensity – have been the focus points for the development of ELIPAR

TRILIGHT.


ELIPAR TRILIGHT is thus the newest high-performance light polymerisation unit

to offer a light intensity increasing at an exponential rate and a calibration option

providing uniform light intensity at all times, even after changing lamps.

2. Introduction

2.1. History

The long-term clinical success of composite restorations (compomers are

treated here and below as a subgroup of composites) depends not only on the

optimum material properties of the restorative material and the use of a suitable

dentine adhesive system, but also on complete and proper polymerisation of

the restorative material and the adhesive system.

The capacity of the light polymerisation unit, defined by the radiation flux density

(mW/cm2), has a major effect on the degree of polymerisation of dental

composite materials, in addition to the ambient temperature. Composite

material which has not undergone full polymerisation may impair the mechanical

and physical material properties, increase the tendency towards discoloration

and the levels of water absorption or cause pulpal irritation due to

unpolymerised monomer residues. Numerous manufacturers have increased

the capacity of their light-polymerisation equipment to a growing extent in line

with the recommendations of leading authors. These include concerns about the

use of light polymerisation equipment at the limits of their maximum capacity,

and the fact that, with light polymerisation equipment offering low capacities of

approx. 200 mW/cm2, complete polymerisation can only be expected to depths

of approx. 1 mm and the equipment offers no reserves whatsoever in terms of

performance.

However, the question of the optimum radiation density which should be used

for polymerisation of a composite material has remained generally unanswered

to date. There has been discussion about a polymerisation model which, with a


lower radiation density, primarily results in longitudinal growth of polymer chains

with reduced stress in the restorative material and less polymerisation

shrinkage although a high level of emitted energy might cause fast, close-

meshed cross-linking at an increased polymerisation rate and greater stresses

in the restorative material. However, in general the measurable polymerisation

shrinkage with increasing polymerisation always comes close to the material-

related linear polymerisation shrinkage of modern fine particle hybrid

composites in the order of 3-4%. Lower values for the measured polymerisation

shrinkage with less effective polymerisation energy are thus more probably due

to an incomplete polymerisation reaction.

2.2. Motivation

Despite improvements in the more recent dentine bonding systems which can

offer bond strengths of 25-30 MPa, marginal gap formations, which become

more serious as the length of placement increases, are still occurring, in

particular at the margins of composite restorations limited by dentine. Important

factors here are the polymerisation shrinkage of the composite and the creation

of internal stresses which impair bonding to the remaining tooth substance. For

this reason various development projects and studies aim to reduce both

polymerisation shrinkage and the internal stresses to a minimum. One

promising approach that is being taken to solve this problem is the attempt to

influence the polymerisation kinetics using modified light curing methods.

ELIPAR HIGHLIGHT was the first commercially available polymerisation unit

which could be used to influence the reaction kinetics during polymerisation in a

specific manner. In this case the light intensity increases step by step. This

stepped polymerisation process reduces the stresses in the restoration

composite without impairing the mechanical properties or the residual

monomer content.


If, in contrast to stepped polymerisation, the light intensity is increased on a

continuous basis, a further beneficial effect on marginal behaviour can be

forecast. With ELIPAR TRILIGHT multistep polymerisation is carried out by

means of an exponential increase in light intensity within the first 15 seconds. In

addition ELIPAR TRILIGHT also offers the option of performing light

polymerisation at a medium (Medium) or constant light intensity (Standard).

Another aspect which was taken into account when developing ELIPAR

TRILIGHT was the variation in light intensity for the unit when changing from one

lamp to another. The light intensity of lamps may vary by up to ±20% due to

production-related factors. This circumstance may ultimately detract from the

optimum material properties of composites subjected to such light-curing

methods. For this reason ESPE has developed a software-aided electronic

feature to deal with this unsatisfactory situation. In addition to the patented

intensity control system, already integrated in the ELIPAR HIGHLIGHT which

ensures a uniform light intensity for the entire service life of one lamp, ELIPAR

TRILIGHT allows the entire system (lamp, filter, light guide) to be "calibrated" to

the defined light intensity value of 800 mW/cm2 after changing lamps.

2.3. Indications

ELIPAR TRILIGHT is a multipurpose light polymerisation unit for composites,

compomers and light-curing glass ionomer cements. The light curing times are

not affected by the modified increase in light intensity. For this reason the curing

times specified in the respective instructions for use are valid for all

polymerisable products available on the market. These times are summarised

for ESPE products in Table 1:


Product Curing time [sec]

Restoration compositesPertac II 40Visio-Molar 40Visio-Fil 40Visio-Dispers 40Visio-Seal 20Cavit LC 20 for layer thickness

< 6mm, 40 for < 9mmLuting compositesCompolute 40 per restoration surfaceSono-Cem 40 + 20 per addit. restoration

surfaceCompomersHytac 40Adhesive systemsEBS-Multi 20Hytac OSB 10Visio-Bond 20Light-curing glass ionomersPhotac-Fil Quick 20 (DBO: 40)Accessories f.glass ionomersKetac-Glaze 10

Tab. 1: Curing times for ESPE products


3. Technical Background

3.1. Curing Principle

Studies carried out with experimental light units have shown that multistep

polymerisation has a positive effect on marginal behaviour, in comparison with

two-step polymerisation. This discovery resulted in the idea of not increasing

the light intensity abruptly after 10 sec, but at an exponential rate (Exponential

mode). Fig. 1 compares the progression of light intensities for ELIPAR

HIGHLIGHT and ELIPAR TRILIGHT.

[ m W / cm2]

10s 20s 30s 40s 10s 20s 30s 40s

ELIPAR HIGHLIGHTHiHIGHLIGHT

ELIPAR TRILIGHTTTRILIGHT

200

400

600

800

200

400

600

800

[mW/ cmmm

2]

Fig. 1: Progression of light intensities for ELIPAR HIGHLIGHT and ELIPAR

TRILIGHT

Another aspect that was taken into consideration when developing ELIPAR

TRILIGHT was the option of selecting a medium light intensity level. Light units

with high outputs are characterised by an increase in temperature during light

curing. Particularly in the case of bonding agents, liners with free-flowing

composites or cervical cavities which preclude the use of a rubber dam, there is

the risk of a marked increase in the temperature of the gingiva or pulp. With


these indications in mind ELIPAR TRILIGHT offers the option of using a lower

light intensity (approx. 450 mW/cm2) for polymerisation (Medium mode).

However the polymerisation period increases to double the curing time in such

cases (not applicable for layer thicknesses of less than 0.5 mm or for

adhesives) to ensure optimum material parameters.

There is also the option of carrying out curing at a constant light intensity during

the entire curing period of the composite to be cured (Standard mode).

3.2. Calibration Function

In addition to the various curing methods described above, ELIPAR TRILIGHT

now offers a brand-new feature for calibration of the unit when using different

lamps. The intensity of radiation of conventional equipment varies by up to

±20% when changing from one lamp to another depending on the

manufacturer. Such variations may make it impossible to reproduce

polymerisation results. With ELIPAR TRILIGHT the intensity of radiation of the

lamp is set to an output of 800 mW/cm2 using the calibration unit.


3.3. Physical Parameters

The light is generated using a tungsten-halogen lamp specially adapted for

dental applications. The light produced is then filtered so that only blue light in

the wavelength range 400 – 515 nm is emitted (see Fig. 2), thus preventing the

material to be polymerised from being heated up unnecessarily through heat

radiation.

The power consumption of the entire unit is approx. 100 W, and 75 W for the

lamp.

When calibrated the lamp radiates 800 mW/cm² in the wavelength range

specified above and 450 mW/cm² in reduced Medium mode.

0

100

200

300

400

500

600

300 400 500 600 700 800

Wavelength [ nm ]

Lig

ht

Inte

nsi

ty [

arb

itra

ry u

nit

s ]

Fig. 2: Emission range of ELIPAR TRILIGHT


4. Equipment Concept

ELIPAR TRILIGHT is a light polymerisation unit in which the light is generated in

the hand unit. This means that there are two housings which are structurally

separate from each other – the hand unit and the basic unit.

4.1. Assemblies

In the basic unit the main assemblies are the voltage transformer and the

processor board. The processor board uses a microprocessor to control and

monitor all adjustable functions, the light intensity, the calibration unit and the

light intensity measuring functions. It performs internal monitoring of the output

and corrects any deviations caused for example by ageing of the lamp or power

supply deviations.

All functions such as time or mode selections are carried out using a membrane

keypad for reasons of hygiene. The results of the light intensity measurements

are displayed digitally, rounded off to 50 mW/cm². An audible warning signal is

emitted if the value of 1000 mW/cm² is exceeded.

The hand unit also includes a control board, in addition to the lamp, filter and

fan. All the major light polymerisation functions can be selected or controlled

using the membrane keypad attached to the hand unit.

All plastic parts included in the basic unit are made of impact-resistant

polycarbonate, while the parts in the hand unit are made of heatproof

polyethylene-terephthalate. The external parts of the hand unit are also insulated

to protect them from the heat radiated by the lamp.


4.2. Safety Functions

Overheating of the hand unit and the transformer is prevented by means of a

thermostat for each item. If the value of 1000 mW/cm² is exceeded during the

light measurements, an audible warning signal is emitted. If the value of 800

mW/cm² is not attained on calibration of a new lamp, the error signal is also

emitted and “EEE” will appear on the display. However, the unit can be

operated in an uncalibrated state.

If the lamp is affected by serious ageing, the microprocessor may be unable to

maintain a uniform light intensity. In this case, a malfunction signal will also be

heard, as in the case of a burnt-out filament or a power voltage falling outside

the permissible range.

For more security, the unit shows through a blinking display “CAL” that you have

to do another calibration check always after 10 hours operating time net.

Although the unit always stays operational.


5. Test Results

5.1. Internal Measurements

The measurements were carried out in the Clinical Research Laboratory in

accordance with ISO 4049 (resin-based restorative materials) and DIN 53456

(hardness test using indentation method). All tests were performed on the curing

methods available - Medium, Standard and Expo. The curing times in Medium

mode were twice as long as specified in the relevant instructions for use. Table

2 summarises the results obtained for the tested products.

Pertac II Photac-Fil Quick

Aplicap

Flexural strength Medium 112±8 42±4

[MPa] Standard 113±7 37±6

Expo 111±11 34±4

Compressive

strength

Medium 424±4 178±7


Expo 414±20 181±7

Surface hardness Medium 240±11 223±11


Expo 287±58 218±12

Water absorption Medium 0.1±0.7 n.b.

[mg/mm3] Standard 0.9±0.7 n.b.

Expo -0.3±0.6 n.b.

Tab. 2: Mechanical properties of PERTAC II, and PHOTAC-FIL QUICKafter light curing with ELIPAR TRILIGHTWithin the limits of standard deviations equally good mechanical properties

were obtained for the products examined with all three curing methods.


5.2. External Measurement at Universities

5.2.1. Polymerisation Stresses

Photoelasticity Dr. C.-P. Ernst (University of Mainz)

Photoelastic investigations are used to portray the stresses to which the

surrounding material and boundary surface are subjected during the

polymerisation of composites. With this method it is possible to make a simple

and easily reproducible comparison between the polymerisation shrinkage

stresses for different products.

During the investigation performed at the University of Mainz a significant

reduction in the polymerisation stresses was observed for all the composites

examined.

The following figure shows an example of a photoelastic picture. A composite

restoration has been placed in an epoxy resin plate with a centre hole, bonded

and allowed to cure. This is represented by the black circle in the middle. The

stresses and forces caused by polymerisation shrinkage can be seen in the

surrounding area. The number, density and position of the black circles is

proportional to the stress acting on the adhesive bond.

As the pictures are rotationally symmetrical, the two halves have been

overlapped to demonstrate the stresses more clearly. Fig. 3 makes a

comparison between a conventionally cured sample, 5 minutes after the end of

polymerisation on the left, and a sample cured in Exponential mode on the right.

Fig. 4 shows the same samples 1 hour after the end of polymerisation.


Fig. 3 Photoelastic picture of PERTAC II, on the left cured using the

conventional (Standard) method, on the right cured in Exponential

mode; picture taken 5 min after the end of polymerisation


Fig. 4: As Fig. 3; picture taken 1 h after the end of polymerisation

In both pictures it can be seen that the restoration cured using the conventional

method subjects the boundary surface and the surrounding material to a much

higher stress. This demonstrates the potential of the exponential polymerisation

process in terms of stress reduction.

The pictures can be used to calculate the load to which the adjacent area is

subjected. Fig. 5 shows the data for a number of selected composites.

0

1

2

3

4

5

6

7

Pol

ymer

isat

ion

stre

ss [M

Pa]

Pertac II Solitaire Definite Visio-Molar

Standard

Expo

Fig. 5: Polymerisation stresses of various restoration composites

Polymerisation stress Dr. M. Bouschlicher (University of Iowa)

A reduction in stresses was also observed in the investigation performed at the

University of Iowa. This study also included a comparison with ELIPAR

HIGHLIGHT. The Exponential mode (multistep polymerisation) resulted in a

further improvement in the results compared with two-step polymerisation (Fig.

6).


0

5

10

15

20

25

30

35

Pol

ymer

isat

ion

Shr

inka

ge

Forc

es [N

]

Elipar Highlight Elipar Trilight(Exponential)

Elipar Trilight(Standard)

Fig. 6: Polymerisation stresses of various restoration composites

5.2.2. Marginal Behaviour

Colour penetration test Dr. J.O. Burgess (Louisiana State University)

In addition to the reduction in stresses a positive effect on marginal behaviour is

another point in favour of the exponential light curing of composites.

0

0,5

1

1,5

2

2,5

Mic

role

akag

e

Elipar Trilight(Exponential)

Elipar Trilight(Standard)

XL 3000

Fig.7: Colour penetration test in Class V restorations with various curing

methods (Z100)


In this study it was not possible to influence the marginal behaviour of Z100 to

any statistically significant extent (Fig. 7). One reason for this is possibly the

high initiator content in Z100 which allows the gelification point (time at which

the free-flowing property of the composite is no longer observed) to be reached

sooner despite the initially lower level of polymerisation energy. However, the

positive effect of ELIPAR TRILIGHT is more apparent in the case of composites

which do not polymerise so quickly.

Colour penetration test Dr. C.-P. Ernst (University of Mainz)

In contrast to the above results, a positive effect on marginal quality was

observed in the study carried out by Dr. Ernst (Fig. 8). The composites used

here are characterised by much better polymerisation kinetics with the onset of

exponential light curing. In the case of PERTAC II the positive effect obtained

was of statistical significance.

0

0,20,4

0,60,8

1

1,21,4

1,61,8

Col

our p

enet

ratio

n at

de

ntin

e m

argi

ns

Pertac II TetricCeram

Definte SureFil

Standard

Expo

Fig. 8: Colour penetration test in Class V restorations


6. Instructions for Use

6.1. Selection of Mode

The "Mode" pushbutton on the basic unit or the hand unit is used to select the

required curing method. If the operator selects curing times which preclude the

new curing method for safety reasons, the system automatically switches to the

next curing time.

When using the "med" setting for polymerisation near the pulp or gingiva it is

advisable to double the curing time due to the reduced light intensity (not

necessary for layer thicknesses of less than 0.5mm).

When "med" mode is used, the light will flicker slightly due to technical reasons.

This is an additional indication of this mode and has no effect on polymerisation

quality.

6.2. Selection of Curing Time

Press the pushbutton with the required curing time (10, 20, 40, 60 or 80).

Alternatively repeatedly press the pushbutton "sec" on the hand unit until the

required time is displayed.

In "med" mode all curing times are possible.

In "exp" mode curing times of "40" and "60" are possible.

In "std" mode curing times of "10", "20", "40" and "60" are possible.


6.3. Basic Settings

There is also the option of setting the curing method, the curing time and

additional audible signals as default values as required. These programmed

values are reset whenever the unit is switched on. The mode and the curing time

can be adjusted irrespective of the default setting when the unit is switched on,

e.g. when using different products.

When delivered the unit has the following settings: curing time 40 sec, "exp"

(Exponential mode), audible signal when light is switched on, after 20 sec and

when it is switched off.

Curing time

Press the required pushbutton ("10", "20", "40", "60" or "80") while the unit is

switched off then switch on the power at the same time. Two short signals will

confirm that the program value has been stored. The time selected is indicated

via the displays on the basic unit and the hand unit.

Curing method

Press the "Mode" pushbutton while the unit is switched off and turn on the power

switch at the same time. The "med" indicator will flash. If the "Mode" pushbutton

is pressed again, the system will jump to the next mode. When the required

mode has been set (appropriate indicator flashing), press the "Mode"

pushbutton and hold down for 3 sec. Two short signals will confirm that the new

program value has been stored.


7. Summary

The studies into the material properties have shown that ELIPAR TRILIGHT is

ideally suited as a light polymerisation unit for dental materials. The use of

ELIPAR TRILIGHT has a positive effect on the reduction of stresses and

marginal behaviour.

ELIPAR TRILIGHT provides for three different polymerisation methods:

Standard, Exponential and Medium. All three options result in identical

mechanical properties, with light curing in “Medium” mode involving an increase

in the curing time.

ELIPAR TRILIGHT can be easily programmed at the main unit using a hygienic

membrane keypad. The curing times and modes can also be selected by

means of a switch on the hand unit.

In addition, thanks to ELIPAR TRILIGHT with its integrated calibration function

the Dentist can be sure of reproducing the restoration quality due to correctly

adjusted light intensity.


8. Bibliography

8.1. Literature relating to ELIPAR TRILIGHT

N. Brand, C.-P. Ernst, B. Willershausen

“Reduction of polymerization forces with soft-start polymerization – a photo-elastic investigation”J. Dent. Res. (IADR Abstract # 2339), 1999.

J. R. Dunn, C. A. Munoz, J. Sy-Munoz, N. Jessop

“Composite Depth of Cure using 3 curing modes, Standard, Medium &Exponential”J. Dent. Res. (IADR Abstract # 2321), 1999.

U. Frommator, C.-P. Ernst, B. Willershausen

“The influence of soft-start polymerization on marginal integrity of class Vfillings.”J. Dent. Res. (IADR Abstract # 3545), 1999.

M. R. Bouschlicher, D. B. Boyer

“Effect of Ramped/Stepped Light Intensity on Polymerization Shrinkage Forces”J. Dent. Res. (IADR Abstract # 2322), 1999.

R. S. Walker, J. O. Burgess

“Microleakage of Class V Composite Restorations with Different Visible-Light-Curing Methods.”J. Dent. Res. (IADR Abstract # 397), 1999.

8.2. General Literature

C. P. Ernst

“ELIPAR HIGHLIGHT der ESPE-Dental-Medizin: In der Lichtpolymerisationmehrstufig von 150 bis 170 Watt arbeiten.”Die Zahnarzt Woche, 37/11, (9/1996).

M. Folwaczny, A. Mehl, C. Benz, R. Hickel

“Physical properties of compomer-materials after softstart-polymerization.”


Arbeitsgemeinschaft für Grundlagenforschung, Mainz, (1/1998).A. Mehl, J. Manhart, L. Kremers, K.-H. Kunzelmann, R. Hickel

“Physical Properties and Marginal Quality of Class II Composite Fillings afterSoftstart-Polymerization.”IADR Orlando, Abstract # 2121, (3/1997)

A. Massimano, G. Mori, G. Goracci

“Effects of Curing Light Intensity on Microleakage of Class V CompositeRestorations.”IADR Madrid, Abstract # 162, (9/1997)

P. Koran, R. Kürschner

“Stress Reduction in Composites due to Two-Step-Polymerization.”IADR Orlando, Abstract # 2393, (3/1997)

C. P. Ernst, R. Kürschner, B. Willershausen

“Stress reduction in composite resin by means of a two-step polymerization unit– a photoelastic investigation.”IADR Madrid, Abstract # 292, (9/1997)

R. Kürschner, P. Koran, E. Winter, A. Bauer

“Photoelastic Determination of Marginal Tensile Forces due to CompositeShrinkage.”IADR Nizza, Abstract # 420, (6/1998)

D. C. Watts, A. Al-Hindi

“‘Soft-Start‘ Photo-Polymerisation Effects in Resin-Composite Restoratives.”IADR Nizza, Abstract # 216, (6/1998)

M. Degoes, J. O. Burgess, X. Xu

“Marginal Adaptation in Class 5 Composite Restorations with Four CuringUnits.”

P. Koran, R. Kürschner

“Effect of sequential versus continuous irradiation of a light-cured resincomposite on shrinkage, viscosity, adhesion, and degree of polymerization.”Reprint – American Journal of Dentistry, Vol. 11, No.1, (1/1998)

C. P. Ernst, R. Kürschner, B. Willershausen

“Polymerisationspannung in Kompositmaterialien bei Verwendung eineszweistufigen Lichtpolymerisationsgerätes.”


Acta Med. Dent. Helv., Vol. 2, (8/1997)

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