inlayuri estetice posterioare Rondoni.pdf

8/10/2019 inlayuri estetice posterioare Rondoni.pdf

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I industry report _ indirect technique

cosmeticdentistry 1_2008

_The demand for aesthetic results in prostheticrestoration is constantly increasing in our laboratories.More and more patients are coming to the dental office,

desiring and expecting their restorations and even theirfillings to look natural. The aspect of laboratory costs ofaesthetic restorations also plays an increasingly impor-tant role.

In recent years, dental companies have producedmaterials that allow the dentists to better satisfy theseneeds. These materials, called composites, consist of in-organic fillers and are surrounded by an organic matrix.

Research has made progress in the following areas:more resistant substances are being used in the mixture,improving the texture, ie, smoothness and density.

Compared to traditional composites, the new micro-hybrid composite materials used in preservative den-tistry enable direct restorations with improved abrasionresistance and accuracy.

These light-curing composite materials contain75% inorganic fillers with different particle sizes, en-abling great aesthetic results in combination with verystrong mechanical abrasion resistance (Enamel plusHFO, mechanical characteristics; see Tables 1 and 2).

For these reasons our labs use micro-hybrid com-

posite materials for inlays and onlays. Composites areincreasingly replacing ceramics in aesthetic quadrantrestorations because inlays can be done much faster,

therefore saving time and costs for both the laboratoryand the practice.

Dentists quickly realize the excellent accuracy anddurability of these indirect restorations, as well as theapplications in extended occlusal surfaces, particularlywhen they and their laboratories have developed andestablished a standardized method for their technicalimplementation. This applies even more so since dentaloffices use light-curing materials for direct fillings be-cause they permit easy regulation even during cemen-tation of indirect restorations.

_Technique

Even though we are aware of the functional quali-

ties and, above all, the accuracy of gold, we now preferto use a micro-hybrid composite material (Enamel PlusHFO, by Micerium S.p.a., Italy). This especially applies incases where old amalgam fillings or infiltrated ceramicinlays have to be replaced (Figs. 13).

A broad utilization has shown that the material isvery accurate. Additionally, it is easily processed in anylaboratory, a simple cast is sufficient (Fig. 4).

After the model has been mounted in the traditionalmethod with a class IV cast, it has to be verified that all

details and edges are perfectly visible. It is important topay attention to the correct preparation method withlow friction. Additionally, the thinnest pointeg, in the

Posterior aesthetic inlays:

indirect techniqueAuthor_Daniele Rondoni, Italy

accumulatedabrasion[m]

TetricCeram

ColteneMiris

DentsplyEsthet X

Kerr Point4

HFO Sinfony

140

120

100

80

60

40

20

0

200

150

100

50

Table 2

flexibility > 140 MPa

pressure resistance 450 490 MPa

elasticity module > 10.000 MPa

Vickers hardness 75 kg2/mm2

transparency < 35%

Enamel plus HFO

* measured at 63 C, for 13 min. (at 75 C hardness + 20 %)

Table 1

By kind permission of Cosmetic DentistryInternational Edition n.1, 2008


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industry report _ indirect technique I


occlusal central partwith a minimum of 1.5 mm, is re-quired to avoid risk of fracture during cementation.Once closing preparation borders have been deter-mined, they are marked with a wax marker. Thereafterthe preparation area is sealed with a cyano-acrylatebased varnish (Margidur Benzer, Switzerland).

Before proceeding with the composite coating, it isnecessary to block out an area on the bottom of the cav-ity with a neutral wax to facilitate the drainage of thebonding composite during cementation and to allow

correct placement of the inlay (Fig. 5). After isolating theaffected surfaces with a ceramic separator (Temp Sep,Micerium S.p.a., Italy), it should then be prepared for thesubsequent anatomical coating (Fig. 6).

The Enamel Plus HFO composite is a highly fluores-cent dentine with various color saturation for the

restoration of the inner (dentin) zones. Additionally,there are age-based enamels (generic enamel) with dif-ferent luminosity degrees depending on the age of thepatient and the type of restoration (Fig. 7).

To start, small composite portions that correspondto the occlusal plane are fixed with pre-curings using alight-curing unit (Laborlux Micerium S.p.a., Italy) for 20seconds. In cervical areas a UD2 dentine is used, while inthe incisal areas thinner layers (about 0.5 mm) of GE3(generic enamel) with a high luminous value (Figs. 810)

are applied until both the vestibular and the proximalwalls have been rebuilt, while the contact point is care-fully molded (Fig. 11).

Composite coatings along an edge are especially im-portant to assure absolute precision of the restoration.Therefore, it is advisable to use optical magnification de-

Fig. 1 Fig. 2 Fig. 3



Fig. 10 Fig. 11 Fig. 12


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I industry report _ indirect technique

vices. Now, the internal parts of the restoration can becoated.

The dentine coating should allow a natural desatu-ration of the chromaticity through a horizontal appli-cation without losing the translucent and luminous as-pects. Thanks to the HFO Universal-Dentines, that allowa gradually controlled internal chromaticity towardsocclusal areas, this can easily be accomplished. In thedeepest composite coat a high saturated dentin, in thiscase UD3, is applied and pre-cured for 20 seconds. At-

tention needs to be paid to the correct composite solid-ification in order to avoid creating cavities within therestoration and cavities respectively.

For cusp inclinations, or triangular occlusal ridges re-spectively, an UD2 dentine is used, while it needs to becontrolled that the alignment of these elements is in

harmony with correct functional dynamic occlusion(Fig. 12).

After the last dentine layer has been pre-cured, ad-ditional cusps are modeled with white OpalescentWhite (OW), using a silicone brush (T-Pen No. 2,Micerium S.p.a., Italy) (Figs. 13, 14).

When anatomical coating is finished, final polymer-ization is done using light-curing for four minutes.When light polymerization is completed, prior the re-

moval of the restoration from the work model, possiblefunctional inaccuracies can be corrected in the articu-lator using diamond burs (Figs. 15, 16).

Due to the final density and consistency of the ma-terial the finishing can be done as it would be with ce-ramics (Table 2): using a small tungsten bur the occlusal


Fig. 13 Fig. 14 Fig. 15

Fig. 16 Fig. 17 Fig. 18

Fig. 19 Fig. 20 Fig. 21

Fig. 22 Fig. 23 Fig. 24


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industry report _ indirect technique I

fissures are then finalized (Fig. 17). The more regularsurfaces (both proximal and vestibular) are homoge-neously smoothed with abrasive paper cones (Fig. 18).Final polishing is performed in a simple manner withoutlight-curing varnishes, using three polishing pastes

(Shiny System, Micerium S.p.a., Italy) (Figs. 19, 20).

When polishing is finished (Figs. 21, 22) the inlays areremoved from the work model and thoroughly checkedand cleaned.

Prior to delivery to the dental practice in adequatepackaging, all cemented areas have to be sandblastedwith low pressure to facilitate easy fitting of the com-posite inlays (Figs. 23, 24). It is important to rememberthat during cementation, the dentist will be able to usethe same composite that he normally uses for direct fill-

ings.

_Conclusion

Looking back at many years of experience, we can as-sess that todays adhesive systems, in combination withmodern micro-hybrid composites, allow us to makerestorations that go beyond posterior aesthetic inlays.We are now also able to achieve outstanding aesthetic

and durable results with veneers and extended restora-tions in the anterior regions.

The anatomical coating technique in combinationwith Enamel Plus HFO allows us to manufacture

restorations in our laboratory that are routinely beingmanufactured in the dental practice using the sametechnique. These indirect restorations are cheaper,faster and achieve better aesthetic results._

Dr Daniele Rondoni hasworked since 1981 in thedental laboratory Savona,Italy. There, he became ac-

quainted with aestheticrestoration with a specialtyin blending technique withcomposites. He aided in thedevelopment of Enamel

plus HFO Tender blending systems, gives interna-tional lectures, and regularly teaches continuingeducation courses for technicians and dentists athome and abroad.

cosmeticdentistry

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