Ivoclar Vivadent SR Nexco Paste User Manual

Instructions for Use

Table of Contents

4 Product information

Material Usage Composition

PRODUCT

Working times/curing depths Definitions and description

INFORMATION

10 Shade determination – tooth shade, stump shade

Preparation guidelines and minimum thickness

13 Framework-free restorations (inlay/onlay)

Model isolation Liner application Inlay/onlay layering Final polymerization Finishing/polishing Preparing for cementation

20 Framework-free restorations (anterior crown)

Model isolation Liner application Anterior crown layering Final polymerization Finishing/polishing Preparing for cementation

26 Fixed, metal-supported restorations

Framework design Framework fabrication Casting and finishing Conditioning of the framework

PRACTICAL PROCEDURE

Layering diagram Optional: Application of SR Nexco Retention Flow Opaquer application Cervical, Dentin and Incisal layering Final polymerization Finishing/polishing

42 Framework-supported combination dentures

Procedure for combination dentures Matching the shade of SR Nexco to the shade of SR Phonares

47 Modification and characterization of denture teeth

Conditioning of the surface Characterization and customization with Effect and Incisal materials Final polymerization Finishing/polishing/outcome

50 Restorations with gingiva portions

Framework design Starting situation Framework design criteria Contouring Finishing Conditioning of the framework Opaquer application Cervical, Dentin and Incisal layering Gingiva layering Final polymerization

PRACTICAL PROCEDURE

Finishing/polishing

56 General information

Cementation Polymerization parameters Subsequent adjustments

GENERAL

Materials combination table A–D shades Frequently Asked Questions

INFORMATION

Product Information

MATERIAL

SR Nexco Paste is a purely light-curing lab composite with microopal fillers for framework-based and framework-free dental restorations. As the desired shades can be reproduced even with varying layer thicknesses, a true-to-nature appearance can be achieved for fixed and removable dental restorations, even with artificial gingiva. The high content of inorganic opal fillers affords optimum benefits in terms of abrasion, discolouration, processing and surface gloss.

Physical properties of SR Nexco Paste

Together with the respective matrix the inorganic micro-opal fillers impart a homogeneous structure to the material. The balanced ratio between these two components results in outstanding physical properties achieved with the most popular polymerization units available on the market.

SR Nexco Paste

Modulus of elasticity [MPa] 6500 ± 500

Flexural strength [MPa] 90 ± 10

Hardness (Vickers) [MPa] 440 ± 10

Water absorption [µg/mm³] 15 ± 1

Water solubility [µg/mm³] 1 ± 0.5

Esthetic properties of SR Nexco Paste

In transmitted light, the full range of light-optical properties of SR Nexco Paste becomes evident: The opalescence and translucency of SR Nexco restorations correspond to the dynamic light effects of natural teeth. The light behaviour is very similar to that of natural teeth in all areas: the tooth neck, the dentin areas and the incisal area.

This image taken with incident light shows the fluorescence and luminosity of SR Nexco restorations. Natural teeth derive a major part of their brightness effect from their fluorescence. This fluorescence plays an important role in the true-to-nature light behaviour of SR Nexco restorations.

Incisal

Dentin

Margin

Incisal

Dentin

Margin

USES

Indications

Fixed denture prosthetics

Framework-based

– Veneering of metal-supported restorations – Veneering of combination dentures (e.g. telescope crown

veneers) – Veneering of fixed-removable implant superstructures – Veneering of gingiva portions in fixed-removable implant

superstructures – Veneering of CAD/ CAM-fabricated metal frameworks – Masking of model cast frameworks with SR Nexco Opaquer pink

Framework-free

– Inlays/onlays/veneers – Anterior crowns

Modification/characterization

– Superficial characterization of Ivoclar Vivadent resin teeth with

SR Nexco Stains in conjunction with SR Connect and subsequent

layering with SR Nexco Paste layering materials – Shape and shade modifications of Ivoclar Vivadent resin teeth

with SR Nexco Paste layering materials in conjunction with

SR Connect – Modification and characterization of Telio

with SR Nexco Stains, Dentin, Incisal and Effect Shades in con-

junction with SR Connect

CAD and Telio Lab

General note

As is generally known, composites have to meet different demands due to country-specific uses. Composite veneering materials show specific characteristics and properties and their performance and durability can therefore not be compared with that of other C&B materials. The composite restorations may require clinical repair over time, depending on the situation and the individual case. The restorations can be repaired by means of microfilled composites, as described in the section on "Subsequent Adjustments" on page 58.

Contraindications

– Posterior crowns without framework support – Conventional cementation of fixed, metal-free restorations – Framework-free long-term temporaries worn for longer than

12 m onths – Patients with occlusal dysfunctions or parafunctions, such as

bruxism, etc. – Patients with inadequate oral hygiene and substantial drug intake

(e.g. drugs that reduce salivary flow) – All the clinical applications that are not described as an indication

by the manufacturer – Veneering of metal frameworks without the use of SR Link and

SR Nexco Opaquer – The use of non-recommended polymerization devices or bonding

agents – Repairing of chipped denture teeth

COMPOSITION

– SR Nexco Paste layering materials

(Margin, Dentin, Incisal, Effect, Gingiva and Intensive Gingiva

materials) Dimethacrylates (17–19 wt.%); copolymer and silicon dioxide (82–83 wt.%). Additional contents are stabilizers, catalysts and pigments (<1 wt.%). The total content of inorganic fillers is 64–65 wt.% /

46–47 vol.%. Particle size: 10–100 nm.

– SR Nexco Liner

Dimethacrylates (48 w t.%); barium glass filler, silicon dioxide

(51 wt%). Additional contents are catalysts, stabilizers and

pigments (<1 wt.%).

– SR Nexco Opaquer

Dimethacrylates 65–70 wt.%), inorganic filler (<43 wt.%).

Additional contents are catalysts, stabilizers and pigments

(<2 w t.%) .

– SR Nexco Stains

Dimethacrylates (47–48 wt.%); copolymer and silicon dioxide

(49 –50 wt.%). Additional contents are catalysts, stabilizers and pigments

(2–3 wt .%) .

– SR Modelling Liquid

Dimethacrylate (approx. 99%). Additionally, initiators and

catalysts are contained.

– SR Nexco Retention Flow

Dimethacrylates (65–70 wt.%), inorganic filler (30–35 wt.%).

Additional contents are catalysts, stabilizers (<2 wt.%).

– SR Link

Dimethacrylate, phosphate ester, solvents and benzol peroxide

– SR Gel

Glycerine, silicon dioxide and aluminium oxide

– SR Retention Adhesive

Copolymer, resin and softening agent (30 wt.%) solved in

acetone (70 wt.%).

Warning

SR Nexco is intended for use in dentistry and dental technology. Contact of unpolymerized material (pastes) with the skin or eyes must be prevented. Contact with unpolymerized material may have a slight irritating effect and may lead to a sensitization against methacrylates. Customary medical gloves do not provide protection against the sensitizing effect of methacrylates. SR Connect contains methyl methacrylate (MMA). MMA is highly flammable. Therefore, keep away from sources of ignition and do not smoke. MMA is an irritant and is irritating to eyes, respiratory organs and skin. Do not inhale vapours. Do not inhale grinding dust. The safety notes on the individual primary packages and labels have to be observed.

General note

Failure to observe the stipulated contraindications and processing restrictions might lead to clinical failure in certain cases.

Side effects

Systemic side effects are not known to date. In individual cases allergic reactions may occur. In case of a suspected or confirmed allergy to one of the components, SR Nexco Paste or respective other system components must not be used.

Storage instructions

– Store SR Link in the refrigerator (2–8 °C / 36–46 °F). – Store SR Nexco Paste layering materials, SR Model Isolation,

SR Connect at 2–28 °C (36 –82 °F).

– Syringes should be closed immediately after use (exposure to

light causes premature polymerization). – Protect the materials from direct sunlight. – Do not use the products after the indicated expiration date. – Keep material out of children’s reach.

Note on the cleaning of SR Nexco Paste restorations

As the ultrasonic cleaning liquids are highly aggressive, the composite surface may begin dissolve if the liquid is used inappropriately. Therefore, alkaline cleaning agents with a pH higher than 8 must not be used.

– SR Microretentions: 200 –300 µm – SR Macroretentions: 400–600 µm

Copolymer (99.5 wt.%) and titanium dioxide (0.5 wt.%).

– SR Connect

Methyl methacrylate (60–70%), polymethyl methacrylate (<10%),

dimethacrylate (20–30%) and catalysts (3–5%).

– Universal Polishing Paste

Emulsion of aluminium oxide, ammonium oleate, petroleum

distillate and water.

WORKING TIMES/CURING DEPTHS

Working times

SR Nexco materials are sensitive to light. The working time depends on the layer thickness, the shade and the environmental light conditions. Brighter shades react more quickly than darker ones. The values indicated below are average values at a light intensity of 3000 Lux, which corresponds to a bright work space lighting. These maximum values must be taken into consideration when extruding the respective amount of veneering material.

SR Nexco

SR Nexco Liner

SR Nexco Opaquer

SR Nexco Stains

low viscosity

SR Nexco Margin

SR Nexco Dentin

SR Nexco Incisal

SR Nexco Effect

high viscosity

SR Nexco Gingiva

Curing depths

Due to the light sensitivity, the curing depth (intermediate curing with the Quick initial curing light) of SR Nexco materials depends on the shade and above all the layer thickness. Bright and translucent shades cure better, as light can penetrate through these shades more easily than through darker and more opaque shades. These values must be taken into consideration during the layering of the different materials.

SR Nexco

SR Nexco Opaquer max. 0.05 mm

SR Nexco Stains 0.2 – 0. 8 mm

SR Nexco Paste

Incisal, Dentin, Effect

SR Nexco Paste Margin, Gingiva, Intensive Gingiva

Curing depths

(20 seco nds with t he Quick)

Time

2–25 min

4–25 min

min. 2.0 mm

min. 1.0 mm

DEFINITIONS AND DESCRIPTION

Compatibility with polymerization units

High-performance polymerization is requisite in the fabrication of high-quality lab composite restorations. With the excellent lightcuring appliance Lumamat Vivadent, you can achieve an optimum polymerization of SR Nexco restorations and thus benefit from the full potential of this material's physical properties. In addition, the sensor-controlled Quick appliance is available to quickly precure the material. The Quick can also be used for the intermediate polymerization of other light-curing veneering materials. Apart from Lumamat 100, other polymerization appliances may also be used for complete or intermediate polymerization. An overview of the tested appliances and the respective polymerization parameters can be found on page 57.

Compatibility with Ivoclar Vivadent alloys

A metal framework is the basis for any veneered metal-based restoration. To this end, Ivoclar Vivadent offers a wide range of different high-quality alloys which are specifically designed to match their area of indication. This range includes high-gold, reduced gold and base metal alloys. In conjunction with the SR Link bonding system, the alloys establish an ideal metal/composite bond.

When using other alloys, please ask your alloy manufacturer about the compatibility with SR Link and its system components.

100 from Ivoclar

Alloys Au Pt Pd Ag

High-gold

Academy Gold 77.2 <1.0 – 12.7

Harmony

PF 72.0 3.6 – 13.7

Academy Gold XH 70.7 3.6 – 13.7

Reduced gold

Harmony® X-Hard 68.3 2.9 3.6 10.0

XL-X Maxigold Midigold

50 50.0 – 3.5 35.0

62.8 – 3.9 16.1

59.5 – 2.7 26.3

Magenta 50.0 – 6.5 21.0 Minigold Harmony

Universal alloys

3 3.5 – 25.9 50.8

40.0 – 4.0 47.0

BioUniversal PdF 71.1 9.2 – 11.7

Co Ni Cr Mon

Base metal

d.SIGN® 30 60.2 – 30.1 <1.0

Colado Colado

CC 59.0 – 25.5 5.5

NC – 65.6 20.1 1.3

4all – 61.4 25.7 11.0

The range of available alloys may vary from country to country.

Compatibility of SR Phonares® II

Compatibility between denture teeth and lab composite is an important criterion particularly in the fields of partial and removable denture prosthetics. Therefore, the shade of SR Nexco has been specifically coordinated with the shades of SR Phonares II.

Compatibility with IPS d.SIGN

and IPS InLine

The shade concept of SR Nexco and the IPS InLine system has been modelled after the shade system used for IPS d.SIGN. Thus, an Opaquer, a Dentin and a suitable Incisal material are allocated to each tooth shade. The shades of the Effect, Gingiva and Stains materials are coordinated with the shade systems of Ivoclar Vivadent ceramic products, so that a similar esthetic outcome can be achieved with the shadeindependent additional materials. Users are thus offered an efficient work procedure. The benefits include an easy and quick processing in the fabrication of combination dentures and a simplified shade match with existing ceramic restorations.

SR® Accessories

SR Link, 5 ml

SR Link is a metal /composite bonding agent that provides a covalent bond between metal frameworks and SR Nexco. SR Link is an easy-to-use and, above all, tried-and-tested bonding system that can be used in conjunction with a wide selection of alloys. The bonding system is suitable for use on frameworks made of – alloys that contain less than 90% gold, palladium and platinum – alloys that contain less than 50% copper and /or silver – base metal alloys – titanium and titanium alloys

SR Connect, 5 ml

SR Connect is a light-curing conditioner to bond light-curing veneering materials to PMMA, heat- or cold-curing polymers and resin denture teeth. These are the areas of application: Establishing a bonding layer in the case of – individual shade and shape modifications of pre-

fabricated teeth and different veneering materials, such as Telio

– individual shade adjustments of denture base resins.

CAD and Telio Lab.

SR Nexco Gingiva concept

The SR Nexco Paste Gingiva shades are coordinated with the Ivoclar Vivadent Gingiva concept of the IPS InLine system, IPS d.SIGN and IPS e.max. Thus, gingiva with a lifelike shade effect can be created according to the same diagram with all veneering systems particularly in implant superstructures. In addition to the conventional Ivoclar Vivadent Gingiva concept, SR Nexco Paste offers a new Intensive Gingiva shade (IG5) and a Basic Gingiva shade (BG34). These materials can be used for modifications and characterizations of e.g. IvoBase

dentures even

more quickly and easily.

SR Nexco Retention Flow

SR Nexco Retention Flow is a low-

viscosity opaquer component, which can be applied into the undercuts of the retention beads. SR Nexco Retention Flow demonstrates a higher curing depth than the shaded SR Nexco Opaquers and can be quickly and easily applied due to its flowable consistency. The application of SR Nexco provides for a reliable bond between the metal framework and the first opaquer layer.

SR Modelling Liquid, 5 ml

SR Modelling Liquid is used to wet the dental technician's instruments during modelling and as a modelling aid (wetting of the brush to disperse the material, etc.). SR Modelling Liquid must not be used as a bonding agent for the purpose of modifying the consistency or in the case of subsequent adjustments. Use SR Modelling Liquid only in very low quantities.

SR Gel, 30 ml

SR Gel is a glycerine-based masking gel that is impervious to oxygen. The gel is applied to the restoration before polymerization to minimize the formation of an inhibition layer on the surface of the veneering composite. Consequently, the gel ensures complete curing of the restoration surface. Do not apply too thick a layer of SR Gel.

SR Model Seperator, 10 ml

The SR Model Separator is suitable for separating working dies during the fabrication of metal-free restorations and adjoining stone surfaces during lab composite veneering.

SR Retention Adhesive, 20 ml

This adhesive varnish is utilized to affix micro- and macroretention beads to the restoration surfaces after contouring.

Universal Holder

Used to handle disposable brushes and sponges and thereby help facilitate the working procedures in the dental laboratory.

Disposable Brushes, 50x

The disposable brushes are particularly suitable for the application of liquid materials, such as SR Model Separator, SR Link and SR Nexco Opaquer.

SR Microretention Beads, 15 ml SR Macroretention Beads, 15 ml

Two different sizes of retention beads are available, depending on space conditions. – Microretention: 200–300 microns – Macroretention: 400–600 microns

SR Mixing Pad, small

SR Mixing Plate, small

Depending on the material to be processed, the SR Mixing Pad and SR Mixing Plate may be used. The pad is mainly used to process liquid SR Nexco materials so that time-consuming cleaning of the plate can be avoided. In contrast, the plate is used to mix the more viscous composite components. The light protective cover of the plate extends the working time of the materials.

Universal Polishing Paste, 100 ml

The SR Universal Polishing Paste enables quick and efficient polishing of composite and metal restorations. The paste is particularly suitable for prepolishing and principal polishing of SR Nexco veneers.

Disposable Sponges, 50x

The disposable sponges have been modified to fit into the universal holder. They are used to remove the inhibition layer after polymerization of the Opaquer and Liner.

Cannulas, 10x

These application aids can be attached to Liner, Opaquer and Stains syringes. They help achieve more accurate dosing and cleaner application procedures as the extrusion pressure can be controlled.

Cannula Caps, 20x

The cannula caps prevent the material from drying out or polymerizing prematurely while it is in the cannula and provide protection against contamination.

Practical procedure

SHADE DETERMINATION – TOOTH SHADE, STUMP SHADE

Shade determination of the natural tooth

After tooth cleaning, the tooth shade of the non-prepared tooth and/or the adjacent teeth is determined with the help of a shade guide. Individual characteristics have to be considered when determining the tooth shade. If a crown preparation is planned, for example, the cervical shade should also be determined. In order to achieve the best possible true-to-nature results, shade determination should be carried out at daylight. Furthermore, the patient should not wear clothes of intensive colours and /or lipstick.

Die shade selection

Based on the IPS Natural Die shade guide, a die for a frameworkfree restoration is fabriacated. This die is used as control die in conjunction with the restoration to check the shade.

PREPARATION GUIDELINES AND MINIMUM LAYER THICKNESSES

Successful results can only be achieved with SR Nexco veneering material if the guidelines and minimum layer thicknesses are strictly observed. As framework-free SR Nexco restorations are placed using an adhesive cementation method, a toothconserving and defect-oriented preparation technique can be used.

Inlays and onlays

Static and dynamic antagonist contacts must be taken into consideration. The preparation margins must not be located on centric antagonist contacts. A preparation depth of at least 1.5 mm and an isthmus width of at least 1.5 mm must be observed in the fissure area. Prepare the proximal box with slightly diverging walls and observe an angle of >90° between the proximal cavity walls and the prospective proximal inlay surfaces. For inlays with pronounced convex cavity walls without adequate support by the proximal shoulder, marginal ridge contacts should be avoided. Round out internal edges and transitions in order to prevent stress concentration within the composite material. Eliminate the proximal contacts on all sides. Do not prepare slice-cuts or feather edges.

6°

≥1.5

>90°

≥1.5

60°–80°

For onlays, provide at least 2 mm of space in the cusp areas. On the vestibular side, prepare a bevel (10°–30°) to improve the esthetic appearance of the transition between the composite and the tooth. Onlays are indicated if the preparation margin is less than approximately 0.5 mm away from the cusp tip, or if the enamel is severely undermined.

≥1.5

6°

10–3 0°

≥1.5

≥2.0

Anterior crowns

Evenly reduce the anatomical shape and observe the stipulated minimum thickness. Prepare a circular shoulder with rounded inner edges or a pronounced chamfer of at least 0.8 mm. In the anterior

0.8

region, reduce the labial and/or palatal /lingual surfaces by at least

1.0 mm. Reduce the incisal crown third by at least 1.5 mm. Design transitions in such a way that no angles or edges are present.

≥1.0

>1.0

Application procedure – Shade Determination | Preparation Guidelines and Minimum Thickness

1.5

Veneers

If possible, the preparation should be entirely located in the enamel, either in the form of a simple incisal reduction without incisal overlap or conventional preparation with incisal, chamfer-type incisal overlap. Make sure that the incisal preparation margin is not located in the area of the abrasion surfaces. The extent of the incisal reduction depends on the desired translucency of the incisal area to be built up. The more transparent the incisal edge of the intended veneer, the more pronounced the incisal reduction should be. The incisal edge should be reduced by at least 1.0 mm. By preparing orientation grooves using a depth marker, controlled enamel reduction can be achieved. The minimum preparation thickness is approx.

0.6–1.0 mm, depending on the preparation technique selected. Elimination of the proximal contacts is not required. Discoloured teeth may require more preparation. In the cervical area, prepare a cham fe r.

≥0.6

≥0.7

1.0

Framework-free restorations (inlay/onlay)

MODEL ISOLATION

Sealer application

Fabricate a master model or a model with detachable segments according to the impression in the usual manner. Expose and mark the preparation margin. Block out undercuts with blocking-out wax or blocking-out resin to ensure that the restoration can be removed after the polymerization process without damaging the die. Basically, the application of a sealer is recommended to harden the surface and to protect the stone die. However, the sealer layer must not result in any changes of the dimensions of the stone die. It is not mandatory to utilize a spacer, as two coats of SR Model Separator will be applied. If you use a spacer, check as to whether it is compatible with SR Model Se parator.

Sealing the dies and adjoining parts of the model

SR Model Separator is applied in two thin coats. Apply the first coat generously and make sure that all areas of the die are well covered. Watch out for sharp edges (incisal edges) in particular. Then allow to react for 3 minutes. After the reaction time, apply a second layer in a thin coat, invert the model and allow to dry for 3 minutes. Additionally, apply SR Model Separator to adjoining model surfaces that may come into contact with SR Nexco including counterbite, allow to react for a short time, and then disperse excess material with oil-free compressed air.

Fabrication of a die coated with sealer as the working basis.

Practical Procedure – Framework-free Restorations (Inlay/Onlay)

Inlay (and onlay)

Apply first coat of SR Model Separator generously, watch out for sharp edges, and allow to react for 3 minutes. Isolate model areas.

APPLYING THE LINER

SR Nexco Liner combination table

BL A B C D

Tooth BL3 BL4 A1 A2 A3 A3.5 A4 B1 B2 B3 B4 C1 C2 C3 C4 D2 D3 D4

Liner BL BL 1 2 2 3 4 1 2 3 3 1 5 5 4 5 5 5

Procedure for non-discoloured cavities

– Apply Liner clear to the cavity

walls and the cavity floor (dentin area) for an optimum chameleon effect.

– Apply Liner incisal in the

marginal areas (course of natural enamel) to achieve a harmonious transition between the shade of the restoration and natural tooth structure without grey lines.

Procedure for slightly discoloured cavities

– Mask dark areas using a Liner in

an appropriate shade (1–5).

– Coat the remaining portions of

the cavity, except the marginal areas, with Liner clear.

– Apply Liner incisal in the marginal

areas (course of natural enamel) to achieve a harmonious transition between the shade of the restoration and natural tooth structure without grey lines.

Procedure for severely discoloured cavities

– Mask the entire cavity, except

the marginal areas, using a Liner in a corresponding shade (1–5).

– Apply Liner incisal in the marginal

areas (course of natural enamel) to achieve a harmonious transition between the shade of the restoration and natural tooth structure without grey lines.

Liner clear

Liner incisal

Liner 1–5

1st Liner application (Clear, 1–5)

Extrude the desired amount of the ready-to-use Liner paste from the syringe and spread it out slightly on the mixing pad using a disposable brush. First, apply the Liner to the cavity walls and cavity floor in a thick coat and precure each segment for 20 seconds using a Quick curing light. Make sure to fully cover all areas, as the Liner provides an essential bonding surface to the luting composite. Do not cover marginal areas at this stage (course of natural enamel).

Generously cover the cavity walls and floor with the 1st liner cover and precure with Quick for 20 seconds for each segment.

2nd Liner incisal application in the marginal area

After the application of the first Liner layer to the cavity walls and floor, apply Liner incisal in the marginal areas so that all cavity surfaces are coated with Liner. Apply Liner incisal up to the preparation margin in order to ensure a reliable bond between the preparation margins and the luting composite. This measure helps to reduce premature discolouration between the restoration margins and tooth structure.

Apply Liner incisal to the marginal areas or the course of the natural enamel and precure each segment for 20 seconds

Polymerizing the Liner Appliance Time Program

Precuring time per segment Quick 20 s –

Practical Procedure – Framework-free Restorations (Inlay/Onlay)

– The entire inner surface of the restoration has to be covered with SR Nexco Liner. The layer

thickness should be at least 150 µm. Thin out the Liner towards the preparation margin.

– Do not separate polymerized SR Nexco Liner from the die.

Removing the inhibition layer after polymerization of the Liner

Thoroughly remove the resulting inhibition layer using a disposable sponge (do not use a solvent); make sure that the Liner surfaces are free of residue. Make sure that the Liner shows a mat surface.

Thoroughly remove the inhibition layer with clean disposable sponges.

INLAY/ONLAY LAYERING

Adapt the first layer firmly (press into place) to ensure an effective bond between the Liner and lab composite and precure each segment for 20 seconds using a Quick curing light. The shade effect in the interdental area and cavity may be increased by means of Occlusal Dentin orange. Slightly emphasize the marginal ridges and cusps with Dentin. Subsequently, begin the process of building up the cavity with Dentin materials. Make sure to provide adequate space for the subsequent application of Incisal and Effect materials. The translucency of the restoration may be increased by means of coloured Transpa materials, such as Transpa orange-grey and Transpa brown-grey. Layer SR Nexco Paste layering materials step by step and precure each individual layer. After building up and precuring the dental plateau, apply characterizations with SR Nexco Stains and precure for 20 seconds. Next, complete the restoration using Incisal and Transpa materials. The cusp tips and triangular ridges may be supplemented with a fine layer of Opal Effect 3 and 4. Adapt firmly and create smooth, rounded transitions between the layers using SR modelling instruments and synthetic brushes.

Increase the shade effect in the interdental and cavity area with Occlusal Dentin. Outline the marginal ridges with Dentin and create a plateau with various Dentin materials.

Apply characterizations with SR Nexco Stains, precure with the Quick and cover with Incisal and Transpa materials.

Precure each intermediate segment for 20 seconds using the Quick curing light.

Design a lifelike occlusal morphology and subsequently precure all areas for 20 seconds using Quick.

– It is essential to observe the stipulated curing depths and maximum layer thickness of the

individual materials during the layering procedure.

– If the maximum layer thickness is exceeded, break up large portions into several increments

and precure each increment for 20 seconds.

– SR Nexco Stains always have to be coated with layering material (e.g. Incisal, Transpa).

CONDUCT FINAL POLYMERIZATION

After the layering procedure has been completed, all layers must be precured. To make sure that this is the case precure each segment for 20 seconds using a Quick curing light. Next, apply SR Gel on the entire veneering surface ensuring that all areas are fully covered and the layer is not too thick.

Apply a covering, but not too thick layer of SR Gel and secure the dies on the object holder in the correct position.

Practical Procedure – Framework-free Restorations (Inlay/Onlay)

Polymerization Inlay/onlay

Appliance Time Program

Precuring time per segment Quick 20 s –

Conduct final polymerization Lumamat 100 11 m i n P2

For the parameters of other polymerization devices, please go to page 57.

FINISHING / POLISHING

After completion of the polymerization procedure, completely remove SR Gel from the restoration using running water and/or a steamer. Carefully remove the restoration from the die. If the restoration is removed at a later stage, it is advisable to warm up the stone die by means of steam/hot water. Finish the restoration with cross-cut tungsten carbide burs and fine diamonds. It is advisable to use low speed and light pressure. Make sure to rework the entire restoration to remove the inhibition layer of approximately 30 µm. Carefully taper the margins of the restoration, lightly grind the margins, and adjust proximal and occlusal contact points. Subsequently, recreate a lifelike tooth shape and surface structure. The inhibition layer must be removed from the entire SR Nexco surface.

Remove SR Gel and carefully remove the restoration from the die. Remove the inhibition layer and finish the surface with cross-cut burs.

Polishing

Finishing

Carefully smooth out the ridges of the occlusal surface and proximal surfaces with rubber polishers and silicone polishing wheels. Pay particular attention to the margins in order to avoid rendering them too short.

Prepolishing and high-gloss polishing

The restorations are prepolished and polished to a high gloss using a goat hair brush, cotton or leather buff as well as Universal Polishing Paste. Use low speed and slight pressure for prepolishing and high-gloss polishing. Adjust the pressure at the handpiece, not with the polishing motor. In order to optimally polish the occlusal surfaces, we recommend modifying the goat hair brushes to become star-shaped so that only the desired areas can be polished due to the smaller size of the brush. Depending on the type of high gloss desired, leather buffing wheels can be used to achieve a high shine, while cotton buffs are used to achieve a lesser degree of lustre.

Results

PREPARING FOR CEMENTATION

Practical Procedure – Framework-free Restorations (Inlay/Onlay)

Adhesive cementation is mandatory for framework-free SR Nexco Paste restorations.

In order to achieve an excellent bond with the luting composite, the cavity side of the restoration has to be carefully blasted with Al subsequent cleaning, the cavity side is again roughened with a 50–100 µm diamond directly prior to the adhesive cementation. Finally, the surfaces are silanized (e.g. with Monobond® Plus) to enable a chemical bond.

(80 –100 µm) at 1 bar / 15 psi pressure in the laboratory. Following the try-in in the dental practice and

2O3

Framework-free restorations (anterior crown)

MODEL ISOLATION

Applying the sealer

Fabricate a master model or a model with detachable segments according to the impression in the usual manner. Expose and mark the preparation margins. Block out undercuts with blocking-out wax or blocking-out resin to ensure that the restoration can be removed after the polymerization process without damaging the die. Basically, the application of a sealer is recommended to harden the surface and to protect the stone die. However, the sealer layer must not result in any changes of the dimensions of the stone die. It is not mandatory to utilize a spacer, as two coats of SR Model Separator will be applied. If you use a spacer, check as to whether it is compatible with SR Model Separator.

Sealing the dies and adjoining parts of the model

SR Model Separator is applied in two thin coats. Apply the first coat generously and make sure that all areas of the die are well covered. Watch out for sharp edges (incisal edges) in particular. Allow the layer to react for 3 minutes. After the reaction time, apply a second layer in a thin coat, invert the model and allow to dry for 3 minutes. Additionally, apply SR Model Separator to adjoining model surfaces that may come into contact with SR Nexco including counterbite, allow to react for a short time, and then disperse excess material with oil-free compressed air.

Fabrication of a die coated with sealer as the working basis

Applying two layers of SR Model Separator

APPLYING THE LINER

Extrude the desired amount of the ready-to-use Liner paste from the syringe and spread it out slightly on the mixing pad using a disposable brush. First, apply the Liner thinly on the die surfaces. Make sure to fully cover all areas, as the Liner provides an essential bonding surface to the luting composite. The Liner layer must be at least 150 µm thick and has to be precured for 20 seconds per segment using the Quick.

Apply the Liner in a minimum layer thickness of 150 µm. Precure each segment for 20 seconds using a Quick curing light.

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