Partners in Progress ^7 BEGO

Achieving success with the BEGO System – What does this mean for you? For over 45 years BEGO has offered a coordinated system of materials, alloys and equipment, as well as training courses on the fabric ation of fixed restorations suitable for veneering with ceramics. Although the traditional skill of the dental technician has undergone major changes following the introduction of CAD/CAM technology in recent years, the key steps of the work process have retained their importance. Our top priority here is safe usage and further processing by dental technicians. As an innovative dental company...

Frame production and ceramic veneering Preventive error management 36

Dental processing Images and illustrations are examples. Colors, symbols, designs and information on the depicted labels and/or packaging may differ from reality.

Dental processing – Frame production and ceramic veneering Model making and coping fabrication 1 Model making The model forms the basis for all work at the dental laboratory! The more carefully it is made, the more precisely crowns and bridges will fit. The BegoStone plus super-hard plaster is used to make the master model/saw-cut model. Process steps • Step 1: The impressions received from the dentist must be cleaned, disinfected and rinsed out with water. • Step 2: Before casting, carefully dry the impression with compressed air. Any water left on the impression may result in different strength...

Dental processing – Frame production and ceramic veneering Modelling: Copings made from wax As an alternative to the Adapta deep drawing system, copings made from wax can be produced using the wax dipping technique. For the cement line, it is necessary to apply spacer varnish instead of spacer foil. The working temperature of BEGO dipping wax is approx. 75 °C. The crown margin of the dipped coping is completed with cervical wax. During wax-up sufficient space must be provided for subsequent ceramic veneering. The metal frame should support the ceramic veneering from the inside and ideally have...

Dental processing – Frame production and ceramic veneering Compensating for missing tooth substance If the tooth stump is too small, the missing substance is built up in metal as this is the only way to guarantee that the frame/ceramic layer thickness is as even as possible. Alternatively, there is the option of already carefully blocking out or building up the tooth stump. If the tooth stump is too small, the missing substance is built up in metal Where missing substance requires the tooth stump to be built up, this is the task of the dentist. If it is built up on the master model, this will...

Dental processing – Frame production and ceramic veneering Sprue system 1 With single crowns and bridges sprues are waxed at an angle of 45° between the cast object and distribution channel. After fitting on the mould former, the crowns are located outside the centre of heat, close to the wall of the mould, and can cool down first after casting. The distribution channel should be approx. 2 mm longer than the bridge on each side. Overall, it must be ensured that the restoration is located outside the heat centre. Slender parts should be positioned at the edge of the mould as far as possible. This...

Dental processing – Frame production and ceramic veneering 1 Attaching the sprues To avoid cavities, it is recommended to also supply single crowns indirectly. The sprues should be 4 mm wide and must not taper. A wax wire approx. 2–3 mm in length and 2.5 mm in width is required here for connection to the crown. With bridges, a distribution channel 5 mm in diameter should be provided. Besides wax wires, it is also possible to use hollow sticks with side openings which can be closed with wax. If solid plastic sticks are used, they should be covered with wax as the mould may otherwise tear during...

Dental processing – Frame production and ceramic veneering Investing 1 Selection of investment material When it comes to investing the wax-up, BEGO offers a range of investment materials such as Bellavest ® SH or BellaStar XL which are innovative and have also proved their worth over many years. Mixing liquids which are exactly matched to the type of investment material reliably control the required degree of expansion, so ensuring outstanding casting results with all precious-metal or non-precious alloys. Our product recommendation Bellavest® SH Rapidly or conventionally heatable, phosphate-bonded...

Bellavest®SH / DR Bellavest® T BellaStar XL Bellasun Detailed information about processing investment materials for crowns and bridges can be found from page 36 forwards. Images and illustrations are examples; colours, symbols, designs and information on the depicted labels and/or packaging may differ from reality.

Dental processing - Frame production and ceramic veneering Preheating The preheating temperatures for Wirobond® and Wiron® alloys are 850-950 °C, depending on the casting unit used. Exception: The preheating temperature for Wiron® light is 780-830 °C! Moulds in the sizes 1-6 made from Bellavest® SH/DR or BellaStar XL can be heated rapidly. Roughen mould surfaces, place moulds upright in the furnace (funnel former facing down) without direct contact with the floor or walls (use spacer or ceramic plate, see image to the right). • 20-30 min after the start of mixing place the moulds in the furnace...

Dental processing – Frame production and ceramic veneering Melting and casting 1 Always use ceramic crucibles for non-precious alloys. Never melt different alloys in the same ceramic crucible. Always mark crucibles so that they cannot be mixed up. When casting with an open flame, the crucibles are placed with the moulds in the furnace and preheated. Note Graphite crucibles or inserts should never be used for non-precious alloys: Do not overheat alloy when melting, keep to specified casting times without fail! Alloy quantity The quantity required is calculated by multiplying the weight of the...