Indice. Instruduction Practical use...3 Model and die preparation...3 Metal coping...3

Transcription

1 Press to Metal low fuse porcelain instruction manual

2 Indice. 1 Instruduction.2 Practical use....3 Model and die preparation...3 Metal coping...3 Opaque 3 Wax Build up...3 Sprue design..3 Investment...4 Wax burn out Pressing cycle...5 Investment removal 5-6 Sprue cut.7 Incisal cut and finishing 7 Porcelain build up 8 Porcelain bake..8 Margin check and polishing...9 Stain and glaze Examples Color combination table Firing chart Opaque firing chart 14 Troubleshooting....15

3 2 The needs of dental laboratories to decrease production time while maintaining natural esthetics and accurate fit have led to the development of this new material enabling the technician to produce restorations meeting these criteria. Our press to metal ceramic tablets offer both to the specialist and the beginner a product capable of replicating the look and beauty of natural teeth bith quickly and accurately. Indications and contraindications The product and technique are designed for use on single units to three unit bridges over a metal substructure. The material can also be used for inlays, onlays and veneers. The Alloy Most alloys suitable for PFM are compatible with the porcelain. The recommended CTE for the alloy is 13.8 to 14.4 x / C at C.

4 Ceratec LF Press over Metal 3 Model The model is prepared in the normal manner. Metal coping Sandblast and oxidize the coping according to the manufacturer s s instructions. Opaque the coping in the normal manner. Using either one coat of Ceratec Mask opaque and one coat of the desired shade or two coats of the prescribed shade. Weigh the opaqued coping after completing the process and record the result (W1) CAUTION: Use only Ceratec opaque powders as the LF Press Tab and the technique are designed specifically for use with this opaque. Other opaques may run or degrade in CTE during the process resulting in poor esthetics or a failure of the t restoration Wax Up Wax the complete restoration and then do an incisal cut if desired. ed. The restoration must be modeled with a minimum thickness of 0.8mm. CAUTION: use only wax free of ash residue. Sprues The recommend length for the sprue is mm and 3.5mm in diameter. They should be attached to the most voluminous part of the crown. Crowns on the occlusal or incisal and inlays in the proximal. The connections must be rounded and the crown to be injected should form a line with the sprue,, putting this toward the center with a slight incline outwards. When several objects are injected they should be at the same height. Finally, weigh the entire waxed and sprued crown and record this value (W2).

5 4 Investment CAUTION: use only investment recommended for press over metal. Investing is done following the investment manufacturer s s instructions, especially using the recommended powder/liquid ratio. Be sure to vibrate during the process to prevent possible air bubbles. bbles. 100g or 200g rings may be used depending on the number of crowns to be pressed. For three units bridges, the 200g ring is recommended. Note: For best results, press crowns and inlays in different rings. Burn out Follow the investment manufacturer s s instructions. Make sure that the pressable furnace is located close to the burn out oven.

6 5 Proper number of Press Tabs Follow the following steps to select the minimum amount of ingots s needed. Obtain the total wax used by subtracting the weight of the metal coping from the weight of the whole restoration including the metal coping, waxed restoration ration and sprues : W2-W1 W1 Porcelain ingots needed= wax value (W2-W1) W1) X 1.2 The result MUST be rounded UP to the nearest higher number. Thus if the value is 1.2 or 1.8, you will use two ingots. Pressing Preheat plunger in the same oven during the burn out. Do not preheat the Press Tab. Remove the ring from the burnout and place into the pressing furnace. Quickly Q place the plunger and the Press Tab and the pressing cycle. Pressing program: Entry temp. Heat rate Final temp. Hold Re Press s Cooling 1400ºF F 80ºF/min 1450ºF F 7:00min 8:00min ºC C 44ºC/min 788ºC Pressing pressure: 4.5 bars Once the pressing is complete, allow the ring to cool down to room om temperature. Mark with a red pen using the plunger as a guide.

7 6 Divesting Use a saw or a disc for cutting the investment. Then, using a metal spatula, separate into two pieces. Use a fine grain aluminum oxide of 110 microns. Use 3.5 bar pressure until the restoration can be seen. Reduce the t pressure to 2 bar and continue with the sandblasting process. Remove all of the investment from the restoration. CAUTION: When pressing inlays, it is recommendable to sandblast with 50 micron glass beads.

8 Cut Off 7 Cut off the sprue with a diamond disc. First: trace a slight path with the diamond disc around the part you are going to cut. Second: start cutting from only one side and continue to cut through the sprue. Do not do this cut close the restoration. CAUTION: Use a wet foam to remove heat from the process to prevent breakage of the restoration Finishing Remove excess porcelain with a stone and prepare the incisal cut if desired. Finish using a diamond at low speed over the surface of the restoration, also being sure to remove any remaining the investment. Wash using ultrasonic or steam but do not use soap or detergents.

9 8 Porcelain build up If an incisal cut back has been done and incisal porcelain is to be added, or if any dentine correction is necessary, use only Ceratec low fuse veneering porcelain. Fire the veneering porcelain according the firing chart. See the Color Combination Table for recommended incisals

10 9 Check margins and make corrections with nusing a diamond bu.. Glazing: Clean the restoration prior to glaze application. Use only Ceratec low fuse glaze powder or spray (recommended). Use Ceatec stains if desired for shade adjustment or characterization. It is recommend to stain and then glaze in two bakes, allowing the t glaze to protect the stains during the life of the restoration.,

11 10 Crown ready without glazing. Crown ready with stain and glaze.

12 Other cases 11

13 12 COLOR COMBINATION TABLE Opaque CERATEC A0 A1 A2 A3 A3.5 A4 B0 B1 B2 LF Press Tabs A0 A1 A2 A3 A3.5 A4 B0 B1 B2 LOW FUSE INCISAL Clear Clear Extra Light Light Light Dark Clear Clear Extra Light Opaque CERATEC B3 B4 C1 C2 C3 C4 D2 D3 D4 LF Press Tabs B3 B4 C1 C2 C3 C4 D2 D3 D4 LOW FUSE INCISAL Light Light Light Medium Medium Dark Clear Extra Light Light

14 VENEERING PORCELAIN FIRING CHART 13 Dentines and Incisals Dry out Heat rate Vacuum starts Vacuum stops Firing temperature Hold time Cool time 5:00min 65ºF/min 700ºF 1470ºF 1470ºF 1:30 min 0:00 min 36ºC/min 371ºC 799ºC 799ºC Glaze and Stains Dry out Heat rate Vacuum starts Vacuum stops Firing temperature Hold time Cool time 5:00min 100ºF/min No vacuum No vacuum 1470ºF 0:15 min 0:00 min 56ºC/min 799ºC

15 14 Opaque firing chart FIRING CHART Palette Paste Opaque powder Dry out 7 min 3-5 min Insertion 482 C 593 C 900 F 1100 F Heat rate 50 C 50 C / min. 90 F 90 F Vacuum start Vacuum stop Firing temperature 482 C 593 C 900 F 1100 F 954 C - 966ºC 954 C - 966ºC 1750 F ºF 1750 F ºF 960 C - 971ºC 960 C - 971ºC 1760 F ºF 1760 F ºF Hold time 0 0 Cool time 0 0 Final texture of the oapque Egg shell -glossy Egg shell -glossy Thikcness (approx) mm mm

16 Problem Cylinder is broken after injection Injection is not completed Causes Check powder/liquid ratio Check the alignment between the cylinder and plug before starting the process. Not enough Press Tabs Low furnace temperature Low pressing time Solution Follow instructions of manufacturer during the mix of the investment and the liquid. Any variation affects the thermal expansion of the investment creating cracks during and after the process. During the pressing always use the appropriate base for positioning the cylinder in the center of the furnace tray. Check the weight of the wax model and re calculate the number of ingots needed. Check the furnace calibration. Increase final temperature 10-20ºC. Broken ceramic before cutting the sprues. Broken ceramic after cutting the sprues. Stains in the porcelain Fast cool down of the cylinder. High speed cut. Possible contamination with the wax Remove the cylinder after the program is complete and alloow to drop to room temperature before cutting it. Use low speed during cutting and grain fine burs Keep the restoration wet during cutting with the aide of a foam. Use only wax free of ash.