DIRECTIONS

DIRECTIONS FOR L.A.K. ARTICULATOR - NO PIN SYSTEM:

• Spray articulator with a silicone release agent.
• Pour prepared side of impression first with die stone. Pour the same mix in the articulator, slightly overfilling it. Invert impression on the articulator while wet.
• Wipe off excess material before it sets up from all sides of the articulator to facilitate removal. Allow to set.
• DO NOT REMOVE impression tray from the articulator. Pour opposing arch impression and articulate the same way. Total setting time depends on type of die stone used. Follow manufacture's recommendations. (We have a 5 minute setting die stone material).
• Remove impression tray. Place the L.A.K. lab knife flat between the stone and rim of the articulator from the lingual (side) at the back of the articulator using a prying and twisting motion. When the seal is broken, move the knife forward until the model can be removed esasily. DO NOT PRY ON THE ARM OF THE ARTICULATOR AS THIS WILL DISTORT IT.
• Cut die(s). Start from the occlusal. Continue cutting buccally and lingually, until you ALMOST cut through the model. LEAVE A VERY SMALL AREA OF STONE UNCUT AND SNAP MODEL APART. This will prevent movement of the dies when reassembled.
• USE A BRISTLE BRUSH AND AIR TO REMOVE DUST FROM THE CUT PORTIONS OF THE DIE(S) AND STONE MODEL.
• TRIM DIES ONLY AROUND MARGINS.
• Reassemble in order in the articulator from one end to the other.
• If the bite is incorrect, remove opposing model from the articulator and trim base. Reset bite, add stone to the articulator and remount.

DIRECTIONS FOR L.A.K. ARTICULATOR - PIN SYSTEM:

• Cut excess impression material from sides of the tray to lay flat.
• Spray articulator with a silicone release agent.
• Mark lines on buccal and lingual areas of the impression for dowel pin alignment.
• Pour working (preparation) side of impression tray first with die stone.
• While die stone is still wet, place pins in the center of marked areas of the impression tray. You can also use the Pindex machine to align the pins.
• Allow to set. We have a die stone that sets in 5 minutes.
• Apply die separator and cover pins.
• Mix die stone and cover pins.
• Place remaining stone material in the same side of the articulator and invert. Slightly overfill to form a solid base to facilitate removal of stone material from the articulator.
• Wipe off excess material while stone is still wet from the sides of the articulator to allow easy removal of the model.
• When stone is set pour other side of the impression and articulator and invert.
• Wipe off excess material while stone is still wet from the sides of the articulator to allow easy removal of the model.
• When inverting do not exert excessive pressure - only enough to close the articulator in its correct position. Overclosure and/or underclosure will cause a spring back action when the impression is removed from the articulator.
• Do not remove the impression from the articulator before pouring both sides.
• Follow ususal procedures for sectioning, trimming of the dies, etc.

*An alternative method of pouring up the models is not to fill the articulator completely with the die stone material in the Posterior area. Leave sufficient space to engage knife under the stone model for easy removal. It is also possible to perform only two pours with this technique. After pinning the prepared side and applying a release agent, you can pour up both sides of the impression and articulator with the same stone material and invert.

TROUBLE SHOOTING - DOUBLE BITE IMPRESSION TRAYS

• They should be morphologically designed to fit the arch correctly without any interferences.
• Test the tray first in the patient's mouth for correct fit.
• A full half arch tray that fits recommended for optimum occlusion.
• Sufficient impression must be used on both sides of the tray to fully capture the teeth and supporting structures.
• The posterior crossbar should adequately clear the 3rd molars, maxillary arch and hamular notch areas without interference upon closure.
• Do not cover the crossbar with impression material on either side to verify closure without interference. Biting on the crossbar will cause distortion (flexing).
• If impression material shows through the buccal and lingual walls of the tray, the impression should be retaken. The previous three points are major causes for improper fitting crowns that exhibit high bite and narrow castings that do not completely seat in the mouth.
• Use the proper type of impression material such as a polyvinyl siloxane or polyether.
• A high durometer material is not necessarily the most optimum choice since you can occasionally experience compression. You need a material with some resiliency that will return to its original state when it is fully set. Rigidity can make removal of the impression difficult when undercuts and periodontally involved conditions exist.
• Always work with an assistant during the impression procedure to help load the tray while you are simultaneously syringing the material around the sulcus and to facilitate guiding the patient in centric occlusion.
• The use of half time setting material to speed up the procedure can sometimes be detrimental, especially if you are using a dual phase technique and working with a difficult patient. Usually the material does not set up simultaneously, and you end up with lamination and a restoration that does not fit the mouth.
• Ask patient to open mouth with a snap. If difficult to remove, use finger and thumb between upper and lower periphery in the mucobuccal fold area to facilitate removal. Do not exert excessive force on handle to remove impression.
• Always make an excellent provisional restoration with proper anatomical contour, marginal integrity, contacts and occlusion. The use of a bisacryl material in a double bite impression tray will give you an excellent provisional. Build up tooth first before preparation.
• Predictable impressioning - the tissues should be healthy.
• Proper tissue management - the preparation should be clearly discernible with well defined smooth margins circumferentially.
• Correct margin replacement - ideally one half the depth of the healthy pocket for esthetics.