Definition: Attaching maxillary and mandibular casts to an articulator in their recorded jaw relation.
Also called articulation.
Maxillary cast articulated first, then mandibular cast after recording vertical and centric jaw relations.
Types:
Arbitrary mounting
Mounting using face bow
Zeroing/Resetting Articulator
Mean Value Articulator (Class II):
Clean articulator.
Movable surfaces should move freely.
Incisal pin flushed with the top of the upper member for zero reading.
Mounting table properly fixed.
Semi-Adjustable Articulator (Class III):
Clean articulator.
Movable surfaces should move freely.
Incisal pin flushed with the top of the upper member for zero reading.
Incisal guide table at 0° antero-posteriorly and laterally.
Condylar track at 30° bilaterally.
Bennett angle at 30°.
Lateral condylar guidance at 15°.
Lock the opening axis (hinge axis) into centric position.
Needed records:
Centric occlusal record - vertical record
Protrusive record - Lateral condylar angle comes from the equation L=12
Face bow record
Uses:
Can produce opening & closing
Can produce protrusive and lateral (eccentric) movements
Casts Preparation for Mounting
Determine the midline using the incisive papilla.
Place casts in slurry water.
Create 3-4 V-shape cuts on the base of casts (1/4 inch depth and 1/2 inch width).
Lightly coat the base with Vaseline or separating medium.
Seal the base plate with occlusion rim to the cast using wax.
Mounting the Maxillary Cast
Attach the maxillary cast first using face-bow (adjustable articulators) or mounting table (mean value articulator).
Ensure enough space between the base of the cast and the upper member of the articulator.
Align the midline of the maxillary occlusion rim to the center of the cross midline on the mounting table.
Mix plaster and pour over the base of the cast, closing the upper member until the incisal pin touches the incisal table.
Smooth and polish the plaster.
Mounting the Mandibular Cast
Mount after recording tentative vertical and centric jaw relations.
Secure the mandibular occlusion rim to the cast with wax, sealing between maxillary and mandibular rims.
Ensure no posterior interference.
Invert the articulator with the mounted maxillary cast.
Place the maxillary occlusal rim with mandibular occlusal rim (centric record) on the maxillary cast.
Place the mandibular cast on the mandibular occlusal rim (after soaking in slurry water).
Mix and pour plaster over the base of the mandibular cast, closing the articulator until the incisal table touches the incisal pin.
Smooth and polish the plaster.
Checking the Mounting
The midline of maxillary cast should be coincided with the midline of mandibular cast and midline of articulator.
Centralization of maxillary cast with upper member of articulator then the centralization of lower cast which depend on accuracy of the maxillary cast.
Incisal pin checked if it does not touch the incisal table.
Possible Errors During Mounting
The record base is not properly secured to the cast.
Interference of the casts posteriorly.
The incisal pin does not touch the incisal table.
The incisal pin is not properly screwed.
Wrong transference of the midline of the articulator with that of the casts (shifting of the midline).
Movement of the casts during mounting.
Maxillary & mandibular rims are not properly fixed after making centric record.
Dimensional changes in the plaster material.
Improper Record Base Attachment
Inaccurate tongue space in the final denture.
Discomfort during speech.
Difficulty in swallowing.
Poor adaptation of the denture in the oral cavity.