(c) Cleans the instruments used to prepare the impression material
before the material hardens on these instruments.
(d) Cleans any material from the patient's face and mouth after the
impression has been removed. Oil of orange or oil of lemon is a good solvent for
removing zinc oxide and eugenol impression pastes and rubber-base materials.
(e) Cares for the resulting impression by carefully handling the
impression to avoid distortion or damage to tissue and peripheral areas of the
(f) Washes the impression with cool water or cool slurry water (a
solution of water and artificial stone or plaster of Paris) to remove saliva.
(g) Pours the master cast from which the complete denture is to be
fabricated, if a dental laboratory specialist is not assigned to the clinic. Cast pouring
procedures are described in TC 8-226, Dental Laboratory Specialist.
The local SOP at each facility will describe exactly what must be done by the
JAW RELATIONSHIP RECORDS IN COMPLETE DENTURE FABRICATION
Three types of jaw relationships will be discussed--centric jaw relationship,
maxillo-temporomandibular joint relationship, and lateral and protrusive relationship.
a. Centric Jaw Relationship. When final casts have been obtained and
occlusion rims or trial bases fabricated, the next procedure is to determine the correct
positional relationship of the maxillary cast to the mandibular cast for setting the denture
teeth and establishing occlusion. Determinations are usually made and recorded in the
mouth by using occlusion rims and one of the following materials--modeling plastic,
plaster of Paris, or softened wax. A needle point-tracer (the gothic arch tracer) may
also be used for this record (see figure 5-13). The recordings and occlusion rims are
then transferred to the casts for mounting on the articulator.
b. Maxillo-Temporomandibular Joint Relationships. The prosthodontist may
also record the relationship existing between the maxillae and the opening and closing
axis of the temporomandibular joint. This registration is used to mount the maxillary
cast on the articulator in the same relationship to the hinge axis of the articulator as the
patient's maxillae to the temporomandibular joint. A face-bow registration is used to
record this relation.