Occlusion and the single denture

Occlusion and the single denture

Complete dentures Occlusion and the single Kenneth D. Rudd, Colonel, USAF (DC)** Wilford Hall USAF Medical Lackl,and AFB, Texas denture USAF (D...

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Complete dentures

Occlusion

and

the

single

Kenneth D. Rudd, Colonel, USAF (DC)** Wilford Hall USAF Medical Lackl,and AFB, Texas

denture

USAF (DC),*

and

Center, Aerospace

Robert Medical

M. Morrow,

Colonel,

Division,

A

n especially difficult treatment problenr exists when a dentist finds it necessary to construct a complete denture that is opposed by natural teeth. Malposed, supraerupted, and missing teeth complicate the achievement of a harmonious occlusion for the proposed restoration. The resultant effects, in addition to the inherent unfavorable leverages that develop when natural teeth oppose a complete dcnture~ promote poor stability and retention, as well as early failure of the prosthesis am! concomitant patient dissatisfaction. Meyer’-” developed the concept of the functionally generated path for compietc dentures in an attempt to minimize the effects of negative factors, and to overcome the deficiencies of articulators. This concept, which is still valid, is the basis of currently used functionally g-enerated-path techniques. The research of Pankey, Manrl and Schuyler. as vvrll as the introduction of both new and irnproved materials and technology, have extended the prosthodontic applications of the functionally generated-path concept, particularly for complete dentures. The purpose of this article is to describe a method of constructing complete dentures that are opposed by natural teeth or a reconstructed dentition. This method permits the construction of a duplicate denture with minimal additional time and material. The use of newer materials and techniques simplifies the procedure. INDICATIONS

AND

CONTRAINDICATIONS

The prime indication for the method is the restoration of an edentulous arch that is opposed by natural teeth. Generally, the denture is constructed for edentulous maxillae opposed by a dentulous or a reconstructed lower dental arch. Among the factors that contribute to successful restorations are favorable edentulous ridge and psychologic conformation. adequate denture space, normal jaw relationship, Read *Director **Chief

4

before

the

of Dental

Academy Services,

of Prosthodontics,

of Denture Wilford Dental

Prosthetics Hall

Service,

USAF Hickman

in Fort Medical AFB,

Lauderdale, Center, Hawaii.

Fla.,

Lackland

May, AFB,

1972. Texas.

Volume 30 Numbrr 1

Occlusion

and single denture

5

factors. The method is especially suitable for tooth-supported complete dentures,4 inasmuch as the inherent stability of tooth-supported record bases contributes materially to accurate recording of jaw relationships. The method is contraindicated when the desired jaw movements and the necessary record base stability are not possible, the denture space is inadequate, and the physical or mental condition of the patient seriously compromises effective cooperation. PREREQUISITE

TREATMENT

Thorough examination of the oral cavity, including an adequate radiographic survey, is essential. Prior to construction of the denture, it is desirable to complete all rehabilitation procedures in the opposing dental arch. All restorations, including fixed or removable partial dentures if indicated, should be completed. An acceptable level of oral hygiene, which is mandatory, should include maintenance instructions for both the edentulous arch and the remaining natural teeth. Tissue-conditioning materials or “bubble gum” therapy5 may be indicated for the oral tissues abused by ill-fitting prostheses. Diagnostic casts should be made and examined carefully to identify malposed or supraerupted teeth and to make all corrections required for improving the alignment of the opposing dentition. PROCEDURE Treatment The method to be described is used for an edentulous maxillary jaw opposed by a dentulous mandibular arch. Apfointment I. After all prerequisite procedures have been completed, impressions are made of both jaws. Alginate (irreversible hydrocolloid) impression material is used for making the impression of the opposing dentition. A preliminary and corrected impression is made of the edentulous arch. The corrected impression is boxed, and the casts are made of mechanically spatulated artificial stone. When set, the casts are removed from the impressions, and the posterior palatal seal is established on the maxillary cast. Then the casts are trimmed and indexed. In preparation for the next appointment, two autopolymerizing (cold-curing) resin baseplates are constructed on the maxillary cast. These baseplates should fit the cast accurately and not damage it during removal. A wax occlusion rim is made on one baseplate at this time, and a black modeling-plastic occlusion rim is made on the other baseplate later. Appointment II. A tentative jaw relation record is made, and the casts are mounted in an articulator during the second appointment. The wax occlusion rim is contoured to give the desired lip support and adjusted to establish the desired vertical dimension of occlusion. The centric relation position is recorded with zinc oxide and eugenol paste at the selected vertical dimension of occlusion. Phonetics tests, determination of the existence of adequate interocclusal distance, and esthetics are used as guides in determining the vertical dimension of occlusion. The maxillary cast is mounted in the articulator by means of a face-bow transfer record. (When a duplicate denture is to be made, duplicate casts are mounted in another articulator.) The mandibular cast is positioned in the jaw relation record and mounted in the articulator with slurry-activated dental stone. It is unnecessary for the articulator to

Fig. 1. The modeling-compound do not contact

occlusion

rim

trimmed

so the buccal

and lingual

cusp tip:

it.

Fig. 2. An indentation is made in the compound relation can be maintained.

rim as :L reference

point

so that the xertlcz.

be fully adjustable, because only the hinge opening movement is used. Denture teeth are selected and positioned with the patient present. Thereby, the best esthetic and functional result can be obtamed by varying shades, molds, and positions. This procedure is so important that the dentist should not delegate it to a laborator): tec,hnician. If an auxiliary denture is to be provided, the same procedure is followed (111 the duplicate casts. The setup is completed for try-in at the next appointment and removed from the cast. The duplicate baseplate is placed on the cast, and a black modeling-plastil occlusion rim is constructed. The modelinq i plastic is warmed and adapted to the’ baseplate, and the articulator is closed so indentations are formed in the warn! modeling plastic by the opposing cast. When cool, the occlusion rim is trimmed until the space between it and the mandibular anterior teeth measures 2 mm. The posteriors quadrants of the occlusion rim are trimmed until the buccal and lingual cusps c)i the mandibular teeth do not touch the occlusion rim (Fig. 1 1. ‘The occlusai \,erticA dimension is maintained by extending the lrlodelirlg-plastic ridge into the central s&i of the opposing mandibular teeth. The occlusion rim should br approximatei! twice as wide as the buccolingual width of the ruolar teeth, and it should extend 6 mm. anterior to the mandibular incisor teeth. LVith the modeling-plastic occlusion rim in position and both the cast and articulator closed, dividers are used to make a vertical-dimension reference measuremerit (Fig. 2). One point of the dividers is placed on an easily identifiable Iandmarh on the cast, such as the gingival margin on ;I tooth, and the other point. is used :o indent the modeling-plastic occlusion rim. This measurement is recorded so that. it will be readily available in the event that the adjustment of the dividers is inad, vertently changed. This measurement is used as a ~cruide in evaluating L the occinsaI vertical dimension throughout the functionally generated-path procedure. NOM thi. modeling-plastic occlusion rim and the waxed denture are ready for the :le:tt appointment. Appointment 111. The waxed denture is inserted and subjected to the usual

Fig. 3. A plastic the separation procedures.

strip around of the recording

the labial and buccal surfaces of the occlusion rim prevents wax from the compound occlusion rim during the “chew-in”

Fig. 4. The generated wax path is boxed, and minimal-expansion it. This forms the generated-path stone core.

artificial

stone is poured

in

checks made during a try-in appointment. The duplicate denture is evaluated in the same manner during this appointment. The esthetic effect and the accuracy of the jaw relation record are evaluated, and indicated changes are made. The wax denture is removed, and the baseplate with its compound occlusion rim is inserted. The accuracy of the tentative jaw relation record is verified, and if correction is neccssary, a new record is made and transferred to the articulator. However, if the tentative record is correct, the compound occlusion rim is removed and dried with an air syringe. Recording wax* for the functionally generated-path procedure is added to the occlusion rim, and both are tempered for 10 to 15 seconds, first in water at room temperature and then in water at 120° F. A strip of thin plastic is sealed to the outer surface of the occlusion rim to prevent separation of the wax from the occlusion rim during functional movements (Fig. 3). The wax is flowed onto the rim, and care is taken to keep the hot wax spatula from coming into contact with the compound sulcus ridge. Wax is added until it is level with the height of thr sulci ridges. After the modeling-compound occlusion rim, with the recording wax added on the occlusal surface, has been placed in the mouth, a closure in the centric relation position is made by the patient. While the patient maintains this gentle contact, the dentist checks the occlusal vertical dimension against the previously recorded reference measurement. Several cycles of removal, tempering, and jaw closure may be needed to re-establish the desired vertical dimension of occlusion. No eccentric excursions are attempted until the vertical dimension of occlusion has been re-established. The first simulated functional movement recorded in the wax is in the protrusive excursion, and the recording sequence is from the rctruded position toward the protrusive position, approximately 6 mm. anterior to the posterior position. For making recordings, the movements should be from the retruded position toward the eccentric position. Other directions of movement do not produce good results. *The recording wax is prepared by melting three sheets of medium-hard, wax and two sheets of red counter wax (J. Bird Moyer Company, Philadelphia, water and allowing the resultant mixture to cool.

pink baseplate Pa.) in boiling

Fig. 5. An impression of the stone core is made in an RTV silicone impression material Fig. 6. The impression of the stone core is boxed. and artificial stone is poured into it on 1 second articulator.

Usually, it is necessary to repeat the movement path. The lateral excursive paths are recorded in one lateral excursion and then the other. When centric closure is made and observed closely to contacts which indicate inaccurate records. If the able, the occlusal vertical dimension is checked mouth. The stone

sequence to form the protrusive wax in the same manner, i.e., first each pathway has been formed, :i locate possible deflective occlusal wax denture is esthetically acceptagain prior to removal from tlrc

core

The completed wax-path record is placed on the master cast, and the opposing cast is removed from the articulator. The generated wax path is carefully boxed and vacuum-spatulated, minimal-expansion stone is poured into it (Fig. 41. This forms the stone core which is attached to the articulator. After the stone has set, the wax is cleaned from the stone core, and the baseplate and modeling-compound occlusion rim are removed from the cast. The wax denture is placed on the cast, and its occlusal contact with the stone core is carefully examined. The upper denture teeth are set or ground to fit tht generated path as recorded in the stone core. A nontoxic, water-soluble pigment” is used as an indicator, and the denture teeth that contact the core prematurely art: recontoured until all teeth make contact with the core at the same time. When denture teeth fail to contact the core, they are repositioned so they make adequate contact. However, in some patients who have a deep vertical overlap in the natural teeth, esthetic and phonetic considerations may contraindicate a reduction of the overlap just to avoid a protrusive interference. It may be necessary to cut away some of the stone core in the anterior region so the posterior teeth call contact the core. Duplicate When

denture a duplicate

second articulator. *Ultramarine

denturr

is required,

An impression blue, Becour Artist

the

stone

core

must

be reproduced

of the stone core is made in an RTV Colors, Inc., New York, N. Y.

on :a

(room tem-

zxe? “P

Occlusion

Fig. 7. The original

and single

denture

(left) and duplicate dentures (right) are ready for the patient. occlusal surfaces are used to prevent excessive abrasion of the opposing natural teeth.

9

The gold

perature vulcanizing) silicone impression material* (Fig. 5) and luted to the baseplate with a mix of slurry-activated artificial stone (Fig. 6). When set, the baseplate and the silicone impression are transferred to the duplicate cast on the second articulator. The impression is boxed and poured in minimal-expansion stone. After it has set, the impression is separated and removed from the duplicate master cast. The teeth in the duplicate denture are fitted to the stone core in the manner described previously. If dentures are opposed by natural teeth, metal occlusal surfaces may be necessary. They can be constructed to conform to the shape of the stone core.G When the occlusion has been fitted to the stone generated-path core, the dentures are ready for final try-in. Apflointment IV. The waxed dentures are subjected to all checks associated with the try-in appointment. The centric and eccentric occlusions are evaluated. The patient’s acceptance of the esthetic result is obtained before processing. The wax dentures are placed in the articulators, and the occlusion is rechecked prior to flasking. The dentures are flasked, boiled out, and processed in the usual manner. After the dentures are cured, they are cooled in the flasks. Then they are deflasked and returned to the articulators. Careful flasking and packing greatly minimize the “processing error.“’ Any increase in the vertical dimension of occlusion after processing should be eliminated by using nontoxic, water-soluble pigment to guide the selective grinding of the teeth. Then the dentures are polished (Fig. 7). Appointment V. The complete dentures are inserted, and the usual procedures associated with the insertion appointment are carried out. Smooth lateral and protrusive occlusal excursions without deflective occlusal contacts should characterize the functionally generated-path occlusion. SUMMARY A technique for constructing dentures opposed by natural teeth is described. The method uses the functionally generated-path technique for developing the occlusion. *Silastic

388 Denture

Release, Dow-Corning

Corp., Midland,

Mich.

10

Rudd

and Morrow

The method provides a means for making duplicate dentures with minimal aciditionz’ time and cost. The clinical and laboratory procedures are essentially the same as
The functionally generated-path technique is indicated for complete opposed by natural or reconstructed teeth. Although the method differs usual approach to denture construction, it can be easily mastered.

denture\ from the

References 1. Meyer, F. S.: Building Full Upper or Lower Artificial Dentures to Opposing Natural Teeth. North-West Dent. 30: 112-l 16, 1951. 2. Meyer, F. S.: Dentures---Causes of Failures and Remedies, J, PKOSTHE.~. DEXT. 1: 67Li691, 1951. 3. Meyer, F. S.: The Generated Path Technique in Reconstruction Dentistry. Part V, J. PROSTHE?.. DENT. 9: 354-366, 19.59. 4. Morrow, R. M., Powell, J. M., J ameson, W. S., ,Jewson. P. G., and Rudd, K. D.: TonthSupported Complete Dentures: Description and Clinical Evaluation of a Simplified Technique, J. PROSTHET. DENT. 22: 414-424, 1969. 5. Morrow, R. M., Feldmann, E. E., Rudd, K. D., and Trovillion, H. M.: Tooth-Supportrd Complete Dentures: An Approach to Preventive Prosthodontics. J. PROSTHET. DESI‘. 21: 513-522, 1969. 6. Koehne, C. L:, and Morrow, R. M.: Construction of Denture Teeth With Grlld Occlu~al Surfaces, J. PROSTHET. DENY. 23: 449-455, 1970. 7. Rudd, K. D.: Processing Complete Dentures Without Tooth Movement, Dent. Clin. North Am., Nov., 1964, pp. 675-691, COLONEL Ruon 6005 RUE LILIANE SAX ANTONIO, TEXAS COLONEL

78238

MORROW

CMR 3, Box 5841 APO SAN FRANCISCO

96553