Specifications for the occlusal aspects of dental restorations

Specifications

for

the occlusal

aspects

of dental

restorations Niles F. Guichet, Anaheim, Calif.

D.D.S.

c‘y

urrently, increased emphasis is being placed on principles of occlusion in prosthetic restorations. A need exists to establish a standard protocol, endorsed by an agency of the American Dental Association, which clearly defines the recommended method by which dentists communicate with the laboratory concerning specifications for fabrication of occlusal aspects of restorations. Such specifications would be useful in curriculum design for training dentists and dental laboratory technicians and would improve dentist-laboratory relations. LABORATORY

SPECIFICATIONS

The folIowing protocol was developed on the philosophy that dentists seeking good laboratory support will give technicans complete specifications for fabrication of occlusal aspects of restorations. Recognizing that the position of maximum intercuspation is of paramount importance, it is the responsibility of the dentist who makes an interocclusal record of centric relation or centric occlusion to mount the mandibular cast. Complete specifications furnished by the dentist to the laboratory for fabrication of occlusal aspects of restoration should include: ( 1) full-arch master casts mounted in an instrument with trimmed dies or dies with margins that are easily identifiable; (2) instructions for adjusting articulator condylar controls (if adjustable) when the restoration is fabricated and records for adjustment of the incisal table; (3) specifications as to which teeth are to bear the load in eccentric bruxing movements; and (4) specification for the class of occlusal anatomy desired and position of maximum intercuspation, as described in another article in this JOURNAL.~ DISCUSSION Mounted casts with trimmed dies. To specify that it is the dentist’s responsibility to mount mandibular casts does not mean that this procedure cannot be delegated to a dental auxiliary. For example, in limited restorative procedures in which sufficient Presented to the Federation of Prosthodontic Organizations Workshop, Rochester, N. Y. Presented to the Pacific Coast Society of Prosthodontists, Coronado, Calif. Presented to the American College of Prosthodontists, Orlando, Fla. 101

102

Guichet

J. Prosthet. January,

Dent. 1976

unprepared teeth are present to accurately index full-arch casts in the position of maximum intercuspation, mounting procedures could certainly be delegated, However, as the restoration becomes more extensive, if the dentist delegates mounting of casts to a dental auxiliary and an error is introduced, the dentist must still assume responsibility for the mounting error. Instructions for adjustment of condylar controls. To specify that the dentist should provide instructions for adjusting condylar controls does not mean that the restoration is to be constructed on a fully adjustable articulator. An example of instructions for adjustment of the condylar controls could be, “Lock the instrument in centric relation throughout the laboratory procedure.” It is the dentist’s responsibility to specify to the technician if he wants consideration given to eccentric factors of occlusion in the laboratory and, if so, to what extent. Dentist-laboratory relations. Currently, most dentists send unmounted casts to the laboratory for fabrication of prosthetic restorations. Restorations are returned to the dentist on unmounted casts. If the occlusion is found to be in error when the restoration is inserted in the patient’s mouth, who is responsible for the error, the dentist or the technician? Such a situation can result in strained dentist-laboratory relations. It is the responsibility of the dentist who makes the centric relation record to mount the mandibular cast. When the restoration is returned on full-arch mounted casts, the dentist has a basis for accurate communication with the laboratory. If the laboratory services are satisfactory and occlusal discrepancies are identified in the mouth, the dentist is confident that the error was not introduced in the laboratory. Then procedures can be re-evaluated to determine the source of error. If the restoration fits the mounted casts but not the mouth, technicians cannot be expected to participate in remakes not attributed to laboratory procedures. In addition, since the dentist prepares dies and mounts the casts, that portion of the laboratory fee charged for cast preparation can be reduced or the technician can utilize the time to improve occlusal aspects of the restoration. The protocol which requires the dentist to mount the mandibular cast gives dentists “laboratory control.” This control of delegated services results in better laboratory work. The laboratory has “dentist control” and fewer problems concerning reduced fees and remakes. Third-party payment. In addition, the proposed protocol for specifications for occlusal aspects of restorations would provide a useful tool for establishing quality standards of occlusal treatment and fee schedules in third-party payment programs. CONCLUSIONS When dentists assume responsibility for mounting mandibular casts and provide technicians with complete specifications for fabrication of occlusal aspects of restorations, they will enjoy improved communications with the laboratory, laboratory control, better laboratory work, and improved dentist-laboratory relations. Reference 1. Guichet,

N. F.:

Classification

320 OLYMPIA PL. ANAHEIM, CALIF. 92806

of Occlusal

Carvings,

J. PROSTHET.

DENT.

35: 97-100,

1976.