Communicating Lab Needs - A Check List for the Dentist for Optimum Success

by Joe D’Ambrosia CDT
Roe Dental Laboratory, Garfield Hts, Ohio

The successful restoration of large esthetic and reconstructive cases largely depends upon a set of exacting study models, impressions, bites, photographs and explicit instructions. Each has its part to play during the process. The dentist is the “architect” on these cases and the laboratory is the dental “contractor”. Without the right set of “dental blueprints” these cases cannot be completed to everyone’s satisfaction. Without any one of these pieces of information these challenging cases can become more complicated than necessary and the results might be less than expected.

It is a given that the bite, the most challenging registration provided by the dentist, must be correct before any master impressions are taken. Bite registrations are achieved in various manners using TENsing, swallow bites, functional bites, K7 Instrumentation bites (e.g. Chan Scans) and then finally stabilizing the jaw position using a removable and/or a fixed orthotic to determine esthetics and functional occlusion.

In the laboratory we must assume that the bites we receive are accurate unless a “tell-tale sign” alerts us to a possible bite problem in which case the doctor is consulted. The following is a list of “Lab Needs” that you, the dental Architect, must provide for optimum success.

DIAGNOSTIC APPOINTMENT

1.) Provide full arch pre-operative study models capturing peripheral borders, retro-molar pads and hamular notches. Anatomic landmarks are often referenced for mounting, plane of occlusion and tooth position.

2.) Provide full face (no lip retraction) photographs showing the relationship of the upper incisal edges to the lower lip line. Capture the patient’s entire head from slightly above the hair to slightly below the chin. This pose allows us to determine an accurate midline, the long axis and middle of the face, and the horizontal plane of the anterior teeth.

3.) Fox Plane Occlusal Registration (suggested) or a Facebow registration to determine the anatomically correct maxillary cast orientation.*

4.) Accurate, verified bite. Indicate if the bite registration is a Neuromuscular bite, Centric Relation bite or a Centric Occlusion bite registration.

5.) Fill out the lab Rx describing the desired anterior incisal edge length, A-P position, shape of teeth (smile guide photos are helpful). Indicate if the Golden Proportion formula for tooth length and width should be used and include any other pertinent information regarding the patient's particular needs to achieve the desired result.

PREPARATION APPOINTMENT

1.) Provide accurate upper and lower full arch “current condition” impressions or study models of the patients final adjusted (patient/doctor approved) provisional’s. Do not send the original diagnostic wax-up model since any adjustments to the provisionals made from the diagnostic wax-up will make the wax-up model inaccurate for cross mounting.

2.) Provide an accurate full arch opposing impression or model. The same care should be taken to provide good opposing models as is taken for master models. Distorted opposing models can cause inaccurate mountings and inaccurate occlusion as final laboratory porcelain equilibration will be completed against the opposing model.

3.) Provide a full, face forward, natural smile color photograph (no lip retraction) showing the relationship of the upper provisionalized incisal edges to the lower lip line. Capture the patients’ entire head from slightly above the hair to slightly below the chin. This photo’s allows us to see the midline, the long axis and middle of the face and the horizontal plane of the anterior teeth.

4.) Shade: close-up photograph of an open “lip-retracted” mouth holding the selected shade tabs’ next to the incisal edge of the natural tooth. Include and describe any patient specific shade-mapping instructions.

5.) Stump shade tab for “all ceramic” restorations should be recorded.

6.) Fox Plane or face bow registration.

7.) Send lab Rx with information on type of restoration (alloy type, all ceramic system desired, etc.) indicate bridge or singles, and any esthetic and functional information necessary (it is critical to indicate any changes needed to the study model in order to achieve the final desired result).

* Additional information regarding the Fox Place registration technique is documented in the following website www.claytonchandds.com/articles.php (Chan, C.A.: "A Review of the Clinical Significance of the Occlusal Plane"- It's Effect and Variation on Head Posture, ICCMO Anthology VIII, 2007).

Correspondance to: www.roedentallab.com

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