Diagnostic Wax Up And Mock Up For Dental Treatment Visualization

Introduction

Today, the aim of prosthodontic and restorative dental treatment is to get an expected esthetic results. So, it is important to understand the patient desire and expectations. This can be possible only by communicating with the patient. Any treatment outcome should be known and visualize before any irreversible procedure and that’s done by diagnostic wax up and mock up. (1, 2, 3, 7, 11)

• Diagnostic wax up The diagnostic wax up is defined as a diagnostic procedure of a planned restorations that’s developed with a wax on a study model “diagnostic cast“ to give a 3-D model of teeth built in wax that represent and achieve the desired esthetics and function. (1, 2, 3, 8, 9)
• The diagnostic wax up can help us in:
• Selection of suitable restoration and determine the need for preprosthetic surgery, orthodontic, periodontal or endodontic treatment.
• Assist in estimating the amount of restorative space available and indicate any need for treatment in the opposing arch to create space.
• Any modifications are needed in the remaining dentition.
• Patient education tool, and facilitate the approval of the treatment.
• A guide for radiographic and surgical implant placement.
• Creating a vacuum-formed template or silicone matrix from the wax up as a guide for tooth preparation.

There are differences between the arch of properly positioned teeth wax up, and the arch of malpositioned teeth wax up. The properly positioned teeth can be restored simply by shaping the wax while the remaining teeth act as a guide. But in the other case the remaining teeth may be worn down, malpositioned or supraerupted, and to design the wax up of the teeth to be restored, the correct position of the teeth need to be re-established. The process of making a diagnostic wax up in the previous case may indicate that additional treatment needs to be done first to restore other teeth that interfere with the restorative space, occlusal scheme, or esthetics.

• So the most important function of the diagnostic wax up is to provide diagnostic information that affects the treatment plan. (3)
• The diagnostic wax up can show the predictable result if it possible to do it or not. Like in some cases during the waxing process, it may be determined that the plan cannot be achieved from a functional perspective.

For example, if you are restoring the maxillary arch and increase the vertical dimension, the diagnostic wax up may show that there is no longer anterior contact between the upper and lower anterior teeth. So the anterior veneers that you had planned or that the patient requested will not work in this situation, because you will need to add ceramic on the palatal surface of the upper teeth to reestablish contact with the lower anterior teeth to achieve the desired function. This will change the plan from restoring the teeth with veneers to using crown restorations on the maxillary anterior teeth, or doing additional procedures on the mandibular anterior teeth to establish contact. (9) The communication between the clinician and the technician are very important, to guide the waxing according to these factors: incisal edge position, midline, teeth length, width, and CEJ position. The probable need for soft tissue augmentation is considered and requested as a gingival tissue wax up to evaluate the need for gingivacolored ceramics.

Types of Diagnostic Wax Up

The basic diagnostic wax-up aids in developing an overall game plan for the restorative procedures. Basic diagnostic wax upIt aids in adding minimal amount of wax in the deficient areas only. For example adding wax in the lingual contours to improve anterior guidance functions, and increase the incisal length to achieve the desired length or position. It’s the least costly in both time and money, but it is the best tool for the visualization process.

Full contour wax upIt’s used when improved esthetics and contours are included in the treatment plan, missing teeth are involved and implant placement determinants are needed. This type is the choice for large rehabilitation cases.

The case presentation wax-up is generally requested to show the patient the end result of the personalized treatment plan.

Case presentation wax upIt’s used to show the patient the result of the personalized treatment plan. And requires much more skill and time from the technician or laboratory assistant, which is reflected in the cost.

The orthodontic wax-up helps visualize the possibilities available when repositioning is an integral part of obtaining optimal results on a given case.

Orthodontic wax upIt helps the practitioner to know the possibilities available when repositioning is an integral part of obtaining best results on a given case. Teeth can be placed in the proper position to achieve the fundamentals of occlusal stability. The cost of this type is often well worth the time and money spent. (8)

Diagnostic mock up: It is a preparation that displays the result over the unprepared teeth. It serves as a guide in prosthodontic treatment. This procedure allows the clinician to apply tooth-colored filling materials, like composite, to temporarily improve the shape and form of teeth. This mock up procedure can be done before or after the diagnostic wax up. (2, 3, 4, 6, 7)

Mock up material and technique: The flowable composite is the material of choice. It is easy to apply, flows quickly and sets with a smooth, esthetically pleasing appearance. Regular composite was used originally but because the tendency of this composite to lift off of surfaces as it is shaped, it was replaced with flowable which remains in place. It can be applied directly on the natural teeth or as a thin veneer over diagnostic cast. After tooth reduction, the flowable composite can be layered into any desired thickness. To shape the interproximal and gingival areas, a fine bladed carver can be used. After light curing a finishing bur is needed for shaping. (6)

Types of Diagnostic Mock ups

1. Preliminary diagnostic mock up

Composite resin is used to contour one or more teeth and evaluate the patient’s appearance. This type is done before the diagnostic wax up. Photographs are taken to documenting the new incisal edge position at rest and smile in relation to the lips. After taking an impression, the information is gathered and sent to the laboratory to create a diagnostic wax up that follows the teeth that were built in the mock up and extend it to the remaining teeth.

2. Secondary diagnostic mock up

This mock up is referred to as overlay prosthesis, is done after the diagnostic wax up has been made. It is formed by using a silicone matrix filled with autopolymerizing resin, placed the matrix over the natural teeth and removed upon final polymerization.

3. Removable mock up provisional restoration

This type is designed to be removed intact, it can be used as a removable overlay prosthesis for the patient to wear over the teeth. This mock up is used until the final approval of the teeth arrangement is obtained.

4. Fixed mock up provisional restoration

This mock up is used as a preliminary fixed provisional restoration. (3, 6)

Conventional and Digital: In the study of “Morphological Symmetry of Maxillary Anterior Teeth before and after Prosthodontic Planning”, they compare between conventional wax up and digital wax up. The aim of the study was to evaluate the effect of different prosthodontic planning methods on the morphological symmetry of maxillary anterior teeth. The asymmetry was evaluated at two levels:

1. Tooth morphological asymmetry (TMA): the superimposition of the labial surface of each anterior tooth with the contralateral tooth on a mirror image.
2. Anterior segment morphological asymmetry (ASMA): The superimposition of the combined labial surface of all the anterior teeth with the combined labial surface of the contralateral side on the mirror image.

Results

The digital wax up models had significantly less asymmetry (p < 0. 00) than the conventional wax up models in the TMA level. However, at the ASMA level, the difference was insignificant (p > 0. 05). (13) In other study, “Digital smile design and mock up technique for esthetic treatment planning” shows that the combination of the two techniques (Digital smile design, conventional mock up) can offer improved esthetic manipulation, a better predictable model to support the treatment plan and increasing the patient expectation satisfaction. (5)

· Case report a 25 year old female patient presenting to Ordu University, Dentistry Faculty, Restorative Dental Treatment Clinics with an aesthetic problem (malformation in the tooth number 21) The patient didn’t accept the orthodontic treatment, because of the long period of the treatment, and also rejected prosthetic treatment because of its high costs, it was decided that direct composite restoration is the treatment for this patient by using the Composite mock up technique.

Conclusion

A diagnostic mock up is an important communication tool to help patients in visualizing the future result. It also facilitates a two things: one from the patient to express his or her desire regarding the future outcome, and the other one from the dentist to verify the contours of the restorations and explain the limitations. Therefore, avoiding the frustration that may result from miscommunication. The diagnostic mock up is a simple and fast procedure that can enhance the satisfaction of both patient and dentist significantly. (2, 3, 5, 7) An important concept is to obtain clinical information to guide the diagnostic wax up. This method will improve the predictability of the treatment, minimize the chair time, and help to get patient agreement from the beginning of treatment. (3)