A Novel Approach to Bridge Fabrication
Laboratory support aids in high esthetics for complicated case
Some patients who have been missing an anterior tooth for many years and desire implant placement will have insufficient soft tissue and bone, which may prove to be a challenge. Loss of tissue also makes providing high-quality esthetics more difficult if the alternative procedure, placement of a three-unit bridge, is performed.
Today, achieving the highest level of esthetics when placing a bridge can be accomplished by using the ovate pontic, as this style of prosthetic appears to emerge from the tissue, more closely mimicking the natural tooth. In some cases, even when using an ovate pontic, a patient’s inadequate soft tissue contour will inhibit a highly esthetic result. A connective tissue graft is one way to augment the soft tissue contour for higher-quality esthetics; however, this can involve multiple appointments for surgery and additional expense and trauma for the patient. An alternative technique is to split the ridge of the soft tissue and create an ovate pontic in the temporary bridge, which will support the tissue during healing and increase the apparent volume of soft tissue around the pontic for optimal esthetics.
As part of the annual Heartland Dental Care Aesthetic Continuum series, this case involved a complicated set of circumstances (Figure 1). The patient had significant existing unesthetic dentistry that required updating. In addition, there was insufficient soft tissue volume where the upper left lateral incisor was congenitally missing, which concerned the patient. Although the treatment plan involved replacement of existing crowns, composites, and a composite bridge, as well as placement of veneers, this article focuses only on the bridge replacement and the simple technique used for creating the soft tissue contours that were necessary to meet the patient’s esthetic goals.
As can be seen on the patient’s radiograph, there was significant bone loss in the edentulous area (Figure 2). The primary issue was not the height of the remaining tissue, but the labial volume. During the treatment planning of the case, a split-ridge technique was applied to create the facial esthetic contours best suited for this patient.
After removing the existing wing bridge and preparing the abutment teeth, the final impression was taken. Laboratory support was provided by Albensi Laboratories (www.albensilab.com). The plan was to fabricate an IPS e.max® (Ivoclar Vivadent, www.ivoclarvivadent.com) pressed to zirconia bridge. The entire bridge design was completed using CAD/CAM technology at the laboratory.
Using a No. 15 scalpel, the blade was inserted into the gingival tissue just to the palatal of the crest of the tissue. The exact position of the incision was based on the degree of tissue insufficiency, the character of the attached gingival tissue, and the amount of gingival contour change desired. Generally, the greater the desired change, the thicker the facial tissue will need to be and the more palatal the incision. A certain depth of tissue is required to allow the development of the ovate pontic site, and extremely thin tissue in relation to bone will reduce the effectiveness of this technique. After incising the tissue several millimeters deep, the ovate pontic site was developed by adding material to the tissue side of the previously formed temporary bridge, based on the desired final contour of the soft tissue. Enough material was added to provide support for the soft tissue, with allowance for 1 to 3 mm of shrinkage during the healing process. The ovate pontic was tucked into the incision to preview the contour.
Once the desired pontic contour was created, this information was transferred to the laboratory. At this stage, rather than taking a direct impression of the tissue, which would not reflect its final contour after healing, it is best to take an index of the actual temporary bridge. In this case, simple bite registration material was extruded into the abutments and onto a flat surface where a transfer impression of the tissue side of the temporary bridge was recorded and sent to the laboratory (Figure 3). Albensi Laboratories incorporated this information onto the previously generated model of the final impression and created a reverse index that was placed onto the abutments. The model was relieved until the index was seated passively.
Three weeks after preparation, the entire case was seated. The tissue had healed beautifully at the exact contour desired (Figure 4), and the ovate pontic created in the permanent bridge fit directly into the tissue without adjustment (Figure 5). Through creative treatment planning, excellent communication with Albensi Laboratories, and meticulous attention to detail, an esthetic final restoration was achieved.
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About the Author
Robert Mongrain, DMD
Broken Arrow, Oklahoma