July 3, 2018
by Viviane Haber, DDS
A variety of methods have been introduced to maintain veneer preparation integrity, tissue health, and overall patient comfort. While there are many approaches to the temporization process, both indirect and indirect-direct, one of the most efficient is the direct method. Most procedures involve indirect temporizing techniques, fabricating and polishing the provisional outside of the mouth on a diagnostic cast, and intraoral cementation with non-eugenol cements. The indirect-direct method provides the best of both, but also combines their weaknesses, including sacrificing efficiency. The indirect-direct concept is a sound one; it involves relining the intaglio of the shell made outside of the mouth. If it fails, however, the practitioner must fall back onto the direct or indirect method, dependent on time available and casts made. The direct inside-the-mouth technique allows the dentist to produce temporary restorations in a fast, and efficient manner.
The primary purpose of the temporary restoration is to assist the patient’s acclimation to the look and feel of their new smile. This is an important step in the process of smile transformation; the patient has made a commitment to change, has specific expectations and may be fragile or vulnerable during the interim stage. There are many factors to consider during temporary veneers fabrication, including a smile design that has been approved by the patient and the patient’s willingness to make an informed decision about maximizing the esthetics while staying within the parameters of function. These issues are first addressed during the diagnostic wax-up stage, and then completed during the bonding of the final veneers. Aligning expectations with reasonably achievable outcomes is the precursor to preparation (if any) and temporization as this allows the dentist to communicate to the patient how the provisional will look in the mouth prior to fabrication and cementation.
Once the veneer preparations have been completed and a master impression taken, the next step is the temporary fabrication process. Beginning with the diagnostic wax-up, and modified by reasonable patient changes, a putty impression material matrix is created. The matrix must have minimal facial thickness and bulk on the palatal/lingual. The palatal thickness is necessary to allow the matrix to be held firmly in place over the prepared teeth without distorting the temporary veneers. The facial thinness of the matrix is required to not displace the lips excessively, to mimic the anatomy of the wax-up design, and to facilitate the clean-up process, minimizing flash on the lingual.
It is imperative to not etch or place self-etching bonding agents on the preparations as this can modify prepared surfaces of the teeth. Simply place an unfilled adhesive on the preparations, thin it with a gentle blast of air, and cure with the curing light (Fig. 1).
The putty matrix is trimmed with a #25 blade knife, scalloping it about 1-3 mm coronal to the gingival margin, ensuring that the interdental papillae are exposed (Fig. 2). It is essential that the temporary material does not impinge on the soft tissues to maintain proper gingival health for the veneer seating and cementation appointment. The matrix must not touch the facial soft tissues as it this can distort the temporary restoration, as well. It is helpful to place a notch in the matrix between the central incisors for orientation and positioning.
A bisacryl temporary material is dispensed into the putty matrix to fill the facial surface. The filled matrix is inserted into the patient’s mouth (Fig. 3) over the prepared teeth, assuring that the notch aligns to the midline. Holding the filled matrix on the palatal, ensure that there is no pressure on the facial portion that may distort the temporary. As the bisacryl is polymerizing, the excess is quickly wiped with a gauze. A microbrush is inserted through the interproximal areas (Fig. 4) to remove any material that may be impinging on the papillae. The temporary material is allowed to set completely before removing the matrix. Early removal, while the resin is slightly gelatinous, effectively ruins the temporary, destroying the fit or the esthetics (or both), and requiring a remake.
When the temporary material is completely set, the matrix is removed in a peeling motion so as not to displace the provisional on the patient’s teeth. Any excess material on the other teeth, the soft tissues, or in the vestibules is cleaned away (Fig. 5). The entire body of the temporary restorations is now intact, as a single unit. Open margins are revised by placing flowable composite of the same shade as the original bisacryl material at the cervical/gingival portions of the teeth (Fig. 6). The flowable resin must not be allowed to drift onto the soft tissues as it may cause soft tissue irritation. It should also conform anatomically. Finally, the added flowable is cured, and the margins are checked for complete seal to reduce any post-op sensitivity (Fig. 7). The temporary restoration in place and ready for the final polish, eliminating the need for extensive polishing disks, point and cups, and interproximal finishing strips, unless there are gross defects.
An unfilled resin or a composite sealer (smoothing surface irregularities) helps to maintain the temporaries’ shade. A small drop is placed on the provisional and spread around the facial with a microbrush. The liquid is thinned with a cotton sponge or a very slight air spray, and light cured. This “glazing” provides an immediate sheen, allowing patients to “test drive” their new smiles until their final seating. The patient immediately gains confidence, increasing their anticipation for the final veneer cementation. The dentist achieves the personal satisfaction of providing a beautiful smile that actually makes the patient happy even in the provisionalization stage.
The final step is to verify and correct, if necessary, the occlusion. The lingual surfaces of the veneered and adjacent teeth must be cleared of flash (creating artificial hyperocclusion). The ideal incisal contact is a slight tug on the shim stock when threading it through with the natural dentition in maximum intercuspation, but not enough to tear the foil. If there are any high points, they must be identified and removed. The dentist then similarly examines excursive movement occlusal contacts to ensure that the patient can function effectively and comfortably for at least one to two weeks with the temporary restoration. This process, while arduous, is crucial to prevent improper contacts from negatively affecting the occlusal harmony of the teeth. If any marginal defects are found after finalizing the contacts, it is vital to restore all of them to maximize patient comfort and minimize possibilities of sensitivity and/or decay.
The temporization process is a sequence of relatively simple and well established clinical steps. It is essential that all the steps be completed, and in the correct order. Strict attention to detail is important throughout the entire temporization process as even a minor error can be catastrophic. The direct, intraoral method for provisionalization offers a clinically straightforward, efficient, and effective method for fabricating temporaries that requires fewer steps, greater accuracy, and less chairside time. OH
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About the Author
Dr. Viviane Haber is a 1985 graduate of Loma Linda University. Alongside operating her private practice since graduation, Dr. Haber is an Assistant Professor at Loma Linda where she has been teaching cosmetic dentistry for over 10 years. Dr. Haber is a Diplomate in the American Society for Aesthetic Dentistry.