Inside Dental Assisting
Mar/Apr 2011, Volume 7, Issue 2
Published by AEGIS Communications
A new impact-resistant, tight-fitting, rubberized urethane chemistry is available for provisional restorations.
Function, including the ability to chew normally and not worry that the provisional will come loose or break.
Esthetics, and in more complex cases, working with the patient for smile design.
Phonetics and awareness of tongue placement and speech requirements, especially in anterior teeth.
Space maintenance and eliminating movement of adjacent and opposing teeth.
Protection of prepared teeth from bacteria and thermal change.
Temporization is a key component in the restorative process, and understanding the primary considerations and perfecting the techniques are essential for success and patient satisfaction. Patients expect comfort and esthetics. The practitioner shares these concerns with a focus on overall treatment planning. The fabrication of provisional restorations is often the domain of the dental assistant, who is also a key partner in communicating with the patient. It is not unusual for patients to be more relaxed talking with the dental assistant than they are with the dentist.
The ideal provisional material is non-irritating, tissue-compatible, impact-resistant, dimensionally stable, and esthetic. It should trim to crisp margins and promote healing of gingival tissues, and it should reliably stay in place for 2 to 6 weeks without coming loose or breaking.
The most commonly used materials for temporization are powder and liquid acrylics (methacrylate resins) and automix bis-acrylic resin materials. Powder and liquid acrylics provide good strength and crisp margins, but they produce considerable heat during curing and shrink, which results in a poor fit and frequent debondings. Allergies to these acrylics are not uncommon. Bis-acrylics provide very good esthetics, but they are brittle, frequently come loose or break, and the margins soften during trimming, which often requires repair with a flowable composite.
In response to the shortcomings of traditional acrylics and bis-acrylics, a new rubberized urethane material has been introduced (Tuff-Temp™, Pulpdent Corporation). By inserting a synthetic rubber molecule into a diurethane dimethacrylate molecule, Pulpdent has developed a new chemistry that is impact-resistant and dimensionally stable. Tuff-Temp provisionals trim to crisp margins, and tissue health is remarkable, even after 4 weeks or more in the mouth. They are tight fitting, rarely come loose or break, and they are suitable for single units, long-span, and long-term provisionals.
Tuff-Temp is ideally suited for full-mouth rehabilitation and smile design. The material allows for modification of the shape of teeth during the temporization phase as well as raising the bite when indicated. The Tuff-Temp kit contains a shade-matching, light-curable add-on resin made from the same rubberized urethane chemistry for these modification purposes.
The technique for Tuff-Temp is essentially the same as that used for bis-acrylics, offering the dentist or dental assistant the convenience of fabricating the provisional chairside.
A preoperative impression is made with a heavy-body impression material. If the patient presents with dentition or restorations intact so that the anatomy desired for the provisional is transferred to the impression, then the impression can serve as the matrix (template or stent) for the provisional restoration. However, if the desired tooth anatomy does not exist in the mouth, and therefore is not in the impression, then a stone model and wax-up is usually required after preparing the teeth. An impression of this diagnostic model will then be used as the matrix for the provisional restoration.
The 50-mL double-barrel Tuff-Temp cartridge is placed in the dispenser gun (a 5-mL double-barrel automix syringe is also available), and the mixing tip is placed on the cartridge. A thin coat of separating medium, such as Wink (Pulpdent), is applied to the inside of the matrix, and the matrix is then filled three quarters full with Tuff-Temp. Only the impression of the teeth to be temporized needs to be filled with Tuff-Temp (Figure 1). Tuff-Temp is tough and fracture-resistant and can be used for a long-span bridge such as the one shown. Wink can also be placed on the teeth.
The matrix is inserted into the mouth and removed after approximately 90 seconds. Tuff-Temp is dual-cure. For those clinicians who use a clear, vinyl polysiloxane matrix and clear tray, the light-cure option can be very convenient and can speed up the procedure considerably (Figure 2). Just tack cure the provisional using a curing light.
At this time, check the provisional restoration for marginal integrity. Remove the provisional from the mouth and remove the oxygen-inhibited layer with alcohol. Some clinicians like to light-cure at this stage for an immediate final set. Proceed with trimming and polishing (Figure 3). Note the perfect margins (Figure 4). Tuff-Temp trims to crisp margins without softening or gumming up. In the event of a void, The Tuff-Temp kit includes Tuff-Temp Add-on, a light-cure color-matc hing flowable resin made from the same rubberized urethane chemistry as Tuff-Temp.
Tuff-Temp Glaze, which is also included in the kit, can now be used to create a high gloss, life-like finish. Apply a generous coat, light-cure, and cement the provisional to place. The margins and esthetics are exceptional (Figure 5), helping to ensure patient satisfaction.
The health of the soft tissue is a paramount concern, especially in those cases where the provisional may be in place for many weeks. Clinicians have commented on the excellent condition of the tissues after removing Tuff-Temp provisionals. The 12-unit Tuff-Temp provisional restoration shown in this case was removed after 4 weeks. Note the excellent condition of the tissues (Figure 6).
Whether temporizing a single unit, a bridge or a complex smile design case, and whether using a matrix made from a preoperative impression or a laboratory-fabricated stone model with diagnostic wax-up, the procedure is straightforward. The advantage of Tuff-Temp’s rubberized urethane chemistry is a strong, impact-resistant, tight-fitting temporary suitable for single units, long-span, and long-term provisional restorations.
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