No Temporary Trend: Robust Growth for Temporization
The market for dental implants is continuing along a strong growth trajectory. According to the American Academy of Implant Dentistry, 3 million Americans have implants, and that number is increasing by 500,000 each year. By 2018, the US dental implant and prosthetic market is projected to reach $6.4 billion. Only 10% of American dentists place implants; however, as technology such as cone-beam computed tomography and intraoral scanners becomes more attainable for general dentists, implants will become more widely available for in-office treatment planning.
Although some implant sites are allowed to heal without the need for temporary restoration, many do require provisionalization. The overall growth in the implant market suggests that the demand for temporary restorations will grow too. Dentists who are provisionalizing implants must choose carefully among the available temporization materials to maximize practice efficiency and patient satisfaction. Three major types of temporization materials are available, each with benefits and drawbacks that must be weighed for every case.
Type of Temporization
Used for temporization for more than 80 years, acrylic is relatively inexpensive, costing about 30 cents per restoration. However, the material comes with a number of issues to consider. It must be hand mixed to the proper consistency, typically taking about 20 minutes. Furthermore, acrylic restorations may require significant chairside time, by having to use carbide burs to make adjustments. Acrylic materials exhibit shrinkage during setting and have a strong odor that may bother some patients. Because an exothermic setting reaction releases a significant amount of heat, care also must be taken to prevent pulpal damage. Although the esthetics of acrylic temporaries can be acceptable, their opaqueness looks less natural than the alternatives.
Given these disadvantages, products formulated with a self-curing bis-acryl composite resin have become the most widely used choice for provisionalization in recent years. Common brands include Luxatemp (DMG America, dmg-america.com), Integrity (Dentsply International, dentsply.com), ProtempTM Plus (3M ESPE, 3m.com), Venus® Temp 2 (Heraeus Kulzer, heraeus-kulzer-us.com), and Structur 2 SC (Voco America, voco.com). Bis-acryl temporaries differ from acrylics in that their viscosity cannot be changed. Because some are more brittle, careful consideration must be given to where they will be used in the mouth. Excellent esthetic results can be achieved; however, bis-acryl has none of the negative characteristics associated with acrylic. Although the material is more expensive than acrylic ($3 to $5 per restoration), a bis-acryl temporary can be fabricated in approximately half the time required to make an acrylic. Hence, the cost of the dental assistant’s time must be considered in comparing the use of these two materials.
Bis-acryl temporaries typically can function well for at least 1 or 2 months. If a longer-term solution is required, for example, because more healing is required for an implant, a milled temporary represents a third alternative, which has been available for more than a dozen years. With the utilization of a chairside CAD/CAM milling system such as CEREC or Planmeca, the clinician can now choose among a number of materials that can be expected to function well for many months (or longer, often being employed for permanent crowns).
The use of polymethyl methacrylate may offer a chairside milling option. The material costs are far more expensive than acrylic or bis-acryl choices. The requisite milling and polishing operations may require 15 minutes. For strength, durability, and excellent esthetics, a milled temporary restoration may be the appropriate choice for certain patients.
A Necessary Evil?
Temporary restorations have been described as a necessary evil. Some dental professionals worry that if the temporary restoration looks too good or lasts too long, the patient may delay returning for delivery of a definitive restoration. However, temporaries are important for many reasons. In addition to providing a more esthetic appearance while the implant heals or the definitive restoration is being fabricated, temporaries protect the healing implant site and prevent sensitivity. They protect the prepared tooth from the oral environment, including bacterial contamination and temperature changes. In the case of prepared teeth, the position in the arch of both adjacent and occluding teeth must be maintained or restored for biologic width. If the occlusion, interproximal contact, or the prepared tooth are allowed to move, the final prosthesis may not fit or seat accurately, requiring an inordinate amount of time for adjustment—or, in the worst case, a new impression and a remake.
Temporaries are necessary. However, careful attention to which kind of temporary suits each situation can enhance the overall cost efficiency of the practice.