Different Dental Implant Systems
As the population ages and technology improves, dental implant treatment continues to increase in popularity. Dental implants allow their wearers to enjoy a variety of foods, smile with confidence, and speak comfort and ease. As the implant market expands, dental technology continues to advance, providing options for innovative techniques and materials that improve the treatment process and the fit, reliability, and appearance of the restorations. Dental health professionals need to be aware of the multitude of possibilities available to their patients so that they can choose the most appropriate options for each patient.
Currently, there are more than 100 companies that make the components for dental implants. The most respected of these companies are Straumann, Zimmer Biomet, Nobel BioCare, MIS, BioHorizon, and Dentsply. While the lesser-known companies and generic options may be less expensive than these well-known brands, many patients prefer to choose a known product with a history of documented success. Many of these larger companies have invested significant time and money into research and development of their products, guaranteeing biocompatibility and durability. These better-known companies may also be preferable because of their familiarity within the dental community; for example, dentists and dental laboratory technicians are likely to be more familiar with the specifications of these better-known products, making them easier to use and providing better outcomes. It is also easier to replace component parts, when needed, when the components are consistent and widely available.
Another choice that must be addressed when planning for dental implants is the decision between cement-retained abutments and screw-retained implants, and the decision between custom abutments and stock abutments. Custom abutments are generally preferable for aesthetic reasons, though this varies depending on the situation. Dentists must also consider whether they plan to use titanium or zirconium for implant fixtures, and what material they may prefer to use for the crowns.
To inform the decision between cement-retained crowns and screw-retained crowns, dentists must think about retrievability, possible effects on the gingival tissues, ease of use, appropriateness for the specific case, and cost. If it is necessary to remove a crown for any reason, it is often easier to remove crowns that are screw-retained. Dental cement may also damage the tissues of the gum, if there is excessive cement that seeps into the gingival sulcus. This can increase the risk of inflammation following the placement of an implant. While dentists are adept at removing excess cement after placing a crown, there is always the chance that some cement can be missed and remain below the gums. This is not a risk when using screw-retained implant crowns. It may be more challenging to place a screw-retained crown than a cement-retained crown, however, especially when multiple restorations are needed. It may also not be possible to use screw-retained crowns when the dental implants are angled in the jaw, which may be necessary when there is a lack of available bone to place perpendicular implants.
Stock abutments are available in standard sizes and are considered a user-friendly option. Most stock abutments are used for cement-retained restorations and are considered a cost-effective choice. Because stock abutments are standard-sized, however, they are not recommended for the front teeth, as a portion of the abutment may be visible above the gumline and it is more difficult to create an attractive yet strong and functional crown. Stock abutments may also necessitate a larger investment in shaping and modifying for fit and appearance following the placement of the implant and the crown. Custom abutments, on the other hand, can be shaped precisely to match the gumline and are therefore preferable for visible teeth, for aesthetic reasons. Custom abutments may be made from titanium, zirconium, or a combination of both materials. Custom abutments are more expensive than stock abutments, though they require less time to place and are more predictable, both in terms of tissue health and appearance. They also require less time, and therefore less cost, for modification and clinical maintenance after being placed. Custom abutments can be used for screw-retained or cement-retained crowns.
Titanium-alloy implant fixtures have proven biocompatibility and durability, with a success rate of 95% or more. These alloys are stronger than pure titanium, but they may include metals that are more allergenic than titanium, like nickel. When people have a sensitivity to nickel, or if they are hesitant to have metal placed into their bodies, zirconium may be preferable. Zirconium, a ceramic, contains only trace amounts of metals, is strong and durable, and is as biocompatible as titanium. Because zirconium has only been used for dental implants for a relatively brief period, however, there is insufficient data to determine long-term success rates with zirconium implants. Titanium alloys also allow greater versatility, as they may be fabricated as either one-piece or two-piece systems, which allow them to be used for a wider variety of restoration types; zirconium implants are only fabricated as one-piece systems.
Crowns that are compatible with custom abutments may be made from any number of materials, including porcelain fused to metal, a ceramic material known as eMax, gold, and zirconium. Gold and porcelain fused to metal are versatile and sturdy, and both can be good options when there is limited space available for restorations. However, both can cause complications when aesthetics are important, as with the front teeth. Zirconium and eMax provide better aesthetic results, though there is less data to prove their long-term efficacy. Ultimately, the choice of material that is used for dental crowns will depend on the type and location of the abutment, and the preferences of the patient.
As innovations in implant dentistry evolve, digital imaging technology is allowing dentists to use intraoral scanners to create models for dental restorations, eliminating the challenges that may have arisen from the use of dental impressions. Dental impressions require considerable skill and experience, and, even when they are fabricated by highly skilled dentists, limitations of the materials used when making dental impressions can lead to issues with the fit of the crafted restoration. Digital impression files provide highly detailed models that allow precision restorations to be manufactured more consistently and with greater reliability. Digital impressions may be used to build models that are used as the basis for conventionally made laboratory restorations, or they may be used to design restorations directly with computer-aided design and manufacturing software. These advances in design allow clinicians and technicians to create precisely fitted and dependable crowns from a full array of materials. While these digital technologies can provide savings in lab and materials costs, investment in the digital technologies, and in training clinicians to use them, is likely to increase the cost and offset any other savings. Digital scans can be preferable for patients, as they tend to be more comfortable than making manual impressions, and they provide the greatest degree of accuracy. They can also be manufactured more quickly than restorations made from conventional models, and they are less likely to need significant modification when being fitted, shortening the overall time of treatment.
Some dental practices have adopted cone beam CT technologies to use scans that can support multiple procedures, including the diagnosis and placement of dental implants and the procedures associated with implant surgery. Cone beam CT technology exposes the patient, and the clinicians, to considerably less radiation than conventional CT scans and allows the clinicians to see the most accurate rendering of the patient’s maxillofacial skeleton. This provides comprehensive data that can be used to precisely assess the amount of available bone, to detect any pathologies that may interfere with surgery, and even to generate 3D models of what completed restorations may look like. Cone beam CT technology can also reduce the completion time for restorations and increase the likelihood of implant success, and it can be used to create a surgical guide that provides greater precision during implant surgery, especially surgeries with complex placements or other potential challenges. Surgically guided implants can facilitate surgical treatments that require fewer incisions and therefore take less time both to perform, and to heal.
Choosing the best type of implants and the optimal material for restorations can be clinically challenging. The anatomy of the patient, including the volume of bone and the precise location of nerves, must be thoroughly understood in order for restorations to be successful. Advances in technology and planning have led to the creation of the full-arch zirconium implant-retained bridge as an optimal restoration choice for many patients. Zirconium is strong and versatile and can produce full arches that are extremely resistant to fracturing and chipping. It can also be crafted to create extremely realistic-looking arches, including the gum tissue, and it allows full arches to be placed where there is limited vertical space. Zirconium arches can be retained with either screws or cement, depending on specific clinical needs, and digital technologies help create zirconium restorations that are precisely fitted.
Thanks to innovations in dental technology, dental implants continue to improve and the options available continue to increase. While the broad selection of implant options may be confusing at first, your dental health professional can better explain the options that may be suitable for your clinical and aesthetic needs and for your budget. Whether you need to replace only a few teeth or a full arch, there is likely an implant type that will help you satisfy your dental restoration needs and contribute to an improved quality of life, so talk to your dentist about dental implant options that may work for you.