Since the introduction of dental implants, research has demonstrated that the clinical effectiveness of implant-supported prostheses equals or surpasses the performance of conventional fixed or removable prosthetic therapy. The scientifically documented success of implants has led to the development of many different implant designs, materials, surface technologies, and surgical methods. Numerous companies manufacture and market implant systems, and most of these systems include implants of more than one design. At present there are well over 2,000 different implant designs available worldwide. Moreover, some of these systems include prosthetic components designed to be compatible only with implants from the same manufacturer. Therefore, choosing an implant system requires careful consideration. This Module will review the various factors that should influence the clinician's selection of the most appropriate system for their patients.

After completing this ITIAcademy Module, you should be able to: identify the scientific documentation needed to support selection of an implant system, describe the product characteristics that influence system selection, describe the manufacturer characteristics that influence system selection, and explain cost considerations when selecting an implant system.

An important aspect of selecting an implant system is the assessment of available documentation on that system. Some forms of documentation are more valid than others and should therefore carry more weight in the decision-making process. Advertisements, publications from manufacturers, and other marketing materials are one type of documentation; however, these are intended as product endorsements and are not scrutinized through the process of peer review. The information they present may be liable to misinterpretation. Another source of documentation is 'expert opinion', which is information presented by respected authorities in publications or at continuing education meetings. Although expert opinion may be derived from direct clinical experience, it may be true only relative to the experience of that clinician. Another clinician may or may not obtain the same results when implementing the techniques described by the expert. Therefore, expert opinion must not be confused with personal experience. However, both expert opinion and personal experience have potential for bias.

The best documentation of implant performance is outcome data from scientific investigation published in peer-reviewed scientific journals. The clinician may then read and interpret the information presented. It is important to note that, due to differences in the methods of scientific investigation, some published data are more valid than others. Validity is a measure of how accurately the results of scientific investigation reflect the truth. The greatest threat to the validity of a research study is bias. Some types of research studies are more susceptible to bias than others. More information on bias in research may be found in the Learning Module on 'Locating and Evaluating Relevant Scientific Literature'.

Published outcome data should document the survival and success of a system's implants as well as the prostheses they support. 'Survival' is defined as the implant being present in the patient's mouth at the time of examination, regardless of the presence of complications. The 10-year survival rate of well-documented implant systems is greater than 95%. Clinicians should select implant systems that are thoroughly researched and have properly documented survival data for implants supporting single-unit, multi-unit, and full-arch prostheses.

Implant success differs from implant survival. Implants are considered to be successful if they are present without complications and fulfill defined criteria over a period of observation. Accepted success criteria include lack of pain, paresthesia, inflammation, infection, mobility, and bone loss. The primary function of a dental implant is to support or retain the prosthesis, similar to the relationship between a natural tooth root and coronal tooth structure. Any success criteria, therefore, must include support of a prosthesis that provides the patient with function, comfort, and esthetic satisfaction, minus complications that compromise these outcomes.

For any implant system, biologic complications affecting the peri-implant tissues in the form of crestal bone loss or total loss of implant integration should be documented in the scientific literature. Such data allow the clinician to understand the likelihood of long-term survival and ongoing satisfactory clinical performance. Likewise, mechanical complications such as loosening of abutment or prosthetic screws, loss of retention, or fracture of the implant, abutment, prosthesis, or veneering materials should be identified through scientific investigation. Implants must support prostheses in a durable fashion; however, no dental prosthesis is expected to last forever. Because replacement of virtually any prosthesis will be required over time, it is beneficial to have information on the expected time to replacement of both the prosthesis itself as well as individual components such as abutment screws.

Dental implant systems should demonstrate general reliability for multiple clinical applications. Some implants, however, are designed for very specific applications. Some examples are narrow-diameter implants that are used for incisor replacement or orthodontic anchorage, wide-diameter implants used for molar replacement, short implants that are used to when bone augmentation may not be possible, or implants with thread patterns that establish greater primary stability when low-quality bone is encountered. The reliability of these implants for their specific applications should also be shown through scientific investigation.

Lastly, it is important to confirm that the manufacturer has obtained appropriate regulatory body approval for sale and distribution of the implant system. Most countries have regulatory bodies that are designed to monitor the safety and effectiveness of medical devices before such devices are marketed to the public. In the United States this body is the Food and Drug Administration, or FDA, whereas the regulatory bodies in the European Union rely on standards developed by the International Organization for Standardization, or ISO. These organizations and others throughout the world provide guidelines that allow medical devices such as dental implants to be sold in the marketplace. The regulatory bodies do not generally perform their own testing; instead, they evaluate previous testing to ensure the safety and effectiveness of devices that are allowed onto the market.

Scientific Documentation, Key Learning Points: The clinical performance of an implant system should be documented through scientific investigation. The documentation should differentiate between implant survival and success. Reports on the success rates of an implant system should include data on biologic and mechanical complications. Implant systems require regulatory approval for sale and distribution.

An ideal system should consist of a portfolio of implants and prosthetic components to address a broad range of clinical needs, from single-unit to full-arch rehabilitations. Often an implant system will consist of multiple implant types suited to address different clinical situations. A system that includes implants appropriate for bone of differing quality, for sites in both esthetic and non-esthetic zones, and for immediate, early, and late loading protocols will provide the clinician with maximum flexibility.

A minimum requirement is that a system consists of implants in a variety of lengths and diameters. As the implant macrostructure plays an important role in achieving primary stability at the time of placement, it is preferable that a system includes implants in both tapered and parallel body designs with a choice of thread configurations.

An ideal system will also include both one-piece and two-piece implants as each design exhibits specific clinical advantages and disadvantages. One-piece implants promote stable bone levels through a vertical offset of the implant-abutment interface whereas two-piece implants offer greater prosthodontic flexibility because the prosthodontic platform is part of a separate abutment. Two-piece implants with a horizontal offset are preferred over two-piece implants without an offset because they have been shown to be associated with less crestal bone loss. For both one and two-piece implants internal abutment connections are preferred to external connections because of better precision fit and stability. The variations listed on this slide are discussed in detail in the Learning Module 'Implant Designs and Characteristics'.

The available implants should have a surface that is conducive for rapid osseointegration and high bone-to-implant contact. These outcomes should be documented by in vivo studies. As a general recommendation, implants should have microsurface roughness of 1 to 2 microns, which is considered to be moderately rough. More information on implant design may be found in the ITI Academy Learning Module ‘Implant Designs and Characteristics'.

An important consideration for any implant system is its range of prosthetic components to address different clinical situations. Because the initial prosthodontic plan may change with the loss of additional teeth, a broad range of prosthetic components also allows a treatment plan to be more easily modified. Abutments in various heights and widths, both straight and angled, will provide maximum versatility to satisfy clinical needs. An implant system should also include options for the abutment material such as titanium, zirconia, and ceramic to address clinical situations or fulfil specific patient desires. Another consideration is the availability of digital workflows that incorporate CAD/CAM production of prosthetic components, such as patient-specific abutments, overdenture bars, and fixed dental prosthesis suprastructures.

The clinician should also evaluate the manner in which the implants and components are packaged. Dental implants must be sterile when they are inserted. After fabrication, implants should be packaged in a way that maintains the sterility that was achieved during the manufacturing process and that allows simple and safe transfer to the surgical environment. Typically, the primary packaging is a sterile inner vial containing the sterile implant; this is sealed inside a secondary blister package. In an aseptic surgical protocol the blister package is opened and the inner vial is dropped onto the surgical tray. Another consideration is the 'shelf life' of sterile implants. If sterility can be maintained for long periods of time, the extended shelf life of the implants reduces overhead expenditures related to replacing out-of-date inventory. Implant packaging should allow easy identification of different implants and components such as healing caps and abutments during clinical procedures. Packaging may be color-coded based on implant type or diameter, with corresponding colors used for prosthetic components such as abutments and impression copings. Easily identifiable packaging helps the clinician and staff to more easily maintain the inventory of implants and components. It is also helpful if implants are packaged with labels that facilitate the recording of product lot numbers and other relevant product information in patient records.

An implant system's surgical kit is an important consideration. Instruments used during implant placement should be contained in a cassette or tray. Necessary instruments include drills and placement tools such as alignment pins and torque wrenches. A well-designed surgical kit is arranged in a logical fashion that mirrors the surgical sequence, allowing the clinician to easily find and use instruments in the correct order. If the implant system includes more than one type of implant and the surgical kit is specific to a certain implant type, this should be clearly indicated on the cassette. Inside the cassette, color-coding of instrument workflows according to implant diameter will aid the clinician in operating efficiently. The surgical kit should provide for protection of instruments during the process of sterilization. A lid that closes securely will prevent the loss, disorganization, and damage of surgical instruments.

A prosthetic kit containing instruments needed for impression-taking procedures and delivery of implant prostheses is a key part of an implant system. Just as it is important for surgical instruments to be arranged in a logical fashion, it is likewise important for prosthetic components to be conveniently arranged in the order in which they are to be used. Color-coding of instruments can prevent damage caused by the use of inappropriately sized instruments. Similar to the surgical kit, security of the instruments within the tray setup is important during prosthetic procedures.

It is inevitable that clinicians will need to purchase new instruments over time. It is beneficial to receive instruments that are packaged securely to avoid injury to any of the clinical staff from contact with sharp unpackaged instruments. At the same time the packaging should allow the clinical staff to view the instruments to ensure that the correct instrument is being chosen. Although it is important for the packaging to be secure, the clinical staff should be able to open it easily without damaging the instrument.

Product Characteristics, Key Learning Points: An implant system should include a portfolio of surgical and prosthetic components to address a broad range of clinical needs. Sterile dental implants should be provided in clearly labeled packaging that allows aseptic transfer to the surgical tray. Easily identifiable packaging of implants and components will facilitate clinical procedures and inventory control. Surgical and prosthetic kits should be arranged so that the clinician can easily find and use the correct instruments.

Within the field of implant dentistry there are literally thousands of different dental implants that are being fabricated by hundreds of implant manufacturers. New implant companies enter the market every year. Clinicians cannot predict which new manufacturer will be successful, and which will fail in the marketplace. For this reason, caution is appropriate when considering the use of a new manufacturer, especially if the designs proposed by the manufacturer are not compatible with components already available in the marketplace. Smaller or newer companies may not be around years from now, but an implant that the clinician placed may well be. Therefore it is recommended to select an implant company with long-term patient outcomes in mind.

As implant companies evolve, so do the products they offer. Many implant manufacturers are involved in research and development, both to upgrade existing implants and components as well as to broaden their product portfolio by taking advantage of innovations in dental technology. Clinicians should consider implant systems from manufacturers with a commitment to ongoing clinical research and product development. On the other hand, some manufacturers will continually present claims of improved performance, ease-of-use, or cost effectiveness. If an implant system is constantly undergoing significant revision, components necessary to replace prostheses could be unavailable when needed. Although clinicians are not responsible for manufacturer changes in components, patients may become disenchanted with clinicians who chose implant systems with a poor record of consistency.

For clinicians, inventory control is a critical factor in the efficient management of the practice. When components are readily available and the manufacturer can fill orders in a few days, the need to maintain a large inventory is diminished, which may reduce the clinician's overhead expenses. Conversely, when products are out of stock, have been discontinued, or are available only through special orders, delays in treatment can have a negative impact on patient care and practice efficiency. Many implant systems integrate digital workflows and CAD/CAM production of patient-specific custom components in either the dental office or laboratory. Fabrication of CAD/CAM components in a timely manner further reduces the time and cost of inventory management.

Clinicians should also take into consideration the availability of manufacturer support when selecting an implant system. Many implant systems employ local sales representatives. These local representatives are often well versed in both the products that they represent as well as the products of competing companies. In addition to aiding the clinician with product orders, sales representatives may provide continuing education and in-person chairside training on surgical and prosthetic kits. A clinician new to implant dentistry may particularly benefit from this level of support. When a local representative is not available, a clinician will likely go to the manufacturer's website. An effective website will provide comprehensive product information, resources such as catalogs and manuals, and scientific documentation in an easy-to-navigate format. Some manufacturers offer online ordering. Although most implant system websites do not have the capability to provide the clinician with immediate feedback, some manufacturers provide online live chat support for discussing specific product concerns.

Manufacturer Characteristics, Key Learning Points: A manufacturer's reputation and longevity should be taken into account. The manufacturer should support clinicians through ongoing research and development as well as in-person and online product support. Practice efficiency is enhanced when the manufacturer has the ability to provide products when needed.

A clinician intending to practice implant dentistry must first invest in the major equipment associated with implant placement. Electrical equipment such as drill motors, handpieces, drilling unit consoles, and irrigation systems fall into the category of major equipment expenses. Of equal importance are the implant surgical kit and hand instruments such as retractors and elevators. In some implant systems, known as 'closed' systems, the drilling equipment for implant placement is exclusive to the system. The need to purchase specific placement equipment can result in increased expenditures by the dentist. Fortunately, most implant systems no longer embrace this approach. 'Open' systems, on the other hand, employ equipment and instruments that can be used with implants from different manufacturers. This is preferable to purchasing items that can be used with only one system. Moreover, open implant systems are often more favorably priced. The purchase of major equipment and most instruments is generally considered to be a one-time expenditure; however, these items may eventually need replacement due to wear and tear.

The cost of the implant itself is an important consideration. However, implant placement requires associated items that can have a significant effect on the total cost. For example, drills and taps used during surgery must be sharp to ensure efficient preparation of the osteotomy with minimal trauma to the bone. Implant systems may offer multi-use drills or single-use drills; some implant systems offer both. Multi-use drills require frequent replacement. Occasionally the clinician or assistant may remove an implant or component from its packaging, and yet that item is not ultimately inserted or used in the patient. Clinicians should be aware of manufacturer policies regarding packages that have been opened during surgery, as these policies can have a profound impact on total cost. A manufacturer may or may not allow implants or components to be returned for credit once they have been removed from their original packaging. Likewise, the clinician needs to have a clear understanding of a manufacturer's policy on implants that fail to achieve or maintain osseointegration. Some manufacturers will replace implants that have failed to integrate. An awareness of these policies will aid the clinician in creating their own financially viable policy towards replacement of failed implants and prostheses.

Costs associated with the prosthetic steps of implant treatment can be generally divided into provisional, impression, and prosthodontic components. On the day of surgery, the implant will requir a cover screw, healing abutment, or provisional prosthesis. There are different costs associated with each of these methods. Fabrication of the definitive prosthesis requires further components for the impression procedure as well as an abutment, either prefabricated or CAD/CAM fabricated. For many implant systems, the components needed for each of these steps can be obtained from a different company than the implant manufacturer. These 'non-original' components are often more favorably priced; however, the dentist should be aware of potential drawbacks to mixing and matching implants and components. Documentation of the long-term performance of non-original parts is not always readily available. They may also lack the high manufacturing precision of components from systems that are developed through traditional research, development and clinical testing. When non-original components are used, the implant-abutment connection may lack the integrity, accuracy of fit, and durability that can be achieved with components available from the implant manufacturer. Moreover, the use of non-original components may void the manufacturer's warranty on the implant itself.

Proper maintenance is essential to ensure the health of the peri-implant tissues and the longevity of the implant. The titanium and titanium alloys from which implants are fabricated are highly susceptible to scratches and surface alterations. Maintenance of dental implants requires the purchase of specialized non-metal ultrasonic scaler tips and manual instruments designed to debride the implant surface. The clinician must also purchase dedicated sharpening stones for non-metal instruments; stones that have been used with stainless steel instruments may contain specks of metal that could be transferred to the implant. Finally, air polishing technology can also be used to remove plaque from implant and prosthetic surfaces.

Finally, it is important for the dentist to weigh the costs of using a particular implant system, including implants, equipment, instruments, and associated items, against the services provided by the system's manufacturer. The research and development behind the products offered, the expertise of the sales representative, the availability of support and education, and the product warranties are just a few of the considerations. This is especially important for the clinician just starting out in implant dentistry.

Cost Considerations, Key Learning Points: The total costs associated with implant placement are affected by recurring costs associated with implant placement as well as manufacturer warranties and replacement policies. Non-original prosthetic components are often competitively priced, but there are potential disadvantages to their use. Services and support provided by a manufacturer add value to an implant system.

Selecting an Implant System, Module Summary: Any implant system under consideration should provide long-term clinical outcomes for their products, including survival and complication rates. A comprehensive portfolio of surgical and prosthetic components will aid the clinician in addressing a variety of clinical needs. The availability, packaging, and provision of implants and other items in a system can affect the efficiency of the dental practice. When selecting a system, the clinician should compare the implant and component prices against the services and policies provided by the manufacturer.