alloy and are designed to replace the root of one or more teeth. They are classified as blade‐ or root‐form, cylindrical/press‐fit or screw‐threaded, and come in many different sizes, lengths, and shapes. The blade‐form endosteal implant (Figure 1.13) is wide, flat metal plate or blade in cross section available in different heights and lengths, some with tapered sides. They may replace one to multiple teeth with a single blade and were used for narrow bones in maxillary or mandible, which had sufficient height to accommodate the implant placed. The blade‐shaped implants (see Figure 1.13) were surgically placed into the bone, then posts were attached to the blade, and an individual crown or bridgework affixed on the posts after a healing period.
Figure 1.11 Subperiosteal implant. Reprinted from Taylor and Laney (23), with permission from the author.
Figure 1.12 Transosteal implant.
Reprinted from Taylor and Laney (23), with permission from the author.
The root‐form implants (Figure 1.14) mimic the shape of natural root, threaded, smooth, or rough surface, with or without coating. They are stepped, parallel, or tapered, with or without grooves or vents and designed to join with multiple components to retain prosthesis. They can replace one to multiple teeth, are placed directly into the bone, and can be used in maxillary or mandibular arches. The bone must be of sufficient height, width, and length to accommodate the implant(s) placed. These implants are referred to as cylinder or press‐fit implants; screw‐retained implants also referred to as threaded implants or a combination of the two.
They are available in different widths, varying from 3.2 to 7 mm, and are available in different lengths, varying from 10 to 18 mm. The width and length are decided by the dentist, depending on the width and the height of the bone, the type of bone, and the number of teeth to be replaced. An implant‐supported abutment, often called a post, attaches to the surgically placed implant. Alternatively, one‐piece root‐form implants are also available that do not require placement of separate abutments. The two‐stage root‐form implants are placed in the bone, an abutment is attached to the implant, and the prosthesis is then placed. The final restoration or prosthesis is fabricated into a crown, bridge, or overdenture.
Figure 1.13 Blade‐form implants.
Courtesy of Dr. Frank Wingrove.
Figure 1.14 Endosteal root‐form implants.
Reprinted from Taylor and Laney (23), with permission from the author.
Looking to the future, we may see more endosteal implants made from ceramic (zirconia) or a combination of titanium and zirconia. Studies are being conducted due to its biocompatibility, tooth‐like color, mechanical properties, and low plaque affinity. It has the potential to become the alternative to titanium as the alloy of choice. More long‐term studies are being conducted on different rough surfaces with one‐piece ceramic (zirconia) dental implants, which to date, have an average of 95% success rate after 5 years (13). More specialized types of endosteal implants, to be aware of, are mini dental implants (MDIs) and zygoma implants.
Figure 1.15 Mini dental implants.
Courtesy of Glidewell.
MDIs (Figure 1.15) were introduced in the 1980s and accepted by the FDA as long‐term implant devices by 1999. They are very narrow (1.8–2.9 mm), some as thin as toothpicks, and can be temporary anchoring devices (TAD) or permanent MDIs used to stabilize a lower overdenture. They are solid, not hollow like traditional implants, and are made in one piece that includes the abutment. In most cases, mini implants are used in the lower jaw to stabilize a lower denture. They can also be used for temporary implants, replacement of smaller diameter teeth such as lower incisors, or in cases where a traditional implant is too large in diameter. They are generally placed as a single‐stage surgical process and are often loaded immediately.
Orthodontic implants/temporary anchoring devices (TADs)
TADs are titanium mini‐screws, used primarily by orthodontists. They are screwed directly into the bone through the gingiva to facilitate tooth movement and to anchor an orthodontic appliance. Once treatment is complete, the clinician can remove the TAD without trauma or need for bone grafting.
TADs are placed in adolescents to adults and used on an average of 6–12 months. Primarily used for stabilization and to assist in tooth movement without stressing the surrounding teeth. Also, used to force eruption of impacted canines or misaligned teeth, or to stabilize an appliance (14).
Hygienist’s role is to identify TAD patients, monitor, and treat to eliminate the biofilm and prevent soft tissue inflammation. Be aware, TAD implants may be located in the sulcus or palate of the orthodontic patients. Give patients the tools (i.e., sulcus or end tuft brushes), antimicrobial rinse, and other recommendations to eliminate the oral biofilm. Biofilm will accumulate on these TADs and can prevent the success of the orthodontic treatment as well as the overall oral hygiene of the patient. TADs are a tool in the toolbox for orthodontist to enable teeth to be moved in especially noncompliant patients with good oral hygiene as the KEY, see Chapter 8 for more recommendations on at‐home‐care.
Zygoma implants (Figure 1.16), also referred to as zygomatic implants, are longer than regular implants, initially developed by Brånemark in the 1980s. They are usually recommended to stabilize fixed full‐arch final prosthesis in maxillary jaw, in cases where severe bone resorption is present in the maxilla. They are longer than regular dental implants; they extend up to 55 mm, compared with 10–15 mm. Zygomatic implants penetrate through the maxillary sinus and anchor in the very dense zygomatic bone. The head of the fixture normally emerges in a slightly palatal position in the second premolar/first molar area of the maxilla. The advantage to this choice of treatment is for patients with insufficient bone quality who may not be good candidates for traditional implant treatment or traditional dentures because of the high level of bone resorption. This can allow these patients durable, long‐lasting, stable implant‐supported fixed final prosthesis without additional bone grafting procedures.
There are many styles and types of dental implants that have been placed and are currently being placed on the market today. Their use is determined by the type of bone available and the prosthesis needed to accomplish the treatment. Implant systems have been developed by different manufactures with a variety of component parts, but there are primary components