Dental Treatments
Implantology
A dental implant is a "root" device, usually made of titanium, used in dentistry to support restorations that resemble a tooth or group of teeth to replace missing teeth.
Virtually all dental implants placed today are root-form endosseous implants, i.e., they appear similar to an actual tooth root (and thus possess a "root-form") and are placed within the bone (endo- being the Greek prefix for "in" and osseous referring to "bone"). The bone of the jaw accepts and osseointegrates with the titanium post. Osseointegration refers to the fusion of the implant surface with the surrounding bone. Dental implants will fuse with bone; however, they lack the periodontal ligament, so they will feel slightly different from natural teeth during chewing.
Dental implants can be used to support a number of dental prostheses, including crowns, implant-supported bridges or dentures. [1] They can also be used as anchorage for orthodontic tooth movement. The use of dental implants permits undirectional tooth movement without reciprocal action.
Dental implantology is a set of surgical techniques aiming at the functional rehabilitation of a patient affected by total or partial edentulism, by using dental implants, i.e. metal elements surgically inserted in the mandibular or maxillary bone, or above them but under the gum. These elements are fitted with connectors to fasten them to fixed or removable prostheses, to enable chewing functionality. Such implants can have different shapes, they can be inserted in different positions, with different techniques, then connected to prostheses at different times.
SURGICAL PROCEDURE
- Surgical planning
A prior to commencement of surgery, careful and detailed planning is required to identify vital structures such as the inferior alveolar nerve or the sinus, as well as the shape and dimensions of the bone to properly orient the implants for the most predictable outcome. Two-dimensional radiographs, such as orthopantomographs or periapicals are often taken prior to the surgery. Sometimes, a CT scan will also be obtained.
- Basic Procedure
In its most basic form, the placement of an implant requires a preparation into the bone using either hand osteotomes or precision drills with highly regulated speed [24] to prevent burning or pressure necrosis of the bone. After a variable amount of time to allow the bone to grow on to the surface of the implant (osseointegration), a crown or crowns can be placed on the implant. Unlike conventional dental implants, Mini dental implants may be loaded immediately and still have a high survival rate (94%). [25][26] The amount of time required to place an implant will vary depending on the experience of the practitioner, the quality and quantity of the bone and the difficulty of the individual situation.
- Detail Procedure
At edentulous (without teeth) jaw sites, a pilot hole is bored into the recipient bone, taking care to avoid the vital structures (in particular the inferior alveolar nerve or IAN and the mental foramen within the mandible). Drilling into jawbone usually occurs in several separate steps. The pilot hole is expanded by using progressively wider drills (typically between three and seven successive drilling steps, depending on implant width and length). Care is taken not to damage the osteoblast or bone cells by overheating. A cooling saline or water spray keeps the temperature of the bone to below 47 degrees Celsius (approximately 117 degrees Fahrenheit). The implant screw can be self-tapping, and is screwed into place at a precise torque so as not to overload the surrounding bone (overloaded bone can die, a condition called osteonecrosis, which may lead to failure of the implant to fully integrate or bond with the jawbone). Typically in most implant systems, the osteotomy or drilled hole is about 1mm deeper than the implant being placed, due to the shape of the drill tip. Surgeons must take the added length into consideration when drilling in the vicinity of vital structures.
- Healing Time
The amount of time required for an implant to become osseointegrated is a hotly debated topic. [29] Consequently the amount of time that practitioners allow the implant to heal before placing a restoration on it varies widely. In general, practitioners allow 2–6 months for healing but preliminary studies show that early loading of implant may not increase early or long term complications. [30] Minimally invasive methods of early dental implant placement reduce the cost of installed implants and shorten the implant-prosthetic rehabilitation time to within 4–6 months. [31] If the implant is loaded too soon, it is possible that the implant may move which results in failure. For conventional implants, the subsequent time to heal, possibly graft, and eventually place a new implant may take up to eighteen months. For this reason many are reluctant to push the envelope for healing.
- Surgical Timing
There are different approaches to place dental implants after tooth extraction. The approaches are:
- Immediate post-extraction implant placement.
- Delayed immediate post-extraction implant placement (2 weeks to 3 months after extraction).
- Late implantation (3 months or more after tooth extraction).
According to the timing of loading of dental implants, the procedure of loading could be classified into:
- Immediate loading procedure.
- Early loading (1 week to 12 weeks).
- Delayed loading (over 3 months)
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