Dental implants are a popular and effective way to replace missing teeth providing highly aesthetic results that mimic the natural tooth. It is an artificial material placed into the bone to support the cap or bridge. Dental implants are made of various materials like metal alloys (titanium), ceramics (Alumina, Hydroxyapatite).
Titanium and its alloys are considered to be the “gold standard” material for the fabrication of endosseous dental implants based on their long-term clinical survival rates. There are four grades of commercially pure titanium (CpTi) and two titanium (Ti) alloys. Commercially pure titanium is also referred to as unalloyed titanium and usually contains some trace elements of carbon, oxygen, nitrogen and iron. Theses trace elements improve the mechanical properties of pure titanium and are found in higher amounts from Grade I to Grade IV.
Types of dental implants
Dental implants are classified based on the location and design.
Design & Surface
Screw-type implants increase the surface area for osseointegration. Threads help in stabilization by improving bone to implant contact and in stress distribution. Cylindrical Implants are indicated when the bone is of good quality and has a uniform thickness used in single and multiple-tooth restorations. Tapered implants have a diameter that gradually decreases towards the apex or tip, intended to match the natural shape of tooth roots, often chosen when there is limited bone width, as they can be easier to insert into narrower spaces. Roughened smooth surfaces of the implants were altered to a textured surface to increase the surface area for osseointegration.
Length
- Extra-short: 6 mm in length or less.
- Short: From more than 6 mm to less than 10 mm.
- Standard: From 10 mm to less than 13 mm.
- Long: More than 13 mm.
Most commonly used dental implant design and structure:
Most commonly used and popular design is endosteal root form implants. They are screwed into the jaw bone surgically. Then an attachment is connected (abutment) over which the crown is placed.
Different types of implants are needed for different situations as mentioned below:
- Post extraction immediate implant placement
- Implants in anterior esthetic zone
- Atrophic maxilla, mandible
- Implants in growing patients
- Implants in medically compromised patients
An Implantologist with necessary experience and surgical skills can perform the implant surgery. The precise evaluation of distinct anatomical factors such as the position of the mandibular canal, maxillary sinus, the width of the cortical plates, the existing bone density, etc. is very important in appropriate implant selection and planning the most appropriate implant position in the existing clinical condition.
Dental implant therapy can be advocated
- When there is Single tooth or multiple teeth missing.
- Dissatisfied patient with the existing unstable conventional denture.
They are however, contra-indicated when there is acute illness, the magnitude of defect or anomaly, uncontrolled metabolic disease, bone or soft tissue pathology/infections.
The steps involved in dental implant surgery include patient’s current health status and medications and details of past medical history and medical treatments. Intra oral photographs are taken for documentation. Radiographic examination i.e. Cone Beam Computerized Tomography (CBCT) is done to determine the status and anatomy of the underlying bone for the implant placement and need for any other surgical procedures.
Implants adjacent to natural tooth are differentiated into comfort zone, which is the ideal position for an implant and danger zones where implants should not be placed. The ideal mesiodistal distance between a natural tooth and the shoulder of an implant is 1.5 mm. The zone up to 1–1.5 mm from the adjacent teeth on either side is the danger zone. Between the danger zone is the comfort zone that is safe for implant placement. The oral aspect has a danger zone as well, indicating that an implant should not be placed too far orally or too far facially.
Implants adjacent to each other: The distance between the implants should be at least 3 mm, this is critical to allow adequate inter implant bone and hence the formation of a soft tissue papilla overlies the bone.
The survival rate of implants is considered to be greater than 96%.
THE GOAL OF IMPLANT THERAPY:
The goal of modern implant dentistry is to restore the patient to normal profile, function, comfort, esthetics, speech, and health regardless of the atrophy, disease, or injury of the stomatognathic system.
Dental implants are increasingly used to replace single teeth, especially in the posterior regions of the mouth. Rather than removing sound tooth structure and crowning two or more teeth, increasing the risk of decay, endodontic therapy, and splinting teeth together with pontics, which may have the potential to decrease oral hygiene ability and increase plaque retention, a dental implant may replace the single tooth.
