A dental implant (also known as an Endogenous implant or fixture) is a component that is placed in the bone of the upper jaw or lower jaw to support a dental prosthesis such as a crown, bridge. Dental implant is also used to support denture. The basis for modern dental implants is a biologic process called integration of dental implant material, titanium, to form a bond with the bone. The implant fixture is first placed in the bone to support the dental crown which looks very close to a natural tooth.
Success of Dental implant depends on surgical and restorative skills of dental Implantologist performing dental implant. Planning the dental implant is key to the long-term health of the dental implant with crown since bio mechanical forces created during chewing can be significant. We at dental Aesthetics use latest technology in planning Dental Implant with CBCT & CAD/CAM simulations for best dental implant Procedure. Our patient can eat and smile confidently with the help of dental Implant done at Dental Aesthetics.
A successful Dental Implant should last for life. The serviceability of dental implant is very important in long term success of dental Implant.
Soft tissue reflection
An incision is made over the crest of bone, splitting the thicker attached gingiva roughly in half so that the final implant will have a thick band of tissue around it. The edges of tissue, each referred to as a flap are pushed back to expose the bone. Flapless surgery is an alternate technique, where a small punch of tissue (the diameter of the implant) is removed for implant placement rather than raising flaps.
Drilling at high speed
After reflecting the soft tissue, and using a surgical guide or stent as necessary, pilot holes are placed with precision drills at highly regulated speed to prevent burning or pressure necrosis of the bone.
Drilling at low speed
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 low.
Placement of the implant
The implant screw is placed and can be self-tapping, otherwise the prepared site is tapped with an implant analog. It is then screwed into place with a torque controlled wrench 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).
The gingiva is adapted around the entire implant to provide a thick band of healthy tissue around the healing abutment. In contrast, an implant can be “buried”, where the top of the implant is sealed with a cover screw and the tissue is closed to completely cover it. A second procedure would then be required to uncover the implant at a later date.
There are different approaches to placement dental implants after tooth extraction. The approaches are:
- Immediate post-extraction implant placement is mostly done to provide replacement on missing tooth immediately.
- Delayed immediate post-extraction implant placement the crown is placed after a month to three months as it needs time to heal in the interest of the long term success.
- Late or Socket preservation. The implant is delayed due to severe loss of bone and soft tissue. The area of implant is preserved with bone and soft tissue augmentation. The dental implant is carried out after 3 to 6 months.
For an implant to become permanently stable, the body must grow bone to the surface of the implant (osseointegration). Based on this biologic process, it was thought that loading an implant during the osseointegration period would result in movement that would prevent osseointegration, and thus increase implant failure rates. As a result, three to six months of integrating time (depending on various factors) was allowed before placing the teeth on implants (restoring them).
However, later research suggests that the initial stability of the implant in bone is a more important determinant of success of implant integration, rather than a certain period of healing time. As a result, the time allowed to heal is typically based on the density of bone the implant is placed in and the number of implants splinted together, rather than a uniform amount of time. When implants can withstand high torque (35 Ncm) and are splinted to other implants, there are no meaningful differences in long-term implant survival or bone loss between implants loaded immediately, at three months, or at six months. The corollary is that single implants, even in solid bone, require a period of no-load to minimize the risk of initial failure.
One-stage, two-stage surgery
After an implant is placed, the internal components are covered with either a healing abutment, or a cover screw. A healing abutment passes through the mucosa, and the surrounding mucosa is adapted around it. A cover screw is flush with the surface of the dental implant, and is designed to be completely covered by mucosa. After an integration period, a second surgery is required to reflect the mucosa and place a healing abutment.
In the early stages of implant development (1970−1990), implant systems used a two-stage approach, believing that it improved the odds of initial implant survival. Subsequent research suggests that no difference in implant survival existed between one-stage and two-stage surgeries, and the choice of whether or not to “bury” the implant in the first stage of surgery became a concern of soft tissue (gingiva) management. When tissue is deficient or mutilated by the loss of teeth, implants are placed and allowed to osseointegrate, then the gingiva is surgically moved around the healing abutments.
An increasingly common strategy to preserve bone and reduce treatment times includes the placement of a dental implant into a recent extraction site. On the one hand, it shortens treatment time and can improve esthetics because the soft tissue envelope is preserved. On the other hand, implants may have a slightly higher rate of initial failure. Conclusions on this topic are difficult to draw, however, because few studies have compared immediate and delayed implants in a scientifically rigorous manner.
Hard tissue (bone) reconstruction
Bone grafting is necessary when there is a lack of bone. While there are always new implant types, such as short implants, and techniques to allow compromise, a general treatment goal is to have a minimum of 10 mm in bone height, and 6 mm in width. Alternatively, bone defects are graded from A to D (A=10+ mm of bone, B=7–9 mm, C=4–6 mm and D=0–3 mm) where an implant’s likelihood of osseointegrating is related to the grade of bone.
To achieve an adequate width and height of bone, various bone grafting techniques have been developed. The most frequently used is called guided bone graft augmentation where a defect is filled with either natural (harvested or autograft) bone or allograft (donor bone or synthetic bone substitute), covered with a semi-permeable membrane and allowed to heal. During the healing phase, natural bone replaces the graft forming a new bony base for the implant.
Three common procedures are:
1.The sinus lift
2.Lateral alveolar augmentation
3.Vertical alveolar augmentation.
Other, more invasive procedures, also exist for larger bone defects including mobilization of the inferior alveolar nerve to allow placement of a fixture, onlay bone grafting using the iliac crest or another large source of bone and microvascular bone graft where the blood supply to the bone is transplanted with the source bone and reconnected to the local blood supply. The final decision about which bone grafting technique that is best is based on an assessment of the degree of vertical and horizontal bone loss that exists, each of which is classified into mild (2–3 mm loss), moderate (4–6 mm loss) or severe (greater than 6 mm loss).