DENTAL IMPLANTS

A dental implant is an artificial tooth root replacement and is used in prosthetic dentistry to support restorations that resemble a tooth or group of teeth. There are several types of dental implants. The major classifications are divided into osseointegrated implant and the fibrointegrated implant.

DENTAL IMPLANTS What are Dental Implants? The dental implants are small posts made of titanium or titanium alloy which are inserted into the jawbone to replace the missing teeth. These metal anchors act as tooth root substitutes. They are surgically placed into the jawbone, where the implant becomes directly attached to vital bone, creating a strong foundation for artificial teeth. Small posts are then attached to the implant which protrude through the gums. These posts provide stable anchors for artificial replacement teeth. Dental implants are highly successful and help in preserving facial structure, and preventing the bone loss that occurs when teeth are missing. They give the person who lost natural teeth the ability to chew again with confidence. Anatomy of a Dental Implant A dental implant designed to replace a single tooth is composed of three parts: the titanium implant that fuses with the jawbone; the abutment, which fits over the portion of the implant that protrudes from the gum line; and the crown, which is created by a prosthodontist or restorative dentist and fitted onto the abutment for a natural appearance. Did you know that dental implants are frequently the best treatment option for replacing missing teeth? Rather than resting on the gum line like removable dentures, or using adjacent teeth as anchors like fixed bridges, dental implants are long-term replacements that your oral and maxillofacial surgeon surgically places in the jawbone. Statistics show that 69% of adults ages 35 to 44 have lost at least one permanent tooth to an accident, gum disease, a failed root canal or tooth decay. Furthermore, by age 74, 26% of adults have lost all of their permanent teeth.

Many people who are missing a single tooth opt for a fixed bridge; but a bridge may require the cutting down of healthy, adjacent teeth that may or may not need to be restored in the future. Then there is the additional cost of possibly having to replace the bridge once, twice or more over the course of a lifetime. Similarly, a removable partial denture may contribute to the loss of adjacent teeth. Studies show that within five to seven years there is a failure rate of up to 30% in teeth located next to a fixed bridge or removable partial denture.

Dental implants are designed to provide a foundation for replacement teeth that look, feel, and function like natural teeth. The person who has lost teeth regains the ability to eat virtually anything and can smile with confidence, knowing that teeth appear natural and that facial contours will be preserved. The implants themselves are tiny titanium posts that are placed into the jawbone where teeth are missing. The bone bonds with the titanium, creating a strong foundation for artificial teeth. In addition, implants can help preserve facial structure, preventing the bone deterioration that occurs when teeth are missing.  Dental implants are changing the way people live!  With them, people are rediscovering the comfort and confidence to eat, speak, laugh and enjoy life.

How Dental Implants Work- Dental implants are metal anchors, which act as tooth root substitutes. They are surgically placed into the jawbone. Small posts are then attached to the implant, which protrude through the gums. These posts provide stable anchors for artificial replacement teeth.

For most patients, the placement of dental implants involves two surgical procedures. First, implants are placed within your jawbone. For the first three to six months following surgery, the implants are beneath the surface of the gums gradually bonding with the jawbone. You should be able to wear temporary dentures and eat a soft diet during this time. At the same time, your restorative dentist designs the final bridgework or denture, which will ultimately improve both function and aesthetics.

After the implant has bonded to the jawbone, the second phase begins. Your implant surgeon will uncover the implants and attach a small healing collar. Then your doctor will be able to begin making your new teeth. An impression must be taken. Then posts or attachments can be connected to the implants. The teeth replacements are then made over the posts or attachments. The entire procedure usually takes six to eight months. Most patients do not experience any disruption in their daily life.

There are various different implants on the market and each one has its advantages. Please find listed below some that we use:

New NobelActive™ - from Nobel Biocare implants is a 3rd generation implant design. A breakthrough implant design with revolutionary bone-condensing capability. NobelActive™ offers unique advantages and is clinically documented 98% success rate * potentially fewer drilling protocol steps, depending on bone density and quantity. * Minimal osteotomy with minor trauma to bone and surrounding tissues * extremely high stability in fresh extraction sites and sites with thin sinus floors * ability to change direction during surgery gives full flexibility for optimal placement * a narrow neck designed to preserve marginal bone * grooves on threads and scientifically proven TiUnite™ surface
Straumann product Reliable. Simple. Versatile. With more than 20 years of clinical research that have resulted in over 3,000 independent scientific publications, we offer the most extensively documented, clinically validated and practice-proven implant system in the market.ads and scientifically proven TiUnite™ surface Reliable * Implants designed for optimal tissue response * Reduced healing time * Morse taper connection for maximum stability Simple * A logical component structure * Procedures that are easy to learn * One surgical kit Versatile * Successful outcomes with any indication * Free choice of surgical procedure * A wide range of prosthetic options
BIOMENT 3i The Revolutionary NanoTite™ Implant – A Bone Bonding™ Surface. Preclinical Studies Demonstrate A Substantial Improvement On The Rate And Extent Of Osseointegration For The NanoTite Implant Versus The OSSEOTITE Implant Leading To Implant Stability 12 Synergy Of The OSSEOTITE® Surface And Discrete Crystalline Deposition Of Calcium Phosphate (CaP) – More Complex Topography And The Biologic Benefits Of Cap
Branemark The Revolutionary NanoTite™ Implant – A Bone Bonding™ Surface. Branemark adheres to the principles of Osseointegration, a term founded by Professor Per-Ingvar Brånemark after his important breakthrough in the 1950s when he discovered that bone can integrate with titanium components. Professor Brånemark named his discovery from the Latin word os – which means bone, and integrate – which means make whole, which can also be expressed as interactive coexistence. We have developed bone grafting techniques that allow us to build bone where the original quantity is insufficient for fixture placement. But as grafting is a rather invasive procedure, we have also developed a technique for placing fixtures in the zygomatic cheek bone, which in many cases eliminates the need for grafting also in the severely resorbed maxilla. Another exciting development involves a procedure we call Brånemark Novum®. It eliminates the discomfort that can occur during a long healing period and the problems associated with a removable denture. Instead the fixtures are inserted in the morning and the final prosthesis is anchored in the afternoon. The patient can eat lighter food already at the end of the first treatment day. In addition, the new procedure costs significantly less than what is customary for restoring a completely edentulous mandible.
Impladent The Revolutionary Features of Bone Compaction by LaminOss® Taps - Bone compaction and minimal bone loss are achieved by the unique compound angles of the surgical taps that provide a simultaneous, progressive internal cutting edge, followed by the outer flat compressive surface area of the tap at the time of bone threading procedures. Impladent Ltd.develops, manufactures, and distributes a broad range of innovative synthetic bioactive resorbable bone products, osteocompressive immediate-load dental implants, chairside prosthetic modalities for immediate implant splinting and reconstruction, and a line of surgical motors and hand pieces. For over 17 years, Impladent Ltd. has been recognized as a leader in the innovation and development of synthetic resorbable bone grafts, osteocompressive immediate-load dental implants.

History of Dental Implants

The Mayan civilization has been shown to have used the earliest known examples of endosseous implants (implants embedded into bone), dating back over 1,350 years before Per Brånemark started working with titanium. While excavating Mayan burial sites in Honduras in 1931, archaeologists found a fragment of mandible of Mayan origin, dating from about 600 AD. This mandible, which is considered to be that of a woman in her twenties, had three tooth-shaped pieces of shell placed into the sockets of three missing lower incisor teeth. For forty years the archaeological world considered that these shells were placed under the nose in a manner also observed in the ancient Egyptians. However, in 1970 a Brazilian dental academic, Professor Amadeo Bobbio studied the mandibular specimen and took a series of radiographs. He noted compact bone formation around two of the implants which led him to conclude that the implants were placed during life.

In the 1950s research was being conducted at Cambridge University in England to study blood flow in vivo. These workers devised a method of constructing a chamber of titanium which was then embedded into the soft tissue of the ears of rabbits. In 1952 the Swedish orthopaedic surgeon, P I Brånemark, was interested in studying bone healing and regeneration, and adopted the Cambridge designed ‘rabbit ear chamber’ for use in the rabbit femur. Following several months of study he attempted to retrieve these expensive chambers from the rabbits and found that he was unable to remove them. Per Brånemark observed that bone had grown into such close proximity with the titanium that it effectively adhered to the metal. Brånemark carried out many further studies into this phenomenon, using both animal and human subjects, which all confirmed this unique property of titanium.

Although he had originally considered that the first work should centre on knee and hip surgery, Brånemark finally decided that the mouth was more accessible for continued clinical observations and the high rate of edentulism in the general population offered more subjects for widespread study. He termed the clinically observed adherence of bone with titanium as ‘osseointegration’. In 1965 Brånemark, who was by then the Professor of Anatomy at Gothenburg University in Sweden, placed the first titanium dental implant into a human volunteer, a Swede named Gösta Larsson.

Over the next fourteen years Brånemark published many studies on the use of titanium in dental implantology until in 1978 he entered into a commercial partnership with the Swedish defense company, Bofors AB for the development and marketing of his dental implants. With Bofors (later to become Nobel Industries) as the parent company, Nobelpharma AB (later to be renamed Nobel Biocare) was founded in 1981 to focus on dental implantology. To the present day over 7 million Brånemark System implants have now been placed and hundreds of other companies produce dental implants. All dental implants currently available are axilly symmetric (cylindrical form) and do not fit precisely in the individual tooth socket. For this reason additional risky and costly interventions are regularly required to fill the gaps between the implant and bone.

The latest development in immediate dental implantology are root analogue Zirconia implants, which fit exactly into the extraction socket, rendering additional procedures such as bone transplantation or implantation of bone substitute as well as drilling absolutely unnecessary.

Dental Implant Procedure

A typical implant consists of a titanium screw (resembling a tooth root) with a roughened or smooth surface. The very first implants were made out of commercially pure titanium, however since it was discovered that the TiAl6V4 alloy offered the same osseointegration level as commercially pure titanium, more and more implants were made out of TiAl6V4 alloy due to its better tensile strength and thus fracture resistance. Today most implants are made out of the TiAl6V4 alloy and treated either by plasma spraying, etching or sandblasting to increase the surface area and, thus the integration potential of the implant. An osteotomy or precision hole is carefully drilled into jawbone and the implant is installed in the osteotomy.

Implant surgery is typically performed as an outpatient under general anesthesia or with local anesthesia by trained and certified clinicians including general dentists, oral surgeons, and periodontists. An increasing number of general or cosmetic dentists as well as prosthodontists are also placing implants in relatively simple cases. The most common treatment plan calls for several surgeries over a period of months, especially if bone augmentation (bone grafting) is needed to support implant placements. At the other end of the surgery scale, some patients can be implanted and restored in a single surgery, in a procedure labeled "immediate function" and "teeth in an hour."

A single implant procedure that involves an incision and "flapping" of the gum or gingiva (to expose the jawbone) takes about an hour, sometimes longer; multiple implants can be installed in a single surgical session lasting several hours. At the conclusion, the patient goes through a period of recovery, returns to consciousness and is sent home with a relative or friend.

Healing and integration of the implant(s) with jawbone occurs over several months in a process called osseointegration. At the appropriate time, the restorative or cosmetic dentist or prosthodontist uses the implant(s) to anchor crowns or a prosthetic restoration containing several "teeth". Since the implants supporting the restoration are integrated, which means they are biomechanically stable and strong, the patient is immediately able to masticate (chew) normally.

In an immediate function procedure, the gingiva is not flapped (Flapless). Instead, the surgeon removes a small plug of gingiva directly over the drilling site. The site is drilled and the implant is installed. Then a crown is immediately added. Patients are cautioned to give their new "teeth in an hour" ample healing/integration time (weeks or months) before attempting normal mastication.

There are different approaches to place dental implants after tooth extraction. The approaches are:
1. Immediate post-extraction implant placement.
2. Delayed immediate post-extraction implant placement (2 weeks to 3 months after extraction).
3. Late implantation (3 months after tooth extraction).

According to the timing of loading of dental implants, the procedure of loading could be classified into:
1. Immediate loading procedure.
2. Early loading (1 week to 12 weeks).
3. Staged loading (3-6 months).
4. Late loading (more than 6 months).

Most patients need the longer treatment plan, which has an excellent history going back many years. Before surgery, with the patient fully awake or during an earlier office visit, a prudent clinician planning mandibular implants will conduct a neurosensory examination to rule out altered sensation, thus setting a base line on nerve function. Also prior to surgery, a panoramic X-ray will be taken using a metal ball of known dimension so that calibrated measurements can be made from the image (to accurately locate "vital structures" such as nerves and the position of critical anatomical features such as the mental foramen, which is the transit point in the jawbone for the nerve which innervates the lip and chin).

At edentulous (without teeth) jaw sites, a pilot hole is bored into the recipient bone, taking care to avoid vital structures (in particular the inferior alveolar nerve or IAN within the mandible). A zone of safety, usually 2 mm, is the standard of care for avoiding vital structures like the IAN. When computed tomography (3D X-ray imaging) is used preoperatively to accurately pinpoint vital structures, the zone of safety may be reduced to 1 mm through the use of computer-aided design of surgical guides.

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 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.

Once properly torqued into the bone, a cover screw is placed on the implant, then the gingiva or gum is sutured over the site and allowed to heal for several months for osseointegration to occur between the titanium surface of the implant and jawbone.

After several months the implant is uncovered in another surgical procedure, usually under local anesthetic by the restorative dentist or prosthodontist, and a healing abutment and temporary crown is placed onto the implant. This encourages the gum to grow in the right scalloped shape to approximate a natural tooth's gums and allows assessment of the final aesthetics of the restored tooth. Once this has occurred a permanent crown will be fabricated and placed on the implant.

An increasingly common strategy to preserve bone and reduce treatment times includes the placement of a dental implant into a recent extraction site. In addition, immediate loading is becoming more common as success rates for this procedure are now acceptable. This can cut months off the treatment time and in some cases a prosthetic tooth can be attached to the implants at the same time as the surgery to place the dental implants.

In all of these approaches, computer-based guidance has thrust itself onto the treatment stage. Not only will 3D digital imagery yield critical treatment guidance, the digital data can be used to manufacture precision drilling guides, virtually eliminating surgical errors.

Complementary procedures

Sinus lifting is a common surgical intervention. The trained general dentist, oral surgeon, or periodontist thickens the inadequate part of atrophic maxilla towards the sinus with the help of bone transplantation or bone expletive substance and as a result creates a better quality bone site for the implantation.

Bone grafting will be necessary in cases where there is a lack of adequate maxillary or mandibular bone in terms of front to back (lip to tongue) depth or thickness; top to bottom height; and left to right width. Sufficient bone is needed in three dimensions to securely integrate with the root-like implant. Improved bone height -- which is very difficult to achieve -- is particularly important to assure ample anchorage of the implant's root-like shape because it has to support the mechanical stress of chewing, just like a natural tooth. If an implant is too shallow, chewing may cause a dangerous jawbone crack or full fracture.

Typically, implantologists try to place implants at least as deeply into bone as the crown or tooth will be above the bone. This is called a 1:1 crown to root ratio. This ratio establishes the target for bone grafting in most cases. If 1:1 or better cannot be achieved, the patient is usually advised that only a short implant can be placed and to not expect a long period of usability.

A wide range of grafting materials and substances may be used during the process of bone grafting / bone replacement. They include the patient's own bone (autograft), which may be harvested from the hip (iliac crest) or from spare jawbone; processed bone from cadavers (allograft); bovine bone or coral (xenograft); or artificially produced bonelike substances (calcium sulfate with names like Regeneform; and hydroxyapatite or HA, which is the primary form of calcium found in bone). The HA is effective as a substrate for osteoblasts to grow on. Some implants are coated with HA for this reason.

Bone graft surgery has its own standard of care. In a typical procedure, the clinician creates a large flap of the gingiva or gum to fully expose the jawbone at the graft site, performs one or several types of block and onlay grafts in and on existing bone, then installs a membrane designed to repel unwanted infection-causing microbiota found in the oral cavity. Then the gingiva is carefully sutured over the site. Together with a course of internal antibiotics and external antibiotic mouth rinses, the graft site is allowed to heal (several months).

The clinician typically takes a new panoramic x-ray to confirm graft success in width and height, and assumes that positive signs in these two dimensions safely predicts success in the third dimension, depth. Where more precision is needed, usually when mandibular implants are being planned, a 3D or cone beam X-ray may be called for at this point to enable accurate measurement of bone and location of nerves and vital structures for proper treatment planning. The same X-ray data set can be employed for the preparation of computer-designed placement guides.

Correctly performed, a bone graft produces live vascular bone which is very much like natural jawbone and is therefore suitable as a foundation for implants.

Considerations

For dental implant procedure to work, there must be enough bone in the jaw, and the bone has to be strong enough to hold and support the implant. If there is not enough bone, more may need to be added with a bone graft procedure discussed earlier. Sometimes, this procedure is called bone augmentation. In addition, natural teeth and supporting tissues near where the implant will be placed must be in good health.

In all cases, what must be addressed is the functional aspect of the final implant restoration, the final occlusion. How much force per area is being placed on the bone implant interface? Implant loads from chewing and parafunction can exceed the physio biomechanic tolerance of the implant bone interface and/or the titanium material itself, causing failure. This can be failure of the implant itself (fracture) or bone loss, a "melting" or resorption of the surrounding bone.

The restorative dentist must first determine what type of prosthesis will be fabricated. Only then can the specific implant requirements including number, length, diameter, and thread pattern be determined. In other words, the case must be reverse engineered by the restoring dentist prior to the surgery. If bone volume or density is inadequate, a bone graft procedure must be considered first. The restoring dentist consults with the oral surgeon, trained general dentist, or periodontist to co-treat the patient. Usually, physical models or impressions of the patient's jawbones and teeth are made by the restorative dentist at the surgeon's request, and are used as physical aids to treatment planning. If not supplied, the surgeon makes his own or relies upon advanced computer-assisted tomography or a cone beam CAT scan to achieve the proper treatment plan.

Computer simulation software based on CAT scan data allows virtual implant surgical placement based on a barium impregnated prototype of the final prosthesis. This predicts vital anatomy, bone quality, implant characteristics, the need for bone grafting, and maximizing the implant bone surface area for the treatment case creating a high level of predictability. Computer CAD/CAM milled or stereo lithography based drill guides can be developed for the implant surgeon to facilitate proper implant placement based on the final prosthesis occlusion and aesthetics.

Treatment planning software can also be used to demonstrate "try-ins" to the patient on a computer screen. Software products like Materialise' SimPlant (simulated implant) use the digital data from a CAT scan (such as an iCAT or a NewTom) to provide extremely accurate simulations that are easily understood by patients. When options have been fully discussed between patient and surgeon, the same software can be used to produce precision drill guides.

Success rates

Dental implant success is related to operator skill, quality and quantity of the bone available at the site, and also to the patient's oral hygiene. Various studies have found the 10 year success rate of implants to be between 90 and 95%. Patients who smoke experience significantly poorer success rates.

Failure

Failure of a dental implant is often related to failure to osseointegrate correctly. A dental implant is considered to be a failure if it is lost, mobile or shows peri-implant (after implant) bone loss of greater than 1.0 mm in the first year and greater than 0.2mm a year thereafter.

Dental implants are not susceptible to dental caries but they can develop a periodontal condition called peri-implantitis. The cause may be infection that was introduced during surgery; or failure by the patient to follow correct oral hygiene routines. In either case, inflammation in the bone surrounding the implant causes bone loss (recession) which ultimately may lead to failure, often evidenced by the ability to "spin" an implant.

Peri-implantitis is often dealt with pre-emptively by clinicians who prescribe a course of antibiotics in the days prior to surgery; and post-surgically with another course of antibiotics and special oral rinses. Since peri-implantitis is generally easy to see on standard panoramic and periapical X-rays, prudent clinicians who suspect the problem will take an X-ray soon after surgery, and again at staged intervals post-operatively.

Risk of failure is increased in smokers. For this reason implants are frequently placed only after a patient has stopped smoking as the treatment is very expensive. More rarely, an implant may fail because of poor positioning at the time of surgery, or may be overloaded initially causing failure to integrate. If smoking and positioning problems exist prior to implant surgery, clinicians often advise patients that a bridge or partial denture rather than an implant may be a better solution.

Cost

Price in the United States, implants average around $1,500 per tooth, in addition to the cost of the crown which would then come out to around 4,000 in total(and abutment). The cost of full mouth reconstructions with implants begin around $12000 per arch, and can approach $50000, depending on the complexity of the case.

5 Things You Need to Know About Dental Implants

1. Fill a Gap With a Dental Implant If you lost a tooth and aren't ready for a bridge or the tooth is in the back of the mouth and a bridge is not a viable solution, then a dental implant may be just what the dentist ordered. Dental implants are a form of cosmetic dentistry that uses a prosthesis. A metal screw inserted into the jawbone forms an anchor to which the prosthetic tooth attaches.

2. Most People Qualify Patients with missing teeth whose health is relatively good are candidates for a dental implant. At one time, lack of bone in the jaw stopped the procedure. Today, bone grafts create the additional bone necessary. Even if you have none of your teeth, you are still a candidate for dental implants, although most of the time they replace bridges or a partial.

3. Location, Location, Location Just like real estate, the location of the implant affects the rate of success. Implants in the front don't receive the abuse that the back teeth receive and they have a high success rate, between 90 to 100 percent. The teeth in the back portion of the mouth have a lower rate of success primarily due to the heavy workout and difficulty cleaning the area. Smokers have a lower rate of successful implants than non-smokers. Children are not candidates except in very specific situations.

4. Problems Do Occur The area of the implant may not grow in and hold the screw. Just as a normal tooth, the implant area is subject to periodontal disease if not kept clean. Infection of the area and the surrounding bone is a possibility. There is a small possibility of damage to the jaw or sinus cavitities. An break or loosening is possible for an implant, just like a crown. A strong bite and bruxism create problems with the dental implant. Many oral and maxillofacial surgeons recommend smoking cessation to insure a better result with dental implants.

5. The Good News New coatings for the titanium screw stimulate bone regeneration. Some of the research shows this is far superior to previous plain metal. Dental implants remain in place much better than bridges or dentures. They resemble regular teeth and usually are undetectable. Implants fit into the longer life span that Americans enjoy. The implants are still relatively pricey and may be as much as $2000 or more for a single tooth. Check with a dentist that specializes in this area to get the best results.