Implants: Replacing Human Components[ Essay, Research Paper

The human body is a collection of remarkable biological mechanisms that integrates features that can not be duplicated exactly. However, many modern prosthetic devices can add years to an individual’s life, improve physical comfort and function, or in the case of aesthetic implants, improve emotional health. There are many types of implants that server a variety of functions that offer risks and benefits.

Implants can server many purposes. Cosmetic surgery has variety prosthesis to select from, not only to change the appearance of a feature for aesthetic reasons, but also to correct disfiguring from trauma or disease. Numerous implants are available to enhance physical appearance through cosmetic surgery. Breast implants is one of the most common cosmetic surgery procedures, and is considered extremely useful for reconstruction for breast cancer victims. Aesthetic surgery can improve ones sexual relations due to increase self-confidence. However, cosmetic surgery has also altered the function of genitalia. Implants may also improve sexual function. Although many drugs are available to treat male impotency, surgical penile implantation is an option. An inflatable implant allows the patient to “pump up” the penis before intercourse. Implant devices have also been used in Urology, although with today’s medical advancement, transplantation is now an option. Implants are used for numerous medicinal purposes form pregnancy prevention, vision, hearing, voice or neurological purposes

(Babbush, 112-118). Some other common implantation procedures are prosthetic cardiac valves, hip and knee implants, and dental implants.

Heart valve prosthesis replaces diseased heart valves. There are four valves of the heart: 1) the aortic valve, 2) the mitral valve, 3) the bicuspid valve, 4) the pulmonary valve. These valves are designed to control the direction of blood flow through the heart. The opening and closing of these valves produce the heart beat sounds. When the heart beats, the valves close to keep the blood form flowing backwards. The heart beats more than one hundred thousand times per day. The valves must be able to flex, stretch and hold back pressure hundreds of million times in an average lifetime. The mitral and aortic valves are on the left side of the heart. These are most commonly affected by aging because the pressure is higher on this side. The right heart valves can be damaged by infection or lung disease. Regardless of the valve damage, as they harden or weaken they do not open properly and therefore blood flow may be blocked. Heart valve conditions may also be congenital. Diseases such as rheumatic fever or bacterial infections may also scar or destroy the valves. Heart valve diseases fall into two categories, stenosis and incompetence. The stenotic heart valve prevents full opening of the valve because of the stiffened valve tissue, therefore the heart works harder to push blood throughout the valve. The incompetent valve cause insufficient blood circulation by permitting backflow of blood on the heart. There are two main types of prosthetic valve designs: mechanical and bioprosthetic (tissue). Mechanical heart valves were first implanted in 1952. Since then, over 30 different mechanical designs have originated. The material used to no cause clotting in the blood stream, however, they do not induce coagulation. Most commonly used materials include: stainless steel alloys, molybdenum alloys, pyrolitic carbon, silicone, teflon, and polyester for sewing rings (Summerscale, 2-4). The advantages of mechanical valves are their high durability. They typically last the lifetime of the patient. The disadvantages include the increase risk of blood clotting, which in turn increases the risk for heart attack or stroke. Therefore, mechanical valve recipients must take an anticoagulant drug chronically, which could make the patient borderline hemophiliac. The bioprosthetic valves may be either human tissue or animal tissue from pigs or cows. The rate of success of heart valve surgery is high. The death rate varies depending on heart valve, which averages two to three percent. Approximately two out of three patients who receive artificial mitral valve are still alive years after surgery (WebMD, 1-3). An article published in the Journal of the American Dental Association explains the American Heart Association has listed prosthetic cardiac valves in the high-risk category for bacterial endocarditis during invasive dental procedures and requires the patient premedicate before treatment (Rothwell and Tong, 369).

Hip replacement surgery, also called arthroplasty, is one of the most successful operations available for orthopedic surgeons. The goal of hip replacement surgery is to remove the diseased parts that cause pain and improve function the hip joint. One of the most common reasons people have hip surgery is due to the wearing down of hip joint that results in osteoarthritis Rheumatoid Arthritis, Avascular Necrosis, injury or bone tumors. These conditions may lead to the breakdown of the hip joint. The usual hospital stay for hip replacement surgery is approximately three to five days. The procedure itself takes two to four hours. During hip replacement, the disease bone tissue and cartilage are removed. The surgeon replaces the head of the femur (the ball) and the acetabulum (the socket) with new artificial parts. Sometimes the surgeon uses special glue or cement, to bond the new parts of the joint to the existing healthy bone. This is known as a cemented procedure. In an uncemented procedure, the artificial parts are made of porous material that allows the patients bone to grow into the pores and hold the new parts in place. According to the American Academy of Orthopedic Surgeons approximately one hundred and twenty thousand hip replacement operations are performed each year in the United States and less than ten percent require further surgery (WebMdHealth, 1-5).

The most common problem after hip surgery is hip dislocation. The most dangerous position to cause this is to pull the knees into the chest. Another complication may be caused by the loosening of the implant. A revision surgery may be recommended at this point. Other complications may include infection, blood clots, hetrotropic bone formation (bone growth beyond normal edges of bone). Some patients may require blood after surgery. Patients are being advised to do an autologous blood donation before surgery. About one to ten patients develop a blood clot that travels to lungs, causing difficulty breathing (1 in 1000 patients) and possibly death (1 in 10,000 patients). Approximately one in two hundred fifty patients will develop a deep infection around the artificial hip components. If this occurs, removal of the implant may be necessary. If the infection is treatable and dissipates, another implant may be placed, if not, fusion is required. Because the large risk of infection, many physicians require their patients to premedicate with antibiotics before dental procedures. Large amounts of bacteria in the mouth increase the opportunity of infection to travel to the implant. Dental precautions are not only necessary after implant surgery, but also it is important to have a complete dental exam before hip replacement surgery. If Dental infections are present, such as a dormant abscess, it is necessary to be treated before surgery to prevent the spread of infection (WebMdHealth, 1-7).

Due to medical progression over the past twenty years, knee replacement surgery has equaled or even surpassed hip replacement surgery. Based on pain, motion and function ability the results are excellent in ninety percent of the cases. In sixty percent of the cases were able to eliminate all of the pain. In only ten percent of the cases patients may continue to have pain, requiring medication. Not all implants last for twenty years, but if the original bone cuts were conservative enough, a second implant is placed. The orthopedic surgeon makes an incision over the infected knee. The patella (knee cap) is removed. Then the heads of the femur and tibia are shaved to eliminate any rough spots and permit better adhesion to the prosthesis. The two parts of the prosthesis are implanted into the thighbone and the tibia bone using special cement. Knee joint replacement may be recommended for any of the following conditions: constant knee pain over an extended period of time, osteoarthritis or arthritis, knee fractures or tumors. Morbid obesity (over 300lbs), which may be the cause of functional breakdown, is a contraindication for knee replacement. Complications and risk involve with knee replacement surgery are deep venous thrombosis, hemotoma, loosening and fracturing

(Fu, Harner, Vince, 1240-1245).

The hospital stay is relatively short. Cruches may be necessary for about three months after surgery. Physical therapy starts in the hospital and is usually continues after release. Knee implants have the same risk of infections as hip implants. Many physicians recommend the same precautions. According to the JADA, the AAOS and the ADA have recommended the use of prophylactic antibiotics only for patients with total joint replacements (not for patients with only pins, screws or plates) and compromised immune systems (Rothwell and Tong, 369).

Missing teeth have long been a dilemma for mankind since their existence. The solution to this dilemma has evolved over many years. Dental Implants have changed to become a more acceptable form of treatment for tooth replacement. Dental Implants are biocompatible substitutes for lost natural teeth. Fossil evidence suggests that as early as two thousand years ago, ideas for tooth replacement were implemented. Teeth were replaced by alloplastic or homologus materials such as human or animal teeth, carved human and animal bone, fragments of ivory, and mother of pearl and other materials. About one thousand years ago Spaniards replaced teeth by transplantation. Several hundred years ago in France and England, lost teeth were obtained from young adults who were paid for their extracted teeth. However, infectious diseases such as syphilis and tuberculosis were transferred as well. Over the years, many treatments were suggested but failed. In 1952, in a laboratory in the town of Lund, Sweden, a Professor Per-Ingvar Branemark discovered that is was impossible to recovery any of the bone anchored titanium microscopes he was using in his research. It appeared as though titanium bonded irreversibly to living bone tissue. This observation would later become the bases for the modern dental implant. He realized that under carefully controlled conditions, titanium could be structurally integrated into living bone, Branemark named this phenomenon osseointergration. By 1965, the first practical application of osseointergration were placed in patients. More than thirty years later, the non-removable teeth were function perfectly. The American Dental Association accepted the concept in 1986 (Slavkin 1-8).

There are three types of implants. One fits on top of the bone, which is called subperiosteal implant. This implant actually does not go into the bone. It sits on the bone and is covered by the tissue. This type is useful if there is a lack of bone. Another type of implant is Endosteal. There are different sizes and shapes. They may be shaped like cylinders, flat or even blade like. The choice of what implant is used depends on the quality and amount of available bone and type of prosthesis desired. Transosseous implants are the third type. These implants are similar to subperiosteal except they actually penetrate the jaw so that they emerge on the opposite site of insertion, usually at the base of mandible. However, these implants are rarely used (Gougaloff, 1-9).

Patient selection is an important ingredient to the success of the procedure. A complete and thorough medical history must be completed and evaluated before the procedure is considered. Systemic conditions that may affect the success of the implants are numerous. Diseases of Cardiovascular system are given careful consideration and prophylactic use of antibiotics and consultation with the patient’s physician is recommended. Gastrointestinal System disorders include symptoms such as vomiting, hypersecretions, xerostomia, and hyperacidity, which can contribute to changes in saliva PH that may alter the healing of the mucous membranes. Various ulcers of the GI tract can reflect the amount of stress in a patient’s life. This same stress can manifest into bruxism, which can lead to implant failure. Disorders of blood such as hemophilia are not suggested for dental implant treatment. Patients taking anticoagulants are also consider poor implant candidates. Other medical conditions such as immunological suppressed diseases such as HIV or diabetes must be taken into consideration, because they affect the healing ability of oral mucosa (Babbush, 1-32). Other conditions such as osteoporosis, diabetes, and long term medications such as corticosteroids, immunosuppressants, nosterodial anti-inflammatory drugs and antibiotics can also effect the success rate. Also poor general health and collagen related connective tissue disorders such as sclerodoma, Sjogrens Syndrome, Rheumatoid Arthritis are considered to be contraindicated for implant treatment. Smoking is believed to also cause implant failure. Dental radiographs are also an important factor to determine the bone contour and quantity in selecting a candidate. Most patients who are healthy and undergo normal dental treatment and maintain good oral hygiene can have dental implants. Individual evaluation is necessary to determine the success rate of the surgery (Slavkin, 2-4).

There are two methods of implantation. The first involves two stages: the surgical stage and restorative stage. In the surgical stage the implants are placed and 4-6 months to allow osseointergration. The implant is then uncovered from gingiva and healing caps are placed for about 3-4 weeks. The implants are now ready for the restorative stage with prosthetic devices such as crown, bridges, or over dentures. The other method involves a single stage that only requires one surgical procedure in which the fixture is inserted immediately at the same appointment the implants are placed. This is new and experimental application of Dental Implants and the success rate is still to be determined. (Gougaloff 1-4).

Most of the possible complications associated with implant surgery are not serious. Other than the unlikely situation of a severe infection or fracture of the bone, most problems are easily reversed by medication, surgical intervention or removal of the implant. Sometimes the implant can be placed in the same location, or it can be placed in another location. All surgical procedures have certain risks, although complications are unlikely. Surgery on the lower jaw may incur a risk of damaging the nerve, which controls sensation of the lower lip. If the nerve is damaged, there could be a loss of or change of feeling in the lower lip and chin. This change in feeling might involve tingling, itching, burning, feeling cold, feeling hot, or feeling partially or completely numb. Damage to the nerve is not likely. If it does occur, the feeling will usually return gradually to its normal state within a few weeks to a few months. However, if the nerve it is possible that the resulting numbness could last for years or be permanent. Surgery on the upper jaw could result in nerve damage to the corner of the nose or placement of implants in nasal passages or sinuses. After corrective surgery, these conditions usually subside after antibiotic treatment (Gougaloff, 1-9).

Oral hygiene of the implants can determine the success or failure of a dental implant. The Dental Hygienist’s role in Dental Implant success is the imperative, not only instructing the patient on proper hygiene techniques, but using proper instruments and instrumentation. Natural teeth are connected to bone by numerous periodontal fibers. These fibers do not exist with an implant, instead circular fibers provide by keratinized gingiva surrounding the dental implant provides a tension referred to as the perimucosal seal. The implant is integrated directly into the bone by osseointergration. Without periodontal ligament, the implant lacks sensory advantages of natural teeth. The implant is unable to adapt to occulsal trauma. Trauma can result in fractures of bone or bone resorption. Warning signs such as chronic screw loosening of the screw-retained prosthesis, porcelain fracture, unseating of attachments, excessive occlusal wear, denture sore, purulence, redness, swelling and patient discomfort may be apparent with occlusal trauma. Trauma over a period of time may be the causative factor for necessary removal of the implant and result in failure (Harris, 2).

The purpose of the perimucosal seal is to barrier from outside components rather than support or strength. Therefore probing implants must be done with extreme care. Actually probing isn’t necessary when tissue is healthy and bone levels are radiographically normal. If probing is necessary, to validate inflammation, the probe should never disturb the perimucosal seal between the soft tissue and the implant. Excessive probing could possibly disrupt attachment. As with instruments used for prophylaxis, only plastic probe should be use. A metal probe may scratch the implant creating an uneven surface allowing a haven for bacteria to exist. Acceptable instruments for implant debridement may be plastic, resin, graphite, or gold-tipped scalers. A soft-tip plastic sleeve placed on the tip of the sonic scaler or ultrasonic scaler does not damage the implant and is effective in debriding the area. When polishing us a rubber cup and a low abrasive polishing paste of tin oxide, Glo polishing past or Nupro fine polish. Implant patients should be put on a more frequent recall, most are put on a three-month recall. Proper maintence from the patient and hygienist play a key role in the success of Dental Implants (Harris, 5-10)

Loosing teeth can be embarrassing, traumatic experience. Not only is the ability to chew lost, but it can also affect self-esteem. It can alter lifestyles. Dentures often are not a exact replication of natural teeth esthetically or functionally. Often patients also wearing an upper denture may have trouble tasting food because the palate is covered. Implants are a proven solution for one or even an edentulous patient. Instead of reducing adjacent teeth for abutment attachments for a bridge, a single implant can be inserted. Removable partials also use clasp and rest, which have to be carved into teeth. As the pressure of chewing is exerted, the partial rocks back and forth. This can cause the teeth to loosen, causing them to be lost over a period of time due to trauma. If the patient is already edentulous and wearing dentures, implants can still improve the anchorage and prevent dentures from wobbling or clicking allowing the patient to eat foods that were impossible without the extra support of implants.

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