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Implantation. Definition Materials used for dental implant. Types of dental implant Osseointegration Biomechanics of osseointegrated implant. Introduction To Dental Implant. Oral Implant:.
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Definition Materials used for dental implant. Types of dental implant Osseointegration Biomechanics of osseointegrated implant. Introduction To Dental Implant
Oral Implant: A device or inert substance, biologic or alloplastic, that is surgically inserted into soft or hard tissues, to be used for functional or cosmetic purposes.
Oral Implant: • A permucosal device which is biocompatible and biofunctional and is placed within mucosa or, on or within the bone associated with the oral cavity to provide support for fixed or removable prosthetics.
Introduction • Losing tooth/teeth is not new problem • It is possible to replace teeth that look & function like natural teeth • Implants is one of the means of achieving this through osseointegration (biological adhesion of bone tissue & titanium) • Pioneered by prof. Per-Ingvar Branemark in 1952 ( Swedish orthopedics' surgeon)
Advantages & disadvantages of implant over conventional treatment • Implants do not involve preparation of the adjacent teeth, they preserve the residual bone, and excellent aesthetics can be achieved. • However, it is expensive, the patient requires surgery, time consuming, and technically complex.
Types of dental implants • 1. Mucosal Insert • 2. Endodontic Implant (Stabilizer) • 3. Sub-periosteal implant • 4. Endosteal or Endosseous implant • Plate-form implant • Ramus-frame implant • Root-form implant 5. Transosseous implant
Root Form Implants In this presentation we will focus on the Root Form Implants.
Since the introduction of the osseointegration concept and the titanium screw by Dr. Branemark, these implants have become the most popular implants in the world today.
Root form Implants come in a variety of shapes, sizes, and materials and are being offered by many different companies worldwide. Some clinicians regard them to be the Standard of Care in Oral Implantology. • These implants can be placed wherever a tooth or several teeth are missing, when enough bone is available to accommodate them. However, even if the bone volume is not sufficient to place Root form Implants, Bone grafting procedures within reasonable limits should be initiated, in order to benefit from these implants.
Root form implant shape: • Other variations dwell on the shape of the Root form implant. Some are screw-shaped, others are cylindrical, or even cone-shaped or any combination thereof.
Today, the most accepted material for dental implants is high grade Titanium—either CP Titanium or an alloy thereof. The titanium alloy implants tend to be stronger than the CP titanium implants. The bone integration shows no difference to the two different types of titanium. • Some implants have an outer coating of Hydroxyapatite (HA). Other implants have their surface altered through plasma spraying, or beading process. This was developed to increase the surface area of the titanium implant and, thus, in theory, give them more stability. These surface treatments were also offered as an alternative to the HA coatings, which on some implants have shown to break loose or even dissolve after a few years.
Osseointegration A time-dependant healing process where by clinically symptomatic rigid fixation of alloplastic materials is achieved, and maintained, in bone during functional loading. (Zarb & Albrektson,1991)
Factors affecting osseointegration • Implant biocompatibility • Implant design • Implant surface • Implant bed • Surgical technique • Loading condition
Bone QualityAccording to Lekholm and Zarb.,1985 • Quality I Was composed of homogenous compact bone, usually found in the anterior lower jaw. • Quality II Had a thick layer of cortical bone surrounding dense trabecular bone, usually found in the posterior lower jaw. • Quality III Had a thin layer of cortical bone surrounding dense trabecular bone, normally found in the anterior upper jaw but can also be seen in the posterior lower jaw and the posterior upper jaw. • Quality IV Had a very thin layer of cortical bone surrounding a core of low-density trabecular bone, It is very soft bone and normally found in the posterior upper jaw. It can also be seen in the anterior upper jaw.
Surgical technique • Minimal tissue violence at surgery is essential for proper osseointegration. Careful cooling while surgical drilling is performed at low rotatory rates. Use of sharp drills. Use of graded series of drills. Proper drill geometry is important, as intermittent drilling. The insertion torque should be of a moderate level because strong insertion torques may result in stress concentrations around the implant, with subsequent bone resorption.
Loading condition • Delayed loading: • A tow-stage surgical protocol • One-stage surgical protocol Immediate loading: • Immediate occlusal loading (placed within 48 hours postsurgery) • Immediate non-occlusal Loading (in single-tooth or short-span applications) • Early loading (prosthetic function within two months)
Biomechanics of osseointegrated implant • In all incidences of clinical loading, occlusal forces are first introduced to the prosthesis and then reach the bone implant interface via the implant. So far, many researchers have, therefore, focused on each of these steps of force transfer to gain insight into the biomechanical effect of several factors such as • Force directions and magnitudes, • Prosthesis type, • Prosthesis material, • Implant design, • Number and distribution of supporting implants, • Bone density, and • The mechanical properties of the bone-implant interface.
Dental Implant Treatment Planning and Types of Dental Implants How many teeth are missing? What is the degree of bone loss? Are the remaining teeth in a good position and do they have a long-term prognosis? What does the patient expect for an end result? What treatment will result in the best cosmetic outcome? What is the patient's budget?
Overall What is the most practical and feasible implant treatment that will produce optimal chewing function and optimal cosmetic results in a timely and affordable manner?
Diagnosis and Treatment Planning • The evaluation of a patient as a suitable candidate for implants should follow the same basic format as the standard patient evaluation, although some areas require additional emphasis and attention: • Medical History. • Psychological Status. • Dental History.
Diagnostic phase Problem list & treatment considerations • radiographic analysis • surgical analysis • esthetic analysis
The superstructure for completely edentulous patients can be classified as follows: • Implant retained removable overdenture • Implant supported removable overdenture • Fixed detachable prosthesis (Hybrid prosthesis) • Implant supported Fixed Bridge • 1) Screwed-in Fixed Bridge • 2) Cemented Fixed Bridge
Treatment Plan Selection • Treatment planning and the decision-making process is a balance between the patient’s preferences, finances and clinical factors. • Understanding that cost is an initial barrier to case acceptance, a large percentage of patients may reject more expensive options that only include fixed prostheses.
Treatment Planning Determinants • 1. Changes in Oral Structures in Edentulism • 2. Posterior Ridge Anatomy • 3. Occlusal Forces • 4. Quality, Location and Quantity of Bone • 5. Implant Size • 6. Implant Location • 7. Arch configuration • 8. "Mapping" the Mandible • 9. Cantilevering
1. Changes in Oral Structures in Edentulism • With successive denture treatments, it is common for the vertical dimension of occlusion to decrease as bone resorbs. This promotes an increased tendency toward a skeletal Class III relationship.
2. Posterior Ridge Anatomy • Posteriorly, poor ridge height, inadequate attached gingiva and compromised ridge shape cause increased horizontal movement of the prosthesis. This increases the lateral forces that are brought to bear on the anterior implants, and will affect bar and prosthesis design.
3. Occlusal Forces • The maximum bite force of subjects with a mandibular denture supported by implants is 60 to 200% higher than that of subjects with a conventional denture • Edentulous patients that are predisposed to clenching and bruxing may be given the necessary "tools" to begin parafunctional habits once the implant bar is secured in place.
4. Quality, Location and Quantity of Bone • The minimum buccal-lingual thickness of osseous tissue required to successfully place an implant is 5 mm. • In order to achieve a 5.0 mm "flat" base, either the anterior ridge crest peak must be removed or a bone graft must be considered.
5. Implant Size • The greater the surface area of the implant-bone system, the less concentrated the force transmitted to the crest of bone at the implant interface. Similarly, the greater the surface area of the implant-bone system, the better the prognosis for the implant. • For each 0.25 mm increase in diameter, the surface area of a cylinder increases by more than 10 per cent; • For each 3.0 mm increase in length , the surface area of a cylinder increases by more than 10 per cent.
6. Implant Location • Ideally, occlusal forces should be directed along the long axis of the implants. Therefore ,The angle of the osseous ridge crest is a key determinant of implant angulation. • the distance between an implant and any adjacent "landmark" (natural tooth or another implant), which should be not less than 2.0 mm.
7. Arch configuration • Mandibular arch forms may be classified as tapered or square. • With tapered arch forms, the most posterior right and left implants in a four-implant treatment are often placed well around the "turn" of the arch, creating a "U" shaped design that is well suited to cantilevering, • With a square arch, the four implants are usually placed in a relatively straight line. This "straight line" bar design is not well suited to cantilevering.
8. "Mapping" the Mandible • The anterior symphysis can be divided into five geographic sites: • A point, 6.0 mm anterior to each mental foramen, determines the most posterior boundaries, right and left. • Another possible implant location occurs at the midline. • Two additional sites are chosen on each side of the midline, spaced equidistantly between the midline and the respective distal sites.
9. Cantilevering • The number of implants, their respective lengths and locations, the quality of bone support, the posterior ridge anatomy, occlusal forces, and the opposing dentition are of greater importance in determining the appropriate cantilever than a suggested formula. • One method is to draw a line through the most anterior implant, and another through the two most posterior implants. The distance between the two lines can then be measured. A suggested maximum cantilever would be 1.5 times this distance.
TreatmentPlanning • When all the diagnostic information has been assembled, a variety of available treatment options must be assessed: • 1. One-Implant Overdenture • 2. Two-Implant Overdenture • 3. Three-Implant Overdenture • 4. Four-Implant Overdenture • 5. Five-Implant Overdenture
Outline • Why are dentists moving to dental implants ? • Successful dental implant. • Indications for dental implants.
Advantages of dental implants: • Preservation of tooth structure. • Preservation of bone. • Provision of additional support. • Retrievability. • Resistance to disease. • Increased confidence. • Improves aesthetics, function and speech. • Conclusions • References.
Why are dentists moving to dental implants ? • Address patient’s needs and requests. • High success rate. • Progressive development of new implant systems, Diagnostic procedures, and the introduction of novel surgical techniques.
Advancement of technical procedures (CADCAM). • Many training courses are offered by universities, professional societies and implant manufacturers. • Profitable.
Successful implant • Successful Osseointegration.
Successful implant • Restoration of normal contour, aesthetic, function and speech.
Successful implant • Clinically: • Immobile. • No persistent pain, infections, paresthesia or neuropathies.
Successful implant • Radio-graphically : • No peri-implant radiolucency. • Vertical bone loss should be less than 0.2 mm annually following the implant’s first year of service.
Indications for dental implants. • Intolerance to removable dental prosthesis. • Need for long span fixed prosthesis with questionable prognosis. • Single tooth loss that will make it necessary to prepare sound adjacent teeth for a fixed prosthesis. • Unfavourable condition, location and number of abutment teeth.
Advantages of dental implants • Preservation of tooth structure. Fixed bridge Implant
Advantages of dental implants • Preservation of bone. loss of teeth→ Lack of stimulation to the residual bone→ Decrease in bone density, height and width.
