What are dental implants?
Restoration of function following loss of teeth has been an elusive goal for more than 1500 years. The evolution and advancements in dentistry has enabled the patient to choose from a multitude of treatment modalities for missing and restoring teeth. In 1940’s Dahle introduced sub-periosteal implants and Linkow introduced blade implants later on. In 1980, it was Per Ingvar Branemark who introduced the concept of osseo-integration, which led to the widespread use of endosteal implants. Osseointegration is the direct structural and functional association between ordered living bone and the peripheral surface of a load carrying implant. The advent of dental implants has imparted the same confidence and comfort that a person has with natural teeth as not only does it restore normal oral contour and esthetics but also aids in reconstruction of the atrophied bone and deteriorated soft tissues. A dental implant is a permucosal device that is biocompatible and biofuctional and is placed on or within the bone associated with the oral cavity to provide support for fixed or removable prosthesis. Success of implants entails an intimate contact between the implant and the peri-implant bone surface. Nevertheless, dental implants and peri-implant tissues are affected by diseases and adverse health conditions as do the natural teeth hence require periodic evaluation. Implant dentistry is a multidisciplinary approach involving scrupulous participation of the restorative dentist, oral and maxillofacial surgeon and the dental technician. A dental implant is defined asa material that is inserted into the jaw to reinforce a crown or fixed or removable denture.
Indications for dental implants
- For patients who are completely edentulous and where it is difficult to obtain adequate retention due to advanced residual ridge resorption. In such situations either a fixed or a removal implant supported overdenture can be used. A fixed overdenture is permanently screwed into the implant which cannot be removed by the patient. Such fixed prosthesis is supported by at least four or more implants. The volume of the prosthesis and tissue surface covered is less than the removable prosthesis. It can be either hybrid type or porcelain fused to metal prosthesis. Removal overdentures are prepared in conjunction with attachment systems and require less number of implants for support. A two-implant supported overdenture option is indicated as the first-choice standard of care for an edentulous mandible.
- For patients who are partially edentulous and where weak abutment and reduced masticatory efficiency disregards the use of removable partial dentures. Multiple missing teeth can be either restored with cement retained or screw retained implant. In selective situations when fixed implant supported prosthesis is not feasible then a removable implant supported overdenture which is fundamentally similar to an edentulous prosthesis, can be fabricated. In these situations attachment systems complimenting the function of implants are used.
- For single tooth replacements where fixed partial dentures cannot be placed: A single tooth restoration can be either cemented on to the abutment or screwed into the implant termed as cement-retained and screw-retained restoration respectively.
- Patient’s preference: Some patients may opt for implant over a fixed or removable prosthesis for restoration of missing teeth. Young patients with good oral health and awareness prefer implants as a long term, effective, esthetically pleasing and sustainable treatment option for replacing teeth.
Pre-treatment diagnostic aids
- Periapical radiograph: It aids in evaluation of the amount and quality of bone, root proximity and angulation of adjacent teeth. This technique has certain inherent problems such as distortion of spatial relationships.
- Occlusal radiograph: It helps in assessment of the facio-lingual width of the bone.
- Lateral cephalometric radiograph: It is used to determine the discrepancies in vertical dimension, skeletal inter-arch relationship and the crown implant ratio.
- Panoramic radiograph: It is the most frequently used radiograph for maxillofacial evaluation, locations of important anatomic structures, pathologic features and anatomic variations. It provides information regarding the vertical height of bone, morphology of anatomical structures and the limiting areas. Traditional panoramic radiographs exhibit an inherent magnification of approximately 25%.
- Computed tomography: It gives a detailed view of the cross-sectional topography, angulation and sinus health. It is primarily indicated to determine pre-implantation process evaluation. It is superior to conventional radiography in that superimposition of structures does not occur. The main disadvantage is its cost. Computed tomography can also be used to create a three-dimensional model of the operative site using a computer guided milling machine or Stereo lithography which develops 3D images using two laser beams.
- Diagnostic casts and photographs: Mounted study models and intra- and extra-oral photographs contribute significantly to the treatment planning and outcome assessments. Study models mounted on semi-adjustable articulator simulate a three dimensional working representation of the patient. It assists in the evaluation of occlusal relationships, inter-arch relationships, arch form, anatomy, and symmetry, tooth morphology, and visualization of existing and potential force vectors. Intraoral photographs aid in the evaluation of the soft tissue morphology and discrepancies. Extraoral photographs provide esthetic statistics such as facial form and symmetry, patient’s degree of expression and animation, smile line, buccal corridor display and areas of potential esthetic improvements.
- Measurement of mucosal thickness: It is usually done by piercing the mucosa with a needle on an anesthetized region. It is primarily indicated for the maxillary region. The depth of needle penetration is marked and correlated with the corresponding amount of bone present in the cross-section of the model known as bone mapping. The mucosal thickness can also be measured with special compasses and gauges.
- Rast-O-Pan bite blocks: These are color coded bite blocks which are placed in the patient’s mouth and using video dental sensor bite-wing images of the teeth are obtained. It helps in designing the implant supported prosthesis customized to the patient’s profile.
Types of Dental implants:
Depending on the placement within the tissues:
- Epiosteal implants: They do not penetrate the alveolar bone rather just rest on it, such as the subperiosteal implants.
- Transosteal implants: They penetrate through both the cortical plates and the entire thickness of the alveolar bone.
- Endosteal implants: These implants extend into the basal bone for support. It transects only one cortical plate. It is two types: a root form implant which is used over a vertical column of bone and a plate form implant which is used for a horizontal column of flat and narrow bone. Root form implant is further available in four forms namely Cylinder or press fit form, Screw root form and combination root form.
Depending on the materials used:
- Metallic implants: Can be made up of pure Titanium or an alloy of Titanium, or an alloy of Cobalt Chromium Molybdenum are used.
- Non-metallic implants: Are made up of either Ceramics or Carbon
Depending on their reaction with bone:
- Bioactive implants: have a coating of Hydroxyapatite
- Bio-inert implants: are made up solely of Metals
Based on Prosthetic options of implants:
- FP-1: implant supports a fixed prosthesis that replaces only the crown and simulates a natural tooth
- FP-2: implant supports a fixed prosthesis that replaces not only the crown but also a portion of the root; occlusal half of the crown contour appears normal while the gingival half is elongated or hypercontoured.
- FP-3: implant supports a fixed prosthesis that replaces missing crowns along with the gingival color and portion of the edentulous site; prosthesis contains denture teeth and acrylic gingiva, or it can also be made of porcelain or metal.
- RP-4: implant alone supports a removable overdenture completely
- RP-5: implant and adjacent soft tissue together support the removable overdenture.
Stages of dental implant surgery
- Single stage implant surgery: The implant fixture is placed such that the prosthetic post of the implant extends into the oral cavity. These implants are usually stabilized immediately by inter-implant splints to avoid the action of excessive loading forces on the implant during the healing phase.
- Two stage implant surgery: In this technique a multi-component implant system is used. During the first stage, the implant body is seated in the alveolar bone and covered completely with mucoperiostel flaps. The fixture under the flap is allowed to heal and attach with adjacent bone via osseo-integration. The second stage is done six weeks after the first surgery during which the implant fixture is uncovered so that the prosthetic component can be placed over the implant. This technique offers superior primary stability.
Treatment Procedures of dental implants
- Preparation of surgical stents: A surgical or guiding stent is a prosthetic appliance, which helps to orient and position the implants. It is prepared using compression moulding technique. In case of edentulous arches opposing dentulous ones, the stents are fabricated on the opposing arch and a small wire is incorporated onto the stent along the long axis of the existing teeth.
- Preoperative measures: The surgical site is anaesthetized with or without conscious sedation. The perioral skin is wiped with betadine. Preoperative administration of antibiotics may be given for medically compromised patients and extensive implant cases.
- Implant site exposure: It can be accomplished by flapless surgery or tissue elevation by sulcular, mid-crestal, and vertical-releasing incisions. In patients with excellent preoperative anatomy flapless surgery can be used to provide better esthetic results. In this case the implant and restoration is placed in a single stage.
- Insertion of implant: Insertion procedure varies according to the implant system used. The location of the implant placement site is determined using a surgical stent. Special drills are used under copious irrigation to make space for the implant. Guide pins are used to evaluate the position, spacing, and angulation of the developing osteotomy. The implant body is inserted into the handpiece or mounted on the hand torque wrench and seated into the prepared site. For a single stage implant , an appropriate size transmucosal healing abutment is placed and for the two-stage procedure, an appropriate size cover screw is placed.
- Suturing the flaps: The flap is sutured back into place using either resorbable suture or non-resorbable sutures such as black silk.
- Postoperative radiographs: It aids to evaluate the position of each implant in relation to the adjacent structures and relative to the teeth and other implants.
- Uncovering: It is done in the two stage system. After a waiting period of two to four weeks, the site is reopened to expose the fixture. Impression posts are placed into the implant fixture and an impression is made. The final prosthesis is fabricated with this master cast. Uncovering involves removal of the cover screw followed by replacement with a healing abutment.
- Restoring dental implants: Following adequate healing which may vary from four to six months, the oseeointegrated implant is ready for prosthetic restoration. The intraoral healing caps are removed and the abutment screw is fixed to the implant body. This component helps to retain the final superstructure which can be a crown for single tooth replacements, a fixed or removable prosthesis for replacing multiple teeth, a fixed or removable overdenture for edentulous patients.
Complications/Risk factors associated with dental implant surgery
- Peri-implant diseases: Peri-implant mucositis are inflammatory changes confined to the soft tissues surrounding an implant. Peri-implantitis is progressive peri-implant bone loss in conjunction with soft tissue inflammatory lesion. Peri-implantitis begins at the coronal portion of the implant, while the more apical portion of the implant remains osseointegrated. It is managed via occlusal therapy, implant evaluation, implant design modification, anti-infective therapy, subgingival irrigation and surgical interventions.
- Failure of implants: Failure of implants can occur if the patient develops systemic diseases like diabetes mellitus after implant placement or if the existing systemic condition worsens after implant therapy. Implant surgery is an invasive procedure and all precaution to maintain asepsis should be followed. Infection of surgical site can lead to loss of osseo-integration. Meticulous oral hygiene is a must for the long term success of implants and poor patient compliance leads to implant failure.
Am I a Good Candidate for dental implant surgery?
You can opt for dental implant surgery if you have a single tooth missing, or multiple missing teeth, or a free-end partially edentulous condition, or edentulous with either all mandibular teeth or maxillary teeth absent or both. It is imperative that the patient convey their expectations from the treatment with as a failure of understanding between the patient and their doctor can compromise patient’s satisfaction.
Recovery time and aftercare
Dental implant surgery is a day-care procedure and the patient can go home the same day. Edentulous patients are asked to bite on saline soaked gauze squares for at least an hour. Ice bags and cold compress are used extra-orally for the first 24 hours after surgery. Analgesics are administered for controlling post-operative pain. Operative sutures are removed 7-14 days after surgery. Even if the healing is normal and the prosthesis is essential for esthetics, fabrication of the prosthesis is delayed for at least 14 days after surgery. All patients are scheduled for maintenance visits every three months until advised otherwise.
Success Rate of dental implants
Sandblasted and acid-etched implants have shown a success rate of 99.7% following ten years while Titanium plasma sprayed implants were successful in 89.5% cases following a twenty year period. Anodized implants have demonstrated 96.5% success rate after 10 years and Oxidized implants were 100% successful after 8-10 years. Hydroxyapatite implants had been 93.2–98.5% successful over 4-8 years period.
Benefits of dental implant surgery
- Implant surgery is a reconstructive surgery that aids in replacement of teeth along with the supportive bone, interposed keratinized and mucosal oral soft tissues.
- Restoring the normal contour, comfort, esthetics, and health.
- Implants provide a natural emergence profile i.e. appearance of a tooth as if it is emerging directly from the soft tissues underneath.
- They are more comfortable as the extent of flanges of the final prosthesis can be reduced thus causing less impingement of soft tissues.
- The implant stimulates the bone like a natural tooth thereby preventing residual ridge resorption and preserving bone.
- Restoring and maintaining mastication and speech.
- Properly designed implants can effectively minimize the harmful forces.
- Chewing efficiency is greater than other prosthetics replacements.
- Implants are more stable and retentive due to osseo-integration.
- Eliminate chronic pain related to nerve dehiscence.
- Prevent the potential for pathologic fracture.
Cost of dental implants depends of multiple factors such as: replacement of a single tooth or multiple teeth, span of edentulous arches, full mouth rehabilitation, type and company of implant, type and material of prosthesis, single stage or two stage implant surgery, whether the soft tissues also need to be replaced, correction of inter-arch and skeletal discrepancies. A single implant may cost between $300-450 and the crown approximately $130-300 depending on the material chosen. If a bridge is to be placed, it involves preparation of the adjacent teeth and restoration with crowns that will incur additional crown charges. In edentulous patients a removable or fixed denture is prepared which may cost approximately $300-1150 depending on the type and material of prosthesis.
Why Choose MedcureIndia?
Dental implants are a multistage surgical procedure demanding good patient compliance. Its advantages cannot be overshadowed by the cost. It provides the patient a functional and esthetic simulation of natural teeth enhancing his/her confidence. We at MedcureIndia help you achieve that confidence at cost effective rates. We help you opt from a wide array of implant types and prosthetic materials that is best suited for you. Our adept team of implantologist, oral and maxillofacial surgeon and restorative dentist provide hassle-free quality treatment.
• How much time will it take for the implant site to heal?
Healing of implants with a wide apace around them is comparable to secondary healing of bone fracture, as bone formation occurs via formation of a fibrous and bony callus, at approximately 50-100 micrometers per day. Remodeling of the hematoma occurs by proliferating blood vessels and fibrous connective tissue in 70-14 days. Bone remodeling of the callus is completed by 4-6 weeks. In the mandible, the implants are left undisturbed for 2-3 months, whereas in the maxilla, they remain covered for approximately 4-6 months owing to the slow healing of less dense maxillary bone. During this period the healing bone makes direct contact with the implant i.e. osseointegration.
• Can I brush the implant site while cleaning teeth?
Meticulous oral hygiene is a must for the long term success of implants. Toothbrush with soft round bristles should be used for cleaning. Toothpaste should be only minimally abrasive and the tooth cleaning procedures should be conducted by rinsing or brushing with chlorhexidine. Gauze strips or superfloss are effective for cleaning interproximally. Irrigators can also be used as adjunctive aids.
• What are the disadvantages of implants?
Dental implants are comparatively expensive than the other restorative options. Patient affordability is the primary concern when using implants. It cannot be used in medically compromised patients who are unable to undergo a surgical intervention. It necessitates a longer duration of treatment as is with most of the surgical procedures and some patients may be apprehensive of such tedious fabrication procedures hence patient compliance is an important factor when opting for implants. Recall visits and after care also plays a vital role in implant success. Lastly, it cannot be universally placed due to the presence of anatomical limitations.
• What are the contraindications for dental implants?
Fortunately, there are only a few absolute contraindications for dental implant therapy. Patients who are acutely ill, those suffering from an uncontrollable systemic disease such as uncontrolled diabetes, long term immunosuppressant drug therapy, and patients with certain diseases causing pathologic alteration of the oral mucosa or damage at the potential implant sites unfavorably altering the intermaxillary relationships. As with other surgical procedures, blood dyscrasias and diseases of connective tissue can lead to operative complications hence should be accurately evaluated. Previous radiation to the jaws can lead to postsurgical osteoradionecrosis thus any surgical intervention is avoided during this period. Regional malignancy, metastatic disease, alcohol or drug addiction and severe psychological disorders are universal contraindications for surgical interventions of all sorts.