Loss of teeth is major healthcare and aesthetic concern among the older adults as it compromises their general health, profile, and personality thereby affecting their overall quality of life.
Researchers conducted a survey among the older adults to know about their expectations regarding the replacement of their lost teeth.
Most of the population suggested a reliable and effective replacement that is more natural. This led to the rise of the field of dental implantology based on the concept of osseointegration.
Over the years dental implants have gained a number of transformations giving most accepted, reliable and effective outcomes than the other replacement methods. The article describes in detail about the procedures involved in dental implants, pre/post-operative care and follow up.
PATIENT SELECTION CRITERIA:
Evaluation and selection of the patient plays an important role in a successful implant that stays for long term.
Dentist must thoroughly assess the patient and inform them regarding their state. A successful implant is achieved by the coordination of the patient and the dentist.
Checklist for evaluation:
- Record a complete medical history.
- Obtain a dental history.
- Habits (smoking, alcohol, etc).
- Diet and allergies.
- Any history of systemic illness.
- Socioeconomic status.
- Patient’s expectation regarding replacement.
- Clinical examination.
- Previous photographs to examine the profile.
- Radiographical examination.
During clinical examination dentist should check for the following:
- Any soft tissue outgrowth or overgrowth.
- Bony projections or spikes that interfere with the dental implant.
- No. of edentulous spaces.
- Supporting / abutment teeth.
- Habits like grinding of teeth and Bruxism.
- Periodontal diseases.
- Recurrent soft tissue lesion/ulcers.
Care should be taken to evaluate multiple views of the edentulous space to analyze the bone pattern.
- Bone height and width.
- Bone density.
- Bony defects like dehiscence & fenestration.
- Inferior nerve canal association with the site of implant placement.
- Distance from the crest of the maxillary ridge till the base of the maxillary sinus.
- The health of the abutment teeth.
- Any underlying jaw bone cyst/tumors.
There are no absolute contraindications for dental implants but their rate of success and longevity becomes questionable in the following cases:
- Jaw bone defect.
- Patients under Radiotherapy.
- Before/after tumor resection.
- Cardiovascular, liver diseases, renal dysfunction, lung diseases, bone & bleeding disorders.
- Mentally impaired individuals.
- Incomplete jaw growth.
- If the implant does not satisfy the esthetic demand of the patient.
IMPLANT SELECTION CRITERIA:
Dental implant differs in the material, shape, diameter, length, and type.
A patient-specific selection is needed and the implant design needs to achieve important factors like esthetics, retention, stability, and restoration of the function.
The manufacturer provides a variety of dental implant designs.
They basically fall into the following:
- Wide dental implants.
- Narrow dental implants
- Basal implants.
- Zygomatic implants.
Wide dental implants:
Most of the implants available in the market are wide implants. The diameter of the implant varies accordingly from 3.6mm to 4.5mm or more depending upon the manufacturer.Tweet
They provide a greater surface area for osseointegration and stability. They are indicated in immediate loading and in compromised anatomical situations. They have a good survival rate even when placed in a compromised bone.
Narrow dental implants:
The diameter of the narrow dental implants ranges from 3.3 to 3.5mm. These are indicated for single-tooth restoration in a non-loading region with decreased alveolar crestal bone, replacement of the front teeth & decreased inter radicular bone.
They have a success rate of 90.9% to 100%.
It is a single implant body or single piece implant with the abutment fused together driven into the basal bone.
It is indicated mostly in the mandible with multiple teeth extraction. The body of the implant is thin with wider threads for enhancing the osseointegration.
The abutment head attached to the implant is available from different angles ranging from 15 to 25 degrees.
- Bone augmentation failure.
- Thin ridge with deficient bone thickness.
- Insufficient bone height.
- Single piece implant.
- Provide good basal – cortical bone support.
- Survives even in compromised bone situations.
- Distributes the masticatory forces.
- Decreased incidence of peri-implantitis.
It is indicated in completely edentulous patients with severe atrophy of the maxillary bone.
The implant is approximately 11mm or more and directly driven into the Zygomatic bone from the region between the 2nd premolar and first molar (site may vary according to the patient’s morphology).
This implant involves a 3D Radiographical examination to evaluate the site of the implant placement and the position of the maxillary sinus as it passes through the sinus.
It is done under general anesthesia in an operation theatre assisted by an anesthetist. Pre-operative evaluation and fitness report of the patient is collected from his / her physician and the assisting anesthetist.
Team evaluation and planning is necessary. The two Zygomatic implants are usually combined with 2 or 4 anterior maxillary implants.
It is contraindicated in acute sinusitis, Zygomatic bone pathology, chronic smokers or any systemic illness.
Checklist to evaluate before the implant surgery:
- Ridge splitting and bone expansion.
- Maxillary sinus – lift procedure.
Osteoplasty: It is the reshaping or remodeling of the bone to remove the interferences without damaging the tooth-supporting bone.
The procedure is done under local anesthesia. Elimination of the knife-edge ridge and flattening of the crestal bone is done to increase the longevity of the dental implant.
It is usually done prior to the implant placement after the elevation of the flap. For example tori removal, heavy ledges or exostosis removal.
Ridge splitting and bone expansion: Mostly indicated in maxillary bone than mandible under local anesthesia.
The ridge should have an adequate vertical bone with cancellous bone in between the labial and palatal cortical plates.
A uni-beveled chisel, bibeveled and tapered osteotomes are used with a gentle tap using a mallet after the flap reflection on the site of the implant placement. With the chisel and osteotomes used the ridge expansion is carried out without cracking the labial cortical plate.
After desired expansion implant drills are driven for the desired implant size and the flap is closed after implant placement.
Bone Grafting: A graft is a living tissue that is placed as a replacement into the patient surgically in order to restore the lost tissue.
A bone graft takes up to 6 to 12 months for augmentation. Graft placement is don’t under local anesthesia. Grafts can be of the following types:
Autograft: The graft tissue is extracted from one location and transplanted in another site in the same individual. The bone grafts used are clavicle, Ramus of the mandible, iliac crest, etc.
Allograft: The graft tissue is obtained from a donor of the same species. They are taken from cadavers or donors.
The graft is demineralized and available as fresh dry bone grounded granules, block bone or in segments. The allograft is usually preferred in dentistry.
Xenograft: The graft tissue is obtained from another species. For example bovine bone (they are large in volume and particle size).
Synthetic graft: Artificial bone grafts can be made with combinations of hydroxyapatite and tricalcium phosphate.
These grafts result in high bone density after grafting them.
Maxillary sinus-lift technique: This technique was 1st described in 1994 done under local anesthesia.
It is indicated when there is decreased bone height in the maxilla (residual bone thickness less than 5mm) or the remaining alveolar bone thickness from the crest of the ridge is close to the base of the maxillary sinus or its septa.
It is contraindicated in patients with acute sinusitis, systemic illness or infections. The procedure can be of two types; atraumatic maxillary sinus lift & traumatic maxillary sinus lift.
Atraumatic maxillary sinus lift: This can be done with or without the use of bone graft.
The flap is raised on the planned site of implant placement. The osteotome drills are used sequentially until the base of the maxillary sinus or the Schneider membrane is located.
The osteotome is used to lift the membrane without perforating it. The bone drilled out is compacted and the implant is placed without using graft material.
In the event of using a graft material desired height is drilled for the block bone graft material to be placed. Once the graft is secured implant is installed and the flaps are secured with sutures.
Traumatic maxillary sinus lift: This is the classical technique followed for lifting the maxillary sinus membrane.
The patient is given a posterior and anterior superior alveolar nerve block with a palatine infiltration. After anesthesia, a bone window is created in the vestibular region with the osteotome until the Schneider membrane is visible.
Though this technique gives visible access to view the procedure it also has high chances of perforation of the membrane. An elevator is used to elevate the membrane for the bone graft to be compacted till the cavity is completely filled.
It is only indicated when the alveolar bone is severely resorbed or when Zygoma is close to the alveolar bone.
Immediate implant loading is done when there is adequate bone density surrounding the implant or implant is placed after 6 months of the maxillary sinus-lift procedure.
Autogenous cortical bone graft, bovine graft or platelet-rich plasma is mostly recommended bone graft in maxillary sinus lift procedure.
Pre-operative medications: A pre-operative antibiotic dosage is usually prescribed for an hour before the surgery or for a day before the implant surgery. As it plays a vital role in effectively providing an aseptic environment.
Endosseous implants are placed under local anesthesia where as general anesthesia is required for the placement of Zygomatic implants.Tweet
It can be a guided procedure with the help of a template or a non guided procedure. If the template is used it should be placed till the implant placement.
- Develop a patient friendly and comfortable environment.
- Obtain their medical reports to know their current state.
- Check for or maintain a sterile environment.
- Make sure at least 4 additional implants are available i.e. 2 implants greater than the planned size and 2 implants lesser than the planned size.
- Never pull or push the drills when engaged with the bone.
- Don’t create a ditch or side cut.
- Follow the manufacturer’s direction regarding the system of implants being used.
- Follow proper irrigation while drilling to avoid bone degeneration.
Steps in implant placement:
It can be a flap elevated or flapless procedure depending upon the system and the plan of the dental surgeon or implantologist. For example, a drill sequence can be:
- Relieve flap/punch cut to expose the bone.
- The template is placed for a guided procedure through which the drills are passed.
- For a non guided technique template is not required.
- The pilot drill is used to make way for the drills.
- Drill sequence from starts from a diameter of 2mm followed by a diameter of 2.4 mm / 2.8 mm and a diameter of 3.2 mm / 3.6 mm.
- The implant is driven into the bone at a desired torque and rotation.
- Measure the torque to tighten and secure the implant.
- Healing collar or abutment is screwed.
- The flap is secured with sutures.
The patient must be explained about the post-operative and precautions to be followed.
- Must complete a course of antibiotics and analgesics.
- Refrain from wearing dentures after the surgery.
- Refrain smoking, alcohol and other associated products for a week or more.
- Any habit that might cause infection and delayed wound healing.
- Must consume soft and cold foods for a day or two.
- Swelling may or may not be present and regresses after 2-3 days.
- Ice packs are given at intervals only on the day of surgery.
- Rinsing with warm salt water is advised after a day of surgery.
- Don’t pick the site of implant placement.
- Don’t use jet water floss or any mouth rinses with hydrogen peroxide for 2-3 weeks after surgery.
- Post-operative follow-up after 1 week of the surgery.
LONG TERM CARE FOR DENTAL IMPLANTS:
- Regular follow-up at every 6 months interval.
- Proper oral hygiene maintenance.
- Overdentures must be cleaned and maintained.
- Any discomfort must be reported to the dental surgeon.
- Radiographic evaluation of the dental implant for every 6 months.