A dental implant minimizes the loss of sound teeth from adjacent teeth, a remarkable advance in conserving otherwise sound teeth. The dental implant process usually involves a collaborative effort between the restorative and surgical offices, facilitated by a protocol for interdisciplinary treatment planning.
A dentist will do a comprehensive systemic and oral health evaluation of a patient. If there are no oral or other (systemic) health issues that could adversely affect the surgical treatment of the patient, then the dentist will determine why a patient is seeking treatment.
A patient who is seeking a dental implant therapy is based mainly on the following criteria:
- Success rate
- Ability to properly cleanse
Common complaints of patients
- Loose/ill‐fitting dentures
- Denture‐related halitosis
- Mobile/missing teeth
- Unattractive smile/teeth
- Masticatory pain
Central to the dentist‐patient interaction is a preference for what a dental implant can do for the patient and the dentist. In restorative dentistry, the crown generally meets three important criteria:
- Long‐term success rate
- Predictable outcome
- Low‐stress procedure
Implant dentistry fulfills these three criteria even so with the added benefit that the dentist can control the case from start to finish.
Before devising a treatment plan, the dentist should ensure that the patient is financially feasible. Of course, the costs involved in constructing diagnostic models, wax-ups, CT scans, and surgical guides all mount up, even for the simplest cases. If a dental implant or implants are beyond the financial resources of the patient and financing options are not available, then conventional treatment approaches, although less ideal, must be adopted.
It is also necessary to assemble or collect data for the treatment plan. Typically, this involves the following:
- Health HX
- Dental HX
- Cone be-beamed tomography (CBCT) if necessary
- Models if necessary
A dentist will evaluate the implant site, radiographically and visually. Ideally, the dentist will recommend both normal x-rays and cone-beam computed tomography (CBCT) to be used. If CBCT is not available, then “ridge mapping” is a good alternative. Ridge mapping is the process of bone sounding to create a “map” of the bony structure. The vertical and the horizontal dimensions of the bone are assessed to determine if implant therapy is practical. The basic limitation to implant placement is outlined by “the rule of 6’s.”
Criteria for satisfactory implant placement:
- 6mm radiographic height
- 6mm of bone width (determined from CBCT or ridge mapping)
- 6mm mesial/distal space
- 6mm inter-occlusal space Implant site accessibility
If these criteria are not met, bone augmentation (bone grafting) can be performed. Bone deficiencies occur for multiple reasons but are primarily due to bone resorption or bone loss over time following an extraction.
Deciding which implant to use is often a matter of personal choice, there is an abundance of implant systems available to the practitioner. The final decision on implant system selection lies with the dentist but will be impacted by the implant site, the operative conditions and the type of restoration to be placed on the implant(s).
Implant selection criteria:
- Implant design
- Bone level relative to coronal implant position
- Internal connection • Long‐term availability of parts
- Platform switch (horizontal offset)
- Abutments to allow a multitude of restorative choices
If sufficient bone exists, it must be determined whether the implant can be restored properly. Things to consider include the absence or presence of the opposing teeth as well as their condition. Also, the practitioner must consider the angle at which the implant will be placed. Ideally, the implant should be placed along the long axis of the final restoration. If there is excessive off‐angle loading, bone loss or restorative failure may occur.
Implant Site Evaluation – Healed Bone
Endosseous implants are used in edentulous areas where there is sufficient healthy bone to accommodate the implant without risk of damage to vital structures. Endosseous implants are contraindicated in situations where there has been excessive ridge resorption. Other contra‐indications for endosseous implants include severe malocclusion, bruxism, and parafunctional oral activities such as pipe or pencil chewing. The practitioner may decide to undertake treatment when certain criteria are satisfied.
Implant Site Evaluation – Immediate Site
When evaluating a potential extraction/immediate implant placement site, the dentist must evaluate the following:
- Absence of any active infection
- Intact buccal plate
- The likelihood of an atraumatic tooth extraction
- The existence of all walls of bone (Buccal, Lingual/Palatal, Mesial, Distal)
- Sufficient vertical height of bone between the implant site and vital structures
- Insertion torque – of about 25Ncm
If these criteria are not met, it is best to perform socket preservation and thus delay implant placement. Although placing a single implant in a healed site is perhaps the most straightforward of implant procedures, practitioners can run into problems and situations that need to be addressed appropriately to achieve a successful outcome.
Replacing a missing or extracted single (free-standing) tooth is the most common implant procedure performed. It is the most basic implant procedure in that there is no need for the preparation of abutment teeth for a traditional bridge. Even though this procedure is surgical, it is less invasive in that removal of enamel is an irreversible procedure. Bone and soft tissue can be regenerated through grafting procedures. Generally, the long‐term prognosis is better for a single implant than for a traditional bridge. Further, although the initial cost may be higher for a single implant, the long‐term cost is lower than for a traditional bridge. Also, replacing a single tooth will simplify possible future retention of prostheses such as FPDs, RPDs, and CDs.
Treatment factors for dental implant placement:
- Need for bone graft (?)
- Need for guided bone regeneration graft (?)
- Implant design Need for a custom abutment (?)
- Crown selection Interim partial denture (?)
- Implant maintenance
The site criteria for a simple implant:
- Bone width: ≥6mm
- Bone height: ≥6mm
- While the rule of 6 applies to the bone height as an absolute minimum requirement, it is highly recommended to have a 2mm zone of safety when dealing with the inferior alveolar nerve. So, if placing a 6mm implant in the posterior mandible, 8mm of bone height would be needed.
- Inter‐occlusal space: ≥6mm
If the bone criteria are not satisfied, then grafting or guided bone regeneration (GBR) may be necessary. The next decision is the choice of the implant system.
Implant system selection.
- Bone level
- Internal connection
- Platform switch
- Long‐term availability
- Wide array of restorative options
- Stock abutments (straight/ angled)
- UCLA abutments
- Multi‐unit abutments
- Ti bases
- Digital scan transfers
Regardless of the implant system selected, the implant site, or the various patient factors, the cautious dentist should always anticipate the worst and prepare for the need for bone grafting regardless of pre‐operative radiographic evidence.
The Single Crown
- The single implant‐retained crown replaces a missing tooth and can restore an unattractive or patient‐restricted smile, improve masticatory ability and slow down or retard bone loss.
- The other major advantage of the single dental implant is that it avoids the need for a three‐unit bridge.
- Another advantage of individually‐restored implants compared to bridges is that implants tend to retard continuing bone loss that often occurs at edentulous
The Edentulous Patient
- Treating edan entulopatientsent with severely resorbed ridges, flat ridges,s or, in the case of an upper denture, a shallow palatal vault, is a challenge to generadentistsst.
- Edentulous patients with these conditions have difficulty achieving a stable, retentive denture without resorting to retentive aids such as denture fixatives.
These are some of the patient complaints and dissatisfactions with complete dentures:
- Poor denture stability
- Lack of retention
- Diminished masticatory forces
- Pain due to impinging nerve eon severely resorbed mandible
- Speech impairment
- Impaired taste and thermal sensitivity with upper dentures oralral malodor
There are two basic choices for the “terminal dentition” or the edentulous patient. The first option is the implant over‐denture. The second option is the fixed implant bridge(s).
- The implant over‐denture is implant and tissue‐supported prosthesis.
- Generally, two to four implants are placed per arch to stabilize the denture.
- Specific abutments are placed on the implants and corresponding attachments are processed into the denture to create a “snapping‐in” of the denture.
- The patient should remove the appliance to clean daily.
- The patient is instructed to not sleep with the appliance.
- Recommended scheduled maintenance includes implant and prosthesis cleaning at 6‐month intervals, replacing denture attachments every six months–to one year, and relining the appliance every two to five years.
- Abutments may need to be replaced after five years due to wear although wear patterns can be variable due to patient factors.
Fixed Implant Bridge(S)
- Fixed implant bridges are completely implant‐supported screw‐retained prostheses.
- Generally, four to six implants are used to support the prosthesis.
- Materials used include milled bars (chrome–cobalt or titanium) and processed acrylic or milled prosthesis (poly-methyl methacrylate) [PMMA] or zirconia).
- Increasingly, zirconia is becoming the material of choice for these prostheses due to its strength, durability, and biocompatibility.
- When zirconia is utilized, the prosthesis is fabricated much like the traditional FPD, potentially allowing for better cleanability.
- Patients are educated in the use of water flosser devices as well as floss threaders.
- Regularlyar scheduled maintenance for fixed implant bridges include implant and prosthesis cleaning every six months, and appliance removal every one to two years with possible screw replacement.
- Regardless of the stabilization/retention method adopted, implant‐supported dentures successfully address, if not eliminate, most if not all the patient issues with CDs.
- With implant‐retained dentures, such problems as denture slipping, poor stability, impaired masticatory performance, ance and masticatory pain become things of the past for the edentulous patient.
When discussing the treatment plan, communicate with your dentist attentively because the dentist will explain all details and alternatives in concern with your wants and clinical situations.