What are the basic concepts and techniques of dental implants?

This summary is based on the article published in Dental Clinics of North America: Basic Concepts and Techniques of Dental Implants (April 2015)

Jonathan M. Tagliareni, DDS; Earl Clarkson, DDS

Context

• Dental implants provide a predictable, effective, and reliable means for tooth replacements.
• Additionally, dental implants provide completely edentulous and partial edentulous patients the function and esthetics they had with natural dentition. It enables patients to regain normal masticatory function, esthetics, speech, smile, and deglutition.
• In patients with orofacial pain, it may resolve painful symptoms as well as improve facial esthetics and appearance.

Key Points

Biological and Functional Considerations

• Osseointegration is the primary goal of implant placement. Osseoeintegration can be defined as the direct structural and functional connection between organized, living bone and the surface of a load-bearing implant without intervening soft tissue between the implant and bone.¹
• Clinically, osseoeintegration can be defined as the asymptomatic rigid fixation of an implant in bone with the ability to withstand occlusal forces.²
• Rigid fixation is a clinical term that implies no observable movement of the implant when a force of 1 to 500 g is applied.
• Improved imaging techniques help aid in diagnosis; a varied availability of implant geometries, surfaces, and refined surgical techniques has made it possible for most healthy patients to receive implants.
• Numerous materials are available to aid in bone regeneration in the maxillofacial region, including bone substitute composite grafts and autogenous bone.
• Osteotomies should be completed under copious irrigation using sharp osteotomy drills at high torque and slow speed. It is critical to maintain bone temperatures under 47⁰C.
• The material of choice for implants needs to be biocompatible with bone and biologically inert. Titanium is an optimal material that encompasses both of these required qualities.
• Volume and quality of bone that contacts the implant determine its initial stability which must be maintained in order for bone to form at the implant surface and for successful osseoeintegration.
• A single-stage surgery requires adequate primary stability and can be loaded immediately. A 2-staged approach requires submerging the implant when initial stability is less than adequate. A surgical uncovering and placement of healing abutment is required in 3 to 4 months.

Soft Tissue

• Soft tissue thickness should be assessed prior to surgery, noting that soft tissue thickness affects the vertical edentulous space.
• The minimum vertical space needed for a cemented crown is 9 mm; however, the tissue thickness is as much as 3 mm in the posterior mandible, affecting the depth of implant placement.

Biomechanical Considerations

• The load-bearing capacity of the integrated implant has to be greater than the anticipated load during function³ to avoid biological and mechanical failures
• Several factors, including number and size of implants, arrangement and angulation, and volume and quality of the bone–implant interface, determine the load-bearing capacity of the implants.

Medical History and Risk Assessment

• When discussing surgical implant therapy, there are only few medical absolute contraindications, including patients who are acutely ill and those with uncontrolled metabolic disease.⁴
• Relative contraindications include bone metabolism disorders and issues with patient healing ability. These conditions may include immunocompromised patients, diabetes, osteoporosis, bisphosphonate usage, and medical treatment, including chemotherapy and irradiation of the head and neck.⁵

Oral Examination

The clinician should:

• Examine existing teeth and prosthetics, periodontal health, oral hygiene, vestibular depths, jaw relationships, interarch spaces, and maximum incisal opening.
• Examine for para-functional habits, including clenching and grinding, observing for wear facets on the occlusal surfaces.
• Visualize and palpate height and width of edentulous ridges.
• Scrutinize the soft tissue meticulously, documenting clinical biotype and zones of keratinization, areas of redundancy, mobility, and possible pathology.

Radiographic Examination

More comprehensive treatment planning can be completed using complex cross-sectional imaging, including CT and cone-beam CT.

• Phase 1: pre-surgical implant imaging, involves past radiographs and new radiologic examinations to assist in finalizing a comprehensive treatment plan and it allows clinicians to determine the quality and quantity of bone available, vital structure identification, evaluation of implant sites, and presence or absence of pathology.
• Phase 2: the surgical and intraoperative imaging phase, is used to assist the surgical intervention of patients.
• Phase 3: post-prosthetic implant imaging, gives access to maintenance plans, information regarding function, and integration of the implant.

Quantifying measurements from radiographs needs to account for magnification. The magnification factor can be calculated at the given site by dividing the actual diameter of the object by the diameter measured on the on the radiographic image.

Measuring vertical restorative space or crown height space is paramount in the successful placement and restoration of endosseous implants.

References

List of references (PDF)