A screw made of titanium that is screwed into the jawbone using specialised and specified techniques to resemble a tooth root.Diagnostic wax up: Procedure in which the teeth are created to match the planned restoration and used in planning and also for construction of a radiographic and surgical guide.Digital workflow: A workflow that uses digital technology to convert analogue structures into a digital format.External connection: The connection that protrudes on top of the implant fixture platform and connects the prosthesis to the fixture.Fixed prosthesis: A prosthesis that is fixed to the implant fixture which the patient cannot remove for cleaning.Fixation screws and tacks: Used to stabilise membranes or block grafts to the underlying bone.Fixture: Endosteal dental implant.Guide drill: The first drill used to open the cortical bone at the implant site during implant surgery.Guided bone regeneration: Technique used to selectively allow bone cells to populate the defect.Healing abutment/cap: Used after the first- or second-stage surgery to connect the implant fixture to the oral cavity.Implant stability: Clinical evaluation of the implant assessing its degree of stability.Implant substructure: The metal framework onto which the crown or prosthesis is connected.Impression coping: A device used to register the position of the dental implant or abutment.Immediate loading: The prosthesis is placed underload at the same time as implant fixture placement.Internal connection: The connection which sits inside the body of the implant fixture and links the implant fixture to the prosthesis. It comes in different configurations.Peri-implant diseases: Include peri-implant mucositis where there is reversible inflammation of the gingival tissues and peri-implantitis where there is irreversible loss of bone with inflammation.Prosthetic screw: Screw used to connect the prosthesis to the abutment.Primary stability: Mechanical stability achieved when the implant fixture is placed. Also knows as the initial stability.Provisional restoration: Temporary restoration placed whilst the tissues are healing.Radiographic marker: A radio-opaque material incorporated into the radiographic guide to show the position.Radiographic stent/guide: Used to direct the position of the tooth in relation to the underlying bone. Worn by the patient when having the radiograph or CT scan.Regeneration: Technique used to reconstitute tissues lost through disease.Surgical guide/template: Used during the surgical implant placement to guide the placement of the implant fixture to be placed in the correct restoratively driven position and angulation.Torque driver: Instrument used to apply the correct level of tightening force (torque) to the screws.Two-stage surgery: When the implant fixture is covered over by the soft tissue and a minor procedure is undertaken to uncover the fixture.
1 History of Dental Implants
The concept of dental implants dates as far back as 2000 BC when carved bamboo pegs were originally used to replace missing teeth. A dental implant is a prosthetic device made of alloplastic material implanted either into the oral tissues beneath the mucosal and/or the periosteal layer and/or within the bone to provide retention and support for a fixed or removable prosthesis. When inserted into the bone, the implants are called endo-osseous implants.
Around 3000 years ago, Egyptians used metal pegs to replace teeth, and it was not until the 1930s the concept of modern implantology came into existence with progressive development of methods used to replace missing teeth (Table 1.1). The materials from which dental implants are made should be biocompatible, corrosion resistant, and encourage bone ingrowth and biofunctionality.
Table 1.1 Progressive Development of Methods used for Tooth Replacement.
| 500–2500 BC | 300–600 AD | 800 AD | 1500–1800s | 1809 | 1913 |
|---|---|---|---|---|---|
| – Egyptians tried splinting teeth using gold ligature wires – Eustracians used customised soldered gold bands from animals and oxen bone | – Phoenicians used Ivory to carve teeth used as bridge replacements – Mayans introduced the concept of implants when they tried to use ‘Pieces of Shells’ as implants to replace mandibular teeth; Radiographs taken in the 1970s of such mandibles show compact bone formation around the implants (bone similar to that around blade implants) | Hondurans used a stone implant and placed this in the mandible | Europeans used cadaver teeth for allotransplantation | J Maggiolo inserted a gold implant tube into a fresh extraction socket and after healing a crown was added; other materials used were silver capsules, corrugated porcelain | Dr Greenfield placed a ‘24-gauge hollow latticed cylinder of iridio-platinum soldered with 24-karat gold’ as an artificial root to ‘fit exactly the circular incision made for it in the jawbone of the patient’ |
During 1939–60s the concept of the ‘in the bone’ (endosteal) implant arose with the first cylindrical endo-osseous solid screw implant with threads both internally and externally with a smooth gingival collar and healing cap being placed. Following this during the 1940s, a spiral stainless steel post type endosseous implant with a design that allowed bone to grow into the implant emerged and Dahl in Germany, around the same time, introduced the concept of the subperiosteal implant with mucosal inserts (Figure 1.1). This implant was made of cobalt-chromium molybedenum with a direct impression of the struts on the ridge crest taken to construct the denture. Throughout the 1940s–50s variations on the original Dahl design emerged in an attempt to make the provision of implants simpler and included the use of vitallium implants in 1948, the Linkow endo-osseous blade vent implant in 1966 with different designs for the maxilla and mandible (Figure 1.2), the ramus frame implant in 1970, made of stainless steel (Figure 1.3) and mandibular transossteal implant which engaged the lower border of the mandible with inserts projecting into the mouth to support a prosthesis (Figure 1.4). The ramus frame and tranossteal implants were predominantly designed for patients with atrophic mandibles who had difficulties wearing dentures and were used to aide denture retention to improve function.
Figure 1.1 Subperiosteal implants in the mouth.
Figure 1.2 Blade vent implants.
Figure 1.3 Ramus implants.
Figure 1.4 Mandibular tranossteal implant.
The key challenge with these older implant systems was biocompatibility, the lack of fusion to the jawbone resulting in recurring infections after a period of time and the complex surgical techniques needed to insert the implants leading to limited use aimed at specific
