Glossary of Terms

This page includes a collection of frequently occurring terms, used in this web site. Most of these terms are dental or medical in nature and are just briefly explained in ‘plain English’.

Abutment – usually some metal or ceramic piece that is machined and attached to the implant fixture. There are several types of abutments; each designed for a specific task. Some are designed to heal or shape tissues after the uncovery procedure (see below), and others are designed to carry the crowns for the implants.

Adrenal Insufficiency – a condition where the medulla and/or the cortex of the adrenal gland is compromised in its production of epinephrine, norepinephrine, cortisol, corticosterone and aldosterone. Cortical insufficiency produces a clinical condition called Addison’s Disease, characterized by extreme weakness, low blood pressure and pigmentation of the skin. If severe enough, elective surgery such as implant surgery may not be indicated.

Anemia – indicates a quantitative deficiency of hemoglobin and usually also a corresponding decrease of red blood cells. There are several classifications of anemia, however they all have a decreased healing potential in common. Again, depending on the severity of the condition, elective surgery such as implant surgery may not be indicated.

Aortitis – an inflammation of the aorta or other arteries. The acute variety may arise from bacterial infections and carry along complications such as thrombosis, rupture with hemorrhage and aneurysms. The chronic variety may often be seen in tuberculosis and syphilis. This, in turn, may lead to necrotizing and fibrosing inflammation, which may compromise the structural integrity of blood vessels.

Aortic Aneurysm – a localized, abnormal and persistent dilation of a section of the aorta. This usually results from a weakness in the vessel wall. If severe enough, rupture of the aorta with severe hemorrhage is a potential hazard.

Arteriosclerosis – literally means hardening of the arteries and is often used synonymously with atherosclerosis. There is only a histologic difference between the two, depending on which layer of the artery wall is involved. Arteriosclerosis itself is characterized by thickening of the artery wall, and simultaneous decrease of the inside diameter (lumen) of the artery, thus compromising blood flow and increasing the blood pressure.

Autogenous Bone – bone harvested for grafting purposes from a donor site within the same individual. It is considered the Gold Standard to which all other bone graft materials are compared.

Bone Morphogenic Proteins (BMPs) – endogenous family of proteins belonging to the Growth Factor group. BMPs were isolated and later produced via recombinant gene technology in order to find a bone graft substitute closely matching, if not improving the qualities of autogenous bone. Several variations (fourteen) of BMPs were isolated so far; two of which may find great potential in future bone grafting procedures.

Bone Grafting – the process of augmenting a bone deficient site or area with more bone. The bone graft can be autogenous, allogenic, xenogenic or alloplastic in nature (see Bone Grafting). Recently Growth Factors (above) have also entered the scene for potential graft material.

Bridge – a fixed prosthesis designed to replace missing teeth. A conventional bridge uses the teeth adjacent to the edentulous (toothless) site as anchorage to suspend the missing tooth or teeth. All teeth in a bridge are usually splinted together. An implant bridge may sometimes not suspend a missing tooth, but rather splint all teeth, which are attached to implants together, in order to improve the biomechanical loading characteristics of the implant fixtures.

CT Scan – an x-ray machine that can deliver sectional x-ray pictures in small intervals in three different dimensions (panoramic, cross-sectional, and axial). Three-dimensional pictures can also be generated from the CT-Scan data. In addition to that, CT-Scanners and their software also have the ability to measure bone and tissue density, based on Houndsfield units.

Dental Implant – a metal device placed into or on top of the jaw bone to provide support and/or retention for a dental restoration or prosthesis (see the Types of Dental Implants section for more details).

Denture – a removable prosthesis or appliance designed to replace all the missing teeth in the upper as well as the lower jaw. A denture is only supported by the soft tissues in the mouth and, thus, does not offer great stability and/or chewing power.

Diabetes – AKA Diabetes Mellitus is a disease caused by an absolute or relative deficiency of the hormone insulin. This, in turn, gives rise to a disturbance in carbohydrate metabolism, the inability to store glycogen in the liver, excessive glucose in the blood and urine, acidosis and disturbance in protein metabolism. The latter can be a factor responsible for poor wound healing.

Foramen – a hole in a bony structure, through which nerves, and blood vessels either enter or exit. Foramina (pl.) are used in surgery as anatomical landmarks.

Fibrous Dysplasia – a developmental defect mainly involving bone. Symptoms usually include pain, disability and deformity of limbs, usually beginning in early childhood. The abnormal bone formation may reduce the success rates for dental implants.

Healing Abutment or Collar – an abutment (see above) placed on implants after the uncovery procedure (see below). Its purpose is to create an emergence profile in the gum tissues for the future implant crown. Sometimes the healing abutments are replaced with temporary crowns instead.

Hemophilia (Factor VIII, IX, X, XII) – an inherited abnormality of the blood appearing only in the male population. The coagulation time of the blood is prolonged, despite the fact that bleeding time, prothrombin time, platelet count and tourniquet tests are normal. In the classical hemophilia (caused by a deficiency in Factor VIII) severe and prolonged hemorrhages can follow trivial injuries. This can pose a management problem during elective-type surgeries.

Histiocytosis X – a condition where diffuse hyperplasia of certain tissues involves organs such as spleen, liver, lungs, bone marrow and lymph nodes. This condition is more frequent in infants and little children.

Hydroxylapatite – with respect to dental implants, a coating bonded to the titanium surface of an implant in order to enhance its ability to fuse to bone faster.

Hypothyroidism – a condition where insufficient function of the thyroid gland produces a general retardation of physical growth and depressed metabolism.

Mallet – a surgical instrument in the shape of a double-ended blunt hammer, used to drive other surgical tools or devices into bone.

Membrane – in the field of dental implant surgery it is referred to a little sheet made up of different materials (GoreTex, Collagen etc.) and designed to protect a grafted bone site from influx of soft tissue cells. Soft tissue cells would compromise bone healing, since they proliferate at a faster rate than bone cells.

Oral Implantology – a specialized field of dentistry, dealing with the placement and restoration of dental implants.

Osseointegration – the fusion of the surface of a dental implant to the surrounding bone, so that it is secured tightly in the bone and ready to be used as an anchor for a tooth or prosthesis.

Overdenture – much like a conventional denture, except for some attachment mechanism built in, giving it better retention. Overdentures can be made for implants as well as for some remaining natural teeth.

Paget’s Disease – a condition where the existing bone is resorbed with simultaneous overgrowth of new, poorly calcified, irregular bone. This type of bone may not have enough density for proper integration of dental implants.

Para-nasal Sinuses – two air filled bony sacks or cavities on each side of the nose. Phylogenetically a remnant from our marine origin, the para-nasal sinuses grow larger in volume as we get older (they undergo pneumatization). Each sinus has a direct communication with the nose via an opening called the ostium.

Peri-Implantitis – an inflammatory condition around dental implants, often associated with some bone loss. Peri-implantitis can be compared to periodontitis in natural teeth.

Periodontics – a specialized field of dentistry, mainly dealing with the repair and maintenance of the supporting tissues around teeth. Periodontics often also includes minor oral surgical procedures, as well as placement of dental implants.

Prosthesis – with respect to dentistry, any type of appliance that replaces actual missing teeth. This can range from a bridge, replacing a single missing tooth to a removable appliance, such as a denture, replacing all missing teeth.

Removable Partial Denture – a removable appliance or prosthesis, which typically attaches to selected teeth in the mouth and replaces usually several missing teeth.

Sarcoidosis – a systemic, granulomatous disease involving several organs as well as bone marrow. Heavy involvement of the heart and lung tissues as well as the immune system may make a patient with sarcoidosis not an ideal candidate for elective surgeries.

Temporary Prosthesis or Crown – a prosthesis (crown, bridge, denture, etc.) used for temporary purposes until the final prosthesis is ready to be used.

Titanium – although by some considered an exotic metal it is actually on of the most abundant elements on earth. However, it took scientific advances of modern metallurgy to turn this black sand into useful metal. Commercially pure titanium currently comes in four different grades (1-4), grade four being the finest. Most dental implants are either machined out of commercially pure titanium or an alloy thereof. The most frequently used alloy is Ti Al6V4. This alloy improves the fracture resistance of titanium and does not compromise the osseointegration (see above) into bone.

Tuberculosis – caused by Mycobacterium tuberculosis, stimulating specific tissue reactions resulting in necrosis. The lung is the organ most frequently affected, but other organs are also commonly involved. If the respiratory system is severely compromised, blood oxygen levels may drop and make surgical management more complicated.

Uncovery – a small surgical procedure done, in order to expose the head of the implant and connect a healing abutment or temporary prosthesis (see above). This is usually done after the implant has matured in the bone for several months. Some implants are designed to remain exposed in the mouth right after they are placed, abolishing an uncovery procedure all together.

Vasoconstrictor – a chemical substance that triggers constriction of blood vessels (usually arterioles), limiting blood flow through these vessels.

As with the Frequently Asked Questions section, I will frequently update the Glossary depending on the questions I receive. Please feel free to e-mail me any questions you might have.