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 Addisons 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.
Pagets
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.
