The Diseases of the gums can broadly be classified into
- Gingivitis
- Periodontitis
GINGIVITIS is defined as an inflammation of the GINGIVA only.When the inflammation progresses to the other parts of the PERIODONTIUM it is termed as PERIODONTITIS.
Before we go into the nitty gritty world of gingivitis let,s understand the beginning of gum disease.
Many of you will be wondering that this is not possible as I take care of my teeth to the nth degree, but my friends don't forget about the bad bacteria lurking in your mouth!!!
As soon as we brush our teeth squeaky clean we remove any growth or covering on our tooth surfaces.
But this does not remain so as our teeth are constantly under a wet environment. The first step in plaque biofilm development is the
adsorption of host and bacterial molecules to the tooth surface.
Within minutes of tooth eruption or a cleaning, PELLICLE
formation begins, which can be defined as a thin coat of salivary
proteins. The pellicle acts like an adhesive
by sticking to the tooth surface and encouraging a conditioning film
of bacteria to attach to the pellicle. This
conditioning film directly influences the initial microbial
colonization, and continues to adsorb bacteria to the
tooth surface.This early composition of the biofilm is able to
withstand many of the frequent mechanisms of the oral cavity that
contribute to bacterial removal such as swallowing, nose blowing,
chewing, and salivary
fluid outflow. The early colonizers are also able to survive in the
high oxygen concentrations present in the
oral cavity, without having much protection from other bacteria .
Thus, this thin, initial biofilm is almost always
present on the tooth surface as it forms immediately after cleaning.
adsorption of host and bacterial molecules to the tooth surface.
Within minutes of tooth eruption or a cleaning, PELLICLE
formation begins, which can be defined as a thin coat of salivary
proteins. The pellicle acts like an adhesive
by sticking to the tooth surface and encouraging a conditioning film
of bacteria to attach to the pellicle. This
conditioning film directly influences the initial microbial
colonization, and continues to adsorb bacteria to the
tooth surface.This early composition of the biofilm is able to
withstand many of the frequent mechanisms of the oral cavity that
contribute to bacterial removal such as swallowing, nose blowing,
chewing, and salivary
fluid outflow. The early colonizers are also able to survive in the
high oxygen concentrations present in the
oral cavity, without having much protection from other bacteria .
Thus, this thin, initial biofilm is almost always
present on the tooth surface as it forms immediately after cleaning.
Passive Transport of Oral Bacteria to the Tooth Surface
Following pellicle formation, there is passive transport of oral
bacteria to the tooth surface, which involves a reversible adhesion
process. By using weak, long-range physicochemical interactions
between the pellicle coated tooth surface and the microbial cell
surface, an area of weak attraction is formed that encourages the
microbes to reverse their previous adhesion to the pellicle and come
off the tooth surface (hence the term "reversible adhesion"). This
reversible adhesion then leads to a much stronger, irreversible
attachment, as short-range interactions between specific molecules
on the bacterial cells and the complementary receptor proteins on
the pellicle surface occur. Because many oral microbial species
have multiple adhesion types on their cell surface, they can thus
participate in a plethora of interactions with both other microbes
and with the host surface molecules.
Co-Adhesion of later colonizers to already attached early colonizers
The co-adhesion of the later colonizers to the already
present biofilm continues to involve many specific
interactions between bacterial receptors and adhesions.
These interactions build up the biofilm to create a more
diverse environment, which includes the development of
unusual morphological structures like corn-cobs and
rosettes.
The many interactions between these diverse bacterial
species begin to create a number of synergistic and
antagonistic biochemical interactions. For example, bacterial
residing in food chains may help to contribute metabolically
with other bacteria if they are located physically close to one
another. Similarly, when obligate anaerobes and aerobes
are involved in co-adhesion, these interactions can ensure
the anaerobic bacteria’s survival in the oxygen-rich oral
cavity.
Multiplication of the Attached Microorganisms
Eventually, the bacterial cells continue to divide until a three-
dimensional mixed-culture biofilm forms that is spacially and
functionally organized. Polymer production causes the
development of the extracellular matrix, which consists of
soluble and insoluble glucans, fructans, and
heteropolymers. This matrix is one of the key structural
aspects of the plaque biofilm, much like that of other
biofilms. Biofilms such as this are very thick, consisting of
100-300 cell layers. The bacterial stratification is arranged
according to metabolism and aerotolerance, with the
number of gram-negative cocci, rods and filaments
increasing as more anaerobic bacteria appear. As the
biofilm thickens and becomes more mature, these anaerobic
bacteria can live deeper within the biofilm, to further protect
them from the oxygen-rich environment within the oral
cavity.This biofilm is now composed of a variety of bacteria
and is now known as DENTAL PLAQUE.
Plaque formation
At 24 hours the maturing dental plaque contains a wide variety of bacteria and it is possible to detect easily identifiable inter-species associations such as the well documented "corn-cob-configurations", although a wide variety of other inter-species associations will be present.
Further colonisation and growth of established bacteria takes place as the plaque matures to form a stable, climax, community. This pattern of development leading to a climax community has been termed "bacterial succession". The resulting community consists of individual microbes and microcolonies acting in complex consortia which can convey a range of beneficial properties. These include feeding synergies, improved antibiotic resistance and a host of cooperative mechanisms which are the subject of much current research.
Plaque response to environmental change
Although mature plaque has a degree of stability conferred by inter-species cooperativity, physical and metabolic associations and its actual physical density it does respond to environmental change albeit slowly. The best recorded response is that due to changes in diet.
High protein diet
Plaque formed on the teeth of individuals with a low carbohydrate, high protein diet, contains fewer acidogenic-aciduric organisms. The pH gradient will be different and the overall pH of the plaque alkaline because of the ammonia produced as a by-product of amino acid breakdown. The higher pH of the plaque will itself inhibit acidogenesis and favour Gram negative organisms which will be present in greater numbers. The proteolytic nature of the plaque will result in the presence of particular peptides such as putrescene and cadaverine which have a characteristic offensive odour.
High carbohydrate diet
If this same individual, previously on a high protein, low carbohydrate diet switched to a low protein, high carbohydrate diet the formed plaque would slowly adjust its microbiological composition. The resting pH of the plaque would reduce to somewhere between pH 6.3 to 6.8 (figures are approximate) as a result of the production of organic acid by-products from the fermentation of carbohydrate. This lower, more acid, pH favours aciduric organisms such as streptococci and lactobacilli and the proportion of these would greatly increase. This would be coupled with a reduction in the numbers of Gram negative anaerobic rods which do not flourish under these conditions.
High sucrose
If the change in diet included an increase in sucrose consumption then the plaque matrix would contain large amounts of extracellular polysaccharides of both the fructan and glucan variety.
Frequent carbohydrate
If the diet included frequent intake of carbohydrate eg snacking on confectionary then the plaque would contain significantly increased numbers of highly aciduric organisms such as Streptococcus mutans and lactobacilli.
Time scale
These changes would occur over a time period of a few days even if the plaque had not been removed from the teeth when the diet changed. It follows that individuals on such extremes of diet produce such characteristic plaque even though they practice normal oral hygiene.