Comprehensive Report on Oral Health: Microbes and Diseases

This report provides a comprehensive overview of oral health, beginning with an introduction to microorganisms and their classification, including bacteria, viruses, fungi, archaea, and protozoa. It delves into the oral microflora, detailing the various microbial habitats within the oral cavity and their roles in health and disease. The report explains the acquisition of oral flora, the process of dental plaque and calculus formation, and the factors that affect microbial growth. Furthermore, it explores the etiology of dental caries and gingivitis, discussing the mechanisms behind these common oral diseases. The report highlights the importance of understanding oral microbiology for maintaining overall health and preventing oral diseases.

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oRAL hEALTH
DECEMBER 26, 2019

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Contents
Introduction...........................................................................................................................................2
Microbial classification.....................................................................................................................3
Microbes in oral cavity......................................................................................................................3
Oral microflora in health and diseases...............................................................................................3
Acquisition of oral flora....................................................................................................................3
Dental plaque.....................................................................................................................................3
Calculus formation............................................................................................................................3
Factors affect microbial growth.........................................................................................................3
Etiology of dental caries and gingivitis..............................................................................................3
Conclusion.............................................................................................................................................2
References.............................................................................................................................................2

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Introduction
A microorganism is also known as microbe is an organism which can be only viewed
under the microscope. Microorganisms found almost everywhere even inside the human
body. There are different types of microorganism such as bacteria, viruses, fungi, archaea,
and protozoa (Biogeochemistry, 2018). Most of the microorganism is not harmful to human,
planta, and animals. In fact, humans in different processes like aiding decomposition, decay,
and digestion. There are trillions of micro-organisms present inside the human body. Each
individual has a separate and highly inconstant composition of microorganisms, though a
core set of microbes are common to all persons. Microbes are present in a different part of the
body such as skin, oral cavity, nasal cavity, gut, and reproductive system (Jin et al., 2016). In
this paper, the microbial classification, oral microflora in health and disorder, acquisition of
oral microflora, plaque biofilm formation, calculus formation, factors affecting microbial
growth, and the etiology of dental caries and gingivitis will be discussed.
Microbial classification
Bacteria are the unicellular organism and found in four major shapes rod shape,
spherical shape, spiral shape, and curved shape. Bacteria are categorized as gram-positive and
gram-positive. They are also categorized on the basis of their response to gaseous O2;
bacteria living in the presence of oxygen (aerobic), and bacteria living without O2
(anaerobic). On the basis of obtaining energy, these microbes are classified as heterotrophs or
autotrophs (Cowan, 2018).

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Viruses
Viruses are a non-cellular organism that has a nucleic acid core enclosed by a coat of
protein. Viruses are not able to reproduce outside the host cell and unable to metabolize on
their own. Viruses commonly infest prokaryotic and eukaryotic cells sourcing diseases.
Archaea
Archaea also are known as Archaebacteria are different from true bacteria in the
structure of cell walls and lack of peptidoglycans. On the basis of habitat, Archaeans can be
categorized as methanogens, halophiles, thermophiles, and psychrophiles (Cocola & Meloni,
2015).
Fungi

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Fungi are eukaryotic are multicellular and their cell wall is made up of chitin. They
acquire nutrients by absorbing the organic material from their surrounding environment.
Common fungi found in the mouth cavity is Candida albicans.
Protozoa
Protozoa are the unicellular eukaryotes that live in an aerobic environment. They have
a single nucleus, complex organelles, and attain food by absorption or ingestion by a
specialized structure. Protozoa found in the mouth cavity are Entamoeba gingivalis and
Trichomonas tenax (Anderson, Salm & Allen, 2016).
Microbes in the oral cavity
The oral cavity or mouth comprises numerous distinct microbial habitats for example
teeth, gingival sulcus, the gingiva, tongue, cheek, lips, gingival sulcus hard palate, and the
soft palate. the microbes found in the oral cavity of the human body are named as the oral
microflora, the oral microbiota or microbiome of the oral cavity (Lamont et al., 2019). The
oral microbiome comprises the species of Actinobacteria, numerous Bacteroidetes,
Chlamydiae, the Chloroflexi, Euryarchaeota, Firmicutes, Streptococcus, Fusobacteria,
Proteobacteria, Tenericute Spirochaetes, and, Synergistetes (Xu et al., 2015).
Oral microflora in health and diseases
The oral cavity of the human body is the main entry for microbes; therefore,
microorganisms that live in that part are very capable of distributing to dissimilar parts of the
human body. Pathogens that prompt in the oral cavity can be usually identified in blood
samples as they eliminate and transmit through the mucous membranes of the oral cavity and
periodontal pouches. Different Oral illnesses, for instance, dental caries and periodontal
disease are among the utmost prevalent problems globally, affecting closely all ages and
terrestrial populations (Borsanelli et al., 2018). The Collaboration and the balance of a range

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of oral microbes help the human body in contradiction of invasion of the unwanted
stimulation external. Though, the unevenness of microbial flora subsidizes diseases
associated with mouth oral and whole-body like dental caries, periodontal illnesses, diabetes,
circulatory diseases, etc. The oral microbiome has also been found to be associated with
Overweightness. As the inflammatory characteristic of obesity is extensively documented, the
composition of the salivary bacteria fluctuates in weighty women. species of bacteria could
serve as the biological indicators of the overweight condition. Oral bacteria might contribute
to the pathology that results in obesity. microbiomes of the mouth are strongly related to the
functioning of the immune system, thus are connected with human resistant system illnesses
like rheumatoid arthritis (RA), and make an alteration on multi-system illnesses performances
in the immune system (Zhou & Li, 2015).
Acquisition of oral flora
The existence of nutrients, epithelial debris, and excretions makes the mouth a
favorable environment for a great diversity of bacteria. The mouth offerings a sequence of

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different ecological circumstances with age, and this agrees with fluctuations in the structure
of the usual flora. The process starts with the establishment of habitat by pioneer bacterial
populations. In the oral cavity of infants, Streptococci are the pioneer microorganisms
(Rosenblatt, Steinberg, Mankuta & Zini, 2015). They fill the place of the novel environment
and adapt the habitat and the new populace develops. When no extra niche is obtainable for
the new population, a steady assemblage of microbial population is attained called a climax
community. At birth, the mouth of a full-term fetus is typically sterile, transient flora from the
birth canal might be developed. The mouth then speedily acquires microorganisms from
mother and from the environment. It comprises numerous species of Streptococcal and
Staphylococcal with Lactobacilli, Neisseria and Yeasts. Streptococcus salivarius is the utmost
common and forms the pioneer community with Staphylococcus albus. The baby comes into
interaction with an ever-increasing variety of microbes and some become established as a
portion of commensal flora. The outbreak of deciduous teeth delivers a new attachment
surface and turns Streptococcus sanguis and mutans as unvarying inhabitants of the human
oral cavity (Chawla et al., 2018).
Dental plaque
Dental plaque is mostly known as the primary cause of dental caries and other
different oral infections. Dental plaque found on the tooth and under the gums is the
colonization of different microbes that are bind together to form a biofilm. There are total six
different stages of plaque biofilm formation; in the first stage, an acquired pellicle layer is
formed which is composed of glycoproteins, phosphoproteins, and lipids (Murakami, Mealey,
Mariotti & Chapple, 2018). In the second stage, the colonizers like streptococcus sanguinis
form an initial attachment to the pellicle part through weak and van der Waals forces. In the
next phase, the attachment of bacteria results in an establishment which causes increased
complexity of dental plaque because of allogenic aspects, for example, consumption of

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oxygen within the plaque making anaerobic zones. This stage is called early maturation or
maturation 1. In the late maturation stage, the microbial diversity endures to upsurge, while
cell division rates reduce. The ecology of plaque microbe reaches to pseudo-state in which
there is a continues cell turnover. At this stage, a think3 dimensional layer of the dental
plaque is generated. The last stage of plaque formation is dispersion in which the biofilm
degrading enzyme enables the microbe to detach themselves from the plaque biofilm to
spread and multiply to other areas of the oral cavity (Volgenant et al., 2017).
Calculus formation
Calculus can be defined as the ectopic mineralized structure which consists of
mineralized bacterial plaque that build-up on the surface of individuals’ teeth and dental
prosthesis. The formation of calculus occurs in three different stages. Pellicle formation is the
first stage in which all the surface of the mouth cavity is coated with the pellicle following
the tooth eruption or the dental prophylaxis, acquired pellicle which is a thin, saliva-derived
layer covers the surface of a tooth (Keyes & Rams, 2016). The second stage is the initial
adhesion and attachment of the microbe. The bacteria are transferred to the tooth surface, and

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the reversible adhesion of the microbe happens, which is initiated by the connection between
the bacteria and the surface, by the long-range and short-range forces. A firm anchorage
between the bacteria and the surface is established by a specific connection. The next step is
colonization and the maturation of plaque. When the firmly linked microbes start multiplying
and the newly established bacterial clusters remain attached, the colonies of microbes or the
biofilm can build-up. Gram-positive coccoidal microorganisms are the primary settlers to
attach to the established enamel pellicle, and afterward, the filamentous microbes
progressively dominate the growing plaque biofilm (Balaji, Niazi & Dhanasekaran, 2019).
Factors affect microbial growth
A neutral pH is compulsory for the microbial growth in the mouth cavity. The
extremes level of pH is not appropriate for microbial growth. The pH of plaque is similarly
sensitive to the pH of saliva. After eating acidic food, the pH of the plaque also reduces to
around 5.0 because of the establishment of lactic acid through carbohydrate metabolism. This
reduction in pH gradually improves with time. The pH drop is lethal for the utmost plaque
bacteria. The mouth is kept at a comparatively steady oral temperature that is 35 to 36 °C.
This temperature range is vital for microbial growth (Dagli, Dagli, Darwish & Baroudi,
2016). It has been identified that periodontal pockets with an active illness have an increased

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temperature i.e. about 39 °C compared with healthy places. some Irritant chemicals are
present in the mouth, which have dissimilar effects in the temperature control of the oral
cavity. The host defense mechanism plays the main role in upholding the wellbeing of the
mouth cavity. The primary purpose of the immune system of the human mouth is to defend
the teeth, jaws, the gingiva and oral mucosa in contradiction of infection. These host defense
mechanisms vary in the diverse oral microenvironments or areas characterized by the oral
mucosa, mucosal saliva and the gingival crevice (Samaranayake & Matsubara, 2017).
Etiology of dental caries and gingivitis
The initial appearance of the caries development is a small cover of demineralized
teeth enamel at the surface, frequently unseen from sight in the grooves of human teeth or in
between two teeth. The destruction of teeth spreads into the softer, and sensitive areas of the
tooth underneath the enamel (Tanner et al., 2018). The deteriorated enamel then breakdowns
to create a cavity and the human tooth is increasingly destroyed. Dental caries is instigated by
the action of acids present on the surface of the enamel. The acid is formed when sugars
(mostly sucrose) in diets or drinks respond to bacteria existing in the dental biofilm on the
surface of the tooth. The acid formed to result in a loss of calcium and phosphate from the
enamel (Tonetti et al., 2017).

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Gingivitis another problem associated with oral health. it is produced by the
establishment of plaque which is a naturally up sticky film comprising bacteria on the surface
of teeth and gums. The microorganisms found in plaque generate toxins that can source gums
irritation and causes redness, swollen, puffy, and might even result in bleeding (Philipone &
Yoon, 2017). Toxins, or contagions, produced by the microorganisms in plaque in addition to
the body's favorable enzymes (worked in fighting contaminations), turn against the human
body and later start to disrupts the bone and the connective tissue that are essential for
holding the teeth in place (Chrysanthakopoulos, 2016).

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Conclusion
Microorganisms are found almost everywhere, even in the human. Some of them
cause health issues but mostly do not cause any harm. Microbes are classified as bacteria,
viruses, fungi, archaea, and protozoans. The microorganisms found in the human mouth are
called oral microflora. The microflora plays a key role in the health and associated diseases of
the mouth. The microflora fights against different other harmful microorganism. However, it
may also cause some diseases like obesity, dental caries, and gingivitis. The microbial flora is
acquired from the mother to fetus and the environment. Dental plaque is found on the teeth
and under gums and the most common cause of dental caries through six different steps.
Calculus is another damaging aspect of dental issues that are formed in three different stages;
pellicle formation, transfer of bacteria, and colonization and maturation. Factors affecting the
growth of bacteria in the mouth are temperature, pH, host defense system, diet, etc. both
dental caries and gingivitis are the result of unhealthy habits of humans and the infection
acquired from the environment.

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