Lecture 1 (Part I - Caries Etiology, Pathogenesis and modifying factors of Dental Caries) Flashcards
an infectious microbiological disease of the teeth that results in localized dissolution and destruction of calcified tissues.
Dental Caries (Then)
Dental caries is a biofilm-mediated, sugar-driven, multifactorial, dynamic disease that results in the phasic demineralization and remineralization of dental hard tissues.
Dental Caries (Now)
The balance between pathological and protective factors influences the initiation and progression of caries.
Dental Caries (Now)
Dental caries is a ____, ____, ____, ____ that results in the phasic demineralization and remineralization of dental hard tissues.
- biofilm-mediated
- sugar-driven
- multifactorial
- dynamic disease
It is a biofilm-mediated, sugar-driven, multifactorial, dynamic disease that results in the phasic demineralization and remineralization of dental hard tissues.
Dental Caries
is the name of the disease.
Dental Caries
is the symptom of the disease.
The caries lesion or cavitation
The management at the ____ is inadequate and would lead only to recurrence and ultimately to tooth loss.
Lesion Level
Treat the ____ (person/individual level), not the ____ which is just a symptom of the disease.
Treat the disease (person/individual level), not the lesion which is just a symptom of the disease.
Treat the disease (in what level: ____), not the lesion which is just a symptom of the disease.
person/individual level
a complex disease.
Caries
____ and ____ should be done at the tooth, person and community levels.
Prevention and management
Prevention and management should be done at the tooth, ____ and____ levels.
person and community levels.
FACTORS INVOLVED IN THE CAUSATION OF DENTAL CARIES:
- Oral microorganism in the biofilm
- Host (tooth, oral fluids, genes)
- Substate (cariogenicity of consumed
carbohydrates, oral clearance, eating frequency and
food detergency) - Significant length of time for the 3 factors to interact
- tooth
- oral fluids
- genes
Host
- Cariogenicity of consumed
- carbohydrates
- oral clearance
- eating frequency
- food detergency
Substrate
Pathogenesis of dental caries involves disturbances in two types of ____/____ that exists in the oral cavity
homeostasis/ physiological equilibrium
Pathogenesis of dental caries involves disturbances in two types of homeostasis/ physiological equilibrium that exists in the oral cavity:
- Disruption of microbial homeostasis in the ‘biofilm’
- Disruption of the mineral homeostasis between the tooth and the oral fluid
Disruption of microbial homeostasis in the ____.
biofilm
Disruption of the mineral homeostasis between the ____ and ____.
tooth and the oral fluid
A ____ is defined as the population or community of bacteria living in organized structures at an interface between a solid and liquid
biofilm
Age
Tooth
Exposure to fluoride
Tooth
Tooth/surface morphology
Tooth
Root surface exposure
Tooth
Quantity/Flow rate
Oral fluid/saliva
Quality/Buffering capacity
Oral fluid/saliva
common clinical sites of caries initiation
Tooth
Base of pits and fissures
Tooth
Root Surfaces
Tooth
Smooth enamel surfaces that shelter plaque
Tooth
areas cervical to the contact areas
Tooth
distal surface of most posterior tooth
Tooth
areas cervical to the heights of contour on the facial and lingual
Tooth
Chronically low salivary flow rate is one of the strongest indicators of increased caries risk
Host Salivary Factors
Chronically ____ is one of the strongest indicators of increased caries risk
low salivary flow rate
SALIVA: NATURE’S ANTICARIES AGENT
- Bacterial Clearance
- Buffers
- Remineralization
flushes planktonic bacteria
Bacterial Clearance
Bacterial clearance flushes ____ bacteria
planktonic
Bacterial Clearance direct ____ activity
Direct antibacterial activity
Bacterial Clearance
Bicarbonate ions
Buffers
Sialin and urea hydrolyzed to form ammonia causing pH to rise
Buffers
____ and ____ hydrolyzed to form ammonia causing pH to rise
Sialin and urea
Sialin and urea hydrolyzed to form ammonia causing
pH to rise
supersaturated with calcium and phosphate ions
Remineralization
Researchers initially believed that
____ were less important in determining caries risk than were environmental influences, such as microbial and dietary factors
genetic factors
Clearance rate
Substrate
An individual’s ____ can potentially prevent the existence of certain beneficial bacteria or allow pathogenic species to reside and contribute to its unique microbiome.
genotype
Eating frequency
Substrate
Food detergency
Substrate
Cariogenicity of consumed carbohydrates. Sucrose
is more cariogenic than glucose and fructose.
Substrate
____ is more cariogenic than glucose and fructose.
Sucrose
Why is sucrose the most cariogenic among all the carbohydrates?
- it is a relatively small molecule
- can easily enter the plaque
- sucrose for energy production and the process produces acid
- Sucrose is also used by bacteria to produce extracellular polysaccharide called dextrans
- It will help plaque stick to the tooth surface, making it more difficult to remove
Bacteria like to use ____ for energy production and the process produces ____.
Bacteria like to use sucrose for energy production and the process produces acid
is also used by bacteria to produce extracellular polysaccharide called dextrans.
Sucrose
Sucrose is also used by bacteria to produce extracellular polysaccharide called ____.
dextrans
ORAL BACTERIA IN BIOFILM:
- Microbial load
- Plaque composition
- Plaque acidogenicity
- Plaque aciduricity
- Presence of fluoride in plaque
Properties of bacteria that contribute to Microbial Pathogenicity and Cariogenicity:
- Acidogenicity
- Acidurity
- Adherence
ability to produce acid from a fermentable substrate
Acidogenicity
ability to survive in an acidic environment
Acidurity
ability to attach to tooth surface
Adherence
A gelatinous (soft, translucent and tenaciously adhering) mass of bacteria adhering to the tooth surface.
Dental Plaque (Then)
An aggregate of microorganisms in which cells adhere to each other and/or to a solid substrate exposed to an aqueous surface.
Biofilm (Now)
The bulk of the volume (~90%) of ____ is comprised of a gel-like matrix of extracellular polysaccharides produced by oral bacteria.
dental plaque biofilm
The gelatinous nature of the plaque limits outward diffusion of metabolic products and thus serves to prolong the retention of acids.
Biofilm (Now)
produces lactic acid from sucrose
Acidogenic
can live in pH as low as 4.2
Aciduric
Acidogenic produces lactic acid from
Sucrose
Aciduric - can live in pH as low as
4.2
is the collective term for all the serotypes
mutans streptococci
can produce great amounts of acids
Mutant Streptococci and Lactobacilli
are tolerant of acidic environments
Mutant Streptococci and Lactobacilli
are vigorously stimulated by sucrose, and appear to be the primary organisms associated with caries in humans.
Mutant Streptococci and Lactobacilli
Streptococcus mutans
Humans
Streptococcus sobrinus
Humans
Streptococcus rattus
Rats
Streptococcus cricetus
Hamsters
Streptococcus ferus
Wild rats
Streptococcus macacae
Primates
Streptococcus downei
Primates
Mutans Streptococci
Enamel Caries
MS and Lactobacilli species
Dentin Caries
Actinomycetes species e.g. Actinomycetes
viscosus)
Root Caries
S mutans is only one of more than 500 species found in the dental plaque
TRUE OR FALSE
TRUE
S mutans is detectable in 10 to 20% of people who have severe caries
TRUE OR FALSE
FALSE - S mutans is not detectable in 10 to 20% of people who have severe caries
was an American dentist and the first oral microbiologist
Willoughby Dayton Miller (1853-1907)
EVOLVING THEORIES ON ETIOLOGY OF DENTAL CARIES:
- Miller’s Chemoparasitic Theory
- Nonspecific Plaque Hypothesis (NSPH)
- Specific Plaque Hypothesis (SPH)
all plaque are pathogenic
Nonspecific plaque hypothesis
plaque is pathogenic only if associated with clinical disease.
Specific plaque hypothesis
The goal of therapy is to suppress the cariogenic plaques and to replace them with pathogen-free plaques - Walter Loesche
Specific plaque hypothesis
According to this hypothesis, a certain change in the environment of the residential plaque flora provides pathogenicity to specific species that produce the disease only at specific sites.
The Ecological Plaque Hypothesis (1991)
First to colonize biofilm are
- S. oralis
- S mitis
- S. sanguis
Only ___% is S. mutans
1%
30-60 minutes after acid attack, buffers in saliva can increase the ____
pH
there is equilibrium of minerals between tooth surface and oral fluids
neutral pH
When pH goes ____ 5.5, minerals (HA) at the tooth surface are dissolved to maintain equilibrium of the oral fluid
down below
When pH ____, the oral fluids become supersaturated with phosphates and calcium.
goes up
At pH ____ in the presence of Fluoride, there is reprecipitation of hydrofluorapatite
Less than 4.5