Microbiology of Dental Caries: Unit 21

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the classification of dental caries based on the location of the lesion?

Bacterial caries

Pit or fissure caries (correct)

Acidic surface caries

Smooth surface caries

Which theory of dental caries dates back to the VII century BC?

Legend of the worm (correct)

Exogenous theories

Endogenous theories

Imbalance theory

What percentage of the population in Spain is affected by dental caries?

40% (correct)

30%

60%

50%

What are the consequences of dental caries mentioned in the text?

Aesthetic consequences Signup and view all the answers

Which type of caries is associated with an existing restoration?

Recurrent caries Signup and view all the answers

What is the main cause of tooth tissue destruction in dental caries?

Bacterial plaque Signup and view all the answers

Which theory of dental caries proposed that cavities are due to the acids produced by microorganisms from sugars?

Chemoparasitic theory of Miller Signup and view all the answers

According to the Keyes Scheme, which factor is involved in dental caries alongside tooth and oral microbiota?

Dietary habits Signup and view all the answers

Which bacteria is known for producing insoluble extracellular polysaccharides from sucrose, helping them adhere to tooth surfaces and bind more bacteria?

Streptococcus mutans Signup and view all the answers

What is the pH range below which demineralization of enamel starts, according to the text?

pH 5.3-5.7 Signup and view all the answers

Which factor can contribute to breaking the balance between demineralization and remineralization, leading to the appearance of caries?

Repeated and frequent intake of fermentable sugars Signup and view all the answers

Which type of decay is described as the most frequent in the initial lesion of caries affecting the enamel?

Pit and fissure decay Signup and view all the answers

Which bacterium has a low ability to colonize the tooth surface and is unimportant at the beginning of the lesion but becomes very important in the progression and dentin lesions?

Lactobacillus spp Signup and view all the answers

What does the text describe as a factor that can favor aciduric bacteria, such as S. mutans and lactobacilli, becoming predominant?

Frequent glucidic contributions leading to long acid periods Signup and view all the answers

Which theory suggested that bacterial proteolytic enzymes degrade organic matter, releasing chelating agents that dissolve tooth minerals?

Theory of proteolysis-chelation Signup and view all the answers

What is the most cariogenic sugar according to the text?

Sucrose Signup and view all the answers

Which factor is NOT involved in dental caries according to the Keyes Scheme?

Saliva pH level Signup and view all the answers

Which bacteria becomes predominant when pH drops below a certain range, as mentioned in the text?

Lactobacillus spp Signup and view all the answers

Which bacteria predominate in tissues such as root and dentine?

Lactobacillus Signup and view all the answers

What bacterium is isolated from the oral cavity of people without caries?

Streptococcus dentisani Signup and view all the answers

Which mechanism does fluoride utilize for the prevention of dental caries?

All of the above Signup and view all the answers

What is the main function of noncaloric sweeteners in preventing dental caries?

Not metabolized by bacteria Signup and view all the answers

What is the primary effect of polyols such as xylitol in preventing dental caries?

Having an antimicrobial effect Signup and view all the answers

What is the source of systemic fluoride intake?

Water and tablets Signup and view all the answers

Which factor does not contribute to the control of factors related to dental caries?

Increase in dietary sugars consumption Signup and view all the answers

What is a potential consequence of excessive fluoride intake?

Dental fluorosis Signup and view all the answers

What is the primary method for controlling bacterial plaque?

Mechanical removal of plaque (brushed). Signup and view all the answers

How can patients at high risk of dental caries be identified?

By exploring their level of hygiene. Signup and view all the answers

Which bacterium's growth is inhibited by bacteriocins?

Streptococcus mutans Signup and view all the answers

What is the main purpose of identifying patients at high risk of caries?

To provide targeted preventive measures. Signup and view all the answers

Study Notes

Classification of Dental Caries

Dental caries can be classified based on the location of the lesion as pit and fissure caries, smooth surface caries, and root caries.

Theories of Dental Caries

The theory of dental caries that dates back to the VII century BC suggests that cavities are due to the acids produced by microorganisms from sugars.
The Chelation theory proposes that bacterial proteolytic enzymes degrade organic matter, releasing chelating agents that dissolve tooth minerals.

Prevalence of Dental Caries

In Spain, approximately 80% of the population is affected by dental caries.

Consequences of Dental Caries

Consequences of dental caries include tooth tissue destruction, pain, and potentially, systemic infections.

Types of Caries

Recurrent caries is associated with an existing restoration.
Rampant caries is a type of decay that is described as the most frequent in the initial lesion of caries affecting the enamel.
Secondary caries occurs in the dentin.

Tooth Tissue Destruction

The main cause of tooth tissue destruction in dental caries is the acid produced by microorganisms from sugars.

Keyes Scheme

The Keyes Scheme involves three factors in dental caries: tooth, oral microbiota, and diet.

Bacteria and Dental Caries

Streptococcus mutans is known for producing insoluble extracellular polysaccharides from sucrose, helping them adhere to tooth surfaces and bind more bacteria.
Lactobacilli become predominant when pH drops below a certain range.
Actinomyces bacteria predominate in tissues such as root and dentine.
Streptococcus sanguis is isolated from the oral cavity of people without caries.

Factors Contributing to Dental Caries

Factors that can contribute to breaking the balance between demineralization and remineralization, leading to the appearance of caries, include diet, oral microbiota, and tooth characteristics.
A diet high in sugars and acids can favor aciduric bacteria, such as S.mutans and lactobacilli, becoming predominant.

pH and Demineralization

The pH range below which demineralization of enamel starts is 5.5.

Prevention of Dental Caries

Fluoride utilizes the mechanism of inhibition of acid production and inhibition of enzymatic activity to prevent dental caries.
Noncaloric sweeteners, such as xylitol, can prevent dental caries by reducing the amount of sugars available for fermentation by bacteria.
The primary effect of polyols, such as xylitol, in preventing dental caries is to reduce the production of acid by bacteria.
Systemic fluoride intake is primarily from community water fluoridation.

Control of Dental Caries

The primary method for controlling bacterial plaque is good oral hygiene practices, including regular brushing and flossing.
Patients at high risk of dental caries can be identified through a combination of clinical examination, radiographs, and evaluation of diet and oral hygiene habits.
The main purpose of identifying patients at high risk of caries is to provide targeted prevention and early intervention.

Bacteriocins

Bacteriocins can inhibit the growth of Streptococcus mutans.

Excessive Fluoride Intake

A potential consequence of excessive fluoride intake is dental fluorosis, which can cause white spots on the teeth.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the microbiology of dental caries in this quiz covering the definition, impact, and relevance of this chronic infectious disease. Learn about the bacteria in dental plaque and the effects on tooth tissues, including enamel, dentin, and cement.