Cariology Flashcards
What is the definition of caries?
Demineralization and loss of substance of the hard tissues of the teeth, leading to continued destruction of enamel and dentine, and cavitation of the tooth.
What 3 factors are involved in caries formation?
Host and saliva, diet, and microflora
What are the 5 risk factors in caries development?
- Pathogenic plaque bacteria
- Poor oral hygiene
- Reduced salivary flow/ Systemic conditions
- Bad dietary habits
- Anatomic variations: hard to clean areas
What are the 5 protective factors from caries development?
- Non-pathogenic plaque bacteria
- Good oral hygiene
- Adequate salivary flow
- Good dietary habits
- Fluoride, xylitol
What are the 3 functions of enamel?
- Provides hard, durable surface for teeth
- Forms a protective cap for the dentin and pulp
- Gives shape of teeth
What are the 2 basic structural units of enamel?
- Cylindrical enamel rods
2. Surrounding interrod enamel
What are the 2 protective mechanisms of enamel?
- Tightly compressed crystals- little or no space for acid penetration
- Renewal of calcium, phosphates, and fluorides
What is the result of enamel’s protective mechanism?
The dynamics of demineralization can be stopped or reversed.
What is enamel?
Acellular and predominantly mineralized epidermal tissue.
What is the function of calcium ions in enamel?
Transported as “seeds” of hydroxyapatite. They form a site for cystallization. Crystals enlarge and supplant organic matrix.
What is the building blocks of enamel crystal?
Molecular units of hydroxyapate
What can diffuse through the semipermeable enamel?
Various fluids, ions, and low-molecular-weight substances.
True or False:
Enamel is capable of self-repair.
False
Incapable of self-repair, but capable of remineralization.
What is the process of remineralization?
After initial stage of mineral loss, enamel fills void with new mineral: alterations in the dynamics of mineralization process through the incorporation of fluoride from various sources.
What is the process of initial demineralization?
- Enamel exposed to acids for a brief time
- Spacing and divergent orientation of crystals result in between rod and interrod enamel
- Makes enamel rod differentially soluble
What characteristic of enamel makes it more susceptible to acid penetration?
Certain areas of our enamel does not have perfect alignment: more susceptible.
What component of enamel are most susceptible to demineralization and first to be solubilized?
Carbonated components of the crystal.
Enamel’s crystalline makeup and rigidity/brittleness makes it more susceptible to what 4 things?
- Acid demineralization
- Attrition (“wear”)
- Erosion/abrasion
- Fracture
Enamel’s hardness is ___ times that of dentin’s.
5
What are the 5 functions of dentin?
- Forms bulk structure of the tooth
- Elastic foundation for the enamel
- Provides color (pale yellow)
- Protective barrier and chamber for vital pulp tissues
- Responds to external thermal, chemical, and mechanical stimuli
Which is harder, dentin or bone?
Dentin is slightly harder than bone, but not as hard as enamel.
Root dentin is covered with ________ and crown dentin supports the _________.
Covered with cementum and supports the enamel.
What makes up dentin?
45-50% inorganic apatite crystals
30% organic matrix
What is the function of intertubular dentin?
It is the structural component of the hydroxyapatite-embedded collagen matrix. Forms the bulk of dentin structure.