Toca Final Review

Count DMFT

12


Be sure to count one per tooth (no double dipping). Exclude sealants, third molars, and incipient caries For DMFS you can double dip and count surfaces and for DMFS don't count incisal edge

Composition of Calcium Hydroxyapatite:

Ca10(PO4)6(OH)2

w/ Fluoride Ca₁₀(PO₄)₆F<sub>2

Crystals are organized in Rods and prisms</sub>

Statement 1: The basic organization units of dentin are the rod and interrod dentin 

Statement 2: Enamel is built from closely packed and long, ribbon-like

carbaonoapitite crystals which are 60-70 nm in width and 25-30 nm in thickness

and have hexagonal symmetry.

Statement 2 only

Statement 1 would be correct if it were ENAMEL

Dentin’s basic organization would be dental tubules

What is Marsh Ecological Plaque Hypothesis?

Microbiome imbalance due to ecological stress

Note: Shift from symbiosis to dysbiosis

Which of the following statements about the Relative Dentin Abrasivity of toothpastes is

TRUE?

Statement A: Toothpastes with an RDA value of above 250 are considered safe for daily use

Statement B: Lower RDA value indicates a more abrasive toothpaste

Statement C: The maximum RDA value allowed for a toothpaste is 150

Statement D: Toothpastes with RDA below 70 are classified as low

Answer: D Low Abrasive
Low Abrasive 0-70 RDA

Medium Abrasive 71-100 RDA 

Highly Abrasive 101-150 RDA
Regarded as a harmful limit 151-120

According to the ADA caries classification system, initial caries lesions are the earliest

detectable lesions with net mineral ___radiographic presentation of these caries in the proximal surface can include: 

E1, E2, D1

Notes:
Advanced Lesion through the Dentin
Moderate Lesion through D2

You conduct a comprehensive oral exam and caries susceptibility test after providing chewing gum to the patient and collecting saliva for 5 min, and gather a total of 4 ml. Based on this result, determine the rate of saliva collected and assess the salivary rate.

The type of saliva collected was stimulated because they were chewing gum, and it was below the normal stimulated flow rate because it should be between 1-2 ml/min

Note: Divide ml collected by Minute

What bridges early colonizing and late stage pathogens?

Fusobacterium nucleatum

List the stages and timelines for biofilm development.

a. Pellicle formation (1 um thick, forms w/ salivary proteins)

b. Attachment of early colonizers (0-24 hrs)

c. Formation of microcolonies (4-24 hrs)

d. Diversification of microcolonies (1-7 days)

e. Mature biofilm (1 week)

****Statement 1: Outer caries layers are the  infected dentin bacteria, and most of the infected structure (intertubular and peritubular dentin) is demineralized

Statement 2: The subtransparent zone presents granular-shaped crystals in normal dentin is found beneath the transparent zone?

Both Statements are true

Which ducts drain mostly mixed saliva

Wharton’s Duct

Notes:
Serous gland - Parotid gland - Stensen’s duct

Mixed gland - Submandibular gland - Wharton’s duct

Mucoid gland - Sublingual gland - Rivinus ducts

Xylitol causes bacteria to…..

form intracellular vacuoles and cell degradation

The composition of enamel by weight is…

a. Enamel (critical pH - 5.5)

i. 95% : inorganic

ii. 4% : organic

iii. 1% : water

Note:
Volume 97% Mineral and 3% by volume

The composition of Dentin by Weight is…

Dentin (critical pH- 6.2)

i. 70%: inorganic

ii. 20% : organic

iii. 10% : water

Tooth has a birthday on September 12, what is its ICDAS?

Mandibular Canine, 5

Birthdays of all teeth

What is this Study?

Turku Study from Finland

Who is this guy?

Pier Fauchard

Father of Modern Dentistry

Disagreed with the worm hypothesis

Wrote Surgeon Dentist

Which toothbrush is better, manual or electric tooth in terms of reducing plaque and gingivitis?

Electric is better in reducing both

What is the lesion’s name in the picture where the arrow is pointed at?

Note: White spot lesion is under the tooth so the surface is still intact

What scale is used for dry mouth

Challacombe Index

1. List the 10 items evaluated with the Challacombe Scale

a. Mirror sticks to buccal mucosa

b.  Mirror sticks to tongue

c.  Saliva frothy

d.  No saliva pooling in the floor of mouth

e.  Tongue shows generalized shortened papillae

f.  Altered gingival architecture

g.  Glassy appearance of oral mucosa/palate

h.  Tongue lobulated/fissured

i.  Cervical cavitations on more than two teeth

j. Debris on palate or sticking to teeth

Note:
1-3 Mild

4-7 Moderate

8-10 Advanced

Which tooth on the radiograph has the right development of caries, and what is its birthday?

Maxillary second premolar 11-12

What buffer contributes the most at a pH of 5-7?

Bicarbonate buffering system- excreted at higher flow rates (pH 5-7)

Note:
Phosphate buffering system- concentration decreases w increasing flow (pH 6-8)

Bicarbonate buffering system- excreted at higher flow rates (pH 5-7)

Protein buffer system- isoelectric point pH 5-9, major contribution below pH 5

Extra Stuff that she mentioned that could be on the exam

Smear Layer

Usually forms on dentin after a procedure

CaF 2 layer forms almost immediately following exposure to fluoride, such as brushing teeth, and slowly dissolves within a period of two hours.

Vipeholm’s Study

One of the large-scale research study done in Sweden that showed relationships between

diet, sugar intake, and frequency of caries (controversial study)

Hopewood House Study

Orphan Children in Australia were put on a diet of nutritious food and they had a DMFT score of 0.58 compared to Sydney’s 9.5

Takeuchi Japan Study

During WW2,
Less access to sugar so less cavities in solidiers. Shows relationship between sugar consumption and caries

Tristan Da Cunha

An isolated island where residents had low levels of dental caries then when a volcano hit they got exposed to refined and thus higher levels of sugar, leading to an increase in dental caries. .

Kikuyu Tribe vs Masai Tribe

Kikuyu (K=Karbs) rich diet vs Masai Tribe had a protein rich diet

Willoughby d Miller

Nonspecific plaque theory, plaque was main caused of caries from bacteria in GENERAL

Fluoride Toothpaste of different concentrations for preventing dental caries

Fluoride toothpaste is better should be used in balanced for children

Fluroide Mouthrinses, Gels, Varnishes, and Supplements

All are factors that have evidence in caries reduction

Fluoride Toxicity

Toxic Vs Lethal Dose

Adult Acute Lethal Dose 5-10 NaF (2.5 - 5 g) F
Children = 36 mg/kg NaF (15m g F/kg)

Outer Lesion of Carious Dentinal Tubule

Outer carious layers or infected dentin: Bacteria have penetrated this region. Most of the structure lost due to demineralization produced by bacterial acid

Turbid Inner Lesion (Affected Dentin)

Turbid Zone has lost the peritubular dentin and the intertubalar dentin is most demineralized. NO BACTERIA PRESENT

Transparent Inner lesion (Affected Dentin)

Transparent zne retains its peritubular dentin, and tubule may be partially filled with mineral.

Minerals are whitlockite crystal that have a lower hardness and content of calcium than apatite

can be left untouched in dental procedure

Subtransparent Inner lession Affected dentin

The subtransparent zone presents granular shaped crystals and normal dentin is found beanth