Determination of basic properties of enamel

The thesis about different degree of enamel solubility in aciduric environment – the base of modern methodology of determination of caries resistance of enamel. According to this thesis the following methods of determination of caries resistance of enamel are used.

• The clinical symptoms of caries resistance of enamel (DMF and df indeces)

• Laboratory tests for determination of resistance of enamel - CRT-test , TER –test (determine the Solubility of enamel)

CRT – test( colour reaction time)

Methods of determination of CRT – test is based on the use of demineralizing solution with the acid-basic indicator of colour reaction and the degree of solubility of enamel of tooth shows (resistance of enamel) .

The aim: the estimation of the degree of solubility of tooth enamel (resistance of enamel)

Estimate the time, which is needeed for neitralisation of standart quintity of acid by ions which leave the enamel apatite during dissolution by this acid.

The armamentarium: 1Н solution of hydrochloric acid – НСl. micropipette, disc 3 mm ( diameter ) made from filtration paper, preliminary saturated with 0,02 % aquatic solution of crystalline violet ( during 30 sec) In a neitral environment it has violet color, in aciduric – yellow, stop-watch.

The technique. Tooth 12 should be cleaned from plague, dried and isolated from saliva. Disc, made from filtration paper should be applied on vestibular surface of tooth 12. The 1,5 ml of 1Н solution of HCl should be placed on a disc by micropipette. By means of stop-watch measure time from a moment placing of acid solution to the complete passing of color to pink-violet one.

Estimation of results. Check the time of chenging the color of disc (from yellow to violet) CRT > 60 sec – the low solubility but high cariesresistance, low caries risk;

CRT < 60 - the high solubility but low cariesresistance, high caries risk;

Technique of definition of the test of enamel resistance (the ter-test) – the visual estimation of enamel lesion

The aim: Estimation of degree of damaging of outer layer of enamel under influencing of acid.

The armamentarium: 1Н solution of hydrochloric acid – НСl., micropipette, 1 % water solution of methylene-blue, 10-point scale of tints of blue color, cotton tampons

The technique. Tooth 12 should be cleaned from plague, dried and isolated from saliva. The drop of 1Н solution of HCl and with diameter 1,5-2mm should be placed on vestibular surface of tooth 12, pure by the central line at the distance of 2 mm from cutting edge on a 5 seconds. After 5 seconds the drop must be removed by means a dry cotton tampon.

After that, the drop of 1 % of a water solution of methylene-blue should be placed on the pickled surface and healthy surface of enamel on a 5 seconds. The dye is removed by dry wadded tampon. The intensity of staining the defect of enamel is estimated by a 10-point scale of tints of blue color.

Estimation of results. Intensity of color of enamel should be compared with 10-point scale of tints of blue color

An estimation of results is expressed in points.

1-3 points - colourings in pale blue colour testify of high structurally functional resistance of enamel.

4-5 points - colourings in blue colour which defines average resistancse of enamel to caries.

6-7 points - colourings in dark blue colour, testify of low resistance of enamel and high risk of occurrence of caries.

More than 8 means very low resistance

Tests α=2

Which of the following is a local caries risk factor?

1. high maintenance of fluoride in a drinking water

2. low maintenance of fluoride in drinking water

3. unsatisfactory oral hygiene

4. presence of somatic pathology

5. hereditary factor

Which of the following is a caries risk factor?

1. well aligned dental arches

2. crowding

3. intact dental row

4. extracted teeth which are present in an oral cavity after trauma

5. correct answer is absent

Which of the following is a local caries risk factor?

1. high maintenance of fluoride in a drinking water

2. amount of the accepted carbohydrates

3. composition of saliva

4. presence of somatic pathology

5. mouth breathing

Specify, what amount of saliva is distinguished for the adult during twenty-four hours.

1. 500-800 ml

2. 1200-1300 ml

3. 1500-2000 ml

4. 1000 ml

5. 2000-3000 ml

Name the basic structural element of enamel

1. crystal of Ca

2. enamel prism

3. protein

4. collagen fibre

5. water

What kind of chemical elements influences the process of enamel maturing most of all?

1. fluor

2. vanadium

3. molybdenum

4. strontium

5. potassium

What is the ratio of Ca/P for caries resistant tooth enamel?

1. 6,7

2. 3,3

3. 1,67

4. 1,3

5. 2,1

Which of the following is a general caries risk factor?

1. high maintenance of fluor in a drinking water

2. high maintenance of carbohydrates in food

3. high maintenance of H-ions in saliva

4. high maintenance of organic components in enamel

5. high maintenance of inorganic components in enamel

Which of the following is a general caries risk factor?

1. low maintenance of fluor in a drinking water

2. high maintenance of fluor in a drinking water

3. high maintenance of H-ions in saliva

4. high maintenance of organic components in enamel

5. high maintenance of inorganic components in enamel

Which of the following is a general caries risk factor?

1. high frequency of consumption of refined carbohydrates

2. high frequency of consumption of sweet juice

3. high frequency of tooth brushing.

4. high frequency of diseases in a child.

5. All of the above.

Which of the following does not belong to a caries risk factor? predictor

1. high level of enamel mineralization,

2. high titre of microflora of oral cavity

3. high level of consumption of refined carbohydrates,

4. high level of caries intensity

5. All of the above.

Which of the following does not belong to a normal condition of oral cavity?

1. amount of saliva is during twenty-four hours is 230ml.

2. viscidity of saliva 4,0 units

3. amount of saliva per minute is around 1.0 mL

4. рН in the oral cavity is 7,0

5. the ratio of Ca/P in enamel is 1,67

Which of the following does not belong to a normal condition of oral cavity?

1. amount of saliva for the period of twenty-four hours is 1630 ml.

2. viscidity of saliva 8,0 units

3. amount of saliva per minute is around 1.0 mL

4. рН in the oral cavity is 7,0

5. the ratio of Ca/P in enamel is 1,67

Which of the following does not belong to a normal condition of oral cavity?

1. amount of saliva for the period of twenty-four hours is 1630 ml.

2. viscidity of saliva is 4,0 units

3. amount of saliva per minute is around 1.0 mL

4. рН of mouth 7,0

5. the ratio of Ca/P in enamel is 1,33

Which of the following condition of oral cavity of a 5 year-old child does belong to a caries risk predictor?

1. amount of saliva for the period of twenty-four hours is 1630ml.

2. viscidity of saliva 8,0 units

3. amount of saliva per minute is around 1.0 mL

4. рН of mouth 7,0

5. the ratio of Ca/P in enamel is 1,67

Which of the following condition of oral cavity of a 10 year-old child does belong to a caries risk predictor?

1. amount of saliva for the period of twenty-four hours is 1630ml.

2. viscidity of saliva 3,5 units

3. рН of mouth 7,0

4. the ratio of Ca/P in enamel is 1,67

5. the score of hygiene index - 2,0

Chose the date of hygiene index which described the unsatisfactory condition of oral cavity.

1. 1,0

2. 1,4

3. 2,0

4. 2,2

5. 2,6

Which of the following factors can reduce permeability of enamel?

1. electrophoresis

2. dental plague

3. ultrasound

4. carbohydrate food

5. age

At what minimum value of СА/Р coefficient does destruction of crystals of hydroxyapatite take place?

1. 1,67

2. 1,57

3. 1,53

4. 1,33

5. 1,25

Which of the following formulas is the formula of hydroxyapatite of enamel?

1. Са8НРОН4

2. Са10(РО4)6(ОН)2

3. Са10(РО4)8(ОН)2

4. Са10(ОН)2

5. Са10НРО4

What does the concept " Cariesresistance" mean in general?

1. stability of enamel to the action of acids

2. stability to the action of alkalyes

3. stability to the action of caries risk factors

4. stability to the abrasion

5. quantity of caries cavities

Name local factors lead to the development of caries

1. climatic terms

2. change of amount and quality of mouth liquid

3. diet and drinking-water

4. inherited and somatic diseases

5. life-style

Name local factors lead to the development of caries

1. climatic terms

2. diet and drinking-water

3. unsatisfactory hygiene of oral cavity

4. remnants of food in the oral cavity

5. inherited and somatic diseases

Which saliva buffer system provides 80% of saliva buffing properties?

А. Bicarbonate

В. Protein

С. Phosphate

D. Nitrate

Е. Carbohydrate

Which of the following ions does the initial acid attack preferentially dissolve?

1. magnesium

2. calcium

3. phosphate

4. fluor

5. potassium

What type of fluid does the parotid gland secrete?

1. fluid containing eletrolytes, but is relatively low in organic substances

2. mixed serous and mucuos fluid,

3. fluid containing greater proportion of mucous than the other major glands.

4. the type of fluid depend on general condition of subject.

5. Correct answer is absent

What type of fluid does the sublingual gland secrete?

fluid containing eletrolytes, but is relatively low in organic substances

mixed serous and mucuos fluid,

fluid containing greater proportion of mucous than the other major glands.

the type of fluid depend on general condition of subject.

Correct answer is absent

What type of fluid does the submandibular gland secrete?

fluid containing eletrolytes, but is relatively low in organic substances

mixed serous and mucuos fluid.

fluid containing greater proportion of mucous than the other major glands.

the type of fluid depend on general condition of subject.

Correct answer is absent

What is the volume of mineral and organic components in a saliva?

1. 0,1%

2. 0,5%

3. 1%

4. 1,5%

5. 5,0%

What is the volume of water in a saliva?

1. 0,5%

2. 35%

3. 50,5%

4. 99, 5%

5. 100%

What is the flow rate in nightly sleep?

1. 0,1 ml/of mines

2. 0,25 ml/of mines

3. 0,50 ml/of mines

4. more, than 0,50 ml/of mines

5. more, than 100 ml/of mines

What is the part of day with the highest flow rate ?

1. the highest flow rate in the morning, between 8 and 10 o’clock

2. the highest flow rate in mid-afternoon

3. the highest flow rate around 4:00 A.M.

4. the highest flow rate in mid-night

Name the condition with absence of saliva

1. bulimia

2. pneumonia

3. xerostomia

4. ptyalism

5. correct answer is absent

How many buffer systems are there in saliva?

1. One

2. Two

3. Three

4. Four

5. five

What is the most important buffering system in saliva?

1. the phosphate system

2. the carbonic acid / bicarbonate system.

3. the protein system

4. all systems with equal importance

5. correct answer is absent

When the stimulation by paraffin chewing or by adding droplets of a sour liquid (3% citric acid) on the back of the tongue can be done for estimation the fuctions of saliva?

1. When Measurement the buffer capacity

2. When measuring the flow rate

3. When Measurement saliva remineralizing ability

4. When Measurement the viscosity of saliva

5. The methods are used in all techniques.

What is the maximum score of the test “ Saliva remineralizing ability” (CDRRE-test)

for caries-resistant people?

1. 1 day

2. 2 days

3. 3 days

4. 4 days

5. 5 days

What is the minimum score of the test « Saliva remineralizing ability» for caries- susceptible people?

1. 1 day

2. 2 days

3. 3 days

4. 4 days

5. 5 days

What kind of salivary enzymes does initiate intraoral digestion of carbohydrates?

1. amylase

2. lyzocim

Control questions (α =2).

1. Dental caries as a pathological process

2. Caries risk factors (general and local).

3. The role of saliva in process of caries development

4. The sources and composition of saliva

5. The functions of saliva

6. The methods of estimation the features of saliva

7. The role of resistance of hard tissues on a process of caries development

8. The basic properties of enamel

9. The methods of estimation the features of enamel

Independent work