Extrinsic and Intrinsic stains and cosmetic polishing

Question 1

Identify the difference between intrinsic and extrinsic stain

Answer 1

Intrinsic:
• Are incorporated into the tooth structure
• Created when tooth is forming

Extrinsic:
• Pigment deposits found on tooth surface
• Oral cavity is subjected to many exogenous substances that stain the teeth e.g coffee
• The oral flora contains many types of chromogenic deposits which cause stain deposits

Question 2

How do you test the difference between an intrinsic and extrinsic stain?

Answer 2

Intrinsic:
• Cannot be removed with a scratch test
* May be red/ pink caused from a dead dental pulp

Extrinsic:
• Scratch text: run lateral tip of explorer on tooth surface with light, oblique strokes
* A small amount of the stain will be removed

Question 3

List 4 predisposing factors that an operator needs to consider when thinking about Extrinsic staining.

Answer 3

1. Salivary dysfunction
2. Poor oral hygiene
3. Tooth anatomy
4. Habitual

Question 4

Describe salivary dysfunction as a consideration of extrinsic staining

Answer 4

• Decreased output may be caused by a local or systemic disease, radiation and medication
* Diminished salivary output contributes to extrinsic discoloration

Question 5

Describe poor oral hygiene as a consideration of extrinsic staining

Answer 5

Inability to remove stain producing materials and inadequate cleaning and polishing causes discolorations

Question 6

Describe tooth anatomy as a consideration of extrinsic staining

Answer 6

• Pits and fissures hold onto stains from coffee/ smokes, beverages
* Enamel defects just hold onto stain producing foods

Question 7

Describe habits as a consideration of extrinsic staining

Answer 7

• Smoking
• Regular coffee consumption
• Tea consumption
* Red wine consumption

Question 8

List the common causes of extrinsic stains (5)

Answer 8

• Dental plaque and calculus
• Foods and beverages
• Chromogenic bacteria
• Topical medications (chlorhexidine mouth rinse)
* Metallic compounds: industrial exposure to iron/ manganese and silver may stain teeth black. Mercury and lead dust can cause a blue-green stain

Question 9

Elaborate on Chromogenic Bacteria as a cause of extrinsic stains

Answer 9

• Causes stains typically at the gingival margin of the tooth
• Most common is a black stain: caused by actinomycin species. The stain is made of ferric sulphide and is formed by the reaction between hydrogen sulphide and iron in the saliva and gingival exudates
• Orange/ yellow: stain is less common and is caused by chromogenic bacteria flavobacterium lutescens or food pigments
* Green: associated with fluorescent bacteria and fungi such as penicillin and is usually associated with poor oral hygiene

Question 10

Elaborate on topical/ systemic medications

as a cause of extrinsic stains

Answer 10

• Chlorhexidine rinse causes brown staining after several weeks of use particularly on acrylic and porcelain restorations
• Iron- containing oral solutions cause black stains
• Silver nitrate (black stain) and stannous fluoride (brown stain)
• Systemic medications like minocycline

Question 11

List the common causes of intrinsic stains

Answer 11

• Dental materials: Amalgam and composite GIC
• Erosion/ caries
• Trauma
• Infections
• Medications 
• Excessive ingested fluoride
• Genetic defects/ hereditary disease
* Nutritional deficiencies and other disorders (anemia and bleeding disorders, bile duct problems, pregnancy complications)

Question 12

Describe erosion and caries as an intrinsic stain

Answer 12

• Erosion of enamel can be caused by frequent ingestion of acidic foods and beverages removing enamel and displaying yellow dentine
* Patients with ortho show a great risk of caries because of inadequate plaque removal

Question 13

Describe trauma as an intrinsic stain

Answer 13

• Severe enamel hypoplasia; clinically referred to as a turners tooth
• The patient had an intrusion injury of the primary central incisor during childhood that interrupted the development of the secondary central incisor

• When a tooth is knocked, damage to the pulp occur
* This can cause intrapulpal hemorrhagic and iron sulfide deposition along the dentinal tubules, producing a bluish black cast

Question 14

Describe infections as an intrinsic stain

Answer 14

• Periapical infections of the primary teeth can disrupt normal amelogenesis of underlying permanent successors
• Maternal rubella
* Systemic post natal infections; measles, chicken pox, streptococcal infections

Question 15

Describe tetracycline staining as an intrinsic stain

Answer 15

Caused by the ingestion of Tetracycline (Class of Antibiotic) Medication when the patients were aged 3-5 years of age

Question 16

Describe genetic defects and hereditary diseases as an intrinsic stain

Answer 16

• Genetic defects in enamel or dentin formation include amelogenesis imperfecta , dentinogenesis imperfecta , and Dentinal Dysplasia
• Amelogenesis imperfecta and Dentinogenesis imperfecta affects both primary and secondary dentitions and represent a disturbance in the formation of the Enamel and Dentine Respectively

Question 17

List and describe what Pre-treatment Considerations an operator must consider before proceeding with Oral Prophylaxis

Answer 17

1. Discuss medical care:
   Are there any medication or mouth rinses that may be contributing towards staining? e.g Chlorhexidine or Stannous Fluoride
2. Discuss diet and habits:
   Extrinsic staining caused by foods, beverages, or habits should be addressed with the appropriate Oral Hygiene advise (rinse after coffee or chew sugar free gum) or encouragement of smoking cessation
3. Discuss tooth brushing and ID cleaning:
   Effective tooth brushing twice a day with a dentifrice helps to prevent extrinsic staining. Electric toothbrushes help slow stain development. If spaces allow, ID Brushes should be recommended

Question 18

Define Oral Prophylaxis and briefly discuss the purpose

Answer 18

Definition
Tooth polishing is the smoothing of all exposed tooth surfaces with a rubber cup, a brush, driven by a slow-speed hand piece or by an air polisher

Purpose
• The purpose of an oral prophylaxis is the cleaning of exposed and unexposed surfaces of the teeth by scaling and polishing
• It aims to remove primary (biofilm) and secondary factory (calculus, stains) to help prevent Periodontal disease
* When teeth are smooth there is less potential for further plaque (bio film) accumulation

Question 19

Discuss the precautions of prophy’s

Answer 19

• Dental polishing was considered important for the removal of plaque and stain prior to a fluoride treatment to insure adequate uptake of fluoride in the enamel
• Recent research has shown that polishing does not improve the uptake prior to a professionally applied fluoride treatment
Continuous polishing may cause morphological changes in the teeth by abrading tooth structure and removing 1m of the fluoride layer of the enamel

Question 20

Describe considerations of dental prophylaxis

Answer 20

• Polishing could destroy valuable tooth structure as well as damage cosmetic restorations
• Warn patients that coronal polishing is no longer performed for every patient as routine, only in the case of evident stain build up

• Patients may expect to have their teeth polished after scaling
– If a patient has no stain explain to them that over polishing can contribute to loss of tooth structure
– If they remain insistent use a prophylaxis paste with a fine grit or use toothpaste only to polish their teeth

Question 21

List 4 patient considerations an operator needs to be aware of after Oral
Prophylaxis

Answer 21

1. Floss the whole mouth
2. Rinse the whole mouth and suction the patient’s mouth
3. Ask them if they can feel any residual prophy paste in their mouth, if so rinse again
4. Check to make sure there is no paste on their face before they leave your dental chair

Question 22

Describe how to perform effective Oral Prophylaxis

Answer 22

1. Wet the tooth first and it should remain moist during polishing to avoid frictional heat
2. Rotate the entire handpiece, as you work around a tooth, from distal towards mesial surface. Pause for a second on the distal, buccal and mesial surfaces
3. Polishing rubber cup should be gently pressed against the corresponding tooth surface to reach subgingival area at least 0.5 mm and interproximal sites as much as possible

Question 23

List the implements needed to perform prophy

Answer 23

Hand pieces for polishing

Prophylaxis cups

Prophylaxis brushes

Prophylaxis paste

Prophylaxis holders

Question 24

Describe hand pieces for polishing as an implement for prophy

Answer 24

• Polishing handpieces should be operated at 3000 RPM

* Faster can be dangerous as it may cause patient discomfort, gingival abrasion

Question 25

Describe Prophylaxis pastes as an implement for prophy

Answer 25

• Old pastes used to contain pumice and water. This was very abrasive and would reduce gloss on many restorations
• Today, pastes are used with cups and contain fluorides
• The pastes are available in fine, medium and course grits
• Some patients may be sensitive or not want the colours, flavourings, and additives
• Gluten intolerant patients - use EnamelPro

Question 26

List the various types of dental stain colours (5)

Answer 26

Yellow

Green

Black line

Tobacco

Brown

Question 27

What is the recommended removal for a yellow stain?

Answer 27

• Manual debridement

* Polish with fine or non-abrasive polishing agent

Question 28

What is the recommended removal for a green stain?

Answer 28

• No scaling; remove with toothbrush debridement
• Avoid abrasive polishing agents
• Use materials with remineralising agents
* Include daily fluoride regime

Question 29

What is the recommended removal for a black line stain?

Answer 29

• Manual debridement with ultrasonic or hand instruments

* Fine-to coarse abrasive polishing agent

Question 30

What is the recommended removal for a tobacco stain?

Answer 30

Manual debridement and/or fine-to-course abrasive polishing agent

Question 31

What is the recommended removal for a brown stain?

Answer 31

• Gentle scaling

* Non abrasive polishing agent