Flashcards in Basic Restorative Deck (120):
What is the of caries?
A process affecting the mineralised tissues of the teeth which is causes the action of microorganism on fermentable carbohydrates to produce acids
Which acids are mainly produced by the bacterias?
Which acid is the most damaging?
Which sugar is the most carigigenic?
Which bacteria are found in health?
Mainly gram pos facultative bacteria
Which bacteria are mainly found in fissure caries?
S sanguis and mitis
What are the common sites to develop caries?
Pits and fissures
What are rh four requisites to caries?
Susceptible tooth surface
Which bacteria are involved in caries mainly?
Lactobacillus sp.deep lesions
Acrinomycosis for root caries
How do primary enamel caries appear?
White spot lesion
What are the microscopic appearance of primary enamel caries?
Secondary enamel caries
What is in the initiation phase of enamel and how porous are they?
Normal enamel: 0.1%
Translucent zone: 1%
Dark zone : 2-4%
Periphery : 5%
Body zone: 25%
Surface zone : 1%
What is Sedondary enamel caries?
Enamel adjacent to dentine is less resistant to caries possibly due to the branching of dentinal tubules
WHat are the zones of dentine caries?
Superficial area : just beneath breached enamel
Central area: necrosis and destruction
Zone of penetration : tubules penetrated by bacteria
Advancing front : demineralised but not infected
What are the types of dentine?
Primary: bulk of dentine around pulp and also known as cicrumpulpal dentine
Sedondary dentine: develops after root formation and is continuos wit primary but slower rate of formation. Less regular than primary
Tertiary dentine: reactive to stimuli . Deposited either odontoblasts or replacement cells from pulp. Tubular pattern very irregular
T/F cementum rapidly decaclfies?
What are the risk factors for caries?
How can we assess the activity of a carious lesions?
Matt or shiny
What would caries that felt matt more likely indicate?
More active and indicated amount of pores
What does colour indicate?
Poor indicator but may indicate arresting
What does the consistent indicate?
Soft and leathery are more active
What are the defence mechanisms of the pulp dentine complex?
Tubular scleorsis: this is when the tubules become complety filled with calcified material and increases with age
Inflammation of pulp and pulpits
Where does the pulp come from?
Which caries has seen the biggest reduction on orevelance?
How much do fissure caries account for new lesions?
How does fissure caries start?
Bilaterally along walls as inverted cone shape
What does tooth brushing prevent?
Smooth surface caries
What is the reasonnfor change in caries?
Use of fluorides
When does fissure caries occur?
Two school of thought
1. Occlusal caries incidence peaks during and immediately after eruption
2. Occlusal caries incidence remains high and unremitting
Which ways can we diagnose caries?
Invasive and non invasive
What are the invasive caries diagnosis techniques?
What are the non invasive caries detection?
What is the problem with using a probe in fissure caries?
False positives as probe may stick in fissure due to normal anatomy
Misses dentinal caries
Possibility of breaking the soft surface zone and introduce cariogenic bacteria
How does visual inspection work?
Clean dry tooth
Must see staining and se calcification around the fissure
How does magnicficationwork?
Fissure caries detection improves and times 4 is thought to be the best
What magnification does an intrs oral camera use?
What magnification does an operating microscope use?
How helpful is radiographs in fissure caries ?
Only useful for occult lesions but otherwise not great since
1. Superimposition or buccal and Palatal enamel
2. Often only seen when caries into dentine
3. Small changes in X-ray tube head can make small lesions disappear
How effective is trans illumination?
Good for interproximal caries on ANTERIOR teeth
But POOR in POSTERIOR teeth
What must the ambient light be for trans illumination?
How will a caries free tooth appear compared to a caries tooth within trans illumination?
Caries free will glow
What is an example of trans illumination?
Compared to x ray how good is FOTI ?
17% enamel lesions detected
48% of dentine
What are the electronic methods for caries detection based on?
Carious teeth contain pores of enamel which saliva can pass through and this conduct small electrical currents
How effective are the electronic methods for caries detection?
HIGH SENSITIVITY !!!!! Can be used to monitor progress
What is the diode laser fluoresce?
Uses a laser of 680nm
Carious tooth structure is diff to normal
Fluorescence changes are measured and converted to an analogue scale
Low reading: sound
High reason: caries
80% sens and spec
But no diagnostic threshold and mainly used for occlusal lesions in conjunction with other technique
How does vista proof work?
High energery violet light used
Hat wave,length of light is used in vista proof?
What does vista proof show?
Porphyrin metabolites show red
Natrual tooth is green
What is th best way for carious detection using non invasive ways?
Clean dry tooth
When would invasive methods for caries detection be used?
High risk population or STRONG suspicion of caries in that tooth
What are the treatment options for fissure caries?
When would you observe for fissure caries?
You don't since cannot see it well
How does laser therapy work for fissure caries?
Causes carbonate and mg depletion
Reorganises apatite structure
Raises pulp temp by not more than 1 degrees
What materials can you use for a sealant restoration?
How does a sealants restoration work?and how much surface does it occupy?
Treatment of the enamel and dentine caries in a discrete part of the fissure pattern
Amalgam occupies 25%
What are the advantages of sealant restoration?
Minimal cavity prep
Tooth not weakened
What do we polish restrorstions?
For aesthetics,minimise plaque retention, and gingival irration, remove over hangs,
What are the options for increasing amalgam retention?
Slots: no greater than 1mm
How effective is the Circumfrential slot?
Same resistance as 4 pins but more sensitive to displacement during matrix band removal
What are amalgam pins?
Amalgam is used for the retention and similar placement to cone tonal pins
How's does the resistance to displacement for the amalgam pins compare to the conventional prins?
What are the dimsjonas for amalagmpins?
1.5-2 mm deep
How wide and deep do your slopes and steps need to be?
2.0 mm wide
What are bonded amalgams?
Where you use a bonding agent to aid retention of amalgam
T/F the bond strength between the amalgam and bonding agent is weaker than that of the tooth and bonding agent?
T/F there is less stress on the bond between amalgam and bonding agent than compared to composte?
What type of bonding agents would you use for bonded amalgams?
What to dentine pins provide?
Mechanical retention and resistance
How do dentine pins work?
Mechanical interlocking of amalgam into undercuts on the pin
What is the pins retention dependant upon?
Resiliency and firmness of dentine
What are the three types of dentine pins?
T/F self threading are less retentive than friction locked?
Self threading are the most retentive
What is the optimum depth of the dentine pins into dentine?
What is the optimum length of pin into amalgam?
T/F larger diameter pins are more retentive?
How many pins per missing cusp should be placed?
1 or marginal ridge/line angle
What is the maximum of pins in a tooth?
How far apart should pins be and what are the other requirement when placing pins?
1mm inside DEJ
1mm inside external Root is apical tonCEJ
2mm into dentine and amalgam
2mm from opposing tooth
How much dentine between pin and ADJ?
What angle should you place pins?
What can you cost the pins in?
MDP Panavia or
How much amalgam is needed ontop of the ion for replacing a cusp?
What speed hand piece do you use for pins?
What are the problems with pin placement?
Voids around pin
Pin at amalgam surface
What are the matrix bands available?
How long to extensive amagalsm last?
Where do class 2 lesions occur?
Least one of the interproximal surfaces on posterior teeth staters just below contact point
How can we classify caries lesions?
E1: outer hand of enamel
E2: inner half of enamel
D1: 0.5mm into dentine
D2: more than 0.5 but not within 0.5mm of pulp
D3: more than 0.5mm within pulp
How can you diagnose interproximal caries?
Laster fluoresce eg diagno dent
Temporsry tooth separation
How long does it take caries to reach ADJ in adults vs children?
Adults: 6 yrs
Kids: 4 yrs
What are the options for class 2?
Class 2 with key
Class 2 with self retentive box
Pre fabricated eg inlay
What percentage of class 2 amalgams have fractured cusps?
Occur at any age but most frequently affect molars
Which types of restorations have the biggest number of cusp fracture?
How does the tunnel prep work?
Intact marginal ridge
What was the tunnel prep initially deigned for?
What are the problems with tunnel prep?
Cannot visualise whole lesions
Not sure if cairies free
Cannot assess the strength of remsning tooth
Secondary carie within 3yrs
What are thr indications for posterior composite?
Small and moderate sized class 2
Patient allergic to metal s
Unsupported enamel may be strengthened by acid etch technqie
Not possible to obtain retention
What are the contr indications to posterior composites?
Patients with high caries risk
Cavities where cannot get isolation
Multiple large restrorstions with cuspal contact
What are thr problems with large class 2 composites?
What is the survival rate for amalgam vs composite?
15 yrs amalgam
6 yrs composite
What is blacks classification for caries?
Class 1: pit and fissure
2: mesial and distal premolar and molar
3: mesial and distal incisors and canine
4: involving incisal edge
5: occurring at cervical third
What are the contemporary caries classification?
What are the caries by site classification?
Site 1: pits fissures and enamel defects on occlusal or other smooth surfaces
Site 2: approximate surfaces for ant and post teeth
Site 3: cervical third of all teeth and any exposed roots
What is the classification by size?
0: initial lesion
1: minimal surface cavitation
2: moderate dentine
3: enlarged beyond moderate
4: extensive caries with loss of cusp
Why may anterior teeth need restoring?1
Where do class 3 lesions start?
Just at or below the contact point in the mid labial Palatal third
T/F the incidence for class 3 is higher than pit and fissure caries?
1-anterior teeth more accessible for OH
2: narrower contact ares
3: increased use of fluoridated tooth paste
Which patients are class 3 more common in?
How do you diagnose class 3?
Can see once into dentine as a darkness
What diagnostic methods can we use for class 3?
What probes are used for detecting class 2 and class 2 lesions?
Brialt and Weston
Nee to use a light pressure
How can you use trans illumination in class 3 lesions?
Light off dental mirror
What are the ways of restoring class 3?
When would we bevel class 3 cavity?
When the cavity extends to an area that is visible then bevel
Advantages: end on etching of enamel prisms, increases surface ares for bond, blends composte better, reduces micro leakage
BUT: increase cavity size
What lining materials can we use in class three?
Dentine bonding agents
Light cured GIC
What is an alternative to class three prep?
How can you gain retention for class 4?
Cervical groove in dentine
Which matrices can you use for class 4?
Polyester : straight or curved of incisal corner