MI Preventative and Operative Flashcards
Why didn’t early hunter gatherers have a large presence of dental caries?
Due to the fact that hunter gatherers did not have a source of simple carbohydrates. This means that cariogenic bacteria were unable to develop, as cariogenic bacteria feast on simple carbohydrates.
What are the steps to radio-graph assessment?
- Exposure
- Detector orientation
- Horizontal detector positioning
- Vertical detector positioning
- Horizontal beam angulation
- Vertical beam angulation
- Central beam position
- Colimator rotation
- Sharpness
- Overall diagnostic value
What are the steps to gingival assessment?
C - colour
C - contour
C - consistency
T - texture
E - exudate
What is the difference between sign and symptom?
Symptom - are reported by the patients
Signs - are detected by the physician
What are the steps to ILA?
- Patient
- CC
- MHx
- SHx
- DHx
- Exam
What is TRIM?
TRIM is an acronomy for:
Timing
Relevance
Involvment
Method
What is differential diagnosis?
It is a process where a physician is able to assign probability of one illness in comparison to others accounting for patients sympotms.
What is a white spot lesion?
A white spot lesion is an incipient caries lesion, it has a dull opaque chalky appearance and occurs due to demineralisation of enamel caused by cariogenic bacteria
What is the pathogenesis of caries?
- Cariogenic bacteria requires simple sugars for anaerobic respiration
- Glucose is processed through glycolysis in the cariogenic bacteria
- Glucose is converted into 2 pyruvate
- In order to than convert NADH electron carrier into NAD+, pyruvate is converted into lactic acid
- Lactic acid accumulates in the cariogenic bacteria and is released into the oral environemnt
- Lactic acid has pH of about 2.35 which is slower than the critical pH of hydroxyapatite which means Lactic acids is able to cause dissociation of hydroxyal groups in hydroxyapatite which leads to demineralisation of the enamel
How can we remineralise a tooth?
In presence of Calcium, Phopshate and/or Fluoride in the biofilm or in salivary pool, if pH of above 4.5 is restored the tooth would be immediatley remineralised
What is the significance of dental pelicle?
It is able to provide some protection to the enamel. It also allows for binding of bacteria to the surface of the tooth
Why is fluoride so effective?
- It is able to stop cariogenic bacteria metabolism
- Drive remin
- Create fluoride salivary pool
Why are incipient carious lesion look so much opaque?
Due to increased porosity. Increased posicity of enamel traps water which has a different refractive index which makes it look more dull
Why is calcium still needed for fluoride incorpiration?
Fluoroapatite still needs calcium and phosphate
How would you describe WSL
L - location
C - colour
T - texture
C - contour
What is stephan’s curve?
It is a graph that shows what happens with oral pH after sugar consumption
How is calculus formed?
- Acid attack occurs
- Statherin releases Ca
- Excess calcium is able to percipitate on the biofilm as it can be used as an epitatic agent
What are the steps of rubber dam critique?
- Dam preperation (hole positionin, punching)
- Clamp selection (choice, gingival trauma, retention)
- Clamp placement (gingival trauma)
- Dam placement (alignment of dam)
- Frame placement (positioning of frame)
- Dam finish (isolation of appropriate teeht, moistture control)
- Dam removal
What is an ecological niche?
It is space where some organisms are able to thrive in, such are present in oral environment on tooth surfaces, calculus
How did the demin/remin system develop?
Due to an acidic diet of hunter gatherers, buffering to accommodate for it.
How can we describe teeth?
We can describe teeth as a mechanically functional unit of the mouth.
Why do we have protein and moisture in between the enamel rods and the dentine?
Because protein and moisture between enamel rods and dentine create good physical properties. These properties are resistance to compressive and tensile stresses which occur during mastication.
What are dentinal tubules?
They are spaces that project from pulp and through the dentine. They are comprised of intertubular dentine which is a mineralised collagen matrix and intratubular dentine which has small hydroxyapatite crystals.
What type of fluid flow from the pulp?
The fluid that is saturated with calcium, phosphate and other materials. These materials could be used for deposition of minerals.
What are the major salivary glands?
Parotid (serous), Submandibular (mixed) sublingual (mixed).
Where are the Von Ebners glands located?
Circumvallate papillae and they are serous.
What are some of the functions of saliva as a lubricant?
It reduces wear and allows for swallowing.
What are the functions of the salivary proteins and dissolved materials?
- Acid neutralisation
- Promotion of remineralisation
- Creation of pellicle
- Antibacterial properties
What is a climax community?
It is a stable but still dynamic community of biofilm on the tooth surface
What type of buffer does stimulated saliva?
Bicarbonate
What type of buffer is in unstimulated saliva?
Phosphate
In what conditions can enamel remineralise?
In super saturated conditions of the close system
What do impurities do to enamel?
Impurities make enamel weaker
What is the sialo-microbial-dental complex?
They are interaction between saliva, biofilm and tooth.
What can change the balance of the oral environment?
- More refined, softer foods
- Refined CHO
- Increase in fermentation
What occurs during acidification of biofilm?
- “Good bacteria” is lost
- Selection for acidogenis and aciduric micro-organism occurs
- Resting pH = becomes more acidic
Why do sub-surface lesions looks so frosty?
Due to higher amount of water in porosities created during demineralisation – the lesion seems white in appearance.
Why is erosion so effective?
Because it occurs in an open system, where acid is able to remove the minerals used for remineralisation entirely
What is the diffenrence between intrinsic/extrinsic acids and plaque acid?
Plaque acid is less strong than intrinsic/extrinsic acids, thus take longer to effect enamel
What are the biochemical interaction that cause caries?
- Acidification of biofilm
- This leads to drop in pH below the critical pH
- Dissosiation of the appetites of the enamel occurs
- Process can be reversed if the biofilm is removed and acidity is neutralised due to ‘closed system’
- IF process is not stopped the carries will progress into the dentine
- When the caries is well into the dentine the process can not be reversed
- This leads to destruction of structure of the tooth, and when force is placed on that area, it cavitates
What are the biochemical interactions that cause erosion?
- Intrinsic/extrinsic acids are able to change the pH in the oral cavity
- The pH drops below the critical pH, which removes biofilm and effects the apatites of the tooth
- This causes the dissociation of appetites
- Super saturated conditions for remineralisation are removed due to ‘open system’
- Result - scooped shiny apperance
What is infected dentine?
It is a demineralised & stained dentine with denatures collagen framework. Bacteria is usually present in that dentine.
What is affected dentine?
It is dentine just below the infected dentine. The peritubular and intertubular dentine is demineralised but the collagen framework is still intact. It is transparent in appearance and usually has no bacteria.
Summarise the factors that show that the patient is not at risk of caries.
- High biodiversity in the biofilm
- Low amount of acidogenic & aciduric bacteria
- High numbers of Alkali producing bacteria
- High resting pH of biofilm
Summarise the factors that show that the patient is at risk of caries.
- Decrease in biodiversity of biofilm
- Proliferation of acidogenic and aciduric bacteria
- Reduction of Alkali producing bacteria
- Resting pH of biofilm is reduced
What does it mean to have a healthy oral environment?
Having a healthy oral environment means having a balanced oral environment through both mineral maintenance as well as disease protection with use of sialo-microbial-dental complex.
How can the biofilm change?
When simple carbohydrates are introduced, the biofilm becomes more acidic.
How can saliva change?
Salivary flow could change due to systemic diseases, use of medications, certain lifestyle choices like smoking or as a result of treatment like chemotherapy or radiation therapy.
How can you tell if biofilm is cariogenic?
- White spot lesions in self cleansing areas (could also indicate poor saliva quality)
- Interproximal caries
- Cavitated carious lesions
- Any new restorations
- VIsual appearance
- Cariogenic diet
What can be used to test the quality of saliva?
The best test to use to measure the quality of saliva is the Saliva Check Buffer (GC International test)
Quality of saliva can eb also be assessed visually – for example dry/cracked lips could be an indication of dehydration (low salivary flow).
What is the main driver of caries?
Lifestyle changes
What are the mechanism of action of fluoride?
- Enhancing remin
- Inhibitng demin
- Anti-microbial at high concentration
- Intra-oral fluoride reservoir
What is the mode of action of APF?
It is able to use it’s acidity to dissolve hydroxyapatite and use calcium for creation of fluorapatite – this is great for xerostomic conditions.
How does fluoride reservoir help during acid attacks?
When acid attacks occur, the salivary proteins that hold calcium are broken down. Thus if there is a fluoride reservoir – when calcium is freed from the protein, fluorapatite can be formed.
What is the mode of action of CPP-ACP?
Calcium is intact with a CPP and is able to penetrate deep into the caries lesion and release calcium for remin due to acidity produced by cariogenic bacteria
What is a good way to change the ecology of biofilm?
Chlorhexidine mouth rinse.
What are the three steps to re-establish a healthy oral health environment?
- Change the ecology of the biofilm
- Improve the saliva
- Remove cause and re-establish new biofilm
Who is involved in treatment planning?
Patient and dentist work collectively to develop a plan that satisfies the patient’s needs.
What do we need to explain to a patient?
- Their oral health status
- Waht will happen if nothing is done
- Treatment options
- What patient is required to do
- IF they want to proceed
What info do we need for treatment planning?
Full examination, with all histories and potential extra test like bitewing radiographs
What are the basic principles of Soft tissue health & preventative treatment?
Focus on hygiene instructions and removal of plaque and stains. Could potentially make a diet diary
What are the general principles of GV Black operative dentistry?
The GV Black Principles are essentially that a larger cavity is able to provide enough mechanical retention in order to keep an amalgam feeling intact. It is taught internationally and patients still walk around with GV Black Style restorations.
What are the steps of GV black cavity preparation?
- Access
- Outline
- Resistance
- Retention form
- Convenience Form
- Remove the rest of the carious dentine
- Cavity cleaning
Why is GV not as advantageous?
Because it requires a removal of a large amount of healthy structure thus it is not ideal for a long term prognosis of the tooth.
What is the difference between GV Black and MI philosophies?
In GV Black – we restore all lesions, in MI – we can arrest some.
Which GV Black operative concepts are still apply to modern dentistry?
The concept of restoration, use of certain materials like amalgams, the shape of the cavity used for mechanical retention, removal of cariogenic bacteria, instrumentation.
What is the significance of the infected dentine?
The infected dentine is the dentine that has a colony of bacteria residing in it.
What is the significance of MI philosophy that relates to the histology of the tooth?
MI philosophy indicates that maximum amount of tooth structure and affected dentine can remain intact IF infected dentine is removed and affected dentine is sealed.
What are some of the cavity terminology?
a. Cavosurface angle
b. Wall
c. Pulpal wall
d. Axial wall
e. Gingival wall
f. Line angle

What is the Class I cavity in the GV Black principal?
They are cavities beginning in pit and fissures – all fissure system needs to be removed.
What is the Class II cavity in the GV Black Principal?
Cavities in the proximal surfaces of the premolars and molars
What is the Class III cavity in the GV Black Principals?
Cavities in the proximal surfaces of premolars and molars (MO, DO, MOD)
What is the Cass IV cavity in the GV Black Principals?
Cavities in the proximal surfaces of incisors and canines involving the incisal edge
What is the Class V cavity in the GV Black Principals?
Cavities in the gingival third of the labial, buccal and lingual surfaces
What is Site 1?
Pits, fissures and enamel defects on occlusal surfaces of posterior teeth and cingulum and other smooth surfaces of the interiors
What is Site 2?
Approximal surfaces in relation to areas in contact with adjacent teeth
What is Site 3?
The cervical one-third of the crown, or following gingival recession, the exposed root
What are the 5 different sizes of caries?
Size 0 – can remineralise
Size 1 – minimal cavitation
Size 2 – moderate involvement of dentine
Size 3 – Lesion large
Size 4 – Extensive caries or bulk loss of tooth structure
What type of restoration are there?
Direct and indirect
What are the desired properties of resin composites ?
- Aesthetics
- Handling properties
- Biocompatibility
- Protect tooth bioactive
- Function
- Longevity
- Radiopacity
Where would we use resin composites?
- Aesthetics
- Toothstructure to bond
- Strengthen tooth structure
- Blood and moisture can be controlled
- Where occlusal loads are not sever
What is the basic composition of composites?
Synthetic Organic resin (which is a viscous liquid) that is bonded to inorganic filler particles with a silane coupling agent made to set or light cured.
What is organic matrix of resin out of?
Bis-GMA – very viscous thus needs to me mixed in with diluters like TEGDMA
What is the inorganic filler?
They are particles that binded to organic resin matrix by coupling agent (silane). Could be crushed glass, quartz, ceramic, amorphous silica or hybrid
What are the initiators and inhibitors?
They are chemicals that regulate the setting of the resin – working time mediators
What particles may give resin radiopacity?
Barium or Strontium
What is a polymerisation reaction?
When monomers use their structural units to form polymers – causes shrinkage.
How can we classify resin composites?
- Composition
- Method of cure
- Handling properties
What happens when filler weight is increased?
The physical properties of the material increases. May cause chipping during polishing and stain uptake.
What are the methods of cure for resin composites?
- 2-paste system
- Light cure – wavelength is perfect (blue light)
What are the classification based on handling properties?
- Flowable - can be placed in areas of less stress
- Packable composites
- Bulk Fill Composites
What happens to unpolarised resin?
It may damage the pulp because it is toxic thus it needs to be polymerised. Becomes a problem in wet environment or when placed in large increment.
What is the C-factor?
Cavity configuration factor. Number of bonded surfaces/free surfaces. The higher the C-factor the higher the shrinkage stress. Shrinkage not good.
What are the steps to bonding resin to enamel?
- Prophylaxis
- Acid treatment – for microporosities – increase of surface area for interlocking in the area and create a macromechenical bond – increase of surface area by 2000 times
- Wash and dry – stop the demin process and remove moisture
- Fluid (unfiled) resin – flow into microporosities to create resin tags – chemical bonding
- Unfilled resin polymerised
- Composite resin placed
- Polymerised
What are the steps to bonding to dentine?
Etching – this will expose collagen – may cause pulpal fluid to flow up which can compromise the bond – etch for a little less
Use a primer – wet or dry – dry: collagen is collapsed which rehydrated – wet: small amount of water remains – creation of hybrid zone
Unfilled resin
Polymerise
Filled resin
Polymerise
What are the gold standard adhesive system?
3-step etch system – 3rd generation system
What are the 2 approached to adhesive systems?
- Total etch - separate etching
- Self etch
How do GIC bond?
They bond chemically throguh ion exchange and can exchange ions with tooth and oral environment.
What is the basic make up of GIC?
- FLuoro-Alumino-Silicate Glass
- Barium or strontium – for radiopacity
- Poly Alkenoic acid
Why don’t you mix products from different manufacturers for liner GIC?
Different roducts have different components that may not create the desires clinical outcome
Why is capsule good for GIC?
Highly manufactured and little possibility of human error in mixing
How does a GIC capsule look like?
Powder and liquid divided by a membrane
How does acid-base reaction occurs in GIC?
- Polyacid attacks glass particles – calcium, strontium and fluoride are released
- Precipitation of salts occurs = gelatation and gathering occurs
- Maturation phase = acid/base reaction continues for a few days
Why do we need to protect the GIC during the maturation phase?
GIC are vulnerable to take-up of extra water or water loss. This may create a loss in physical properties. This can be avoided by layering of unfilled resin of G-coat over the top.
What are the main disadvantages of the GIC?
- Not as strong
- Aesthetics are not as good
- Take-up/lose water – xerostomia
- More susceptible for acid breakdown
- More susceptible to abrasion damage
What is the advantage of RMGIC?
- Better aesthetics
- Harder
- Auto and light cured
What are the advantages of GIC?
- More biocompatibility – compatibility with soft tissues and pulp response
- Release fluoride / create fluoride reservoir
How does GIC bond?
- GIC bonds through a chemical reaction
- Polyacrylic acids dissolves the crystalline structure
- The minerals released are able to interact with minerals in the GIC
- The result is ion exchange and creation of the zone of adhesion between the material and the tooth surface
What are the powder to liquid ration of the GIC types?
Type I – Luting GIC – 1-1.5:1 – used for indirect restorations
Type II – Restorative GIC – 3:1
Type III – Lining or Base GIC – 1-3:1
Why are GIC not great long term?
They are just not hard enough
What are GIC good for?
- Shot term restoration for remin
- Puttin other material on top e.g. composite
What are the steps of placing resin of top of GIC base?
- Cute the GIC and create space for resin
- Etch
- Put unfilled resin on the GIC and etch enamel – GIC has irregular shape = micro-mechanical bonding
- Cure
- Place resin
- Cure
What is a closed sandwich technique?
When GIC if covered around with another material
What is an open sandwich technique?
When GIC is exposed outside the tooth – to the oral environment
What are the steps in applying GIC?
- Clean the surfaces with pumice and water – for better ion exchange
- Use Polyacrylic acid – depending on % - to remove the smear layer and exposure the clean tooth surface for ionic exchange
- Wash it off – stop the reaction
- Dry but do not desiccate – stop flow of dentinal fluid
- Place GIC
- Protect in the moisture sensitive phase
What is amalgam?
They are mercury and combination of another material
How does amalgam set?
When certain alloys are processed like silver or tin, they can harden when mixed with liquid mercury
How can we classify amalgams?
- Particle Shape – handling characteristics
- Composition - properties
What are the three particle shapes of amalgam?
- Lathe cut – long – sausage like
- Spherical - looks like a sphere
- Admixed amalgams
What are the classification of amalgam by composition?
- Convetional or Low copper
- High-Copper amalgam
- Zinc content
What is the advantage of high copper amalgams?
High copper amalgam are able to eliminate particles in the Gamma 2 phase during the maturation of amalgam making it stronger and last longer.
What are the physical properties of amalgam?
- It has high compressive strength
- It has low tensile strength
- It is brittle
Why do amalgam may need liners & base?
Due to their thermal properties
What are the steps of amalgam placing?
- Remove caries or remove failed amalgam
- Consider depth of cavity – at least 2 mm into dentine
- Remove unsupported enamel
- Retention - macromechanical retention
- Liner/base
- Pack amalgam using a plugger – permite ect amalgam used in sim
- Burnish
- Carve using cuspal inclines
- Articulating paper and adjustment
- Polish 24 hours later
What proportion of caries occurs from the fissures?
90% -due to creation of ecological niche
What is the important thing about the enamel on the walls of the tooth fissures?
It is aprismatic enamel that is high mineralised
What are some of the techniques for caries diagnosis?
- Visual Examination – clean, dry, illuminate well and use the tip of the explorer
- Radiographs - just remember of superimposition, it is probably bigger than it is on radiographs
- DIAGNOdent - measuring reflected light – little to no florescence in clean, healthy teeth
What is a use of fissure sealants?
Where there is an elevated risk for the fissures to develop or progress in caries. Fissure sealants are able to change the morphology of the fissures to make it easier to clean and to eliminate that ecological niche.
They can also be used to seal the bacteria and cut them from needed nutrients to grow – this may need close recalls!
What are the two types of fissures sealant on the market?
- Resin based sealants – better retention
- GIC/RMGIC - not as good retention
What are the factors that effect fissure sealant retention?
- Material & placement technique
- Tooth surface – fissure anatomy, degree of surface mineralisation, debris in the fissure
- Occlusal load – NO CUSPAL INCLINES
What are the steps of resin based fissure sealant placement?
- Clean surface – remove debris
- Etch (orthophosphoric acid 37%)
- Wash - stop reaction
- Dry well – frosty appearance
- Flow in fissure – no bubbles
- Light cure it
- Check occlusion
What are the steps of GIC/RMGIC based fissure sealant placement?
- Clean surface – pumice
- Condition with polyacrylic acid
- Wash
- Dry - leave moist
- Place in fissure
- Apply protective coat
- Cure
- Check occlusion
What is enameloplasty?
It is a procedure, where micro-surgical burs are used to widen the fissure and remove the aprismatic layer for better bonding of the fissure sealant
What defines the dimensions of the restoration?
It is defined by shape and size of the carious lesion
What is the technique 1?
RMGIC (1:1 on the Dentine) with CR o Amalgam over the top – use with rubber dam
What is the technique 2?
RMGIC (1:2 on the Dentine and Enamel) with CR or Amalgam – use with worst isolation
What is the technique 3?
Use RMGIC as base – cut back and use CR or Amalgam – use for super deep cavities
What are some of causes of damage to the dentine and pulp?
- Caries - through bacterial acids, toxins and enzymes
- Micro-leakage – due to unsealed margins – could cause sensitivity and recurrent caries – seal so bacteria can go into a dormant state
- Mechanical damage – fracture, cavity preparation, cracked cusps, dehydration
- Thermal damage – during cavity preparation friction, polishing, absence of insulation (base & liner)
- Chemical damage – Hema & Tegma & other acids
Why is gathering information is critical in terms of restorative work?
It presents possible aetiologies and guides us towards final aetiology
What type of questions can we ask the patient about their pain?
- Location
- Commencement of pain
- Character of pain
- Frequency
- Duration
- Time
- Precipitation factors
- Other complains
What type of sensibility testing can be used for testing pulp vitality?
- Electric
- Cold
- Heat
- Transillumination
- Percussion
- Wedges test
- Radiographs
- Muscle & TMJ palpation
What s dentine hypersensitivity?
It is a sharp, short lasting pain that is caused by movement of fluid in the dentinal tubules causing irritation in the pulp
What theory are we using to describe dentine hyper sensitivity?
Hydrodynamic theory
Explain hydrodynamic theory.
Dentinal tubules contain an extension of the odontoblasts (odontoblastic process) in the part of the tubule that is proximal to the pulp. Around the odontoblastic process, coiled are small nerve extensions. The rest of the space inside a dentinal tubule is filled by dentinal fluid.
If the fluid is disturbed through heat, cold, dehydration and even touch and pressure, it causes the fluid to move which activates the pulpal nociceptros around the odontoblastic processes this cause an action potential and signals for pain.
What are the ways we can treat hypersensitivity?
- Block dentinal tubules – durafat has resin
- Block the nerve activity
- Remove the cause
What is reversible pulpitis?
It is a reversible irritation of the pulp
What is irreversible pulpitis?
It is an irreversible irritation of the pulp
What is pulpal necrosis?
It is when pulp is non-vital
What are some of the materials are used in pulp protection?
- Varnishes - copalite – used to block dentine tubules – bad longevity
- Liners - cover the dentine – placed under restorations – used for shallow cavity – CaOH cement (Life) - very alkaline - GIC line bond LC
- Bases - similar to liners but are thicker – use as dentine replacement – ZnPO4 cement is an example – Zinc Oxide-Eugenol is another example – GIC like the Fuji series
What is considered a true seal?
True seal is a seal created by GIC’s and RMGIC’s due to the fact that they able to chemically bond to both enamel and dentine unlike resin composites
What are the steps of placing the liner in a relatively small cavity? Why so?
- Prepare cavity
- Condition the cavity
- Mix Fuji Bond LC 1:1
- Apply
- Cure
- Etch the enamel
- Wash dry
- Use unfilled resin
- Cure
- Add filled resin
This will make sure that RMGIC is able to release fluoride and create a chemical bond with resin
What are the steps of placing a base in a relatively large cavity? Why so?
- Prepare cavity
- Condition the cavity
- Place a Fuji II material – larger amount for a larger cavity needed – advantage of being light curable
- Open enamel margins
- Etch
- Wash dry
- Use unfilled resin
- Cure
- Use filled resin
What is indirect pulp capping?
It is when a patient has a deep carious lesion with NO SIGNS OR SYMPTOMS OF IRREVERSIBLE PULPITIS.
Removal of all infected dentine is likely to result in pulp exposure.
What is direct pulp capping?
Pulp exposed but there are also no signs or symptoms of irreversible pulpitis
What are the original steps of indirect pulp capping?
- Removal of nearly all dentine
- Placing CaOH – to create an environment that will cause pulp to produce secondary dentine
- Place temporary restoration of Zinc Oxide-Eugenol
- Later - take X-ray and check for reparative dentine
- Remove the infected dentine and place a permanent restoration
(This is a two appointment method)
What are the steps for the current method of indirect pulp capping?
- Remove caries
- Place GIC/RMGIC to ARREST caries
- Leave or restore in the same appointment
What are clinical indications and considerations for indirect pulp capping?
- Pulpal status – no signs of irreversible pulpitis and apical pathosis
- Coronal Seal Ability
- Informed consent
What are the steps to direct pulp capping?
- Stop bleeding – sterile cotton pallet
- Apply CaOH on top of the exposure – causes sterile necrosis – creates calcific bridge
- GIC/RMGIC
- Restore
What are the aims of polishing?
- To restore function
- To restore and maintain gingival health
- To restore aesthetics
What are the aims of polishing wanting to achieve?
- Remove the access restorative material
- Create a suitable contour of the restoration
- Maintain contact areas with normal form
- Ensuring embrasures are spaced correctly
- Eliminate surface irregularities
- Producing a fine, smooth surface
Why don’t we advocate to polish the amalgam restoration less than 24 hours after placement?
Because amalgam would not reach it’s set, meaning it may chip away and create ecological niches for bacteria to thrive.
What are the steps to amalgam polishing?
- Treat the interproximal surface with caution!
- Gross reduction using slow speed green stones
- Controuring and smoothening using multi-fluted finishing burs
- Pumice - add powder and a bit of water
- Final finishing using rubber cups and points
What is the meaning of the red band on the burs?
It means that the burs are made out of a finer diamond and are suitable for polishing
What are soflex discs?
They are small discs with diamond incorporated – they vary in coarseness
What are the steps of polishing resin composites?
- Utilise existing tooth structure
- Gross reductions
- Contouring
- Refine the surface – use articulating paper, ask the patients for feedback
- Final polish using stone burs
- FInal glaze with unfilled resin WITHOUT HEMA
What are white stone burs?
They are single use burs impregnated with aluminium oxide. Used for final finish. Used without water. 10k-15k RPM with light intermittent pressure.
What are the basic principles of polishing GIC?
- After 24 hours only for chemical GICs
- GICs should be protected – g-coat or unfilled resin
- Follows steps for Resin Composite
Is caries a one way street?
NOPE. Even if we have early demin, we can actually remineralise the enamel by changing conditions in the oral cavity to supersaturated condition! We can do it all the way upto cavitation!
When can we remineralise the enamel?
- When the demin is exclusive to the enamel
- When there is affected dentine but no infected dentine
What happens during the pathogenesis of caries?
- Unsaturated conditions cause the initial demineralisation of enamel
- The initial demineralisation causes the increase in porosity of the enamel – the acid is able to penetrated deeper into the enamel
- The acid is able to reach the dentine – this creates affected dentine – further porosities increase occurs
- The amount of affected dentine increases by following the dentinal tubules – porosities increases further – BACTERIA CAN ENTER NOW
- Dentine becomes infected with bacteria – now we must remove the infected dentine surgically
- Porosity increases – the physical stress is able to cause cavitation by destroying the tooth structure
What does proximal caries depend on?
The location of the contact point – biofilm accumulates there and if the biofilm is cariogenic – demin over remin - result : caries
What is Caries Infiltration Technique?
It when viscous resin that is used interproximal to stop the spread of caries with no cavitation.
What are the steps of Caries Infiltration Technique?
- Isolate and spread the teeth with a wedge
- Place special etch
- Wash and dry (use ethanol for extra drying)
- Apply low viscosity resin wish special tool
- Use floss to remove excess
- Light cure from lingual and buccal surfaces
- Remove wedge and check with floss
When would you use a slot preparation?
When the marginal ridge has been compromised by caries.
When would you use a tunnel preparation?
When the marginal ridge was not compromised by caries
When would you do an internal tunnel prep?
When there is no cavitation
When would you do an external tunnel prep?
When there is cavitation
What are the steps to slot preparation?
- Shade selection
- Rubber dam
- Use proximal surface protection for the adjacent tooth – use tofflemeir or sectional matrix
- Evaluate site and extent of carious lesion, contact point with adjacent tooth is the guide
- Acess down through marginal ridge – leave the marginal ridge intact
- Bucco-Lingual widening IF caries is resent there
- Clean the DEJ and remove infected dentine
- Think about the restorative material in regards to unsupported enamel left!
- Finalise cavity outline
- Matrix selection – toffeliemire or sectional matrix
- Burnish Matrix Band
- Use a wedge
- Place a liner
- Place resin
- Check the surface with an explorer
- Polish
What is the disadvantage with matrix band when using composite?
With deep caries, use of toffelmire created a lot of overhangs.
What is the rational behind the tunnel prep?
Basically, if the carriers to do not extend far enough to compromise marginal ridge
What are the steps to tunnel prep?
- Access caries, 2mm deep, avoid marginal ridge
- Create a triangular acess cavity for right angulation
- Tilt the bur
- Remove the caries, clean DEJ
- Apply matrix band and wedge
- Restore with GIC – because of dentine replacement
- FInish occlusal surface
- Protect the surface
- Allow GIC to set
What are methods of caries detection of site 2 anterior lesions?
- Clinical examination
- Transillumination using overhead light and fibre-optic
What are the steps to site 2 anterior restoration?
- Shade selection
- Check occlusion
- Isolation using rubber dam
- Acess using high speed bur – first near marginal ridge and than through it and remove the enamel wall
- Clean DEJ and remove infected dentine with slow speed bur – size 2 round bur is pretty good for this! (keep as much enamel as possible, keep the incisal edge if possible, only remove jagged enamel edges
- Restoration
What are the steps to restoring a site 2 anterior post cavity preparation?
- Condition dentine + wash & dry – 20% polyacrylic acid for 10 seconds – do not desicate
- Liner RMGIC + LC (cover all dentine) - use celluloid strip – c shape facing the gums (taper towards the root) - place a wedge too!!
- Etch enamel + wash & dry
- Adhesive over enamel and dentine + LC
- Resin Composite (placed in increments) + LC
- Polish
- Remove RD
- Check occlusion
- Final polish
- Check with floss – can use the 3-M finishing strip
How do we assess the fractures?
- Tissue exposed – enamel only, enamel and dentine or exposed pulp
- Surfaces involved
- Check occlusion
How do fracture arise and what is the problem with that?
Usually – traumatic episodes. It is problematic becaus
What is an uncomplicated fracture?
It is a fracture with no pulp exposure
What is a bevel?
It is a process of cutting the enamel, at 45%, to increase the surface area of enamel for bonding. This could be created with high speed diamond burs.. Make sure that the transition is smooth. Pls do both palatal and labial.
What is scalloping?
It is a process of cutting the enamel – similar to bevelling, accept the line is more wave like. This is made to camouflage the transition n=between material and tooth structure
What are some of the options for bonding of a fracture restorations?
- Direct bonding of CR to dentine and enamel
- CR with RMGIC liner on dentine
What are the steps of fracture restoration using a direct bond method?
- Condition the dentine
- RMGIC liner on dentine
- Etch enamel
- Adhesive - unfilled resin
- Resin composite
How do we assess the final outcome of the restoration?
- Remove rubber dam
- Check occlusion
- Check interproximal contacts and remove any excess material
- View restoration from many angles using direct and indirect vision
- FInal polishing
- Check patient satisfaction
What are the three main types of tooth wear?
- Abrasion - 3 body
- Attrition - 2 body
- Erosion - chemically mediated
What is erosion?
Erosion is loss of dental hard tissue by chemical process not involving bacteria
What are the steps of erosion?
- Acid is introduced to the oral cavity
- Acid displaces the saliva covering the tooth
- Acid dissolves the biofilm and pellicle
- Acid makes contact with enamel
- Acid cause dissociation of hydroxyapatite
- This result in removal of enamel and scalloping
- This continues, and speeds up when it comes to dentine because dentine is composed of less hydroxyapatite, thus dissociates more easily
- Because of the open system, the dissolved hydroxyapatite is removed thus no remin can occur
What are the steps for clinical approach to MI management of erosion?
- Identify if erosion is present
- Chek the sensitivity of the tooth
- CHeck for presence of staining
- CHeck for previous restoration
- Perform a scratch test
- Create a basic erosive wear examination to determine the erosive wear index
What are the two main sources of acid in erosion?
- Intrinsic - relating to stomach
- Extrinsic - relating to diet
What are some things that drive erosion?
- Amount of acid
- Type of acid
- For how long the teeth were exposed to the acid
What are some of the things the counter act erosion?
- Maturity of tooth
- Saliva
- Biofilm
What is the pattern of erosion relating to intrinsic sources?
- Upper posteriors are affected first
- Diffuses and affects the upper anterior next
What is the pattern of erosion relating to extrinsic sources?
- Occlusal of lower affected first
- Palatal of upper anterior
What is the only real way to stop erosion?
It is to stop acid attacks. Other ways are:
- Re-establish biofilm
- Neutralise the acid
- Potentially use remineralising solutions
- Use a different method of fluid consumption
- Protective covering over teeth
What is abrasion?
Abrasion is wear that results when exogenous material is forced over tooth surface
What is a non-carious cervical lesion?
It is a notched lesion, that is created by both abrasion and erosion
What is the steps of MI treatment for abrasion?
- Identify the cause
- Educate the patient
- Provide restorations if needed
What is attrition?
Attrition is wear that occurs when microfine fragments of enamel prism get caught between opposing tooth surfaces
What are the 2 potential diagnosis to site 3 lesions?
- Non-carious cervical lesion
- Carious cervical lesion
What is abfraction?
Abfraction is the development of ‘wedge-shaped’ lesion from flexing of the tooth under load
What are the steps to management of site 3 lesions?
- Identify aetiology
- Determine if process is active or historic
- Tret underlying aetiology or have a plan for this and start implementation
- Determine need for restoration
What does the restoration method of site 3 lesions depend on?
- Margins and surfaces
- Other associated factors: aesthetics
- Cavity depth
What are the steps to restoring an erosion lesion cavity that is just in the enamel?
- Etch with 37% orthophosphoric acid for 20 seconds
- Wash and dry
- Bonding agent
- Light cure
- Composite resin
- Light cure
What are the steps to restoring a site 3 lesions with enamel margins, that extends into the dentine?
- Condition with polyacrylic acid
- Use liner
- Etch enamel
- Use adhesive bonding agent
- Use composite resin
What are the steps to restoring a site 3 lesion with enamel margin coronally, dentinal margin gingivally. Depth into dentine?
- Condition enamel & dentine
- Use Fuji bond LC – 2:1 over the entire lesion
- Composite resin
What are the characteristics of root caries?
- Often follows gingival recession
- Often starts over a large area of exposed root
- Is circumferential
- Most often seen in older people and those with dry mouth
- Can spread coronally and undermine enamel
What is a complex restoration?
It is a complex restoration when:
- A large amounts of tooth structure are missing and need to be replaced
- When tooth structure is weak and needs protection
- When more than the conventional form of retention is required
What are symptoms of cracked cusp?
- Sudden pain when chewing
- Sensetivity to cold or hot
What is the purpose of cusp capping?
To strengthen weakened tooth structure and protect and preserve the remaining tooth structure
What are indication for cusp capping?
- Undermined cusp with caries removal
- Cracked cusp
Which cusps are considered at high risk of fracturing?
High cusps with small amount of base supporting them because the load propagates to the base of the restoration.
What are the steps to treating an incomplete tooth fracture?
- Remove the existing restoration
- Reduce the portion of the weakened cusp
- Place the restorative material and the cusp
What is the purpose of cusp replacement?
Replace missing tooth structure
What is the indications of cusp replacement?
Lost cusp
What are some of the options to create extra retention for amalgam restorations?
- Grooves/slots
- Pins
- Bonded amalgams
What are the rules in placing a pin?
- Place in dentine
- Pin hole parallel to external contour of the tooth
- 1 pin per cusp
- Must not be too high
- Must have access to condense amalgam around pin
How many mms of amalgam need to cover the pin?
Ideally 2 mm of amalgam
What are the steps to systematic carving?
- Ensure margins are sealed
- Commence carving occlusal aspects whilst matrix band is in place
- When suitable remove wedge and carefully remove matrix band
- Check interproximal surface of excess and remove if required
- Marginal ridge height and contour
- External cusp contour
- Cusp height
- Finish occlusal anatomy
- Burnish