Managing the vital pulp in operative dentistry Flashcards
Primary role of pulp?
Development of the tooth
Role of the pulp throughout life?
Maintains important sensory/defensive/reparative functions throughout life
Benefits of pain from exposed dentine and pulp inflammation?
Alert to injury
avoidance of chewing while repair takes place (tertiary/peritubular dentine depositon)
Other than sensory role what do nerves in the pulp regulate?
Cellular activity and repair e.g. helps cellular system respond e.g. tertiary/peritubular deposition
Function of mechanoreception in the pulp?
Regulation of chewing forces
What problems surround mechanoreception in non-viable pulp?
No mechanoreception in non-viable pulp so can put more force on it allowing cracks to propagate and fracture - tooth becomes non-viable
List defensive functions of tubular fluid
Dentine is wet because dentinal tubules filled with fluid
Hydration/nutrition of dentine
Fluid outflow to dilute insults
Fluid thickening (ILA) to reduce entry irritants
Defensive functions of wet dentine?
Makes dentine more resilient and tough
Defensive functions of hydration/nutrition of dentine?
More resilient, less likely to crack
Defensive functions of fluid outflow to dilute insults?
Exposing dentinal tubules, plural fluid is always flowing to the surface this stops microbes getting into the pulp and dilutes any microbial toxins trying to get into pulp
Defensive functions of fluid thickening (IgA) to reduce entry irritants?
Accumulation of IgA in the tubules makes the fluid thicker and makes it harder for microorganisms making their way to the pulp
List cellular defences of the pulp
Odontoblasts –> making peritubular, tertiary
Inflammatory cells –> stops microorganisms getting into the pulp by mounting defences against them
How are injured pulps preserved?
Pulp capping, pulpotomy and root canal treatment
Goal of dental professional?
Prevent dental disease, pulp injury and breakdown.
Do as little harm as possible with our treatments so that you can preserve as many teeth with viable pulps
Consequences of pulp breakdown?
Pain Swelling Sepsis Distress Costly e.g. root canal treatment or protective coronal restoration
How are the consequences of pulp breakdown avoided?
Managing treatment early
In regards to the dentine and pulp, what is it important to remember when treating either tissue?
They are intimately related. Odontoblast line the pulp chamber underneath the dentine. If you expose dentine remember the vital structures are connected
What protects the healthy pulp?
Intact enamel
Sound investing periodontium
How can protective barrier of the pulp be broken down?
Caries - crown preperation
Dental procedure (iatrogenic)
Trauma
What makes the pulp vulnerable to injury?
Open tubules
The more tubules you open, the greater/lower potential fro pulp injury?
Greater
Shallower, narrower/deeper, wider preparation increases/decreases danger and risks direct pulp exposure because near the pulp chamber the tubules are further away/closer?
Deeper, wider
Increases
Closer
How much of the dentine must remain for the threats to pulp to be more serious?
0.5mm
Name 3 types of plural irritants
Physical - eating
Chemical - material used on dentine
Microbial - most serious
Describe early carious lesion?
Enamel breached, opening dentinal tubules
How vulnerable is the pulp in an early carious lesion?
Vulnerable but not greatly
Sensitivity of teeth with early carious lesion? Why?
Sensitive to hot/cold/sweet stimulation because dentinal tubules are open so there is fluid change up and down the tubes (hydrodynamic fluid movement) - stimulating A delta fibres
What type of pain is A delta fibre pain? Why?
Short sharp pain, nerve endings are sited peripherally in the pulp
List 4 was the pulp protects itself in early carious lesions
Pulp fluid outflow and thickening
Tubular sclerosis
Tertiary dentine deposiiton - reactionary
Mild, superficial inflammation
What condition of the pulp can early carious lesions cause?
Reversible pulpitis
How is reversible pulpitis characterised?
Transient shape pain from hot/cold/sweet
How is moderate lesions characterised?
Half dentine thickness, more tubules opened - more micro-organisms can reach the pulp
How vulnerable is the pulp in moderate lesions?
More microorganisms and toxins can reach the pulp to more vulnerable - minor (reversible) pulp inflammation
Describe the pain in moderate lesions? why?
Tooth sensitive to hot/cold/sweet stimulation due to hydrodynamic fluid movement or pulpits (A delta fibres)
As the process progresses - sprouting of a delta fibres (higher concentration) exaggerates the response -> central sensitisation occurs (allodynia) so when you stimulate previously inflamed tissue there is an exaggerated response
How does the pulp continue to protect itself during moderate lesions?
Pulp fluid outflow and thickening
Tubular sclerosis
tertiary dentine deposition = reactionary
Inflammation
Describe the state of the pulp in a moderate lesion?
Pulp irritated/inflamed (pulpits) but often reversible if caries removed and cavity sealed bacteria and fluid tight
How are advanced lesions characterised?
Depp caries - inner 1/4 dentine radiographically
How is extremely deep lesions characterised?
Radiographically into the pulp
3 consequences of caries advanced within 0.5mm of pulp?
Pulp in danger of microbial invasion
inflammation may change from reversible to irreversible
micro-organisms may overwhelm pulp
Pain during a deep carious lesion?
Tooth increasingly sensitive to hot/cold/sweet as it is deeper in the tooth = more peripheral and central sensitisation
Inflammation in deep lesions?
Inflammation spreads into core of the pulp - stimulates C fibres = lingering pain = irreversible pulpitis = spontaneous pain
Characeteristic that shows change from reversible to irreversible pulpitis?
Change from short sharp pain to spontaneous, lingering pain
3 ways to damage pulp during cavity preparation?
Cutting deeper than necessary
cutting wider than needed
overheating/desiccating dentien
What does preparation of cavity involve?
Cutting dentine with rotary tools, washing and drying to see what you’ve done
What problems can cutting deeper than necessary during cavity preparation involve?
Opening wider tubules
Cutting odontoblast processes
Direct pulp exposure (clip pulp horn)
What problems can cutting wider than needed during cavity preparation involve?
Open tubules
Risk of direct pulp exposure
Main point to remember during cavity preparation?
Manage caries in an orderly manner - periphery first, deep part only when ADJ is completely clear
Main cause of adverse reactions from dental materials?
Fluid and microbial leakage (leaky margins) around restorations
Benefits of lining cavities?
Protect the pulp from irritant filling material
Prevent thermal sensitivity after restoration
prevent microbial leakage around restoration and possible injury
Induce reactionary or reparative tertiary dentine formation
Disadvantages of lining cavities?
If cavity is small then there is no room for restorative material
What 2 lining materials are traditionally placed in deep cavities?
What are there function?
Calcium hydroxide cement Kills microorganisms in cavity (ph12) Promotes tertiary dentine deposition Calcium silicate cement Similar action
Why is calcium silicate cement used therapeutically?
Actively trying to encourage tertiary dentine deposition
What is the function of glass ionomer cement as a lining material?
Helps remineralise softened dentine (F- release)
Bonds with dentine and seals
What is the function of resin bonding agents as a lining material?
Impregnate and seal dentine surfaces ‘hybrid layer’
Can protect and seal exposed dentine surface ‘artificial enamel’ - mesh
Name 5 materials that can act as lining materials for cavities?
Calcium hydroxide cement Calcium silicate cement Glass ionomer cement Resin bonding agents overlying restoration
In regards to deep/extremely deep lesion in a symptom free tooth, the advancing front of a carious lesion consists of softened dentine with few micro-organisms and can be left provided…
Cavity periphery is made clean (hard dentine)
No soft centre for restoration to sink into (e.g. enough caries is removed)
Cavity margins sealed fluid and microbe tight
Describe how much caries you would remove if using the traditional approach on advanced caries?
Use your personal skills and best judgement to remove as much caries as you dare without exposing the pulp
Describe the traditional approach of restoring a tooth with advanced caries
Use personal skill and best judgement to remove as much caries as you dare without exposing pulp.
Apply setting calcium hydroxide cement to deep dentine to kill microorganism and promote tertiary dentine deposition
Seal the cavity tightly
What to do if you expose the pulp during excavation?
apply direct pulp cap of calcium hydroxide or calcium silicate cement to exposed pulp tissue or remove the pulp (pulpectomy)
Name the 2 contemporary approach of caries removal
Partial (selective) caries excavation
Stepwise caries excavation
Describe partial (selective) caries excavation
Excavate periphery (along ADJ) to hard dentine
Excavate plural floor to firm dentine - don’t have to remove all brown tissue - just so it looks and feels firm
Line cavity with calcium hydroxide or calcium silicate cement (with the expectation it will help kill micro-organisms and promote tertiary dentine)
Permanently restore and review
Describe stepwise caries excavation
Excavate periphery to hard dentine
Excavate plural floor to soft or firm dentine (but not as deep as partial)
Line cavity with calcium hydroxide or calcium silicate and seal
Re-enter after over 6 weeks for secondary excavation - at this point the caries is arrested so the tissue is a lot harder = easier to restore
Permanently restore
What is the purpose of the contemporary approach for excavation?
Avoid pulp exposure
How do you know you have exposed the pulp?
Blood
What to do if you expose the pulp?
Quickly isolate the tooth (rubber dam)
Clear all caries from periphery of cavity
Stop bleeding and clean site with bleach
Cover exposure with calcium hydroxide or calcium silicate cement to promote tertiary dentine repair and pulp survival (direct pulp cap)
Monitor for signs and symptoms of pulp breakdown
What to do if pulp breakdown occurs?
Root canal treatment
What is the main aim when you expose the pulp?
Keep all bacteria out of the pulp
Suggest an alternative to direct pulp caps
Superficial pulpotomy
How to do a superficial pulpotomy?
Places wound in clean place Cut back 1-2mm pulp with cooled high-speed Haemostasis with NaOCl Wound dressing (calcium silicate) Restore and monitor
