Pulp protection and vital pulp therapy Flashcards
ILO 8.5b: have knowledge of the form and function of the teeth and associated structures, and the environment, in health and disease
what is the function of the dental pulp?
6
- nutrition - blood vessels
- sensory - nerve endings
- proprioception - protects from harm
- dentin formation - odontoblasts
- defence - inflammatory response and reparative dentine
- root formation and development
what cells are in the dental pulp?
- fibroblasts (collagen)
- odontoblasts (dentine)
- histiocytes
- macrophages
- granulocytes
- mast cells
- plasma cells
- blood vessels
- nerves (plexus of Raschow)
9
what types of nerves are present in the plexus of Raschow?
- myelinated (A-fibres) - superficial, fast conduction speed, low stimulation threshold
- unmyelinated (C-fibres) - deeper, lower conduction speed, higher excitation threshold
what nerve do the sensory fibres in the pulp arise from? what structure do they go through?
trigeminal nerve CN5 mandibular branch through the apical foramen to root of tooth
what are the different types of pulpal diagnosis?
6
- normal pulp
- reversible pulpitis
- irreversible pulpitis
- pulp necrosis / non vital
- previously treated tooth
- previously initiated tooth
what is the aetiology of pulp disease?
9
- caries - reversible/irreversible
- cracks - bacteria can enter
- trauma - can expose the pulp
- iatrogenic - from dentist
- attrition - exposes pulp
- restorations - secondary caries
- periodontal disease
- aggressive scaling
- orthodontic treatment
describe the journery of how caries can cause pulp necrosis
- caries enters enamel
- caries enters the dentine - significant pain
- caries enters the pulp - pulp becomes inflammed
- pulp becomes damaged and necrotic, infecting surrounding bone tissue
what is the difference between infected, affected and sound dentine?
- infected dentine is the outermost layer and irreversibly damaged - soft and can be excavated
- affected dentine is the middle layer and has been demineralised but not infected - firm and resistant to excavation, less discolouration
- sound dentine is the deepest layer and has not been affected by bacteria - hard, strong and healthy
what are the advantages to a dental rubber dam?
- asceptic technique - decreases possibility of further bacterial contamination from saliva
- retraction of soft tissues
- protection of soft tissues
- airway protection
- saves time
what would be used to disinfect a cavity?
2
- sodium hypochlorite (NaOCl) - used in RCT, cavities and exposed pulp
- chlorhexidine (CHX) - used when no pulp is exposed
give examples of cavity liners and bases
7
- glass ionomer cement
- resin modified glass ionomer (vitrebond)
- zinc phosphate
- zinc oxide eugenol (ZOE)
- light cured calcium hydroxide (theracal)
- non-setting calcium hydroxide (dycal)
- calcium silicate cements (MTA/biodentine/BC putty)
last 2 used for vital pulp capping/exposed pulp = vital pulp therapy
how does non-setting calcium hydroxide (dycal) work? what are disadvantages with it?
- antimicrobial
- dissociates into OH- and Ca2- ions which create an alkaline environment, not favourable for bacteria
- used for vital pulp therapy - indirect pulp capping
- highly soluble, resulting in softening of liner so material may be lost and poorly sealed
- formation of poor quality dentine bridge
what are the uses of calcium silicate cements?
5
- direct and indirect pulp capping
- pulpoptomies
- root canal filling material
- perforations repair
- regenerative endodontic procedures
what are the similarities and differences between biodentine and mineral trioxide aggregate (MTA) - calcium silicate cements?
similarities
* antimicrobial
* bioinductive and osteoinductive
* non-cytotoxic
* provides hermetic seal
differences
* biodentine offers no discolouration, MTA has crown discolouration
* biodentine has a radio-opacity similar/less than dentine, MTA has a radio-opacity higher than dentine
* biodentine used in crowns, MTA used in root canals
describe what is shown in this picture
- caries has been removed to the soft dentine
- soft (infected), firm (affected) and hard (sound) dentine remain
- aims to avoid exposure of the pulp
- axial walls should always be free from caries, but can be left on floor
selective caries removal
describe what is shown in this picture
- caries has been removed up to the firm (affected) dentine so all soft (infected) dentine has been removed
- firm and hard (sound) dentine have been left to avoid further removal of tooth structure and exposing the pulp
- axial walls should always be free from caries, but can be left on floor
selective caries removal
describe the one stage technique to remove caries
- remove caries to soft or firm caries
- apply calcium hydroxide or calcium silicate
- restore immediately
describe the stepwise technique to remove caries
- remove soft caries
- place calcium hydroxide or calcium silicate
- temporise with GIC
- after 6-12 months, later remove firm caries
- restore
what are the non-selective (complete) caries removal options with the pulp exposure?
- no pulp exposure - indirect pulp capping
- pulp exposure (VPT) - direct pulp capping, partial pulpotomy, complete pulpotomy
when is an indirect pulp capping used and how is it carried out?
- indicated in reversible pulpitis/traumatic exposure
- used when pulp is not exposed but can see shaddow of pulp
- apply calcium silicate (biodentine) or calcium hydroxide (teracal)
- final restoration immediately
when is direct pulp capping used and how is it carried out?
- indicated in pulp exposure
- disinfect and achieve haemostasis with sodium hypochlorite
- apply calcium silicate (biodentine or bioceramic putty)
- seal with resin modified glass ionomer or glass ionomer
- then place restoration
when is a partial pulpotomy used and how is it carried out?
- indicated in irreversible pulpitis / traumatic exposure
- remove 1-3mm of coronal pulp tissues
- disinfect and achieve haemostasis with sodium hypochlorite
- apply biomaterial layer (BC putty)
- place restoration
when is a complete pulpotomy used and how is it carried out?
- indicated in pulp exposure
- complete removal of infalmmed pulp tissues and caries from cavity floor and axial wall
- disinfect and achieve haemostasis with sodium hypochlorite
- pulp should have no necrosis or discolouration
- apply calcium silicate (biodentine/BC butty)
- directly restore tooth
what factors affect the outcome of treatment?
6
- rubber dam
- disinfection
- haemostasis
- inspection of pulp tissues
- choice of biomaterial
- coronal restoration
