Give some reasons why you would not extract a primary tooth?
- loss of space - malocclusion
- mastication
- speech
- aesthetics
- avoidance of GA
Give some differences between the pulp morphology of primary teeth compared to permmanent teeth:
- increased number of accessory canals, foramina and porosity in pulpal floors of primary teeth
- primary root canals are more ribbon like
- fine, filamentous pulp system
- more difficult canal debridement
- complete extirpation of pulp remnants almost impossible –> increased potential of root perforation
- root canal opening is several mm coronal to the radiographic apex
What are some contraindications of pulp therapy?
- tooth is unrestorable in the long term (not enough hard tissue left for restoration)
- Pt is uncooperative
- medically compromised
- orthodontic extractions
What pulp therapy options are there for vital priamry teeth?
- pulp capping - when pulp is exposed or nearly exposed and hard setting calcium hydroxide is placed to protect the pulp and encourage tertiary dentine to be laid down
- pulpotomy (pulp amputation)
- desensitising pulp therapy
What is a pulpotomy?
Involves removing the diseased coronal portion of pulp only, and applying medicaments to the remaining pulp tissue, thus allowing the tooth to continue functioning
- has a much greater success rate than pulp capping in primary molars
List some contraindications of a pulpotomy:
- abscess - infected or inflamed radicular pulp
- excessive bleeding upon access to pulp chamber
- no bleeding upon access to pulp chamber - indicates pulp is not vital
- needs to be a fine balance and have some bleeding that can be stopped
Name the medicaments used in pulp therapy:
- formocresol
- ferric sulphate
- gluteraldehyde
- calcium hydroxide (non-setting)
What are the active ingredients within formocresol?
How does it work?
Which guidelines state ir should no longer be used in conjunction with pulp therapy and why?
Active ingredients: tricesol (antiseptic) and formalin (tissue fixative)
- acts by binding with bacterial pulp tissue proteins, tissue fixed i.e. rendered inert and resistant to breakdown by bacterial enzymes
IARC 2004 - mutagenic and carcinogenic properties shown in animal studies
- wide distribution of the material in organs such as liver, kidneys etc due to its quick absorption in animal studies
- local tissue damage if formocresol becomes extruded through apical foramen possibly resulting in damage to permanent tooth germ
No evidence in human studies for any of these points!
How would you use formocresol?
- always use as small an amount as possible - make sure cotton pledget or paper point is well blotted
- isolation of the tooth invilved is important (dental dam)
- well sealed restoration margins to prevent leakage
Describe ferric sulphate:
- excellent haemostatic agent
- emerging as an alternative to formocresol
- not a fixative agent
- antimicrobial properties unknown
- applied to pulp stumps - 15% for 15 seconds
Give some information regarding gluteraldehyde:
- aqueous solution (2-4%)
- like formocresol, powerful fixative agent
- recently some toxic effects discovered
- shown to be fairly ineffective when compared to formocresol
- lack of research on material, which concentrations to use etc
- unlikely to be used as a common substitute
Describe calcium hydroside as a medicament:
- previously ruled out as a medicament because of internal resorption
- recent studies have shown equal efficacy with formocresol
- no toxic side effects known
- encourages new dentine formation from pulp
- often a ‘dentine bridge’ is formed
- remaining pulp tissue now has an effective barrier against bacterial invasion
- calcium hydroxide works by allowing healing within the pulp rather than ‘fixing’ the tissue
List the key points of:
a) Formocresol
b) Ferric Sulphate
c) Gluteraldehyde
d) Calcium Hydroxide
Formocresol - very efficient tissue fixative, recent concerns regarding safety - seek alternative
Ferric sulphate - a promising sub, although not as effective - works as a haemostatic agent, may have bactericidal properties?
Gluteraldehyde - works in same way as formocresol, not as effective, some toxicity reported, research needed, probably not a contender
Calcium Hydroxide - works by promoting new dentine formation, protecting pulp and allowing to heal –> promising
List the clinical steps involved in a pulpotomy:
- LA, isolate with dental dam
- Outline form to access caries - remove all caries prior to accessing pulp chamber
- Large access cavity - need ot be able to access all pulp horns - remove entire roof with stainless steel bur taking care not to damage floor of pulp chamber
- Remove contents with an excavator or large stainless steel bur - once pulp exposed, do not use 3 in 1 - risk of emphysema
- Irrigation with saline then light pressure from cottom wool pledget - aim to control bleeding
- Apply medicament of choice to pulp stumps using cotton pledgets or applicators for correct time (formocresol 4-5 mins, ferric sulphate 15 secs), repeat if necessary once more.
- Assess amount of bleeding - if well controlled, carry on to next step. If uncontrolled, may need to follow desensitising pulp therapy or pulpectomy procedure
- Restore tooth, usually with layer of hard setting calcium hydroxide on base, then zinc oxide eugenol, then place permanent restoration (stainless steel crown in posterior tooth)
What is the aim of desensitising pulp therapy?
When is this indicated?
- used to reduce pulpal inflammation and/or symptoms in order to facilitate subsequent pulpotomy or pulpectomy
Indications:
- carious pulp exposure but no signs or symptoms, or loss of vitality
- hyperaemic pulp during attempted pupotomy
- hyperalgesic pulp
Describe the technique of desensitising pulp therapy:
- open and gain access to pulp chamber (same as pulpotomy)
- place a cotton pledget with ledermix (steroidal antibiotic paste) directly over the exposure site
- place a well sealed temp dressing
- review in 2 weeks, proceed with pulpotomy or pulpectomy
What is a pulpectomy and how does it differ to a pulpotomy?
What are the 2 phases of a pulpectomy?
Pulpectomy aims to remove infected, necrotic tissue to obturate root canal
- differs to pulp amputation as the aim is not to preserve viable tissue but to remove necrotic tissue and obturate canals
Phase 1 - Canal Debridement
Phase 2 - Obturation
Can be dine in one single visit or over 2 if excessive bleeding, abscess etc.
What differences are there when carrying out a pulpectomy compared to a RCT in permanent teeth?
- apical foramina may be wider than permanent tooth (depending on stage of development) so damage to permanent tooth germ could easily happen
- root canals of primary teeth more ribbon shaped and harder to instrument
- root canal walls of primary teeth are very thin, therefore prone to perforation
- roots of primary teeth resorb, so material used must also be resporbable at a comparative rate
Describe phase 1 of a pulpectomy:
Phase 1 - Canal Debridement
- LA
- outline form like that of pulp amputation
- necrotic tissue removed from pulp chamber with excavator (should be little or no bleeding)
- irrigation with sodium hypochlorite solution
- canal instrumentation (small files, clean one each time)
- files must be kept short of apex to keep permanent tooth germ intact
- gently file canal walls, removing debris then irrigating
- dry canals with paper points or cotton pledgets
- either place a temp dressing (kalzinol) over an antimicrobial paste (ledermix) then review in 7-10 days or proceed to phase 2
Describe phase 2 of a pulpectomy:
Phase 2 - Obturation
- remove temp dressing and cotton pledget (if in place)
irrigate and dry canals once more
- place root filler material of choice (resorbable material) into root canals using instruments of cotton wool
- take care not to go near apex as no material should go through apical foramen
- most common material - zinc oxide and eugenol, can use nonsetting calcium hydroxide
- should be packed densely while taking care not to extrude through apical foramen, although ZnO/Eug and Ca OH fairly benign to tissues
- permanent restoration as with pulpotomy
What is the review period for pulp therapy in primary teeth?
- whether procedure was pulp amputation (vital tooth) or pulpectomy (non-vital), the tooth should be reviewed at 6 monthly intervals
- follow up radiographs should be taken at yearly intervals
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Restorative Management of Primary Dentition19
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Stainless Steel Crowns and Anterior Restorations18
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Pulp Therapy21
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Primary Extractions11
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Child Development, Communication and Management14
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Child Protection15
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Childhood Diseases9
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Disorders of Tooth Formation19
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Dental Trauma16
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Dental Care for Special Needs Children19
