Endodontics of the traumatised immature incisor Flashcards
what is the definition of an immature permanent incisor?
> one where the apex can be considered to be open
what is the sequence of root growth from the crown to the apex of a tooth?
divergent > Parallell > convergent
what are the challenges of a non-vital immature tooth?
> Compromised crown root ratio
> Thin root dentine walls
> Lack of dentinal stop against which root canal materials can be condensed
what is the name of Endodontics which is carried out in a non vital immature tooth to close the root?
> apexification
what is apexification?
> RCT of these non vital teeth requires a root end closure technique to form a barrier at apex to enable a root filling to be condensed without going through apex
> old - Calcium hydroxide therapy to induce barrier
> new - Artificial plug (MTA)
what is the difference between apexification and apexogenesis?
> apexogenesis aim is to maintain vitality and allow continued root growth (vital pulpotomy)
what is the diagnostic pathways for loss of vitality?
> Signs + Symptoms
- Pain, swelling, sinus, TTP, mobility, colour change
> Radiographic examination
- Periapical radiolucency (PAP), arrest of root development
> Sensibility tests
- Negative
> Any doubt of loss of vitality - delay endo Rx
Review 3 mths
Better prognosis if no acute abscess
how is an emergency treatment for an acute abscess carried out?
> Ideally full extirpation of pulp and dress with non-setting Calcium Hydroxide paste
> But if acutely tender
- Prescription
- Arrange appt 24 – 48 hrs
- Sedative dressing – e.g. odontopaste
what are the aims of CH apexification?
> Creation of a calcific barrier across the root apex
> Allows obturation of canal
what is the method of CH apexification?
> Achieved by repeated dressing of non-setting Calcium hydroxide at 3-6 monthly intervals
> Once barrier achieved remainder of canal obturated with thermoplastic GP
> Average 9 months to form up to 3 years
what is the plug made out of?
> coarse osteocementum material
what is the success of CH Apexification?
> 90% apical closure
> 85% success at 5 years for adequate root filling
what are the disadvantages of CH apexification ?
> Multiple visits
> Lengthy treatment - may take up to 30 mths for barrier
> Difficult technique
> Position and quality of barrier unpredictable
> Discolouration
> increase brittleness (risk of cervical #)
> Expensive in terms
1. Clinical time
2. Parent’s time off work
3. Missed school
what is the clinical technique of creating an MTA barrier? (consent - interim root canal dressing)
> Consent
> Isolation
> Access cavity
> Widen cervical constriction (Gates Glidden)
> Extirpation of the pulp
> Estimation of full working length (1mm short of radiographic apex
.> Preparation of root canal, sterile water / 0.5% Milton
> irrigation (must avoid extrusion through apex)
> Needle loose and 2-3mm short of working length
> Dry the root canal
> Interim Root canal dressing (CH) +RMGI
is the access cavity in an immature tooth larger or smaller than a mature tooth?
> Triangular shaped access (apex towards gingival margin
> Larger than access cavity for mature tooth
what is important to remove in a MTA barrier prep?
> remove cervical constriction in the canal
what are the key points of canal preparation for MTA barrier? and what instruments are used?
> Straight line access
> May be up to no 140 file
> Ultrasonic activation or bristle brush
> Plugger
Bristle brush
Fine tip for placement of non setting Calcium Hydroxide (eg. typical, calasept, ultrascal)
what is the clinical technique for MTA barrier? (review - finish)
> Review in 1-2weeks
> Obturation when
- no clinical signs of PAP
- no radiographic signs of PAP or evidence of healing
> clean dry canal
> Fine tipped MTA carrier
> Ideally using microscope
> Plugger marker 2 mm short of WL
> Careful condensation until 4mm thickness
> Clean canal walls and access (MTA stains)
> Confirm placement with radiograph
> When set obturate (ProRoot
2nd visit reqd)
> Thermoplastic GP- diverging/parallel
Fibrepost
> check radiograph after RCT
> follow up 1 year
what are the properties of MTA?
> Hydrophilic
> 5 min working time, sets <4hrs
> pH 12.5
> Non-resorbable
> High biocompatibility
> Compressive strength = reinforced ZOE
=EBA
<amalgam
> Low leakage <Amalgam + IRM
what are the advantages of MTA?
> Small number of visits
> Biocompatible
> Low leakage
> Radioopaque
> Better success than CH technique
what are the disadvantages of MTA?
> Cost
> Discolouration with poor handling
> No reinforcement of canal
> Contributes to brittleness
how to we restore an immature root treated tooth?
> Where no bleaching GP removed to cemento enamel junction = Direct composite crown build up
> avoid conventional posts and crowns
> DT light post - can be considered
why would you avoid placement of a post and crown on an immature root treated tooth?
> Short root
> Leaves inadequate root filling
> Fragile canal walls
> High risk of root fracture
what is regenerative Endodontics technique?
> Aims to harness potential of stem cells at apical papilla
> Repopulation of root canal space by stem cells from apical papilla
> Cells similar to dental pulp progenitor cells
> Canal repopulated with vital tissue
> Produces further hard tissue of root
