Principles of treatment of diseases of the vital pulp Flashcards
Endodontics definition
Scientific/study
Endodontology definition
Therapeutic procedure
Interceptive endodontics
Pulp capping
Preventive endodontics
Good restorative and operative practice Maintenance of pulpal health Prevention of pulpal damage Minimising negative impact of therapeutic interventions on pulpal health 'keeping pulp alive'
Corrective RCT
Repeat RCT
Re-treatment
Vital pulp
Living tissue with blood supply
May or may not be innervated
Non-innervated tissue insensitive
Key-critical component of tooth and without it tooth is irreversibly compromised, with very negative effect on durability
Contrast between vitality and sensitivity
Vitality - blood supply
Sensitivity - nerve supply
Apical foramen
Opening at the apex of the root of a tooth, through which the nerve and blood vessels that supply the dental pulp pass
What does pulpal tissue contain
Blood supply Nutrients Immune factors Nerve supply Controls dentine fluid flow Important in mineralisation Essential for proper physiological functioning of dentine and enamel Proprioception - regulates max loads Resides inside pulp chamber that provides structural integrity to tooth
Preservation of pulp vitality - why?
To keep the tooth (avoid extraction) To avoid root-canal treatment To preserve structural integrity of tooth To maintain proprioception of pulp To minimise operative treatment -->To prolong durability of tooth
Consequences of loss of pulp vitality to the individual
Inflammation & infection of pulp and local and systemic consequences of this
Pain, in different grades and of unpredictable nature
Consequences of loss of pulp vitality to the tooth
- Necrotic pulp
- loss of proprioception
- breakdown of pulp into dentine: dark tooth
- need for RCT or XLA - RCT: significant loss of structural integrity
- Restoration of root filled tooth
Consequences of RCT: significant loss of structural integrity
Loss of roof of pulp chamber (mechanical prep)
Effects of RCT mechanical prep
-NaOCl - dissolution of superficial (canal wall) collagen - makes dentine more brittle
-EDTA - dissolution of superficial (canal wall) calciumHAP
-Effect of eugenol - makes dentine more brittle
Consequences of necrotic pulp
- loss of proprioception
- breakdown of pulp into dentine: dark tooth
- need for RCT or XLA
Consequences of restoration of root filled tooth
Always more compromised
At best = occlusal adhesive restoration
At worst= retained root that needs post-core and crown restoration
Durability and overall prognosis very poor
Why avoid extraction?
Loss of tooth
Functional and aesthetic problems
Avoid compromising other teeth
Avoid other treatment modalities with > morbidity and unpredictable outcomes
Why avoid RCT
To avoid irreversible and catastrophic structural degradation
To maintain proprioception
To avoid periapical and periradicular infection - with local and systemic complications
How compromised is a root-filled tooth?
Loss of roof of pulp chamber significantly reduces fracture strength
Direct relationship between amount of remaining tooth structure and ability to resist occlusal loads
Minimal access cavity in intact tooth reduces cuspal stiffness by 5%
Upper 6
4 canals, 3 roots
What makes a root-filled tooth different?
Compromised architecture
Changes in physical properties
Changes in loading
If lesion at bottom of root (periapical)
Do a sensitivity test
If asymptomatic, monitor
If symptomatic, RCT
Should do something about it
Reduction in fracture strength due to
Loss of structural integrity
Tubular sclerosis, secondary and reparative dentine
< in amount of mature collagen in dentine matrix
Eugenol > dentine microhardness
NOT due to < in moisture content
Darker tooth
Something wrong with pulpal tissue
Sensibility test - vital or non-vital
Then radiograph
Challenges to the pulp
Mechanical prep e.g. trauma, cavity prep
Thermal damage e.g. pulp testing, cavity prep
Chemical substances e.g. dietary acids, eugenol
Microorganisms e.g. caries, periodontal disease, cracks
Change in what temp can pulp not tolerate
5 degrees C
Factors affecting tooth
Bacterial biofilm Variable pH Constantly wet Changes in T Tooth-materials interactions
Environmental damage
Temp cycling Permanentlywet pH changes Functional loads Parafunctional loads
Total or partial caries removal?
A lot more pulpal exposures from total (50 vs 219)
No evidence of diff. restoration longevity
Insufficient evidence to determine whether diff. in signs and symptoms of PD between partial and total
Partial caries removal advantages
- Partial caries removal < incidence of pulpal exposure in symptomless, vital, carious primary as well as permanent teeth
- PCR technique shows clinical advantage over complete caries removal in management of dentinal caries
Reduces cavity size - preserve tooth structure
Effect of operative damage
Overheating Inappropriate cavity prep Over cutting during caries removal Mismatch of material properties Inappropriate use of materials Lack of attention to detail
Spray coolant
Irreversible structural damage to dentine occurs at temp over 70 degrees
All cavity prep under effective spray coolant
Once damaged thermally, dentine cannot recover
-visco-elastic properties ruined for life
Pulpal protection
- Prevention of bio-film contamination
- Cleaning surface
- oil-free prophylactic paste or pumice
- prophylactic slow-speed cup (500rpm) - Disinfecting surface and adjoining teeth/ surfaces
- 2% chlorhexidine
- 2.5 mins (impregnated cotton wooil)
Remaining dentine thickness
Remaining odontoblasts were reduced
-13.6% beneath RDT of 2.5-0.5mm
-33.7% beneath RDT 0.5-0.01mm
-By 99% beneath pulp exposed cavities
Reparative dentine observed following pulp exposure and reactionary dentine was observed with mean RDT of 0.77mm (2.5-0.01mm)
Cavity RDT mediates powerful influence on underlying pulp tissue vitality
Cavity RDT has little effect on reactionary dentine secretion and inflammatory activity
Gross tissue injury explains poor pulp capping prognosis following exposure and underlies need to avoid this type of injury
Following restoration, RDT of 0.5mm or greater necessary to avoid evidence of pulp injury
Pulpal death following crown preps
Aggressive insult to tooth, dentine, and odontoblasts Thermal damage LA Dessication Bacterial contamination ~10% pulpal death
Minimum of dentine thickness recommended for pulpal protection
0.7mm
Shoulder prep of 1.2mm leaves remaining dentine width of 0.7mm only in 50% of maxillary molars
Natural course of ‘untreated’ pulpal inflammation
- Pulpitis - symptomatic or asymptomatic
- Pulp necrosis
- Root canal infection, leading to periapical inflammatory lesion (periapical peiodontitis)
Pumice with which bur
Intracoronal brush for proximal box
Cup for rest of cavity
Cavity disinfection
Avoiding infection
Effective isolation - with rubber dam
Cavity and prep disinfection with chlorhexidine (conc.not so important)
Sealing dentine with adhesive should be considered for crown preps.
Cavity disinfection - effect of chlorhexidine on dentine
Dentine contains matrix metalloproteinases (MMPs), a group of neutral zinc- and calcium-dependent enzymes that regulate physiologic and pathologic metabolism of collagen-based tissues
CHX preserves hybrid layer by preventing release of MMPs from incompletely infiltrated collagen fibrils, thus preventing that will breakdown collagen
Does not improve bond strength, but preserves its durability
Posterior tooth composite shade
Lighter cures better
Aesthetic not as important
Conservative approach
Preserves pulp, re-establish healthy longterm conditions
‘Biological’ caries excavation to remove dentine but retaining dentine, so avoiding pulpal exposure
Radical approach
Remove pulpal tissue (pulpectomy) and replace with RCT
Total and uncompromising removal of caries and if pulpal exposure occurs it is then managed biologically
Vital pulp therapy
Clinical procedures aimed at
- relieving painful symptoms of pulpitis
- preventing development of destructive course of inflammation, pulp death and subsequent infection of root canal space
The pulpal wound
Has little self-healing capacity unless properly treated, in contrast to skin and mucosal tissues
Has no epithelia with which to bridge the defect
Vital pulp treatments
Partial caries removal Indirect pulp capping Direct pulp capping Partial pulpotomy Coronal pulpotomy Pulpectomy and RCT
Indirect pulp capping
Residual caries - affected dentine retained in close proximity to pulp without a breach (exposure)
Restore permanently with:
-GIC and/ or DBAs composite resin
-GIC and amalgam alloy
Review pulp status in time by signs and symptoms, and sensibility testing
Direct pulp capping
Managing exposed surface of pulp using suitable material to try and stimulate dentine bridge formation to close over exposure so repairing the breach
Pulp capping
Place rubber dam Remove any blood clot with sharp excavator Establish haemostasis -chlorhexidine -sodium hyperchloride -saline Gently apply capping agent without firm pressure (MTA) Cover wound dressing with hard setting cement e.g. GIC Restore and seal with permanent restoration Review at 1 week to check on symptoms Review at 6 months to evaulate -symptoms -reaction to thermal stimuli -sensitive to electric pulp testing Radiographic changes -periapical -dentine 'bridge' formation
Pulpal exposure damage
Calcium hydroxide pulp capping material pushed into exposure causing major bleed
Barthel 2000 method
123 pulp cappings
Teeth checked for sensitivity, percussion and palpation
Radiographs were taken to assess periapical status
Contributing factors considered
5 and 10 years
Barthel 2000 results
At 5 years -44.5% failures -18.5% questionable -27% successful cases At 10 years -79.7% failing -7.3% questionable -13% successful cases Main factor of survival influence: placement of definitive restoration within first 2 days after pulp exposure All questionable and successful cases showed radiographic evidence of calcific reactionary dentine in pulp space when compared with adjacent teeth that had no pulp exposure
Barthel 2000 conclusions
Pulp capping of carious exposures has poor outcome
Definitive restoration (immediately) > survival
Consideration given to likely need to undertake RCT in tooth with > reactionary calcifications in pulp space
Al-Hiyasat 2006 method and results
Treatment outcomes of 193 pxs with 204 pulp exposures with direct pulp capping
Radiographic review
3 years
Success rate of pulp capping 59.3%
Mechanical exposure 92.2%
Carious exposure 33.3%
Permanent restoration 80.8%
Temporary 47.3%
Class I restoration 83.8%
Proximal multiple surface restorations 56.1% MO to 28.6% MOD
Pxs’ age, sex, tooth location and position no significant effect on outcome
Al-Hiyasat 2006 conclusions
Carious pulp caps have very low success rate, worse if temporary restoration and large cavity
- direct pulp capping recommended after mechanical exposure with immediate placement of permanent restoration
- RCT would be choice of treatment if exposure was due to caries, large cavity and not able to place permanent restoration
Effect of infected dentine
Following carious exposures outcomes (pulp likely to be compromised) are poor
Avoidance of carious pulpal exposures critical to long term outcome of tooth
Management using direct pulp capping technique associated with poor prognosis for maintaining vital pulp
Extirpation of damaged pulp and RCT would then be required
Factors of importance in successful outcome to direct pulp capping
Type of injury - caries, trauma or iatrogenic
Age of px: pulp survival after 5 years was
-70% for 50-80 year olds
-85% for 30-50 years olds
-92% for 10-30 year olds
Partial pulpotomy
Invasive surgical procedure
Involves removal of inflamed coronal portion of pulp tissue
Amputate diseased tissue with diamond bur until healthy tissue exposed and haemostasis achieved
Coronal pulpotomy
Invasive surgical procedure
Removal of all coronal pulp
Amputate diseased tissue with high speed diamond bur until healthy tissue exposed and haemostasis acheived
In mature teeth, pulpotomy often carried out as temporary measure on emergency basis until time available for pulpectomy
Effect of trauma on teeth. Survival compromised if:
- Exposure of dentine and or pulp to the mouth
- Disruption of blood supply
- Unpredictable pulp responses, precipitating unnecessary pulpectomy (of a recovering pulp)
- Obliteration of pulp space by mineralised tissue (accelerated following trauma)
Determination of successful pulp management
- Accurate diagnosis
- Careful and appropriate planning
- Effective isolation - avoid further contamination
- Appropriate operative dentistry
- Effective disinfection
- Effective restoration with quality marginal seal
- Review and reassess diagnosis and prognosis
