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20 Cards in this Set
- Front
- Back
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What are three reasons dental pulp is vulnerable to injury?
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1) large volume of tissue with small volume of blood supply
2) terminal circulation with very little collateral vessels 3) confined calcified tissue walls (aka dentin) Dental Pulp Chapter 13; Goodis, Marshall, Tay |
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Reactionary v reparative dentin
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both are tertiary dentin
reactionary is formed by pre-existing odontoblasts reparative is formed by new odontoblastoid cells b/c there is injury to primary cells. Reparative dentin is seen in pulp exposures Murray and Cox, review article |
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how is duration of pulp exposure important when it comes to pulp capping?
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Ca(OH)2 pulp capping success was reduced from 93% to 56% when extended treatment from 1 hr to 7 days. This was because of microbial contamination.
monkey studies, Bergenholtz, Cox, Fitzgerald 1982 |
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Classic study on success rate of pulp capping
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Barthel 2000
123 pulp caps done by students 37% 5 yr success 13% 10 yr success |
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How does Ca(OH)2 work as a direct pulp cap material?
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- it is antibacterial and has a high pH (12.5)
- liquefaction necrosis of superficial pulp - coagulative necrosis of adjacent pulp - minor inflammatory response leading to dentin bridge (Cox and Bergenholtz 1985) - but dentin bridges have been shown to have tunnel defects (Aeinehchii, 2002 and Nair, Pitt Ford 2008) so always use a base material (Vitrebond) |
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Can resin modified glass ionomers (Vitrebond) be used as a direct pulp cap material?
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No, studies show it does not form dentin bridge, has impaired healing, and an inflammatory pulp response
Costa, Nascimiento, 2001 |
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Can dentin adhesives be used as a direct pulp cap material?
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No, studies show lack of dentin bridge but most importantly, it showed a persistent and significant inflammatory response
Lu, Liu, Liu 2006 Pameijer and Stanley Although Cox had shown pulpal repair in monkeys, can't use in humans |
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Can MTA be used as a direct pulp cap material?
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Yes, it has some great properties. Low solubility, high pH, antibacterial, stimulates dentin bridge
Aeinehchi 2002 - small sample size though Torabinejad Mente et al 2010 |
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How does ZOE and Ca(OH)2 affect pain/sensitivity when acting like a base for a direct pulp cap?
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Trowbridge, 1982
In cats, eugenol in ZOE inhibits in nerve activity by increasing K+ permeability and decreasing Na+ influx Ca(OH)2 didn't have an effect |
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What percentage of EDTA has been shown to be best for removing smear layer but not opening up too many aperatures/removing peritubular dentin?
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Brannstrom 1980
.2% and better with a surface action solution |
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How does tooth bleaching with hydrogen peroxide work?
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H2O2 breaks down into free radicals and form oxygen and water. The oxygen oxidizes stained areas
Gokay, 2000 |
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How does hydrogen peroxide used for bleaching affect the pulp and does heat make it worse?
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In dogs, 35% hydrogen peroxide produced a severe but reversible affect on pulp and heat at 62% didn't make this worse.
Seale and McIntosh, 1981 Also, doesn't change tooth fracture strength (Araujo, 2011) |
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What is a possible mechanism why bleaching doesn't have permanent affect on pulp?
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odontoblasts producing a heat shock protein enzyme that breaksdown heme molecules. This protein is called heme oxygenase 1
Anderson, 1999 |
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Why do we use water when prepping a cavity prep?
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B/c increase trauma shown with dry cavity preparation and rehydrating does not reverse damage
Hamilton and Kramer, 1967 |
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Does air drying a cavity prep cause pulp injury?
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No, air drying for 30 sec just showed some reversible pulpal damage.
Cotton, 1967 |
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Does occlusal relief help with endodontic pain
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Creech, 1984
occlusal relief is no better than sham relief Rosenberg et al states opposite |
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How much of remaining dentin thickness needed to prevent pulp injury when making a cavity prep?
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At least 0.5 mm
Murray, Smith, Mjor 2003 |
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Pulpal necrosis rate after tooth preparation for crowns
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3-25%
need reference for this! |
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Go through the process of how caries can cause pulpal injury.
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- Irritants such as bacterial enzymes, endotoxins, antigens etc diffuse through dentinal tubules.
- There is a zone of reactivity and in this zone, dentin becomes sclerotic. This secondary dentin formation is like a scar tissue - As invasion becomes more aggressive, odontoblasts are destroyed and leave dead tracts (tubules without odontoblasts). Now the irritants can diffuse more rapidly towards the pulp. - reparative dentin is layed down close to the pulp - calciotraumatic line develops along the pulpal margin which represents a disturbance in equilibrium of odontoblasts - severe inflammatory reaction of the pulp and pulpal damage is more due to inflammatory process than bacteria itself Trowbridge, 1981 |
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Does temperature testing a tooth cause pulpal injury?
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No. Heated gutta percha and CO2 does not
(Rickoff and Trowbridge, 1988) Peters showed CO2 doesn't as well |
