Pulps and Nerves Flashcards
What embryonic tissues are stimulated during Apexogenesis?
HERTWIGS ROOT SHEATH
The most important part of root development is Hertwig epithelial root sheath composed of inner and outer enamel epithelium.
(IEE and OEE)
This sheath influence the adjacent MESENCHYMAL calls to differentiate into ODONTOBLASTS.
It seems that infection and inflammation are the most important factors to stopping the proliferation activity of cells.
*For this reason in apexogenesis after decontamination of inflamed part of canal with a material such as Ca(OH)2 and bacteria-sealing, we observe continuing in root formation.
Activity of cementoblasts and other regenerative cells is influenced by growth factors such as:
- epidermal growth factor (EGF),
- transforming growth factor-β (TGF-β)
- insulin-like growth factors (IGFs)
IGFs are believed to behave as proliferative factors for PDL cells, epithelial cells of Hertwig’s root sheath, or cells of Malassez.
What is the difference between Apexogenesis and Apexification?
APEXIFICATION:
inducing a calcified BARRIER at the apex of a NONVITAL tooth with incomplete root formation.
APEXOGENESIS:
VITAL pulp therapy procedure performed to encourage physiological DEVELOPMENT and formation of the root end.
Most common effect of internal bleaching of Non-Vital teeth?
External root resorption
On average, 10% of the cases of internally bleached teeth showed external cervical resorption as a consequence. The hydrogen peroxide liberated during the internal tooth bleaching presents wide permeability in the dentine and gets out through the dentine gaps in the amelodentinal junction of all human teeth.
What is the LEAST effective pulpotomy treatment?
Calcium Hydroxide
CaOH
Solubility
In radiographic analysis, the MTA group had the highest success and the CaOH group had the lowest success rate.
MTA and CH stimulate dentin bridge formation probably because of their biocompatibility and alkalinity. However, the most important distinctive feature of MTA is its good sealing ability, and it shows no signs of solubility.
The solubility of CH may cause bacterial microleakage from the furcation or coronal restoration
What is Vitapex?
Vitapex® is a premixed calcium hydroxide paste containing iodoform used as a temporary or permanent root canal filling material after pulpectomy.
CaOH
- Excellent antibacterial and bacteriostatic properties
- Promotes apexification and apexogenesis
What are the indications for NON-vital pulp therapy? (Pulpectomy) on a Primary Tooth
Nonvital pulp treatment for primary teeth diagnosed with irreversible pulpitis or necrotic pulp.
Irreversible pulpitis (e.g., excessive hemorrhage that is not controlled with a damp cotton pellet applied for several minutes) or pulp necrosis (e.g., suppuration, purulence).
The roots should exhibit minimal or NO resorption.
Percussion Sensitivity
How does CaOH promote Tertiary Dentin?
Low grade irritation
What is a radiographic sign of a successful pulpectomy?
Bone fills and returns within 6 months.
Radiolucencies begin to resolve in 6 weeks
What pulp treatment material promotes regeneration?
MTA
What is the range of treatments to a pulp exposure SECONDARY to TRAUMA in terms of size?
Size of Pulp Exposure
- <1mm: Direct Pulp Cap (MTA, CaOH)
- 1-4: Cvek pulpotomy, (if clean and adequate stopping of hemmorage)
- 4+: Pulpotomy
What does Sodium Hypochlorite do?
NaOCL
NaOCL
Disinfects and Sterilizes
Most common side effect of Ferric Sulphate?
Internal Resorption
What is the FIRST reaction of the pulp to dental caries?
⬇️
- DECREASE ⬇️ Dentin permeability by production of Sclerotic Dentin.
SCLEROSIS of Dentin
- ⬆️ Increase the deposition of mineral crystals in intratubular Dentin
- Which narrows the Dentin Tubules
- Which decreases Dentin Permiability
What is the relationship between gutta percha and latex allergy?
Chemically, gutta-percha is a polyterpene, a polymer of isoprene, or polyisoprene.
The cis structure of polyisoprene is the common latex elastomer.
Gutta percha could trigger an allergic reaction, also, in patients with latex sensitivity. Since gutta percha is the only widely acceptable material*, special care should be taken to avoid its extrusion into the periapical tissues to prevent any possible allergic reactions.
What is the compressive strength of MTA?
Comparable to?
The compressive strength of set MTA is about 70 MPa, which equals IRM and super EBA, but is less than that of amalgam
The initial compressive strength following 24 hours is 40 MPa, which increases to 67.3 MPa after 21 days.
If an Alveolar fracture occurs Apically to a roof apex, would you expect pulp vitality?
Yes
What kind of cells are used for apexification?
Mesenchymal stem cell said
It appears that dental stem cells have the potential for continued cell division and regeneration to replace dental tissues lost through trauma or disease.
What causes sclerotic dentin?
What its appearance?
What happens histologically
Dentinal sclerosis/transparent dentin-sclerosis of primary dentin is REGRESSIVE alteration in tooth characterized by CALCIFICATION of dentinal tubules.
“Glassy Appearance”
Peritubular Dentin decreases in circumference
Odontoblastic Process within tubule may or may not get occluded
It can occur as a result of injury to dentin by CARIES or ABRASION, or as part of the normal AGING process.
What is the mechanism of action of Ferric Sulfate?
🔴🚢
Coagulation and Occluding vessels 🚢
Hemostatic agent
it seems that agglutination of blood proteins occurs due to the reaction of blood with ferric and sulfate ions in acidic pH. 🔴
What is the radiopaque component of MTA?
📻⚪️
Bismuth Oxide
📻⚪️
Bismuth oxide in contact with sodium hypochlorite exhibited a CHANGE in COLOR from light yellow to dark brown
What are the two type of fibers that innervate the pulp?
Two types of sensory fibers are present in the pulp:
- A fibers - Myelinated
The A fibres predominantly innervate the dentin and are subgrouped according to their diameter and conduction velocities
More Sensitive to Stimulation
Mediate acute, sharp pain and are excited by hydromechanical events in dentinal tubules such as drilling or air-drying.
- C fibers - Unmyelinated
The C fibres innervate the body of the pulp.
Mediate a dull, burning, and poorly located pain, and are activated only by stimuli reaching the pulp proper
Once activated, the pain initiated by C fibres can radiate throughout the face and jaws. C fibre pain is associated with tissue injury and is modulated by inflammatory mediators, vascular changes in blood volume and flow, and increases in pressure.
What does a Laser Doppler measure in Pulp testing?
LDF can reliably differentiate between healthy and non-vital teeth.
Extremely accurate in predicting revascularization
Monitors dynamic changes in pulpal blood FLOW in response to pressure changes and following administration of local anaesthesia.