non-vital Bleaching Flashcards
need for bleaching and though process
treatment choice based on conservation of tooth structure and its effectiveness in lighting tooth discoloration
MOST CONSERVATIVE WAY
breakdown of discoloration
external
internal
- systemic factors
- local factors
external discoloration comes from
tobacco, colored plaques, food stains, drug stains
internal discoloration by systemic is usually caused by?
SYSTEMIC factors like
- porphyria
- AI
- fluorisis
- tetracycline
internal discoloration by local factors is usually caused by?
trauma
protein degradation products
pulp remnnants
agents used in RCT
metallic salts (mercury, silver, copper, iodine)
iron sulfide?
black compound that resutls from trauma and process of hemolysis
etiology of staining from trauma
trauma – RBC– hemolysis – hemoglobin – iron and hydrogen sulfite mack IRON SULFIDE (black compound)
iron sulfide from>
iron and hydrogen sulfide
when selecting a case keep in mind?
etiology
complete RTC?
intact tooth structure 9like if not enough - not doing internal bleaching – crown may be better choice)
contraindications for internal bleaching
- extensive restoration s
- crown defects (fractures, hypoplastic enamel)
- severely underminded enamel
- discoloration due to metallic salt – like amalagame or silver cone
bleaching agents used
- sodium perborate
- 3% hydrogen peroxide
- 30% hydrogen peroxide (superoxol)
- 3015% carbamide peroxide (Opalescence) – external
methods of bleaching
- thermocatalytic technique (superoxol + heat – in office)
- waling bleach with sodium perborate and water or sodium perborate and H2O2
- combination
relationship between bleaching and root resorption
Intra-coronal bleaching with H2O2 can be occassionally assoicated with EXTERNAL ROOT RESORPTION
PATHOLOGIC MECHANISM associated with intra coronal bleaching and external root resorption
cementum defects - mainly at the CEJ (cemento-enamel junction) signficantly enhances H2O2 seepage
CEJ relationships
- edge to edge
- overlap
- GAP
- why you can get seepage of the material
cementum defects occurence? IMPLICATION?
can be up to 25 % in anterior teeth – WHY NEED A BARRIER
T/F barrier thickness and its relation to the CEJ is more important than the choice of material in preventing H2O2 seepage? describe
TRUE
- IRM ZOE composite and Glass ionomer can be used as barrier
- should be places 2mm intra-coronal isolating base – at the CEJ level
concept of barrier
should block all of dentinal tubules leading from the pulp chamber which reach the tooth hsurface apical to the epithelial attachment – so that the bleaching agents stay inside the access cavity
CEJ lower where?
on facial and palatal and higher on the proximals
barrier placement
1 mm below and above CEJ so use the labial CEJ as a guide - leaves the proximal dentinal tubules unprotected – as it is higher there
so probe around tooth and measure where CEJ is then place barrier there
diagnostic step (step 1)
determine reason and chec vitality of tooth
complete the RCT and retreat if obturation is inadequate
record shade?
step 2
step 3
measurements of barrier
step 4
tooth isolation
step 5
access cavity
- if any necrotic tissue there / left - remove this
step 6 - remove?
space for barrier material
- remove GP to level of 2 mm BELOW the CEJ so space for barrier material
placement of barrier material
1mm above the CEJ uniformly
in office thermocatalytic technique usually uses?
30% hydrogen peroxide – heat it up - then cool – heat and cool repeat
walking bleach technique
one he recommends
sodium perborate with 30% – becomes a paste -
fill chamber
- seal with cavit
could do more than one application
