Complex direct restorations Flashcards
complex posterior direct restorations
used to replace any missing structure of teeth that have fractured, have extensive caries or have existing restorative material
usually replace on or more missing cusps
incidence of tooth fracture
molars are frequently presented fractures than premolars
buccal cusp of maxillary molars
lingual cusp of mandibular molars
most fractured teeth had been restored on three or more surfaces
Treatment plan options
Indirect restoration - onlay/crown - teeth with crowns are less likely to recieve extensive treatment (over a 10 yr period) than are teeth with large amalgam restorations - treatment of choice
DIrect restoration - complex direc restoration - less expensive, transitional restoration
Indications for Complex direct restorations
definitive final restorations - patient financial concerns
transitional restorations - pending final treatment plan, questionable pulpal or periodontal prognosis, management of caries
Indications for complex amalgam restorations
molars
lack of cervical enamel
high caries risk/poor oral hygiene
financial concerns
no esthetic requirements
no amalgam phobia
patient requires a short appointment
reduction of weakened cusps
fracture strength increases when cusps are covered (removed or reduced)
Rules for Cusp removal
if unsupported tooth structure OR caries extension from primary groove to cusp tip (up the cusp incline) is:
1/2 the distance: NO removal is indicated
1/2 to 2/3 the distance: consider cusp removal
over 2/3 the distance: remove the cusp
Cusp Reduction
Remember amalgam needs 2.0 mm for sufficient bulk - for resistance to fracture
reduce cusps to give enough space - 2.0 mm
pulp protection
direct pulp cap - small exposure, previously asymptomatic
indirect pulp cap - less than .5 mm remaining dentin thickness
thermal protection - mostly under amalgam restorations
goal of pulp capping procedures
maintain a healthy pulp
stimulate dentin bridge formation
conditions necessary for a successful pulp cap
pulp is vital
asymptomatic pre operatively
small exposure
isolated - not contaminated with saliva
no excessive hemorrhage
the restoration is well
materials for pulp protection
MTA
calcium hydroxide
calcium silicate
glass ionomer
MTA
mineratl trioxide aggregate - same compounds as Portland cement (calcium oxide, aluminum oxide, silicone dioxide)
“bioactive” and “dentinogenic” - used in direct pulp capping procedures
advantage: reparative dentinogenesis was observed earlier than with calcium hydroxide
cover with GI or RMGI
expensive
calcium hydroxide
gold standard - direct and indirect pulp capping
placed on the exposure or pink dentin
placed only on axial or pulpal floor
soluble - must not extend to margins, wash out of material will result in open margins
low compressive strength - should be covered with GI or RMGI
calcium silicate
tricalcium silicate in a hydrophyllic monomer
stimulates hydroxy apatite and secondary dentin bridge formation
direct and indirect pulp cap
light cured
increments of no more than 1.0mm
liner not required over Theracal