Enamel and dentine bonding Flashcards
Adhesive material functions
seal vulnerable pits and fissures, conserve tooth tissue and reduce microleakage
Three approaches to achieving attachment
micro-mechanical e.g., acid etch, chemical e.g., coupling agents and complex e.g., modern dentine bonding agents
Agent demonstrates wetting at?
contact angle
Low contact angle of bonding agent gives good or bad wetting
good wetting
Large contact angle of bonding agent gives good or bad wetting
bad wetting
What does acid etch do?
decalcify enamel prisms and forms micromechanical tags into which bonding resin may flow
Does acid etch increase or decrease enamel surface energy?
increase
Factors affecting acid etch?
etching time, washing and drying
Dentine problems of bonding
dentine is hydrophilic and adhesives are hydrophobic, dentine if vital, dentine covered by a smear layer
What are primers/ dentine conditioners?
Acids - open dentinal tubules and demineralise dentine surface
What do primers act as?
adhesives
Name a popular primer
HEMA
Problem with HEMA
dermatological irritant
Ideal restorative material features
viscosity, working time, setting time
What does a restorative material need to chemically withstand?
pH, temperature, solvents and corrosion
