Adhesive materials Flashcards
Define adhesion/bonding
the joining together of two objects using a glue or cement
Most dental materials that are adhesive involve what type of adhesion?
micromechanical adhesion/bonding
Def. micromechanical bonding
bonding using surface irregularities smaller than can be seen with the naked eye or felt with an explorer
2 main adv. of micromechanical bonding over macromech. bonding
- a greater # of small surface irregularities are used compared to macromech. bonding
- force is more evenly distributed on the joint w/micromech. bonding making it stronger than macromech. bonding
Give an example of how macromechanical bonding is used in dentistry
- for cementing or luting crowns and bridges to teeth with “nonadhesive” cements
Uses of adhesion/bonding in dentistry (3)
- retention of restorations
- reduction of microleakage
- and staining at the margins - reduction of recurrent caries
When are undercuts and other mechanical locks not necessary in restorative DDS?
When adhesive materials are used
Def. microleakage and state its main disadv
the seeping and leaking of fluids and bacteria between the tooth/restoration jxn or interface
- it increases the likelihood of recurrent caries
What causes post-operative sensitivity?
The movement of fluids and bacteria in and out of the interface btwn tooth structure and restoration
If the pulp is irritated by fluid mvmnt or bacterial metabolic waste (acids), pain occurs
Define/explain the phenomenon k.a “percolation”
When teeth are heated and cooled by the ingestion of hot and cold foods, expansion and contraction occur
- If the coefficient of thermal expansion for a restorative material does not match that of the tooth, they expand and contract at different rates;
- Percolation describes this repeated contraction & expansion of teeth and restorations at diff rates, resulting in fluids being sucked in and pushed out of the margins of a restoration
Recurrent caries
- decay that occurs at the margin of a restoration
