dental materials


What type of bonding agent is more important to dentin than enamel, contains hydrophilic groups to penetrate wet etched dentin, and mechanically bonds to dentin?


primer


What type of bond is a chemical bond, contains a hydrophobic group that chemically bonds to the composite resin, and bonds mechanically to metals/porcelains?


resin adhesive


phosphoric acid etching of both enamel and dentin with a separate step that includes rinsing off the acid and lightly drying the tooth


total-etch or universal etch


layer formed be collagen fibrils, and ty dentin bonding resin, the etched dentin surface is called what


hybrid layer


The bond that links dentin with the restorative material is accomplished through what layer?


hybrid layer


Many of the current all-etch bonding agents are desingated as universal bonding agents, what does this mean?


they are suitable for bonding on all enamel, dentin, and restorative surfaces


What type of bonding system has one and two bonding systems that have been developed that incorporate acidic groups in the boning agent that will etch enamel and dentin and allow penetration of the resin without the need for rinsing and drying?


self-etching bonding agents


What are 2 drawbacks of self-etching primers?


they do not adequately etch uncut enamelcan't be used in direct bonding to unprepared enamel such as sealants or veneers


type of cure in which a chemical reaction occurs when two resins, a base and with chemical activators and a catalyst are mixed together


self-cure


cure that uses a light in the blue wave range to activate a chemical that sets off the polymerization reaction or curing process


light-cure


cure that uses a combination of self and light-cure ingredients, these resins can be activated by light or can cure chemically without application of curing light


dual-cure


What type of bond is a resin to resin (composite)


chemical


What type of bond is resin to metal or porcelain?


mechanical


is a dentinal or enamel bond stronger?


enamel


How long must you re etch an enamel bond if it becomes contaminated?


15 seconds


The following things make up what layer? tooth debris, plaque, bacteria, pellicle, saliva, blood


smear layer


In the all etch technique, should you etch dentin or enamel first?


enamel for 10then dentin for 10


What happens if you etch dentin for longer than 20 seconds?


decreases bond strengthcauses post treatment hypersensitivity


Why is it important to keep the dentin moist after rinsing the etch for 10 seconds to remove excess water?


it keeps the collagen fibers fluffed


What causes the following to happen? occlude dentinal tubules, block penetration by dentin bonding resins, dentin/resin interface fracture


collagen fibers have collapsed


_________ dissolved in resin allow resin penetration (moist dentin) and collagen fibrils into the dentinal tubules


solvents


leakage of fluids and bacteria between tooth and restoration


microleakage


What are 4 causes of microleakage?


contamination (blood, saliva, smear layers, oil)shrinkage unbonded restorationscoefficient of thermal expansion


What are three of the results of microleakage?


recurrent decaystainingpost operative sensitivity from percolation


Pain of hypersensitivity common with bonded restorations is felt through what?


odontoblasts in pulp at dentinal junction


how far do odontoblasts extend in the dentinal tubule?


1/3 of the way in


dentinal tubule contains a column of pulpal fluid and the dentinal fluid will move with pressure changes, what is this called?


hydrodynamic theory of tooth sensitivity


pressure receptors in the odontoblast only illicit what type of response?


pain


What is the primary reason for hypersensitivity?


unsealed dentinal tubules


what are three contributing factors to dentinal hypersensitivity?


over dryingover etchedcomposit is cured in too large of increments, causin contraction stress on tooth