It is an innovative, modern achievement of dentistry, which allows aesthetic results, generally, that previously could not be achieved. FIG.3 www.google.com
Restorations with important achievements: Aesthetic Biological Functional Being able to adhere does not only resin, but also structures ceramics to dental tissue.
Induction of oral fluid and bacteria in microscopic fissures that exist between the surface of the prepared tooth and the restorative material
In amalgam: produces no continuity between the two structures, but over time the interface is sealed, since it produces corrosion products that seal. In ionomer: fluoride is released which prevents recurrent caries. In resins: the direct filling are inert, do not produce marginal seal, therefore we must seek other methods of achieving marginal seal.
Some may be polymerized onlywith the components includedin its composition:There are auto polymerizing,self-curing, or chemicalactivation. FIG.5 www.google.com
Others need a lightgenerating device to becured: they are thephotopolymerizable, lightphotocurable or activation(with light). FIG. 4 Self-etching adhesive system photocurable of a single component for the dentin and the enamel which releases fluoride. www.google.com
FIRST HYDROPHOBICSECOND MIXEDTHIRD HYDROPHILICFOURT HYBRID LAYERFIFTH SINGLE COMPONENTSSIXTH ETCHINGSEVENTH ALL IN ONE
FIRST: Before 1980. Without conditioning on dentin. It had very low adhesion values in dentin: 2-7 MP, the enamel MP 24-27. SECOND: 3 times greater adhesion to dentin and enamel 30-50%. THIRD: They generate bond strength similar to that between enamel and resin. It was only trying to produce a chemical bond, subsequently obtained a micro mechanical junction, by forming an interdiffusion layer which leads to high levels of adhesion.
FOURTH: Adhesion greater than 20 MP FIFTH: Based on hybridization dentin layer. Easier use than previous. Resistance similar to those of the fourth generation. SIXTH: It begins to use primers etching and mixtures of adhesives with primers and phosphoric acid is removed except for the sound enamel. SEVENTH: Among the improvements we can mention the self-etching adhesives and those which do not require mixing.
MECHANICAL OR PHYSICAL Exclusively for one mechanical locking. It is based on morphological features of the parts (Grasp) and may be at levels: Macromechanic: undermined Micromechanic: differs from the previous one in the size of the parts.
Forces are generated between both parts. They are interactions at atomic level or molecular, based on primary joints (chemicals: ionic, covalent, metal) and secondary (hydrogen bridges and oscillating dipoles). The ideal is for primary joints to be produced.
Low service tension Low Viscosity Dimensional Stability Adequate Mechanical Properties: to resist forces of mastication Hydro resistance Biological Compatibility
High surface energy to attract the liquid so that it can be drained. In order for that, it is necessary for it to be clean with a smooth surface (favors the chemical union but not the mechanical). This is, the surface must be wettable by the adhesive. FIG.4 www.google.com
NAME COMMERCIAL SOLVENT CURING TIME HOMETETRIC N IVOCLAR ETHANOL 10 SEC.BOND VIVADENTPRIME & DENTSPLY ACETONE 10 SEC.BOND NTONE COAT COLTENE WATER 30 SEC.BOND SLTE-ECONOM IVOCLAR ETHANOL 20 SEC.BOND VIVADENTADPER 3M ETHANOL 10 SEC.SINGLEBOND 2
Retain most of the tooth structure Achieve a lasting and optimal retention Prevent microleakage
Photopolymerizable (marginal percolation) Auto curing Dual, Auto or phtocuring
ADVANTAGES DISADVANTAGESIncrease tooth retention and effort There is a greater chance of dentin overmineralizeHigher marginal adaptation Need of long clinical timeLower percentage of secondary Possibility of contaminating dentaldecay structureDecrease in sensitivity Major risk of over drying the dental tissue or chance of moisture in the substrate adherent