pins are insert into - after etch enamel and bond it with 5th generation the strength

pins are insert into:

• - enamel
• - dentin
• - DEJ
• - all

* after etch enamel and bond it with 5th generation the strength of?:

• - 5-10Mp
• - 25Mp
• - 30Mp
• - 100Mp

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Acid etching of tooth enamel and dentin adhesion:

The objective of acid etching is to provide a porous surface, since demineralization forms micropores 20 to 30 microns deep (microretentions) in green, in composite resin blue and in yellow enamel prisms.
Observe the engraving pattern in a photomicrograph performed with the scanning electron microscope (MEB), in enamel by 40% orthophosphoric acid

Acid Engraving Technique:

• Wash and clean with a small brush at low speed and pumice paste and water; You can also use baking soda for paste prophylaxis or apply it with the air system for prophylaxis. Many authors often use a microarenador with particles of aluminum oxide for the removal of the enamel surface layer.
• You can make a bevel on the enamel to improve retention, increasing the engraved surface (Black Class III, IV and V)
• Protect other teeth that are not going to be etched with strips of acetate, metal or a gingival barrier. In case of accidental etching topicar with acidified fluorphosphate once the restoration is finished, for remineralization.
• 30-37% phosphoric acid. It is recommended to use acid gel for better engraving control
• Place acid only on the bevel.
• Engraving time 15 to 20sec.
• Engraved tooth color: loses brightness. Typical chalk look.
• When the typical clinical engraving pattern is not observed after 20 seconds of engraving, you should prolong the engraving for another 30 seconds. In storms the structure is not very defined. In adults, in the cervical third there is an aprismatic layer with no defined structure, so the time should be increased to 60 seconds.
• Wash with water and air for 5 sec. (acid aspiration with high volume evacuation system and spray)
• Dry with pressurized air for 5 sec., Perpendicular to the enamel, protecting the dentin to prevent drying
• The recorded surface must be kept clean and dry until the bonding agent is used. Contact with blood or saliva prevents the adhesive from forming extensions in the enamel. If there is contamination with blood and / or saliva, you should repeat the enamel etching. To avoid contamination, perform the respective absolute insulation with rubber dam.
• In case of etching the enamel and dentin with orthophosphoric acid (total etching technique) you must take into account that the dentine is recorded in just 15 seconds (Removal of the dentinal mud) and the drying must be such that the dentine must have Some moisture, so 5 seconds of drying with pressurized air is more than enough.

Total etching (enamel and dentin) with orthophosphoric acid should only be used with the first adhesives (Engraving acid applied and washed to remove dentin mud; initiator and adhesive applied separately) and second generation (Engraving acid applied and washed to remove dentin mud ; initiator and adhesive applied in a single solution).

Adhesion to dentin:

Acid dentin cannot be etched because it has a large percentage of organic tissue, so macroretensions must be made; Micro-sanding in cervical and undercuts will only achieve retention of the material, but not a marginal seal or an interaction between the material and the tooth.
Specific or chemical adhesion must be performed between the dentin resin interface.

Disadvantages for dentin adhesion:

- Being composed of collagen and hydroxyapatite.
- Tubular in nature, which produces a variable area and a constant fluid fluid.
- Presence of dentinal mud by carving the cavity

Solution to develop a dentin adhesion:

Develop a liquid with double reaction molecules:

that reacts with calcium and dentine collagen. In theory, the adhesive must be hydrophilic. Dentin binding is performed microscopically with the collagen and with the dentinal tubule.

- Smear Layer:

It is the mud or dentin mud. In electron microscopy, the adhesion of this mud to dentin has been determined. The smear layer has two layers; the surface layer that is thin and is removed with pressurized water. And the deep layer that makes contact with the dentin and is well attached to the dentin.

All adhesives act on the deep layer of dentinal mud. The layer can be totally or partially removed, preserved and modified or restructured and integrated.

It is more convenient to classify adhesives in generations. The adhesive creates a chemical bond between calcium and resin. The fluid resin polymerizes and forms the tags or interdigitations of retention, mechanical physical lock, is a bonding resin that gets into the dentinal tubules.

Active ingredients of the first: they condition the dentin to receive the adhesive. They must have one or more of these components: TEG-DMA, HEMA, 4 META-MMA-TBB, PENTA.

The dentin hybridization layer is insoluble, so it would not allow the passage of fluoride ions. The adhesive should not be absolutely hard, as it would fracture; It must have some elasticity, which allows it to compensate for the contraction of the composite by hardening and prevent the composite from coming off. (Lower post-operative sensitivity and decreased marginal filtration) The adhesives can be multi component, bi component or mono component.