On the 50’sDr. Michael G.Buonocore studies’, it hasbeen creating a way toget more retentiveenamel surfaces, in otherwords: enamel etchant Pic. 1acid technique http://www.urmc.rochester.edu/dentistry/about/history.cfm It provides a strong junction between resin and enamel.
Also called Orthophosphoric acid, is a flammable chemicalcompund of formula H3PO4.On its liquid form the phosphoric acid is transparent, colorless andviscous. Is obtained by treating calcium phosphate rocks withsulfuric acid, then filtering the resultant liquid to removethe calcium sulfate.
The acid is useful in the laboratory because of its resistance to oxidation, reduction and evaporation , as glue for dentures.It forms the basis of innovative procedures such as: • Resin bonded metal retainers • Porcelain laminate veneers • Holders of orthodontics (brackets) Also solves the problems arising from the resins such as filtering and marginal pigmentation . The bond strength of etched enamel : 165 kg/cm² to 227 kg/cm² , depending on the resin.
Phosphoric acid concentrationamong 30 to 37%Objective: acts as demineralizing tothe enamel creating micro pores from20 to 30 microns in depth which allowgreater adhesion of restorativematerials. ((microretentions) in green, Pic. 2 blue compositeand yellow enamel prisms. http://www.sdpt.net/OPERATORIADENTAL/grabadoaci doesmalte.htm
1. Placed on the enamel phosphoric acid concentration of 30 to 37%2. Leave for 15 to 60 sec3. Wash with water and air for 5 sec4. Pressurized air dry for 5 sec5. Placing liquid resin or adhesive based on BIS-GMA with a solvent such as triethylene glycol dimethacrylate (TEGDMA) and a solvent such as alcohol or acetone gives the liquid flow.6. Harden for either polymerization systems.
• Etch enamel and dentin in one step, the first 15 seconds on the enamel andthen about another 15 sec dentin. (No more than this time)•Wash thoroughly from 15 to 30 sec with water•Dry with cotton or special sponge (Do not use air or alcohol)•Place adhesive hydrophilic with solvent such as water, acetone or alcohol•Volatilize with air insufflations for 5 sec•Polymerize•Place the composite http://www.youtube.com/watch?v=5DnY3h9LbQw
Directions: To condition both the surfaces of the tooth enamel and the dentin prior to placing an adhesive restoration. To clean porcelain surfaces, metal or resin Para la limpieza de superficies de porcelana, metal or resin before the accession of any resin, sealant or adhesive cements. Pic. 4http://dentala2z.co.uk/Pre10019/es Presentation: 10 mL Dropper
Product Benefits:•Ideal viscosity•Application via syringe•37% phosphoric acid to give the best results in etching dentin•2% benzalkonium chloride makes an antimicrobial etching•Provides controlled depth of dental etching•Does not dry and maintains its consistency•Predictable dental etching•No fillers or additives Pic. 5 http://dentala2z.co.uk/Pre10019/es Composition: •Phosphoric Acid •Purified Water and Thickening Agent •Methylene Blue as Dye •Benzalkonium Chloride •The operating instructions are included inside the product. Pic. 6http://dentala2z.co.uk/Pre10019/es
• It is an acid that attacks and creates channels on glass or ceramics.• It is highly toxic• Create these channels in the glass-ceramic (Leucite, feldspar, lithium disilicate, no other) producing a mechanical retention similar to that makes the phosphoric on dental tissue, then add the silane which penetrates these canaliculi and which binds chemically to the glass, the resin is on the silane as part of resinous elements are used to apply ceramic restorations on dental tissue. The silane chemically bonded to the resin.
• Silanes aid the adhesion between organic and inorganic substances. As bi-functional molecules, radicals combine their silica with the silica in restorative materials, and their co-organic radicals polymerize with the organic matrix resin cements. They can also be ceramic or bondingprimers / Coupling agents. Pic. 11 http://www.dentusonline.com/productos/detalle.php?id_pro=394
• Product http://www.ar.all.biz/g60549/• Etchant Acid /Porcelain Fgm Pic. 12• Description• Fondac Porcelain is a low viscosity gel containing 10% hydrofluoric acid etching of porcelain.• Presentation:• Pack containing: • A syringe with 2.5 ml. of product.• Indications for use: It is suitable for etching dental porcelain surface with the aim of increasing their membership in restoration processes. The engraving is critical to have an optimal interaction between the resin cement and ceramic restoration, promoting retention and encouraging resistance to the restoration.
The main advantages of etchant systems are:• Demineralization and infiltration´s dentin quickly• They are not as sensitive to different moisture conditions of dentin• Hygienic application• Consistent and stable composition• Blue dye application for facilitation
The main disadvantages are:• If not handled the right time, excessive demineralization occurs• Irreversible mistake• Expensive
¨Materiales Dentales¨, Barceló Santana, Federico Humberto“Ciencia de los materiales dentales”, Philipshttp://www.dentaflux.com/acido_fosforico_37.htmlhttp://www.sdpt.net/OPERATORIADENTAL/grabadoacidoesmalte.htmhttp://es.wikipedia.org/wiki/%C3%81cido_fosf%C3%B3ricohttp://www.kerrdental.es/materialesrestauraciones/category/EtchingMaterialsAndAdhesiveshttp://www.hispadent.es/Catalogo/2_cementos.pdfhttp://dentala2z.co.uk/Pre10019/eshttp://www.monografias.com/trabajos36/adhesion-dentina/adhesion-dentina2.shtml