title: Effect of bromelain and papain gel on enamel deproteinisation before orthodontic bracket bonding.
abstract: OBJECTIVE
  To test the hypothesis that enamel surface deproteinisation with different concentrations of bromelain in association with 10% papain increases the shear bond strength (SBS) of brackets bonded with orthodontic composite and resin modified glass ionomer cement (RMGIC).
  
  
  METHODS
  Orthodontic brackets were attached according to the following protocols to 195 bovine incisors, which were acquired and divided into 13 groups: 1) Transbond XT (TXT) according to the manufacturer's recommendations; 2) Deproteinisation with 3% bromelain (BD) plus 10% papain and TXT; 3) 6% BD plus 10% Papain and TXT; 4) RMGIC, without enamel deproteinisation and without acid etching; 5) RMGIC, with 3% BD plus 10% papain and without acid etching; 6) RMGIC, with 6% BD plus 10% papain and without acid etching; 7) attachment using RMGIC following etching with polyacrylic acid; 8) 3% BD plus 10% papain, attachment using RMGIC and etching with polyacrylic acid; 9) 6% BD plus 10% papain, and attachment using RMGIC following etching with polyacrylic acid; 10) etching with 37% phosphoric acid and attachment using RMGIC; 11) 3% BD plus 10% papain, etching with 37% phosphoric acid and attachment using RMGIC; 12) 6% BD plus 10% papain, etching with 37% phosphoric acid and attachment using RMGIC; 13) deproteinisation with 2.5% sodium hypochlorite (NaOCl), etching with polyacrylic acid and RMGIC. After bonding, the brackets were removed by a universal mechanical testing machine, which recorded shear bond strength at failure. The material remaining on the tooth was assessed using the adhesive remnant index (ARI).
  
  
  RESULTS
  Deproteinisation with 3% and 6% bromelain gel plus papain significantly increased the shear bond strength (p < 0.05), when acid etching was performed with phosphoric acid, followed by primer application and attachment using Transbond XT (Group 3) and when attached with RMGIC without etching. Deproteinisation with 6% bromelain gel plus papain significantly increased (p < 0.05) the ARI score only when attachment was performed using RMGIC, without etching (Group 6).
  
  
  CONCLUSIONS
  Deproteinisation with bromelain associated with papain in a gel increased the shear bond strength and is recommended before orthodontic bracket attachment.
authors.forename: Matheus Melo
authors.initials: MM
authors.lastname: Pithon
authors.forename: Matheus Souza
authors.initials: MS
authors.lastname: Campos
authors.forename: Raildo da Silva
authors.initials: Rda S
authors.lastname: Coqueiro
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000180:Acrylic Resins / Q000737:chemistry; D000818:Animals; D001963:Bromelains / Q000494:pharmacology*; D002417:Cattle; D001840:Dental Bonding / Q000379:methods*; D003743:Dental Enamel / Q000187:drug effects*; D003746:Dental Enamel Proteins / Q000187:drug effects*; D003799:Dental Stress Analysis / Q000295:instrumentation; D005782:Gels; D005899:Glass Ionomer Cements / Q000737:chemistry; D008422:Materials Testing; D016910:Orthodontic Brackets; D010206:Papain / Q000494:pharmacology*; D010756:Phosphoric Acids / Q000737:chemistry; D059748:Proteolysis; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D003746:Dental Enamel Proteins; D005782:Gels; D005899:Glass Ionomer Cements; C516145:Multicure cement; D010756:Phosphoric Acids; D019279:Resin Cements; C477790:Transbond XT; C006903:carbopol 940; D001963:Bromelains; D012973:Sodium Hypochlorite; C030242:phosphoric acid; D010206:Papain