title: Effect of different concentrations of papain gel on orthodontic bracket bonding.
abstract: BACKGROUND
  The objective of this study was to verify the hypothesis that enamel deproteinization with papain gel at concentrations of 2%, 4%, 6%, 8%, and 10% increases shear bond strength as concentration increases.
  
  
  METHODS
  A total of 180 bovine mandibular permanent incisors were used, divided into six groups (n=30), and denominated as follows: group 1 is the control group (CG) in which brackets are bonded with resin-modified glass ionomer cement (RMGIC) according to the manufacturer's recommendations and groups 2, 3, 4, 5, and 6 have brackets bonded with RMGIC after enamel deproteinization with papain gel at concentrations of 2%, 4%, 6%, 8%, and 10%, respectively. After bonding, teeth were immersed in artificial saliva and kept at a temperature of 37°C for 24 h. Mechanical tests were then performed in a universal mechanical test machine EMIC DL 5000 (Sao Jose dos Pinhais, Brazil). Values obtained were submitted to analysis of variance and then to Tukey's test (p<0.05).
  
  
  RESULTS
  The results demonstrated that groups 5 and 6 showed the highest shear bond strength, differing statistically from the other groups (p<0.05). CG with no papain gel used showed the lowest value and in turn showed no differences for groups 2, 3, and 4. As regards adhesive remnant index, CG showed statistical differences from the others. Groups 2, 3, 4, 5, and 6, in which papain gel was used, presented no statistical differences among them (p>0.05).
  
  
  CONCLUSIONS
  It was concluded that enamel deproteinization with 8% and 10% papain gel increases shear bond strength of orthodontic brackets bonded with RMGIC.
authors: Department of Orthodontics, Southwest Bahia State University UESB, Av, Otavio Santos, 305 sala 705 Centro Odontomédico Dr, Altamirando da Costa Lima, Vitória da Conquista, Bahia, Brazil. matheuspithon@gmail.com.
authors: Matheus M
authors: MM
authors: Pithon
authors: Caio S
authors: CS
authors: Ferraz
authors: Gabriel D Couto
authors: GD
authors: Oliveira
authors: Adrielle M
authors: AM
authors: Dos Santos
mesh_terms: D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003743:Dental Enamel / Q000187:drug effects* / Q000648:ultrastructure; D003746:Dental Enamel Proteins / Q000187:drug effects; D003799:Dental Stress Analysis / Q000295:instrumentation; D004305:Dose-Response Relationship, Drug; D005899:Glass Ionomer Cements / Q000737:chemistry; D055115:Light-Curing of Dental Adhesives / Q000379:methods; D008422:Materials Testing; D016910:Orthodontic Brackets; D010206:Papain / Q000008:administration & dosage / Q000494:pharmacology*; D059748:Proteolysis; D019279:Resin Cements / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors
chemical_list: D003746:Dental Enamel Proteins; D005899:Glass Ionomer Cements; D019279:Resin Cements; D012464:Saliva, Artificial; D010206:Papain