title: Effect of remineralizing agents on bond strength of orthodontic brackets: an in vitro study.
abstract: BACKGROUND
  The purpose of this study is to evaluate the effect of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) and CPP-ACP with fluoride (CPP-ACP-F) on the shear bond strength (SBS) of orthodontic brackets bonded with two different adhesive systems.
  
  
  METHODS
  One hundred twenty-six human premolar teeth were selected. One hundred twenty teeth were used for SBS testing, and six teeth were used for scanning electron microscope (SEM) examination. One hundred twenty premolars were divided into mainly three groups: CPP-ACP (group A), CPP-ACP-F (group B), and control group (group C). Each group was sub-divided into two groups according to the bonding adhesive, light cure (groups A1, B1, and C1) and chemical cure (groups A2, B2, and C2). The teeth were pre-treated with the group-specified preventive agent 1 h/day for five consecutive days. Standard edgewise brackets were bonded with the respective adhesives. SBS evaluation was done with the universal testing machine. After debonding, all the teeth were scored for adhesive remaining on the buccal surface, in accordance to adhesive remnant index, under a stereomicroscope. The acid-etched enamel surfaces were observed under SEM after treatment with CPP-ACP, CPP-ACP-F, and artificial saliva.
  
  
  RESULTS
  In light-cure adhesive group, CPP-ACP-F (B1) showed superior results compared to the control group (C1), whereas the CPP-ACP group (A1) showed lower mean SBS than the control group (C1). Both these differences were not statistically significant (p > 0.05). In chemical-cure adhesive group, control group C2 showed significantly superior results (p < 0.05) compared to group A2 and group B2. The results of two-way ANOVA showed highly significant difference due to adhesive types (p < 0.01), whereas enamel pre-treatment showed non-significant difference (p > 0.01).
  
  
  CONCLUSIONS
  The SBS of the orthodontic brackets was non-significantly affected when the brackets were cured with light-cure bonding system and treated with either CPP-ACP or CPP-ACP-F, whereas with chemical-cure adhesive, decreased bond strength was seen, which was within the clinically acceptable limits.
authors.affiliation: Chalisgaon 424101, MH, India. kapil.ladhe@gmail.com.
authors.forename: Kapil A
authors.initials: KA
authors.lastname: Ladhe
authors.forename: Murlidhar R
authors.initials: MR
authors.lastname: Sastri
authors.forename: Jyoti B
authors.initials: JB
authors.lastname: Madaan
authors.forename: Ketan K
authors.initials: KK
authors.lastname: Vakil
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D001641:Bicuspid / Q000648:ultrastructure; D002327:Cariostatic Agents / Q000737:chemistry*; D002364:Caseins / Q000737:chemistry*; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D005459:Fluorides / Q000737:chemistry*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry; D055116:Self-Curing of Dental Resins; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D002327:Cariostatic Agents; D002364:Caseins; D019279:Resin Cements; D012464:Saliva, Artificial; C477790:Transbond XT; C045638:Unite dental cement; C447032:casein phosphopeptide-amorphous calcium phosphate nanocomplex; D005459:Fluorides