title: Evaluating the Effect of CPP-ACP as a Final Irrigant in Improving the Micro-Hardness of Erosive Root Dentin and its Influence on the Bond Strength of Self Etch Resin Sealer - An In-vitro Study.
abstract: BACKGROUND
  Smear layer removal from the root canal wall involves the use of 17% EDTA and 5.25% sodium hypochlorite, which thereby improves the adhesion of obturating materials to root dentin. But these chemical irrigants have shown to decrease micro hardness, increase roughness, cause erosion and reduce the root dentin fracture toughness. To combat these adverse effects, studies can be focussed on the remineralisation of the erosive root dentin and this novel idea has been utilized in the present study.
  
  
  OBJECTIVE
  To evaluate the micro hardness of erosive root dentin when Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) was used as a final irrigant and its influence on resin sealer bonding tested by push-out bond strength method.
  
  
  METHODS
  Sixty extracted maxillary incisors were divided into three groups based on the final irrigation protocol. Group 1-normal saline, Group 2-17% EDTA (Ethylene Diamine Tetraacetic Acid) + 5.25% NaOCl (Sodium Hypochlorite), Group 3 - 17% EDTA + 5.25% NaOCl + CPP-ACP; each group was divided into two subgroups. Half the specimens of each group were evaluated for Vicker's micro hardness test after the treatment. In continuation with the above methodology the remaining specimens were tested for push-out bond strength after obturation of the specimens with self etch adhesive resin sealer and conventional 6% gutta percha cones.
  
  
  RESULTS
  Micro hardness was statistically analysed using Kruskal Wallis test and push-out bond strength was evaluated using Mann Whitney test and paired t-test. CPP-ACP treated group showed increased micro hardness (p<0.05). There was no statistically significant difference between the push-out bond strength values between group EDTA + NaOCl group and EDTA + NaOCl + CPP-ACP group.
  
  
  CONCLUSIONS
  Within the limitations of this study it can be concluded that, CPP-ACP improved the micro hardness of erosive root dentin and is not affecting its bond strength. Therefore, CPP-ACP may be used before bonding procedures for promoting remineralization of root dentin.
authors.affiliation: Assistant Professor, Department of Conservative Dentistry and Endodontics, Drs. Sudha and Nageswara Rao Institute of Dental Sciences , Gannavaram, Andhra Pradesh, India .
authors.forename: Bhavana
authors.initials: B
authors.lastname: Gandhi
authors.affiliation: Assistant Professor, Department of Conservative Dentistry and Endodontics, Drs. Sudha and Nageswara Rao Institute of Dental Sciences , Gannavaram, Andhra Pradesh, India .
authors.forename: Swetha
authors.initials: S
authors.lastname: Bollineni
authors.affiliation: Associate Professor, Department of Conservative Dentistry and Endodontics, Drs. Sudha and Nageswara Rao Institute of Dental Sciences , Gannavaram, Andhra Pradesh, India .
authors.forename: Ravi Kumar
authors.initials: RK
authors.lastname: Janga
authors.affiliation: Professor, Department of Conservative Dentistry and Endodontics, Drs. Sudha and Nageswara Rao Institute of Dental Sciences , Gannavaram, Andhra Pradesh, India .
authors.forename: Disha
authors.initials: D
authors.lastname: Saraswati
authors.affiliation: Professor, Department of Conservative Dentistry and Endodontics, Drs. Sudha and Nageswara Rao Institute of Dental Sciences , Gannavaram, Andhra Pradesh, India .
authors.forename: Mandava Ramesh
authors.initials: MR
authors.lastname: Babu
keywords: Dentin; Ethylenediaminetetraacetic acid; Resin cement; Sodium hypochlorite