title: In vitro assessment of tooth color alteration by two different types of endodontic irrigants.
abstract: OBJECTIVE
  The purpose of this study was to assess in vitro the tooth color alterations associated with two commonly used endodontic irrigants, the chlorhexidine gluconate (CHX) and the sodium hypochlorite (NaOCl) up to 15 days post-treatment. Additionally, the possible influence of endodontic access preparation on tooth color was investigated.
  
  
  METHODS
  Thirty intact human anterior teeth were used. Black adhesive tape with a 4 mm diameter window was used to standardize the enamel surface intended for color analysis. After the access cavity, preparation and the initial root canal negotiation with stainless steel hand files, the root canal shaping was completed with rotary nickel-titanium files. The teeth were divided into three groups (n = 10). Conventional syringe irrigation was performed with one irrigant for each group. The enamel surfaces were colorimetrically evaluated before access cavity, after cavity preparation and at 1, 3, 7 and 15 days post-treatment. The CIE color parameters (L*, a*, b*) were recorded and averaged for each material and the corresponding color differences (ΔE) were calculated and statistically analyzed.
  
  
  RESULTS
  The most significant factor in tooth color alteration, during the endodontic treatment, was the access preparation. CHX and NaOCl caused tooth color changes comparable with the saline. CHX and NaOCl did not increase the tooth color changes relative to the values induced by the access preparation.
  
  
  CONCLUSIONS
  The two endodontic irrigants were not able to induce tooth color alteration to a greater extent than the access preparation.
  
  
  CONCLUSIONS
  Chlorhexidine and NaOCl cannot be considered as discoloring endodontic materials. The most contributing factor in tooth color alteration during endodontic treatment in the anterior teeth is access preparation.
authors.affiliation: Department of School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece, e-mail: tasoskours@gmail.com.
authors.forename: Anastasios Dimitrios
authors.initials: AD
authors.lastname: Koursoumis
authors.affiliation: Department of School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Nikolaos P
authors.initials: NP
authors.lastname: Kerezoudis
authors.affiliation: Department of School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Afrodite
authors.initials: A
authors.lastname: Kakaboura
mesh_terms: D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003116:Color; D003124:Colorimetry / Q000379:methods; D003722:Dental Alloys / Q000737:chemistry; D003743:Dental Enamel / Q000187:drug effects; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D012965:Sodium Chloride; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D013193:Stainless Steel / Q000737:chemistry; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D014070:Tooth / Q000187:drug effects*; D014075:Tooth Discoloration / Q000145:classification
chemical_list: D003722:Dental Alloys; D012388:Root Canal Irrigants; C040654:titanium nickelide; D013193:Stainless Steel; D012965:Sodium Chloride; D009532:Nickel; D014025:Titanium; D012973:Sodium Hypochlorite; C010882:chlorhexidine gluconate; D002710:Chlorhexidine