title: Comparison of the surface hardness among 3 materials used in an experimental apexification model under moist and dry environments.
abstract: BACKGROUND
  Procedures used in single-visit or multiple-visit approaches to apical barrier creation were used with an experimental apexification model to test the surface hardness of 3 materials. The purpose of this study was to examine the microhardness of the materials after setting in moist or dry conditions.
  
  
  METHODS
  A simulated open apex and periapical environment model was created using polyethylene tubes placed into a porous block filled with phosphate-buffered saline. White ProRoot Mineral Trioxide Aggregate (MTA; Dentsply Tulsa Dental, Tulsa, OK), EndoSequence Root Repair Material (ESRRM; Brasseler USA, Savannah, GA), and Biodentine (BD; Septodont, Louisville, CO) were mixed and placed into the apical 4 mm of the tubes (N = 15). The moist group had a damp cotton pellet above the test materials (mineral trioxide aggregate or ESSRM) with Fuji II LC (GC America, Alsip, IL) sealing the coronal segment. The dry group had gutta-percha placed directly against the test materials with amalgam sealing the coronal segment. After 10 days of storage in 100% humidity at 37°C, samples were sectioned, and microhardness was independently measured at 2 mm and 4 mm from the apical end. Differences were assessed using analysis of variance and a Tukey post hoc test (α = .05).
  
  
  RESULTS
  Analysis of variance analyses showed no significant effect of wet or dry conditions on resultant material hardness. A Tukey post hoc test showed that using ESRRM and BD would not result in a significant difference in hardness, but using MTA would result in statistically significant different hardness values when compared with ESRRM or BD.
  
  
  CONCLUSIONS
  Either a moist or dry environment could allow hardening of materials; thus, both methods could be acceptable for clinical treatment procedures.
authors.affiliation: Department of Endodontics, LSU Health Sciences Center, School of Dentistry, New Orleans, Louisiana.
authors.forename: Victor
authors.initials: V
authors.lastname: Caronna
authors.affiliation: Department of Endodontics, LSU Health Sciences Center, School of Dentistry, New Orleans, Louisiana.
authors.forename: Van
authors.initials: V
authors.lastname: Himel
authors.affiliation: Biostatistics Program, LSU School of Public Health, New Orleans, Louisiana.
authors.forename: Qingzhao
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Department of Biomaterials, LSU Health Sciences Center, New Orleans, Louisiana.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Zhang
authors.affiliation: Department of Endodontics, LSU Health Sciences Center, School of Dentistry, New Orleans, Louisiana. Electronic address: ksabey@lsuhsc.edu.
authors.forename: Kent
authors.initials: K
authors.lastname: Sabey
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D056624:Apexification / Q000379:methods*; D017610:Calcium Compounds / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003890:Desiccation; D004338:Drug Combinations; D005899:Glass Ionomer Cements / Q000737:chemistry; D006171:Gutta-Percha / Q000737:chemistry; D006244:Hardness; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008953:Models, Anatomic; D010087:Oxides / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D019227:Tooth Apex / Q000033:anatomy & histology
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D002130:Calcium Phosphates; D004338:Drug Combinations; C550603:EndoSequence root repair material; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D010087:Oxides; D012117:Resins, Synthetic; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; C506393:tricalcium silicate; D003723:Dental Amalgam; D006171:Gutta-Percha
keywords: Biodentine; EndoSequence Root Repair Material; immediate apexification; microhardness; white mineral trioxide aggregate