title: Influence of atmospheric pressure plasma treatment on mechanical proprieties of enamel and sealant bond strength.
abstract: OBJECTIVE
  To define the effect of APP treatments on the mechanical properties of enamel and on its ability to promote sealant bonding to unetched enamel.
  
  
  METHODS
  Human molar teeth were sectioned exposing flat enamel regions at the buccal and lingual surfaces. The specimens were divided into two substrate groups (etched and unetched) and distributed over three surface treatments (i) 5 slm Argon APP treatment, NaOH surface treatment, and (iii) compressed air application (control). The Enamel surfaces were characterized by SEM, IFM, and Goniometer instruments. For the mechanical tests nanoindentation and microshear bond strength were employed. Initial data evaluation comprised normality verification (SPS S software) and variance checking and the appropriated statistical analysis model employed. For all statistical inferences, significance was set at 0.05.
  
  
  RESULTS
  SE was significantly higher for the etched and unetched group treated with Plasma relative to the NaOH and control groups. Nanoindentation testing determined that Rank hardness was significantly higher in the control and Plasma group relative to NaOH for the etched group. Rank Elastic Modulus was significantly higher on Control groups relative to NaOH and Plasma groups for the etched substrate. No difference was detected between treatments for the unetched group. For the µSBS test, we observed that APP treatment on etched and unetched enamel increased bonds significantly (p < 0.001).
  
  
  CONCLUSIONS
  This study demonstrated that APP increased SE, surface wettability and bond strength between enamel and sealants potentially serving as a substitute for conventional acid etching procedures or as an adjuvant for self-etch sealants.
authors.affiliation: Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, New York.
authors.forename: Hellen S
authors.initials: HS
authors.lastname: Teixeira
authors.affiliation: Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, New York.
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Coelho
authors.affiliation: Department of Basic Science and Craniofacial Biology, New York University College of Dentistry, New York, New York.
authors.forename: Simone
authors.initials: S
authors.lastname: Duarte
authors.affiliation: Department of Epidemiology and Health Promotion, New York University College of Dentistry, New York, New York.
authors.forename: Malvin N
authors.initials: MN
authors.lastname: Janal
authors.affiliation: Department of Prosthodontics, Federal University of Minas Gerais, Belo Horizonte School of dentistry, Belo Horizonte, MG, Brazil.
authors.forename: Nelson
authors.initials: N
authors.lastname: Silva
authors.affiliation: Department of Biomaterials, Biomimetic & Biophotonics King's College London Dental Institute, London, UK.
authors.forename: Van P
authors.initials: VP
authors.lastname: Thompson
mesh_terms: D003743:Dental Enamel; D005260:Female; D006801:Humans; D008297:Male; D008963:Molar; D010895:Pit and Fissure Sealants / Q000737:chemistry*; D058626:Plasma Gases
chemical_list: D010895:Pit and Fissure Sealants; D058626:Plasma Gases
keywords: atmospheric pressure plasma; bonding; enamel; pit and fissures; sealants