title: In vitro evaluation of topical fluoride pH and their effect on surface hardness of composite resin-based restorative materials.
abstract: OBJECTIVE
  The aim of the study was to correlate the pH and fluoride ion uptake with surface hardness of composite resin based restorative materials after topical fluoride application.
  
  
  METHODS
  Forty disks of each of test materials Composite (Filtek Z350XT, 3M ESPE, St Paul, MN, USA), Resin modified glass ionomer (Vitremer) and Compomer (Dyract AP) were made and ten disks of each material were placed in different test solutions - 1.23% APF gel, Sodium fluoride mouth rinse, 0.9% neutral fluoride and distilled water (Control group). After 36 hours of immersion, specimens were subjected to microhardness testing machine for evaluation of surface hardness.
  
  
  RESULTS
  The greater hardness deterioration for all materials resulted with 1.23% APF gel when compared to the control group. Composite (Filtek Z350XT, 3M ESPE, St Paul, MN, USA) showed 17.13 VHN (control group 59.11 VHN). Vitremer showed 9.71 VHN (control group 37.71 VHN). Compomer showed 19.22 VHN (control group 36.78 VHN).
  
  
  CONCLUSIONS
  1.23% ApF gel significantly decreased hardness of composite, Vitremer and Compomer. Hardness deterioration associated with sodium fluoride mouth rinse and 0.9% neutral fluoride was less compared to 1.23% ApF gel.
authors.affiliation: Associate Professor, Department of Restorative Dentistry, College of Dentistry Taibah University, Near Hizam Street Al-Madinah Al-Munawwarah, Saudi Arabia.
authors.forename: Abdul
authors.initials: A
authors.lastname: Mujeeb
authors.affiliation: Assistant Professor, Department of Oromaxillofacial Surgery, College of Dentistry, Taibah University, Near Hizam Street Al-Madinah Al-Munawwarah, Saudi Arabia.
authors.forename: Samir
authors.initials: S
authors.lastname: Mansuri
authors.affiliation: Assistant Professor, Department of Restorative Dentistry, College of Dentistry Taibah University, Medina, Saudi Arabia.
authors.forename: Seema Abid
authors.initials: SA
authors.lastname: Hussain
authors.affiliation: Specialist, Department of Orthodonticsa, Asir Specialist Center, Abha Ksa.
authors.forename: Kausar
authors.initials: K
authors.lastname: Ramaswamy
mesh_terms: D000149:Acidulated Phosphate Fluoride / Q000737:chemistry; D002327:Cariostatic Agents / Q000737:chemistry*; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D005459:Fluorides / Q000737:chemistry; D005460:Fluorides, Topical / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry; D006244:Hardness; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007101:Immersion; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D002327:Cariostatic Agents; D020770:Compomers; D003188:Composite Resins; D003764:Dental Materials; C088486:Dyract; D005460:Fluorides, Topical; D005899:Glass Ionomer Cements; D019279:Resin Cements; C084550:Vitremer; C533204:filtek Z350; D014867:Water; D000149:Acidulated Phosphate Fluoride; D012969:Sodium Fluoride; D005459:Fluorides