title: Microleakage of Glass Ionomer-based Provisional Cement in CAD/CAM-Fabricated Interim Crowns: An in vitro Study.
abstract: OBJECTIVE
  The aim of this study was to compare in vitro the marginal microleakage of glass ionomer-based provisional cement with resin-based provisional cement and zinc oxide non-eugenol (ZONE) provisional cement in computer-aided design and computer-aided manufacturing (CAD/CAM)-fabricated interim restorations.
  
  
  METHODS
  Fifteen intact human premolars were prepared in a standardized manner for complete coverage of crown restorations. Interim crowns for the prepared teeth were then fabricated using CAD/CAM, and the specimens were randomized into three groups of provisional cementing agents (n = 5 each): Glass ionomer-based provisional cement (GC Fuji TEMP LT™), bisphenol-A-glycidyldimethacrylate (Bis-GMA)/ triethylene glycol dimethacrylate (TEGDMA) resin-based cement (UltraTemp® REZ), and ZONE cement (TempBond NE). After 24 hours of storage in distilled water at 37°C, the specimens were thermocycled and then stored again for 24 hours in distilled water at room temperature. Next, the specimens were placed in freshly prepared 2% aqueous methylene blue dye for 24 hours and then embedded in autopolymerizing acrylic resin blocks and sectioned in buccolingual and mesiodistal directions to assess dye penetration using a stereomicroscope. The results were statistically analyzed using a nonparametric Kruskal-Wallis test. Dunn's post hoc test with a Bonferroni correction test was used to compute multiple pairwise comparisons that identified differences among groups; the level of significance was set at p < 0.05.
  
  
  RESULTS
  All groups exhibited marginal microleakage; the Bis-GMA/TEGDMA resin-based provisional cement demonstrated the lowest microleakage scores, which were statistically different from those of the glass ionomer-based provisional cement and the ZONE cement.
  
  
  CONCLUSIONS
  The provisional cementing agents exhibited different sealing abilities. The Bis-GMA/TEGDMA resin-based provisional cement exhibited the most effective favorable sealing properties against dye penetration compared with the glass ionomer-based provisional cement and conventional ZONE cement.
  
  
  CONCLUSIONS
  Newly introduced glass ionomer-based provisional cement proved to be inferior to resin-based provisional cement as far as marginal microleakage is concerned.
authors: Department of Prosthodontics, College of Dentistry, Qassim University, Al-Mulaydah, Qassim, Kingdom of Saudi Arabia, e-mail: dr.rafat.farah@qudent.org; ri.farah@qu.edu.sa.
authors: Ra'fat I
authors: RI
authors: Farah
authors: Department of Prosthodontics, College of Dentistry, Qassim University, Al-Mulaydah, Qassim, Kingdom of Saudi Arabia.
authors: Naji
authors: N
authors: Al-Harethi
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate; D017076:Computer-Aided Design; D003442:Crowns; D003763:Dental Leakage; D005899:Glass Ionomer Cements; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids
chemical_list: D005899:Glass Ionomer Cements; D011109:Polymethacrylic Acids; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate
keywords: Dye penetration; Interim restorations; Marginal microleakage Provisional cements.