title: Microleakage of Four Dental Cements in Metal Ceramic Restorations With Open Margins.
abstract: BACKGROUND
  Fixed prosthodontics is a routine dental treatment and microleakage is a major cause of its failure.
  
  
  OBJECTIVE
  The aim of this study was to assess the marginal microleakage of four cements in metal ceramic restorations with adapted and open margins.
  
  
  METHODS
  Sixty sound human premolars were selected for this experimental study performed in Tehran, Iran and prepared for full-crown restorations. Wax patterns were formed leaving a 300 µm gap on one of the proximal margins. The crowns were cast and the samples were randomly divided into four groups based on the cement used. Copings were cemented using zinc phosphate cement (Fleck), Fuji Plus resin-modified glass ionomer, Panavia F2.0 resin cement, or G-Cem resin cement, according to the manufacturers' instructions. Samples were immersed in 2% methylene blue solution. After 24 hours, dye penetration was assessed under a stereomicroscope and analyzed using the respective software. Data were analyzed using ANOVA, paired t-tests, and Kruskal-Wallis, Wilcoxon, and Mann-Whitney tests.
  
  
  RESULTS
  The least microleakage occurred in the Panavia F2.0 group (closed margin, 0.18 mm; open margin, 0.64 mm) and the maximum was observed in the Fleck group (closed margin, 1.92 mm; open margin, 3.32 mm). The Fleck group displayed significantly more microleakage compared to the Fuji Plus and Panavia F2.0 groups (P < 0.001) in both closed and open margins. In open margins, differences in microleakage between the Fuji Plus and G-Cem as well as between the G-Cem and Panavia F2.0 groups were significant (P < 0.001). In closed margins, only the G-Cem group displayed significantly more microleakage as compared to the Panavia F2.0 group (P < 0.05). Paired t-test results showed significantly more microleakage in open margins compared to closed margins, except in the Fuji Plus group (P = 0.539).
  
  
  CONCLUSIONS
  Fuji Plus cement exhibited better sealing ability in closed and open margins compared to G-Cem and Fleck cements. When using G-Cem and Fleck cements for full metal ceramic restorations, clinicians should try to minimize marginal gaps in order to reduce restoration failure. In situations where there are doubts about perfect marginal adaptation, the use of Fuji Plus cement may be helpful.
authors.affiliation: Department of Dental Technology, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Eftekhar Ashtiani
authors.affiliation: Endodontics Research Center, AJA University of Medical Sciences, Tehran, IR Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Farzaneh
authors.affiliation: Department of Operative Dentistry, Dental School, International Branch of Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mohadese
authors.initials: M
authors.lastname: Azarsina
authors.affiliation: Department of Oral and Maxillofacial Surgery, Dental School, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Farzad
authors.initials: F
authors.lastname: Aghdashi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Dental School, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Nima
authors.initials: N
authors.lastname: Dehghani
authors.affiliation: Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors.forename: Aisooda
authors.initials: A
authors.lastname: Afshari
authors.affiliation: Department of Prosthetic, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Minu
authors.initials: M
authors.lastname: Mahshid
keywords: Dental Leakage; Metal Ceramic Restorations; Tooth