title: Effect of tooth preparation on microleakage of stainless steel crowns placed on primary mandibular first molars with reduced mesiodistal dimension.
abstract: OBJECTIVE
  Incomplete adaptation of stainless steel crown margins leads to microleakage. The aim of this study was to evaluate the effect of tooth preparation on microleakage of stainless steel crowns (SSCs) placed on mesiodistally reduced primary mandibular first molars.
  
  
  METHODS
  In this In vitro study, 60 primary mandibular first molars with reduced mesiodistal dimension were selected. Pulp cavities were filled with amalgam and occlusal surfaces were reduced. The samples were randomly divided into two groups (groups P and BLP). Standard preparation was done in group P with only proximal reduction. In group BLP, after reducing the proximal undercuts, buccal and lingual surfaces were slightly reduced. Occlusal one-third of the buccal surfaces was beveled in both groups. Then, the SSCs of the primary maxillary and mandibular first molars were fitted and cemented in P and BLP groups, respectively. After immersing the samples into deionized water, thermo-cycling, and immersion in 2% basic fuchsin, the samples were sectioned buccolingually. The mesial halves were evaluated microscopically for microleakage in both buccal and lingual margins. Data were analyzed using Mann-Whitney U test in SPSS 19 at the significant level of 0.05.
  
  
  RESULTS
  There was a significant difference in microleakage of the buccal margin (P=0.003); whereas, the difference observed in the lingual margin was not significant (P=0.54).
  
  
  CONCLUSIONS
  We suggest reduction of buccal and lingual surfaces of mesiodistally reduced primary mandibular first molars and placing lower (mandibular) crowns.
authors.affiliation: Assistant Professor, Children and Adolescent Health Research Center, Department of Pediatric Dentistry, Faculty of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Ramazani
authors.affiliation: Dentist, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Mina
authors.initials: M
authors.lastname: Ranjbar
keywords: Crown; Leakage; Primary teeth; Stainless steel