title: Influence of fiber post cementation length on coronal microleakage values in vitro and finite element analysis.
abstract: OBJECTIVE
  This study aims to evaluate, the Influence of different fiber posts cementation lengths by finite element analysis (FEA) and coronal microleakage.
  
  
  METHODS
  Fifty anterior bovine teeth were sectioned to obtain roots with 16 mm length. The coronal length of the post was 6 mm for all groups, while the radicular length were varied 6, 8, 10 or 12 mm. The fiber posts surfaces were cleaned with alcohol and silanized. Then the posts were cemented using a two steps total etch-and-rinse adhesive system + conventional resin cement. Forty teeth were submitted to mechanical cycling (45°; 2.000.000 cycles; 90N; 4Hz; 37°C) and ten teeth with radicular length of 12 mm was not submitted, ser ving as c ontrol. So, the experimental design was composed by different ratios of post coronal length/post radicular length and mechanical cycling (MC): Gr1- 1/1 + MC; Gr2- 3/4 + MC; Gr3- 3/5 + MC; Gr4- 1/2 + MC. All groups were immersed in a 1% toluidine blue solution. After 24 hours, the teeth were longitudinally sectioned and the microleakage scores was given by a blind operator. Data were submitted to Kruskal-Wallis test (p = 0.05). The experimental variables were simulated in two-dimensional finite element analysis (2D-FEA). The maximum principal stress distributions were compared.
  
  
  RESULTS
  No difference was observed in microleakage values between the cycled groups, whilst the control groups showed the lowest values. FEA analysis showed similar maximum principal stress distribution between the groups.
  
  
  CONCLUSIONS
  Mechanical cycling affected the values of coronal microleakage and different cementation length generated similar values of coronal microleakage and stress distribution.
  
  
  CONCLUSIONS
  These results showed that from the microleakage point of view, more conservative cementation lengths have the same effect as longer cementation lengths.
authors.affiliation: Adjunct Professor, Department of Restorative Dentistry, Faculty of Dentistry Federal University of Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Cásar Dalmolin
authors.initials: CD
authors.lastname: Bergoli
authors.affiliation: Assistant Professor, Department of Dentistry, Faculty of Dentistry of Governador Valadares, Federal University of Juiz de Fora, Minas Gerais Brazil, e-mail: rf-carvalho@hotmail.com.
authors.forename: Rodrigo Furtado
authors.initials: RF
authors.lastname: de Carvalho
authors.affiliation: Assistant Professor, Department of Social Dentistry and Child Clinic, São Jose dos Campos Dental School, São Paulo, Brazil.
authors.forename: Ivan
authors.initials: I
authors.lastname: Balducci
authors.affiliation: Assistant Professor, Department of Dental Materials, São Paulo Dental School São Paulo, Brazil.
authors.forename: Josete Barbosa Cruz
authors.initials: JB
authors.lastname: Meira
authors.affiliation: Titular Professor, Department of Restorative Dentistry, São Josá dos Campos Dental School, São Paulo, Brazil.
authors.forename: Maria Amália Méximo
authors.initials: MA
authors.lastname: de Araújo
authors.affiliation: Titular Professor, Department of Restorative Dentistry, São Josá dos Campos Dental School, São Paulo, Brazil.
authors.forename: Marcia Carneiro
authors.initials: MC
authors.lastname: Valera
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D002484:Cementation / Q000379:methods; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry; D003763:Dental Leakage / Q000145:classification*; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis / Q000295:instrumentation; D017220:Dentin-Bonding Agents / Q000737:chemistry; D020342:Finite Element Analysis; D008422:Materials Testing; D011176:Post and Core Technique / Q000295:instrumentation*; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014048:Tolonium Chloride
chemical_list: D004396:Coloring Agents; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D019279:Resin Cements; D012821:Silanes; D014048:Tolonium Chloride