Marginal fit at cylinder-abutment interface before and after overcasting procedure

Authors

  • Luciana Martins Cres Moraes University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Paulo Henrique Orlato Rossetti University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Leylha Maria Nunes Rossetti University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Ana Paula Ribeiro do Vale Pedreira University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Accacio Lins do Valle University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics
  • Wellington Cardoso Bonachela University of São Paulo; Bauru School of Dentistry; Department of Prosthodontics

DOI:

https://doi.org/10.1590/S1678-77572005000400010

Keywords:

Marginal fit, Prosthetic cylinder, Dental alloys, Casting, Dental implants

Abstract

The aim of this study was to measure marginal fit at cylinder-abutment interface, before and after overcasting procedure. A hexagonal implant was fixed to a stainless steel base and a Estheticone-like abutment used during all the experiment. Before casting procedure, gold (Group I) and Ni-Cr-Be (Group II) premachined cylinders were tightened to the abutment with gold and titanium screws (in both groups), with 10Ncm and 20Ncm torque values for the same screw type. Vertical measures were taken at the light microscope (Mitutoyo 5050, Tokyo, Japan) three times in six different parts along the abutment-cylinder interface for each torque value. Cylinders were overcast with Ag-Pd (Group I) or Ni-Cr-Be (Group II) alloy. After casting, the same measures and torque values were repeated. Intragroup differences (10 or 20Ncm torque values, before and after casting) and intergroup differences (10 and 20Ncm torque values, before or after casting) were analyzed by the Paired t Test; (p<0.05). Intragroup differences were observed for G-I (gold, 20Ncm, titanium screw, p=0.044) and for G-II (Ni-Cr-Be, 10Ncm, gold screw, p=0.002). Intergroup differences only were not observed in the G-II group (Ni-Cr-Be, 10 and 20Ncm, titanium screw, p=0.534). Within the limits of this study, the following conclusions can be drawn: 1) Regardless of screw type, marginal misfit was higher for Ni-Cr-Be cylinders after casting, but within acceptable levels of fit; 2) The combination of gold cylinders with gold or titanium screws was the most effective to reduce marginal misfit; 3) Both screw types did not improve marginal fit of Ni-Cr-Be cylinders after overcastting, and 4) Although a 20Ncm torque improved marginal fit in all situations, its use is not recommended due to the increased risk of prosthesis failure. Ni-Cr-Be alloys may be successfully used in single-tooth implant restorations, with no damage to the fit between abutment and prosthetic cylinder.

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Published

2005-12-01

Issue

Section

Original Articles

How to Cite

Marginal fit at cylinder-abutment interface before and after overcasting procedure . (2005). Journal of Applied Oral Science, 13(4), 366-371. https://doi.org/10.1590/S1678-77572005000400010