Are sectioning and soldering of short-span implant-supported prostheses necessary procedures?

• Published in: Acta odontológica latinoamericana Vol. 24; no. 1; pp. 21 - 28
• Main Authors: Bianchini, Marco A, Souza, João G O, Souza, Dircilene C, Magini, Ricardo S, Benfatti, Cesar A M, Cardoso, Antonio C
• Format: Journal Article
• Language: English
• Published: Argentina Sociedad Argentina de Investigación Odontológica 2011
• Subjects: Dental Prosthesis, Implant-Supported - methods; Dental Soldering; Dentistry; DENTISTRY, ORAL SURGERY & MEDICINE; Soldagem em odontologia; Protese dentaria fixada por implante; Dental prosthesis; Adaptacao marginal dentaria; Implant-supported; Dental marginal adaptation; Dental soldering
• ISSN: 0326-4815; 1852-4834

The aim of this study was to evaluate the fit between dental abutments and the metal framework of a 3-unit fixed prosthesis screwed to two implants to determine whether sectioning and soldering of the framework are in fact necessary procedures. The study was based on a model of a metal framework of a 3-unit prosthesis screwed to two implants. A total of 18 metal frameworks were constructed and divided into 3 groups: (1) NS group - each framework was cast in one piece and not sectioned; (2) CS group - the components of each sectioned framework were joined by conventional soldering; and (3) LW group - the components of each sectioned framework were joined by laser welding. The control group consisted of six silver-palladium alloy copings that were not cast together. Two analyses were mperformed: in the first analysis, the framework was screwed only to the first abutment, and in the second analysis, the framework was screwed to both abutments. The prosthetic fit was assessed at a single point using a measuring microscope (Measurescope, Nikon, Japan) and the marginal gap was measured in micrometers. Statistical analysis was performed using analysis of variance (ANOVA), Scheffe's test, Student's t-test, and Mann-Whitney U test. The NS group had larger marginal gaps than the other groups (p<0.01), while the CS and LW groups had a similar degree of misfit with no significant difference between them. The results revealed that, in the case of short-span 3-unit fixed prostheses, the framework should be sectioned and soldered or welded to prevent or reduce marginal gaps between the metal framework and dental abutments.