Topographical analysis via metallographic analysis of plate and screw system of 2.4 mm locking system in three different cycles of autoclaving

Author(s)

Saulo Ellery Santos

• Document type: Doctoral Thesis
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2012-01-03

Examining board members

Roger William Fernandes Moreira; Bernardo Ferreira Brasileiro; Rafael Grotta Grempel; Renato Sawazaki; Glaykon Alex Vitti Stabile

• Advisor: Marcelo Marotta Araujo; Roger William Fernandes Moreira

Abstract

Stable internal fixation systems are used in bone surgery, either fractures or osteotomies, It can be submitted to multiple procedures sterilization procedures before implantation. During its use eventually the surgeon is confronted with surgical complications such as rupture of the plate during bending or breakage of screws during insertion, and this in fact occurs in clinical practice. The aim of study was to evaluate if the repeated autoclaving influences the characteristics of hardness and microscopic of plates and screws of 2.4 mm system "locking". The sample was divided into plates: group I (0) control, group II was subjected to 20 sterilization processes and group III underwent 60 procedures for autoclaving. The screws were divided equally: group I (0), group II (20) and group III (60). After preparing the sample, and were carried out hardness testing and evaluation in the microscopy of microstructure. We found a mean hardness value of 180.2, 183.8 and 171.8 Vickers respectively for the groups I, II and III of the plates (p = 0.497) and mean values of 328.8, 340.8 and 355.3 Vickers respectively for the groups I, II and III of the screws (p = 0.283). Microscopic analyzes of both screws and the plates was observed images 500x revealed that the microstructure of the material, with granules in different conformations in accordance with the margin analyzed, there are still forming twinned, especially in the inset, which may be due to pressure force / shear during the machining process, but no differences between groups was observed. Based on the results obtained in all samples, it was observed that the repeated autoclaving does not significantly alter the characteristics of the material hardness and microscopic examination (AU)

• FAPESP's process: 10/17733-2 - CHEMICAL AND TOPOGRAPHICAL ANALYSIS BY METALLOGRAPHIC ANALYSIS AND SCANNING ELECTRON MICROSCOPY (SEM)OF LOCKING PLATE 2.4 mm SYSTEM IN THREE DIFFERENT AUTOCLAVING CYCLES
• Grantee: Saulo Ellery Santos
• Support Opportunities: Scholarships in Brazil - Doctorate