Abstract
ObjectivesThe purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders. Material and MethodsThirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12% chlorhexidine gluconate (Periogard®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher's test at 5% significance level. ResultsThe analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups. Conclusion: Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12% chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ.
Highlights
The oral environment is favorable to metal biodegradation due to its chemical, thermal, microbiological and enzymatic conditions[19]
This study evaluated in situ the corrosion of the metallic components of Haas expanders by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS)
For construction of the Haas expanders, the SHUPDQHQW ¿UVW PRODUV ZHUH EDQGHG DQG WKH PHWDOOLF EDQGV ZHUH VLOYHU ZHOGHG 'HQWDO 0RUHOOL 6RURFDED SP, Brazil) to 0.9 mm stainless steel orthodontic ZLUHV 'HQWDXUXP,VSULQJHQ *HUPDQ\ 7KH DFWLYH FRPSRQHQW ZDV DQ PP H[SDQGLQJ VFUHZ (Dental Morelli, Sorocaba, SP, Brazil)
Summary
The oral environment is favorable to metal biodegradation due to its chemical, thermal, microbiological and enzymatic conditions[19]. When in FRQWDFW ZLWK VDOLYD DQG DFLGEDVLF IRRGV DW GLIIHUHQW temperatures, the metal components of orthodontic appliances may undergo corrosion[2]. ZLWK ¿[HG DSSOLDQFHV FDXVHV VSHFL¿F DOWHUDWLRQV LQ the oral cavity, including decrease of pH, increase RI GHQWDO ELR¿OP DFFXPXODWLRQ26 and elevation of the salivary microbial levels[6,27] ZKLFK DUH IDYRUDEOH conditions to the occurrence of corrosion. Corrosion of orthodontic appliances may have serious clinical implications that range from loss of dimension RI WKH DSSOLDQFH¶V FRPSRQHQWV ZKLFK UHVXOWV LQ DSSOLFDWLRQ RI ORZHU IRUFH WR WKH WHHWK XS WR SRVVLEOH. The released metallic ions PD\ JHW LQ FRQWDFW ZLWK FHOOV DQG WLVVXHV LQ WKH contiguous environment or pervade throughout the body. Absorption of toxic products released during corrosion of metallic orthodontic components by body tissues is undesirable[11,14,28]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
