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International Journal of Dentistry
Volume 2012, Article ID 720538, 5 pages
Research Article

Laser Welding and Syncristallization Techniques Comparison: In Vitro Study

1Department of Dental Sciences, Faculty of Medicine, University of Liège, 4000 Liège, Belgium
2Oral Medicine and Laser-Assisted Surgery Unit, Dental School, Faculty of Medicine and Surgery, University of Parma, 12-143121 Parma, Italy

Received 11 March 2012; Accepted 12 May 2012

Academic Editor: H. S. Loh

Copyright © 2012 C. Fornaini et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. Laser welding was first reported in 1967 and for many years it has been used in dental laboratories with several advantages versus the conventional technique. Authors described, in previous works, the possibility of using also chair-side Nd : YAG laser device (Fotona Fidelis III,  nm) for welding metallic parts of prosthetic appliances directly in the dental office, extra- and also intra-orally. Syncristallisation is a soldering technique based on the creation of an electric arc between two electrodes and used to connect implants to bars intra-orally. Aim. The aim of this study was to compare two different laser welding devices with a soldering machine, all of these used in prosthetic dentistry. Material and Methods. In-lab Nd : YAG laser welding (group A = 12 samples), chair-side Nd : YAG laser welding (group B = 12 samples), and electrowelder (group C = 12 samples) were used. The tests were performed on 36 CrCoMo plates and the analysis consisted in evaluation, by microscopic observation, of the number of fissures in welded areas of groups A and B and in measurement of the welding strength in all the groups. The results were statistically analysed by means of one-way ANOVA and Tukey-Kramer multiple comparison tests. Results. The means and standard deviations for the number of fissures in welded areas were for group A and for group B. The difference was statistical significant ( at the level 95%). On the other hand, the means and standard deviations for the traction tests were  N for group A,  N for group B, and  N for group C. The difference was statistical significant ( at the level 95%). Conclusion. The joint obtained by welding devices had a significant higher strength compared with that obtained by the electrowelder, and the comparison between the two laser devices used demonstrated that the chair-side Nd : YAG, even giving a lower strength to the joints, produced the lowest number of fissures in the welded area.