Thermoplastic retention appliances. A controversial clinical reality.

AIM: The present article attempts to critically analyze the efficiency, advantages and disadvantages of thermoplastic appliances, which are widely used today to retain the outcome of an orthodontic treatment.METHOD: Collection and evaluation of original articles regarding the subject under investigation from PubMed and Cochrane Databases until January 2010.FINDINGS: Transparent appliances are the preferred appliances to retain the orthodontic treatment outcome both by patients and clinicians. They are efficient, esthetically pleasing, provide comfort and have low cost. Despite their tendency to develop open bite and unwanted occlusal contacts, the partial or continuous application and the duration of use don’t seem to comprise destabilizing elements of the treatment outcome compared to Hawley appliances.CONCLUSION: The efficiency combined with the advantages and disadvantages make the thermoplastic appliances an alternative choice to Hawley orthodontic appliances. However, evidence based research needs to establish the advantages of these retention appliances compared to other retention appliances.