17 April 2019

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Aligners Vs fixed devices : What influence do they have on periodontal health?

Luca Levrini

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In the August 2018 issue of the journal JADA (Journal of the American Dental Association) a meta-analysis was published concerning the comparison of periodontal health in patients undergoing orthodontic treatment with orthodontic aligners compared to those undergoing treatment with fixed appliances.
Fixed orthodontic appliances can facilitate plaque build-up and compromise gum health as bindings, wires and ligatures hinder brushing and reduce natural saliva cleansing.If patients fail to maintain good oral hygiene, the accumulated plaque could cause enamel demineralization and gingivitis. In contrast, orthodontic aligners can be removed from the mouth for proper tooth brushing and prophylaxis techniques, to the extent that they are associated with a reduced risk of caries and gingivitis. Not only therefore the possibility of cleaning teeth without impediments for those who use orthodontic aligners, but also the "automatic" need to wash teeth every time they are worn during the day, three or five times.  
The published study arises from the collaboration between an Italian group (prof. Luca Levrini and Gian Marco Abbate) and a Chinese group from the University of Nanjing. This publication represents the conclusion of a series of investigations started thanks to a scholarship awarded by Align Technology in 2011 that allowed the development of the first researches of weaving and value in the relationship between gingivitis health and the application of orthodontic aligners.  

MATERIALS AND METHODS 
The authors systematically consulted conventional sources (PubMed, Web of Science, Cochrane Library and Embase) to collect studies related to this topic. After extracting the data and evaluating the quality of the research, they performed a meta-analysis and a trial sequential analysis. In particular, the authors used the Grading of Recommendations Assessment, Development and Evaluation system to evaluate the quality of the tests.  

RESULTS 
Nine studies have been included in the analysis. The results showed that orthodontic aligners are more suitable for periodontal health, including plaque index (mean difference [MD] 0.53, 95% confidence interval [CI] from 0.85 to 0.20, P 1/4 0.001), the gingival index (MD 0.27; 95% CI, 0.37 to 0.17; P <0.001) and probing depth (MD 0.35; 95% CI, from 0.67 to 0.03; P 1/4 .03), compared to fixed orthodontic devices.However, the outcome of the trial sequential analysis indicated a falsely positive meta-analysis result for probing depth. For these reasons the authors lowered the level of the tests due to the risk of prejudices and inconsistencies. 

CONCLUSIONS
Within the limits of this systematic review, orthodontic aligners are better for periodontal health than fixed appliances, but with a medium quality of evidence. For this reason, high quality RCTs are required to produce a conclusive clinical recommendation. This consideration is important because it allows orthodontic aligners to be offered to patients with an important added value, not only efficiency of the occlusal result but also health and protection of hard tissues and tooth support.  

For additional informations: 
Periodontal health during orthodontic treatment with clear aligners and fixed appliances.