Variation of gingival crevicular fluid volume in early orthodontic tooth movement with clear aligner: A pilot study

Objectives: The objective of this pilot study was to evaluate the crevicular fluid volume (GCF) increase from a quantitative point of view in the first 8 hours of clear aligner treatment. Then, its variation and the amount of Orthodontic Tooth Movement (OTM) obtained with clear aligners was evaluated considering two different protocols, one of 20 h and one of 12 h. Material and Methods: A total of 10 healthy, adult patients were selected to participate in a split-mouth study where an orthodontic treatment with clear aligners was planned. Vestibular crown uncontrolled tipping was planned for upper lateral-posterior sectors. At 0H (baseline), and every hour for the first 8 hours of use, three GCF samples were collected. Then, all patients were asked to wear one random half of the upper aligner for 12 hours per day (Group 1) and the other half for 20 hours per day (Group 2). The GCF samples were measured using the Periotron 8000 device to quantify inflammation. Then, the amount of movement obtained was calculated by considering the FA point shift in mm with Geomagic X Control Software. Results: No differences were found between the extent of inflammation in terms of GCF volume and hours of intermittent force application (group 1 vs group 2). Conclusion: The amount of GCF assessed through Periotron 8000 increases significantly from the moment forces are applied through clear aligners. Considering the limitations of the following pilot study, it would appear that the GCF amount is directly related to the amount of movement obtained.