Drinking Coffee Accelerates Orthodontic Tooth Movement
Posted on July 25, 2014
Atthe 92nd General Session & Exhibition of the International Association for Dental Research (IADR), Y. Li, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, presented a study titled “Drinking Coffee Accelerates Orthodontic Tooth Movement through Enhancing Osteoclastogenesis.”
Caffeine, the kernel component of coffee, has been shown to affect bone metabolism through regulation of osteoclast, osteoblast, and calcium balance. This study aimed to investigate the effects of drinking coffee on orthodontic tooth movement (OTM).
In this study 30 male Wistar rats were randomly divided into the regular OTM (rO) and coffee+OTM (cO) groups. At 5 weeks of age, the cO rats began receiving daily intragastric administration of coffee according to body weight. At 13 weeks of age, the left maxillary first molar of the both groups was moved mesially with a nickel-titanium coil spring. After 3 weeks, the OTM amount was measured. The alveolar bone mineral density (BMD) was analyzed with micro-computed tomography (μCT).
Immunohistochemical staining was done for TRAP and RANKL expression in the periodontium. The periodontal ligament (PDL) tissue model was established through 3D culturing human PDL cells in poly lactic-co-glycolic acid (PLGA) scaffolds. Four groups were established with different intervention regimes—normal culture (control), caffeine (0.1 Mm), mechanical force (25 g/cm2), caffeine (0.1 Mm) + mechanical force (25 g/cm2). After a 6-hour intervention, real-time PCR and ELISA were performed to investigate COX-2/PGE2and RANKL expression.
Compared with rO, the cO rats had significantly larger tooth movement. Meanwhile, the cO had significantly lower alveolar BMD, indicating decreased bone mineralization. Moreover, in the compression periodontium, the cO had significantly more TRAP+ osteoclasts and higher RANKL expression, indicating increased osteoclastogenesis. When treated alone, mechanical force significantly up-regulated COX-2/PGE2 and RANKL expression in the PDL tissue model whereas caffeine didn’t; however the caffeine+mechanical force group had significantly larger elevation of COX-2/PGE2 and RANKL expression, compared with the mechanical force alone group.
This study found that drinking coffee accelerates OTM, probably through the effects of caffeine on osteoclastogenesis enhancement via RANKL elevation. This research was supported by the National Nature Science Foundation of China.