Locally Inhibition of Orthodontic Relapse by Injection of Carbonated Hydroxy Apatite-Advanced Platelet Rich Fibrin in a Rabbit Model

Abstract

Relapse is considered a significant failure after orthodontic treatment. In response to relapse, RANKL expressions will increase, while OPG expressions will decrease. CHA is thought to be one of an ideal candidate for enhancing bone formation. Moreover, a-PRF is a source high levels of growth factors that play a central role in the bone remodeling. This research was intended to investigate the effect of hydrogel CHA-aPRF in preventing relapse. Hydrogel-CHA was initially designed, with its degradation profile and FTIR (Fourie’s Transform Infrared) spectra were investigated as the basis to find out optimum formulation before incorporated with aPRF. Hydrogel-CHA microspheres were prepared in 3 different compositions: those were encoded 30-CHA, 40-CHA, and 50-CHA. After the hydrogel formulation and characterization were completed, 10 mL blood samples were collected, then centrifuged at 1500 rpm for 14 min. At the end of the centrifugation process, the aPRF clot was isolated and then pressed to obtain their releasate. The releasate aPRF was then loaded into the best formulation candidate of hydrogel CHA. The hydrogel incorporated aPRF was then gently injected on the mesial side of incisor gingival sulcus of the rabbit after orthodontic tooth movement. The FTIR analysis showed that carbonated apatite was successfully developed during the fabrication process of hydrogel-CHA microspheres. It was also known that degradation profile of 30-CHA was considered ideal compared to the other compositions. The application of CHA-aPRF (group C) was proven to significantly prevent relapse, indicated by lowest percentage of relapse 21 days after debonding (29.95±3.91%) compared to control group. Furthermore, it has been found that expressions of RANKL were significantly lowest (p<0.05) in group C on day 0, 3, and 7, while OPG expressions showed significantly highest (p<0.05) in group C on day 14 and 21 after debonding. These results indicate that incorporation of hydrogel-CHA has potential effect to enhance alveolar bone remodeling and prevent orthodontic relapse by stimulates OPG expression and suppresses RANKL expression.

Effect of Carbonate Apatite Hydrogel-Advanced Platelet-Rich Fibrin Injection on Osteoblastogenesis during Orthodontic Relapse in Rabbits

“…An animal study revealed that osteoclastogenesis performs an important role in relapse. 3 Osteoblastogenesis is believed to counteract the osteoclastogenesis. 4 Osteoblasts, the principal mononucleated cells of bone tissue, are responsible for alveolar bone formation and the stability of the moved tooth.…”

“…Increases in OPG expression level indicate the enhancement of differentiated osteoblasts and is related to lower relapse rates. 3 Advanced-PRF (aPRF) is a novel PRF modification form prepared by reducing the centrifugation speed and extending the centrifugation time of the original fibrin. This adjustment yields higher platelet concentrations, which is the result of fewer cells moving to the bottom of the tubes during centrifugation, and a greater amount of proteins, including platelets, left in the higher part of the tubes where the clot is isolated.…”

Postorthodontic Relapse Prevention by Administration of Grape Seed (Vitis vinifera) Extract Containing Cyanidine in Rats

“…4 During orthodontic relapse, there is an increase in RANKL levels but a decrease in osteoprotegerin (OPG) levels. 5 Eur J Dent 2019;13:629-634…”

<p>Wheat seeds can delay orthodontic tooth movement by blocking osteoclastogenesis in rats</p>

“…Long-term stability post-orthodontic treatment is controversial among orthodontists 1. Uncompleted alveolar bone remodeling is one of the etiological factors of orthodontic relapse 2.…”

“…On the other hand, osteoprotegerin (OPG) expressed by osteoblast will inhibit RANK and RANKL binding to prevent osteoclast differentiation 3. During a relapse, RANKL levels will elevate, while OPG levels will decrease 1…”