Effect of Ultrasound and Gingival Fibroblasts on Periodontal Defect Repair

Objectives: Periodontitis is a chronic inflammatory disease of periodontal tissues that can lead to tooth loss if left untreated. Several treatment modalities have been reported in the literature to regenerate periodontal tissues like graft surgeries, guided tissue regeneration, and growth factors. Low-intensity pulsed ultrasound (LIPUS) has been used in orthopedic surgery and orthodontics to accelerate fracture healing and tooth movement, respectively. The present study evaluated the effect of LIPUS alone and in combination with gingival fibroblasts on graft surgery in periodontal tissue in dogs.
Methods: Third and fourth premolars in each quadrant of three Beagle dogs were randomly assigned to four groups: positive control (collagen sponge), osteogenically induced gingival fibroblasts (OIGF), LIPUS, and LIPUS+OIGF. A fourth dog was treated as a negative control. 6mm bone defect was created on the premolars and a sterile silk suture was ligated. The suture was removed after 45 days, during which dogs were fed a soft sweetened diet. After 90 days, the chronic defect was clinically evident, and each premolar was treated according to the assigned group. For OIGF, gingival tissue was removed from interdental papilla and osteogenically induced using a lab-optimized medium. The dogs were euthanized after 28 days. The maxilla and mandible were sectioned and scanned using SkyScan. Parameters evaluated were bone volume (BV), bone volume fraction (BVTV), and trabecular thickness (TbTh), separation (TbSep), and number (TbN). One-way ANOVA analysis was conducted using SPSS20.0.
Results: There was a statistically significant difference between the groups for all parameters except TbSep (p=0.085). LIPUS and LIPUS+OIGF showed a significant increase in BV, TbTh, and TbN as compared to positive and negative control groups.
Conclusions: LIPUS and LIPUS+OIGF increased the mechanical strength of bone by increasing the volume, thickness, and number of new alveolar bone trabeculae. Therefore, LIPUS has the potential to promote bone graft healing in periodontal surgery.