Randomized split-mouth clinical trial comparing osteoblastic activity and osteogenic potential of autogenous particle harvesting during implant surgery without irrigation and with irrigation.

OBJECTIVE: To compare the osteoblastic activity and osteogenic potential of autogenous particle harvesting during implant surgery using low-speed drilling without irrigation and high-speed drilling with irrigation. MATERIALS AND METHODS: Thirty patients with bilateral missing teeth of 3.6 and 4.6 were randomized into two groups (Group 1: low-speed drilling without irrigation and Group 2: high-speed drilling with irrigation) and 60 single dental implants were placed. The temperature at the tip of each drill was recorded and the harvested bone was weighed; particle size and Ca and P levels were also analyzed. After osteoblast culture, cell viability, cell cycle assay, cell migration, vascular endothelial growth factor (VEGF) concentration, and mineralized nodule formation were assessed. RESULTS: Although the temperature of the drills was slightly higher in Group 1, no statistically significant differences were observed (p ≤ 0.05); however, the amount of harvested bone was higher (p < 0.001) and the size of the particles was higher (p = 0.019). In relation to osteoblastic activity and osteogenic potential, higher cell proliferation, higher number of cells in G2/M and S phases, higher cell migration capacity, higher VEGF concentration, and higher amount of mineralized nodule formation were observed in Group 1. CONCLUSIONS: Low-speed drilling without irrigation does not result in a significant increase in bone temperature compared to conventional drilling. However, a greater amount of bone is obtained; in addition, osteoblastic activity and osteogenic potential are higher with this technique, but further clinical studies are necessary.

Zoledronic acid and irradiation in oral squamous cell carcinoma.

OBJECTIVE: This in vitro study evaluated cytotoxicity and cell migration effects of zoledronic acid and irradiation upon oral squamous cell carcinoma. MATERIALS AND METHODS: Zoledronic acid was administrated at doses of 10, 25, 50, and 100 µM to PE/CA-PJ15 oral squamous cell carcinoma cultures, irradiated with different doses (0, 5, 15, and 30 Gy), followed by evaluation of the effects on cell viability. Cell migration capacity was studied after 24- and 72-h incubation. RESULTS: At 24 h, the 100 µM concentration of zoledronic acid combined with 15 Gy irradiation caused the greatest decrease in cell viability. At 72 h, statistically significant decreases in cell viability were found with all concentrations of zoledronic acid with or without irradiation: 0 Gy (P < 0.001), 5 Gy (P < 0.001), 15 Gy (P < 0.001), and 30 Gy (P < 0.001). 50 µM and 100 µM doses of zoledronic acid combined with 5 Gy irradiation yielded the greatest decrease in cell migration capacity. CONCLUSIONS: Zoledronic acid increases cytotoxic activity in the PE/CA-PJ15 cell line and reduces cell migration capacity. These findings suggest that combination therapy using biphosphates and radiation may offer a promising therapy.