Anesthetic efficacy of liposomal prilocaine in maxillary infiltration anesthesia.

Animal studies have shown that liposome encapsulation increases prilocaine anesthetic efficacy. This randomized, blind, crossover, three-period study evaluated the anesthetic efficacy of liposome-encapsulated 3% prilocaine, compared to 3% plain prilocaine and 3% prilocaine with 0.03IU/mL felypressin, after a 1.8-mL infiltration in the buccal sulcus of the maxillary right canine, in 32 volunteers. Anesthesia success, onset, and duration of pulpal and gingival anesthesia in the lateral incisor, and canine and first premolar were evaluated. Injection pain was assessed by a visual analog scale (VAS). Results were submitted to Kruskal-Wallis (onset and duration of pulpal anesthesia), Tukey (VAS), Friedman (duration of gingival anesthesia), and log-rank and McNemar tests (anesthesia success) (α = 5%). Liposomal prilocaine did not differ from plain prilocaine (P > 0.05), but presented lower anesthesia success and duration for canine, premolar, and gingival anesthesia (P < 0.05) than prilocaine with felypressin. Liposomal prilocaine did not differ from the other formulations concerning onset and anesthesia success for the lateral incisor (p > 0.05); plain prilocaine presented lower success rates and slower onset of anesthesia for this tooth, in comparison to prilocaine with felypressin (P < 0.05). No differences were observed among the formulations in relation to duration of anesthesia for lateral incisor, VAS scores, and onset of gingival and pulpal anesthesia for the canine and premolar (P > 0.05). In conclusion, liposomal prilocaine presents similar anesthetic efficacy in relation to plain prilocaine and lower efficacy, in comparison to prilocaine with felypressin in maxillary infiltration. Prilocaine does not seem to benefit from liposomal encapsulation.

Standardized Arrabidaea chica Extract Shows Cytoprotective Effects in Zoledronic Acid-Treated Fibroblasts and Osteoblasts.

INTRODUCTION: Osteonecrosis of the jaw is a condition associated with intraoral ulceration and bone necrosis induced by antiresorptive medications, such as zoledronic acid, a bisphosphonate. Previous data on Arrabidaea chica (H&B.) Verlot wound healing activity prompted the study reported herein on A. chica standardized hydro alcoholic extract in vitro cytoprotective activity data on epithelial and osteoblastic cells exposed to zoledronic acid (ZA). METHODS: Primary human gingival fibroblasts and murine pre-osteoblasts were treated with ZA 10 µM together with 5 or 10 µg.mL-1 A. chica extract for 24h and 48 h. At both times, cells were submitted to viability assay and caspase 3/7 activation evaluation. Statistical analysis used one-way ANOVA and p=0.05. RESULTS: In cell viability assay, a drastic damage effect of ZA appeared after 48 h in both epithelial (55.8%) and pre-osteoblastic cells (39.7%). When treated with ZA in combination with A. chica extract, cells showed higher viability values: 74.1%-82.3% for fibroblasts and 66% for pre-osteoblasts. Furthermore, the combined treatment presented lower caspase 3/7 activation in fibroblasts and pre-osteoblasts. CONCLUSION: At low concentrations, A. chica extract showed promising cytoprotective effects against ZA-induced damage actions; however, further in vitro and in vivo studies are required to establish the mechanism of action.