OBJECTIVE: To investigate the mechanical behavior of cement-local anesthetic combinations in vitro. METHODS: Two bone cements were tested (Simplex® and Biomecânica®) with two anesthetic drugs (lidocaine and bupivacaine). Anesthetic drugs were added in powder form. The authors compared six groups based on the association between the cement and the drugs. Two grams of anesthetic were mixed with 40 g of acrylic cement powder. 60 prismatic molds were made, measuring 5 x 120 x 30 mm (n = 30) and 5 x 60 x 30 mm (n = 30). The molds were tested on a pendulum impact resistance apparatus. Statistical analysis was performed to verify the effect of bone cement (Simplex® and Biomecânica®) and the medication (lidocaine, bupivacaine, and no combination) on the strength of the molds, with a level of significance alpha = 5%. RESULTS: Statistical comparison showed a significant influence of the medication on bone strength (p = 0.0001). Tukey multiple comparison test demonstrated better strength with bupivacaine. CONCLUSION: Cement-bone combination does not harm the strength of the cement itself.
Bone cements; Polymethyl methacrylate; Lidocaine; Bupivacaine
