Effect of systemic intermittent administration of human parathyroid hormone (rhPTH[1-34]) on the resistance to reverse torque in rabbit tibiae.

The aim of this study was to evaluate the effect of intermittent administration of human parathyroid hormone [rhPTH (1-34)] on the removal torque of implants placed in rabbit tibiae. Twenty male New Zealand rabbits were submitted to implant surgery. Each animal received one machined screw-type implant (3.75 mm diameter x 8 mm length) in the proximal metaphysis of the right tibia. The rabbits were then divided into 2 groups: the test group (n = 10) received 6 microg/kg of rhPTH (1-34) subcutaneously in the dorsal region 3 days a week, and the control group (n = 10) received placebo. Removal torque was performed at 28 and 56 days after implant placement for both groups. The mean removal torque values at 28 days were 37.0 +/- 4.36 Ncm and 47.4 +/- 6.77 Ncm for control and test groups respectively (P < .05). At 56 days the reverse torque was 45.8 +/- 3.96 Ncm for the control group and 55.8 +/- 2.86 Ncm for the test group, indicating that the removal torque was significantly higher in the test groups (P < .05). These results demonstrated that intermittent treatment with rhPTH (1-34) enhanced the removal torque of implants in rabbit tibiae.

Effect of anesthetics containing lidocaine and epinephrine on cardiovascular changes during dental implant surgery.

The purpose of this study was to evaluate cardiovascular changes during dental implant surgery using 2% lidocaine with 1:80 000 epinephrine. Eleven normotensive subjects, ranging from 18 to 56 years, were selected to undergo dental implant surgery in the jaw. They were monitored in the pre-, intra-, and postsurgical periods by continuous noninvasive automatic arterial pressure and cardiac frequency measurements taken every 2 minutes. Parameter scores were obtained for the following phases: P1, 15 minutes during preparation of the patient (control period); P2, before anesthesia; P3, immediately after anesthesia; P4, 2 minutes into anesthesia; P5, during incision and detachment; P6, during perforation; P7, during implant placement; P8, during suturing; P9, on completion; and P10, 10 minutes after termination. Individualized statistical analysis for each group during the pre-, intra-, and postoperative periods were performed by analysis of variance. The greatest variations in systolic pressure were increases of 2.29% during phase P2 and 2.59% in phase P5. Diastolic pressure decreased during phase P6 (-2.58%) and increased in P10 (3.27%). The greatest changes in heart rate occurred in phase P10 (-3.24%). There were no statistically significant changes among the evaluated phases (P > .05). In conclusion, there were no changes in the analyzed cardiocirculatory parameters during dental implant surgery (systolic, diastolic, and mean arterial blood pressures and heart rate) in normotensive subjects anesthetized with 2% lidocaine with epinephrine 1:80000.