ABSTRACT
BACKGROUND: Immunosuppressive agents may induce severe changes on bone metabolism and may impair the osseointegration process during the implant healing. No data are available concerning the influence of cyclosporin A on dental implants previously integrated to the bone. The aim of this study was to evaluate the influence of cyclosporin A administration on the mechanical retention of bone previously integrated to dental implants. METHODS: Eighteen female New Zealand rabbits were submitted to an implant surgery. Each animal received one commercial dental implant of 10 x 3.75 mm. After 12 weeks of an undisturbed healing period, six animals were randomly sacrificed and the removal torque test was performed (group A). In addition, six animals were submitted to a daily injection of cyclosporin A in a dosage of 10 mg/kg (group C), and six animals received saline solution as a control (group B). After 12 weeks of cyclosporin A administration, groups B and C were sacrificed and submitted to a removal torque test in which higher values can be interpreted as higher mechanical bone retention to the implant surface or higher osseointegration. RESULTS: The removal torque results were 30.5 (+/-9.8) Ncm for group A, 50.17 (+/-17.5) Ncm for group B, and 26 (+/-7.8) Ncm for group C. The statistical analysis showed significant differences between groups A and B (P <0.05) and groups B and C (P <0.01). CONCLUSION: Cyclosporin A administration may impair the mechanical retention of dental implants previously integrated to the bone.
Subject(s)
Cyclosporine/therapeutic use , Dental Implants , Dental Prosthesis Retention , Immunosuppressive Agents/therapeutic use , Osseointegration/drug effects , Animals , Dental Implantation, Endosseous , Dental Stress Analysis , Female , Rabbits , Random Allocation , Statistics, Nonparametric , Tibia/surgery , TorqueABSTRACT
BACKGROUND: Immunosuppressive agents may induce severe changes on bone metabolism. The purpose of the present study was to evaluate the influence of the administration of cyclosporin A (CsA) on the bone tissue around titanium implants. METHODS: Eighteen New Zealand rabbits were randomly divided into 2 groups of 9 each. The test group (CsA) received daily subcutaneous injection of CsA (10 mg/kg body weight) and the control group (CTL) received saline solution by the same administration route. Three days after therapy began, 2 implants (7.0 mm long and 3.75 mm in diameter) were inserted bilaterally at the region of the tibial methaphysis. After 4, 8, and 12 weeks the animals were sacrificed and biomechanical tests and histometrical procedures, consisting of the determination of the percentages of bone-implant contact and bone area within the limits of the implant threads, were performed. RESULTS: Intergroup analysis showed that the removal torque and the percentage of bone contact with the implant surface for CsA group were significantly lower than those of the CTL group at 12 weeks (28.5 and 39.2 N cm, P = 0.01; 7.76% and 18.52%, P = 0.02, respectively). CONCLUSION: The data from the present study suggest that long-term administration of cyclosporin A may negatively influence bone healing around dental implants.
Subject(s)
Bone and Bones/drug effects , Cyclosporine/therapeutic use , Dental Implants , Immunosuppressive Agents/therapeutic use , Titanium , Animals , Biomechanical Phenomena , Bone and Bones/pathology , Bone and Bones/physiopathology , Injections, Subcutaneous , Osseointegration , Rabbits , Random Allocation , Sodium Chloride , Statistics, Nonparametric , Surface Properties , Tibia , Time Factors , Titanium/chemistry , Torque , Wound Healing/drug effectsABSTRACT
The oral rehabilitation by dental implants in patients with diabetes remains a controversial issue. The aim of this study was to evaluate the influence of diabetes mellitus and insulin therapy on the bone healing around dental implants using torque removal. Twenty-seven rabbits were randomly divided into 3 groups with 9 animals each: control (C) group, induced diabetic (D) group, and insulin-treated diabetic (ITD) group (10 U/day). After 1 week, one implant was inserted at the tibial metaphysis of the animals. The glucose levels were periodically evaluated through the glucose-oxidase enzymatic method. The animals were killed at 4, 8, and 12 weeks after surgery and the biomechanical test was performed using a torque manometer. Statistically significant differences regarding the removal torque of the implant could not be found at 4 weeks (P = 0.2) among groups. Group C showed statistically higher values than groups D and ITD at the experimental periods of 8 (P = 0.0001 and P = 0.0002, respectively) and 12 weeks (P = 0.0053 and P = 0.001, respectively). There were no statistical differences between D and ITD groups in any of the experimental periods. Diabetes mellitus has negatively influenced the mechanical retention of implants placed at the tibial metaphysis of rabbits. Therapy with insulin did not induce any changes.
