Effects of ovariectomy on periodontal tissues following tooth replantation.

OBJECTIVES: The aim of the study was to analyze the effects of ovariectomy on periodontal tissues following immediate tooth replantation by histomorphometric, immunohistochemistry, and µCT analysis. MATERIALS AND METHODS: Eighty wistar rats (Rattus norvegicus albinos) with normal estrous cycles were randomly divided into two groups: ovariectomized (OVX) and Sham. Two months after surgery, the rats' upper right incisor was extracted followed by immediate reimplantation. The animals were sacrificed after 28, 45, and 60 days healing time. Histomorphometric and immunohistochemical analysis were performed by evaluation of PCNA and TRAP straining. RESULTS: The periodontal ligament was reinserted into the bone and cementum in the both groups. The immunohistochemical analysis revealed PCNA positive cells on the periodontal ligament in both groups at 28 days. Root resorption was noted at 45 days with immunoreactive cells for TRAP present in bone and tooth surface however no statistical differences between the groups were noticed. Histomorphometric analysis showed significant difference between groups in the periodontal ligament and root resorption parameters for the sub-items: intensity of chronic inflammatory infiltrate at 60 days (p<0.01), the organization of the periodontal ligament at 28 days (p<0.05), depth of root resorption at 45 days (p<0.05) and at 60 days (p<0.001). The µCT analysis showed multiple areas of bone resorption in association with OVX at 28 and 60 days with no significant differences between times in vivo. CONCLUSION: The ovariectomy did not have significant influence in periodontal tissue parameters following tooth reimplantation.

Immediate tooth replantation in rats: effect of systemic antibiotic therapy with amoxicillin and tetracycline.

OBJECTIVES: The aim of this study was to evaluate the influence of systemic administration of antibiotics (amoxicillin and tetracycline) at the different phases of the repair process (7, 15, 30 days) in immediate rat tooth replantation. MATERIALS AND METHODS: Ninety rats had their incisors extracted and stored in saline for 5 min. Next, the teeth were replanted, and the animals were assigned to three groups according to the antibiotic administered by oral gavage: control group, amoxycillin group, and tetracycline group. Euthanasia was performed at 7, 15, and 30 days after replantation. RESULTS: Regardless of the evaluation period, the connective tissue underlying the epithelial attachment and the periodontal ligament showed statistically significant difference relative to the acute inflammatory infiltrate, which was more intense in the control group followed by the tetracycline group. CONCLUSION: These results point to the fact that systemic antibiotic therapy (SAT) in immediate tooth replantation is beneficial to pulpal and periodontal ligament repair and that amoxycillin is an excellent option. CLINICAL RELEVANCE: There is a lack of randomized studies assessing how the use of systemic antibiotics could influence tooth healing after immediate replantation.

Stress distribution in delayed replanted teeth splinted with different orthodontic wires: a three-dimensional finite element analysis.

AIM: The aim was to evaluate the biomechanical behavior of the supporting bony structures of replanted teeth and the periodontal ligament (PDL) of adjacent teeth when orthodontic wires with different mechanical properties are applied, with three-dimensional finite element analysis. MATERIALS AND METHODS: Based on tomographic and microtomographic data, a three-dimensional model of the anterior maxilla with the corresponding teeth (tooth 13-tooth 23) was generated to simulate avulsion and replantation of the tooth 21. The teeth were splinted with orthodontic wire (Ø 0.8 mm) and composite resin. The elastic modulus of the three orthodontic wires used, that is, steel wire (FA), titanium-molybdenum wire (FTM), and nitinol wire (FN) were 200 GPa, 84 GPa, and 52 GPa, respectively. An oblique load (100 N) was applied at an angle of 45° on the incisal edge of the replanted tooth and was analyzed using Ansys Workbench software. The maximum (σmax) and minimum (σmin) principal stresses generated in the PDL, cortical and alveolar bones, and the modified von Mises (σvM) values for the orthodontic wires were obtained. RESULTS: With regard to the cortical bone and PDL, the highest σmin and σmax values for FTM, FN, and FA were checked. With regard to the alveolar bone, σmax and σmin values were highest for FA, followed by FTM and FN. The σvM values of the orthodontic wires followed the order of rigidity of the alloys, that is, FA > FTM > FN. CONCLUSION: The biomechanical behavior of the analyzed structures with regard to all the three patterns of flexibility was similar.