Enhanced Bone Bonding to Nanotextured Implant Surfaces at a Short Healing Period: A Biomechanical Tensile Testing in the Rat Femur.

PURPOSE: To compare the bone bonding capabilities of 2 different surface treatments at an early healing period. Titanium alloy (Ti6Al4V) custom-made rectangular plates (1.4 × 2.4 × 4 mm) were either dual acid etched (Ti6Al4V-DAE) or DAE/nanotextured blasted (Ti6Al4V-NTB). MATERIALS AND METHODS: Implants were placed in the distal femurs of 10 Wistar rats and were allowed to heal for 9 days. After euthanasia, the bone immediately proximal and distal to the implant was removed to test the bone bonding force with a universal testing machine. Ultrastructure of the bone/implant interface was assessed by scanning electron microscopy. RESULTS: Ti6Al4V-NTB samples exhibited significantly greater bond strength than Ti6Al4V-DAE samples. Morphologically, the Ti6Al4V-NTB surfaces presented intimate interaction with bone, whereas little interaction between the Ti6Al4V-DAE surface and bone was observed. CONCLUSION: The results of this study indicated a significant increase in bone bonding for the DAE/nanotextured blasted surface, which is suggested to be the outcome of the nanotexturing.

An alternative to nerve repair using an antioxidant compound: a histological study in rats.

The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site. The animals with nerve injury (Ctl2 and Exp group) were sacrificed at 15 and 30 days post-operatively. The histological analysis showed less degeneration in the Exp group at 15 and 30 days post-operatively. Nerve neoformation forming a connection between the distal and proximal suture sites was observed in the experimental group. This study presented an alternative to nerve repair using an antioxidant compound.

An alternative to never repair using an antioxidant compound: a histological study in rats

The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site...(AU)

Identification of the nuclear factor kappa-beta (NF-kB) in cortical of miceWistar using Technovit 7200 VCR®

Objective: this study aimed to develop a nondecalcified bone sample processing technique enabling immunohistochemical labeling of proteins by kappa-beta nuclear factor (NF-kB) utilizing the Technovit 7200 VCR® in adultmale Wistar rats.Study Method: A 1.8 mm diameter defect was performed 0.5mm from the femur proximal joint by means of around bur. Experimental groups were divided according to fixing solution prior to histologic processing: Group1- ethanol 70%; Group 2-10% buffered formalin; and Group 3- Glycerol diluted in 70% ethanol at a 70/30 ratio+ 10% buffered formalin. The post-surgical periods ranged from 01 to 24 hours. Control groups included a nonsurgical procedure group (NSPG) and surgical procedures where bone exposure was performed (SPBE) without drilling. Prostate carcinoma was the positive control (PC) and samples subjected to incomplete immunohistochemistry protocol were the negative control (NC). Following euthanization, all samples were kept at 4oC for 7days, and were dehydrated in a series of alcohols at -20oC. The polymer embedding procedure was performed atethanol/polymer ratios of 70%-30%, 50%-50%, 30%-70%, 100%, and 100% for 72 hours at -20oC. Polymerization followed the manufacturer’s recommendation. The samples were grounded and polished to 10-15ìm thickness,and were deacrylated. The sections were rehydrated and were submitted to the primary polyclonal antibody anti-NF-kB on a 1:75 dilution for 12 hours at room temperature.Results: Microscopy showed that the Group 2 presented positive reaction to NF-kB, diffuse reactions for NSPGand SPBE, and no reaction for the NC group.Conclusion: The results obtained support the feasibility of the developed immunohistochemistry technique (AU)

Identification of the nuclear factor kappa-beta (NF-kB) in cortical of mice Wistar using Technovit 7200 VCR®.

OBJECTIVE: this study aimed to develop a nondecalcified bone sample processing technique enabling immunohistochemical labeling of proteins by kappa-beta nuclear factor (NF-kB) utilizing the Technovit 7200 VCR® in adult male Wistar rats. STUDY METHOD: A 1.8 mm diameter defect was performed 0.5 mm from the femur proximal joint by means of a round bur. Experimental groups were divided according to fixing solution prior to histologic processing: Group 1--ethanol 70%; Group 2--10% buffered formalin; and Group 3--Glycerol diluted in 70% ethanol at a 70/30 ratio + 10% buffered formalin. The post-surgical periods ranged from 01 to 24 hours. Control groups included a non-surgical procedure group (NSPG) and surgical procedures where bone exposure was performed (SPBE) without drilling. Prostate carcinoma was the positive control (PC) and samples subjected to incomplete immunohistochemistry protocol were the negative control (NC). Following euthanization, all samples were kept at 4°C for 7 days, and were dehydrated in a series of alcohols at -20°C. The polymer embedding procedure was performed at ethanol/polymer ratios of 70%-30%, 50%-50%, 30%-70%, 100%, and 100% for 72 hours at -20°C. Polymerization followed the manufacturer's recommendation. The samples were grounded and polished to 10-15 m thickness, and were deacrylated. The sections were rehydrated and were submitted to the primary polyclonal antibody anti-NF-kB on a 1:75 dilution for 12 hours at room temperature. RESULTS: Microscopy showed that the Group 2 presented positive reaction to NF-kB, diffuse reactions for NSPG and SPBE, and no reaction for the NC group. CONCLUSION: The results obtained support the feasibility of the developed immunohistochemistry technique.

Microstructural and ultrastructural assessment of inferior alveolar nerve damage following nerve lateralization and implant placement: an experimental study in rabbits.

PURPOSE: The present study assessed damage to the inferior alveolar nerve (IAN) following nerve lateralization and implant placement surgery through optical and transmission electron microscopy (TEM). MATERIALS AND METHODS: IAN lateralization was performed in 16 adult female rabbits (Oryctolagus cuniculus). During the nerve lateralization procedure, one implant was placed through the mandibular canal, and the IAN was replaced in direct contact with the implant. The implant was placed in the right mandible, and the left side was used as a control (no surgical procedure). After 8 weeks, the animals were sacrificed and samples were prepared for optical and TEM analysis of IAN structural damage. Histomorphometric analysis was performed to determine the number and cross-sectional dimensions of nerve fascicles and myelin sheath thickness between experimental and control groups. The different parameters were compared by one-way analysis of variance at the 95% significance level. RESULTS: Alterations in the perineural and endoneural regions of the IAN, with higher degrees of vascularization, were observed in the experimental group. TEM showed that the majority of the myelinated nerve fibers were not affected in the experimental samples. No significant variation in the number of fascicles was observed, significantly larger fascicle height and width were observed in the control group, and significantly thicker myelin sheaths were observed in the experimental samples. CONCLUSION: IAN lateralization resulted in substantial degrees of tissue disorganization at the microstructural level because of the presence of edema. However, at the ultrastructural level, small amounts of fiber degeneration were observed.

Bone regeneration in rabbit sinus lifting associated with bovine BMP.

Autogenous bone is considered the optimal grafting material for sinus lifting, although its harvesting causes great patient discomfort. Various approaches have been taken in order to obtain sinus lifting with preexisting tissue. However, because of the unsuitability of such tissue, additional materials have been required. Alternatively, biomaterials from humans or other animals are used. In this study, the efficacy of using morphogenetic bovine bone protein (BMPb) to augment the maxillary sinus floor was examined. Four grafting materials were employed: lyophilized bovine bone powder, absorbable collagen flakes, natural hydroxylapatite, and synthetic hydroxylapatite. Two groups of rabbits were studied. In one group, graft material only was used. In the other, graft material was combined with 0.5 mg BMPb. During 8 weeks of observation, polyfluorochrome tracers were injected in subcutaneous tissue to evaluate new bone- deposition periods. Following sacrifice, the samples were examined under fluorescent and light microscopes. Results indicated 33.34% more newly formed bone in BMPb animals than in controls. Graft-material resorption increased, but natural HA showed no significant alterations. The results show that the use of BMPb, although providing osteoinduction, might not promote sufficient bone formation. Nonetheless, this material could provide an alternative to autogenous grafts, thereby avoiding patient discomfort.

The effects of bovine BMP associated to HA in maxillary sinus lifting in rabbits.

This study examines the efficacy of using bone morphogenetic protein of bovine origin associated with other biomaterials in maxillary sinus floor augmentation procedures in rabbits (Oryctolagus cuniculus). Various approaches have been attempted to obtain sinus lifting with pre-existing tissue, but all of them have been considered inadequate, because such tissue offers very low bio-quality, requiring additional materials to stimulate bone neo-formation. For this purpose, autogenous bone is considered to be the best grafting material, but harvesting it results in great discomfort for the patient. Biomaterials from human beings or other animals are used as a substitute. In this study, four different grafting materials were used: lyophilized bovine bone powder, absorbable collagen flakes, natural hydroxyapatite (nHA) and synthetic hydroxyapatite (sHA), in nine animals divided into two groups: (A) control group (left sinus)--using just graft material, and (B) BMP group (right sinus)--using graft material with 0.5 mg bovine bone morphogenetic protein (BMPb). The observation periods were of 8 and 12 weeks duration and sequential bone neo-formation polyfluorochrome tracers (alizarin complex, calcein, and tetracycline) were subcutaneously injected, to evaluate the periods of new bone deposition. After the animals were sacrificed, the material was obtained and examined under a fluorescent microscope and also activated by UV light and the conclusion reached that the newly formed bone increase was of 33.34% when compared to the control group at 8 weeks At 12 weeks, the bone deposition in the "BMP" group was not significant while in the "control" group there was continuous growth. This difference showed that the BMP stimulated bone formation during the early periods of healing (8 weeks), although it altered the normal cycle of bone deposition over the longer period (12 weeks). The graft material showed increasing reabsorption, but the natural HA did not show significant alterations. The results of this new animal model indicated that the BMPb used, although facilitating osteoinduction, might not be sufficient to promote qualitative and quantitative bone neo-formation, which could guarantee better prognoses. The BMPb material studied may possibly become an alternative to autogenous grafts causing less discomfort for the patient.