Homeopathic treatment for bone regeneration: experimental study

Aim and method: The objective of this research was to study the effect of homeopathic treatment with Plumbum metallicum (Plumbum met.) on mandibular bone repair in rats.Materials and methods: We analyzed the mandibles of 60 male rats, approximately 3-month-old, randomly divided into three groups of 20 animals each: control, treated with calcitonin, and treated with a homeopathic medicine. A circumscribed bone defect measuring 4 mm in diameter was made in the mandible and covered with a pollytetrafluorethylene (PTFE) barrier. The group treated with calcitonin received 2 IU/kg intramuscularly three times a week; the group treated with Plumbum met. 30c received three drops in water every day. The animals were sacrificed after 7,14,21 and 28 days. The mandibles were removed and submitted to histologic and histomorphometric analyses.Results: Data were analyzed statistically by two-way ANOVA and by the Tukey test. The interaction effect (ANOVA, F df(6; 48) = 4.64; p = 0.001 < 0.05) indicated that the relationship between treatments was not the same at each time of sacrifice. Although statistical analysis of the histomorphometric data showed a similar results for the treated and control groups. But histological analysis showed complete filling of the surgical defect throughout its extent was only for the group treated with Plumbum met.Conclusion: The study demonstrated that for repair of surgical defects in rat mandibles Plumbum met. 30c and control did not differ significantly in histomorphometric terms. Homeopathy (2009) 98, 92-96.

Composites PVDF-TrFE/BT used as bioactive membranes for enhancing bone regeneration

In this paper a piezoelectric composite membranes were developed for charge generator to promoter bone regeneration on defects sites. Is known that the osteogenesis process is induced by interactions between biological mechanisms and electrical phenomena. The membranes were prepared by mixing Barium Titanate (BT) powders and PVDF-TrFE (PVDF:TrFE = 60:40 mol%) on dimethylformamide medium. This precursor solution was dried and crystallized at 100degreesC for 12 hours. Composites membranes were obtained by following methods: solvent casting (SC), spincoating (SP), solvent extraction by water addition (WS) and hot pressing (HP).The microstructural analysis performed by SEM showed connectivity type 3-0 and 3-1 with high homogeneity for samples of ceramic volume fraction major than 0.50. Powder agglomerates within the polymer matrix was evidenced were observed for composites with the BT volume fraction major than 40%. The composite of ceramic fraction of 0.55 presented the best values of remanent polarization (similar to33 muC/cm(2)), but the flexibility of these composites with the larger ceramic fraction was significantly affected.For in vivo evaluation PVDF-TrFE/BT 90/10 membranes with 3cm larger were longitudinally implanted under tibiae of male rabbit. After 21 days the animals were sacrificed. By histological analyses were observed neo formed bone with a high mitotic activity. In the interface bone-membrane was evidenced a pronounced callus formation. These results encourage further applications of these membranes in bone-repair process.

Fibrin adhesive implant in wound healing repair of dental sockets with topical application of epsilon aminocaproic acid: Histological analysis

The aim of the study was to evaluate wound healing repair of dental sockets after topical application of 5% epsilon-aminocaproic acid (EACA) and the use of fibrin adhesive implant in rats under anticoagulant therapy with warfarin. Sixty Albinus wistar rats were used, divided into three groups of 20. In Group I, the animals were given 0.1 mL/100 mg of 0.9% saline solution per day, beginning 6 days before dental extraction and continuing throughout the experimental period. In Group II, the animals received 0.03 mL of sodium warfarin daily, beginning 6 days before the surgery and continuing until the day of sacrifice; after tooth extractions, the sockets were filled with fibrin adhesive material. In Group III the animals were treated as in Group II, and after extractions, the sockets were irrigated with 5 mL of 5% EACA and filled with the same fibrin adhesive material. All groups presented biological phases of wound healing repair, the differences being evident only in the chronology. The results obtained in Group III were very similar to those of Group I in the last period of wound repair, whereas Group II presented a late chronology compared to the other groups. © 2005 Wiley Periodicals, Inc.

Effect of calcitonin on bone regeneration in male rats: a histomorphometric analysis

The aim of this study was to evaluate the effectiveness of calcitonin in promoting bone growth in surgical bone defects in rat mandibles. Fifty male rats were divided into two groups: bone defect (control) and bone defect with calcitonin (experimental). A circular bone defect 4 mm in diameter was made in the mandibular bone of the rats in the angle region, and covered with a polytetrafluoroethylene barrier. The experimental group received 2 IU/kg of synthetic salmon calcitonin intramuscularly three times a week, with treatment starting immediately after surgery. The animals were killed 3, 7, 14, 21 and 28 days after the surgical procedure. The bone defects were examined histologically and by histomorphometric analysis. The Student t-test was applied to the histomorphometric data, with the level of significance set at 5%. The animals of the experimental group showed a lower level of bone formation at almost all time points than the control group, but no difference between groups was observed 28 days after surgery. The volume of newly formed bone matrix was significantly greater in the control than the experimental group at 7, 14 and 21 days, as determined by both morphologic and histomorphometric analysis. Bone repair in the calcitonin-treated animals was delayed in comparison to controls, indicating the need for further studies on male rats.

Histologic Evaluation of the Osteoinductive Property of Autogenous Demineralized Dentin Matrix on Surgical Bone Defects in Rabbit Skulls Using Human Amniotic Membrane for Guided Bone Regeneration

The aim of this investigation was to evaluate the osteoinductive property of autogenous demineralized dentin matrix (ADDM) on experimental surgical bone defects in the parietal bone of rabbits using the guided bone regeneration (GBR) technique incorporating human amniotic membrane (HAM). Thirty-six rabbits were divided into 2 groups, HAM and ADDM+HAM. It was possible to conclude that HAM did not interfere with bone repair and was resorbed. Slices of ADDM induced direct bone formation and were incorporated by the newly formed bone tissue and remodeled. The bone defects healed faster in the ADDM+HAM group than in the group with HAM only.

Influence of simvastatin on bone regeneration of tibial defects and blood cholesterol level in rats

The purpose of this study was to evaluate the effects of simvastatin, by oral or subcutaneous administration, on tibial defects regeneration and blood cholesterol level in rats. A surgical defect was made on the right tibia of 40 male animals assigned to 4 groups (n=10), based on two routes of administration and on the use or not of simvastatin: subcutaneous injection of simvastatin (7 mg/kg) (group AT) or only the vehicle of drug suspension (group AC), above the defect area, for 5 days; and 20 mg/kg of simvastatin macerated on water (group BT) or only water (group BC), orally, daily, during the whole observation period. The animals were sacrificed after 15 or 30 days, when blood samples were analyzed to check plasma cholesterol levels. Tibiae were removed and, after decalcification and routine laboratorial processing, histological and histomorphometrical analyses were carried out. ANOVA was used for statistical analysis at 5% signficance level. The histological and histomorphometrical analyses showed significant differences only between the experimental periods (p<0.05). Animals sacrificed after 30 days showed better bone repair (p<0.05). There was no statistically significant difference (p>0.05) for blood cholesterol levels between the groups. In conclusion, simvastatin administration either orally or subcutaneously did not improve bone repair of experimental tibial defects and did not alter blood cholesterol levels in rats.

Bone regeneration in cranioplasty and clinical complications in rabbits with alloxan-induced diabetes

This research evaluated the bone repair process in surgical defects created on the parietal bones of diabetic rabbits using the guided bone regeneration technique to observe the effects of alloxan in the induction of diabetes mellitus. Twenty-four adult rabbits were divided into three study groups: control (C), diabetic (D) and diabetic associated to polytetrafluoroethylene (PTFE) membrane (D-PTFE). For diabetes induction the animals received one dose of monohydrated alloxan (90 mg/kg) by intravenous administration in the auricular or femoral vein. In group D-PTFE the membrane covered both the floor and the surface of the bone defect. In groups D and C, the bone defect was filled up with blood clot. The specimens were fixed in 10% formol and prepared for histomorphometric analysis. The results showed that the 90 mg/kg dose of monohydrate alloxan was sufficient to promote diabetes mellitus when administered in the auricular vein. Bone regeneration was slower in the diabetic group when compared with the control and diabetic-PTFE groups, but there was no significant statistical difference between the two experimental groups (D and D-PTFE). The oral and general clinical complications among the diabetics were weight loss, polyuria, polyphagia and severe chronic gingivitis.

Evaluation of the bone healing process utilizing platelet-rich plasma activated by thrombin and calcium chloride: A histologic study in rabbit calvaria

To evaluate the bone healing of defects filled with particulate bone graft in combination with platelet-rich plasma (PRP), added with a mixture of calcium chloride and thrombin or just calcium chloride. Two 5-mm bone defects were created in the calvaria of 24 rabbits. Each defect was filled with particulate bone graft and PRP. In one defect the PRP was activated by a mixture of calcium chloride and thrombin; in the other, PRP was activated by calcium chloride only. The animals were euthanized 1, 2, 4, and 8 weeks after the surgeries, and the calvaria was submitted to histologic processing for histomorphometric analysis. The qualitative analysis has shown that both defects presented the same histologic characteristics so that a better organized, more mature, and well-vascularized bone tissue was noticed in the eighth week. A good bone repair was achieved using either the mixture of calcium chloride and thrombin or the calcium chloride alone as a restarting agent of the coagulation process.

Bone Morphogenetic Proteins: Structure, biological function and therapeutic applications

Bone Morphogenetic Proteins (BMPs) are multifunctional secreted cytokines, which belong to the TGF-beta superfamily. These glycoproteins act as a disulfide-linked homo- or heterodimers, being potent regulators of bone and cartilage formation and repair, cell proliferation during embryonic development and bone homeostasis in the adult. BMPs are promising molecules for tissue engineering and bone therapy. The present review discusses this family of proteins, their structure and biological function, their therapeutic applications and drawbacks, their effects on mesenchymal stem cells differentiation, and the cell signaling pathways involved in this process. (C) 2014 Published by Elsevier Inc.

Two-and tridimensional analysis of periapical repair after endodontic surgery

Objective The aim of this study was to evaluate repair after endodontic surgery using two- and tridimensional imaging methods. Materials and methods Periapical radiographs and cone beam computed tomography (CBCT) were performed before the surgeries and after 48 h (baseline), 4 months, and 8 months. The area (square millimeters) of periapical lesions in CBCT and in radiographs was compared regarding the percentage of repair. In the CBCT, multiple areas were converted to volume. Repeated-measures analyses and paired t tests (α=0.05) were used to compare the methods. Correlation coefficients were calculated between the periods of evaluation within the CBCT volumetric analysis. Bland-Altman plots were used to compare the methods, based on the 95 % limits of agreement for the difference of the means. Results Baseline showed a larger lesion volume (192.54 mm3 ) than 4-month (79.79 mm3 ) and 8-month (47.51 mm3 ) periods. No differences were found in the percentage of repair in the first 4 months and after 8 months. The volumetric analysis showed a higher percentage of repair when the first and last 4 months were compared. No differences were found in the percentage of repair by area in the CBCTs. Repair of 73 % was obtained after 8 months. Similar results were observed by the Bland-Altman agreement analyses. Conclusions The percentage of repair varied after 8 months, when lower values were obtained by volumetric evaluation. Clinical relevance Considering the outcome at follow-up periods over 4 months, tridimensional evaluation by CBCT is more capable of determining the absence of periapical bone repair than conventional two-dimensional radiographs. Therefore, the use of CBCT would be suggested only for more complex cases with slower evolution of repair or for the association of factors that make prognosis difficult after surgery.

Periapical Repair Following Endodontic Surgery: Two- andThree-Dimensional Imaging Evaluation Methods

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Use of a new fibrin sealant and laser irradiation in the repair of skull defects in rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Homogenous demineralized dentin matrix and platelet-rich plasma for bone tissue engineering in cranioplasty of diabetic rabbits: biochemical, radiographic, and histological analysis

This study evaluated the effects of homogenous demineralized dentin matrix (HDDM) slices and platelet-rich plasma (PRP) in surgical defects created in the parietal bones of alloxan-induced diabetic rabbits, treated with a guided bone regeneration technique. Biochemical, radiographic, and histological analyses were performed. Sixty adult New Zealand rabbits were divided into five groups of 12: normoglycaemic (control, C), diabetic (D), diabetic with a PTFE membrane (DM), diabetic with a PTFE membrane and HDDM slices (DM-HDDM), and diabetic with PTFE membrane and PRP (DM-PRP). The quantity and quality of bone mass was greatest in the DM-HDDM group (respective radiographic and histological analyses: at 15 days, 71.70±16.50 and 50.80±1.52; 30 days, 62.73±16.51 and 54.20±1.23; 60 days, 63.03±11.04 and 59.91±3.32; 90 days, 103.60±24.86 and 78.99±1.34), followed by the DM-PRP group (respective radiographic and histological analyses: at 15 days 23.00±2.74 and 20.66±7.45; 30 days 31.92±6.06 and 25.31±5.59; 60 days 25.29±16.30 and 46.73±2.07; 90 days 38.10±14.04 and 53.38±9.20). PRP greatly enhanced vascularization during the bone repair process. Abnormal calcium metabolism was statistically significant in the DM-PRP group (P<0.001) for all four time intervals studied, especially when compared to the DM-HDDM group. Alkaline phosphatase activity was significantly higher in the DM-HDDM group (P<0.001) in comparison to the C, D, and DM-PRP groups, confirming the findings of intense osteoblastic activity and increased bone mineralization. Thus, HDDM promoted superior bone architectural microstructure in bone defects in diabetic rabbits due to its effective osteoinductive and osteoconductive activity, whereas PRP stimulated angiogenesis and red bone marrow formation.

Bone substitutes for peri-implant defects of postextraction implants

Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immediately after tooth extraction, this study aimed to present a literature review about biomaterials surrounding immediate dental implants. The search included 56 articles published from 1969 to 2012. The results were based on data analysis and discussion. It was observed that implant fixation immediately after extraction is a reliable alternative to reduce the treatment length of prosthetic restoration. In general, the biomaterial should be used to increase bone/implant contact and enhance osseointegration.

Bovine Bone Matrix Action Associated With Morphogenetic Protein in Bone Defects in Rats Submitted to Alcoholism

Extended excessive alcohol use causes changes in bone tissue, thus affecting osteogenesis. The objective of this study was to evaluate if demineralized bone matrix (Gen-ox (R)) associated with bone morphogenetic protein (Gen-pro (R)) changes bone neoformation in rats submitted to experimental alcoholism. Forty male rats (Rattus norvegicus) were separated into 2 groups of 20 animals each: Group E1, which received ethyl alcohol at 25% and had the surgical cavity filled in only with blood clot; and Group E2. which received ethyl alcohol at 25% and had the surgical cavity filled in with demineralized bovine cortical bone associated with bone morphogenetic protein. The animals were submitted to a three-week period of gradual adaptation to alcohol, and then continued receiving alcohol at 25% for 90 days, when the surgical cavity was made. After the surgery, the animals continued consuming alcohol until reaching the sacrifice periods of 10, 20, 40, and 60 days, when the tibias were removed for histological processing. Results showed that surgical cavity repair and bone marrow reorganization occurred faster in Group E1 than in Group E2. At the end of the experiment, it was observed that animals in Group E2 had thick bony trabeculae surrounding the implanted material particles and a small area of connective tissue in the surface region. In conclusion, the implanted material did not accelerate bone neoformation, rather it served as a structure for osteogenesis.