Alendronate disturbs femoral growth due to changes during immunolocalization of transforming growth factor-ß1 and bone morphogenetic protein-2 in epiphyseal plate.

BACKGROUND: The epiphyseal growth plate is an important anatomical segment localized on the ends of a long bone. Despite the abovementioned atractive reasons for alendronate's use, few data on the effect of alendronate during epiphyseal growth exist. AIM: Verify the effect of alendronate on the growth epiphyseal plate, and compare its effect with the size of the femur during the double-staining of the immunolocalization of transforming growth factor-ß1 (TGF-ß1) and bone morphogenetic protein-2 (BMP2) in endochondral ossifing in specimens that have received alendronate. METHODS: Forty newborn rats were randomly divided into two groups: a control group (were given applications of 1 mg/kg physiologic saline) and a group that received Alendronate (a dose of 2.5 mg/kg). These groups were then divided into two subgroups for euthanasia in two and 12 d of life. After euthanasia, the femurs were removed, and the femoral bones were measured linearly between the apex of the greater trochanter until the lower intercondylar midlle face to verify the probable bone growth between 3 and 12 d in control and alednroanto treated rats. Posteriorly, the surgical pieces were also sent to the histopathology laboratory to produce histological slides. The obtained slides were stained with hematoxylin and eosin to measure each of the cartilage zones in endochondral development. and other slides were immunohistochemically tested for anti- TGF-ß1 and BMP-2 antibodies to investigate the immunolocalization of these proteins in the epiphyseal plaque area. RESULTS: On the third day, some diferences between the control group and specimens treated with alendronate were verified. Macroscopiccaly, we found similarities in size between the femoral bones when we compared the control group with the specimens that received alendronate. On the 12th day, the bone size of the mice receiving the drug was significantly smaller than those of the control group. These results coincide with changes in the TGF-ß1 and BMP-2 expression. In the specimens that received alendronate, the TGF-ß1 was expressed in some sites of trabecular bone that was neoformed, peripherally to the bone marrow area. The BMP-2 was also positive in proliferative chondrocytes and hypertrofic chondrocytes. On the 12th day, all layers of chondrocytes exhibited positivity for BMP-2 in the specimens that received alendronate. In the interface between the trabecular bone and cartilage, an area of disorganized bone deposition was evident. Neoformed bone also appeared to be different at 12 d. In the control group, BMP-2 was positive in an intense area of bone trabeculae, whereas the alendronate-treated group showed TGF-ß1 positive trabeculae and a greater bone area. CONCLUSION: Alendronate alters the immunolocalization of TGF-ß1 and BMP-2 simultaneously, a condition that changes the usual histological aspects of the cartilage zone and impairs epiphysis growth and femur growth.

Effects of Active Oxygen Toothpaste in Supragingival Biofilm Reduction: A Randomized Controlled Clinical Trial.

Gingivitis is still considered a major risk factor for the occurrence and progression of periodontal disease. The aim of the present study was to compare the long-term (1, 12, and 18 weeks) antiplaque and antigingivitis efficacies of two commercially available toothpastes, Colgate Total® (CT) and BlueM® (BM), against attached supragingival dental plaque and gingival inflammation in an experimental gingivitis model. A parallel double-blinded randomized clinical trial including 39 dental students who refrained from all plaque control methods (manual or chemical) for 7 days was conducted. After the establishment of clinical gingivitis, participants were randomized into two experimental groups (CT and BM). Plaque index (PI) and gingival index (GI) were then calculated according to Turesky's modified Quigley and Hein index. Participants were assessed in four time periods (preclinical trial phase (W -1), gingivitis phase (W0), one week (W1), twelve weeks (W12), and eighteen weeks (W18)). Participants' stimulated saliva was collected and cultured (either aerobically or anaerobically, 37°C, 48 hours) in each time period (W -1, W0, W1, W12, and W18) for the count of viable colonies. Obtained data were analyzed using 2-way ANOVA and Tukey's test (α = 0.05). No significant differences were found (p > 0.05) between experimental groups at W -1. Significant differences between groups were observed at W0 (p < 0.05) for the parameter time period, but not for the interaction between parameters (time period ∗ toothpastes). Lower bacterial counts were observed in both groups after one week of toothbrushing; however, no significant differences were found between investigated dentifrices. Intra- and intergroup comparisons revealed that significant differences were not found (p > 0.05) between dentifrices at W1, W12, and W18 for both GI and PI. The present study demonstrated that toothpastes containing active oxygen and lactoferrin (BM) have comparable antiplaque and antigingivitis efficacies with triclosan-containing toothpastes (CT).

A modified free gingival graft technique for gaining vertical and horizontal soft tissue augmentation.

The aim of this case report was to describe a modified free gingival graft technique for gaining vertical and horizontal soft-tissue growth in the posterior region of the mandible before installation of dental implants. Patient A.A., a 38-year-old female, received a modified free gingival graft in the posterior region of the mandible. After 90 days, an increase, both horizontally and vertically, of the gingival tissue was observed, and the patient was satisfied with the result. The dental implant was installed, and a 3-mm of the vertical gain of keratinized gingiva was observed. Further research is needed to evaluate the effectiveness of this technique before prosthetic dental implantation.

Would Be Prophylactic Administrations of Low Concentration of Alendronate an Alternative for Improving the Craniofacial Bone Repair? A Preliminary Study Focused in the Period of Cellular Differentiation and Tissue Organization.

BACKGROUND: Alendronate (ALN) is a nitrogen-bisphosphonate that may induce an anabolic effect on craniofacial bone repair when administrated in low doses. Based on this premise, this study analyzed the influence of prophylactic low doses of ALN on bone healing in defects created in rabbit mandible. METHODS: A 5 × 2-mm diameter deep defect was created in the calvaria of 28 rabbits. Fourteen of these rabbits received previously 50 µg/kg of 1% sodium ALN for 4 weeks, while the other rabbits received only 0.9% physiological saline solution (control). Animals were euthanized at 15 and 60 days postsurgery (n = 7), and the data were analyzed using histomorphometry and immunohistochemistry using the anti-CD34, bone morphogenetic protein -2 (BMP-2), and transforming growth factor (TGF)-ß1 antibodies. RESULTS: On the 15th day postsurgery, the specimens that received previous treatment with ALN demonstrated large vascular lumen and intense positivity to CD34 either concentrated in endothelium or cells spread among the reparative tissue. These results coincided with intense positivity for BMP-2+ cells and TGF-ß1 that was concentrated in both cells and perivascular area. In contrast, the control group revealed scarce cells that exhibited CD34, BMP-2+, and the TGF-ß1 was restricted for perivascular area on well-formed granulation tissue. These patterns of immunohistochemical result, especially found on the 15th day of analysis, seem to be responsible for the development of larger quantities of bone matrix in the specimens that receive ALN on the 60th day postsurgery. CONCLUSION: These preliminary results showed that the prophylactic administration of low doses of ALN might be an alternative to craniofacial bone craniofacial bone repair because it increases the immunopositivity for TGF-ß1 and consequently improves the CD34+ and BMP-2+ cells on reparative sites.

Comparison of conventional and semilunar coronally positioned flap techniques for root coverage in teeth with cervical abrasion restored with pink resin.

Gingival recession is the most common mucogingival defect, characterized by apical migration of the gingival margin from the cementoenamel junction and root exposure. Several surgical techniques are reported for the treatment of gingival recession. Here we present a comparison of the conventional (coronally advanced flap) and semilunar coronally positioned flap techniques for root coverage in teeth with cervical abrasion restored with pink resin that mimics the color of the gingiva. Although the conventional technique is more predictable, we found that both techniques were effective in achieving satisfactory and esthetic root coverage.

Leukocyte-platelet-rich plasma diminishes bone matrix deposition in rat calvaria treated with autograft due to simultaneous increase in immunohistochemical expression of Indian Hedgehog, transforming growth factor-ß, and parathyroid-1 receptor.

PURPOSE: This study evaluated the immunohistochemical presence of Indian Hedgehog (IHH), transforming growth factor-ß (TGF-ß), and parathyroid-1 receptor (PTH1R) in calvaria bone repair, and compared these results with the histological bone matrix features in defects treated with autograft in the presence or absence of L-PRP. MATERIAL AND METHODS: An artificial bone defect measuring 5 × 1 mm was produced in the calvaria of 28 Wistar rats. Randomly the defects were treated with autograft and autograft mixed with L-PRP. The animals were euthanized at 15 and 40 days post-surgery. Data were analyzed by Student-Newman-Keuls test (p ≤ .05) for immunohistochemical interpretation. RESULTS: The results revealed that the histological characteristic of bone matrix deposited in the defect was different in the defects treated with L-PRP. The group that received only the autograft demonstrated larger haversian bone matrix deposited, whereas the group that received autograft mixed with L-PRP revealed trabecular bone deposition. These results coincided with significantly higher immunopositivity for IHH, TGF-ß1, and PTH1R in the L-PRP group. CONCLUSION: These results suggest that L-PRP altered the biological characteristic of the autograft, increasing the bone cells IHH+ but inducing a trabecular bone associated with intense quantities of TGF-ß and PTH1R.

Platelet-leukocyte-rich plasma (L-PRP) prevents the collagen III degradation and impairs the bone matrix development in artificial defect of rabbit calvaria, associated with suppression of the immunohistochemical expression of MMP-2 and MMP-9

Introduction and Objective: Because L-PRP constitutes an important source of growth factor that is associated with osteogenesis and fibrogenesis, the aim of this study was to evaluate the effect of L-PRP on the presence of collagen III and MMP-2 and MMP-9, while comparing these results by means of a histomorphometric analysis of bone matrix and fibrous deposition on bone repair. Material and methods: Four bone defects of 8 × 2 mm were created on the calvaria of 21 rabbits. The surgical defects were treated with either particulate autograft, particulate autograft mixed with L-PRP, or L-PRP alone. Animals were euthanized at 2, 4, and 6 weeks postoperative. Histomorphometric and immunohistochemical analyses were performed to assess repair time, as well as the expression of collagen III and MMPs. Results: In contrast to the results of the L-PRP-free groups, the histomorphometric results of the L-PRP groups demonstrated intense fibrotic deposition along with hindered bone matrix deposition. These results coincided with the larger occurrence of diffuse collagen III deposition and the scarce presence of MMP- 2 and -9 spread among the fibrous tissue. Conclusion: Thus, the results suggest that L-PRP not only induces an intense fibrosis rich in collagen III, which is not degraded, but also suppresses MMP-2 and -9 expressions, mimicking a similar pathological event as that of a cleft-palate or cranial suture.