Browsing by Subject "Alveolar bone"

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    Alveolar bone of BBMl rats: a morphometric and histochemical study
    (Murcia : F. Hernández, 1989) Johnson, R. B.; Carlson, E. C.
    The present study reported histochemical changes in alveolar bone glycosaminoglycans (GAG) (using Safranin 0 ) and in interdental bone height in three groups of BB/W rats: diabetic, diabetes prone, and diabetes resistant. Safranin O staining intensity suggested that total GAG levels were highest in diabetic bone (p<0.05 compared to diabetes resistant, p<0.005 compared to diabetes prone) but not significantly different between diabetes prone and resistant groups. Following chondroitinase AC and ABC digestion, staining reactions suggested that the highest levels of dermatan sulfate were in the diabetes resistant group (p<0.001 compared to diabetic, p<0.001 compared to diabetes prone) and the highest levels of chondroitin sulfates were in the diabetes prone group (p<0.001). Coincidently the mean height of diabetes prone interdental septum was significantly less than that of diabetes resistant or diabetic groups (p<0.05). The study suggested that 1) diabetes and «prediabetes» produce significant changes in levels of chondroitin 4, 6, and dermatan sulfates within alveolar bone, 2) in «prediabetic» animals, interdental bone loss occurs prior to the onset of clinical symptoms and in the absence of local irritating factors, the bone height appears to return to normal levels, and 3) there may be a correlation between alveolar bone height and relative levels of dermatan sulfate.
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    Histological examination on osteoblastic activities in the alveolar bone of transgenic mice with induced ablation of osteocytes
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2013) Li, Minqi; Hasegawa, Tomoka; Hogo, Hiromi; Tatsumi, Sawako; Liu, Zhusheng; Guo, Ying; Sasaki, Muneteru; Tabata, Chihiro; Yamamoto, Tsuneyuki; Ikeda, Kyoji; Amizuka, Norio
    The purpose of this study was to examine histological alterations on osteoblasts from the alveolar bone of transgenic mice with targeted ablation of osteoctyes. Eighteen weeks-old transgenic mice based on the diphtheria toxin (DT) receptor-mediated cell knockout (TRECK) system were used in these experiments. Mice were injected intraperitoneally with 50 µg/kg of DT in PBS, or only PBS as control. Two weeks after injections, mice were subjected to transcardiac perfusion with 4% paraformaldehyde in 0.1M phosphate buffer (pH 7.4), and the available alveolar bone was removed for histochemical analyses. Approximately 75% of osteocytes from alveolar bones became apoptotic after DT administration, and most osteocytic lacunae became empty. Osteoblastic numbers and alkaline phosphatase (ALP) activity were markedly reduced at the endosteum of alveolar bone after DT administration compared with the control. Osteoblastic ALP activity in the periodontal ligament region, on the other hand, hardly showed any differences between the two groups even though numbers were reduced in the experiment group. Silver impregnation showed a difference in the distribution of bone canaliculi between the portions near the endosteum and the periodontal ligament: the former appeared regularly arranged in contrast to the latter’s irregular distribution. Under transmission electron microscopy (TEM), the osteoblasts in the periodontal ligament showed direct contact with the Sharpey’s fibers. Thus, osteoblastic activity was affected by osteocyte ablation in general, but osteoblasts in contact with the periodontal ligament were less affected than endosteal osteoblasts.
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    Influence of the number of microthreads on marginal bone loss: a five-year retrospective clinical study in humans
    (MDPI, 2023-03-20) Jornet García, Alfonso Felipe; Sánchez Pérez, Arturo Joaquín; Planes Nicolás, Pablo; Montoya Carralero, José María; Moya Villaescusa, María José; Dermatología, Estomatología, Radiología y Medicina Física
    The purpose of the present study was to evaluate the clinical and radiographic outcomes of the number of microthreads on marginal bone over 5 years. Thirty-two implants were placed in 32 patients with partially edentulous maxillae or mandibles. Two implants with the same characteristics were placed: the first one had a 1 mm crest module and 3 microthreads (Q); and the second one had a 3 mm crest module and nine microthreads (S). The prosthesis was inserted 3 months after implant placement. Clinical and radiographic examinations were performed at the one-week, one-month, and three-month follow-up visits and then every six months until a five-year follow-up period was completed. After 5 years of follow-up, five patients withdrew from the study. Complete data were available for 27 implants, with a 100% implant survival rate. No cases of peri-implantitis were diagnosed. The average bone loss was 0.65 mm (C.I. 0.21–1.09) for Q implants and 0.86 mm (C.I. 0.39–1.33) for S implants, with no statistically significant difference. The bone level does not vary between implants with three and nine microthreads or with a 1 mm and 3 mm crest module. No differences in clinical parameters were found.
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    Proteoglycans of alveolar bone of diabetic and non-diabetic mice, a histochemical study
    (Murcia : F. Hernández, 1987) Johnson, R. B.
    The effect of diabetes mellitus on the interdental alveolar bone has been long debated. The present study reported the distribution of glycosaminoglycans (GAG) in normal and diabetic alveolar bone using histochemical techniques. Animals were rendered diabetic and killed at 2,4,6 and 9 weeks after injections. Tissues were stained with Alcian blue 8GX dye (pH 2.5) to demonstrate GAG and the intensity of the staining reactions compared with age-matched controls. During the experiment, weights of control animals did not change significantly; weights of diabetic animals were significantly less than initial weights from O- 6 weeks (p<0.001), but became nearly equal by 9 weeks. Staining intensity of diabetic bone demonstrated initial decrease (0-4 weeks) followed by a marked increase (4-9 weeks) suggesting an early decline in bone GAG levels followed by increased bone GAG levels as compared to age-matched control and initial levels. Bone GAG levels were significantly different between diabetics and agematched controls at 2 (p<0.005) 4 (p<0.001), 6 (p<0.001) and 9 (p<0.001) weeks after streptozotocin injections. Digestion with chondroitinase AC, ABC and streptomyces hyaluronidase suggested significant differences between control and diabetic bone matrix in the levels of chondroitin 4 and 6 sulfates (p<0.05) and hyaluronic acid (p<0.001) but not dermatan sulfate. In control and diabetic bone, chondroitin sulfates were located within the bone matrix, dermatan sulfate within bone matrix and Sharpey fiber bundles. Thus, bone GAG changes in diabetes mellitus occur predominately within bone matrix and are variable depending on the length of the disease.