• Imaging Science in Dentistry
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• v.44 no.2
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• pp.143-148
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• 2014

Purpose: This study evaluated the efficacy of alveolar ridge preservation methods with and without primary wound closure and the relationship between histometric and micro-computed tomographic (CT) data. Materials and Methods: Porcine hydroxyapatite with polytetrafluoroethylene membrane was implanted into a canine extraction socket. The density of the total mineralized tissue, remaining hydroxyapatite, and new bone was analyzed by histometry and micro-CT. The statistical association between these methods was evaluated. Results: Histometry and micro-CT showed that the group which underwent alveolar preservation without primary wound closure had significantly higher new bone density than the group with primary wound closure (P<0.05). However, there was no significant association between the data from histometry and micro-CT analysis. Conclusion: These results suggest that alveolar ridge preservation without primary wound closure enhanced new bone formation more effectively than that with primary wound closure. Further investigation is needed with respect to the comparison of histometry and micro-CT analysis.

• Applied Microscopy
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• v.52
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• pp.13.1-13.6
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• 2022

Microscopic structure of skin in two amphibious mudskipper fish; Boleophthalmus dussumieri Valenciennes, 1837 (B. dussumeri) and Periophthalmus waltoni Koumans, 1941 (P. waltoni) were investigated in relation to their lifestyle. The general structure of skin is the same among the two species. Epidermis in B. dussumeri was thicker significantly than P. waltoni. The dermal bulges were only well developed in the skin of B. dussumeri. Mucous cells were absent in the epidermis of P. waltoni but present in B. dussumeri. Both B. dussumeri and P. waltoni have well-developed swollen middle cells as a shared epidermal feature. The thickness of the middle cell layer of the epidermis in B. dussumeri was significantly greater than in P. waltoni. Capillaries in the dorsal and ventral parts of the body are more closely distributed to the epidermal surface in P. waltoni than in B. dussumeri. The diffusion distance in the dorsal epidermis of P. waltoni was less than that in the ventral epidermis of B. dussumeri. A comparative examination of the skin of mudskipper species suggests that, due to the more terrestrial lifestyle adopted by P. waltoni, the skin contributes more to respiration.

• Journal of Periodontal and Implant Science
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• v.47 no.3
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• pp.143-153
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• 2017

Purpose: The aim of the present exploratory study was to evaluate extraction socket healing at sites with a history of periodontal and endodontic pathology. Methods: The mandibular 4th premolar teeth in 5 adult beagle dogs served as experimental units. Periodontal and endodontic lesions were induced in 1 premolar site in each animal using wire ligatures and pulpal exposure over 3 months (diseased sites). The contralateral premolar sites served as healthy controls. The mandibular 4th premolar teeth were then extracted with minimal trauma, followed by careful wound debridement. The animals were sacrificed at days 1, 7, 30, 60, and 90 post-extraction for analysis, and the healing patterns at the healthy and diseased extraction sites were compared using radiography, scanning electron microscopy, histology, and histometry. Results: During the first 7 days of healing, a significant presence of inflammatory granulation tissue was noted at the diseased sites (day 1), along with a slightly accelerated rate of fibrin clot resolution on day 7. On day 30, the diseased extraction sites showed a greater percentage of persistent fibrous connective tissue, and an absence of bone marrow formation. In contrast, healthy sites showed initial signs of bone marrow formation on day 30, and subsequently a significantly greater proportion of mature bone marrow formation on both days 60 and 90. Radiographs exhibited sclerotic changes adjoining apical endodontic lesions, with scanning electron microscopy showing collapsed Volkmann canals protruding from these regions in the diseased sites. Furthermore, periodontal ligament fibers exhibited a parallel orientation to the alveolar walls of the diseased sites, in contrast to a perpendicular arrangement in the healthy sites. Conclusions: Within the limitations of this study, it appears that a history of periodontal and endodontic pathology may critically affect bone formation and maturation, leading to delayed and compromised extraction socket healing.