Periodontal tissue reaction to customized nano-hydroxyapatite block scaffold in one-wall intrabony defect: a histologic study in dogs

PURPOSE: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. METHODS: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral 4x4x5 mm (buccolingual widthxmesiodistal widthxdepth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. RESULTS: Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. CONCLUSIONS: In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

Periodontal tissue reaction to customized nano-hydroxyapatite block scaffold in one-wall intrabony defect: a histologic study in dogs

PURPOSE: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. METHODS: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral 4x4x5 mm (buccolingual widthxmesiodistal widthxdepth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. RESULTS: Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. CONCLUSIONS: In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

Periodontal regenerative effect of a bovine hydroxyapatite/collagen block in one-wall intrabony defects in dogs: a histometric analysis

PURPOSE: The aim of this study was to elucidate the effect of a bovine hydroxyapatite/collagen (BHC) block in one-wall intrabony periodontal defects in dogs. METHODS: A one-wall intrabony periodontal defect (4 mm wide and 5 mm deep) was prepared bilaterally at the mesial side of the mandibular fourth premolar in five beagle dogs. After thorough root planing, block-type BHC (4x5x5 mm) was placed on one side. The contralateral defect area did not receive any material as a sham-surgery control. Histological analysis of the sites was performed after an 8-week healing period. RESULTS: Two of five samples in the experimental group healed well without dissipation of the graft materials, and histological analysis revealed excellent regeneration of the periodontal tissues. However, most of the grafted materials had been displaced in the other three samples, leaving only a small portion of the graft. The measured parameters exhibited large standard deviations, and the mean values did not differ significantly between the experimental and sham-surgery control sides. CONCLUSIONS: The application of BHC alone-without a barrier membrane-to wide, one-wall intrabony periodontal defects yielded inconsistent results regarding both periodontal regeneration and substantivity of the graft materials. Thus, the use of a barrier membrane for noncontained-type defects is recommended to improve the stability of the grafted material, and to condense it.

The effects of bioactive glass on the periodontal healing of 1-wall intrabony defects in dogs / 대한치주과학회지

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease, and numerous kinds of materials and techniques have been developed to achieve this goal. Bone grafts include autografts, allografts, xenografts and synthetic grafts. Among the synthetic grafts, bioactive glass has been used in dentistry for more than ten years and Fetner reported improved new bone formation and more amount of new attachment after grafting PerioGlas , a kind of bioactive glass, in 2-wall defects of monkeys in 1994. It is well known that 1-wall defects have less osteogenic potential and more epithelial migration, so we need to study the effect of bioactive glass in 1-wall defects in dogs. The present study evaluates the effect of bioactive glass on the epithelial migration, alveolar bone regeneration, cementum formation and gingival connective tissue attachment in intrabony defects of dogs. Four millimeter deep and four millimeter wide 1-wall defects were surgically created in the mesial aspects of premolars. The test group received bioactive glass with a flap procedure and the control underwent flap procedure only. Histologic analysis after 8 weeks of healing revealed the following results: 1. The height of gingival margin was 1.30+/-0.73mm above CEJ in the control and 1.40+/-0.78mm in the test group. There was no statistically significant difference between the two groups. 2. The length of epithelial growth(the distance from CEJ to the apical end of JE) was 1.74+/-0.47mm in the control and 1.12+/-0.36mm in the test group. There was a statistically significant difference between the two groups(P<0.01) 3. The length of new cementum was 2.06+/-0.73mm in the control and 2.62+/-0.37mm in the test group. There was no statistically significant difference between the two groups. 4. The length of new bone was 1.83+/-0.74mm in the control and 2.39+/-0.59mm in the test group. There was no statistically significant difference between the two groups. These results suggest that the use of bioactive glass in 1-wall intrabony defects has significant effect on the prevention of junctional epithelium migration, but doesn't have any significant effect on new bone and new cementum formation.