One-wall Intrabony Defects In Dogs Research Articles

Preclinical Evaluation of a Poly (Lactic Acid/Caprolactone) Bilayer Membrane and a Carbonate Apatite for Periodontal Regeneration: A Canine One-Wall Intrabony Defect Model.

This preclinical study aimed to evaluate the periodontal tissue regenerative capacities of poly (lactic acid/caprolactone) (PLCL) bilayer membrane in one-wall intrabony defects in dogs. No study has assessed the efficacy of PLCL bilayer membrane for periodontal regeneration therapy despite the fact that PLCL bilayer membrane has proved efficient for bone regeneration. In five beagle dogs, the bilateral mandibular second and fourth premolars were extracted 8 weeks before the experimental surgery. Standardized bone defects (5 mm in height and 6 mm in width) were surgically created on the mesial and distal roots of the bilateral third premolars in the mandible. The test groups were set up as follows: (i) carbonate apatite (CO3Ap) + PLCL, (ii) CO3Ap, (iii) xenograft (DBBM) + collagen membrane (CM), and (iv) DBBM. The control group was left empty. Radiological, histologic and histomorphometric characteristics were compared 8 weeks after surgery. No infectious complications were detected at any of the tested sites. The test groups exhibited a greater height and volume of the newly formed bone than the control group. They also showed a greater height of the newly formed cementum than the control group. However, the results were not statistically significant. The newly formed periodontal ligaments were inserted into newly formed bone and cementum in the test groups. The combined use of PLCL bilayer membrane and CO3Ap demonstrated comparable performance for periodontal tissue regeneration in one-wall intrabony defects compared to conventional therapies.

Octacalcium phosphate collagen composite for periodontal regeneration in a canine one-wall intrabony defect.

This study aimed to evaluate the regenerative capacities of octacalcium phosphate collagen composite (OCP/Col) in one-wall intrabony defects in dogs. The background data discuss the present state of the field: No study has assessed the efficacy of OCP/Col for periodontal regeneration therapy despite the fact that OCP/Col has proved to be efficient for bone regeneration. In six beagle dogs, the mandibular left third premolars were extracted 12 weeks before the experimental surgery. Standardized bone defects (5 mm in height and 4 mm in width) were simulated on the distal surface of the second premolars and mesially on the fourth premolars. The defect was filled with either OCP/Col (experimental group) or left empty (control group). Histological and histomorphometric characteristics were compared 8 weeks after surgery. No infectious or ankylotic complications were detected at any of the tested sites. The experimental group exhibited a significantly greater volume, height, and area of newly formed bone than the control group. The former also showed a greater height of the newly formed cementum than the latter, although the results were not statistically significant. The newly formed periodontal ligaments were inserted into newly formed bone and cementum in the experimental group. OCP/Col demonstrated high efficacy for bone and periodontal tissue regeneration that can be successfully applied for one-wall intrabony defects.

Preclinical evaluation of the effect of periodontal regeneration by carbonate apatite in a canine one-wall intrabony defect model.

This study aimed to histologically compare periodontal regeneration of one-wall intrabony defects treated with open flap debridement, β-tricalcium phosphate (β-TCP), and carbonate apatite (CO3Ap) in dogs. The mandibular third premolars of four beagle dogs were extracted. Twelve weeks after the extraction, a one-wall bone defect of 4mm×5mm (mesio-distal width×depth) was created on the distal side of the mandibular second premolar and mesial side of the fourth premolar. Each defect was randomly allocated to open flap debridement (control group), periodontal regeneration utilizing β-TCP, or CO3Ap. Eight weeks after the surgery, histologic and histometric analyses were performed. No ankylosis, infection, or acute inflammation was observed at any of the experimental sites. Newly formed bone and cementum were observed in all experimental groups. The mineral apposition rate of the alveolar bone crest was higher in the CO3Ap group than in the control and β-TCP groups. The ratio of the new bone area was significantly higher in the CO3Ap group than in the control group (P<0.05). The bone contact percentage of the residual granules was significantly higher in the CO3Ap group than in the β-TCP group (P<0.05). Although this study has limitations, the findings revealed the safety and efficacy of CO3Ap for periodontal regeneration in one-wall intrabony defects in dogs, and CO3Ap has a better ability to integrate with bone than β-TCP.

Effect of a tunnel-structured β-tricalcium phosphate graft material on periodontal regeneration: a pilot study in a canine one-wall intrabony defect model.

Tissue regeneration is affected by the porosity, chemical properties and geometric structure of graft materials. Regeneration of severe periodontal defects, such as one-wall intrabony defects, is difficult because of reduced tissue support, and bone grafts are commonly used in such cases. In the present study, a tunnel-structured β-tricalcium phosphate (tunnel β-TCP) graft material designed to stimulate bone formation was fabricated. The objective of this pilot study was to evaluate the effect of this graft material on periodontal regeneration in one-wall intrabony defects in dogs. Six male beagle dogs were used in this study. First, the mandibular second and third incisors were extracted. Experimental surgery was performed 12 wk after tooth extraction. Bilateral 4 × 8 mm (width × depth) one-wall intrabony defects were created in the mesial side of the mandibular canines. At the experimental sites, the defects were filled with tunnel β-TCP, whereas the control defects were left empty. Twelve weeks after surgery, qualitative and quantitative histological analyses were performed. There were no signs of clinical inflammation 12 wk after surgery. Coronal extension indicative of new bone formation was higher at the experimental sites than at the control sites, although the differences between both the sites in the newly formed cementum and connective tissue attachment were not significant. Newly formed periodontal ligament and cementum-like tissue were evident along the root surface at the experimental sites. The inner surface of the tunnels was partially resorbed and replaced with new bone. New blood vessels were observed inside the lumens of tunnel β-TCP. Tunnel β-TCP serves as a scaffold for new bone formation in one-wall intrabony defects.

Space maintenance using crosslinked collagenated porcine bone grafted without a barrier membrane in one‐wall intrabony defects

The aim of this study was to determine the efficacy of crosslinked collagenated porcine bone (CPB) for the repair of surgically prepared one-wall intrabony defects in dogs. Buccolingually opened, one-wall, box-type periodontal defects (4 × 5 mm) were prepared bilaterally at the mesial side of the mandibular fourth premolars in beagle dogs (N = 5). Block-type CPB (4 × 5 × 5 mm) was placed on either the left or right side for the CPB site; the opposite site served as a sham-surgery control. Micro-computed tomographic and histological analyses were performed on block specimens obtained from the dogs after a 3-month healing period. There was less mean bone regeneration and cementum regeneration at the experimental sites than at the sham-surgery control sites. Most of the porcine bone particles were located under the floor of the defect and were sequestered from pristine bone. These findings show that CPB can be localized within the defect during the wound-healing period by a process of crosslinking; however, the application of CPB alone without a barrier membrane may not be effective in promoting periodontal regeneration in noncontained-type defects.

Effects of EMD in combination with bone swaging and calcium phosphate bone cement on periodontal regeneration in one‐wall intrabony defects in dogs

Although the application of EMD is a widely accepted periodontal-regenerative therapy, its effects on noncontained intrabony defects are unpredictable because of the lack of a space-making property. The combined use of EMD and autogenous bone grafts reportedly stimulates significant periodontal regeneration in intrabony defects. The aim of the present study was to evaluate the effects of EMD in combination with bone swaging (BS) and injectable calcium phosphate bone cement (CPC), which was placed into the spaces between the grafted swaged bone and the proximal host bone, on periodontal healing in one-wall intrabony defects in dogs. One-wall intrabony defects (3 mm wide and 5 mm deep) were surgically created on the mesial and distal sides of the bilateral mandibular premolars in four dogs. The 16 defects were assigned to one of the following treatments: EMD only, BS only, EMD with BS (EMD + BS), or EMD with BS and CPC (EMD + BS + CPC). The animals were killed 8 wk after surgery for histologic evaluation. The height of newly formed bone was significantly greater in the EMD + BS + CPC group (3.73 ± 0.30 mm) than in the BS-only (2.74 ± 0.33 mm; p < 0.05) and EMD + BS (2.88 ± 0.98 mm; p < 0.05) groups. The area of newly formed bone was significantly larger in the EMD + BS + CPC group (5.68 ± 1.66 mm(2)) than in the EMD-only (3.68 ± 0.33 mm(2); p < 0.05), BS-only (3.48 ± 1.26 mm(2); p < 0.05) and EMD + BS (3.38 ± 1.37 mm(2); p < 0.05) groups. The EMD-only (4.63 ± 0.42 mm), EMD + BS (4.67 ± 0.30 mm) and EMD + BS + CPC (4.78 ± 0.54 mm) groups showed significantly greater cementum formation than did the BS-only group (3.93 ± 0.56 mm; p < 0.05). These results indicate that treatment with EMD + BS + CPC promotes favorable periodontal healing in one-wall intrabony defects in dogs.

Maturation of periodontal tissues following implantation of rhGDF‐5/β‐TCP in one‐wall intra‐bony defects in dogs: 24‐week histological observations

Although a previous study reported that recombinant human growth/differentiation factor-5 (rhGDF-5) coated onto a β-tricalciumphosphate (β-TCP) significantly enhanced periodontal regeneration, the long-term stability/maturation of the regenerated tissues has not been demonstrated. The objective of this study was to evaluate periodontal regeneration/maturation following application of rhGDF-5/β-TCP using an established periodontal defect model and a 24-week healing interval. Unilateral, surgically created, 4 × 4 × 5 mm (length × width × height), one-wall, critical-size, intra-bony periodontal defects at the mandibular second and fourth premolar teeth in five young adult Beagle dogs received rhGDF-5/β-TCP. Bilateral sites at the fourth premolar in the other four dogs served as pristine controls receiving mucogingival flap surgery without defect induction. The animals were euthanized at 24 weeks for histological analysis. Unpublished data from the previous 8-week study were used to compare tissue maturation between 8 and 24 weeks. Linear histometric observations of cementum and alveolar regeneration showed no significant differences between the 8- and 24-week observation intervals. However, parameters of periodontal tissue maturation showed significant differences between the observation intervals including increased fraction mineralized tissue and lamellar bone (p < 0.05) and decreased osteocyte counts (p < 0.05) at 24 weeks compared with 8 weeks. Although the count inserting Sharpey's fibre did not significantly change, regenerated cementum remote from the intact periodontal ligament appeared more highly mineralized and thicker at 24 weeks compared with 8 weeks, and compared with the pristine cementum. Minimal β-TCP remained. These 24-week observations suggest that regenerated periodontal tissues in sites receiving rhGDF-5/β-TCP undergo progressive maturation without debilitating aberrant tissue reactions.

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

PurposeThe aim of this study was to elucidate the effect of a bovine hydroxyapatite/collagen (BHC) block in one-wall intrabony periodontal defects in dogs.MethodsA 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 (4×5×5 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.ResultsTwo 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.ConclusionsThe 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.