Sustained Release of Vitamin D3 Enhanced Osseointegration Capacity: An Experimental Sheep Study

This study aimed to investigate the effect of sustained-release vitamin D loaded in poly-lactic acid (PLA) nanoparticles and applied to grafting materials around titanium (ti) dental implants. A total of 48 implants were inserted into the standardized bone defects created in the iliac crest of 6 sheep, divided into 4 different experimental sites (empty control, autografted, xenografted, and autograft + xenografted). Vitamin D3, which was encapsulated by PLA nanoparticles, was prepared and applied in half of the defects and left to heal for 3 and 6 weeks. New bone formation (NBF%) and bone-implant contact (BIC%) values were evaluated by histologic and histomorphometric analyses (P < 0.05). Nanoparticles with a yield of 80.30% ± 2.14% and high encapsulation efficiency of 72.99% ± 2.20% were achieved. In all sections, osseointegration was observed, with no signs of inflammation, necrosis, or foreign body reaction. NBF% and BIC% were significantly higher in vitamin D3–loaded groups (P < 0.001). In both healing periods, the highest NBF% and BIC% have been recorded in the autograft + xenograft groups. (For the respective third and sixth weeks: the NBF% was 49.63 ± 1.53 and 74.25 ± 0.96, and BIC% was 54.26 ± 0.66 and 82.59 ± 2.09, respectively; P < 0.001). Sustained-release of vitamin D loaded into the PLA system demonstrated high biocompatibility, favorable sustained release of vitamin D3, and improved NBF% and BIC% around ti implants placed in box-shaped sheep iliac crest defects. Further investigations are required for their clinical applicability.

Stability of Implants Supported By Three Types of Bone Grafting Materials in Dogs

Background: This study was conducted to assess the stability of implants placed in a simultaneous procedure with different grafting materials (autogenous, xenogenous, and synthetic) in experimentally induced bone defects in dogs.Methods: Thirteen dogs were included and divided into three groups according to the time of sacrificing. Oversized osteotomies were prepared in the sternum, and the implants were placed in bone defects. A total of 3 to 5 implants were placed per animal. Each group of animals contained 3 subgroups according to the grafting material utilized. In subgroup 1, autograft was applied, whereas in subgroups 2 and 3, bovine bone mineral (Cerabone) and a synthetic calcium phosphate substitute (Osteon II) were employed. At the end of the specified healing periods (2 months, 4 months, or 6 months), the animals were sacrificed and the implant stability was determined through measuring the resonance frequency.Results: Forty-five integrated implants were obtained from this study and nine were lost (failure rate 17%). The two-way analysis of variance revealed no significant difference in ISQ measurements either between the bone graft materials (autogenous, xenogenous, and synthetic; P=0.950) or between the healing intervals (2 months, 4 months, and 6 months; P=0.769)Conclusions: The stability of implants augmented with autogenous, xenogenous (Cerabone) or synthetic (Osteon II) graft materials was comparable at 2, 4 and 6 months after placement. This indicates that both Cerabone and Osteon II could be considered as suitable substitutes for regeneration of bone defects to overcome the limitations of autografts.

Effect of Different Bone Grafting Materials and Mesenchymal Stem Cells on Bone Regeneration: A Micro-Computed Tomography and Histomorphometric Study in a Rabbit Calvarial Defect Model

This study evaluated the new bone formation potential of micro–macro biphasic calcium phosphate (MBCP) and Bio-Oss grafting materials with and without dental pulp-derived mesenchymal stem cells (DPSCs) and bone marrow-derived mesenchymal stem cells (BMSCs) in a rabbit calvarial bone defect model. The surface structure of the grafting materials was evaluated using a scanning electron microscope (SEM). The multipotent differentiation characteristics of the DPSCs and BMSCs were assessed. Four circular bone defects were created in the calvarium of 24 rabbits and randomly allocated to eight experimental groups: empty control, MBCP, MBCP+DPSCs, MBCP+BMSCs, Bio-Oss+DPSCs, Bio-Oss+BMSCs, and autogenous bone. A three-dimensional analysis of the new bone formation was performed using micro-computed tomography (micro-CT) and a histological study after 2, 4, and 8 weeks of healing. Homogenously porous structures were observed in both grafting materials. The BMSCs revealed higher osteogenic differentiation capacities, whereas the DPSCs exhibited higher colony-forming units. The micro-CT and histological analysis findings for the new bone formation were consistent. In general, the empty control showed the lowest bone regeneration capacity throughout the experimental period. By contrast, the percentage of new bone formation was the highest in the autogenous bone group after 2 (39.4% ± 4.7%) and 4 weeks (49.7% ± 1.5%) of healing (p < 0.05). MBCP and Bio-Oss could provide osteoconductive support and prevent the collapse of the defect space for new bone formation. In addition, more osteoblastic cells lining the surface of the newly formed bone and bone grafting materials were observed after incorporating the DPSCs and BMSCs. After 8 weeks of healing, the autogenous bone group (54.9% ± 6.1%) showed a higher percentage of new bone formation than the empty control (35.3% ± 0.5%), MBCP (38.3% ± 6.0%), MBCP+DPSC (39.8% ± 5.7%), Bio-Oss (41.3% ± 3.5%), and Bio-Oss+DPSC (42.1% ± 2.7%) groups. Nevertheless, the percentage of new bone formation did not significantly differ between the MBCP+BMSC (47.2% ± 8.3%) and Bio-Oss+BMSC (51.2% ± 9.9%) groups and the autogenous bone group. Our study results demonstrated that autogenous bone is the gold standard. Both the DPSCs and BMSCs enhanced the osteoconductive capacities of MBCP and Bio-Oss. In addition, the efficiency of the BMSCs combined with MBCP and Bio-Oss was comparable to that of the autogenous bone after 8 weeks of healing. These findings provide effective strategies for the improvement of biomaterials and MSC-based bone tissue regeneration.

REGENERATION WITH AUTOGENOUS BONE GRAFT IN ANGULAR DEFECT

Untreated periodontal disease destroys the attachment apparatus and tooth supporting tissues, resulting in tooth loss. Periodontal treatment aims to stop the progression of periodontal disease while also regenerating periodontal tissues that have been lost due to periodontal disease. Periodontal regeneration appears to occur after treatment with autogenous bone grafts, according to data from clinical and histological research. Because it contains cells that engage in osteogenesis, autogenous bone possesses osteogenic potential. Autografts are also bioabsorbable (they are eventually replaced by the patient's own bone), nonallergenic (they produce little tissue reaction without an immunological reaction), simple to utilize, and inexpensive. Around autogenous bone graft particles, rapid revascularization occurs, and the graft can release growth and differentiation agents. When compared to open flap debridement, autogenous cancellous bone from the jaw is not suited for repairing intrabony periodontal abnormalities. An autogenous cortical bone (ACB) graft derived from the surgical site close to the intraosseous defect is beneficial because it eliminates the requirement for a second surgical site for repairing intraosseous periodontal deficiencies. For tissue regeneration, many therapeutic techniques are employed. Various grafting materials, such as autografts, allografts, xenografts, and alloplasts, have been used and therapeutically utilized among them. A case report on periodontal regeneration employing autogenous bone in the treatment of a periodontal intra-bony defect in the lower left molars is presented in this study.

Evaluation of different grafting materials for alveolar cleft repair in the context of orthodontic tooth movement in rats

To minimize the postoperative risks posed by grafting autologous transplants for cleft repair, efforts are being made to improve grafting materials for use as potential alternatives. The aim of this study was to compare the bone graft quality of different bone substitutes including the gold standard autografts during the healing processes after cleft repair in the context of orthodontic treatment. In 21 Wistar rats, a complete, continuity-interrupting cleft was created. After 4 weeks, cleft repair was performed using autografts from the hips’ ischial tuberosity, human xenografts, or synthetic bone substitutes [beta-tricalcium phosphate (β-TCP)/hydroxyapatite (HA)]. After another 4 weeks, the first molar movement was initiated in the reconstructed jaw for 8 weeks. The bone remodeling was analyzed in vivo using micro-computed tomography (bone mineral density and bone volume fraction) and histology (new bone formation). All the grafting materials were statistically different in bone morphology, which changed during the treatment period. The β-TCP/HA substitute demonstrated less resorption compared to the autologous and xenogeneic/human bone, and the autografts led to a stronger reaction in the surrounding bone. Histologically, the highest level of new bone formation was found in the human xenografts, and the lowest was found in the β-TCP/HA substitute. The differences between the two bone groups and the synthetic materials were statistically significant. Autografts were confirmed to be the gold standard in cleft repair with regard to graft integration. However, parts of the human xenograft seemed comparable to the autografts. Thus, this substitute could perhaps be used as an alternative after additional tissue-engineered modification.

VESTIBULOPLASTY IN AN EXTREMELY ATROPHIC EDENTULOUS MANDIBLE USING A COMBINATION OF STRIP PALATAL GRAFT AND XENOGENEIC COLLAGEN MATRIX: A CASE REPORT

Purpose: The aim of this research was to evaluate the cumulative effect of using both epithelial autograft and xenogeneic collagen matrix as an alternative to single keratinized epithelial palatal autografts, which can prove beneficial for its reduced morbidity. Materials and methods: This study includes one female patient with an extremely atrophic mandible who requires deepening of the vestibulum in the anterior region in order to improve the stability of the removable denture. The surgical procedure included local anesthesia, one horizontal incision and a partial-thickness flap elevation. The exposed periosteum was covered by a small keratinized epithelial autograft from the hard palate at its apical aspect and a xenogeneic collagen matrix at its coronal portion. Follow up of the healing process was performed on the 7th, 14th, 30th day, after three and six months. Results: The postoperative period underwent without any complications in all areas. The healing process resulted in the formation of an additional area of keratinized mucosa - a mean gain value of 2.92 mm after six months, which led to a significant improvement of denture stability. Conclusion: The final result suggested that this technique shows great promise in compensating the disadvantages of using single grafting materials: the increased morbidity caused by the additional surgical site on the palate in the case of autografts and the greater shrinkage of the area of keratinized mucosa in a six months period when collagen matrixes are applied as a single grafting material in large edentulous areas.

Comparative study of tympanoplasty type I using periosteum versus tragal cartilage with perichondrium

Background Various grafting materials and different techniques have been used for myringoplasty. The aim of the study was to compare the result of tympanoplasty in patients with safe-type chronic suppurative otitis media using periosteum versus tragal cartilage with perichondrium grafts through pre- and postoperative clinical and audiological evaluation. Results There was statistically significant difference for mean air-bone gap for group A (23.4 dB ± 0.03 SD) when compared to group B (19.4 dB ± 4.2 SD) with P value 0.103. Also, there was statistically significant difference in the hearing gain in group A after 6 months (25.53 dB ± 6.26 SD) when compared to group B (19.63 dB ± 9.76 SD) and the P value was 0.003. Graft taken was superior in the periosteal group (95%), compared to the cartilage grafts (90%). Conclusion Tympanoplasty with periosteal graft showed better hearing results and high rates of graft taken than tragal cartilage grafts.