AutoBT: A new Paradigm in Periodontal regeneration

Background: Autogenous bone is an ideal material for the reconstruction of hard tissue defects, because it promotes osteogenesis, osteo-induction and osteo-conduction. The use of AutoBT, a novel bone grafting material produced from autogenous teeth, resulted in excellent bone healing based on an analysis of its inorganic components, surface structure and histologic evidence of the healing process.Materials & Methods: Ten sites were included using the following inclusion criteria. Inclusion criteria: One or more sites showing intra-bony defect with probing pocket depth (PPD) ≥ 5mm, clinical attachment loss of ≥ 3mm, 2 or 3 wall intra-bony defects with radiographic defect of size ≥ 3 mm & in same patient mobile teeth indicated for extraction. In test group, among 5 sites, regenerative treatment was performed using tooth as autograft along with chorion membrane & in control group, 5 sites were treated with demineralized freeze-dried bone allograft (DFDBA) with chorion membrane. Clinical parameters such PPD, CAL were evaluated at baseline, 3 & 6 months & radiographic parameters at baseline & after 6 months of treatment.Results: The patients treated by tooth as autoBT material with chorion membrane showed non- significant results to DFDBA with chorion membrane in intra-bony defects in all the clinical parameters. So AutoBT can be used as a useful alternative to DFDBA in periodontal regenerative therapy for intra-bony defects.

Negative Effect of Rapidly Resorbing Properties of Bioactive Glass-Ceramics as Bone Graft Substitute in a Rabbit Lumbar Fusion Model

BACKGROUND: Bioactive glass-ceramics have the ability to directly bind to bones and have been widely used as bone graft substitutes due to their high osteoconductivity and biocompatibility. CaO-SiO2-P2O5-B2O3 glass-ceramics are known to have good osteoconductivity and are used as bone graft extenders. METHODS: This study aimed to evaluate the effects of the resorbing properties of glass-ceramics in bone fusion after producing and analyzing three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with high osteoconductivity that had enhanced resorption by having an increased B2O3 content. The three types of CaO-SiO2-P2O5-B2O3 glass-ceramics with B2O3 contents of 8.0, 9.0, and 9.5 weight % were designated and grouped as P20B80, P10B90, and P5B95, respectively. Glass-ceramic types were tested for fusion rates and bone formation by employing the lumbar 5-6 intertransverse process fusion model in 51 New Zealand male rabbits. Bioactivity was assessed by soaking in simulated body fluid (SBF). RESULTS: In vitro study results showed sufficient hydroxycarbonate apatite layer formation occurred for P20B80 in1 day, for P10B90 in 3 days, and for P5B95 in 5 days after soaking in SBF. For the rabbit lumbar spine posterolateral fusion model, the autograft group recorded a 100% fusion rate with levels significantly higher than those of P20B80 (29.4%), P10B90 (0%), and P5B95 (14.3%), with high resorbing properties. Resorbing property differences among the three glass-ceramic groups were not significant. Histological results showed new bone formation confirming osteoconductivity in all three types of glass-ceramics. Radiomorphometric results also confirmed the resorbing properties of the three glass-ceramic types. CONCLUSIONS: The high resorbing properties and osteoconductivity of porous glass-ceramics can be advantageous as no glass-ceramics remain in the body. However, their relatively fast rate of resorption in the body negatively affects their role as an osteoconductive scaffold as glass-ceramics are resorbed before bony fusion.

Morphological study of bone cranial in athymic mice / Estudio morfológico de hueso craneal en ratones atímicos

The aim of our research was to create an osteogenic unit in the skulls of athymic mice; however, the first challenge we faced was to find sufficient and adequate data that would allow us to determine the morphological, immunohistochemical and microtopographical characteristics that could be used as normality standards in athymic mice skulls and, hence, a reference in the event of achieving the formation of de novo bone using the osteogenic unit we proposed. Knowing the normal bone morphology in the skull of athymic mice was a necessary precondition to develop subsequently an osteogenic unit possessing the Osteogenesis, Osteoinduction and Osteoconductivity that could be compared versus those in the normal bone during its formations and remodeling processes. Therefore, we conducted a pilot study to determine bone morphological characteristics in the skull of athymic mice by means of specific histological staining: hematoxylin-eosin and Von Kossa, for osteoid tissue and mineralized bone, and Masson Tri-chrome for ossified areas. We also use immunohistochemistry to detect bone formation markers: alkaline phosphatase resulting from osteoblastic activity stimulation, type 1 collagen a bonematrix structural protein; Osteopontine, a protein specifically synthesized by osteoblasts that favors cell proliferation and remodeling in bone defects; Osteocalcine, a peptide hormone produced by osteoblasts during bone formation; and, Runx 2, a transcription factor expressed by stem cells which stimulates bone differentiation. Likewise, we used electron microscopy on the newly formed tissue to determine the presence of organic deposits, such as calcium, phosphate and magnesium in bone tissue.

Propusimos la realización de una unidad osteogénica a desarrollar en cráneo de ratones atímicos, Sin embargo, nos enfrentamos al reto de encontrar datos que nos determinaran cuales eran las características morfológicas, inmunohistoquímicas y micro-topográficas del cráneo de estos ratones atímicos, que nos sirvieran como referencia de normalidad y tener un punto de comparación, en caso de que pudiéramos lograr la formación de hueso de novo, a partir de la unidad osteogénica que propusimos. El objetivo, de conocer la morfología del hueso normal de cráneo de ratones atímicos, fue desarrollar posteriormente una unidad osteogénica que reuniera las características de Osteogénesis, Osteoinducción y Osteoconducción, y, compararlas contra las que tiene dicho hueso normal durante su proceso de formación y remodelación. Así, realizamos un estudio piloto donde establecimos características morfológicas de hueso del cráneo de ratones atímicos, a través de tinciones histológicas específicas, con hematoxilina-eosina y von Kossa para buscar tejido osteoide y hueso mineralizado y Tricrómico de Massón para observar zonas osificadas. Además, analizamos el tejido óseo a través de inmunohistoquímica, con la finalidad de buscar marcadores de formación ósea como fosfatasa alcalina que es resultado del estímulo de la actividad osteoblástica; colágena 1, la cual es una proteína estructural de la matriz ósea; osteopontina, proteína sintetizada específicamente por osteoblastos que favorece la proliferación celular y la remodelación en defectos óseos; osteocalcina hormona peptídica producida por los osteoblastos durante la formación ósea y Runx 2 Factor de transcripción expresado por las células progenitoras que estimula la diferenciación ósea. Además, sometimos el tejido óseo a microscopía electrónica para determinar la presencia de depósitos de compuestos como calcio, fósforo y magnesio.

Histomorphometric evaluation of bone healing with natural calcium carbonatederived bone substitutes in rat calvarial defect / 대한치주과학회지

PURPOSE: This study investigated the osteoconductivity of natural calcium carbonate-derived bone substitutes, hen eggshell (ES), and compared with those of commercial bone substitutes. MATERIALS AND METHODS: Osseous defects created in the rat calvaria were filled with particulated ES(ES-1), ES with calcium-deficient hydroxyapatite surface layer (ES-2), Biocoral(Inoteb, France), and Bio-Oss(Geistlich Pharma, Wolhusen, Switzerland). After 4 and 8 weeks of healing, histomorphometic analysis was performed to evaluate the amount of newly formed mineralized bone area (NB%). RESULTS: Histologic and histomorphometric analysis showed new bone formation and direct bony contact with the grafted materials in all groups. At 4 weeks, Biocoral group showed greater NB% compared to Bio-Oss and ES-1 groups (P<0.05). At 8 weeks, Biocoral and ES-2 groups showed significantly greater NB% compared to Bio-Oss group (P<0.05). CONCLUSION: These results indicate that natural calcium carbonate-derived bone substitutes with microporous calciumdeficient hydroxyapatite surface layer may be an effective materials treating osseous defects.

Histomorphometric evaluation of bone healing with fully interconnected microporous biphasic calcium phosphate ceramics in rabbit calvarial defects / 대한치주과학회지

PURPOSE: The purpose of this study was to histomorphometrically evaluate the osteoconductivity of a new biphasic calcium phosphate ceramics with fully interconnected microporous structure. MATERIAL AND METHODS: Osseous defects created in the rabbit calvaria were filled with four different bone graft substitutes. Experimental sites were filled with a new fully interconnected microporous biphasic calcium phosphate with(BCP-2) or without(BCP-1) internal macropore of 400micrometer in diameter. MBCP(Biomatlante, France) and Bio-Oss(Geistlich Pharma, Switzerland) were used as controls in this study. Histomorphometric evaluation was performed at 4 and 8 weeks after surgery. RESULT: In histologic evaluation, new bone formation and direct bony contact with the graft particles were observed in all four groups. At 4 weeks, BCP-1(15.5%) and BCP-2(15.5%) groups showed greater amount of newly formed mineralized bone area(NB%) compared to BO(11.4%) and MBCP(10.3%) groups. The amounts of NB% at 8 weeks were greater than those of 4 weeks in all four groups, but there was no statistically significant differences in NB% between the groups. CONCLUSION: These results indicate that new bone substitutes, BCP with interconnected microporous structure and with or without internal macroporous structures, have the osteoconductivity comparable to those of commercially available bone substitutes, MBCP and Bio-Oss.

Effect of deproteinized bovine bone mineral soaked in inorganic polyphosphate on bone regeneration / 대한치주과학회지

This study was performed to evaluate the effect of deproteinized bovine bone mineral soaked in inorganic polyphosphate on bone regeneration in the calvaria of rabbit in the procedure of guided bone regeneration with titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. The rabbits were divided into four groups. Control group used TR-ePTFE membrane filled with deproteinized bovine bone mineral, experimental group I used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 4% inorganic polyphosphate, experimental group II and III used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 8% or 16% inorganic polyphosphate respectively. After decortication in the calvaria, GBR procedure was performed on 8 rabbits with only TR-ePTFE membrane or titanium reinforced ePTFE membrane filled with deproteinized bovine bone mineral soaked in inorganic polyphosphate. The animals were sacrificed at 4 weeks, and 8 weeks after the surgery. Non-decalcified specimens were processed for histologic analysis, and new bone formation was assessed by histomorphometric as well as statical analysis. 1. Both control group and experimental group demonstrated increasing of new bone formation until 8weeks. 2. At 8 weeks, experimental group I and group II showed the significant difference compared to control group in new bone formation. Especially experimental group II showed the most increasing of new bone formation. 3. The higher concentration of inorganic polyphosphate filled, the more volume of bone formation promoted, but experimental group III did not reveal significant difference compared to contol group. 4. Deproteinized bovine bone mineral did not resorbed at all until 8 weeks. These results suggest that inorganic polyphosphate has a promoting effect on bone regeneration, possibly by enhancing osteoconductivity of the carrier and by increasing osteoinductivity of the defected alveolar bone tissue, but not as we respect.

Evaluation of Osteosynthesis in CaO-SiO2-P2O5-B2O3 Glass-ceramics by Posterolateral Fusion of Rabbit Lumbar vertebrae / 대한척추외과학회지

STUDY DESIGN: A comparative in vivo study between ceramics with different compositions. OBJECTIVES: To compare the biodegradation and osteoconduction properties of CaO-SiO2- P2O5- B2O3 glass-ceramics and Cerabone(R)-AW. Summary of Literature Review: Bioglass ceramics can be used as bone graft substitutes. However, no study has been undertaken to investigate the possibility of CaO-S i O2-P2O5-B2O3 glass-ceramics as a bone graft substitute. MATERIALS AND METHODS: Porous CSPB2 implants (44.07% CaO, 40.28% SiO2, 8.1% P2O5 and 5.0% B2O3), porous CSPB3 implants (43.76% CaO, 43.41% SiO2, 4.05% P2O5 and 7.5% B2O3) and porous Cerabone(R)-AW were prepared by the polymer sponge method. Single-level posterolateral spinal fusions were performed on sixty New Zealand white male rabbits. The animals were divided into four groups (9 of autograft, 17 per 3 kind of porous implant group) according to the implant material used: autograft, CSPB2, CSPB3 and Cerabone(R)-AW. Radiographs were performed every two weeks. All animals were sacrificed 12 weeks after surgery. Manual palpation and uniaxial tensile strength were determined. The proportion of the area occupied by the ceramics in the final compared to the initial radiographs was calculated. Decalcified and undecalcified histological sections were evaluated by light microscopy. RESULTS: Fifty one rabbits were evaluated. The union rates were 100 (9 out of 9), 80 (8 out of 8), 81.1 (9 out of 11) and 90.9% (10 out of 11) in the autograft, Cerabone(R)-AW, CSPB2 and CSPB3 groups, respectively. The proportion of the area occupied by Cerabone(R)-AW (90.8 % +/- 14.0) was significantly higher than for CSPB2 (73.1% +/- 11.5) and CSPB3 (73.5% +/- 10.0)(p=0.0011). The mean values of the tensile strengths of Cerabone(R)-AW (214. +/- 57.3N), CSPB2 (214. +/- 57.3 N) and CSPB3 (217 +/- 70.1 N) were not significantly different (p>0.05). CONCLUSION: CSPB2 and CSPB3 had similar tensile strengths and fusion rates of the fusion masses as those of Cerabone(R)-AW; however, they degraded more rapidly than Cerabone(R)-AW. These findings suggest that CSPB2 and CSPB3 grafts can be used as a more ideal new bone graft substitutes than Cerabone(R)-AW.

Evaluation of Biodegradation and Osteosynthesis in CaO-SiO2-B2O3 Glass-ceramics by Posterolateral Fusion of Rabbit Lumbar vertebrae / 대한정형외과학회잡지

PURPOSE: To compare the biodegradation and osteoconduction properties of CaO-SiO2-B2O3 glass-ceramics (CS10B), hydroxyapatite(HA), and tricalcium phosphate (TCP). MATERIALS AND METHODS: Porous CS10B implants were prepared by the polymer sponge method. Single-level posterolateral spinal fusions were performed on thirty rabbits. The animals were divided into three groups by implant material: HA, TCP and CS10B. Radiographs were performed every two weeks. All animals were sacrificed 12 weeks after surgery. The proportion of the area occupied by the ceramicsin the final over the initial radiographs was calculated. Uniaxial tensile strength was determined from 7 cases in each group. RESULTS: The proportion of the area occupied by HA (88.7+/-16.1%) was significantly higher than the others (p<0.05), and the proportion of the area occupied by CS10B (28.2+/-9.3%) was significantly lower than those of HA and TCP (37+/-9.6%) (p<0.05). The mean values of the tensile strengths of HA (191.4+/-33.5 N) and CS10B (182.7+/-19.9 N) were significantly higher (p<0.05) than those of TCP (141.1+/-28.2 N). CONCLUSION: CS10B had similar tensile strengths of the fusion masses as HA, however, it degraded more rapidly than HA or TCP. These findings suggest CS10B grafts as possible bone replacement materials.

Chemical, Structural & Osteoconductive Properties of Mineralized Porcine Cancellous Bone / 대한정형외과연구학회지

PURPOSE: The purpose of this study is to determine the efficacy of bioactive hydroxyapatite obtained from the porcine cancellous bone for the treatment of bone defect and nonunion. MATERIALS AND METHODS: Porcine cancellous bones were heat-treated at 1300degrees C for 2 hours. The chemical compositions, calcium to phosphate ratio and microstructures of mineralized porcine bone were examined. For in vivo implantation, bone defects were made on the anteromedial aspects of proximal tibia in 7 beagle dogs and theses artificial bones were inserted. Plain X-ray was taken at every 2 weeks interval for radiologic evaluation. At 12 weeks, specimens were evaluated histologyically with hematoxylin and eosin stain. RESULTS: The composition and morphology of mineralized porcine cancellous bone were similar to those of heat-treated human cancellous bone. Radiographs showed union at the host bone-bone block interfaces. At 12 weeks, all uniform and substantial new bone formation were observed. CONCLUSION: This mineralization technique has several advantages such as no disease transmission, no immune reaction, excellent biocompatibility, and cost-effectiveness. Consequently, mineralized porcine cancellous bone showed an effective osteoconductivity.