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.
Animals ; Bone Resorption ; Bone Substitutes/adverse effects/*therapeutic use ; Ceramics/adverse effects/*therapeutic use ; Electric Conductivity ; Lumbosacral Region/*surgery ; Male ; Rabbits ; Spinal Fusion/*methods

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.
Animals ; Autografts ; Bone Regeneration ; Ceramics ; Humans ; Lumbar Vertebrae* ; Male ; Microscopy ; New Zealand ; Palpation ; Polymers ; Porifera ; Rabbits ; Spinal Fusion ; Tensile Strength ; Transplants

PURPOSE: Studies to determine the relation between oxygen tension and outcome in cardiac arrest survivors treated with therapeutic hypothermia (TH) are lacking. We investigated the relation of time-weighted mean oxygen tension (TWMO2) and outcome in cardiac arrest survivors treated with TH. METHODS: This was a retrospective observational study including 177 out-of-hospital cardiac arrest (OHCA) survivors. The patients were divided into four categories according to quartile values of TWMO2. The primary outcome was neurologic outcome at discharge and the secondary outcome was all cause in-hospital mortality. We assessed neurologic outcome using the Cerebral Performance Categories (CPC) at hospital discharge. Neurologic outcome was dichotomised as either good neurologic outcome (CPC1 and CPC2) or poor neurologic outcome (CPC 3 to 5). The odds ratio with 95% confidence interval (CI) was estimated. RESULTS: The median value of PaO2 was 139(104.5-170.0) mmHg. Among a total of 1,239 PaO2 values, 22(1.8%) values were hypoxia (<60 mmHg) and 16(1.3%) values were hyperoxia (>300 mmHg). Results of univariate logistic regression analysis showed a significantly low odds ratio for poor neurologic outcome [0.353(95% CI, 0.133-0.938) and 0.321(95% CI, 0.121-0.850), respectively] and for in-hospital mortality [0.338(95% CI, 0.132-0.870) and 0.387(95% CI, 0.154-0.975), respectively] for the third quartile and the fourth quartile. However, results of multivariate logistic regression analysis showed no significant relation between TWMO2 and outcomes. CONCLUSION: In OHCA survivors treated with TH, time-weighted oxygen tension did not show an association with neurologic outcome and in-hospital mortality.
Anoxia ; Heart Arrest ; Hospital Mortality ; Humans ; Hyperoxia ; Hypothermia* ; Logistic Models ; Observational Study ; Odds Ratio ; Out-of-Hospital Cardiac Arrest* ; Oxygen* ; Retrospective Studies ; Survivors*

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.
Animals ; Bone Regeneration ; Bone Substitutes ; Durapatite ; Lumbar Vertebrae* ; Polymers ; Porifera ; Rabbits ; Spinal Fusion ; Tensile Strength ; Transplants

PURPOSE: To evaluate the possibility of using porous beta-calcium pyrophosphate (beta-CPP) as a bone graft substitute by comparing its osteoconduction and degradation with porous hydroxyapatite (HA). MATERIALS AND METHODS: Porous HA and porous beta-CPP were implanted in the proximal tibia of 7 dogs. Two animals were sacrificed at 8weeks and 5 animals were sacrificed at 20 weeks after surgery. Radiographs and histologic sections were evaluated. RESULTS: The mean period required for the radiolucent zone to disappear was 7.1+/-1.1 weeks in HA and 6.4+/-1.1 weeks in beta-CPP. By serial radiography, resorption was more prominent in porous beta-CPP than in porous HA at 8 weeks (p=0.04) and at 20 weeks. The proportion of bony tissue in the pore was 16.8% in HA and 29.7% in -CPP. The proportion of pores with bony tissue was 70.2% in HA and 62.5% in beta-CPP at 8 weeks. CONCLUSION: In beta-CPP, the new bone growth was as vigorous as in HA, but the degradation was more rapid than in HA. These results suggest that beta-CPP is a more ideal new bone graft substitute.
Animals ; Bone Development ; Bone Regeneration ; Dogs ; Durapatite ; Radiography ; Tibia ; Transplants*

PURPOSE: To evaluate the osseointegration of different dense ceramics. MATERIALS AND METHODS: Twenty-eight New Zealand white male rabbits were divided into 4 groups by implant materials: Cerabone(R)-AW, CaO-SiO2- B2O3 glass ceramics (CS10B), CaO-SiO2- B2O3 glass (CS5B glass) and Cerabone(R)- A W + A l2O3 glass ceramics. We implanted the dense ceramics into the tibia of rabbits with external fixator and checked the radiographs every 4 weeks. The union rate, histology and SEM were evaluated 8 weeks after surgery. RESULTS: The union rates were 85.7% (6 of 7) in Cerabone(R)-AW, 85.7% (6 of 7) in CS10B, 71.4% (5 of 7) in CS5B glass and 28.6% (2 of 7) in Cerabone(R)-AW+Al2O3 by simple radiographs. The union rates of Cerabone (R)-AW and CS10B were statistically higher than that of Cerabone(R)-AW+Al2O3 (p=0.031). Histologically, the Cerabone(R)-AW had fused with tibia without biodegradation, CS10B, CS5B glass had fused with tibia in some portion but resorbed in others. Cerabone(R)-AW+Al2O3 had not fused with bony tissue. CONCLUSION: We confirmed the osseointegration and insolubility of Cerabone(R)-AW. We also confirmed the osseointegration and partial solubility of CaO-SiO2-B2O3 glass ceramics. These findings suggest that Cerabone (R)-AW can be used as an insoluble artificial bone and CaO-SiO2-B2O3 glass ceramics as biodegradable bone replacement materials.
Bone Substitutes ; Ceramics* ; External Fixators ; Glass ; Humans ; Male ; New Zealand ; Osseointegration* ; Rabbits ; Solubility ; Tibia