Bone Regeneration of Hydroxyapatite with Granular Form or Porous Scaffold in Canine Alveolar Sockets.

This study was undertaken to assess bone regeneration using hydroxyapatite (HA). The primary focus was comparison of bone regeneration between granular HA (gHA) forms and porous HA (pHA) scaffold. The extracted canine alveolar sockets were divided with three groups: control, gHA and pHA. Osteogenic effect in the gHA and pHA groups showed bone-specific surface and bone mineral density to be significantly higher than that of the control group (p<0.01). Bone volume fraction, bone mineral density, and amount of connective tissue related to disturbing osseointegration of the gHA group was higher than in the pHA group. Quantity of new bone formation of the pHA group was higher than that of the gHA group. This study demonstrated that gHA and pHA are potentially good bone substitutes for alveolar socket healing. For new bone formation during 8 weeks' post-implantation, HA with porous scaffold was superior to the granular form of HA.

Comparison of the degree of hip joint luxation induced by the lateral and medial surgical approaches used to generate vascular deprivation-induced necrosis of the femoral head in rats.

UNLABELLED: The rat model that is commonly used to study femoral head osteonecrosis involves the induction of osteonecrosis by surgery employing a lateral approach to the hip joint. However, this approach induces hip joint luxation, which means it is difficult to determine whether the osteonecrosis arises because of the vascular deprivation or because of the hip joint luxation. Whether or not femoral head osteonecrosis can be induced by the medial approach to the hip joint, which does not generate hip joint luxation, was assessed. MATERIALS AND METHODS: twelve 6-month-old F344 rats were subjected to the lateral or medial approach. RESULTS: four weeks after surgery, the lateral approach group showed luxation upon radiography, but the medial approach group did not. Histopathology revealed both groups exhibited osteonecrosis of the femoral head. CONCLUSION: a surgically induced model of femoral head osteonecrosis that employs the medial approach is a more effective model than that using the lateral approach.

Treatment of hydrocephalus with high-pressure valve ventriculoperitoneal shunt in a dog.

A 5-month-old male Maltese with right-sided circling, deafness, and blindness was presented. A diagnosis of communicating hydrocephalus was made. A ventriculoperitoneal shunt was implanted and the cerebrospinal fluid was drained by using an adjustable valve type (Medtronic Strata). The valve was set at 2.5 (135-155 mmH2O). This was done to prevent the possibility of an overdrainage-induced collapse of the brain parenchyma, which can occur rarely when canine hydrocephalus is treated by using a low-pressure valve. Computed tomography performed 6 weeks and 1 year after surgery revealed the ventricles had decreased in size. Thus, a high-pressure valve used during the treatment of hydrocephalus was able to maintain normal intracranial pressure.

Scintigraphic evaluation of TPLO and CTWO in canine osteoarthritis.

The objective of this study was to evaluate the bone uptake of the bone-seeking radionuclide (99m)technetium-methylene diphosphonate ((99m)Tc-MDP) in order to examine and compare the clinical efficacies of tibial plateau leveling osteotomy (TPLO) and cranial tibial wedge osteotomy (CTWO) for the correction of experimentally induced cranial cruciate ligament (CrCL) transected stifle. Fifteen healthy adult beagle dogs, weighing between 10 and 15 kg, were used for this study. Dogs were assigned to TPLO (n=5), CTWO (n=5) or a control sham group (n =5) and screened with both physical and complete orthopedic examinations. Left CrCLs were transected and two of the three groups were stabilized using TPLO and CTWO. Scintigraphic evaluation of the stifle was performed before TPLO or CTWO surgical repair of the left limb and again at 4, 8 and 12 weeks after surgery. Bone uptake values at 8 and 12 weeks for the TPLO and CTWO groups were not significantly different from their preoperative values, but these differed significantly from the control group at 4, 8 and 12 weeks (p<0.01). No significant differences were found between TPLO and CTWO values. In summary, the relative efficacy of CTWO approximately equals that of TPLO. Moreover, the results of this study confirmed that TPLO and CTWO inhibited the progression of osteoarthritis in CrCL-deficient dogs.

Comparison of immediate and delayed implantation using the square-threaded and resorbable-blasted-media-treated surface implant system.

A variety of dental implant systems are now available that optimize bone-to-implant contact. The present study was performed to compare the outcomes, by measuring peri-implant osseointegration, following immediate and delayed insertion of square-threaded and resorbable-blasted-media (RBM)-treated surface implants in the dog's mandible. Three dogs were used and four implants were inserted in each dog. All implants were used for histological and histomorphometrical evaluations. The contact lengths and osseointegrated areas following immediate implantation were 74.99% and 56.08%, and those following delayed implantation were 78.22% and 66.08%, respectively. The implantation method in dogs using the square-threaded and RBM treated surface implant system achieved higher percentages of osseointegration than previously reported and the two implantation techniques did not differentially influence osseointegration. Thus, immediate implantation of this implant system, which minimizes the number of surgical procedures, is an optimal clinical method to replace extracted teeth in dogs.

A case of maloccluded incisor teeth in a beaver: castor canadensis.

A three-year-old female beaver (Castor canadensis) was referred to the Veterinary Teaching Hospital of Chungbuk National University. It had been raised in the Cheong-ju zoo and had a history of malocclusion caused by improper feeding. General anesthesia was induced, and preoperative intraoral dental radiographs of the rostal maxillary and mandibular dentition were taken and lateral and ventrodorsal extraoral radiographs of the cheek teeth were also taken. The radiographs were negative for apical pathology and revealed a normal appearance of the cheek teeth. The lesion was likely to be related to the excessive length of the maxillary and mandibular incisors. Odontoplasty was performed to reduce overgrowth of the crowns of the incisors. Sequential transverse sections were removed until the crown was reduced by approximately its original length. The pulp chamber was not approached during the operation, as confirmed by postoperative intraoral radiographic evaluation of the incisors. Recovery from anesthesia was uneventful and the beaver returned to normal masticatory activities immediately after the operation.

Flow injection microbial trichloroethylene sensor.

A flow type microbial biosensor for direct measurement of trichloroethylene (TCE) was developed. The unique features of this novel microbial sensor were the use of the TCE degrading bacterium Pseudomonas aeruginosa JI104, the electrical detection of the chloride ion released by microbial degradation, and flow cell made of glass. Glass cell was used in order to suppress adsorption of TCE and made a closed reaction cell. Vaporization of TCE during the measurement was prevented using closed flow cell. The performance of the sensor was evaluated from following aspects; such as pH of the carrier solution, amount of the immobilized microbe, flow rate and injection volume. The sensor signals were linearly proportional to the concentration of TCE in the range from 0.03 to 2 mgl(-1), which is suitable for the determination of suspected samples to be drinkable water or not. The sensor performance was checked on the real sample, and this system showed good response in ground water, indicating its applicability for the on line monitoring at TCE contaminated areas or hazardous sites.