bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zurich Cementless Total Hip Replacement: Retrospective Evaluation of 2nd Generation Implants in 60 Dogs
Authors: GUERRERO TOMÁS G. , MONTAVON PIERRE M. 
Published: January 2009

Objective— To evaluate the results of application, and identify complications, of the 2nd generation of Zurich Cementless Total Hip Replacement (ZCTHR).Study Design— Case series.Animals— Client‐owned dogs (n=60) that had ZCTHR (n=65).Methods— Dogs with ZCTHR (2001–2003) with a minimum follow‐up ≥6 months were evaluated. Data included signalment, cup position, longest follow‐up, complications, management of complications and outcome.Results— Mean follow‐up was 22.68 months. Eleven cases (17%) had postoperative complications: femoral fracture (n=1; 1.5%), prosthesis luxation (7; 11%), cup loosening (2; 3%), and implant failure (1; 1.5%); 9 cases were successfully revised. Explantation of implants was performed in 1 case because of infection, and 1 dog was euthanatized after reluxation.Conclusions— ZCTHR can restore function in dogs affected by disabling diseases of the coxofemoral joint. The press‐fit fixation of the cup allowed for corrections in cases of incorrect positioning. Cases with aseptic loosening were revised successfully by impacting larger cups. Newer stems of this generation are shot peening treated to increase their resistance to breakage. In our cases, infection is a disastrous event, leading to implant removal. After resolution of complications, a successful final outcome was achieved in 97% of THR.Clinical Relevance— ZCTHR offers a reliable alternative for treating dogs with disabling diseases of the hip joints.
Lateral Thoracic Artery Axial Pattern Flap in Cats
Authors: BENZIONI HADAS , SHAHAR RON , YUDELEVICH SIGAL , SHIPOV ANNA , MILGRAM JOSHUA 
Published: January 2009

Objective—To describe the location of the lateral thoracic artery (LTA), determine dimensions of an axial pattern flap based on this artery, and report use of this flap in 2 cats.Study Design—Ex vivo study and case reports.Animals—Cat cadavers (n=8); cats (n=2) with thoracic limb skin defects.Methods—Dissection of the LTA was carried out on 1 side of each cadaver and the contralateral side was used for injection studies. In 4 specimens, the LTA was cannulated and injected with positive contrast material and the flap was raised and radiographed. In 4 specimens, the flap was injected with methylene blue. Adequacy of flap injection was subjectively evaluated and leakage of methylene blue from the cut edge was noted.Results—The cutaneous location of the LTA caudal to the triceps muscle was confirmed. Mean flap size was 8.7 cm × 15.5 cm for a mature, averaged‐sized cat. Perfusion of the entire flap was demonstrated and viability of the flap was confirmed in 2 clinical cases.Conclusion—The LTA flap is useful for repair of skin defects of the brachium and antebrachium in cats.Clinical Relevance—The LTA flap is an alternative technique for repair of skin defects involving the thoracic limb of cats.
Effect of Tibial Plateau Leveling Osteotomy on Femorotibial Contact Mechanics and Stifle Kinematics
Authors: KIM STANLEY E. , POZZI ANTONIO , BANKS SCOTT A. , CONRAD BRYAN P. , LEWIS DANIEL D. 
Published: January 2009

Objective—To evaluate the effects of tibial plateau leveling osteotomy (TPLO) on femorotibial contact mechanics and 3‐dimensional (3D) kinematics in cranial cruciate ligament (CrCL)‐deficient stifles of dogs.Study Design—In vitro biomechanical study.Animals—Unpaired pelvic limbs from 8 dogs, weighing 28–35 kg.Methods—Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135°. Three‐dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL‐deficient, and TPLO‐treated conditions. Repeated measures analysis of variance with a Tukey post hoc test (P<.05) was used for statistical comparison.Results—Significant disturbances to all measured contact mechanical variables were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and increased internal tibial rotation in the CrCL‐deficient stifle. No significant differences in 3D femorotibial alignment were observed between normal and TPLO‐treated stifles; however, femorotibial contact area remained significantly smaller and peak contact pressures in both medial and lateral stifle compartments were positioned more caudally on the tibial plateau, when compared with normal.Conclusion—Whereas TPLO eliminates craniocaudal stifle instability during simulated weight bearing, the procedure fails to concurrently restore femorotibial contact mechanics to normal.Clinical Relevance—Progression of stifle osteoarthritis in dogs treated with TPLO may be partly the result of abnormal stifle contact mechanics induced by altering the orientation of the proximal tibial articulating surface.
Effect of Tibial Tuberosity Advancement on Femorotibial Contact Mechanics and Stifle Kinematics
Authors: KIM STANLEY E. , POZZI ANTONIO , BANKS SCOTT A. , CONRAD BRYAN P. , LEWIS DANIEL D. 
Published: January 2009

Objective— To evaluate the effects of tibial tuberosity advancement (TTA) on femorotibial contact mechanics and 3‐dimensional kinematics in cranial cruciate ligament (CrCL)‐deficient stifles of dogs.Study Design— In vitro biomechanical study.Animals— Unpaired pelvic limbs from 8 dogs, weighing 28–35 kg.Methods— Digital pressure sensors placed subjacent to the menisci were used to measure femorotibial contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135°. Three‐dimensional static poses of the stifle were obtained using a Microscribe digitizing arm. Each specimen was tested under normal, CrCL‐deficient, and TTA‐treated conditions. Repeated measures analysis of variance with a Tukey post hoc test (P<.05) was used for statistical comparison.Results— Significant disturbances to all measured contact mechanic parameters were evident after CrCL transection, which corresponded to marked cranial tibial subluxation and internal tibial rotation in the CrCL‐deficient stifle. No significant differences in any contact mechanic and kinematic parameters were detected between normal and TTA‐treated stifles.Conclusion— TTA eliminates craniocaudal stifle instability during simulated weight‐bearing and concurrently restores femorotibial contact mechanics to normal.Clinical Relevance— TTA may mitigate the progression of stifle osteoarthritis in dogs afflicted with CrCL insufficiency by eliminating cranial tibial thrust while preserving the normal orientation of the proximal tibial articulating surface.
Marginal fit of cemented and screw‐retained crowns incorporated on the Straumann (ITI)® Dental Implant System: an in vitro study
Authors: Tosches N. A. , Brägger U. , Lang N. P. 
Published: January 2009

AbstractAim: The aim of this study was to assess the marginal fit of crowns on the Straumann (ITI)® Dental Implant System with special consideration of different casting dental materials.Material and methods: Sixty porcelain‐fused‐to‐metal crowns were fabricated: 18 crowns on standard cone abutments with an impression cylinder, partially prefabricated analogs, no coping and screw‐retained (A); 18 crowns on solid abutments without an impression device, no analogs, no coping and cemented (B); and 18 crowns on solid abutments using an impression transfer cap, an analog with a shoulder, no coping and cemented (C). In each group, six crowns were made on epoxy mastercasts (Bluestar®), six on synthetic plaster (Moldasynt®) and six on super hard stone (Fujirock®). Six additional crowns were fabricated with the transversal screw retention system onto the Octa® system with impression transfer caps, metal analogs, gold copings and screw‐retained (D). Impregum® was used as impression material. Crowns of B and C were cemented with KetacCem®. Crowns of A and D were fixed with an occlusal screw torqued at 15 N cm. Crowns were embedded, cut and polished. Under a light microscope using a magnification of × 100, the distance between the crown margin (CM) and the shoulder (marginal gap, MG) and the distance between the CM and the end of the shoulder (crown length, CL) was measured.Results: MGs were 15.4±13.2 μm (A), 21.2±23.1 μm (B), 11±12.1 μm (C) and 10.4±9.3 μm (D). No statistically significantly differences using either of the casting materials were observed. CLs were −21.3±24.8 μm (A), 3±28.9 μm (B), 0.5±22 μm (C) and 0.1±15.8 μm (D). Crowns were shorter on synthetic casting materials compared with stone casts (P<0.005).Conclusions: CMs fit precisely with both cemented and screw‐retained versions as well as when using no, partial or full analogs.
Bone quality in the midpalate for temporary anchorage devices
Authors: Wehrbein Heinrich 
Published: January 2009

AbstractObjective: The aim of the present study was to quantitatively assess the bone quality of the palatal bone from an implantologic standpoint.Material and methods: The material consisted of palatal tissue blocks of autopsy material from 22 subjects (19 male, three female), between 18 and 63 years of age. The specimens comprised the anterior part of median palate (APMP) from about 7 mm behind the incisive foramen (first premolar regions), the middle part of median palate (MPMP, second premolar region), and the posterior part of the median palate (PPMP, first molar region). They were prepared in the transversal plane using ground‐thin‐section technology. The midpalatal areas of the different parts of the palate [regions of interest (ROI) for temporary anchorage device (TAD) placement] 3 mm bilaterally to the midline were assessed with respect to hard tissue fraction to total bone volume (HTF/TBV), bone marrow fraction to total bone volume (BMF/TBV), and sutural tissue fraction to total bone volume (STF/TBV). Furthermore, age‐specific evaluation was performed: younger age group (18–25 years, n=10) and older age group (26–63 years, n=12).Results: Histomorphometric measurement showed the following results for the APMP: mean HTF/TBV, 68.57%; mean BMF/TBV, 21.38%; and mean STF/TBV, 9.96%. There were no statistically significant differences between the various tissue fractions of the APMP, MPMP, and PPMP. The younger age group showed a mean HTF/TBV of 68.88%, a mean BMF/TBV of 21.5%, and a mean STF/TBV of 9.53%. No statistically significant differences with the older age group were found.Conclusion: These results suggest that the HTF in the APMP, MPMP, and PPMP in younger as well as older adults is relatively high. Thus, good primary stability of TADs should be achieved in all parts of the adult median palate independent of age.
Bleeding on probing and pocket probing depth in relation to probing pressure and mucosal health around oral implants
Authors: Gerber J. A. , Tan W. C. , Balmer T. E. , Salvi G. E. , Lang N. P. 
Published: January 2009

AbstractObjectives: To assess the bleeding on probing (BOP) tendency and periodontal probe penetration when applying various probing forces at implant sites in patients with a high standard of oral hygiene with well‐maintained peri‐implant tissues.Material and methods: Seventeen healthy patients with excellent oral hygiene in a maintenance program after having been treated for periodontitis or gingivitis were recruited. Missing teeth had been replaced using oral implants. The BOP and probing depth (PPD) were assessed at the mid‐buccal, mid‐oral, mesial and distal aspects of the buccal surfaces of each implant. Moreover, contralateral teeth were designated and assessed for BOP and PPD in the same locations and at the same observation visits. At each visit, implants and contralateral teeth were randomly assigned to one of the standardized probing forces (0.15 or 0.25 N). The second probing force was applied at the repetition of the examination 7 days later.Results: Increasing the probing pressure by 0.1 N from 0.15 N resulted in an increase of BOP percentage by 13.7% and 6.6% for implants and contralateral teeth, respectively. There appeared to be a significant difference of the mean BOP percentage at implant and tooth sites when a probing pressure of 0.25 N was applied. A significantly deeper mean PPD at implant sites compared with tooth sites was found irrespective of the probing pressure applied.Conclusions: The results of the present study demonstrated that 0.15 N might represent the threshold pressure to be applied to avoid false positive BOP readings around oral implants. Hence, probing around implants demonstrated a higher sensitivity compared with probing around teeth.
Effect of modifications of dual acid‐etched implant surfaces on peri‐implant bone formation. Part I: organic coatings
Authors: Schliephake H. , Aref A. , Scharnweber D. , Bierbaum S. , Sewing A. 
Published: January 2009

AbstractObjective: The aim of the present study was to test the hypothesis that peri‐implant bone formation can be improved by modifying dual acid‐etched (DAE) implant surfaces using organic coatings that enhance cell adhesion and osteogenic differentiation.Material and methods: Ten adult female foxhounds received experimental titanium implants in the mandible 3 months after removal of all premolar teeth. Six types of implants were evaluated in each animal: (i) implants with a machined surface (MS), (ii) implants with a DAE surface topography, (iii) implants with an acid‐etched surface coated with RGD peptides, (iv) implants with an acid‐etched surface coated with collagen I, (v) implants with an acid‐etched surface coated with collagen I and chondroitin sulphate (CS), (vi) implants with an acid‐etched surface coated with collagen I and CS and recombinant human bone morphogenetic protein‐2. Peri‐implant bone regeneration was assessed by histomorphometry after 1 and 3 months in five dogs each by measuring bone implant contact (BIC) and the bone volume density (BVD) of the newly formed peri‐implant bone.Results: After 1 month, mean BIC was significantly higher in the coated implants group than in the MS group. There was no significant difference when mean BIC in the DAE group was compared with implants with any of the organic coatings, but the difference was significant when compared with the MS implants. Differences in mean BVD value did not reach significance between any of the surfaces. After 3 months, the same held true for the mean BIC of all the groups except for Coll I. Mean volume density of the newly formed bone was higher in all the surface modifications, albeit without statistical significance.Conclusions: It is concluded that with the exception of Coll I, the tested organic surface coatings on DAE surfaces did not improve peri‐implant bone formation when compared with the DAE surfaces but enhanced BIC when compared with the MSs.
Evaluation of a new biodegradable membrane to prevent gingival ingrowth into mandibular bone defects in minipigs
Authors: Thoma Daniel S. , Halg Gian‐Andrea , Dard Michel M. , Seibl Reinhart , Hammerle Christoph H. F. , Jung Ronald E. 
Published: January 2009

AbstractObjective: The aim of this study was to test whether a synthetic, biodegradable membrane made of polyethylene glycol (PEG) can prevent soft‐tissue ingrowth into alveolar defects.Material and methods: In each of 16 minipigs, three mandibular premolars were bilaterally extracted. Three months later, acute standardized defects (diameter 8 mm, depth 8 mm) were prepared. Four treatment modalities were randomly allocated to the defects: (1) PEG membrane plus collagen sponge, (2) polylactide (PLA) membrane plus collagen sponge, (3) collagen sponge alone, and (4) empty defect. Animals were sacrificed at 10 days (n=5), 21 days (n=5), or 2 months (n=6) after treatment. Qualitative and quantitative histological evaluations of soft‐tissue ingrowth and bone regeneration were performed on nondecalcified ground sections. For statistical analysis, the Mann–Whitney–Wilcoxon test, the Kruskal–Wallis, and the paired t‐test were applied. P‐values were adjusted using the Dunnett–Hsu adjustment.Results: At 10 days, the PEG membrane group showed the least soft‐tissue ingrowth (mean value −0.75 mm; range −1.35 to −0.10), followed by the PLA membrane group −0.18 mm (−0.80 to 0.44), the collagen group 0.04 mm (−0.65 to 0.73), and the empty defects 0.60 mm (−0.08 to 1.29). Statistically significant differences were observed between the PEG membrane group and the empty defects (P<0.05). At 21 days, the highest percentage of newly formed bone was found in the PEG membrane group (mean 28.4%; range 21.6–35.2) compared with 23.7% (16.9–30.5; PLA membrane), 15.2% (8.2–22.2; collagen group), and 21.6% (14.5–28.8; empty defects). Statistically significant differences were only found between the PEG membrane group and the collagen group (P<0.05). At 2 months, the tested parameters revealed no statistically significant differences between the groups.Conclusion: The experimental PEG membrane applied in the present study successfully prevented collapse of the covering soft tissues to a degree similar to the PLA membrane. The combination of a collagen sponge and the PEG membrane showed the least soft‐tissue ingrowth at 10 days and promoted more bone formation at 21 days.
Pore characteristics of bone substitute materials assessed by microcomputed tomography
Authors: Klein Marcus , Goetz Hermann , Pazen Sabine , Al‐Nawas Bilal , Wagner Wilfried , Duschner Heinz 
Published: January 2009

AbstractObjectives: Pore configurations of alloplastic biomaterial scaffolds play a major role for new bone formation in vivo. Current studies on characteristics of pores in bone substitute materials focus on individual particles or single blocks. Thus, three‐dimensional (3‐D) architecture of particle aggregates, representing the clinical relevant in vivo situation is not adequately taken into account. The aim of this study was the visualization and quantification of pore properties, both of the scaffold structure of single particles as well as of the micro‐morphology of complex 3‐D aggregated particle‐conglomerates.Material and methods: In model experiments, standardized plexiglass cylinders were stuffed with commercial bone substitute material particles with diverse chemical composition (HA, β‐TCP, HA‐SiO2, HA‐β‐TCP, bioactive glass), origin (phycogenic, bovine, synthetic) and granulation (50 μm–2000 μm). Analogue to establish procedures for native (human) bone samples, non‐fixed bone substitute materials were scanned by high‐resolution microcomputed tomography. In addition to computer animated two‐dimensional and 3‐D reconstruction of the samples, median pore thickness and pore size distribution were determined. Materials representative for their chemical constitution were documented by SEM imaging.Results: Investigated specimens significantly were different in micro‐morophology and pore properties, ranging from highly porous to rather solid. The most voluminous pores were localized interparticularly. Within one product line, the determined pore properties showed a significant correlation with single particle grain sizes.Conclusion: The generation and interpretation of μ‐CT based 3‐D pore models can provide further insight into the expected osteoconduction dynamics and therefore might serve as a basis for further modifications of scaffold size and geometry as well as for further invasive studies on the biological behaviour of the scaffolds.
Human osteoclast formation and activity on an equine spongy bone substitute
Authors: Perrotti Vittoria , Nicholls Brian M. , Piattelli Adriano 
Published: January 2009

AbstractObjectives: The aim of the present study was to evaluate the in vitro formation and activity of human osteoclasts (OCLs) generated on a new type of xenograft for bone substitution, an equine spongy bone.Material and methods: Peripheral blood mononuclear cells from healthy volunteers were used to generate OCLs in vitro in the presence of macrophage colony stimulating factor (M‐CSF) and receptor activator of NF‐κB ligand (RANKL) on bovine bone slices (positive control) and equine spongy bone. Morphological and biochemical methods were used to assess OCLs formation and activity.Results: Cells generated after 21 days of culture on equine spongy bone showed similar morphology to those on the positive control and displayed typical OCL markers and features, indicating that this material supported OCL formation. Moreover, these cells were functionally active on equine spongy bone with statistically significant differences compared with the control in the release of tartrate‐resistant acid phosphatase (TRAcP5b) at days 14 and 21 of culture. With regard to the resorption, on equine bone, OCLs formed smaller discontinuous island‐like lacunae rather than the typical lobulated, tracking resorption lacunae observed on the control.Conclusions: This study enables clinicians to tailor the usage of equine spongy bone and presents a model, which can be applied to the preclinical assessment of bone substitute material's resorbability and resorption rates.
Ectopic bone formation after implantation of a slow release system of polylactid acid and rhBMP‐2
Authors: Gruber R. , Weich H.A. , Dullin C. , Schliephake H. 
Published: January 2009

AbstractObjectives: The present study was conducted to test the hypothesis that preshaped polylactic acid (PLA) implants loaded with recombinant human bone morphogenic protein 2 (rhBMP‐2) can induce bone formation in a rat ectopic model.Materials and methods: Two groups of porous cylindrical poly‐dl‐lactic acid implants of 8‐mm diameter were produced by gas foaming with CO2, incorporating 48 and 96 μg rhBMP‐2, respectively, into each implant. Blank PLA implants were used as controls. The release of BMPs and the induction of alkaline phosphatase were assessed in vitro. Osteoinduction in vivo was tested by insertion of 15 implants from each group into the gluteal muscles of Wistar rats. Five implants from each group were retrieved after 6, 13 and 26 weeks and assessed using flat panel volume detector computed tomography and light microscopy.Results: Both groups of implants showed increased release of rhBMP‐2 during the first 24–48 h, with a slightly higher amount being released from the implants with 48 μg. Release during subsequent intervals was <100 ng/72 h in the low‐concentration group and >100 ng in the group with 96 μg rhBMP‐2. Implants with 95 μg rhBMP‐2 exhibited bone formation in vivo on the outside of the implants across the observation period of 26 weeks with invasion of bone into the pores, whereas implants with 48 μg rhBMP‐2 failed to induce the formation of bone tissue. No bone formation was found in the control implants.Conclusions: The results suggest that release rates of rhBMP‐2 for ectopic bone induction have to be >100 ng/72 h to maintain the osteoinductive activity of the tested porous PLA implants. This slow release system may have impact on alveolar bone augmentation procedures when used as individually preformed osteoinductive implants.