ABSTRACT
Precision measurement of nonlinear observables is an important goal in all facets of quantum optics. This allows measurement-based non-classical state preparation, which has been applied to great success in various physical systems, and provides a route for quantum information processing with otherwise linear interactions. In cavity optomechanics much progress has been made using linear interactions and measurement, but observation of nonlinear mechanical degrees-of-freedom remains outstanding. Here we report the observation of displacement-squared thermal motion of a micro-mechanical resonator by exploiting the intrinsic nonlinearity of the radiation-pressure interaction. Using this measurement we generate bimodal mechanical states of motion with separations and feature sizes well below 100 pm. Future improvements to this approach will allow the preparation of quantum superposition states, which can be used to experimentally explore collapse models of the wavefunction and the potential for mechanical-resonator-based quantum information and metrology applications.
ABSTRACT
STATEMENT OF PROBLEM: A complete understanding of dental implant prognosis requires better knowledge of the bone anatomy after implant healing. Such baseline data are necessary to compare against load-induced changes in anatomy. PURPOSE: The purpose of this article is to describe and compare measures of implant support (percentage [%] integration and percentage [%] bone area) for various implants in baboon jaws after healing times of 3 and 6 months. MATERIAL AND METHODS: Commercially pure titanium (cpTi) and titanium alloy (Ti-alloy) screw-shaped implants were placed in the posterior jaws of 9 female baboons after 2 months of postextraction healing. Specimens were harvested after 3 months (5 baboons: 8 cpTi, 7 Ti-alloy) and after 6 months (4 baboons: 8 cpTi, 8 Ti-alloy). Each implant provided 6 polished horizontal sections for data collection, which was accomplished from digitized images with the IMAGE analysis system (reliability at 1.6%). Three- and six-month data for each parameter were compared with the use of ANOVA (P<.01). RESULTS: The results revealed a significant increase in the % integration (cpTi 39.1 to 56.2; Ti-alloy 40.0 to 55.2) and the % bone area (cpTi 38.8 to 47.9; Ti-alloy 38.9 to 49.2) from 3 to 6 months for both implants. This significant increase was also true for comparisons by jaw for each implant material (P<.01 for overall and by jaw comparisons). CONCLUSION: A time-dependent increase in jawbone anchorage was measured in this nonhuman primate population, and it was shown that the 6-month maxillary data were comparable to the 3-month mandibular data. These results lend support to the clinical strategy of waiting longer to load implants in the maxilla.
Subject(s)
Dental Implants , Jaw/pathology , Alloys , Analysis of Variance , Animals , Dental Alloys , Dental Implantation, Endosseous , Dental Implants/classification , Female , Follow-Up Studies , Image Processing, Computer-Assisted , Mandible/pathology , Mandible/surgery , Maxilla/pathology , Maxilla/surgery , Models, Animal , Orthognathic Surgical Procedures , Osseointegration , Papio , Titanium , Wound HealingABSTRACT
Exposure of the distal internal carotid artery (ICA) above the level of the second cervical vertebra can be difficult and often require maneuvers such as division of the digastric muscle or mandibular subluxation. These techniques increase exposure but may not provide adequate access. We report a series of eight cases in which vertical division of the mandibular ramus provided access of the ICA up to the base of the skull. Over the last 10 years, eight patients underwent vertical ramus osteotomy (VRO) to aid in distal ICA exposure. Preoperative arteriography revealed ICA lesions within 1.5 cm of the skull base. Indications for surgery were compelling and included gunshot wounds to zone III of the neck (n = 2), transient ischemic attack (n = 2), and preocclusive stenosis (n = 4). VRO was performed through a standard vertical neck incision and was created from the depth of the sigmoid notch to the angle of the mandible after elevating the masseter muscle from the bone. Miniature titanium plates were used to reapproximate the mandible after endarterectomy (n = 5), bypass (n = 2), or arterial repair (n = 1). We found that VRO provides reliable exposure of the distal ICA up to the base of the skull. Unlike mandibular subluxation, it requires no pre-incision preparation, thus mandibulotomy can be performed after carotid artery dissection has begun, and may even be avoided. VRO is especially useful when carotid artery pathology unexpectedly extends beyond the usual field of exposure. Work on the carotid artery at the skull base is associated with significant complications and should be reserved for compelling indications.
Subject(s)
Carotid Artery, Internal/surgery , Mandible/surgery , Osteotomy/methods , Adult , Aged , Blood Vessel Prosthesis Implantation , Bone Plates , Carotid Artery Injuries/surgery , Carotid Stenosis/surgery , Endarterectomy, Carotid , Female , Humans , Male , Middle Aged , Postoperative Complications , Wounds, Gunshot/surgeryABSTRACT
In an effort to better understand the supporting anatomy for unloaded endosseous dental implants, this study focused on the histomorphometric analysis of 3 different types of implants placed into non-human primate jaws and allowed to heal for 6 months. This report describes data from 24 screw-type dental implants placed in edentulated (2 months healing time) posterior arches of 4 adult female baboons. Three different implants were placed and allowed to heal for 6 months prior to processing for evaluation: commercially pure titanium (n = 8), titanium alloy (n = 8), and titanium plasma-sprayed (n = 8). Circumferential bone-implant interface sampling from 6 regions along the entire length of each implant was obtained for evaluation of percent bone-implant contact (%BIC) and percent bone area (%BA), within 3 mm of the implant. Data were collected (reliability of 1.6% for both parameters) and analyzed by an observer blinded to implant material using IMAGE analysis software for differences between jaws, implant biomaterials, and jaw/biomaterial (analysis of variance, pairwise comparison using least squares method with Bonferroni adjustment). The results indicated that the overall mean %BIC was 55.8 and mean %BA was 48.1. Maxillary and mandibular differences for both parameters were statistically significantly different: %BIC in maxilla 50.8, in mandible 60.8; %BA in maxilla 43.6, in mandible 52.6 (both significant at the P < .05 level). The biomaterial analyses revealed no significant differences between the different implants for %BIC or %BA. The trend observed--that mandibular values were greater than maxillary values for the overall jaw comparisons--was found to be consistent at the jaw/biomaterial level, although the small sample size limited statistical power. These data, along with data from a previous 3-month study, provide insight into baseline supporting anatomy for dental implants.
Subject(s)
Dental Implantation, Endosseous , Dental Implants , Jaw, Edentulous/pathology , Alloys , Analysis of Variance , Animals , Biocompatible Materials/chemistry , Coated Materials, Biocompatible/chemistry , Dental Alloys/chemistry , Dental Prosthesis Design , Female , Follow-Up Studies , Image Processing, Computer-Assisted , Jaw, Edentulous/surgery , Least-Squares Analysis , Mandible/pathology , Mandible/surgery , Maxilla/pathology , Maxilla/surgery , Models, Animal , Observer Variation , Papio , Reproducibility of Results , Sample Size , Single-Blind Method , Surface Properties , Titanium/chemistry , Wound HealingABSTRACT
The purpose of this study was to evaluate an intraoral, nontooth-borne, submucosal distraction appliance in the pig mandible from a clinical, radiographic, and histologic perspective. Intraoral distraction appliances were fabricated, tested for strength, and then adapted and rigidly fixated to the mandibles of three growing miniature Yucatan pigs. A bicortical osteotomy was performed on the right side of the mandible, and a buccal and lingual corticotomy on the left. Two amalgam markers were placed on each side of the osteotomy/corticotomy sites as references. Measurements were taken to evaluate the length and vector of the distraction site, and radiographs were obtained perioperatively. After a latency period of 5 days, distraction was commenced and continued for 13 days at a rate of 1 mm/day. Clinical evidence of distraction was apparent in all cases, with resulting Class III skeletal deformities. Distraction progressed further for the corticotomy sides than the osteotomy sides because of distraction device failure. Radiographic examination revealed increased bone density at the periphery of the distracted callus, with less density apparent centrally. Histologic examination showed fibrous connective tissue in the center of the callus, with cartilage and osteoid formation at the periphery. Bone formation was parallel to the vectors of distraction in all cases. This study confirms that the use of a modified intraoral appliance for distraction osteogenesis is feasible. Use of this device overcomes many of the problems associated with extraoral devices and may have clinical applications.
Subject(s)
Mandible/surgery , Osteogenesis, Distraction/instrumentation , Animals , Equipment Design , Evaluation Studies as Topic , Feasibility Studies , Jaw Fixation Techniques/instrumentation , Orthodontic Appliances , Pilot Projects , Swine , Swine, MiniatureABSTRACT
Mechanical testing of the implant-tissue interface has been the focus of numerous investigations concerning the anchorage capacity of implants. The purpose of this study was to measure reverse-torque failure after 6 months of healing for three different biomaterials in the posterior jaws of four adult female baboons. The animals had all of their posterior teeth surgically extracted and, following 10 weeks of healing, 7 implants were placed in each quadrant. The biomaterials included titanium plasma-sprayed surfaces, titanium-aluminum-vanadium surfaces (both 3.8 mm x 10 mm), and a commercially pure titanium surface (3.75 mm x 10 mm). After 6 months, torque data were collected using a counterclockwise computerized torque driver and were analyzed by repeated measures analysis of variance for differences related to biomaterial, jaw, and biomaterial/jaw. Post-hoc Tukey Kramer analysis was also performed for within-group differences (alpha = .05 level). The biomaterial comparison revealed a significant difference between the titanium plasma-sprayed and the combined commercially pure titanium/titanium -aluminum-vanadium groups (analysis of variance, Tukey Kramer, P < .05). The jaw comparison showed no significant difference, although the data suggest that higher forces may be required for mandibular torsional failure. The biomaterial/jaw comparison revealed that jaw differences for the mean values of commercially pure titanium and titanium-aluminum-vanadium implants were greater than jaw differences for mean values of titanium plasma-sprayed implants, although these differences were not statistically significant. Because of the lack of correlation between single-cycle biomechanical tests and clinical performance, it is necessary to be selective in assigning usefulness to data of this type.
Subject(s)
Dental Implantation, Endosseous , Dental Implants , Alloys , Analysis of Variance , Animals , Biocompatible Materials/chemistry , Biomechanical Phenomena , Dental Alloys/chemistry , Dental Prosthesis Design , Dental Restoration Failure , Disease Models, Animal , Female , Follow-Up Studies , Mandible/surgery , Maxilla/surgery , Osseointegration , Papio , Surface Properties , Titanium/chemistry , Torque , Wound HealingABSTRACT
A search for an abundant and economical source of isoflavones, particularly genistein, led to the discovery that the erythromycin-producing organism Saccharopolyspora erythraea also produces this promising new cancer-prevention agent. Erythromycin fermentation is a large-scale, soybean-based process used world-wide for the commercial production of this medically important antibiotic. Results from this study indicate that genistin (the glucoside form of genistein), which is added to the fermentation in the soybean media, was converted to genistein through the action of a beta-glucosidase produced by the organism. Genistein was co-extracted with erythromycin from the fermentation broth, then separated from erythromycin during the second step of the purification process for the production of erythromycin.
Subject(s)
Isoflavones/isolation & purification , Isoflavones/metabolism , Saccharopolyspora/metabolism , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Culture Media/metabolism , DNA Topoisomerases, Type II/metabolism , Electrophoresis, Agar Gel , Erythromycin/biosynthesis , Fermentation , Genistein , Isoflavones/chemistry , Mass Spectrometry , Molecular Structure , Glycine max/metabolism , beta-Glucosidase/metabolismABSTRACT
OBJECTIVE: This study evaluated the biologic result of forces induced by a misfitting prosthetic superstructure on implants placed in a New Zealand white rabbit tibia model. STUDY DESIGN: Nine rabbits had two dental implants placed in both right and left proximal tibias. After 6 weeks, one animal was sacrificed for baseline integration data, and the remaining animals had fitting or misfitting prosthetic superstructures attached to the implants for 12 weeks. Implants were evaluated clinically, radiographically, and histomorphometrically at the scanning electron microscopic level. RESULTS: No clinical, radiographic, or histomorphometric evidence exists of integration failure with implants subjected to superstructure strain, although bone remodeling is noted. CONCLUSIONS: Given the limitations of sample size, animal model used, duration of prosthetic superstructure attachment, and loading confounders possible, the study of prosthetic framework misfit must be evaluated with another animal model, such as an intraoral primate model, to determine the relationship between clinical performance and histologic findings.
Subject(s)
Bone Remodeling/physiology , Dental Implants , Dental Prosthesis Design , Osseointegration/physiology , Adaptation, Physiological , Animals , Female , Models, Biological , Prosthesis Fitting , Rabbits , Stress, Mechanical , TibiaABSTRACT
Important to the understanding of the dynamics associated with dental implant anchorage over time is a knowledge of the supporting anatomy for common endosseous implants prior to being placed into function. This study followed 20 screw-shaped dental implants placed in edentulated (2 months' healing time) posterior jaws of five adult female baboons. Implants made of three biomaterials were placed and allowed to heal for 3 months prior to processing for evaluation. Percentage integration and bone area data from six horizontal sections along the entire length of each implant were collected and analyzed for differences between jaws, implant biomaterials, jaw/biomaterial, and sections of the implants (ANOVA, pairwise comparison using LSM with Bonferroni adjustment). The results indicated that overall mean percentage integration was 46.5 and mean percentage bone area was 39.9. Maxillary and mandibular differences for both parameters were statistically different (integration: maxillary = 38.1%, mandibular = 56.7%; bone area: maxillary = 35.8%, mandibular = 44.9%; both were significant at the P < .05 level). The biomaterial analyses revealed significant differences for percentage integration between the metal implants and the hydroxyapatite-coated implant (commercially pure titanium = 39.1%, titanium-aluminum-vanadium = 40.0%, hydroxyapatite-coated = 61.5%), but no such difference was noted for percentage bone area (commercially pure titanium = 38.8%, titanium-aluminum-vanadium = 38.9%, hydroxyapatite-coated = 42.3%). Discussion of the relative importance of the two parameters highlights the fact that resistance to functional loads requires establishing and then maintaining an adequate volume of bone, which may have a functionally specific structure based on the mechanical properties of the local jaw environment.
Subject(s)
Dental Implantation, Endosseous , Dental Implants , Dental Prosthesis Design , Mandible/pathology , Maxilla/pathology , Alloys , Analysis of Variance , Animals , Biocompatible Materials/chemistry , Dental Alloys/chemistry , Durapatite/chemistry , Female , Follow-Up Studies , Jaw, Edentulous/pathology , Jaw, Edentulous/surgery , Mandible/surgery , Maxilla/surgery , Osseointegration , Papio , Stress, Mechanical , Surface Properties , Titanium/chemistry , Wound HealingABSTRACT
Implant failure as a consequence of prosthetic loading following clinical determination of successful stage I healing is poorly understood. A basic premise of accepted prosthetic protocol is passive connection of multiunit prostheses to the implant support. To better understand mechanical factors related to implant failure, this basic passivity premise was experimentally tested prior to study of functional loading research. The purpose of this preliminary study was to measure the bone response around implants placed in the mandible of baboons that supported prostheses exhibiting two levels of fit and not loaded occlusally. Screw-retained prostheses that exhibited a mean linear distortion of 38 microns and 345 microns made up the fit and misfit groups respectively. The results failed to distinguish a difference in bone response between the two levels of prosthetic fit. Although the finding can be argued as a sample size limitation, the data strongly suggest an opposite response than is clinically expected and, consequently, does not warrant the use of additional animals in this initial study. Because the design of this study does not mimic the clinical application of misfitting prostheses (where dynamic functional loads are superimposed with misfit loads), it cannot be inferred that, in clinical application, fit does not alter the osseointegrated interface. Ongoing investigation of failure due to nonpassive connections under dynamic loading conditions of mastication will help clarify the clinical significance of passivity.
Subject(s)
Dental Prosthesis, Implant-Supported , Dental Restoration Failure , Dental Stress Analysis , Osseointegration , Analysis of Variance , Animals , Compressive Strength , Denture, Partial, Fixed , Disease Models, Animal , Female , Papio , Tensile StrengthABSTRACT
Torque failure for endosseous implants has been used as a biomechanical measure of anchorage, though the significance of such data is not known. A practical understanding of the resistance to torque failure of implant-tissue interfaces at stage 2 surgery would help in assigning torque levels for implant abutment-screw fastening. The purpose of this study was to measure torque failure levels of commercially pure (CP) titanium, Ti-6Al-4V, hydroxyapatite-coated (HA-coated) screw-shaped implants placed into the maxillae and mandibles of baboons. Implants identical in size were placed into the edentulous posterior maxillae and mandibles of six female baboons (n = 37 each group) using a standardized surgical protocol. Reverse-torque data were collected at postinsertion time intervals ranging from 3 to 4 months using a counterclockwise torque driver and the data were analyzed (repeated measures ANOVA) for torque differences related to time, biomaterial, and jaw. The HA-coated implants exhibited significantly greater torque-removal values compared to both metallic implants (HA: 186.0 Ncm [50.1]; Ti-6Al-4V: 78.6 Ncm [18.1]; CP Ti 74.0 Ncm [24.4]). Analysis of torque interactions with jaw showed no significant difference; however, the mandible was found to be greater than the maxilla in torque resistance for all groups tested. Understanding the risks in inferring animal data to human application, the clinical implications of these data suggest that the recommended torque level of 35 Ncm for abutment fastening may provide a margin of safety for most implants of similar design and material as used in this study.(ABSTRACT TRUNCATED AT 250 WORDS)
Subject(s)
Dental Abutments , Dental Implantation, Endosseous , Dental Implants , Dental Prosthesis Design , Alloys , Animals , Dental Alloys/chemistry , Durapatite/chemistry , Equipment Safety , Female , Jaw, Edentulous/surgery , Mandible/surgery , Materials Testing , Maxilla/surgery , Papio , Prosthesis Failure , Rotation , Stress, Mechanical , Surface Properties , Titanium/chemistryABSTRACT
A quantitative measure of implant stability would be beneficial to decision-making regarding the status of the bone anchorage around an implant. The Periotest device has been reported to provide such a measure, but the in vivo data are incomplete and inconclusive in support of this claim. The purpose of this study was to determine in an in vivo model the relationship between Periotest values (PTV), three different implant biomaterials, and torque to failure. A total of 79 screw-shape implants made of commericially pure titanium, titanium alloy, and HA-coated alloy were evaluated in the posterior maxillary and mandibular quadrants of six female baboons following healing for 3 to 4 months. At uncovering, the implants were tested with the Periotest device and torqued to failure using an electronic torque driver. Analysis of the PTV-biomaterial relationship revealed no significant difference among the implants based on the biomaterial (P = .7453). Analysis of PTV-torque revealed a significant relationship (P = .0117), however, the association between PTV and torque was not strong and does not explain 92% of the variation between the parameters (Pearson correlation .2823, R2 = .08).
Subject(s)
Dental Implants , Dental Prosthesis Retention , Analysis of Variance , Animals , Biomechanical Phenomena , Dental Alloys , Dental Stress Analysis , Disease Models, Animal , Durapatite , Female , Linear Models , Papio , Prosthesis Failure , TitaniumABSTRACT
This paper describes a modification of the combined bilateral sagittal split osteotomy and total subapical osteotomy procedure; a representative case treated with this approach is presented. In addition, diagnostic and treatment planning considerations for the comprehensive surgical-orthodontic therapy of individuals presenting with differential sagittal discrepancy between the mandibular corpus and symphysis are discussed, along with limitations of diagnostic criteria commonly used in cephalometric appraisal of the facial soft tissue outline.
Subject(s)
Malocclusion, Angle Class II/surgery , Mandible/surgery , Osteotomy/methods , Retrognathia/surgery , Adult , Cephalometry , Female , Humans , Mandible/abnormalities , Orthodontics, Corrective/methods , Patient Care PlanningABSTRACT
A study was undertaken to evaluate the integration of endosseous implants in rabbit tibias that had received a tumoricidal dose of radiation. The effect of hyperbaric oxygen on integration in this compromised situation was also evaluated. Despite clinical and radiographic evidence of success of all implants, there was a significant decrease in amount of histologic bony integration of implants placed in the tibias that had received radiation therapy when compared to contralateral control implants. Adjunctive hyperbaric oxygen therapy significantly improved the amount of histologic integration of implants placed within the radiated tibias evaluated at 10 and 16 weeks after placement. Hyperbaric oxygen was also associated with better soft tissue wound healing in the radiated surgical site. Increased integration time significantly improved the amount of histologic integration in the animals that did not receive hyperbaric oxygen.
Subject(s)
Bone and Bones/physiopathology , Bone and Bones/radiation effects , Hyperbaric Oxygenation , Osseointegration , Prostheses and Implants , Animals , Bone and Bones/diagnostic imaging , Bone and Bones/pathology , Bone and Bones/surgery , Durapatite , Equipment Design , Equipment Failure , Hydroxyapatites , Incidence , Rabbits , Radiation Dosage , Radiography , Surgical Wound Dehiscence/etiology , Tibia , Time Factors , Wound HealingABSTRACT
The dental profession has in the past overreacted to anecdotal reports of both positive and negative outcomes involving implants. Because implant complications usually involve multiple variables, it is necessary to isolate these variables as much as possible when structuring a study to assess implant success vs failure. The methodology used in a study of Omniloc implants is reported, including detailed criteria for patient exclusion, patient demographics, statistical method, measurement indices, control procedures, and success criteria.