Raman study of the repair of surgical bone defects grafted with biphasic synthetic microgranular HA + β-calcium triphosphate and irradiated or not with λ780 nm laser

The treatment of bone loss due to different etiologic factors is difficult, and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (～960, ～1,070, and ～1,077 cm^?1) and organic (～1,454 and ～1,666 cm^?1) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of killing (15 and 30 days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of group Clot, the defect was filled only by blood clot; on group Laser, the defect filled with the clot was further irradiated. On animals of groups Biomaterial and Laser?+?Biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ780 nm, 70 mW, Φ?～?0.4 cm², 20 J/cm² session, 140 J/cm² treatment) in four points around the defect at 48-h intervals and repeated for 2 weeks. At both 15th and 30th day following killing, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensities of both inorganic and organic contents were higher on group Laser?+?Biomaterial. It is concluded that the use of laser phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of calcium hydroxyapatite measured by Raman spectroscopy.     

Effects of laser irradiation (670-nm InGaP and 830-nm GaAlAs) on burn of second-degree in rats

This study investigated the effects of 670-nm indium gallium phosphide (InGaP) and 830-nm gallium aluminum arsenide (GaAlAs) laser therapy on second-degree burns induced on the back of Wistar rats. Sixty-three male Wistar rats were anesthetized, and second-degree burns were made on their back. The animals were then divided randomly into three groups: control (C), animals treated with 670-nm InGaP laser (LIn), and animals treated with 830-nm GaAlAs laser (LGa). The wound areas were removed after 2, 6, 10, 14, and 18 days of treatment and submitted to structural and morphometric analysis. The following parameters were studied: total number of granulocytes and fibroblasts, number of newly formed blood vessels, and percentage of birefringent collagen fibers in the repair area. Morphometric analysis showed that different lasers 670-nm InGaP and 830-nm GaAlAs reduced the number of granulocytes and an increase of newly formed vessels in radiated lesions. The 670-nm InGaP laser therapy was more effective in increasing the number of fibroblasts. The different treatments modified the expression of VEGF and TGF-β1, when compared with lesions not irradiated. The different types of light sources showed similar effects, improved the healing of second-degree burns and can help for treating this type of injury. Despite the large number of studies with LLTI application in second-degree burns, there is still divergence about the best irradiation parameters to be used. Further studies are needed for developing a protocol effective in treating this type of injury.     

Prosthetic Improvement of Pronounced Buccally Positioned Zygomatic Implants: A Clinical Report

This report presents a prosthetic technique for the improvement of surgically positioned, buccally placed zygomatic implants with the use of custom abutments for improved retention screw position and an esthetic implant reconstruction. The patient presented four zygomatic implants with pronounced buccal inclination. The anterior implants were inclined toward the location where the anterior artificial teeth should be placed during rehabilitation. As the manufacturer does not provide angulated abutments, we attempted the waxing and overcasting of a prosthetic abutment, repositioning the access holes of the prosthetic screws to a more palatal position. This clinical report demonstrates that abutment customization could be an interesting way to relocate the access holes of the prosthetic screws in cases of zygomatic implants with pronounced buccal inclination.     

In vivo X-ray cine-tomography for tracking morphological dynamics

Scientific cinematography using ultrafast optical imaging is a common tool to study motion. In opaque organisms or structures, X-ray radiography captures sequences of 2D projections to visualize morphological dynamics, but for many applications full four-dimensional (4D) spatiotemporal information is highly desirable. We introduce in vivo X-ray cine-tomography as a 4D imaging technique developed to study real-time dynamics in small living organisms with micrometer spatial resolution and subsecond time resolution. The method enables insights into the physiology of small animals by tracking the 4D morphological dynamics of minute anatomical features as demonstrated in this work by the analysis of fast-moving screw-and-nut–type weevil hip joints. The presented method can be applied to a broad range of biological specimens and biotechnological processes.The best method to study morphological changes of anatomic features and physiological processes is to observe their dynamics in 4D, that is, in real time and in 3D space. To achieve this we have developed in vivo X-ray cine-tomography to gain access to morphological dynamics with unrivaled 4D spatiotemporal resolution. This opens the way to a wide range of hitherto inaccessible, systematic investigations of small animals and biological internal processes such as breathing, circulation, digestion (1), reproduction, and locomotion (2).At the micrometer resolution range, state-of-the-art optical imaging techniques can achieve high magnifications to visualize tissues and even individual cells for 4D studies. These methods however are confined to transparent or fluorescent objects, or are limited either by low penetration depth <1 mm or poor time resolution (3). For optically opaque living organisms X-ray imaging methods are highly appropriate due to the penetrating ability of the radiation. Modern synchrotron radiation facilities provide brilliant and partially coherent radiation suitable for high-resolution volume imaging methods such as X-ray computed microtomography (SR-µCT). For static specimens SR-µCT has proven to be a powerful tool to study small animal morphology in 3D (4–6). The benefits of various physical contrast mechanisms, high spatial resolution, and short measuring times, as well as enormous sample throughput compared with laboratory X-ray setups, have led to its widespread use in life sciences.Real-time in vivo X-ray imaging with micrometer spatial resolution was realized so far by recording time sequences of 2D projection radiographs of different organisms (1, 6, 7), providing time information about functional dynamics but losing any information about the third spatial dimension.Recently, 4D in vivo X-ray experiments have been performed to study cell migration in frog embryos (8, 9) using tomographic sequences of a few seconds exposure time per tomogram interrupted by longer nonexposure time slots. In this way the authors followed relatively slow dynamics and morphological changes during embryonic development with 2-µm resolution over total time intervals of several hours. The fastest 4D time series yet reported were realized with a temporal resolution of 0.5 s and spatial resolution of 25 µm (10), applied to a living caterpillar used as test specimen for imaging, but without any analysis of dynamics.In this paper, we demonstrate the quantitative 4D investigation of morphological dynamics by in vivo X-ray 4D cine-tomography, introduced here as the combination of ultrafast SR-µCT and motion analysis procedures. Using this approach allows us to investigate previously inaccessible 3D morphological dynamics in small animals, presently with feature sizes in the micrometer range and with temporal resolution down to a few tens of milliseconds. In the past, ultrafast in vivo imaging was hardly possible for such applications, due to the strongly competing requirements for simultaneous high contrast, high signal-to-noise ratio (SNR), and concurrent low radiation dose, as well as the need for simultaneous high spatial resolution and maximum temporal resolution.In the following we describe how in vivo X-ray 4D cine-tomography meets the above challenges by optimizing image contrast, SNR, and spatial and temporal resolution in the ultrafast SR-µCT system and by establishing a dedicated data analysis pipeline, all within a unified framework (Fig. S1). We demonstrate the potential of the technique by investigating morphological dynamics in fast-moving weevils, focusing here on the exoskeletal joints.