Home About us Contact
|
Home About us Contact | ||
|
|
||
Digital Subtraction Radiography (digital + subtraction_radiography)
Selected AbstractsEffect of bone chip orientation on quantitative estimates of changes in bone mass using digital subtraction radiographyJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2003André Mol Objectives:, To assess the effect of the orientation of arbitrarily shaped bone chips on the correlation between radiographic estimates of bone loss and true mineral loss using digital subtraction radiography. Methods:, Twenty arbitrarily shaped bone chips (dry weight 1,10 mg) were placed individually on the superior lingual aspect of the interdental alveolar bone of a dry dentate hemi-mandible. After acquiring the first baseline image, each chip was rotated 90 degrees and a second radiograph was captured. Follow-up images were created without the bone chips and after rotating the mandible 0, 1, 2, 4, and 6 degrees around a vertical axis. Aluminum step tablet intensities were used to normalize image intensities for each image pair. Follow-up images were registered and geometrically standardized using projective standardization. Bone chips were dry ashed and analyzed for calcium content using atomic absorption. Results:, No significant difference was found between the radiographic estimates of bone loss from the different bone chip orientations (Wilcoxon: P > 0.05). The correlation between the two series of estimates for all rotations was 0.93 (Spearman: P < 0.05). Linear regression analysis indicated that both correlates did not differ appreciably ( and ). Conclusion:, It is concluded that the spatial orientation of arbitrarily shaped bone chips does not have a significant impact on quantitative estimates of changes in bone mass in digital subtraction radiography. These results were obtained in the presence of irreversible projection errors of up to six degrees and after application of projective standardization for image reconstruction and image registration. [source] Influence of interleukin-1 gene polymorphism on periodontal regeneration in intrabony defectsJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2003M. Christgau The aim of this controlled retrospective study was to evaluate the influence of an IL-1 gene polymorphism on the clinical and radiographic healing outcomes of GTR therapy. The study included 47 adult periodontitis patients with 94 deep intrabony defects treated by GTR using different membrane materials. The following clinical parameters were recorded at baseline and 12 months after surgery: papillary bleeding index (PBI), gingival recession (REC), probing pocket depth (PPD), clinical attachment level (CAL), and the vertical relative attachment gain (V-rAG). Bone changes in the defect regions due to GTR therapy were quantitatively evaluated using digital subtraction radiography (DSR). Polymorphisms of the IL-1A gene at position ,,889 and of the IL-1B gene at position +,3953 were analyzed by PCR. Statistical analysis was performed using the Mann,Whitney-U and the Wilcoxon-Signed-Rank tests (, = 0.05). The study comprised 19 IL-1 genotype positive (IL-1 +) patients and 28 IL-1 genotype negative (IL-1 ,) patients. Twelve months after GTR therapy, both patient groups revealed statistically significant PPD reductions and CAL gain [median (25/75% percentiles)]: ,PPD [IL-1 + : 4.0 (2.5/5.0) mm; IL-1- : 3.8 (3.0/4.9) mm], ,CAL [IL-1 + : 3.5 (3.0/4.8) mm; IL-1 ,: 3.0 (1, 2/4, 5) mm]. V-rAG amounted to 60.0 (47.7/78.6)% in IL-1 + patients and 53.1 (43.4/81.9)% in IL-1 , patients. Both patient groups showed significant bone density gain in 40% (IL-1 +) and 43.6% (IL-1 ,) of the initial defect area due to GTR. Neither the clinical nor the radiographic healing parameters revealed any statistically significant differences in the GTR healing outcome between IL-1 + and IL-1 , patients. In conclusion, these 12-month findings indicate that the IL-1 gene polymorphism has no influence on the clinical and radiographic regeneration results following GTR therapy. [source] Immunization of Macaca fascicularis against experimental periodontitis using a vaccine containing cysteine proteases purified from Porphyromonas gingivalisMOLECULAR ORAL MICROBIOLOGY, Issue 3 2007R. C. Page Introduction:, Periodontitis is a common infectious disease to which Porphyromonas gingivalis has been closely linked, in which the attachment tissues of the teeth and their alveolar bone housing are destroyed. We conducted a study to determine if immunization using a purified antigen could alter the onset and progression of the disease. Methods:, Using the ligature-induced model of periodontitis in Macaca fascicularis, we immunized five animals with cysteine protease purified from P. gingivalis and used an additional five animals as controls. Alveolar bone loss was measured by digital subtraction radiography. Results:, Immunization induced high titers of specific immunoglobuin G serum antibodies that were opsonic. Total bacterial load, levels of P. gingivalis in subgingival plaque and levels of prostaglandin E2 in gingival crevicular fluid were significantly reduced. Onset and progression of alveolar bone loss was inhibited by approximately 50%. No manifestations of toxicity were observed. Conclusions:, Immunization using a purified protein antigen from P. gingivalis inhibits alveolar bone destruction in a ligature-induced periodontitis model in M. fascicularis. [source] Radiographs in periodontal disease diagnosis and managementAUSTRALIAN DENTAL JOURNAL, Issue 2009EF Corbet Abstract Radiographs are an integral component of a periodontal assessment for those with clinical evidence of periodontal destruction. A close consideration of the current approach to periodontal diagnosis compatible with the current classification of periodontal diseases reveals that radiographs only inform with respect to diagnosis for a small proportion of conditions. The area in periodontal assessment in which radiographs play a pivotal role is in treatment planning. A variety of radiographic exposure types assist in the development of periodontal treatment plans. This "therapeutic yield" can be achieved by panoramic oral radiographs supplemented by selective intra-oral views. Digital panoramic oral radiographs viewed on screen appear to offer advantages over printouts or films. Newer imaging approaches, such as cone-beam computed (digital volume) tomography, may come to show some usefulness but experience has shown that digital subtraction radiography will probably remain a research tool without much clinical application. [source] Anorganic porous bovine-derived bone mineral (Bio-Oss®) and ePTFE membrane in the treatment of peri-implantitis in cynomolgus monkeysCLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2003Søren Schou Abstract: The purpose of the present study was to evaluate the effect of anorganic porous bovine-derived bone mineral (Bio-Oss®) and expanded polytetrafluoroethylene (ePTFE) membrane in the treatment of peri-implantitis. A total of 64 implants with a titanium plasma-sprayed (TPS) surface was inserted in eight cynomolgus monkeys (Macaca fascicularis). After a 3-month healing period with plaque control, experimental peri-implantitis characterized by a bone loss of 4,6 mm was induced during a period of 9,18 months. Surgical treatment involving Bio-Oss+membrane, Bio-Oss, membrane, or a conventional flap procedure (control) only was carried out. The animals were sacrificed six months after treatment. Evaluation by clinical parameters, radiography including quantitative digital subtraction radiography, histology, and stereology demonstrated healthy peri-implant tissue irrespective of the applied surgical procedure. However, the amount of re-osseointegration and the total amount of bone (Bio-Oss and regenerated bone) were significantly higher in defects treated with membrane-covered Bio-Oss as compared with the other three treatment procedures. A mean bone-to-implant contact of 36% was obtained within defects treated with membrane-covered Bio-Oss. The corresponding values for the three other treatment procedures were 13,23%. The Bio-Oss particles were in general highly integrated within the regenerated bone, but the particles in the occlusal part of the defects were entirely surrounded by connective tissue irrespective of membrane coverage. The present study demonstrates that surgical treatment involving Bio-Oss covered by an ePTFE membrane is a useful treatment modality of experimental peri-implantitis around implants with a TPS surface in cynomolgus monkeys. However, the treatment outcome is not as encouraging as seen with membrane-covered autogenous bone graft particles documented in a study with same experimental design. Résumé Le but de l'étude présente a été d'évaluer l'effet d'un minéral osseux bovin poreux et anorganique (Bio-Oss®) et d'une membrane en téflon lors du traitement de la paroïmplantite. Soixante-quatre implants avec une surface plasma-spray en titane (TPS) ont été insérés chez huit singes Macaca fascicularis. Après une période de guérison de trois mois avec contrôle de la plaque dentaire, une paroïmplantite expérimentale caractérisée par une perte osseuse de 4 à 6 mm a été induite pendant une période de 9 à 18 mois. Le traitement chirurgical comprenant le Bio-Oss® et la membrane, le Bio-Oss®, la membrane, ou un processus de lambeau conventionnel (contrôle) ont été effectués. Les animaux ont été tués six mois après le traitement. L'évaluation par les paramètres cliniques, la radiographie incluant la radiographie de soustraction, l'histologie et la stéréologie ont mis en évidence des tissus paroïmplantaires sains quel que soit le processus chirurgical utilisé. Cependant la quantité de ré-ostéoïntégration et la quantité totale d'os (Bio-Oss®+ os régénéré) étaient significativement plus importantes dans les lésions traitées par Bio-Oss® recouvert de membrane comparée aux trois autres processus chirurgicaux. Un contact moyen os-implant de 36% a été obtenu à l'intérieure d'une lésion traitée par Bio-Oss® recouvert par une membrane. Les valeurs correspondantes pour les trois autres processus s'étalaient de 13 à 23%. Les particules de Bio-Oss®étaient en général très bien intégrées dans l'os régénéré, mais les particules dans la partie occlusale des lésions étaient entièrement entourées par du tissu conjonctif qu'il y ait ou non recouvrement par une membrane. Cette étude démontre que le traitement chirurgical impliquant le Bio-Oss® recouvert par une membrane en téflon est une modalité de traitement utile de la paroïmplantite autour des implants avec une surface TPS chez le Macaca fascicularis. Cependant le traitement n'est pas aussi encourageant que celui aperçu avec des greffes de particules d'os autogène recouvertes par une membrane qui avait été mis en évidence dans une étude utilisant le même modèle expérimental. Zusammenfassung Das Ziel der vorliegenden Studie war, den Effekt von anorganischem porösem bovinem Knochenmineral (Bio-Oss®) und expandiertem Polytetrafluoroethylene (ePTFE)-Membranen bei der Behandlung von Peri-Implantitis zu untersuchen. Insgesamt wurden 64 Implantate mit einer titanplasmabeschichteten Oberfläche (TPS) bei 8 Cynomolgus Affen (Macaca fascicularis) eingesetzt. Nach einer Heilungszeit von 3 Monaten mit Plaquekontrolle wurde eine experimentelle Peri-Implantitis, charakterisiert durch einen Knochenverlust von 4-6mm, über einen Zeitraum von 9 bis 18 Monaten induziert. Folgende chirurgische Massnahmen wurden durchgeführt: Bio-Oss+Membran, Bio-Oss, Membran oder konventionelle Lappenchirurgie (Kontrolle). Die Tiere wurden 6 Monate nach der Behandlung geopfert. Die Untersuchung mittels klinischer Parameter, Radiographie inklusive quantitative digitale Subtraktionsradiographie, Histologie und Stereologie zeigte gesunde peri-implantäre Gewebe, egal welche chirurgische Massnahme angewendet wurde. Jedoch war das Ausmass der Re-Osseointegration und die totale Menge an Knochen (Bio-Oss und regenerierter Knochen) bei den Defekten, welche mit Bio-Oss und Membran behandelt worden waren, signifikant grösser als bei den drei anderen Behandlungsgruppen. Bei den Defekten, welche mit Membran und Bio-Oss behandelt wurden, konnte ein Knochen-Implantat-Kontakt von 36% erreicht werden. Die entsprechenden Werte für die drei anderen Behandlungsgruppen betrugen 13-23%. Die Bio-Oss Partikel waren generell gut in den regenerierten Knochen integriert, nur die Partikel im okklusalen Bereich der Defekte waren komplett von Bindegewebe umgeben, egal ob sie mit einer Membran abgedeckt waren oder nicht. Die vorliegende Studie demonstriert, dass die chirurgischen Behandlung mit Bio-Oss, welches mit einer ePTFE-Membran bedeckt wird, eine brauchbare Behandlungsmodalität für die experimentelle Peri-Implantitis um Implantate mit TPS-Oberfläche bei Cynomolgus Affen darstellt. Jedoch sind die Behandlungsresltate nicht so ermutigend wie die Resultate einer anderen Studie mit demselben experimentellen Aufbau, bei der autologe Knochenpartikel mit Membranen bedeckt wurden. Resumen El propósito del presente estudio fue evaluar el efecto de mineral derivado bovino anorgánico poroso (Bio-Oss®) y membrana de politetrafluoroetileno expandido (ePTFE) en el tratamiento de periimplantitis. Se insertaron un total de 64 implantes con una superficie pulverizada con plasma de titanio (TPS) en 8 monos cynomolgus (Macaca fascicularis). Tras 3 meses de periodo de cicatrización con control de placa, se indujo una periimplantitis experimental caracterizada por una perdida ósea de 4-6 mm durante un periodo de 9-18 meses. Se llevó a cabo un tratamiento quirúrgico consistente en Bio-Oss+membrana, Bio-Oss, membrana, o un procedimiento de colgajo convencional (control). La evaluación por parámetros clínicos, radiográficos incluyendo radiografías digitales de sustracción cuantitativa, histología, y estereología demostraron tejidos periimplantarios sanos irrespectivamente del procedimiento quirúrgico aplicado. De todos modos, la cantidad de re-osteointegración y la cantidad total de hueso (Bio-Oss y hueso regenerado) fueron significativamente mayores en los defectos tratados con Bio-Oss cubiertos por membrana comparados con los otros 3 procedimientos terapéuticos. Se obtuvo un contacto hueso implante del 36 % dentro de los defectos tratados con Bio-Oss cubierto por membrana. Los valores correspondientes para los otros 3 procedimientos terapéuticos fueron del 13-23 %. Las partículas de Bio-Oss se integraron altamente en general con el hueso regenerado, pero las partículas en la parte oclusal de los defectos estaban enteramente rodeadas de tejido conectivo irrespectivamente de cobertura de membrana. El presente estudio demuestra que el tratamiento quirúrgico que incluye Bio-Oss cubierto por una membrana de ePTFE es una modalidad de tratamiento de la periimplantitis experimental alrededor de los implantes con una superficie TPS en monos cynomolgus. De todos modos, los resultados del tratamiento no son tan alentadores como los observados con partículas de hueso autógeno documentados en un estudio con el mismo diseño experimental. [source] | ||||||||||