Observation Interval (observation + interval)

Distribution by Scientific Domains


Selected Abstracts


Alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-7 (rhBMP-7/rhOP-1): radiographic observations

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2008
Knut N. Leknes
Abstract Aim: The objective of this study was to radiographically evaluate the potential of a purpose-designed titanium porous-oxide implant surface coated with recombinant human bone morphogenetic protein-7 (rhBMP-7), also known as recombinant human osteogenic protein-1 (rhOP-1), to stimulate alveolar ridge augmentation. Material and Methods: Six young-adult Hound Labrador mongrel dogs were used. Three 10 mm titanium oral implants per jaw quadrant were placed 5 mm into the alveolar ridge in the posterior mandible following surgical extraction of the pre-molar teeth and reduction of the alveolar ridge leaving 5 mm of the implants in a supra-alveolar position. The implants had been coated with rhBMP-7 at 1.5 or 3.0 mg/ml and were randomized to contralateral jaw quadrants using a split-mouth design. The mucoperiosteal flaps were advanced, adapted, and sutured to submerge the implants. Radiographic registrations were made immediately post-surgery (baseline), and at weeks 4 and 8 (end of study). Results: rhBMP-7-coated implants exhibited robust radiographic bone formation. At 8 weeks, bone formation averaged 4.4 and 4.2 mm for implants coated with rhBMP-7 at 1.5 and 3.0 mg/ml, respectively. There were no significant differences between the rhBMP-7 concentrations at any observation interval. A majority of the implant sites showed voids within the newly formed bone at week 4 that generally resolved by week 8. The newly formed bone assumed characteristics of the resident bone. Conclusions: The titanium porous-oxide implant surface serves as an effective carrier for rhBMP-7 showing a clinically significant potential to stimulate local bone formation. [source]


Modulation of clinical expression of plaque-induced gingivitis: response in aggressive periodontitis subjects

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2006
Leonardo Trombelli
Abstract Aim: The aim of this study was to characterize the gingival inflammatory response to de novo plaque accumulation in subjects treated for aggressive periodontitis (AP). The gingival inflammatory response of the AP subjects was retrospectively compared with that of periodontally healthy individuals (PH) matched for exposure to plaque and of periodontally healthy subjects previously identified as "high responders" (HR) and "low responders" (LR). Materials and Methods: 13 AP subjects and 26 matched PH subjects participated in a 21-day experimental gingivitis trial. Plaque index (PlI), Gingival index (GI), gingival crevicular fluid volume (GCF) and angulated bleeding score (AngBS) were recorded at days 0, 7, 14 and 21. Cumulative plaque exposure (CPE), i.e. PlI over time, was also calculated. Results: GCF was significantly higher in AP compared with PH group at each observation interval (p0.001). In addition, GCF was significantly higher in AP group compared with either LR or HR groups at each observation interval (p<0.001). Conclusions: These results suggest that susceptibility to gingival inflammation in response to de novo plaque accumulation may be related to susceptibility to periodontitis. [source]


Variation of dust endotoxin concentrations by location and time within homes of young children

PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 3 2010
Dennis R. Ownby
Ownby DR, Peterson EL, Williams LK, Zoratti EM, Wegienka GR, Woodcroft KJ, Joseph CLM, Johnson CC. Variation of dust endotoxin concentrations by location and time within homes of young children. Pediatr Allergy Immunol 2010: 21: 533,540. © 2010 John Wiley & Sons A/S Endotoxin may affect the development of allergic disease in childhood but little is known about endotoxin variation within homes. We sought to determine endotoxin concentration agreement within homes when five locations were each sampled twice 5 months apart. Endotoxin was measured using the recombinant Limulus factor C assay in dust samples from 585 homes of children enrolled in a prospective study and again in 335 homes 5 months later. The five locations sampled in each home were the child's bedroom floor, child's bed, mother's bedroom floor, mother's bed and living room floor. Concentrations of 4 allergens (Can f 1, Fel d 1, Der f 1 and Bla g 2) were also measured from the child's bedroom floor. In pair-wise comparisons, endotoxin concentrations in all locations within each home were significantly different from all other locations (p < 0.001) except for the child's and mother's bedroom floors (p = 0.272). Spearman correlations between endotoxin concentrations from the different locations were all statistically significant (p < 0.05) but of modest magnitude (r = 0.24,0.54). Similarly, correlations at each site over the 5 month observation interval were statistically significant but modest (r = 0.17,0.44). Pets and season of the year did not affect correlations, although correlations were lower if the floor was not carpeted. Endotoxin concentrations at all locations were minimally correlated with allergen concentrations in both negative and positive directions (r = ,0.12 to 0.12). We conclude that a single measurement of endotoxin from a home dust sample provides an imprecise estimate of dust endotoxin concentrations in other locations within the home and over a relatively short observation interval. [source]


Single-tooth replacement by immediate implant and connective tissue graft: a 1,9-year clinical evaluation

CLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2004
Andrea E. Bianchi
Abstract Objectives: The aim of the present study was to evaluate the long-lasting efficacy of a combined surgical protocol, using immediate implant and subepithelial connective tissue graft for single-tooth replacement. The advantages of this single-center, longitudinal, randomized, blind examiner research were the following: preservation of both keratinized mucosa amount and bone tissue, optimal peri-implant marginal sealing, satisfactory aesthetic results, reduction in treatment time. Materials and methods: In the time period from 1990 to 1998, 116 patients were consecutively admitted for treatment with a total of 116 solid screw ITI-implants supporting single crowns. Ninety-six patients underwent the proposed combined treatment (test group), while 20 received only single immediate implants (control group). The observation time extended from 1 up to 9 years. Results: The 9-year cumulative survival rate was 100% for both test and control groups. Comparative statistical analysis of soft and hard tissue peri-implant parameters demonstrated better results in the test group than in the control during every single 3-year analysis and especially in the last observation interval. The test group also showed very good results in terms of aesthetic parameters, which estimated the keratinized mucosa width, the alignment of crown emergence profile and the patient's satisfaction. Conclusion: Single-tooth replacement by immediate solid screw ITI implants in association with connective tissue autograft was demonstrated to be a predictable procedure. Moreover, this treatment can be considered as a sure system to reach an excellent functional and harmonious aesthetic restoration. Résumé Le but de l'étude présente a été d'évaluer l'efficacitéà long terme d'un protocole chirurgical combiné utilisant l'implant placé immédiatement et un greffon tissulaire de tissu conjonctif sous-épithélial pour le remplacement d'une dent unique. Les avantages de cette recherche randomisée longitudinale dans un seul centre et en aveugle étaient les suivants : préservation de la quantité de muqueuse kératinisée et du tissu osseux, une fermeture marginale paroïmplantaire optimale, des résultats esthétiques satisfaisants et une réduction du temps de traitement. Durant les années 1990 à 1998, 116 patients ont été admis pour le traitement de 116 implants ITI en vis pleines portant des couronnes uniques. Nonante-six patients ont recu le traitement proposé (groupe test) tandis que 20 autres n'ont reçu que des implants placés immédiatement en une étape (groupe contrôle). Le temps d'observation s'échelonnait de un à neuf ans. Le taux de survie cumulatif à neuf années était de 100% dans les deux groupes. L'analyse statistique comparative des tissus mous et durs paroïmplantaires a constaté des meilleurs résultats dans le groupe test que dans le groupe contrôle durant chaque analyse de trois ans et spécialement dans la dernière période d'observation. Le groupe test montrait également de très bons résultats esthétiques concernant la largeur de la muqueuse kératinisée, l'alignement du profil de l'émergence de la couronne et la satisfaction du patient. Le remplacement de dents uniques par des implants ITI en vis pleines placées immédiatement en association avec une greffe de tissu conjonctif est un processus prévisible. De plus, ce traitement peut être considéré comme un système sûr pouvant apporter une restauration fonctionnelle harmonieuse et esthétique. Zusammenfassung Ziele: Das Ziel dieser Studie war es, den Langzeiterfolg eines chirurgischen Protokolls zu untersuchen, das den Einzelzahnersatz mit einem Sofortimplantat in Kombination mit einem subepithelialen Bindegewebstransplantat vorsah. Die Vorteile dieser an einem Zentrum durchgeführten randomisierten, longitudinalen Blindstudie waren die folgenden: Erhaltung sowohl der gesamten keratinisierten Mukosa wie auch des Knochengewebes, der optimale perimplantäre marginale Abschluss, die befriedigenden ästhetischen Resultate und die Verkürzung der Behandlungszeit. Material und Methoden: In der Zeit von 1990 bis 1998 bekamen in der Folge 116 Patienten insgesamt 116 ITI-Vollschraubenimplantate, die mit Einzelkronen versorgt wurden. 96 Patienten wurden nach der vorgestellten kombinierten Methode behandelt (Testgruppe), währenddem die übrigen 20 Patienten einzig das Sofortimplantat erhielten (Kontrollgruppe). Die Beobachtungszeit reichte von 1 bis zu 9 Jahren. Resultate: Die kumulative Überlebensrate nach 9 Jahren betrug für Test- und Kontrollgruppe 100%. Eine statistische Vergleichsanalyse der Parameter von Weich- und Hartgeweben zeigte während jeder der dreijährigen Beobachtungsphasen (insbesondere in der letzten) in der Testgruppe bessere Resultate als in der Kontrollgruppe. Die Testgruppe zeigte auch bezüglich ästhetischen Parametern (Breite der keratinisierten Gingiva, Lokalisation der Durchtrittsstelle der Krone, Zufriedenheit des Patienten) sehr schöne Resultate. Zusammenfassung: Der Einzelzahnersatz mittels Sofortimplantation einer ITI-Vollschraube in Verbindung mit einem freien Bindegewebetransplantat erwies sich als gut beherrschbare Methode. Man kann diese Behandlung sogar als sicher für den Erhalt einer hervorragenden funktionellen, harmonischen und ästhetischen Rekonstruktion empfehlen. Resumen Objetivos: La intención del presente estudio fue evaluar la eficacia a largo plazo de un protocolo quirúrgico combinado, usando implantes inmediatos e injertos de tejido conectivo subepitelial para reemplazar dientes unitarios. Las ventajas de esta investigación unicentro, longitudinal, aleatoria, examinador ciego fueron las siguientes: preservación de tanto de la cantidad de mucosa queratinizada como del tejido óseo, sellado marginal periimplantario óptimo, resultados estéticos satisfactorios, reducción del tiempo del tratamiento. Material y métodos: En el periodo de tiempo desde 1990 a 1998, se admitieron 116 pacientes consecutivos para tratamiento con un total de 116 implantes macizos roscados ITI soportando coronas unitarias. Noventa y seis pacientes se sometieron al tratamiento propuesto (grupo de prueba), mientras 20 recibieron solo implantes inmediatos unitarios (grupo de control). El tiempo de observación se extendió de 1 9 años. Resultados: El índice acumulado de supervivencia a los 9 años fue del 100% tanto para el grupo de prueba como el de control. El análisis estadístico comparativo de los parámetros de los tejidos blandos y duros periimplantarios demostró mejores resultados en el grupo de prueba que en el de control, durante cada análisis de 3 años y especialmente en el último intervalo de observación. El grupo de prueba también mostró muy buenos resultados en términos de parámetros estéticos, que estimaron la anchura de la mucosa queratinizada, la alineación del perfil de emergencia de la corona y la satisfacción del paciente. Conclusión: La sustitución de un diente unitario por implantes macizos roscados inmediatos ITI en asociación con autoinjertos de tejido conectivo demostró ser un procedimiento predecible. Más aun, este tratamiento puede ser considerado como un sistema seguro para alcanzar una excelente restauración estética funcional y armónica. [source]


THE SHORT-TERM EFFECTS OF EXECUTIONS ON HOMICIDES: DETERRENCE, DISPLACEMENT, OR BOTH?,

CRIMINOLOGY, Issue 4 2009
KENNETH C. LAND
Does the death penalty save lives? In recent years, a new round of research has been using annual time-series panel data from the 50 U.S. states for 25 or so years from the 1970s to the late 1990s that claims to find many lives saved through reductions in subsequent homicide rates after executions. This research, in turn, has produced a round of critiques, which concludes that these findings are not robust enough to model even small changes in specifications that yield dramatically different results. A principal reason for this sensitivity of the findings is that few state-years exist (about 1 percent of all state-years) in which six or more executions have occurred. To provide a different perspective, we focus on Texas, a state that has used the death penalty with sufficient frequency to make possible relatively stable estimates of the homicide response to executions. In addition, we narrow the observation intervals for recording executions and homicides from the annual calendar year to monthly intervals. Based on time-series analyses and independent-validation tests, our best-fitting model shows that, from January 1994 through December 2005, evidence exists of modest, short-term reductions in homicides in Texas in the first and fourth months that follow an execution,about 2.5 fewer homicides total. Another model suggests, however, that in addition to homicide reductions, some displacement of homicides may be possible from one month to another in the months after an execution, which reduces the total reduction in homicides after an execution to about .5 during a 12-month period. Implications for additional research and the need for future analysis and replication are discussed. [source]


Anchorage of Titanium Implants with Different Surface Characteristics: An Experimental Study in Rabbits

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2000
Klaus Gotfredsen DDS
ABSTRACT Purpose: To compare the anchorage of titanium implants with different surface roughness and topography and to examine histologically the peri-implant bone after implant removal. Materials and Methods: Screw implants with five different surface topographies were examined: (1) turned ("machined"), (2) TiO2 -blasted with particles of grain size 10 to 53 ,m; (3) TiO2 -blasted, grain size 63 to 90 ,m; (4) TiO2 -blasted, grain size 90 to 125 ,m; (5) titanium plasma-sprayed (TPS). The surface topography was determined by the use of an optical instrument. Twelve rabbits, divided into two groups, had a total of 120 implants inserted in the tibiae. One implant from each of the five surface categories was placed within the left tibia of each rabbit. By a second operation, implants were installed in the right tibia, after 2 weeks in group A and after 3 weeks in group B. Fluorochrome labeling was performed after 1 and 3 weeks. Removal torque (RMT) tests of the implants were performed 4 weeks after the second surgery in group A and 9 weeks after the second surgery in group B. Thus, in group A, two healing groups were created, representing 4 and 6 weeks, respectively. The corresponding healing groups in group B were 9 and 12 weeks. The tibiae were removed, and each implant site was dissected, fixed, and embedded in light-curing resin. Ground sections were made, and the peri-implant bone was analyzed using fluorescence and light microscopy. Results: The turned implants had the lowest Sa and Sy values, whereas the highest scores were recorded for the TPS implants. The corresponding Sa and Sy values for the TiO2 -blasted implants were higher when a larger size of grain particles had been used for blasting. At all four observation intervals, the TPS implants had the highest and the turned implants the lowest RMT scores. The differences between the various TiO2 -blasted implants were, in general, small, but the screws with the largest Sa value had higher RMT scores at 6, 9, and 12 weeks than implants with lower Sa values. The histologic analysis of the sections representing 6, 9, and 12 weeks revealed that fractures or ruptures were present in the marginal, cortical peri-implant bone. In such sections representing the TPS and TiO2 -blasted implant categories, ruptures were frequently found in the zone between the old bone and the newly formed bone, as well as within the newly formed bone. Conclusions: The present study demonstrated that a clear relation exists between surface roughness, described in Sa values, and implant anchorage assessed by RMT measurements. The anchorage appeared to increase with the maturation of bone tissue during healing. [source]


Early Functional Loading of Brånemark Dental Implants: 5-Year Clinical Follow-up Study

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2000
Ingvar Ericsson DDS
ABSTRACT Background: Short-term clinical studies have indicated the possibility of one-stage surgery and early loading of machined titanium implants. However, long-term data comparing the outcome to the conventional two-stage technique are missing. Purpose: A clinical and radiographic study was performed to compare the outcome of oral rehabilitation of the endentulous mandible by fixed suprastructures connected to implants installed according to either (1) a one-stage surgical procedure and early loading (experimental group - EG) or (2) the original two-stage concept (reference group - RG). The EG and RG comprised 16 and 11 subjects, respectively. Materials and Methods: The following specific inclusion criterion were adopted: (1) all patients had to consider themselves to be in good general health, (2) the amount of bone had to enable the installation of five to six, at least 10-mm long fixtures (Mk II fixtures; Nobel Biocare AB, Göteborg, Sweden) between the mental foramina, and (3) the patients had to be available for the follow-up and maintenance program. A total of 88 implants were placed in the EG compared to 30 in the RG. In the EG, fixed appliances were connected to the implants within 20 days following implant installation while the fixed appliances in the RG were connected about 4 months following fixture installation. At delivery of the suprastructures, all patients were radiographically examined, an examination that was repeated at the 18- and 60-month follow-ups. Results: The analysis of the radiographs from the EG disclosed that during the observation period, between 18 and 60 months, the mean loss of bone support amounted to 0.2 mm (SD = 0.4). The corresponding value observed in the RG was 0.0 mm (SD = 0.5). During the 60-month observation period, no fixture was lost in any of the two groups examined. The implants under study as well as those in the reference material were at all observation intervals found to be clinically stable. Conclusions: This clinical study demonstrated that it is, at least based on a 5-year observation period, possible to successfully load via a permanent fixed rigid cross-arch suprastructure titanium dental implants soon after installation. However, such a treatment approach has to be strictly limited to the interforamina area of the endentulous mandible. Furthermore, the bone resorption was found to be within the same range around such implants as around implants installed and loaded according to the original two-stage protocal. [source]