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Cementum Formation (cementum + formation)
Selected AbstractsHistological evaluation of MTA as a root-end filling materialINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2007P. F. E. Bernabé Abstract Aim, To assess the histological response associated with grey mineral trioxide aggregate (GMTA) and zinc oxide eugenol (ZOE) as root-end filling materials in teeth where the root canals were not filled and the coronal access cavities were not restored. Methodology, Periapical lesions were developed in 24 premolar teeth in three dogs. The root canals were prepared and half of them were dried, filled and the coronal access restored (closed). The remaining teeth were not root filled and no coronal restoration was placed (open). Apical root-end resections were performed 3 mm from the apex, and root-end cavities were prepared with ultrasonic tips. These were randomly filled with either ZOE or GMTA in the same number of specimens using MAPSYSTEM device. After 180 days the animals were killed and blocks of tissues removed and processed for histological examination. Periradicular tissue reaction was evaluated, including severity of inflammation and cementum formation. Statistical analysis was performed using anova analysis and Tukey's test. Results, A significant difference was found between the levels of inflammation in the periradicular tissues of the GMTA/closed group, compared with the ZOE/open and ZOE/closed groups (P < 0.05) but not between GMTA/closed and GMTA/open groups. Cementum formation was not found over any ZOE specimens but over MTA in all specimens. No microorganisms were found in the interface between the material and the dentinal walls. Conclusions, GMTA was associated with less periapical inflammation and tissue response when used as a root-end filling material, even when no root filling or coronal restoration was present. [source] Periodontal repair in dogs: space-providing ePTFE devices increase rhBMP-2/ACS-induced bone formationJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2003Ulf M.E. Wikesjö Abstract Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) technologies have been shown to enhance alveolar bone formation significantly. Biomaterial (carrier) limitations, however, have restricted their biologic potential for indications where compressive forces may limit the volume of bone formed. The objective of this proof-of-principle study was to evaluate the potential of a space-providing, macroporous ePTFE device to define rhBMP-2-induced alveolar bone formation using a discriminating onlay defect model. Methods: Routine, critical size, 5,6 mm, supra-alveolar, periodontal defects were created around the third and fourth mandibular premolar teeth in four young adult Hound Labrador mongrel dogs. All jaw quadrants received rhBMP-2 (0.4 mg) in an absorbable collagen sponge (ACS) carrier. Contralateral jaw quadrants in subsequent animals were randomly assigned to receive additionally the dome-shaped, macroporous ePTFE device over the rhBMP-2/ACS implant or no additional treatment. The gingival flaps were advanced to cover the ePTFE device and teeth, and sutured. Animals were scheduled for euthanasia to provide for histologic observations of healing at 8 weeks postsurgery. Results: Healing was uneventful without device exposures. New bone formation averaged (±SD) 4.7±0.2 mm (98%) and 4.5±0.4 mm (94%) of the defect height, respectively, for jaw quadrants receiving rhBMP-2/ACS with the ePTFE device or rhBMP-2/ACS alone (p>0.05). In contrast, the regenerated bone area was significantly enhanced in jaw quadrants receiving rhBMP-2/ACS with the ePTFE device compared to rhBMP-2/ACS alone (9.3±2.7 versus 5.1±1.1 mm2; p<0.05). Cementum formation was similar for both treatment groups. Ankylosis compromised periodontal regeneration in all sites. Conclusions: The results suggest that the novel space-providing, macroporous ePTFE device appears suitable as a template to define rhBMP-2/ACS-induced alveolar bone formation. Zusammenfassung Hintergrund: Es wurde gezeigt, dass das rekombinante menschliche knochenmorphogenetische Protein 2 (rhBMP-2) die alveoläre Knochenbildung signifikant erhöht. Limitationen des Biomaterials (Träger) haben jedoch die biologischen Potenzen des Materials für die Indikationen, wo komprimierende Kräfte das Volumen des zu bildenden Knochen limitierten, eingeengt. Das Ziel dieser prinzipiellen geprüften Studie war die Evaluation der Platzhalterfunktion einer makroporösen e-PTFE Membran, um die von rhBMP-2 induzierten Knochenbildung unter Nutzung eines differenzierenden Onlaydefektmodells zu definieren. Methoden: Routinemäßig wurden supraalveoläre parodontale Defekte mit der kritischen Größe von 5,6 mm um die dritten und vierten Prämolaren bei 4 jungen adulten Labrodormischhunden geschaffen. Alle Quadranten erhielten rhBMP-2 (0.4 mg) in einem resorbierbaren Kollagenschwamm (ACS). Kontralaterale Quadranten bei den aufeinander folgenden Tieren wurden zufällig ausgewählt, um zusätzlich eine domförmige makroporöse e-PTFE Membran über das rhBMP-2/ACS Implantat oder keine zusätzliche Therapie zu erhalten. Die gingivalen Lappen wurden so präpariert, dass sie die e-PTFE Membran und Zähne bedeckten und vernäht. Die Tiere wurden 8 Wochen nach der Operation getötet und für histologische Untersuchungen vorbereitet. Ergebnisse: Die Heilung war komplikationslos ohne Exposition der Membran. Die neue Knochenbildung betrug durchschnittlich (±SD) 4.7±0.2 mm (98%) und 4.5±0.4 mm (94%) der Defekthöhe für die Quadranten, die rhBMP-2/ACS mit der e-PTFE Membran erhielten oder rhBMP-2/ACS allein (p>0,05). Im Kontrast dazu war das regenerierte Knochenfeld signifikant erweitert bei den Kieferquadranten, die rhBMP-2/ACS mit e-PTFE Membran erhielten im Vergleich zu denjenigen mit rhBMP-2/ACS allein (9.3±2.7 vs. 5.1±1.1 mm2; p<0.05). Die Zementbildung war in beiden Behandlungsgruppen ähnlich. Ankylosen gefährdeten die parodontalen Regeneration in allen Flächen. Schlussfolgerungen: Die Ergebnisse zeigen, dass die neue makroporöse Platzhalter e-PTFE Membran als Schablone nützlich ist, um die rhBMP-2/ACS induzierte alveoläre Knochenbildung zu betonen. Résumé Contexte: Des technologies utilisant la protéine-2 osseuse morphogénétique humaine recombinée (rhBMP-2) ont montré qu'elle permettait d'augmenter significativement la formation d'os alvéolaire. Les limites du biomatériel (vecteur), cependant, ont restreint leur potentiel biologique aux indications pour lesquels des forces compressives pourraient limiter le volume d'os en formation. L'objectif de cette étude fut d'évaluer le potentiel d'un dispositif en ePTFE macro-poreux permettant de créer un espace pour définir la formation d'os alvéolaire induit par la rhBMP-2 en utilisant un modèle discriminatoire de lésion. Méthodes: Des lésions parodontales supra-alvéolaires de taille critique, 5,6 mm, furent créées autour des troisièmes et quatrièmes prémolaires chez 4 Labrador adultes. Chaque quadrant a été traité par des éponges de collagène résorbables utilisé comme vecteur (ASC) contenant rhBMP-2 (0.4 mg). Les quadrants contralatéraux des animaux furent aléatoirement distribués pour recevoir (ou pas) en plus un dispositif macro-poreux en ePTFE, en forme de dôme sur les implants de rhBMP-2/ACS. Les lambeaux furent déplacés pour recouvrir le dispositif en ePTFE et les dents et suturés. Les animaux furent sacrifiés après 8 semaines pour fournir des observations histologiques de la cicatrisation. Résultats: La cicatrisation ne posait pas de problèmes et on ne nota pas d'exposition des dispositifs. La moyenne de la formation osseuse était de (±SD) 4.7±0.2 mm (98%) et 4.5±0.4 mm (94%) de la hauteur de la lésion, respectivement, pour les quadrants ayant été traités par la rhBMP-2/ACS avec le dispositif en ePTFE ou la rhBMP-2/ACS seule (p>0.05). A l'inverse, la surface osseuse régénérée était significativement plus importante dans les quadrants traités par la rhBMP-2/ACS et les dispositifs en ePTFE par rapport au site traités seulement par la rhBMP-2/ACS (9.3±2.7 vs. 5.1±1.1 mm2; p<0.05). La formation cémentaire était similaire pour les deux groupes de traitement. L'ankylose compromettait la régénération parodontale dans tous les sites. Conclusions: Ces résultats suggèrent que le dispositif en ePTFE macro-poreux, qui assure un espace, semble convenir comme standard pour définir la formation osseuse induite par la rhBMP-2/ACS. [source] Histological evaluation of MTA as a root-end filling materialINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2007P. F. E. Bernabé Abstract Aim, To assess the histological response associated with grey mineral trioxide aggregate (GMTA) and zinc oxide eugenol (ZOE) as root-end filling materials in teeth where the root canals were not filled and the coronal access cavities were not restored. Methodology, Periapical lesions were developed in 24 premolar teeth in three dogs. The root canals were prepared and half of them were dried, filled and the coronal access restored (closed). The remaining teeth were not root filled and no coronal restoration was placed (open). Apical root-end resections were performed 3 mm from the apex, and root-end cavities were prepared with ultrasonic tips. These were randomly filled with either ZOE or GMTA in the same number of specimens using MAPSYSTEM device. After 180 days the animals were killed and blocks of tissues removed and processed for histological examination. Periradicular tissue reaction was evaluated, including severity of inflammation and cementum formation. Statistical analysis was performed using anova analysis and Tukey's test. Results, A significant difference was found between the levels of inflammation in the periradicular tissues of the GMTA/closed group, compared with the ZOE/open and ZOE/closed groups (P < 0.05) but not between GMTA/closed and GMTA/open groups. Cementum formation was not found over any ZOE specimens but over MTA in all specimens. No microorganisms were found in the interface between the material and the dentinal walls. Conclusions, GMTA was associated with less periapical inflammation and tissue response when used as a root-end filling material, even when no root filling or coronal restoration was present. [source] Recombinant human basic fibroblast growth factor (bFGF) stimulates periodontal regeneration in class II furcation defects created in beagle dogsJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2003S. Murakami Several growth factors (or cytokines) have been recently investigated for their use as potential therapeutics for periodontal tissue regeneration. The objective of this study was to evaluate periodontal tissue regeneration, including new bone and cementum formation, following topical application of recombinant basic fibroblast growth factor (bFGF, FGF-2) to furcation class II defects. Twelve furcation class II bone defects were surgically created in six beagle dogs, then recombinant bFGF (30 µg/site) + gelatinous carrier was topically applied to the bony defects. Six weeks after application, periodontal regeneration was analyzed. In all sites where bFGF was applied, periodontal ligament formation with new cementum deposits and new bone formation was observed histomorphometrically, in amounts greater than in the control sites. Basic FGF-applied sites exhibited significant regeneration as represented by the new bone formation rate (NBR) (83.6 ± 14.3%), new trabecular bone formation rate (NTBR) (44.1 ± 9.5%), and new cementum formation rate (NCR) (97.0 ± 7.5%). In contrast, in the carrier-only sites, the NBR, NTBR, and NCR were 35.4 ± 8.9%, 16.6 ± 6.2%, and 37.2 ± 15.1%, respectively. Moreover, no instances of epithelial down growth, ankylosis, or root resorption were observed in the bFGF-applied sites examined. The present results indicate that topical application of bFGF can enhance considerable periodontal regeneration in artificially created furcation class II bone defects of beagle dogs. [source] | ||||||||||