Modeling, assessment, and design of porous cells based on schwartz primitive surface for bone scaffolds

The design of bone scafolds for tissue regeneration is a topic of great interest, which involves diferent issues related to geometry of architectures, mechanical behavior, and biological requirements, whose optimal combination determines the success of an implant. Additive manufacturing (AM) has widened the capability to produce structures with complex geometries, which should potentially satisfy the diferent requirements. These architectures can be obtained by means of refned methods and have to be assessed in terms of geometrical and mechanical properties. In this paper a triply periodic minimal surface (TPMS), the Schwarz's Primitive surface (P-surface), has been considered as scafold unit cell and conveniently parameterized in order to investigate the efect of modulation of analytical parameters on the P-cell geometry and on its properties. Several are the cell properties, which can afect the scafold performance. Due to the important biofunctional role that the surface curvature plays in mechanisms of cellular proliferation and diferentiation, in this paper, in addition to properties considering the cell geometry in its whole (such as volume fraction or pore size), new properties were proposed. Tese properties involve, particularly, the evaluation of local geometrical-diferential properties of the P-surface. Te results of this P-cell comprehensive characterization are very useful for the design of customized bone scafolds able to satisfy both biological and mechanical requirements. A numerical structural evaluation, by means of fnite element method (FEM), was performed in order to assess the stifness of solid P-cells as a function of the changes of the analytical parameters of outer surface and the thickness of cell. Finally, the relationship between stifness and porosity has been analyzed, given the relevance that this property has for bone scafolds design

Utilizzo di Mineral Trioxide Aggregate nella riparazione di perforazioni della forcazione: due casi clinici

Aims: Mineral Trioxide Aggregate (MTA), a Portland Cement-like materi- al, developed in 1993 by M. Torabine- jad, has been suggested in the treat- ment of furcal perforation. The aim of this study is to describe two case reports of teeth with furcal perforation treated with mineral trioxide aggre- gate. Clinical cases: two molars with a furcal perforation, due to decay and iatro- genic mistake, respectively, were treated with Mineral Trioxide Aggregate during the conventional retreatment. Clinical and radiological controls show the healing of periodontal tissues. Conclusions: the MTA seems to be the best material in the treatment of furcal perforation. Its excellent action may be connected with highly reduced quantity of liquid and bacterial leak- age, and this clinical condition seems to allow the healing of periodontal tissues

L'anatomia endodontica dei secondi molari superiori: ricerca ex vivo

Aim: of the present study was to deter- mine anatomic complexities which can be seen in maxillary second molars, with a specific attention to the presence of MB2 (second mesio-buccal) canals. Methodology: 50 maxillary second molars, which had been extracted for periodontal reasons, were selected for the study, following strict exclusion cri- teria. After determining the different roots, only the mesio-buccal one was examined. Location and number of canals were determined (i) after a normal access cavity, (ii) after a wider removal of dentine from the chamber floor, and (iii) after sectioning the root 4 mm be- low the cementum-enamel junction. Data were collected and analyzed. Results: MB2 canals were present in 44% of the examined teeth (20% of ca- ses showed Weine 2 configuration, while the remaining 24% showed Weine 3 configuration). It was possible to estabilish patency in MB2 canals only in 28% of cases. Conclusions: MB2 canals are often present in maxillary second molars, being individuated in nearly half cases. This possibility and the presence of an indipendent apex make the research of MB2 canals mandatory during the endodontic treatment

In vitro and ex vivo studies on the antibacterial efficacy of sodium hypochlorite and two new generation endodontic irrigants, Tetraclean® and MTAD, in comparison with sodium hypochlorite.

The aim of this work was to compare the efficacy of two endodontic iorrigants of new generation, Tetraclean and MTAD. Their antimicrobial effectiveness was assessed by in vitro and in vivo studies. Sodium hypochlorite was included as standard reference irrigant

Effetto antimicrobico di due nuovi irriganti nei confronti dell'Enterococcus faecalis: studio comparativo in vitro

Introduction: the antibacteric action of irri- gants in the endodontic therapy could be in- hibited by many factors. The most important one is the presence of bacterial strain (e.g. En- terococcus faecalis) resistant to irrigants and intracanal dressing action. Two new irrigants, based on antibiotics, Tetraclean and Bio Pure MTAD have been recently proposed to face this problem. The aim of this study is to com- pare the antibiotic action of these new irrig- ants. Methodology: according to NCCLS guide- lines the MIC of Tetraclean and MTAD against Enterococcus faecalis ATCC 29212 strain were determined, using dilutions from 1:2 to 1:2048. Results: Bio Pure MTAD killed all bacteria until a dilution of 1:256; Tetraclean has shown better results, until 1:1024. Conclusions: both Bio Pure MTAD and Tetr- aclean proved effective antibacteric action as compared to the Enterococcus faecalis strain examined. Tetraclean was better than MTAD. Other in vitro and in vivo studies should be performed to confirm these data

Valutazione comparativa in vitro di un nuovo plugger per il System B

A i m: t h e c o n t i n u o u s w a v e o f o b t u r a t i o n t e c h - nique requires adequate canal enlargement to insert the smallest Buchanan plugger (fine 50/06) to the ideal length, in order to prop- erly compact guttapercha in the root canal sys- tem. Due to the introduction of a new small- er plugger (30/04) shaping and obturation procedures are expected to be easier. The aim of the study was to evaluate in vitro how deep apically the new plugger penetrates and com- pare penetration with the “fine” plugger. Me t h o d o l o g y : t w o t e s t s w e r e c a r r i e d o u t , o n 10 extracted molars and on 5 mesial roots of lower molars, respectively. All canals were shaped up to apical diameter of 25 and .06 ta- p e r. I n t h e f i r s t t e s t , t h e n e w p l u g g e r w a s i n - serted as deep as possible. In the second test, initially two 30/04 pluggers and then two 50/06 pluggers were inserted in the mesial canals as deep as clinically required. Radi- ograms were taken of all samples by means of a millimetric grid. Pictures were scanned, and digitally analized. R e s u l t s : t h e f i r s t t e s t s h o w e d t h a t t h e me a n maximum depth reached by 30/04 pluggers is 1.35 mm shorter from the root canal radi- ographic terminus; in the second test 30/04 pluggers showed mean penetration values sig- nificantly deeper than those reached by 50/06 pluggers. C o n c l u s i o n s : t h e n e w 3 0/ 0 4 p l u g g e r – w hi c h is smaller and more flexible than the 50/06 one – can easily be inserted up to 2 mm from the root canal apex without removing large amounts of dentin

Terapia endodontica in seguito ad avulsione dentaria: revisione della letteratura.

INTRODUZIONE E SCOPO DELLO STUDIO In seguito al reimpianto di un elemento dentario avulso è facile incorrere in processi infettivi e di riassorbimento. A tal proposito critica è la condizione endodontica; la polpa necrotica può infatti facilmente infettarsi. Un’adeguata terapia endodontica si rileva quindi fondamentale per impedire o arrestare le possibili complicanze. Questo studio si pone l’obiettivo di eseguire una revisione sistematica della letteratura e di valutare quale debba essere la corretta gestione endodontica in seguito a reimpianto.MATERIALI E METODI Si esegue una ricerca della letteratura ponendo come domanda chiave quale debba essere la terapia endodontica del dente avulso e reimpiantato.Utilizzando quindi il catalogo MeSH si restringe il campo di ricerca tramite il termine booleano AND e lo si limita ai Major Topics. La stringa ottenuta viene applicata a PubMed.Gli item ricavati vengono sottoposti quindi ad una ulteriore analisi effettuata tramite valori descritti dal Center for Evidence-Based Medicine e dal Clinical Appraisal Skill Programme del National Health Service (UK).CONCLUSIONI La revisione della letteratura di tipo sistematico permette di vagliare oggettivamente la moltitudine di articoli oggi disponibili rendendo quindi più semplice il compito al clinico che quotidianamente affronta le diverse tematiche.Questo studio ha posto un quesito che è però rimasto irrisolto, in quanto la terapia endodontica dell’elemento avulso con dry-time > 1 ora permane argomento di discussione.Esiste una dicotomia tra chi sostiene la necessità di intervenire extra-oralmente e chi invece intra-oralmente. Si pone quindi la necessità di eseguire ulteriori studi clinici con rigidi protocolli

Valutazione al SEM di file endodontici dopo procedure di detersione

Il presente lavoro valuta la morfologia dei file endodontici dopo aver subito dievsre procedure di detersion

Rivascolarizzazione pulpare in seguito a reimpianto dentale: caso clinico.

INTRODUZIONE E SCOPO DELLO STUDIO In seguito ad avulsione dentaria il processo di guarigione del fascio vascolo-nervoso determina il piano terapeutico.Studi effettuati sulla reazione della polpa hanno permesso di identificare diversi processi di guarigione.Numerosi studi eseguiti hanno portato ad osservare la formazione di tessuto duro lungo le pareti dentinali circa 17 giorni dopo il reimpianto; mentre si osservano nuove fibre nervose circa un mese dopo. Studi di tipo microangiografico hanno dimostrato la presenza di nuovi vasi già a 4 giorni dal reimpianto; dopo 10 giorni sono stati rilevati vasi nel terzo apicale e dopo 30 giorni nell’intera camera pulpare. Lo scopo di questo studio è quello di presentare un caso clinico di rivascolarizzazione pulpare in seguito a reimpianto.MATERIALI E METODI Il paziente, di 8 anni, presenta entrambi gli incisivi centrali superiori avulsi in seguito ad un incidente sportivo.Giunge all’osservazione 30 minuti dopo il trauma, con gli elementi dentari conservati in soluzione fisiologica sin dai primi istanti. Entrambi gli elementi presentano apice beante e non completa formazione della radice.Seguendo le linee guida della IADT si decide di reimpiantare gli elementi e di eseguire uno splintaggio semi-flessibile.Si eseguono successivi controlli clinici e radiografici a 1-3-6 e 12 mesi.CONCLUSIONI Nei denti con incompleta formazione radicolare è possibile andare incontro a rivascolarizzazione; tuttavia i test elettrici e termici non sono affidabili in seguito a traumi dentali, in quanto possono dare falsi negativi. La valutazione clinica di un dente traumatizzato però richiede uno studio sintomatico, visivo e radiografico. Se il dente diviene necrotico o infetto si può andare incontro ad un processo di riassorbimento radicolare che può condurre alla perdita del dente in breve tempo.Una diminuzione della dimensione della camera pulpare o del canale radicolare sull’immagine radiografica è un segno affidabile della vitalità pulpare.Il caso discusso rappresenta la possibilità di rivascolarizzazione in seguito a reimpianto a breve termine

Coming down from the trees: is terrestrial activity in Bornean orangutans natural or disturbance driven?

The orangutan is the world's largest arboreal mammal, and images of the red ape moving through the tropical forest canopy symbolise its typical arboreal behaviour. Records of terrestrial behaviour are scarce and often associated with habitat disturbance. We conducted a large-scale species-level analysis of ground-based camera-trapping data to evaluate the extent to which Bornean orangutans Pongo pygmaeus come down from the trees to travel terrestrially, and whether they are indeed forced to the ground primarily by anthropogenic forest disturbances. Although the degree of forest disturbance and canopy gap size influenced terrestriality, orangutans were recorded on the ground as frequently in heavily degraded habitats as in primary forests. Furthermore, all age-sex classes were recorded on the ground (flanged males more often). This suggests that terrestrial locomotion is part of the Bornean orangutan's natural behavioural repertoire to a much greater extent than previously thought, and is only modified by habitat disturbance. The capacity of orangutans to come down from the trees may increase their ability to cope with at least smaller-scale forest fragmentation, and to cross moderately open spaces in mosaic landscapes, although the extent of this versatility remains to be investigated