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Background: It is clinically important to evaluate the surface reactivity in the biological environment of titanium endosseous implants and its ability to spontaneously nucleate a coating layer of calcium phosphates (CaP). Aim/Hypothesis: The aim was to study the surface properties of zirconium blasted acid etched titanium (ZirTi) implants decontaminated by cold plasma via argon blasting to remove organic contaminants. Material and methods: ZirTi surface (Premium implants and Prama implants, Sweden & Martina S.p.A., Italy) was studied on asreceived implants and after 28d-soaking in a simulated body fluid (HBSS) to test the ability of titanium surface to bind Ca and P and nucleate a layer rich in Ca and P (apatite or calcium phosphates precursors of apatite), following ISO 23317 specifications. Surface was analyzed by ESEM-EDX and micro-Raman spectrometry performed in the same zone as electron beam and laser beam collimated. Results: The surface was notably homogeneous among the different collar-body-apex screw portions. ESEM of as-received implants showed a uniform nano-texture with micro and nano-pits. EDX displayed Ti and O, small amounts of C, and traces of Al. Raman spectra displayed metallic titanium and sparse evidences of oxidized titanium at the beginning of the natural passivation process, the presence of scattered Zr residual of the zirconium blasting agent, and the absence of important wide bands at high wavenumber (organic contaminants). After 28-day soaking in HBSS, the surface was fairly different showing a mild/gentle roughness; peaks and irregularities appeared smoothed and softened. EDX displayed Ti, C, O and Ca, P, Na, Mg, Cl reflexes. Sparse apatite spherulites were detected. EDX data provided Ca/P atomic ratio in a range consistent with calcium phosphates precursors of apatite. Raman spectra showed the increase of titanium oxidation and the presence of phosphate groups. Conclusions and clinical implications: The coating of calcium phosphates can be considered clinically predictive of a favoured/faster osseointegration. Areas of titanium oxide may have additional clinical involvement in relationship to the biological activity of TiO2 and its interaction with the physiological electrolytes and biomolecules.

Aim: The aim of this prospective cohort study was to examine the crestal Marginal Bone Level (MBL) of PrimaConnex implants system (Keystone Dental, MA, USA) after 24 months from placement in a partially dentate patients. Material and Methods: Fifty-four patients (20males, 24females; mean-age 54.77 11.73), which encountered inclusion criteria, were enrolled in this study. A total of 122 implants were inserted by one operator. Sixty-two implants were placed in healed-site with a full-thickness flap surgical procedure and sixty implants were placed with a flapless procedure. Intraoral radiographs were taken using paralleling technique before surgery, at impression making and after 3, 6, 12 and 24 months. Metal-ceramic crown was cemented on the abutment of the implants after 3 months. Radiographs were blindly evaluated twice by two experienced examiners. MBL was assessed at mesial and distal levels between the implant shoulder and the first bone-to-implant contact. Periodontal-Index were also evaluated: Bleeding on Probing (BOP) and Pocket Depth (PD) Results: After 24 months, 119 implants were successfully osseointegrated and stable. Three implants were lost at 3 and 6 months after the insertion, (cumulative success rate; 97.54%). The total MBL was 0.33 0.62 mm at 3 months, 0.46 0.72 mm at 6 months, 0.70 0.86 mm at 12 months and 1.05 1.01 mm at 24 months. Figure shows MBL variation of the 2 groups. BOP and PD were stable and not different during the time and between the groups Conclusion: PrimaConnex implants showed a limited reduction of MBL, suggesting that both surgical techniques may preserve the integrity of marginal bone. MBL was within the normal range.

Endodontic therapy consists in the management of several tissues such as pulp tissue, periodontal tissue, periapical bone and dentine. These tissues are often contaminated by blood, periapical exudates and biological fluids. An ideal orthograde or retrograde filling material should be non toxic, noncarcinogenic, nongenotoxic, biocompatible with the host tissues, insoluble in tissue fluids, and dimensionally stable. Calcium-silicate MTA based cements own many of these ideal characteristics, but the long setting time, the non-easy handling and the lack of mechanical properties at early times are few drawbacks which may complicate the clinical application. The aim of this study was to investigate the chemical, physical and biological properties of calcium-silicate MTA cements in order to improve the mechanical properties and the handling keeping the biological characteristics unchanged. Chemical and physical properties such as setting time, solubility, water-uptake, ion release, sealing ability were investigated according the ISO and ADA specifications. The bioactivity (ability to produce apatite nano-sferulities) of MTA cements were evaluated using ESEM/EDX, micro-Raman and ATR/FTIR spettroscopy.

Commercial root end filling materials, namely two zinc oxide eugenol-based cements [intermediate restorative material (IRM), Superseal], a glass ionomer cement (Vitrebond) and three calcium-silicate mineral trioxide aggregate (MTA)-based cements (ProRoot MTA, MTA Angelus, and Tech Biosealer root end), were examined for their ability to: (a) release calcium (Ca(2+) ) and hydroxyl (OH(-) ) ions (biointeractivity) and (b) form apatite (Ap) and/or calcium phosphate (CaP) precursors. Materials were immersed in Hank's balanced salt solution (HBSS) for 1-28 days. Ca(2+) and OH(-) release were measured by ion selective probes, surface analysis was performed by environmental scanning electron microscopy/energy dispersive X-ray analysis, micro-Raman, and Fourier transform infrared spectroscopy. IRM and Superseal released small quantities of Ca(2+) and no OH(-) ions. Uneven sparse nonapatitic Ca-poor amorphous CaP (ACP) deposits were observed after 24 h soaking. Vitrebond did not release either Ca(2+) or OH(-) ions, but uneven nonapatitic Ca-poor CaP deposits were detected after 7 days soaking. ProRoot MTA, MTA Angelus, and Tech Biosealer root end released significant amounts of Ca(2+) and OH(-) ions throughout the experiment. After 1 day soaking, nanospherulites of CaP deposits formed by amorphous calcium/magnesium phosphate (ACP) Ap precursors were detected. A more mature ACP phase was present on ProRoot MTA and on Tech Biosealer root end at all times. In conclusion, zinc oxide and glass ionomer cements had little or no ability to release mineralizing ions: they simply act as substrates for the possible chemical bonding/adsorption of environmental ions and precipitation of nonapatitic Ca-poor ACP deposits. On the contrary, calcium-silicate cements showed a high calcium release and basifying effect and generally a pronounced formation of more mature ACP apatitic precursors correlated with their higher ion-releasing ability.

Negli anni ’90 sono stati introdotti in ambito odontoiatrico i primi cementi a base di silicati di calcio, comunemente denominati cementi MTA (Mineral Trioxide Aggregate). Tali cementi hanno dimostrato interessanti proprietà cliniche in chirurgia endodontica grazie alla possibilità di essere applicati in ambiente umido, ovvero in presenza di sangue o altri fluidi biologici, tipiche condizioni di un sito chirurgico osseo. Recenti studi hanno dimostrato la loro capacità di formare uno strato superficiale di materiale apatitico se immersi in soluzioni simulanti i fluidi biologici (simulated body fluids). È probabile che lo strato apatitico sia responsabile della buona attività osteogenica di questi cementi, ben dimostrata da studi in vitro ed in vivo. La proprietà di formare apatite permette di considerare tali materiali come cementi bioattivi. Questo studio ha confrontato la bioattività di un cemento calcio silicatico endodontico commerciale (White ProRoot MTA, Dentsply, USA) con quella di cementi calcio silicati sperimentali contenenti diverse percentuali di fluoruro di sodio. In particolare quantità rispettivamente dell’1% e del 10% di NaF sono state addizionate a un cemento sperimentale base (wTC-Bi) costituito da dicalcio e tricalcio silicato (belite e alite), tricalcio alluminato, solfato di calcio, cloruro di calcio ed ossido di bismuto. I cementi ottenuti sono stati denominati FTC-Bi ed F10TC-Bi. I cementi sono stati caratterizzati mediante spettroscopia micro-Raman ed ATR/FT-IR prima e dopo immersione per tempi diversi (5 ore-28 giorni) a 37°C, in simulated body fluid DPBS (Dulbecco’s Phosphate Buffered Saline). Le tecniche spettroscopiche hanno mostrato differenze significative tra la composizione dei cementi sperimentali e di ProRoot MTA, principalmente per quanto riguarda le componenti solfato e silicato. Dopo 5 ore di immersione in DPBS, i cementi contenenti fluoruro erano già ricoperti di un deposito di carbonatoapatite di tipo B (evidenziato dalla comparsa della banda Raman a 960 cm-1 e delle bande IR a 1460, 1410, 1025, 960, 870, 600, 560 cm-1) (Figura 1); il deposito era significativamente più spesso che nel caso dei cementi non contenenti fluoruro. Dopo 1 giorno di immersione in DPBS, è stata rivelata la presenza dello ione fluoruro nel reticolo cristallino dell’apatite (in maggior quantità in F10TC-Bi che in FTC). In tutti i cementi, il deposito è sempre andato aumentando in grado di maturazione, spessore ed omogeneità all’aumentare del tempo di immersione. Il cemento F10TC-Bi ha dimostrato una bioattività minore rispetto al cemento FTC-Bi. Tutti i cementi hanno mostrato la formazione di idrossido di calcio nei primi stadi di indurimento (banda IR a 3640 cm-1) ed un aumento significativo del pH del mezzo che resta basico fino a 28 giorni di immersione. In accordo con i dati di bioattività, il cemento F10TC-Bi ha mostrato una minor produzione di idrossido di calcio. In conclusione, lo studio dimostra che i cementi calcio silicati hanno una spiccata bioattività, che può essere ulteriormente aumentata con composti fluorurati.

Objectives: All endodontic sealers may be in contact with apical bone and must have high bioactivity and biological behaviour. The in vitro bioactive behaviour of commercial endodontic sealers for root canal therapy was investigated in real-time on wet fresh and set cements by using ESEM/EDX and micro-Raman. Methods: AH Plus (Dentsply, USA), Calcibiotic Root Canal Sealer - CRCS (Hygienic, USA), Pulp Canal Sealer - PCS and SealApex (Kerr, USA), and three calcium-silicate materials ProRoot MTA (Dentsply, USA), Tech Biosealer Endo (Isasan, Italy) and an experimental flowable MTA (University of Bologna, Italy) were tested. Cement discs were prepared according with manufacturer directions and analyzed in wet conditions by ESEM/EDX and micro-Raman immediately after their preparation (fresh) and after soaking at 37°C in simulated body fluid (HBSS) for 24h and 28d. The release of calcium-&-hydroxyl-ions in soaking water was tested at short times (3,24h and 7d) and at long times (14,28d). Results: Fresh wet samples displayed the elements of material composition. The surface of calcium-silicate cements resulted covered by apatite spherulitic deposits already after 24h and a continuous apatite coating at longer times. No apatite was detected neither on PCS nor on SealApex. CRCS showed some/rare apatite deposits since 24h and AH Plus revealed sporadic apatite deposits after 28d. Calcium-silicate materials and SealApex showed higher calcium-releasing than CRCS. AH Plus and PCS do not released calcium. Only calcium-silicate sealers released hydroxyl-ions. Conclusions: Commercial endodontic sealers resulted unable to induce formation of bone-like apatite layer and suggest a lack or modest level of bioactivity. On the contrary, ProRoot MTA and calcium-silicate cements demonstrated earlier bioactivity.

Negli anni ’90 il primo cemento endodontico a base di silicati di calcio è stato introdotto in commercio con l’acronimo MTA (Mineral Trioxide Aggregate). I cementi MTA hanno la caratteristica di indurirsi in presenza di acqua e quindi anche di sangue o altri fluidi biologici, condizioni tipiche di un sito chirurgico osseo. Tuttavia, una delle principali limitazioni dei primi cementi MTA è il loro elevato tempo di indurimento, con conseguente rischio di dissoluzione e dilavamento del cemento dal sito chirurgico. In diversi materiali ad uso odontoiatrico, ad esempio nei cementi vetro-ionomerici, è stato possibile ottenere una diminuzione del tempo di indurimento (ed un miglioramento delle proprietà meccaniche) incorporando la componente inorganica (fluoro-silico alluminato) in una matrice polimerica fotopolimerizzabile. Nella presente ricerca tale strategia è stata seguita per produrre un cemento MTA fotopolimerizzabile (lc-MTA), allo scopo di estenderne le applicazioni chirurgiche anche in siti chirurgici estremamente umidi per la presenza di sangue. A questo scopo, un cemento calcio silicatico di base (wTC-Ba) costituito da dicalcio e tricalcio silicato (belite e alite), tricalcio alluminato, solfato di calcio, cloruro di calcio e solfato di bario è stato addizionato di una componente organica liquida costituita da 2-idrossietil metacrilato (HEMA), trietilenglicole dimetacrilato (TEGDMA), canforochinone e etil-4-(dimetilammino) benzoato, che è stata successivamente fotopolimerizzata per ottenere il composito lc-MTA. Questo studio è stato mirato a valutare l’effetto della componente polimerica sulla capacità del cemento formare uno strato apatitico in ambiente fisiologico (bioattività), caratteristica che riveste una certa importanza perché probabilmente con l’attività osteoge-nica/osteoinduttiva di questa classe di cementi. I cementi lc-MTA e wTC-Ba (utilizzato come materiale di controllo privo della componente fotopolimerizzabile) sono stati caratterizzati mediante spettroscopia micro-Raman ed ATR/FT-IR prima e dopo immersione per tempi diversi (1-28 giorni) a 37°C, in DPBS (Dulbecco’s Phosphate Buffered Saline), una soluzione simulante i fluidi biologici. Le tecniche spettroscopiche hanno mostrato che il composito non è semplicemente una miscela fisica delle due componenti poiché tra di esse si instaurano delle interazioni. Dopo 1 giorno di immersione in DPBS, entrambi i cementi sono già ricoperti di un deposito di carbonatoapatite di tipo B (evidenziato dalla comparsa delle bande Raman a 1070 e 960 cm-1 ed IR a 1460, 1410, 1025, 960, 870, 600, 560 cm-1) (Figura 1). In base all’intensità relativa delle bande dell’apatite e delle componenti del cemento, si può affermare che il deposito è significativamente più spesso sul cemento composito lc-MTA e questa situazione permane fino a 28 giorni di immersione. La componente polimerica gioca quindi un ruolo fondamentale, come mostrato dagli studi di bioattività condotti sulle componenti polimeriche poli-HEMA, poli-TEGDMA e poli(HEMA-co-TEGDMA): esse sono in grado di enucleare una componente apatitica in seguito a immersione in soluzioni metastabili contenenti ioni Ca2+ e PO43- in un rapporto Ca/P di 1.67.

Objectives: bone like apatite formation on the surface of artificial materials is an essential requirement for materials to apply to living tissues such as apical bone. All endodontic sealers may be place in contact with apical bone tissue. The in vitro bioactivity and biological behaviour of commercial endodontic sealers for root canal therapy was investigated in real-time on wet fresh and set cements by using ESEM/EDX and Raman. Methods: AH Plus (DentSply, USA), CRCS (Hygienic, USA), Pulp Canal Sealer (Kerr, USA), ProRootMTA (DentSply, USA) and TechBiosealer endo (Isasan, Italy) a calcium-silicate cement were tested. Cement discs were prepared according with manufacturer directions and analyzed in wet conditions by ESEM/EDX (Zeiss EVO 50, Carl Zeiss, Germany) and micro-Raman (i) immediately after their preparation, (ii) after 24 hrs of immersion in DPBS used as simulated body fluids solution (SBF) and (iii) after 28 days at 37°C. Setting time, pH and calcium releasing were tested. Results: ESEM/EDX on fresh wet samples displayed the elements of material composition and an homogeneous flat surface with many voids. After 24 hrs and 28 days, only ProRoot MTA and calcium-silicate cements resulted covered by small spherulites deposits which resulted mainly composed by Calcium and Phosphorus. Micro-Raman demonstrated the appearance of apatite bands after 24 hours and after 28 days only on these cements. On the contrary, the other sealers did not displayed any surface deposits at any time. MicroRaman at 24 hrs and 28 days did not showed apatite bands. Conclusions: all commercial endodontic sealers resulted unable to induce formation of bone-like apatite layer and suggest a lack of bioactivity. On the contrary, ProRootMTA and TechBiosealer endo demonstrated earlier bioactivity.

Aim To evaluate the ion-release and the apatite-forming ability (i.e. bioactivity) of a novel, light-curable MTA-containing pulp capping material (TheraCal; Bisco Inc, USA) when immersed in phosphatecontaining solution. Methodology Sample disks (8 mm dia · 1.6 mm) of TheraCal, Dycal and ProRoot MTA (Dentsply, USA) and Vitrebond (3M; USA) were prepared. TheraCal and Vitrebond samples were light-cured on both surfaces for 20 s using a LED light after application of a transparent polyester strip (Directa Matrix Strips; Directa AB, Sweden). Dycal and ProRoot MTA samples were cured at 37°C, 98% relative humidity for a time 50% longer than the final setting time (ISO6876), i.e. 2 min for Dycal, 117 min for ProRoot MTA. The discs were immersed in 10 mL deionized water and calcium and hydroxyl ion release analyzed using ion-selective electrodes after 3 and 24 h and 3, 7, 14, 28 days at 37°C. For bioactivity evaluation, discs were immersed in 10 mL phosphate-containing solution DPBS (Dulbecco’s Phosphate Buffered Saline) at 37°C. The surface chemistry, morphology and formation of apatite on materials surface after 1, 7, 14, 28 days in DPBS was assessed by ESEM-EDX, micro-Raman and FT-IR techniques. Results TheraCal released the most calcium throughout the test period and alkalinized the surrounding fluid initially to pH 10–11 (3 h–3 day) and subsequently to pH 8 (7–28 day). Amorphous apatite (952 cm)1 Raman band) was detected within the first 24 h, while a more crystalline apatite (960 cm)1 Raman band) was seen at 7 days. A layer of apatite entirely covered the surface of TheraCal after 28 days. Conclusions TheraCal and ProRoot MTA demonstrated the capacity to form apatite after just 24 h in DPBS. Dycal showed limited, and Vitrebond no bioactivity. In this laboratory setting, TheraCal acted as a calcium-releasing material that induced the formation of apatite when in contact with biological fluids. It may have potential to promote new dentine formation and cell proliferation.

Sealing ability of calcium-containing endodontic sealers TechBiosealer Endo, CRCS and Sealapex in teeth with open apices Aim To evaluate the sealing ability of three commercial Ca- containing endodontic sealers in teeth with artificial wide-open apices ex vivo. Methodology Thirty human single-rooted teeth were shaped with ProTaper instruments (Dentsply Maillefer, Switzerland) and then enlarged using a no. 4 Gates Glidden drill (Dentsply Maillefer) to obtain an apical root canal diameter of size 110. The canals were irrigated between each instrument with 0.5 mL of EDTA and 1 mL of NaOCl, and finally rinsed with deionized water. A tailored device was designed (Prati periapical chamber): a special silicone (Optosil) support was prepared for each root and 0.02 mL of HBSS (Hank’s Balanced Salt Solution) was added at the bottom of the support to simulate the presence of periapical fluid. The samples were randomly divided into three groups and filled with a hydraulic hydrophilic bioactive calcium-silicate sealer (TechBiosealer Endo, Italy), a calcium- hydroxide eucalyptol-&-eugenol-containing sealer (CRCS – Calciobi- otic Root Canal Sealer; Hygenic, USA) or a non-eugenol calcium- hydroxide polymeric root-canal sealer (Sealapex; Kerr, USA). Each sealer was prepared according to the manufacturers instruction and gently compacted with endodontic pluggers sizes 3 and 4 (LM-Dental, Finland) in the apical 5 mm. No back-filling was performed in order to leave a fluid reservoir for fluid-flow testing. All the samples were stored at 37°C in 10 mL of HBSS and the sealing ability was assessed after 24 h, 7 days, 1 and 3 months using a micro-infiltration measurer (Gandolfi digital fluid flow-meter) working at 1 psi hydraulic pressure. The data were statistically analyzed by two-way ANOVA (Student-Newman-Keuls test, significant differences at P < 0.05). Results TechBiosealer Endo maintained a stable seal from 24 h to 3 months showing values significantly lower than the other groups (P < 0.05). The fluid filtration values of TechBiosealer Endo (»0.045 lL min)1) and Sealapex (»0284 lL min)1) groups were significantly lower (P < 0.05) than CRCS group (»1.765 lL min)1). Conclusions The use of the hydraulic Ca-containing sealer TechBiosealers Endo provided the most stable seal compared to the other commercial Ca-containing sealers up to 3 months. The use of hydraulic hydrophilic bioactive sealers is recommendable for treatment of teeth with open apices.

Objective: A liner must perform as a barrier and protect the dental pulpal complex. Calcium-silicate MTA materials recently used for pulp capping demonstrate the ability to form hydroxyapatite when immersed in simulated body fluid (Gandolfi et al. 2009, 2010). TheraCal is a light-curable resin formula which contains CaO mineral oxides, designed to be used as liner and pulp capping material that demonstrates good biocompatibility/absence of cytotoxicity. The aim of this study is to evaluate the ability of this material to form hydroxyapatite when immersed in a phosphate-containing solution. Method: TheraCal (Bisco Inc, USA), Control paste (without mineral oxides) (Bisco Inc, USA), ProRoot MTA (Dentsply, USA) were used. Sample discs (n=10 for each material) were prepared. The materials were placed in a PVC mold (8mm dia x 1.6mm) and light-cured on both surfaces for 20 seconds (per manufacture) using a LED light, after the application of a transparent polyester strip. The discs were de-molded, immersed in 10mL of a phosphate-containing solution (Dulbecco's Phosphate Buffered Saline, DPBS) in a sealed container and stored at 37°C. The surface chemistry, morphology and formation of apatite on samples surface after 1, 7, 14 and 28 days of immersion in DPBS was assessed by ESEM-EDX, micro-Raman and FT-IR techniques. Results: TheraCal demonstrated the capacity to form apatite on its surface after 24 hours immersion in DPBS, as did ProRoot MTA. Amorphous apatite (952 cm-1 Raman band) was detected within the first 24 hours, while a more crystalline apatite (960 cm-1 Raman band) was noticed at 7days. No deposit was detected on the Control. Conclusions: TheraCal is a calcium-releasing material able to induce the formation of apatite and represents a promising material in direct pulp-capping clinical/surgical procedures. The ability to form apatite may play a critical/positive role in new dentin formation.

To evaluate (i) the sealing ability of two sealers, mineral trioxide aggregate sealer (MTAS) and Pulp Canal Sealer (PCS), used with gutta-percha utilizing the fluid filtration method, (ii) leaching and surface characteristics in Hank's balanced salt solution (HBSS) over a period of time. METHODOLOGY: Surface characteristics in HBSS were evaluated under the scanning electron microscope after 1 and 28 days, and the leaching of both sealers were assessed by inductively coupled plasma atomic absorption spectrometry (ICP-AAS). In addition, 24 single rooted extracted teeth were root filled using warm vertical compaction with either MTAS or PCS used as sealers with gutta-percha. Four teeth were used as positive and negative controls. Sealing ability was evaluated after 1 or 28 days using the fluid filtration method. RESULTS: Mineral trioxide aggregate sealer exhibited crystalline deposits rich in calcium and phosphorus on its surface when in contact with a physiological solution. These crystalline deposits were absent in PCS and on MTAS stored at 100% humidity. The sealing ability of MTAS was similar to that of PCS. CONCLUSIONS: The novel sealer based on mineral trioxide aggregate had comparable sealing ability to a proprietary brand sealer cement. In contact with a simulated body fluid, the MTA sealer released calcium ions in solution that encouraged the deposition of calcium phosphate crystals.

Objectives: Bioactive calcium-releasing composites able to remineralize dentine surface represent attractive preventive and therapeutic materials in restorative dentistry. The hypothesis of the study was that experimental restorative/ composite materials containing tailored calcium-silicate particles are able to remineralize artificially demineralized dentine. Materials and methods: Calcium-aluminosilicate powder (wTC-Ba) consisting of tri- and dicalcium-silicate, tricalcium aluminate, calcium sulphate, barium sulphate, was mixed with an experimental resin (HTP-M) containing HEMA, TEGDMA and polyacrylic acid. Gradia Direct LoFlo (GC, Japan) and Vitrebond (3M ESPE, Germany) were tested as controls. Dentin disks (0.8mm±0.2mm thick and 5.0mm±1.0mm length) were prepared from human third molars following extraction by using a saw microtome. Dentin disks were demineralized by immersion in sterile 17% EDTA solution (Ogna, Italy) for 2h, standing in vertical position using a PVC support to demineralize both the major surfaces. FTIR analysis was performed on each demineralized dentine to confirm the occurred demineralization. Each demineralized dentin disk was placed in close contact with a cement sample and stored in 20mL of simulated body fluid (DPBS) at 37 ◦C. After 7 days of soaking, all dentine disks were separated from the cement, washed with 5mL of deionized water to remove the cement deposit, and analyzed by FTIR and ESEM/EDX. Results: The experimental composite released calcium (500ppm at 3h) and formed carbonated apatite (Ap) on its surface, and induced the in situ formation of a different carbonated apatite (Ap) on the surface of demineralized dentine. Control materials did not support apatite formation or dentine remineralization. Conclusions: The released calcium was adsorbed on the dentine surface and enhances its mineralization in simulated body fluid. The study supports the concept that a calciumsilicate filled composite is a smart material able to induce apatite formation for remineralization of caries-like dentine lesions. These properties may extend the range clinical applications of composite materials.

Objectives: sealing ability and apatite forming ability (bioactivity) of a new endodontic sealer based on calcium-fluoro-silicate hydraulic cement were tested. Methods: extracted single-rooted teeth were instrumented with ProTaper rotary instruments, irrigated with NaOCl, EDTA, and filled with single-cone gutta-percha (Hygienic,USA) in association with TECHBiosealer Endo (Isasan,Italy) (N=10) or CRCS (Hygienic,USA) (N=10). The apical leakage was measured after 24 hours, 1,4 weeks and 3 months of aging in simulated body fluid (Hanks' Balanced Salt Solution, HBSS) at 37°C by a digital fluid flow-meter (University of Bologna, Italy). The bioactivity i.e. apatite formation ability was assessed by ESEM/EDX, micro-Raman and FTIR analyses on materials as-prepared or aged for 6,24 hours and 1,4 weeks in HBSS. Results: TECHBiosealer group showed statistically lower apical microleakage than CRCS group. Statistical differences in fluid flow (p

Objectives: light-curing resin-modified calcium-silicate cements (lc-MTA) were designed to obtain a fast setting root-end cement for root-end filling. It was hypothesized that lc-MTA are bioactive materials with properties comparable with calcium-silicate Portland cements and ProRoot MTA. Methods: the material was prepared by mixing an amount of calcium-silicate cement, HEMA/TEGMA, canphoroquinone and barium sulphate. The setting time and the solubility were tested according with ISO. Two experimental cements (lc-MTA and MTA) and ProRoot MTA were tested. The lc-MTA was light-cured for 120 seconds. The samples were immersed in simulated body fluid, SBF (DMEM or DPBS). The pH of soaking medium and the Calcium releasing from the cement were tested with ion selective electrodes. The bioactivity was investigated with Raman and ESEM/EDX analyses. The SaOS-2 cell viability on cements was assessed after 3 days of culture by Alamar blue test. Results: the setting time was 2 minutes for lc-MTA, 74 for MTA and 76 for ProRoot MTA. The solubility of lc-MTA was significantly reduced. A complex network of round-shaped precipitates (as sub-micron spherulites), covering the cement surface, mainly composed Ca and P was observed by ESEM/EDX after 24 hours of SBF immersion. Raman confirmed the presence of apatite bands (960 cm-1). Both MTA showed a lower amount of sub-micron spherulites deposits covering cement surface than lc-MTA. All cements exerted no acute toxicity in the cell assay systems. Conclusion: the study demonstrated the early and improved bioactivity of light-curing resin-modified MTA cements. The lc-MTA with very short setting time and adequate mechanical properties expand the range of clinical application of conventional MTA cements. Early in vitro bioactivity makes the lc-MTA cements an attractive alternative to conventional MTA cements as root-end repair materials.

Objectives: Calcium-silicate cements based on MTA (Mineral Trioxide Aggregate) demonstrated excellent biocompatibility and a wide range of clinical applications. The hypothesis of the study was that MTA cements modified by PPG for root canal sealer have sealing ability and bioactivity properties. Methods: an experimental root canal sealer (PPG-MTA) was obtained adding barium sulphate, sodium fluoride and calcium sulphate to a tricalcium-silicate/dicalcium-silicate powder was mixed with polypropylene-glicole (PPG). Extracted single-rooted human teeth were instrumented with ProTaper NiTi rotary instruments, filled with single-cone gutta-percha technique in association with the experimental sealer or with CRCS sealer (Hygienic, USA) as control and stored in phosphate-containing solution (DPBS) 37°C. The sealing of each root was assessed at 24 hours, 1 week and 1 month by a fluid filtration device working at 1 psi pressure. Surface morphology and bioactivity of cement disks stored for 24 hours, 1 week and 1 month in DPBS were evaluated by ESEM/EDX, RAMAN and FTIR. Results: statistically lower filtration rate (i.e. better sealing ability) was demonstrated by PPG-MTA at 24 hours and 1 week examinations. ESEM showed the dense structure of experimental cement and EDX revealed high amounts of calcium and silicon on 24-hours aged samples, and Ca and P on 1-week and 1-month aged samples. Diffuse deposits of apatite spherulites were detected on aged samples of experimental cement. RAMAN and FTIR showed apatite bands on 24-hours and 1 week aged samples. CRCS did not showed any apatite bands. Conclusions: the ability of the experimental cement PPG–MTA to produce apatite as index of bioactivity was demonstrated. The study support the use of PPG–MTA as sealers in association with gutta-percha for root canal therapy.

Objectives: calcium-silicate MTA (Mineral Trioxide Aggregate) cement have been modified by adding HEMA and TEGMA resin to obtain an experimental light-curing root-end filling material. The hypothesis of the study was that light-curing resin-modified calcium-silicate cements (lc-MTA) possess bioactivity properties comparable to conventional MTA cements, such as ProRoot MTA (DentSply, USA). Methods: HEMA, TEGMA and photo-activator were added to a tricalcium-silicate/dicalcium silicate powder. Extracted single-rooted human teeth were instrumented with ProTaper rotary instruments and filled with single-cone gutta-percha technique. Apex was sectioned and a root-end cavity was created by ultrasonic instruments. Root-end fillings were made using ProRoot MTA or the experimental light-curing cement. All samples were then aged in simulated body fluid solution (DPBS) at 37°C for 24-hours and 1 month. Surface morphology and marginal adaptation of cements were evaluated by ESEM. Bioactivity was evaluated by EDX, RAMAN and FTIR analyses after 10 minutes, 24 hours and 1 month from their preparation. Results: ESEM analysis of fresh and aged samples revealed a good marginal adaptation of both cements. EDX showed Ca and Si peaks on fresh samples, and Ca and P peaks on 24-hours and 1- month aged samples. Diffuse deposits of apatite spherulites were detected on the surface of both aged cements. Apatite deposits filled the margin of the restoration and coated the root dentin surface. RAMAN and FTIR displayed calcium hydroxide bands on 24-hours samples and apatite bands on aged samples of both cements. Conclusions: the study confirmed the optimal sealing ability and the bioactivity of ProRoot MTA and lc-MTA cements. Resin-modified MTA kept the ability to form superficial apatite deposits and to improve marginal sealing ability.

Objectives: a calcium-silicate MTA (Mineral Trioxide Aggregate) cement have been modified by adding HEMA and TEGDMA resin to obtain an experimental light-curing resin-modified root-end filling material (LC-MTA). The hypothesis of the study was that the innovative LC-MTA cement possess bioactivity properties compareble to ProRoot MTA (DentSply, USA). Methods: HEMA, TEGDMA and photo-activator were added to a tricalcium-silicate/dicalcium-silicate powder. Extracted single-rooted human teeth were instrumented with ProTaper rotary instruments and filled with single-cone gutta-percha technique. Apex was sectioned and a root-end cavity was created by ultrasonic instruments. Root-end fillings were made using ProRoot MTA or the experimental light-curing cement. All samples were then aged in simulated body fluid solution DPBS (Dulbecco's Phosphate Buffered Saline) at 37°C for 24 hours and 1 month. Surface morphology and marginal adaptation of cements were evaluated by ESEM. Bioactivity was evaluated by EDX, Raman and FTIR analyses after 24 hours and 1 month of ageing. Results: ESEM analysis of aged samples revealed a good marginal adaptation of both cements. EDX showed Ca and Si peaks on fresh samples, and Ca and P peaks on 24-hours and 1-month aged samples. Diffuse deposits of apatite spherulites were detected on the surface of both aged cements. Apatite deposits filled the margin of the restoration and coated the root dentin surface. Raman and FTIR analyses displayed calcium hydroxide bands on 24-hours aged samples and apatite bands on aged samples of both cements. Conclusions: the study confirmed the optimal marginal adaptation and the bioactivity of ProRoot MTA and LC-MTA cements. Resin-modified MTA kept the ability to form superficial apatite deposits that improve marginal sealing ability.

Objectives: a new hydrophilic sealer based on calcium-fluoro-silicate cement was tested for its sealing, biocompatibility and bioactivity (apatite forming ability) properties. Methods: extracted single-rooted teeth were instrumented with ProTaper rotary instruments, irrigated with NaOCl, EDTA, and filled with single-cone gutta-percha (Hygienic,USA) in association with TECHBiosealer Endo (Isasan,Italy) (N=10) or CRCS (Hygienic,USA) (N=10), and measured for apical flow at 24 hours and 1,4 weeks aging in DPBS (Dulbecco's Phosphate Buffered Saline) at 37°C by a digital fluid flow-meter (University of Bologna,Italy). Apatite formation was evaluated by ESEM/EDX, Raman and FTIR analyses on materials as-prepared or aged for 6,24 hours and 1,4 weeks in DPBS. Osteoblast-like Saos-2 cells seeded on cement were tested for viability at 1,3,7 days. Results: statistical differences in fluid flow (p

Objectives: Calcium silicate cements (portland-derived cements and MTAs) are hydraulic cements capable of calcium release during their hydration and setting reaction when soaked in water and body fluids. They were developed as root-end filling materials but their clinical applications was extended to various situations, like perforation, pulp capping and apexification. The aim of this study was to evaluate the bioactivity (expressed by surface morphological modifications and chemical transformations) of two calcium-silicate cements soaked in Simulated Body Fluid (SBF) phosphate-containing. Materials and Methods: ProRoot MTA (Dentsply, USA) and experimental calcium-silicate cement (Retro TC, Italy) were used. The surface morphology and chemical properties of freshly prepared cements and of 14-days aged cements were investigated with micro-Raman, FTIR-ATR and ESEM/EDX. The ageing was performed by soaking the samples in 5ml of phosphate containing solution (SBF) for different times till 14 days. Samples in sealed holder were stored at 37°C. Results: ESEM/EDX analysis of freshly prepared cements showed the formation of needle-like crystals network on the surface. After 24 hours spherical precipitates (spherulites) deposited on the surface. The aggregation of these globular micro-crystals created bigger formations forming a surface coating. After 14 days of soaking the samples surface appeared irregular and porous. Raman analysis of fresh samples emphasized the typical bands of portland cement components, that corresponded to alite, belite and ettringite. After a 24 hours of soaking, Raman and FTIR analysis registered the same bands with a better-defined profile and the appearance of phosphate bands. Aged samples displayed calcium-phosphate bands (carbonate-apatite). Conclusions: this study demonstrated the bioactivity of calcium-silicate cements consisting in the ability to produce bone-like apatite when surrounded by a simulated body fluid. Calcium ions released from the cement react with phosphate ions from the solution inducing the formation of calcium phosphate deposits which stratify on the cement surface (biocoating).

Objectives: The aim of this study was to assess the in vitro ability of experimental materials, derived from Portland cement and designed as endodontic sealers and root-end filling materials, to produce apatite on their surface in presence of phosphate ions. Materials and methods: Calcium chloride, calcium sulphate and a phyllosilicate were added to a thermally treated white Portland cement to prepare the experimental cements wTC1% and wTC1%-TCP. The cements were mixed with deionized water. Cement disks were prepared and immersed in DPBS at 37°C. ATR-FTIR, micro-Raman and SEM-EDX analyses were carried out at different storage times on both superficial/outer and internal/fractured surfaces of the discs. Results: SEM-EDX of cements surface showed high peaks of Ca, the disappearance of Si and the absence of P the early stages (1-7 days) of storage. Detectable amount of P and the formation of a coating layer P-containing on surface were revealed after 14 days. After 21 and 28 days a thick coating layer high in P was present on cements surface. Higher peaks of P were always displayed by wTC1%-TCP. The ATR-FTIR and micro-Raman spectra of the samples stored for 1 day revealed the presence of a poorly crystalline calcium phosphate deposit on the surface of both cements. The deposit seems to be thicker and more homogeneous on wTC1%-TCP than on wTC1%. The samples stored in DPBS for longer times (7, 14 days) displayed the same bands with a better-defined profile. The samples stored for 21 and 28 days showed the bands typical of a more crystalline carbonate-apatite layer. The deposit resulted to be more crystalline on the wTC1%-TCP. Conclusions: The experimental cements may be considered Bio-active materials for the ability to form apatite on their surface in presence of environmental phosphate ions. These materials represent innovative materials for endodontics and bone application.

Objective: The aim of the study was to evaluate chemical-physical properties and apatite-forming ability of three premixed calcium silicate materials containing monobasic calcium phosphate (CaH4P2O8) bioceramic, tantalum pentoxide and zirconium oxide, recently marketed for endodontics (TotalFill BC-Sealer, BC-RRM-Paste, BC-RRM-Putty). Materials and methods: Microchemical and micromorphological analyses, radiopacity, initial and final setting times, calcium release and alkalising activity were tested. The nucleation of calcium phosphates (CaPs) and/or apatite after 28 days ageing was evaluated by ESEM-EDX and micro-Raman spectroscopy. Results: BC-Sealer and BC-RRM-Paste showed similar initial (23 h), prolonged final (52 h) setting times and good radiopacity (> 7 mm Al); BC-RRM-Putty showed fast initial (2 h) and final setting times (27 h) and excellent radiopacity (> 9 mm Al). All materials induced a marked alkalisation (pH 11–12) up to 28 days and showed the release of calcium ions throughout the entire test period (cumulative calcium release 641–806 ppm). After 28 days ageing, a well-distributed mineral layer was present on all samples surface; EDX demonstrated relevant calcium and phosphorous peaks. B-type carbonated apatite and calcite deposits were identified by micro-Raman spectroscopy on all the 28-day-aged samples; the deposit thickness was higher on BC-RRM-Paste and BC-RRM-Putty, in agreement with calcium release data. Conclusions: These materials met the required chemical and physical standards and released biologically relevant ions. The CaSi-CaH4P2O8 system present in the materials provided Ca and OH ions release with marked abilities to nucleate a layer of B-type carbonated apatite favoured/accelerated by the bioceramic presence. Clinical relevance: The ability to nucleate apatite may lead many clinical advantages: In orthograde endodontics, it may improve the sealing ability by the deposition of CaPs at the material-root dentine interface, and in endodontic surgery, it could promote bone and periodontal tissue regeneration. As premixed materials, their application in endodontics may result easier in several complex endodontic situations (apicoectomy, root perforation, presence of wide/wet apices).