Lido di Ostia, Italy
Lido di Ostia, Italy

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Salerno M.,Italian Institute of Technology | Patra N.,Italian Institute of Technology | Patra N.,University of Genoa | Thorat S.,Italian Institute of Technology | And 3 more authors.
Science of Advanced Materials | Year: 2012

We have investigated the effect of polishing with two different systems, namely Venus Supra and Enhance, on the properties of a resin composite currently in use for dental restorations, namely Venus Diamond. On both the non-polished and polished specimens, first the material surfaces have been imaged by scanning electron microscopy and atomic force microscopy, and quantitative information on the surface roughness has been extracted. Then the elastic properties of the composite have been measured in compression by instrumented indentation. The measured reduced modulus and hardness of the non-polished material were (12.7±2.0) GPa and (435±105) MPa, respectively. The polishing affected the elastic properties only in the case of Venus Supra system, which apparently decreased both modulus and hardness of ~10% and ~20%, respectively, when measured at a maximum indentation depth of ~2 μm. However, at higher indentation depth of ~5 μm this difference disappears. We tentatively assign the apparent decrease observed in the elastic properties to the material smear distributed on the surface by the polishing. © 2012 by American Scientific Publishers.

Salerno M.,Italian Institute of Technology | Giacomelli L.,Tirrenian Stomatologic Institute | Derchi G.,Tirrenian Stomatologic Institute | Patra N.,Italian Institute of Technology | And 2 more authors.
BioMedical Engineering Online | Year: 2010

Background: Surface roughness is the main factor determining bacterial adhesion, biofilm growth and plaque formation on the dental surfaces in vivo. Air-polishing of dental surfaces removes biofilm but can also damage the surface by increasing its roughness. The purpose of this study was to investigate the surface damage of different conditions of air-polishing performed in vitro on a recently introduced dental restorative composite.Methods: Abrasive powders of sodium bicarbonate and glycine, combined at different treatment times (5, 10 and 30 s) and distances (2 and 7 mm), have been tested. The resulting root mean square roughness of the surfaces has been measured by means of atomic force microscopy, and the data have been analyzed statistically to assess the significance. Additionally, a fractal analysis of the samples surfaces has been carried out.Results: The minimum surface roughening was obtained by air-polishing with glycine powder for 5 s, at either of the considered distances, which resulted in a mean roughness of ~300 nm on a 30 × 30 μm2surface area, whereas in the other cases it was in the range of 400-750 nm. Both untreated surfaces and surfaces treated with the maximum roughening conditions exhibited a fractal character, with comparable dimension in the 2.4-2.7 range, whereas this was not the case for the surfaces treated with the minimum roughening conditions.Conclusions: For the dental practitioner it is of interest to learn that use of glycine in air polishing generates the least surface roughening on the considered restorative material, and thus is expected to provide the lowest rate of bacterial biofilm growth and dental plaque formation. Furthermore, the least roughening behaviour identified has been correlated with the disappearance of the surface fractal character, which could represent an integrative method for screening the air polishing treatment efficacy. © 2010 Salerno et al; licensee BioMed Central Ltd.

Salerno M.,Italian Institute of Technology | Derchi G.,Tirrenian Stomatologic Institute | Thorat S.,Italian Institute of Technology | Thorat S.,University of Genoa | And 3 more authors.
Dental Materials | Year: 2011

Objectives: The purpose of this study was to characterize the surface morphology and the elastic properties of four dental restorative flowable composites currently on the market (Venus Diamond Flow, Vertise Flow, Filtex Supreme XT Flow, Surefil SDR Flow). Additionally, one adhesive system (Adhese One F) and one non-flowable composite (Venus Diamond) have also been characterized as the control materials. Methods: Surface morphology was studied by both scanning electron and atomic force microscopy, and the elastic modulus and the hardness measured by instrumented indentation. Grain analysis was performed on the microscopic images, and statistical analysis was carried out on the results of the nanoindentation measurements. Results: It was observed that Vertise, Filtek XT and Surefil SDR exhibit stiffness similar to the non-flowable Venus Diamond, whereas Venus Diamond Flow presents itself as the more compliant flowable composite, with Adhese showing intermediate stiffness. Grain analysis of the images confirmed the general rule that the mechanical properties improve with increasing filler loading, with the notable exception of Vertise Flow that shows modulus and hardness as high as 9.1 ± 0.6 and 0.43 ± 0.03 GPa, respectively, for an estimated loading of only ∼40% by volume. Significance: Whereas generally flowable composites are confirmed not to possess sufficiently strong mechanical properties for bulk restorations, exceptions can eventually be found upon appropriate laboratory screening, as presently seems to be the case for Vertise Flow. However, real practice in actual restorations and respective clinical evaluation are required for final assessment of the suggested results. © 2011 Academy of Dental Materials.

PubMed | Tirrenian Stomatologic Institute
Type: | Journal: The open dentistry journal | Year: 2011

Polishing may increase the surface roughness of composites, with a possible effect on bacterial growth and material properties. This preliminary in vitro study evaluates the effect of three different polishing systems (PoGo polishers, Enhance, Venus Supra) on six direct resin composites (Gradia Direct, Venus, Venus Diamond, Enamel Plus HFO, Tetric Evoceram, Filtek Supreme XT).For each composite, 12 square specimens were prepared: 9 specimens were polished, three for each different method, while three specimens were used as controls. Surface roughness was determined with AFM by measuring Root Mean Square (RMS) of average height.PoGo polisher determined a significantly rougher surface, versus controls, in 5 out of 6 composites evaluated. Some significant differences from unpolished controls were observed also for Enhance polishing. Polishing with Venus Supra did not result in any significant difference in surface roughness versus controls. No differences were observed between different polishing systems.These preliminary results suggest that Venus Supra polishing system could determine a smoother composite surface if compared to the other polishing systems tested. On this basis, we are conducting an in vivo study to evaluate bacterial colonization on some combinations of composites and polishing protocols.

PubMed | Tirrenian Stomatologic Institute
Type: Journal Article | Journal: The International journal of periodontics & restorative dentistry | Year: 2011

Air polishing increases the surface roughness of dental restorations, enhancing bacterial adhesion. This in vitro study was the first, to the authors knowledge, to evaluate the effect of sodium bicarbonate and glycine powders, at different application distances (2 and 7 mm) and times (5, 10, and 30 seconds), on the surface roughness of a nanocomposite material used in restorations. Untreated slides were used as controls. Surface roughness was measured using atomic force microscopy. Air polishing with glycine powder for 5 seconds, at both application distances, determined the lowest surface damage. Even with all the limitations of any in vitro analysis, this study further supports the safety of this method of air polishing.

PubMed | Tirrenian Stomatologic Institute
Type: Journal Article | Journal: Clinical oral implants research | Year: 2011

Elevation of the sinus floor with Straumann() BoneCeramic gave promising results in some recent clinical studies. However, no study has evaluated the long-term survival of implants after this surgical procedure. We are conducting a prospective, observational study to evaluate the long-term implant survival after this surgical procedure in clinical practice. We present here an ad-interim report of this study, including only patients with 12-month follow-up after implant placement.This prospective cohort study will last until a follow-up of 5 years will be achieved in at least 50 patients. Inclusion criteria are: age 18 years; presence of a maxillary partial unilateral or bilateral edentulism involving the premolar/molar areas; elective rehabilitation with oral implants; and physical capability to tolerate conventional surgical and restorative procedures. Patients are treated according to the two-stage technique and the preparation is filled with Straumann() BoneCeramic. Implant survival is evaluated every 3 months for the first 2 years, and then every 6 months up to 5 years.Fifteen patients are considered in this ad-interim analysis. Mean follow-up was 14.9 3.1 (range: 6-18 months). In total, three implants failed, in one single patient, 6 months after insertion. The cumulative implant survival rate was 92.5% (95% confidence interval: 83.0-100%).This ad-interim analysis suggests that the elevation of the sinus floor with Straumann() BoneCeramic may be an effective clinical option over >1-year follow-up. A longer term follow-up will allow a deeper characterization of these preliminary findings.

PubMed | Tirrenian Stomatologic Institute
Type: | Journal: The open dentistry journal | Year: 2010

Genomics and proteomics have promised to change the practice of dentistry and oral pathology, allowing the identification and the characterization of risk factors and therapeutic targets at a molecular level. However, mass-scale molecular genomics and proteomics suffer from some pitfalls: gene/protein expression are significant only if inserted in a detailed network of molecular pathways and gene/gene, gene/protein and protein/protein interactions. The proper analysis of these complex pictures requires the contribution of theoretical disciplines, like bioinformatics and data mining. In particular, data-mining of existing information could become a strong starting point to formulate new targeted hypotheses and to plan ad hoc experimentation.In this review, advantages and disadvantages of the above-mentioned disciplines and their potential in oral pathology are discussed. The leader gene approach is a new data mining algorithm, recently applied to some oral diseases and their correlation with systemic conditions. The preliminary results of the application of the leader gene approach to the correlation between periodontitis and heart ischemia at a molecular level are presented for the first time.

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