1,721,087 research outputs found
A Resin Infiltration Technique for Molar Hypomineralization Treatment: A Preliminary Study in a Pediatric Population
No full textPurpose: The purpose of this study was to evaluate resin infiltration (RI) technique's effects on the in vivo functional treatment of molar hypomineralization (MH)-affected permanent first molars (PFMs). Methods: Fifteen MH-affected PFMs were resin-infiltrated and evaluated for a three-month follow-up (FU). In vivo resin replicas were used for profilometric and scanning electron microscope (SEM) analysis of PFM surfaces; any variation of clinical aspect and dentin hypersensitivity was registered as: T0 equals baseline; T1 equals right after treatment; T2 equals oneweek follow-up; and T3, T4, and T5 equal one-, two-, and three-month FU. Results: At T0, MH-affected surfaces were rougher and more irregular than sound ones; at T1, resin-infiltrated surfaces were smoother while a progressive increase of superficial roughness was observed over time. Hypersensitivity improved at T1 and remained stable over time in severe MH cases. Conclusions: Resin infiltration seems to be a promising treatment, especially in managing severe molar hypomineralization cases for the evaluated follow-up
Development of di-methacrylate quaternary ammonium monomers with antibacterial activity
Full text linkNine antibacterial di-methacrylate monomers based on bis-quaternary ammonium salts (bis-QAMs) were synthesized and structurally characterized. The biological activity of the bis-QAMs was tested in terms of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) on different bacterial strains achieving promising results and, in most cases, a complete bactericidal effect using a bis-QAM concentration lower than 1 mg/mL. Two of the structures showed comparable and superior activity against S. mutans than the commercial monomer 12-methacryloyloxydodecyl pyridinium bromide (MDBP). All the bis-QAMs here described were able to inhibit S. mutans biofilm formation at a concentration equal to the MIC value. From the analysis of the obtained data, some correlation regarding the structure and the antibacterial activity of the bis-QAMs could be drawn: a flexible alkyl C12 spacer between the two quaternary ammonium moieties increased the monomer antibacterial effect in comparison to the aromatic ones; the equilibrium between hydrophobic and hydrophilic moieties was directly correlated to the bactericidal range of action; the increase of the steric hindrance of the ammonium side groups might be both advantageous or disadvantageous to the antibacterial efficacy depending on the whole monomer chemical structure. Even though the possible correlation between the monomer structures and their bacteriostatic or bactericidal effect is under investigation, the monomers exhibited low cytotoxicity on human dental pulp stem cells, confirming their promising potential in the dental materials' field
Nanoleakage and marginal quality of direct composite veneering system for cervical fillings.
Full text linkAim of this study was to evaluate the marginal adaptation and nanoleakage in class V bonded restorations before and after thermo- mechanical loading using Componeer Class V (CCV) compared to con- ventional composites. The null-hypothesis tested was that marginal adap- tation and nanoleakage of CCV was not significantly different compared to conventional composites before and after thermo-mechanical loading. Standardized Class V cavities (width 2.0mm, length 3.0mm, depth 1.5mm) were created in 40 human premolars and molars at the cement- enamel junction. Cavity dimensions were standardized using a digital caliper. Teeth were divided in four groups (N=10): Group 1 One- coat- Bond-Self-etching bonding agent with Synergy-D6+CCV (Coltene); Group 2 One- coat-Bond-Self-etching bonding agent Synergy-D6- flow+CCV (Coltene), Group 3 Scotchbond Universal adhesive system with Filtek-Supreme-XTE (3M ESPE); (Group 4) Scotchbond Universal adhesive system with Filtek-Supreme-XTE-flow (3M ESPE). Restorations were placed according to manufacturers’ instructions. Marginal quality was analyzed under a SEM using epoxy resin replicas before and after thermo-mechanical loading (240,000 mechanical cycles x 50N with a frequency of 1HZ and 7800 thermo-cycles between 5° and 55C° with chewing simulator CS4-Mechatronik). Data were statistically analyzed by two-way ANOVA and Tukey’s post-hoc test (α=0.05).Specimens were then processed to investigate nanoleakage expression under SEM.
The null hypothesis was partially accepted since no significant statistical differences were found in marginal adaptation with CCV compared to mar- gins obtained with conventional composite both before and after thermo- mechanical cycling (p>0.05). Conversely the nanoleakage analysis showed only significant differences between group 1 and group 4 (p<0.05).
The marginal quality of class V cavities restored with CCV was similar to conventional composite restorations, both before and after thermo- mechanical cycling. Nanoleakage expression was dependent on the restor- ative material type. Further clinical research is essential to confirm that composite shells for direct veneering can be a valid restorative procedure
Alginate bone scaffolds coated with a bioactive lactose modified chitosan for human dental pulp stem cells proliferation and differentiation
Full text linkBioactive and biodegradable porous scaffolds can hasten the healing of bone defects; moreover, patient stem cells seeded onto scaffolds can enhance the osteoinductive and osteoconductive properties of these biomaterials. In this work, porous alginate/hydroxyapatite scaffolds were functionalized with a bioactive coating of a lactose-modified chitosan (CTL). The highly interconnected porous structure of the scaffold was homogeneously coated with CTL. The scaffolds showed remarkable stability up to 60 days of aging. Human Dental Pulp Stem Cells (hDPSCs) cultured in the presence of CTL diluted in culture medium, showed a slight and negligible increase in terms of proliferation rate; on the contrary, an effect on osteogenic differentiation of the cells was observed as a significant increase in alkaline phosphatase activity. hDPSCs showed higher cell adhesion on CTL-coated scaffolds than on uncoated ones. CTL coating did not affect cell proliferation, but stimulated cell differentiation as shown by alkaline phosphatase activity analysis
EXPLOITATION OF FTIR MICROSPECTROSCOPY FOR THE STUDY OF BONE TISSUES AFFECTED BY PERI-IMPLANTITIS.
No full textCaratterizzazione reologica e rilassometrica di idrogeli a base di alginate di calcio
No full textStudio della reologias di idrogeli di alginato di calci, con la loro modellizzazione
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