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To evaluate the performance of a new catheter design based on different hydrodynamics aiming to reduce the development of biofilm, and compare it with a conventional Foley catheter (FC).The new proposed design (NPD) catheter is a modification of the FC, based on asymmetric positioning of the balloon and additional drainage holes allowing continuous urine drainage and complete voiding of the bladder. A first experiment was undertaken to assess drainage capability, and a second experiment was performed using a bioreactor with a set-up simulating the bladder and using the test catheter as a flow-through system. The biofilm formation of five bacterial species associated with catheter-associated urinary tract infection (CAUTI) was determined after 24 h of incubation using an MTT assay. Morphological evaluation was performed using scanning electron microscopy. In-vitro determination of residual fluid, and quantitative and morphological data on biofilm formation on the intravesical and intraluminal parts of the tested catheters were assessed.Residual fluid was significantly higher in the FC (5.60 ± 0.43 mL) compared with the NPD catheter (0.2 ± 0.03 mL). The NPD catheter showed significantly less biofilm formation (P0.0001) than the FC. Catheter design had a variable effect on biofilm formation depending on the bacterial strain tested. There was significantly less intraluminal biomass compared with intravesical biomass in both catheters (P0.0001). Multi-layered biofilms that covered the FC surfaces completely were seen for all tested strains, while the NPD catheter surfaces showed reduced biofilm formation.Modifications of the hydrodynamic characteristics of a catheter can significantly reduce bacterial colonization. Integrated design approaches combining chemical, mechanical and topographical elements can help to reduce the occurrence of CAUTI.

The current study aimed to compare the efficacy of two in vitro microbiological models based on open and closed systems designed to obtain secondary caries in an accelerated and reproducible way.A conventional resin-based composite (RBC - Majesty ES-2; Kuraray, Japan) and a resin-modified glass-ionomer cement (RMGIC - Ionolux; VOCO, Germany) were used to restore standardized class II cavities (n = 4/tooth, cervical margin in dentin) in 16 human molars. The ability to produce secondary caries with Streptococcus mutans biofilms was tested using either an open-cycle or closed-cycle bioreactor (n = 8 specimens/model). Specimens were scanned before and after the biofilm exposure using micro-CT (Skyscan 1176, 9 µm resolution, 80 kV, 300 mA). Image reconstruction was performed, and demineralization depths (µm) were evaluated at the restoration margins and a distance of 1.0 mm.Dentin demineralization could be observed in all specimens, and enamel demineralization in 50% of the specimens. The open system bioreactor produced lesions with significantly higher overall demineralization depths (p.001). However, demineralization depths at a 1.0 mm distance from the restoration margins showed no difference between open and closed systems or materials. In the open system, significantly lower demineralization depths were observed in proximity to RMGIC than RBC (p.001), which was not significantly different in the closed system (p = .382).Both systems produced in vitro secondary caries in an accelerated way. However, the open-cycle bioreactor system confirmed the caries-protective activity exerted by the RMGIC material in contrast to the RBC, better simulating materials' clinical behavior.The possibility of obtaining accelerated and reproducible secondary caries development in vitro is fundamental in testing the behavior of conventional and yet-to-come restorative dental materials. Such systems can provide faster outcomes regarding the performance of dental restorative materials compared to clinical studies, notwithstanding the importance of the latter.

To quantify the biological contamination of a dental operatory environment using a biological tracer.A Streptococcus mutans suspension was infused into the mouth of a phantom, and an operator performed standardized dental procedures using an air turbine, a contra-angle handpiece, or an ultrasonic scaler either with windows open or closed. The presence of the tracer was measured by placing Petri dishes with a selective medium at 18 sites on the dental unit and 38 sites in the surrounding operatory environment.The contamination was drastically reduced when windows were opened, no matter which handpiece was used. Air turbine spread significantly higher contamination compared to contra-angle and scaler. All tested instruments spread the tracer over the entire dental unit and the surrounding environment, including the walls and ceiling; however, higher contamination levels were detected on the dental unit compared to the operatory surfaces. Opening windows during dental operative procedures greatly reduced contamination levels for all handpieces and can be recommended for reducing airborne contamination levels.The significant levels of airborne contamination produced when operating dental handpieces can be significantly reduced by natural ventilation, i.e., simply opening the windows.

Evaluate the ability of current ion-releasing materials to remineralise bacteria-driven artificial caries lesions.Standardised class I cavities were obtained in 60 extracted human molars. Specimens underwent a microbiological cariogenic protocol (28 days) to generate artificial caries lesions and then were randomly divided into four restorative groups: adhesive + composite (negative control); glass ionomer cement (GIC); calcium silicate cement (MTA); and resin-modified calcium silicate cement (RMTA). Microhardness analysis (ΔKHN) was performed on 40 specimens (10/group, t = 30 days, 45 days, 60 days in artificial saliva, AS). Micro-CT scans were acquired (3/group, t = 0 days, 30 days, and 90 days in AS). Confocal microscopy was employed for interfacial ultra-morphology analysis (2/group, t = 0 days and 60 days in AS). Additional specimens were prepared and processed for scanning electron microscopy (SEM) and FTIR (n = 3/group + control) to analyse the ability of the tested materials to induce apatite formation on totally demineralised dentine discs (60 days in AS). Statistical analyses were performed with a significance level of 5%.Adhesive + composite specimens showed the lowest ΔKHN values and the presence of gaps at the interface when assessed through micro-CT even after storage in AS. Conversely, all the tested ion-releasing materials presented an increase in ΔKHN after storage (p 0.05), while MTA best reduced the demineralised artificial carious lesions gap at the interface. MTA and RMTA also showed apatite deposition on totally demineralised dentine surfaces (SEM and FTIR).All tested ion-releasing materials expressed mineral precipitation in demineralised dentine. Additionally, calcium silicate-based materials induced apatite precipitation and hardness recovery of artificial carious dentine lesions over time.Current ion-releasing materials can induce remineralisation of carious dentine. MTA shows enhanced ability of nucleation/precipitation of hydroxyapatite compared to RMTA and GIC, which may be more appropriate to recover severe mineral-depleted dentine.

Objectives Primary focused question for this systematic review (SR) was “Which is the evidence about surfaces decontamination and protection masks for SARS‐Cov‐2 in dental practice?” Secondary question was “Which is the evidence about surfaces decontamination and protection masks against airborne pathogens and directly transmitted viral pathogens causing respiratory infections?” Materials and Methods PRISMA guidelines were used. Studies on surface decontamination and protective masks for SARS‐CoV‐2 in dental practice were considered. Studies on other respiratory viruses were considered for the secondary question. Results No studies are available for SARS‐CoV‐2. Four studies on surface disinfection against respiratory viruses were included. Ethanol 70% and sodium hypochlorite 0,5% seem to be effective in reducing infectivity by > 3log TCID. Four RCTs compared different types of masks on HCW. The single studies reported no difference for laboratory‐diagnosed influenza, laboratory‐diagnosed respiratory infection, and influenza‐like illness. A meta‐analysis was not considered appropriate. Conclusions There is lack of evidence on the efficacy of surface disinfection and protective masks to reduce the spread of SARS‐CoV‐2 or other respiratory viruses in dentistry. However, the consistent use of respirator and routine surface disinfection is strongly suggested. There is urgent need of data on the efficacy of specific protection protocols for dental HCW against viral infections.

Background The use of dental handpieces produces aerosols containing microbial agents, bacteria, and viruses representing a high-risk situation for airborne cross infections. The aim of this study was to map and quantify the biological contamination of a dental operatory environment using a biological tracer. Methods Streptococcus mutans suspension was infused into the mouth of a manikin, and an operator performed standardized dental procedures using an air turbine, a contra-angle handpiece, or an ultrasonic scaler. The presence of the tracer was measured at 90 sites on the dental unit and the surrounding surfaces of the operatory environment. Results All tested instruments spread the tracer over the entire dental unit and the surrounding environment, including the walls and ceiling. The pattern and degree of contamination were related to the distance from the infection source. The maximum distance of tracer detection was 360 centimeters for air turbine, 300 cm for contra-angle handpiece, and 240 cm for ultrasonic scaler. No surface of the operative environment was free from the tracer after the use of the air turbine. Conclusions Attention should be paid to minimize or avoid the use of rotary and ultrasonic instruments when concerns for the airborne spreading of pandemic disease agents are present. Practical Implications This study supports the recommendations of dental associations to avoid treatments generating aerosols, especially during pandemic periods. Guidelines for the management of dental procedures involving aerosols, as well as methods for the modification of aerosols aimed to inactivate the infective agent, are urgently needed.

Innovative, nanotechnologies-featuring dental materials for CAD/CAM applications are becoming available. However, the interaction with the oral environment poses critical challenges to their longevity. The present study evaluated specific physical-chemical properties and antimicrobial potential of a CAD/CAM graphene-doped resin before and after accelerated aging protocols.Graphene nanofibers (GNF)-doped (50 ppm) PMMA (GPMMA) and control PMMA CAD/CAM discs were used. Specimens underwent aging procedures of their bulk (thermo- and load-cycling) and surface (24 h-immersion in absolute ethanol), then they were tested for flexural strength, ultimate tensile strength, sorption/solubility, and methyl-methacrylate elution. Surface characterization included x-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, surface roughness, microhardness, and scanning electron microscopy (SEM). Adherence of Streptococcus mutans and Candida albicans, and biofilm formation (continuous-flow bioreactor) by the same strains and an artificial oral microcosm were investigated.GNF-doping improved the physical-chemical bulk properties of the PMMA resin. Surface aging reduced microhardness and increased the roughness of both test and control materials. Surfaces displayed signs of swelling and degradation at SEM. Microbiological data of non-aged surfaces showed that GNF-doping significantly reduced biofilm formation by all tested strains despite having no impact on microbial adherence. After aging, microbial adherence was higher on GPMMA surfaces, while biofilm formation was not promoted.GNF-doping improved the material's performance and influenced its antimicrobial potential. This strategy seems a valuable option to overcome the effects of surface degradation induced by aging on the antimicrobial potential of PMMA resin.

Recent health care products are based on formulations claimed to provide enamel remineralization and dentinal tubules occlusion through calcium-phosphate bioactive nanocompounds ( ion-doped hydroxyapatite and precursor nanoparticles). This study aimed to test and characterize for the first time the structure and composition of a representative sample of remineralizing toothpastes and topical mousses available on the market. The enamel remineralization and dentinal tubules occlusion efficacy of tested formulations were investigated in vitro. Formulations were characterized in terms of water- and acid-insoluble fractions, and PXRD, FTIR, and EDS analyses were performed to determine their composition and investigate the presence of bioactive compounds and doping elements. All formulations containing Ca-P bioactive nanocompounds showed remineralizing ability, notably when hydroxyapatite and amorphous calcium phosphate compounds were doped with small amounts of CO3-, F, Mg, and Sr. Topical mousse formulations showed a higher tubules occlusion capability than toothpastes, independently from their composition. In conclusion, all tested formulations could express remineralizing potential both on enamel and dentin thanks to the presence of biomimetic Ca-P compounds. The presence of doping elements or CPP-ACP seems essential to allow such performances.

The aim of this in vitro study is to evaluate the effect of different acidic media on volumetric wear and surface roughness of CAD/CAM monolithic materials. Forty-eight rectangular specimens were prepared using different CAD/CAM monolithic materials: nanohybrid composite (Grandio Blocks, Voco), resin-based composite (Cerasmart, GC), lithium disilicate (E-Max, Ivoclar), and high-translucency zirconia (Katana STML, Kuraray Noritake). After storage in distilled water at 37 °C for two days, the specimens were tested using a chewing machine with a stainless-steel ball as an antagonist (49N loads, 250,000 cycles). Testing was performed using distilled water, Coca-Cola, and Red Bull as abrasive media. Wear and surface roughness analyses of the CAD/CAM materials were performed using a 3D profilometer and analyzed with two-way analysis of variance and post hoc pairwise comparison procedures. Worn surfaces were examined using scanning electron microscopy. Resin-based materials suffered higher volumetric wear than ceramics (p = 0.00001). Water induced significantly less volumetric wear than the other tested solutions (p = 0.0014), independent of the material tested. High-translucency zirconia showed less surface roughness than all the other materials tested. The selection of monolithic CAD/CAM materials to restore worn dentition due to erosive processes could impact restorative therapy stability over time. Resin-based materials seem to be more influenced by the acidic environment when subjected to a two-body wear test.

Background: DNA-RNA compounds have shown promising protection against cell oxidative stress. This study aimed to assess the cytotoxicity, protective, or preventive effect of different experimental formulations on oral epithelia’s oxidative stress in vitro. Methods: Reconstituted human oral epithelia (RHOE) were grown air-lifted in a continuous-flow bioreactor. Mouthwashes and gels containing DNA-RNA compounds and other bioactive molecules were tested on a model of oxidative stress generated by hydrogen peroxide treatment. Epithelia viability was evaluated using a biochemical MTT-based assay and confocal microscopy, structural and ultrastructural morphology was evaluated by light microscopy and TEM. Results: DNA-RNA showed non-cytotoxic activity and effectively protected against oxidative stress, but did not help in its prevention. Gel formulations did not express adequate activity compared to the mouthwashes. Excipients played a fundamental role in enhancing or even decreasing the bioactive molecules’ effect. Conclusion: A mouthwash formulation with hydrolyzed DNA-RNA effectively protected against oxidative stress without additional enhancement by other bioactive molecules. Active compounds, such as hyaluronic acid, β-Glucan, allantoin, bisabolol, ruscogenin, and essential oils, showed a protective effect against oxidative stress, which was not synergistic with the one of DNA-RNA. Incorporation of surfactant agents showed a reduced, yet significant, cytotoxic effect.

This ex vivo study aimed to compare the microtensile bond strength of fiber-reinforced and particulate filler composite to coronal and pulp chamber floor dentin using a self-etching adhesive system. Coronal dentin of 40 human molar teeth was exposed by cutting occlusal enamel with a low-speed saw. Teeth were then randomly divided into two groups (n = 20). The first group was left as is, while in the second group, pulp chamber floor dentin was exposed by trepanation. After placement of a self-etching adhesive system (G-aenial Bond, GC, Tokyo, Japan), groups were further divided into two sub-groups (n = 10) according to the type of composite: fiber-reinforced composite (EP, everX Posterior, GC, Tokyo, Japan) and particulate filler composite (GP, G-aenial Posterior, GC, Tokyo, Japan). Then, composite blocks were built up. Sticks (1.0 × 1.0 mm2) were obtained from each specimen by sectioning, then microtensile bond strength (μTBS) test was performed. Statistical analysis included one-way ANOVA test and Student’s t-test (p &lt, 0.05). μTBS values were 22.91 ± 14.66 and 24.44 ± 13.72 MPa on coronal dentin, 14.00 ± 5.83 and 12.10 ± 8.89 MPa on pulp chamber floor dentin for EP and GP, respectively. Coronal dentin yielded significantly higher μTBS than pulp chamber floor dentin (p &lt, 0.05), independently from the tested composites.

Background: This laboratory study was done to evaluate the efficacy of personal protective equipment (PPE) and high-volume evacuation (HVE) against the spread of human coronavirus type 229E (HCoV-229E) during a standard dental procedure. Methods: Patient and operator manikins were used to recreate a dental setting inside a custom-built class III cabinet–like chamber. The mouth of the patient manikin was inoculated with an HCoV-229E suspension, the viral load of which was similar to that of asymptomatic people infected with severe acute respiratory syndrome coronavirus 2. The dental procedure was performed with an air turbine handpiece and HVE for 10 seconds. The efficacy of surgical masks, N95 (filtering facepiece class 2) and filtering facepiece class 3 respirators, and face shields was tested via quantitative real-time polymerase chain reaction. Results: The wide surface on which the inoculum was spread caused low contamination. Over the external surfaces of masks and respirators, when a face shield was not worn, viral loads ranged from 1.2 through 1.4 log10 mean gene copies per cm2. When the shield was worn, viral loads dropped below the detection limit (< 0.317 log10 gene copies/cm2) for all PPE. On the operator's forehead, viral loads were 0.6 through 0.8 log10 gene copies/cm2. Inside the operator manikin's mouth, viral loads were under the detection limit when using any PPE, with or without the shield. HVE did not significantly change viral loads. Conclusions: All PPE combinations significantly reduced viral loads in the operator manikin's mouth to below the detection limit, but HVE did not decrease viral contamination. Practical Implications: Although caution is suggested when removing and disposing of PPE to avoid self-contamination, the combination of PPE and face shields drastically decreases the risk of transmitting human coronavirus during aerosol-generating dental procedures.

This in vitro study aimed to evaluate the influence of curing time on surface characteristics and microbiological behavior of three bulk-fill resin-based composites (RBCs). Materials were light-cured for either 10 s or 80 s, then finished using a standard clinical procedure. They were characterized by surface morphology (SEM), surface elemental composition (EDS), surface roughness (SR), and surface free energy (SFE). Microbiological behavior was assessed as S. mutans adherence (2 h) and biofilm formation (24 h) using a continuous-flow bioreactor. Statistical analysis included a two-way ANOVA and Tukey’s test (p < 0.05). Materials differed substantially as filler shape, dimension, elemental composition and resin matrix composition. Significant differences between materials were found for SR, SFE, and microbiological behavior. Such differences were less pronounced or disappeared after prolonged photocuring. The latter yielded significantly lower adherence and biofilm formation on all tested materials, similar to conventional RBCs. Improved photoinitiators and UDMA-based resin matrix composition may explain these results. No correlation between surface characteristics and microbiological behavior can explain the similar microbiological behavior of bulk-fill materials after prolonged photocuring. This different performance of bulk-fill materials compared with conventional RBCs, where surface characteristics, especially surface chemistry, influence microbiological behavior, may have important implications for secondary caries occurrence and restoration longevity.

Objective: We designed an in vitro study to evaluate the efficiency of an 0.5 vol% hydrogen peroxide-based spray in reducing Coronavirus 229E spread during a conventional dental procedure. Methods: A class III cabinet-like chamber was custom-built, using phantoms for both patient and operator. A suspension of HCoV-229E in artificial saliva having a similar viral load to SARS-CoV-2 asymptomatic patients was inoculated inside the patient’s phantom mouth. A 10 s-lasting dental procedure was performed using an aerosol-generating air-turbine, with or without high-volume evacuation (HVE). The effect of 0.5 vol% H2O2 cooling spray in reducing viral loads was tested. Viral presence on the operator phantom was assessed by Real-Time quantitative PCR on the mask’s outer surface, on the phantom’s forehead, and inside its mouth. Results: When the H2O2 cooling spray was used, as compared to the conventional spray, viral loads were significantly lower on all tested sites, falling below the detection limit. Viral loads did not significantly change in any tested site when HVE was used. Conclusion: The use of 0.5 vol% H2O2 cooling spray by dental handpieces drastically reduced the possibility of coronaviruses spread during aerosol-generating dental procedures. This strategy deserves further consideration among the preventive measures to be adopted during the SARS-CoV-2 pandemic.

The presence of a huge amount of data regarding the onset of a carious lesion in close proximity with a restoration must not make ourselves less aware about the fact that, still, a lot of information is missing about secondary caries formation. Many pieces of information are highly conflicting, such as the role that different microbial species have in the onset of the lesion, or the link between the existence—and width—of a gap between hard tissues and restoration, and the development of a secondary lesion, or, again, the clinical decisions regarding the replacement of a restoration due to secondary caries, and, if so, to what point stop excavating.

To investigate whether the addition of sodium-DNA (Na-DNA) to chlorhexidine (CHX)-containing mouthwash influenced morphology and viability of a reconstituted human oral epithelium (ROE), and protects ROE against oxidative stress.Multi-layered 0.5 cm² ROE specimens were positioned inside a continuous flow bioreactor and grown air-lifted for 24 hours. They were treated with phosphate-buffered saline (PBS) (n= 16) or 1 vol% H₂O₂ for 1 minute (n= 16). Then, they were treated for 5 (n= 8) or 30 minutes (n= 8) with the experimental mouthwash solutions containing: 0.2 wt% CHX, 0.2 wt% CHX + 0.2 wt% Na-DNA, 0.2 wt% Na-DNA, PBS. After 60 minutes washout specimens were subjected to tetrazolium-based viability assay (MTT) confocal laser-scanning microscopy (CLSM), and histological evaluation using optical microscopy and transmission electron microscopy (TEM).ROE treated with Na-DNA for 30 minutes revealed significantly higher viability than PBS, and CHX + Na-DNA showed higher viability after 30-minute treatment than after 5 minutes, suggesting a significant protective activity of Na-DNA. Moreover, the protective effect of Na-DNA on cell viability was higher after the induction of oxidative stress. After treatment with CHX, CLSM revealed cell stress, leading to cell death in the outer layer. On the contrary, specimens treated with Na-DNA showed a much lower number of dead cells compared to PBS, both in the absence or presence of oxidative stress. Histological examination showed that the protective action of Na-DNA formulations reached more in-depth into the epithelium exposed to oxidative stress, due to intercellular spaces opening in the outer epithelium layers, giving way to Na-DNA to the inner parts of the epithelium. It can be concluded that Na-DNA had a topical protective activity when applied for 30 minutes unless the epithelium barrier is damaged, allowing it to act more in-depth.Na-DNA showed a clear and protective action against cellular degeneration due to oxidative stress and, partly, to the exposure to CHX. Its addition to chlorhexidine mouthwash or gels could be clinically helpful in contrasting the detrimental activity of CHX on oral tissues, and in the preservation of cell viability, control of inflammation and wound healing.

Current evidence suggests that SARS-CoV-2, the virus that causes COVID-19, is predominantly spread from person to person. Aim of this narrative review is to explore transmission modality of SARS-CoV-2 to provide appropriate advice to stakeholders, in order to support the implementation of effective public health measures and protect healthcare workers that primary face the disease. “In vivo” and “in vitro” studies from laboratories and hospitals confirmed the presence of surface contamination and provided insight of SARS-CoV-2 detection in the air, particularly in indoor settings with poor ventilation where aerosol-generating procedures were performed. Measures for aerosol reduction, in conjunction with other effective infection control strategies, are needed to prevent the spread of SARS-CoV-2 in dental setting.

Demineralization of dental hard tissues is a well-known health issue and the primary mechanism responsible for caries and dentinal hypersensitivity. Remineralizing toothpastes are nowadays available to improve conventional oral care formulations regarding the prevention and repair of demineralization. In this paper, we analyzed the chemical-physical features of a commercial toothpaste (Biosmalto Caries Abrasion and Erosion, Curasept S.p.A., Saronno, Italy), with particular attention paid to the water-insoluble fraction which contains the remineralizing bioactive ingredients. Moreover, the efficacy of the toothpaste to induce enamel remineralization and to occlude dentinal tubules has been qualitatively and semiquantitatively tested in vitro on human dental tissues using scanning electron microscopy and X-ray microanalysis. Our results demonstrated that the water-insoluble fraction contained silica as well as chitosan and poorly crystalline biomimetic hydroxyapatite doped with carbonate, magnesium, strontium, and fluoride ions. The formulation showed excellent ability to restore demineralized enamel into its native structure by epitaxial deposition of a new crystalline phase in continuity with the native one. It was also able to occlude the dentinal tubules exposed completely by acid-etching. Overall, this study demonstrated that the tested toothpaste contained a biomimetic ionic-substituted hydroxyapatite-based active principle and that, within the in vitro conditions analyzed in this study, it was effective in dental hard tissue remineralization.

This study aimed at evaluating the efficacy of a novel silver-citrate root canal irrigation solution (BioAKT) on smear layer removal, sealer penetration after root canal instrumentation and antibacterial activity. Single-root teeth were endodontically treated, sealed with an epoxi-amine resin sealer and irrigated using: Group I: 5.25% sodium hypochlorite (NaOCl), Group II: silver-citrate solution (BioAKT), Group III: phosphate buffer solution (PBS), Group IV: 17% ethylenediaminetetraacetic acid (EDTA). Smear layer removal and silver deposition at the coronal, middle and apical portion of each canal were analyzed using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Sealer penetration into dentinal tubules at coronal, middle and apical portion was assessed through dye-assisted confocal microscopy (CSM). Both SEM and CSM micrographs were evaluated by two examiners (&kappa, = 0.86), who were blind to the irrigation regimens, scores were given according to the degree of penetration of the sealer. Data analysis included Pearson&rsquo, s x2 and Sidak&rsquo, s multiple comparisons. Dentin discs were polished and sterilized. Enterococcus faecalis biofilms were grown using a continuous-flow bioreactor under anaerobic conditions for 72 h. Specimens were irrigated with the tested solutions, and bacterial viability was assessed using a tetrazolium salt assay (MTT). Statistical analysis included one-way ANOVA and Student&rsquo, s post-hoc t-test (p &lt, 0.05). BioAKT and EDTA were the most efficient solutions both in removing the smear layer and allowing sealer penetration. However, at the apical portion BioAKT performed significantly better compared to EDTA both in smear layer removal and sealer penetration (p &lt, 0.05). BioAKT and NaOCl showed comparable antibacterial effect (p = 0.53). In conclusion, BioAKT represents a suitable smear layer removal agent, which allows for reliable sealer penetration at the apical portion of the root canal system and offers significant antibacterial properties.

Objectives: To evaluate the effects of microorganisms’ contamination inside the dispensing syringes of different types of resin-based composites (RBCs). Methods: This study encompassed two sections. First, an anonymous electronic survey was submitted via Google forms to Italian dentists to acquire information about composite handling during clinical procedures. Then, a bench test was performed on nanohybrid RBCs differing in matrix chemistry and fillers [FiltekTM Supreme XTE (3MTM); Venus Pearl (Kulzer GmbH); Admira Fusion x-tra (Voco)] to evaluate the microbial viability on their surfaces with/out photocuring. Uncured RBCs were exposed to standardized inocula of Streptococcus Mutans, Candida Albicans, Lactobacillus Rhamnosus, or mixt plaque in an in vitro model reproducing clinical restorative procedures. Half of the RBC specimens were cured after exposure. Microbial viability was assessed using an MTT-based test. Statistical analysis included three-way ANOVA and Tukey's tests (p

Objective: To compare the shear bond strength (SBS) values of orthodontic brackets luted using a resin-modified glass ionomer cement (RMGIC) on enamel surfaces etched using either an Er:YAG laser in two different working modes, or a conventional etching protocol, including phosphoric acid. Materials and methods: Sixty healthy human premolars were randomly allocated to three experimental groups (n = 20) and etched with: Group 1: Er:YAG laser in super-short pulse (SSP) mode (100 mJ, 20 Hz, 2 W) ; Group 2: Er:YAG laser in quantum square pulse mode (120 mJ, 10 Hz, 1.2 W) using a digitally controlled handpiece (“X-Runner”) ; Group 3 (control): 5.25% sodium hypochlorite pretreatment, then 37% phosphoric acid for 15 sec. Stainless steel brackets were bonded using light-curing RMGIC for orthodontic bonding. After term cycling (1800 cycles), SBS testing was performed using a universal testing machine. After debonding, both enamel and bracket surfaces were examined to determine the amount of RMGIC still present on the surfaces. Results: Group 3 surfaces gave the lowest mean SBS (10.6104 ± 2.66196 MPa), whereas Group 1 provided the highest 1 (13.1795 ± 3.37904 MPa), which was significantly different from the control (Group 3, p = 0.0226). Group 2 provided intermediate values (11.8486 ± 0.59832 MPa) nonsignificantly different from the control or from SSP (p = 0.4215 and p = 0.3082, respectively). Conclusions: Er:YAG laser treatment in SSP mode of enamel surfaces for orthodontic bonding provided higher SBS and a shear behavior of the luting material similar to the conventional acid-etching procedures, making it a viable alternative to acid etching.

Objectives The interfacial conditions occurring during light-curing procedures of resin-based composites (RBCs) influence their surface properties and therefore the biological behavior of the material. This study aimed to evaluate the influence of different surface curing conditions on in vitro biofilm formation by Streptococcus mutans and mixed oral microflora, in the presence or absence of surface salivary pre-conditioning. Methods Two nanohybrid RBCs and four interfacial curing conditions (open air, argon, nitrogen and glycerin) were evaluated. Surface roughness (SR), surface elemental composition (energy-dispersive X-ray spectrometry, EDS) and biofilm formation (S. mutans and oral microcosm) were assessed. Surfaces were observed using scanning electron microscopy (SEM). Microbiological tests were performed with and without saliva pre-conditioning of the surfaces. EDS analysis was performed before and after biofilm formation, and biofilm morphology was evaluated using confocal laser scanning microscopy (CLSM). Data were analyzed using multi-way ANOVA and Tukey post-hoc test (p Results Interfacial curing conditions significantly influenced SR depending on the tested RBC. EDS analysis showed that surface elemental composition was significantly influenced by the interfacial curing condition depending on the tested RBC. Interfacial curing conditions significantly influenced biofilm formation in both microbiological models in the absence of saliva pre-conditioning, depending on the tested RBC, whereas saliva pre-conditioning abrogated these effects. Conclusions Surface curing conditions significantly impacted biofilm formation in a material-dependent manner, which was abrogated when surfaces were pre-conditioned with saliva. Clinical significance Curing under glycerin did not improve the microbiological performances of the tested RBCs. These results, needing to be confirmed by in vivo data, have the potential to simplify operative procedures in restorative dentistry.

To investigate the micro push-out bond strength of individually formed (everStick Post) and prefabricated (GC Fiber Post) fiber-reinforced composite (FRC) posts cemented with three different types of self-adhesive composite cements.Forty-two single-rooted human teeth were decoronated, endodontically treated, and had post spaces prepared for everStick Post (n = 21) or GC Fiber Post (n = 21). The teeth were randomly divided into three subgroups (n = 7), and posts were cemented either with G-CEM LinkAce (GC), SpeedCEM (Ivoclar Vivadent) or RelyX U200 (3M Oral Care). Specimens were then perpendicularly sectioned and divided at the cementoenamel junction into two root levels: coronal or apical. A micro push-out test was performed using an 0.8-mm-wide stainless steel plunger. Bond strength was calculated in MPa by dividing the fracture load (N) by the bonded surface area (mm2). Log-transformed data was statistically analyzed using factorial ANOVA and Tukey's post-hoc test (α0.05). Fracture modes were determined employing a stereomicroscope, and differences were evaluated using a likelihood ratio test and Pearson's chi-squared test. Specimens were also observed using SEM.Bond strengths were significantly affected by both post type and root level (p0.05), but not by self-adhesive cement (p0.05). Fracture types showed a significantly higher prevalence of adhesive fractures at the apical level, with all fractures starting at the cement-dentin interface.Individually formed FRC posts demonstrated greater bond strength than their prefabricated FRC counterparts. The apical level of the luted posts yielded lower bond strengths than the coronal level. Failures were predominantly adhesive at the cement-dentin interface.

Objectives To evaluate the influence of surface treatments of different resin-based composites (RBCs) on S. mutans biofilm formation. Methods 4 RBCs (microhybrid, nanohybrid, nanofilled, bulk-filled) and 6 finishing-polishing (F/P) procedures (open-air light-curing, light-curing against Mylar strip, aluminum oxide discs, one-step rubber point, diamond bur, multi-blade carbide bur) were evaluated. Surface roughness (SR) (n = 5/group), gloss (n = 5/group), scanning electron microscopy morphological analysis (SEM), energy-dispersive X-ray spectrometry (EDS) (n = 3/group), and S. mutans biofilm formation (n = 16/group) were assessed. EDS analysis was repeated after the biofilm assay. A morphological evaluation of S. mutans biofilm was also performed using confocal laser-scanning microscopy (CLSM) (n = 2/group). The data were analyzed using Wilcoxon (SR, gloss) and two-way ANOVA with Tukey as post-hoc tests (EDS, biofilm formation). Results F/P procedures as well as RBCs significantly influenced SR and gloss. While F/P procedures did not significantly influence S. mutans biofilm formation, a significant influence of RBCs on the same parameter was found. Different RBCs showed different surface elemental composition. Both F/P procedures and S. mutans biofilm formation significantly modified this parameter. Conclusions The tested F/P procedures significantly influenced RBCs surface properties but did not significantly affect S. mutans biofilm formation. The significant influence of the different RBCs tested on S. mutans biofilm formation suggests that material characteristics and composition play a greater role than SR. Clinical significance F/P procedures of RBCs may unexpectedly play a minor role compared to that of the restoration material itself in bacterial colonization.

Introduction: Modern strategies for dental remineralization and prevention of dentin hypersensitivity are increasingly based on biomimetic materials. The aim of this study was to assess the clinical efficacy of a calcium-phosphate nanoparticles-based dentin desensitizer (DD, Teethmate Desensitizer, Kuraray Noritake, Japan). Methodology: 25 patients, requesting treatment after reporting sensitivity of non-carious cervical lesions and dental abrasions were recruited. Inclusion criteria were: response score ≥6 on a 10 cm-long visual analog scale (VAS) for 1+ teeth in each of two quadrants. Exclusion criteria were: presence of systemic diseases, ongoing analgesic therapy, pregnancy, presence of carious or pulpal lesions, poorly contoured restorations, enamel cracks, active periodontitis and ongoing use of desensitizing agents. The response was determined to 2 s air blast. VAS scores were collected at t=0 (PRE), immediately after treatment with the DD (POST), after 1 week, and after 1, 3 and 6 months. Half of the sites in each patient (split-mouth) were randomly treated with a placebo, and scores collected until after 1 week. The DD was then applied to the placebo sites. Results: Both DD and placebo significantly decreased VAS scores on POST confronted to PRE (p

To elucidate the impact of surface properties and the release of fluoride from different glass ionomer cements on biofilm formation.Standardized specimens manufactured from various classes of glass ionomer cements (GICs), a resin-based composite (RBC), and human enamel were subjected to surface analyses. Subsequent to simulation of salivary pellicle formation, Streptococcus mutans biofilm formation was initiated using a drip flow reactor for 48h and 96h. Biofilms were characterized by determining viable bacterial biomass and 3D biofilm architecture using SEM and CLSM; the release of fluoride from the specimens was measured using the ion selective micro method in dependence on various experimental conditions (incubation with sterile broth/bacteria/acid).Surface properties and biofilm formation correlated poorly, while the release of fluoride correlated well with viable streptococcal biomass and SEM/CLSM analyses. For all investigated materials, biofilm formation was lower than on enamel. The release of fluoride showed a significant dependency on the experimental conditions applied; the presence of biofilms reduced fluoride release in comparison to sterile incubation conditions.Within the limitations of a laboratory study, the results suggest that biofilm formation on GICs cannot be easily predicted as a function of substratum surface parameters. The release of fluoride from glass ionomer cements contributes to control biofilm formation particularly in its early phases.Glass ionomer cements can actively control microbial biofilm formation, while biofilms modulate the release of fluoride from GIC materials.

Objectives To investigate the influence of recharging dental restorative materials with fluoride on biofilm formation. Methods Specimens produced from a high-viscosity glass ionomer cement (HVGIC), a resin-modified glass ionomer cement (RMGIC), and a resin-based composite (RBC) were randomly allotted to incubation in artificial saliva either for one week (AS-1), for five weeks (AS-5), for five weeks including twice/day brushing with 1450 ppm NaF toothpaste (AS-5-brush), or one-time exposition to 5000 ppm NaF after five weeks of incubation (AS-5-exp). Human enamel was used as reference. Surface roughness and the release of fluoride from the specimens was determined; biofilm formation was simulated using mono- or multispecies microbiological models and analysed employing an MTT-based approach and confocal laser-scanning microscopy. Results Monospecies biofilm formation was significantly reduced on HVGIC in comparison to RMGIC and RBC. It was also reduced on HVGIC and enamel after treatment with fluoride in groups AS-5-brush and AS-5-exp in comparison to AS-5. These effects were particularly pronounced after 24 h, and less pronounced after 48 h of biofilm formation. In the multispecies microbiological model, similar observations were identified for HVGIC, while for enamel a significant reduction in biofilm formation was observed in groups AS-5-brush and AS-5-exp. No significant effect of fluoride treatments was identified for RMGIC and RBC, regardless of the microbiological model applied. Significance These data indicate that biofilm formation on the surfaces of a glass ionomer cement and enamel can be relevantly influenced by treatment with fluoride. Enamel may serve as a fluoride reservoir which requires regular recharge.

Objectives This study aimed to morphologically investigate the distribution of the adhesive layer when placed prior, or subsequent, to matrix positioning in direct-bonded Class II RBC restorations. Additional aim was to evaluate possible differences when using two-steps (CSE, Clearfil SE Bond2) or one-step adhesive system (CU, Clearfil Universal Bond Quick). Methods Standardized mesio-occlusal and disto-occlusal cavities were prepared on 20 human molars. Teeth were randomly allocated to two protocols according to the positioning of contoured sectional metal matrices before (M->A, n = 10), or after adhesive application (A->M, n = 10). Both adhesive systems were additioned with crystal violet dye (CV, 10 vol%). Specimen sections were evaluated using optical and scanning electron microscopy (SEM). Dynamic viscosity, pH, microshear bond strength test (μ-SBS) on enamel and dentin, and three-point bend test (3PB) of polymerized adhesive rods, were performed on both pristine and CV-additioned adhesives. Results M->A produced a layer of adhesive both on tooth-restoration interface and on external restoration surfaces in contact with the matrix. A->M produced a thin layer of adhesive on external tooth surfaces, well beyond cavity and RBC restoration margins. In all restorations, excess RBC material with uneven margins was observed protruding over the cervical margin. CV addition slightly increased pH and decreased viscosity. μ-SBS: CU + CV showed a 10-fold reduction in adhesion forces on dentine. 3PB: CSE yielded higher flexural strength values than CU. CV addition reduced flexural strength of CSE. Conclusions Both M > A and A > M generated adhesive placement disadvantages with adhesive materials being expressed in difficult to reach locations that may jeopardize complete adhesive polymerization. Clinical Significance All cervical margins of RBC restorations should be carefully finished to improve longevity, no matter the clinical protocol adopted. CV addition labelled the tested adhesives without compromising their performances considerably.

OBJECTIVES The COVID-19 pandemic had severe consequences on the health system, involving dental structures and professionals VI the first phase of the emergency, the delivery of dental care was limited to emergencies During the following phases the clinical activity will be extended to the treatments suspended due to the COVID-19 emergency and to therapies that cannot be postponed without risk for oral health of patients DISCUSSION The work of dental professionals takes place close to the patient's mouth, without protection, in a situation that involves aerosol generation At present, there is no procedure able to eliminate the cross-infection risk, neither for patients nor for dental staff Therefore the dentist can be claimed for negligence in the case of SARSCoV-2 infection of the patient, if this one assumes to become infected during the dental care session In this case, the clinical recommendations and good clinical practices issued by institutions or scientific societies, according to Law 24/2017 (so-called Gelli-Bianco law), are of great importance There is a discussion about the possibility that COVID-19 emergency could lead, at least in certain circumstances, to the mitigation of liability of professionals and healthcare structures This could be true both in the case of claims for compensation by a patient who complain cross-infection and by the worker who takes action against the employer There are many interpretations based on the availability of valid and evidence-based preventive measures available at the moment in which COVID-19 pandemic occurred On the other hand the same interpretations take into account the reason why such possible precautions have not been respected The possible offense could only occur if valid measures were available, and the healthcare professional did not respect them without a valid reason Talking about the responsibility towards the patient, a central role is played by the possibility by the healthcare professional to demonstrate the validity of treatment indications (in that pandemic/ epidemic phase) A careful balancing of the risks provided by the different treatment options must also be performed The information to the patient for COVID-19 has the dual purpose: to obtain the highest compliance with the preventive measures (triage, behavior in the studio etc ) and to make him aware of the risk of developing severe forms of COVID-19 SARS-CoV-2 cross-infection during work represents an increase in the biological risk typical of dental structures For this reason, actions are required about the Risk Assessment Document (DVR) and in terms of health surveillance of workers by the occupational physician Within dental structures, workers exposed to specific or general aggravated risk can be identified From this situation can emerge the work accident with consequent compensation for the SARS-CoV-2 contagion by INAIL The civil or criminal liability of the employer is based on different assumptions and requires proof of the tort or the crime CONCLUSIONS Dental work is carried out close to the patient mouth without airway protection and a significant amount of aerosol can be produced The pandemic created new profiles of professional responsibility both towards the patient and towards the worker CLINICAL SIGNIFICANCE Knowledge of the procedures for the prevention of contagion as well as of the new profiles of responsibility towards workers and patients leads the professional to a more aware and careful professional practice Govemment and scientific societies play a central role, providing indications aimed at risk prevention These must be systematically calibrated and reviewed as the pandemic scenario changes considering the medical/ legal value they have