Take a look at the heart: Incidental detection of a right atrial thrombus during abdominal MR.

Cardiac masses include a wide range of lesions whose nature could be both neoplastic (primary and secondary) or not. Here we report the case of a 53-year-old woman referred to our center for pancreatic lesion follow up by magnetic resonance. The collateral finding of a rounded-shaped lesion in the right heart atrium, during the abdomen examination, led to further diagnostic investigation. Cardiovascular magnetic resonance by nonparametric and parametric sequences was performed to settle the differential diagnosis, allowing for the definition of right atrial thrombus. At the best of our knowledge no data are available in literature about the incidental diagnosis of cardiac thrombi through abdominal magnetic resonance. This case underlines the importance of image evaluation for incidental findings, further demonstrating the feasibility of initiating an image-guided therapy after a characterization by CMR.

Long-Term Evaluation of Pulp Vitality Preservation in Direct and Indirect Pulp Capping: A Retrospective Clinical Study.

Background: This retrospective clinical study aimed to assess dental pulp tissue reactions to direct and indirect pulp capping after 10 years of follow-up. Methods: A total of 276 permanent teeth with deep carious lesions were evaluated and divided into five groups: Group (1), direct pulp capping with Mineral Trioxide Aggregate cement; Group (2), direct pulp capping with a resin-based glass ionomer; Group (3), direct pulp capping with TheraCal; Group (4), indirect pulp capping with a three-step total-etch adhesive system; and Group (5), indirect pulp capping with a two-step self-etch adhesive system. Results: A 72.5% success rate was achieved overall. A statistically significant difference was found when comparing direct and indirect pulp capping with a success rate of 23.8% and 93.8%, respectively. For direct pulp-capping procedures, the area of pulp exposure was correlated with pulp necrosis (p = 0.035), while bleeding after exposure appeared independent (p = 0.053). Patient age was significantly related to the maintenance of pulp vitality (p = 0.013). A statistically significant correlation between the pulp-capping material and the occurrence of pulp necrosis was discovered (p = 0.017). For the indirect pulp-capping treatments, a significant correlation between patient age (p = 0.021) and the adhesive system (p = 0.019) with pulp necrosis was described. Conclusions: The pulp-capping material, patient age, and the width of the pulp exposure before the procedure should be carefully considered when performing direct pulp-capping treatments. The performance of the etch-and-rinse adhesive systems was superior to the self-etch system during the indirect pulp-capping procedures.

Confocal laser scanning evaluation of the influence of ledges on root canal disinfection.

The aim was to analyse the influence of an apical ledge on root canal disinfection. Forty-four single-rooted teeth were micro-CT scanned and inoculated with Enterococcus faecalis. In Group S shaping was performed with ProTaper Next (PTN) up to X3 at working length (WL). In Group L an apical ledge was created with K-Files #40 and shaping completed up to PTN X3. NaOCl 5% and EDTA 10% irrigant solutions were alternated. Confocal laser scanning microscope (CLSM) and viability staining were used to analyse the proportions of dead (red) and live (green) bacteria and penetration ability inside dentinal tubules. Data were analysed with the Mann-Whitney test with Bonferroni correction (p < 0.05). In Group L the amount of red fluorescence resulted significantly lower, and penetration ability was decreased in the apical and middle portion (p < 0.05). The presence of an apical ledge may negatively influence the disinfection both in the apical and middle third.

Endodontic Treatment of Chronic Apical Periodontitis Ameliorates Systemic Inflammation and Restores Impaired Cellular Responses to Insulin in an In Vitro Model.

INTRODUCTION: A growing body of research supports an association between periapical inflammation and an increased risk of developing systemic diseases. There is currently no scientific evidence to support a causal effect of inflammation on the onset of insulin resistance (IR) in patients with apical periodontitis (AP). The aim of this in vitro study was to evaluate any association between AP and levels of serum inflammatory factors potentially associated with the onset of IR, and to investigate the effect of root canal treatment (RCT) on these systemic inflammation markers and on the response in vitro to insulin. METHODS: A total of 27 control subjects and 27 patients with AP were enrolled. Patients with AP underwent RCT and were followed-up 6 and 12 months post-treatment. Enzyme-linked immunosorbent assays were used to evaluate serum levels of proinflammatory cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-α. The response in vitro to insulin was assessed by measuring glucose consumption in a human pancreatic epithelioid carcinoma cell line treated with sera from healthy and AP subjects. RESULTS: At baseline AP was associated with significant higher levels of IL-1, IL-6, and IL-8 in the serum of untreated (AP) patients vs controls (P < .001). Glucose consumption decreased in pancreatic cells incubated with baseline serum from patients with AP, in a manner proportional to total cytokines amount. Notably, endodontic treatment was associated with reduced levels of cytokines (P < .001) and improved response to insulin in AP group (P < .001). CONCLUSIONS: Our findings suggest that AP may promote inflammatory-driven IR in an in vitro model, and that RCT may ameliorate inflammatory mediators in vivo and the cellular response to insulin in vitro.

Are periodontitis and psoriasis associated? A pre-clinical murine model.

AIM: To investigate the bidirectional influence between periodontitis and psoriasis, using the respective experimental models of ligature- and imiquimod-induced diseases on murine models. MATERIALS AND METHODS: Thirty-two C57/BL6J mice were randomly allocated to four experimental groups: control (P- Pso-), ligature-induced periodontitis (P+ Pso-), imiquimod-induced psoriasis (P- Pso+) and periodontitis and psoriasis (P+ Pso+). Samples (maxilla, dorsal skin and blood) were harvested immediately after death. Measures of periodontitis (distance between the cemento-enamel junction and alveolar bone crest [CEJ-ABC] and the number of osteoclasts) and psoriasis (epidermal thickness and infiltrate cell [/0.03mm2]) severity as well as systemic inflammation (IL-6, IL-17A, TNF-α) were collected. RESULTS: The P+ Pso+ group exhibited the most severe experimental periodontitis and psoriasis, with the highest values of CEJ-ABC, number of osteoclasts, epidermal thickness and infiltrate cells in the dorsal skin, as well as the highest blood cytokine concentration. The P+ Pso- group presented with higher cell infiltrate (/0.03mm2) compared to the control group (p <.05), while the P- Pso+ group showed substantially higher alveolar bone loss (CEJ-ABC) than the control group (p <.05). CONCLUSIONS: Experimental periodontitis may initiate and maintain psoriasiform skin inflammation and, vice versa, experimental psoriasis may contribute to the onset of periodontitis. In a combined model of the diseases, we propose a bidirectional association between periodontitis and psoriasis via systemic inflammation.

Effects of Etching Time and Ethanol Wet Bonding on Bond Strength and Metalloproteinase Activity in Radicular Dentin.

(1) Background: The objective of this in vitro study was to evaluate the impact of different etching times and ethanol pre-treatments on the immediate bond strength of a hydrophilic multi-mode universal adhesive (Clearfil Universal Bond Quick, Kuraray, UBQ) and on the consequent gelatinolytic activity of metalloproteinases (MMPs) on radicular dentin. (2) Methods: Sixty single-root teeth were selected and divided into four groups according to the adhesive protocol applied for fiber post cementation: (G1) 15 s H3PO4 application + UBQ; (G2) 30 s H3PO4 application + UBQ; (G3) 15 s H3PO4 application + ethanol pre-treatment + UBQ; (G4) 30 s H3PO4 + ethanol pre-treatment + UBQ. After adhesive procedures, fiber posts were luted into the post space with a dual-curing cement (DC Core, Kuraray) and light-cured for 40 s. To perform the push-out test and nanoleakage analyses for both coronal end apical areas, 1 mm slices were prepared, following a 24 h storage period in artificial saliva. Additionally, an in situ zymographic assay was conducted to explore endogenous MMP activity within the radicular layer. Results were statistically analyzed with ANOVA and Tukey post hoc tests. Statistical significance was set at p < 0.05. (3) Result: ANOVA revealed a statistically significant difference in push-out bond strength related to the pre-treatment variable but did not highlight any significance of etching time. Specimens pre-treated with ethanol wet bond application showed higher bond strength (p < 0.01). In situ zymography quantification analyses revealed that all tested groups, independently of etching time end ethanol pre-treatment, activated MMP gelatinolytic activity. A significant increase in MMP activity was detected for the 30 s etching time. However, ETOH pre-treatment significantly reduced MMP activity within the adhesive interface (p < 0.01). (4) Conclusions: The tested adhesive showed similar results regardless of the etching time protocol. The gelatinolytic activity of MMPs was observed in all the groups. Further investigations and extended follow-ups are required to validate the results of the present study in vivo.

Translucency of bulk-fill composite materials: A systematic review.

OBJECTIVES: To conduct a systematic review on the translucency of bulk-fill (BF) composite materials, evaluating the factors influencing it and its clinical implications. MATERIALS AND METHODS: A systematic search was performed on four databases (Embase, Medline/PubMed, Scopus, and Web of Science) for articles published until October 2, 2023. Search terms were: "translucency," "translucency parameter," "contrast," "contrast ratio," "bulk," "bulk-fill," "bulk fill," "composite," "resin," "resin based," "resin-based," "restoration," and "dental." In vitro studies, written in English language, investigating BF resin-based composites translucency were included. The risk of bias was performed with the RoBDEMAT tool. RESULTS: Of 590 screened articles, 13 were included in this review. They investigated 11 high-viscosity BF and 5 low viscosity ones. The limited number of the identified studies and the heterogeneity of the extracted data did not allow to conduct a meta-analysis. CONCLUSIONS: BF materials exhibit variability in translucency due to variations in experimental designs and the heterogeneous composition. CLINICAL SIGNIFICANCE: BFs may behave differently in masking the substrate or in blending capacity.

How do different intraoral scanners and milling machines affect the fit and fatigue behavior of lithium disilicate and resin composite endocrowns?

The aim of this in vitro study was to evaluate the effect of the combinations of two different intraoral scanners (IOS), two milling machines, and two restorative materials on the marginal/internal fit and fatigue behavior of endocrowns produced by CAD-CAM. Eight groups (n= 10) were considered through the combination of TRIOS 3 (TR) or Primescan (PS) IOS; 4-axes (CR; CEREC MC XL) or 5-axes (PM; PrograMill PM7) milling machines; and lithium disilicate (LD; IPS e.max CAD) or resin composite (RC; Tetric CAD) restorative materials. Specific surface treatments were applied to each material, and the bonding to its corresponding Endocrown-shaped fiberglass-reinforced epoxy resin preparations was performed (Variolink Esthetic DC). Computed microtomography (µCT) was performed to assess the marginal/internal fit, as well as a mechanical fatigue test (20 Hz, initial load = 100 N/5000 cycles; step-size = 50 N/10,000 cycles until a threshold of 1500 N, then, the step-size was increased if needed to 100 N/10,000 cycles until failure or a threshold of 2800 N) to evaluate the restorations long-term behavior. Complementary analysis of the fracture features and surface topography in scanning electron microscopy was performed. Three-way ANOVA and Kaplan-Meier test (α = 0.05) were performed for marginal/internal fit, and fatigue behavior data, respectively. PS scanner, CR milling machine, and RC endocrowns resulted in a better marginal fit compared to their counterparts. Still, the PM machine resulted in a better pulpal space fit compared to the CR milling machine. Regardless of the scanner and milling machine, RC endocrowns exhibited superior fatigue behavior than LD ones. LD endocrowns presented margin chipping regardless of the milling machine used. Despite minor differences in terms of fit, the 'IOS' and 'milling machine' factors did not impair the fatigue behavior of endocrowns. Resin-composite restorations resulted in a higher survival rate compared to glass-ceramic ones, independently of the digital devices used in the workflow.

Magneto-dynamic tool for full arch immediate loading in post-traumatic restoration with narrow implants: A case report.

New surgical techniques using narrow, tilted implants positioned through a magneto-dynamic tool in guided surgery for a Toronto restoration. A 69-year-old woman wanted fixed rehabilitation to replace her removable complete dentures. A cone-beam computed tomography showed significant bone resorption in both the maxillary and mandibular regions. The plan was to load the entire upper arch with six implants immediately, while removable partial dentures were recommended for the lower jaw. The guided surgery project was aligned with the new dentures, and the laboratory created a printed cast with dental implant analogues in planned positions. A metal-reinforced denture was constructed, and surgery was performed to place six narrow implants using the magneto-dynamic instrument. The denture was directly screwed onto multi-unit abutments. Final rehabilitation was completed after 6 months. Narrow implants can be a good option for fixed, full-arch rehabilitations. Further research is needed to confirm these findings on a larger scale.

Influence of CAD-CAM milling strategies on the outcome of indirect restorations: A scoping review.

STATEMENT OF PROBLEM: The influence of computer-aided manufacturing (CAM) parameters and settings on the outcomes of milled indirect restorations is poorly understood. PURPOSE: The purpose of this scoping review was to summarize the current CAM systems, parameters, and setting changes, and their effects on different outcomes of milled indirect restorations and aspects related to their manufacture. MATERIAL AND METHODS: The protocol of this review is available online (https://osf.io/x28ps/). Studies that used at least 2 different parameters (CAM units, number of axes, digital spacers, or protocols with different rotatory instruments, grit-sizes, milling speed, or others) for milling indirect restorations were included. A structured search up to July 2023 was performed by 2 independent reviewers for articles written in English in LILACS, MEDLINE via PubMed, EMBASE, Web of Science, and Scopus. RESULTS: Of 1546 studies identified, 22 were included in the review. Discrepancies were found between the planned and actual measured cement space, with a decreasing linear relationship impacting restoration adaptation at different points. The CEREC MC XL milling machine was the most used system in the included studies, with variations in bur types, milling modes, and number of burs uses affecting internal fit and surface trueness. The results demonstrated the better adaptation of restorations made with 5-axis over 3-axis milling machines. Lithium disilicate and zirconia were the most commonly used materials, and crowns and inlays were popular designs. Marginal and internal adaptation were the primary outcomes assessed using the various techniques. CONCLUSIONS: The study presented a comprehensive exploration of CAM systems and parameters, and their influence on indirect restorations. The planned cement space was not properly reproduced by the milling. Bur characteristics can affect restoration fit and trueness. The 5-axis units seem to result in better-adapted restorations compared with 3- and 4-axis units.

Implant survival rate and marginal bone loss of 174 implants with different variables associated over a minimum observational period of 20 years: A retrospective study.

PURPOSE: To investigate the long-term implant survival rate and marginal bone loss (MBL) of implants with different variables associated over an observational period of at least 20 years. MATERIALS AND METHODS: Patients with at least one implant placed prior to 2001 were recalled and visited. Data on implant macro-design, prosthetic aspects, site distribution, and patient-related factors were collected. MBL was evaluated on intraoral X-rays and peri-implant soft tissue parameters were recorded. The patients were asked to fill out a questionnaire to evaluate their satisfaction with the treatment received. Descriptive statistics indicators were estimated. Analysis of variance and analysis of covariance models were used to investigate any differences in the MBL and peri-implant probing depth (PPD) among the variables. A chi-square analysis was performed to investigate any association between different types of prosthetic implant-supported rehabilitations and survival/success outcomes. RESULTS: Forty-one (41) patients and 174 implants were included with a mean observational period of 23.3 ± 2.8 years. The implant survival and success rates were 96.5% and 83.3% respectively, while 3.5% of early failures were detected. The lowest success rates were observed for implants supporting fixed full-arch rehabilitations (71.05%) and overdenture rehabilitations (86.11%). A mean MBL of 1.81 ± 0.71 mm and a mean PPD of 3.38 ± 1.62 mm were recorded. The interaction between the collected data with MBL and PPD did not reveal any statistically significant differences between the variables (p > 0.05). A statistically significant difference was recorded when analyzing the association between the different types of prosthetic implant-supported rehabilitations and success rates (p = 0.014), with fixed and removable full-arch rehabilitations presenting with lower success rates. Answers to the questionnaire showed a generally high level of satisfaction. CONCLUSIONS: Within the limits of this retrospective study and based on the results, an implant survival rate higher than 96% was observed after a mean observational period of 23.3 ± 2.8 years. Both the implant survival rate and MBL seemed stable after a mean observational period of 23.3 ± 2.8 years. Implants supporting fixed and removable full-arch rehabilitations seemed to present lower success rates over time. Implant rehabilitation seemed to provide patients with optimal long-term outcomes in terms of functional and psychological aspects.

Short-Term Effects of 3D-Printed Occlusal Splints and Conventional Splints on Sleep Bruxism Activity: EMG-ECG Night Recordings of a Sample of Young Adults.

(1) Background: This study aims to compare the effects of 3D-printed splints and conventional manufactured splints on sleep bruxism (SB) EMG activity. (2) Methods: Twenty-six patients (19 M, 7 F, 25.8 ± 2.6 years) were randomly allocated to a study group (3D splints) and a control group (conventional manufactured splints) and followed for a period of three months with night EMG-ECG recordings. Samples of the involved materials were analyzed for nanoindentation. The outcomes of interest considered were the overall SB index, the total amount of surface masseter muscle activity (sMMA), and general and SB-related phasic and tonic contractions. A statistical evaluation was performed with a confidence interval (CI) between 2.5% and 97.5%. (3) Results: Differences between groups with OAs were observed for general tonic contraction (p = 0.0009), while differences between recording times were observed for general phasic contractions (p = 0.002) and general tonic contractions (p = 0.00001). Differences between recording times were observed for the total amount of sMMA (p = 0.01), for general phasic contractions (p = 0.0001), and for general tonic contractions (p = 0.000009) during night recordings without OAs. (4) Conclusions: Three-dimensional splints seem to have a higher impact on SB-related electromyographic activity but not on the overall sleep bruxism index. The more regular surfaces offered by 3D splints could be related to phasic contraction stabilization.

Dynamic Navigation System vs. Free-Hand Approach in Microsurgical and Non-Surgical Endodontics: A Systematic Review and Meta-Analysis of Experimental Studies.

(1) Background: A Dynamic Navigation System (DNS) is an innovative tool that facilitates the management of complex endodontic cases. Despite the number of advantages and limitations of this approach, there is no evidence-based information about its efficiency in comparison with that of the traditional method in endodontics. (2) Objectives: We aimed to explore any beneficial effects of the DNS and compare the outcomes of DNS vs. free-hand (FH) approaches for non-surgical and microsurgical endodontics. (3) Methods: A literature search was conducted in August 2023 to identify randomized, experimental, non-surgical, and microsurgical endodontic studies that compared the DNS with FH approaches. The procedural time (ΔT, s), substance loss (ΔV, mm3), angular deviation (ΔAD, °), coronal/platform linear deviation (ΔLD_C, mm), and apical linear deviation (ΔLD_A, mm) were recorded and analyzed. Quality and risk of bias assessments were conducted according to the Quality Assessment Tool For In Vitro Studies. A meta-analysis was performed using mean difference and standard deviation for each outcome, and heterogeneity (I2) was estimated. p < 0.05 was considered significant. (4) Results: One-hundred and forty-six studies were identified following duplicate removal, and nine were included in the systematic review and meta-analysis. The overall risk of bias was classified as low. The DNS was found to be more accurate and efficient than the FH approach was, resulting in a significantly shorter operation time (p < 0.00001) and less angular (p ≤ 0.0001) and linear deviation (p ≤ 0.01). For substance loss, the advantage of the DNS was significant only for microsurgery (p = 0.65, and p < 0.005, for non-surgical and microsurgical procedures, respectively). A reduced risk of iatrogenic failure using the DNS was observed for both expert and novice operators. (5) Conclusions: The DNS appears beneficial for non-surgical and microsurgical endodontics, regardless of the operator's experience. However, appropriate training and experience are necessary to access the full advantages offered by the DNS.

Influence of Thickness and Thermocycling on Tensile Strength of Two Resin-Based Cements Used for Overdenture Bar-Type Attachments: An In Vitro Study.

PURPOSE: This study aimed to evaluate the tensile strength of five different thicknesses of two resin cements placed between two titanium surfaces, before and after ageing. MATERIALS AND METHODS: One hundred titanium 5 grade models composed of two surfaces simulating a semiprecision attachment for overdenture and its housing in the framework, were used. Samples were cemented using two different resin cements (SoloCem and OT-Cem). Five groups representing five different cement thicknesses (from 50 to 250µm) were created by varying the housing diameter. A half of the sample underwent to a tensile strength test 24h after luting, while the other half after 30000 thermic cycles from 5°C to 55°C. Shapiro-Wilk and ANOVA with post-hoc tests were performed to relate the tensile strength to the variables: cement type, thermal ageing and cement thickness (p <0.05). RESULTS: Statistical differences were found between the cements both at T0 and T1; the mean values of tensile strength of SoloCem were three times higher than those of OT-Cem. The thermic cycles determined a reduction of the tensile force values for both cements; statistical evidence was found only for the SoloCem except for the 100µm thickness group. Significant differences were also found between the cement thicknesses of both cements, with 50µm and 100µm expressed the best tensile strength. Most of the fractures were of cohesive nature. CONCLUSION: SoloCem showed a higher tensile strength than OT-Cem but has been more stressed by the ageing. For each group the cement thickness influenced the tensile strength values with an inverse relationship.

Endodontic microsurgery virtual reality simulation and digital workflow process in a teaching environment.

INTRODUCTION: Computer simulations are stimulating increased attention in dentistry. Augmented reality superimposes a virtual scenario over an existing reality and allows interaction with it. Virtual reality (VR) simulates a fully immersive situation permitting the user to experience the full environment in real time. Haptic technology provides tactile and realistic force feedback for the user to experience the immersive situation as if they were really there. Preclinical training is important to gain familiarity with difficult surgical techniques and to implement interpersonal skills. Developing a valid assessment of surgical simulation is challenging. This paper wants to present a newly realized VR simulation in endodontic microsurgery through the developmental digital workflow, the demonstration of a haptic VR scenario and student self-assessment and self-reflection feedback. METHODS: The volumes were exported in a stereolithography format to prepare and optimize in terms of shape and shade for the VR simulation. The graphics and touchable haptic solid were created using Virteasy Editor, which allows the transformation of 3D surfaces into graphical and volumetric haptic solids depending on their material (enamel, dentine, pulp and bone). Users were asked to execute the osteotomy and root-resection preparation. The assessment criteria were determined, and the feedback statements were created by a questionnaire with fixed answers. Objective and qualitative criteria for assessing the preparation were obtained from the literature. RESULTS: This study provides proof that it is possible to provide reliable and clinically relevant qualitative feedback with a VR simulator. CONCLUSION: VR simulation offers an innovative approach with all the benefits of clinical experience. It permits you to save your own progress and review the assessment at any time.

Ethanol Dehydrogenation over Copper-Silica Catalysts: From Sub-Nanometer Clusters to 15 nm Large Particles.

Non-oxidative ethanol dehydrogenation is a renewable source of acetaldehyde and hydrogen. The reaction is often catalyzed by supported copper catalysts with high selectivity. The activity and long-term stability depend on many factors, including particle size, choice of support, doping, etc. Herein, we present four different synthetic pathways to prepare Cu/SiO2 catalysts (∼2.5 wt % Cu) with varying copper distribution: hydrolytic sol-gel (sub-nanometer clusters), dry impregnation (A̅ = 3.4 nm; σ = 0.9 nm and particles up to 32 nm), strong electrostatic adsorption (A̅ = 3.1 nm; σ = 0.6 nm), and solvothermal hot injection followed by Cu particle deposition (A̅ = 4.0 nm; σ = 0.8 nm). All materials were characterized by ICP-OES, XPS, N2 physisorption, STEM-EDS, XRD, RFC N2O, and H2-TPR and tested in ethanol dehydrogenation from 185 to 325 °C. The sample prepared by hydrolytic sol-gel exhibited high Cu dispersion and, accordingly, the highest catalytic activity. Its acetaldehyde productivity (2.79 g g-1 h-1 at 255 °C) outperforms most of the Cu-based catalysts reported in the literature, but it lacks stability and tends to deactivate over time. On the other hand, the sample prepared by simple and cost-effective dry impregnation, despite having Cu particles of various sizes, was still highly active (2.42 g g-1 h-1 acetaldehyde at 255 °C). Importantly, it was the most stable sample out of the studied materials. The characterization of the spent catalyst confirmed its exceptional properties: it showed the lowest extent of both coking and particle sintering.

The Use of Diode Low-Power Laser Therapy before In-Office Bleaching to Prevent Bleaching-Induced Tooth Sensitivity: A Clinical Double-Blind Randomized Study.

INTRODUCTION: The present study aimed to investigate the effectiveness of low-level laser therapy (LLLT) use before in-office bleaching to prevent an increase in the risk and intensity of tooth sensitivity. METHODS: Thirty patients were selected. Before bleaching with 38% hydrogen peroxide, the participants were randomly divided into two groups of 15 subjects. Test group: the patients' teeth were subjected to a preliminary LLLT procedure by an 810 nm diode laser with 0.5 W for 30 s for an energy density of 15 J/cm2 and a group placebo. All patients were instructed to report their cold sensitivity experiences immediately, 1 h, 24 h, and 48 h after the end of bleaching via a VAS score. RESULTS: The results obtained show an increase in VAS values for both groups (290 and 490 vs. 224 and 234 of baseline time of test and placebo group, respectively); afterward, the VAS value seemingly decreases at 1 h after the end of bleaching, approaching the baseline VAS for the test group (274) in comparison to the placebo group. CONCLUSIONS: The use of preliminary diode LLLT could represent a valid possibility to reduce the occurrence of tooth sensitivity post-whitening and shorten recovery time in cases where tooth sensitivity occurs.

Influence of coloring techniques on the surface characteristics and color stability of a monolithic zirconia ceramic.

STATEMENT OF PROBLEM: The color of monolithic zirconia restorations is obtained by presintering or postsintering coloring techniques. However, studies on the differences in surface characteristics and their influence on color stability are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the influence of shading and staining techniques for a zirconia ceramic on the surface characteristics and colorimetric parameters (color difference, translucency, and whiteness index) after exposure to coffee or red wine and then polishing. MATERIAL AND METHODS: Ceramic disks (N=30; Ø10×1mm) were allocated into 3 groups: preshaded-shaded by the manufacturer (IPS e.max ZirCAD MT, shade A2); manually shaded-unshaded zirconia (IPS e.max ZirCAD MT, bleaching shade-BL) colored by the brushing technique, before sintering; stained-unshaded zirconia (IPS e.max ZirCAD MT BL) colored by the staining technique, after sintering. Spectrophotometric color assessments ensured the same initial perceived color (Vita Classical A2) for specimens included in the study (∆E00<1.77 acceptability threshold). Surface characteristics were assessed by scanning electron microscopy and atomic force microscopy. The specimens were immersed in coffee (n=5) or red wine (n=5) for 12 and 24 days and subsequently polished. The data were statistically and descriptively analyzed for color differences (∆E00), translucency parameters (TP00), and whiteness indexes for dentistry (WID), considering acceptability and perceptibility thresholds. RESULTS: The shaded groups found an irregular ceramic surface with uniformly sized zirconia crystals. The stained group found a glass-covered smoother surface. Significant alterations in color parameters (∆E00, TP00, WID) were observed with immersion in pigmenting beverages (P<.001) both after 12 days, and after 24 days. The shaded specimens had greater color alterations after immersion but benefited from the polishing procedure, which reduced color differences below an acceptable threshold in comparison with the baseline. Stained specimens had lower color alterations after immersion, but the polishing protocol was detrimental as it whitened the ceramic by subsurface exposure. CONCLUSIONS: The coloring technique influences the surface characteristics of zirconia ceramic and also the color parameters after exposure to colored beverages and polishing.

Comparing the accuracy of distinct scanning systems and their impact on marginal/internal adaptation of tooth-supported indirect restorations. A scoping review.

OBJECTIVE: To summarize the existing scientific evidence on the effect of distinct intraoral (IOS) and extraoral (EOS) scanners in terms of their accuracy for image acquisition and the marginal/internal adaptation of indirect restorations. METHODS: The protocol of this scoping review is available online (https://osf.io/cwua7/). A structured search, with no date restriction, was performed in LILACS, MEDLINE via Pubmed, EMBASE, Web of Science, and Scopus, for articles written in English. The inclusion criteria were studies that considered at least two scanners, regardless of method (intra or extraoral), for the production of tooth-supported restorations. Two independent and blinded researchers screened the studies, collected and analyzed the data descriptively. RESULTS: 103 studies were included (55 on marginal/internal adaptation, 33 on accuracy, 5 on both outcomes, and 10 reviews). Most of them, shown clinically acceptable adaptation (<120 µm). Factors commonly related to the performance of scanners are: use of anti-reflection powders, method of image acquisition, and restoration/tooth characteristics. The need of anti-reflection powders was controversial. Different scanning principles seems to result on similar performance; IOS that combine them could be promising. The most explored systems were Omnicam - IOS, and inEos X5 - EOS, which showed similar performance on marginal/internal adaptation. Scarce studies explored the performance of EOS systems, especially in terms of accuracy. Different restoration designs as single-unit seemed not to modify the performance of scanners. Limited information is available regarding the planned cement space, restorative material and design (multi-unit restorations), as also techniques to measure adaptation. CONCLUSIONS: Digital scanners are valid approaches to obtain accurate impressions resulting in clinically acceptable restorations. Systems that uses combined principles of image acquisition seems promising for optimal performance. Based on high discrepancy, the quality of evaluated evidence is low, and well-designed studies are still encouraged, especially considering validated IOS/EOS as a control comparison condition.

Evaluation of Er,Cr:YSGG laser technique for fiber post removal of endodontically treated teeth using micro-computed tomography.

Various clinical techniques such as removal kits, ultrasonic tips, burs, and drills, have been used for fiber post removal in endodontically treated teeth. In most clinical cases, the dental practitioners prefer to use ultrasonic tips, despite the heat generation and the formation of microcracks induced in the radicular dentin. The purpose of this study was to investigate the effectiveness of using erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser (2780 nm) as an alternative fiber post removal technique and to compare it to an ultrasonic method using micro-computed tomography (micro-CT). The operating parameters of the X-ray tube were set to 50 kVp and 300 mA. This approach allowed the generation of 2D lateral projections that were then used to reconstruct the 3D volume in DICOM format. Fiber posts were removed from 20 endodontically treated single-rooted premolars (n = 10) using an ultrasonic vibrator with diamond-coated ultrasonic tip (control method), or Er,Cr:YSGG laser irradiation protocol; average power 2.5 W, repetition rate 20 Hz, pulse duration 140 µs, 40% air and 20% water, and close-contact mode. The number of sections with newly formed microcracks, the loss of dentinal tissue, the amount of the residual resin cement, and the removal time were evaluated for both methods. The data were analyzed using paired t-test, Wilcoxon signed-rank and Mann-Whitney U tests at level of significance a = .05. In the laser-treated group the parameters regarding microcracks formation (21 ± 16) and removal time (4.7 ± 1.1 min) were advantageous compared to the ultrasonic-treated group (42 ± 27 and 9.2 ± 1.0 min, respectively), indicating that Er,Cr:YSGG laser could be an alternative fiber post removal technique.