Different materials and cements have been proposed for overlay restorations in the last decade. The present study aimed to better understand the mechanical behavior of an overlay interface under load through finite element analysis (FEA). A lower molar was endodontically treated, restored with an overlay restoration after build-up and then scanned with micro-CT (Skyscan 1172, Bruker) and segmented (Mimics 24.0) in the following volumes: enamel, dentin, restorative material, cement, build-up material. The volumes were optimized for FEA and exported in a simulation software (LS Dyna). Three different restorative materials were tested: Lithium Disilicate (DL), Cubic Zirconia (CZ), Reinforced Composite (RC). Two cements were tested for each restorative material: dual-cure resin cement (DR) and flowable composite (FC). After simulating shrinkage stress of resin materials, accordingly to manufacturer data, the model was loaded axially and horizontally with a sphere. Shear and tensile stresses were recorded, and color-maps were created to better understand stress distribution at the adhesive interface. All tested scenarios showed similar shear and tensile stress distribution at the cement interface. However, RC showed a significantly better distribution (lower peak stresses) compared to other materials. This might be due to the mechanical properties similar to the ones of tested cements, that create a homogeneous force distribution. The greatest shear stresses were located at the interproximal boxes of the preparation, above all when ceramic materials were tested. No significant differences were observed between DR and FC. Having a homogeneous combination of materials might significantly improve the tooth-restoration complex mechanical resistance to loads, above all at the adhesive interface, with subsequent better clinical prognosis. Further studies are necessary to confirm the obtained results when cyclic fatigue is simulated.

The aim of the present study was to assess marginal gap presence at enamel and dentin margins in V class cavities restored with flowable materials with different viscosity, before and after thermal fatigue. The null hypotheses tested were that, substrate, materials and thermal ageing, are not able to influence marginal gap presence in V class cavities. 30 intact single-rooted canines were selected. On the buccal surface, a standardized class V cavity was created with the following design: 5 mm extension in the corono-apical direction, 3 mm mesio-distal width, 2 mm depth, cervical margin of 90° and coronal margin with a 45° bevel and an extension of 1.5 mm. Before doing the restorations a self-etch adhesive (Clearfil SE Bond 2, Kuraray) was applied after 15 s selective enamel etching. Bonded specimens were then divided into three groups (n=10), according to the material used for class V restoration: - G1: Majesty ES Flow SuperLow (Kuraray) - G2: Majesty ES Flow Low (Kuraray) - G3: Clearfil Majesty ES-2 (Kuraray) All materials were applied following the horizontal layering technique. After curing, all samples were finished and polished employing the same protocols for all groups. The presence of marginal gaps at enamel and dentin finishing line was evaluated before and after thermocycling (10000 cycles between 5°C and 55°C) using OCT (Optical Coherence Tomography) images. Five images of each restored tooth were obtained. Images were analyzed using ImageJ software and the presence of a gap was quantified along the enamel/dentin restoration interface. Obtained data in μm for the different groups were statistically analyzed with ANOVA test and Tukey's post-hoc test using Stata12 software. Significance was set for p<0.05. Three-way ANOVA showed significant differences in the data obtained for the variable substrate, material and ageing. Enamel performed better than dentin in all groups, aging affects the gap presence over time and flowable materials reduced gap presence in comparison to nanohybrid composite. Also, the interaction between the variable materials and ageing showed significant results (p=0.001). The initial null hypotheses were rejected, since the tested flowable resin composites, independent of their viscosity, showed less gap formation than nanohybrid composites at the enamel and dentin margin in a class V restoration. In addition, enamel guaranteed a better performance of the restorative materials, both before and after ageing.

The objective of this study is to evaluate the occurrence of coronal dentinal micro-cracks after access cavity refinement using high-speed burs and ultrasonic tips by means of micro-computed tomography (micro-CT) analysis. In this study, 18 mandibular cadaveric incisors were divided into two groups according to the protocol of the preparation of the conventional access cavity. The diamond bur 802 # 12 was used until the perforation of the pulp roof. Then, the Endo-Z bur was used for the group #1 and the ultrasonic tip Start-X # 1 for the group #2 to finish and refine the access cavity. The preparation time of each access cavity has been recorded. The teeth underwent a micro-CT scan before and after the preparation of the access cavity. Fisher's exact test, the Chi-square test, the Kolmogorov–Smirnov test, the Mann–Whitney test, and the Student's test were used for statistical evaluation. The percentage of teeth with new micro-cracks is not significantly different between the two groups (-p-value < 0.5). The number of newly formed micro-cracks and extension size were not significantly different between the two groups. The direction of extension of the micro- cracks was occluso-apical. The average duration of the access cavity is significantly smaller with the Endo-Z system (-p- value < 0.001). The roughness of walls surfaces has no statistically difference between the two groups. The use of ultrasound, although slower, is considered safe in the creation of dentinal micro-cracks, in the preparation of the access cavity.

The aim of the present laboratory study was to three-dimensionally evaluate the interfacial adaptation of flowable materials with different flowability in a simulated deep-margin elevation scenario, before and after cyclic fatigue. The null hypothesis tested was that the substrate of the cervical margin, enamel or dentin, the material employed, and the simulated ageing did not influence the quality of the marginal sealing in terms of gap presence. 50 extracted premolars were selected, and two class II cavities were prepared: one mesial, with the cervical margin 1 mm above CEJ (enamel margin) and one distal, with the cervical margin 1 mm below CEJ (dentin margin). After performing adhesive procedures using a self-etch adhesive system with enamel selective etching, specimens were divided into 5 groups (n=10) according to the materials employed for horizontal margin relocation. G1: nanohybrid composite (Clearfil ES2,Kuraray); G2: medium viscosity flowable composite (Majesty ES2 Low-Flow, Kuraray); G3:low viscosity flowable composite (Majesty ES2 Superlow-Flow, Kuraray); G4: conventional viscosity flowable composite (Tetric Flow, Ivoclar); G5: CAD/CAM inlay (Katana Avencia, Kuraray). All restorations, except for G5 were finalized using an oblique layering with a nanohybrid composite. To reveal interfacial gap progression specimens were scanned with a micro-CT (SkyScan 1172), before and after 500000 cycles of thermomechanical chewing simulation (50 N, 1 Hz). Data were imported into Mimics software after smoothing and region growth: only the external gap of the relocation (2 mm) was considered in the analysis. Obtained STL optimal quality masks were imported into Geomagic software for noise removal and volume calculation. Interfacial gap progression, expressed in mm3, was collected and statistically analyzed with ANOVA test (α<0.05). The mean external gap augmentation was tri-dimensionally measured as volume. Three-way ANOVA showed significant differences in the data obtained for the variable substrate, material and ageing. Enamel performed better than dentin in all groups, ageing affected the gap presence over time and flowable materials reduced gap presence in comparison to nanohybrid composite. However, no differences were found between the different tested flowable composites. The initial null hypothesis was rejected since tested flowable resin composites, independently from their viscosity, showed less gap formation than nanohybrid composites at the enamel and dentin margin in deep second class. In addition, enamel guaranteed a better performance of the restorative materials both before and after ageing. Artificial ageing significantly affects the presence of volumetric gap at the interface.

Purpose: The aim of this in vitro study was to investigate differences in surface wear of enamel-material and dentin-material bonded interfaces obtained from upper molars samples and subjected to cycling occlusal load. Methods: Forty-eight flat specimens of enamel-material and dentin-material bonded interfaces were prepared using different restorative materials with both CAD-CAM techniques and direct techniques. After the bonding and cementation procedures specimens were tested with a chewing machine with a stainless-steel ball on flat sliding contact (20N loads, 50.000 cycles). Wear analysis and comparison of the enamel or dentin substrates and the three restorative materials was performed using a 3D profilometer and analyzed with ANOVA test and post-hoc comparison procedures. Finally worn surfaces were examined with optical microscopy. Results: Statistical analysis after simulated chewing cycles identified a significant influence of the factor “substrate” (p<0.05) and of the factor “restorative material” (p<0.05). The enamel results in being more wear resistant than dentin, and also more resistant than all the restorative materials tested. Considering the materials, the most severe wear loss was observed with micro-hybrid composite paste. CAD-CAM materials showed a wear rate significantly better both in association with enamel and dentin. An interesting wear pattern was found at the bonded interface level and the oval shapes obtained from the profilometer images underlined a repetitive wear pattern with the central zone more consumed and decreasing depth moving towards the perimeter. Initials signs of cracks were showed in enamel interfaces at the optical microscopy analysis. Conclusions: Both the dental substrate and the restorative material significantly affect the wear behavior of a toothmaterial interface after cyclic fatigue. Thus, the initial null hypotheses were rejected.

Using a material that optimizes marginal seal when using a margin elevation technique to manage deep class II cavities should enhance clinical outcomes.

OBJECTIVES:In patients affected by dimensional discrepancy between size of anterior maxillary and mandibular teeth, orthodontic therapy could be necessary to solve occlusal problems. However, anterior restorations are indicated to finalize the aesthetic aspect of the therapy. The aim of the present retrospective clinical study was to evaluate the long-term outcomes of direct additive composite restorations performed to correct anterior teeth discrepancies persisting after orthodontic treatment. METHODS:Patients with dimensional teeth discrepancy, subjected to a combined orthodontic-restorative treatment, between January 2009 and January 2019, were recalled for the present retrospective evaluation and divided in two groups according to the restoration performed: G1) diastema closure; G2) tooth shape modification. All patients, after ortho therapy, were subjected to a standardized restorative rehabilitation of the anterior area. All restorations were performed by a single experienced operator employing the same materials. During recall visits, two calibrated examiners evaluated the restorations and recorded USPHS data. Kaplan-Meier estimator and Cox-regression analysis were performed. Statistical significance was set for p < 0.05. RESULTS:53 patient were included, with a total of 169 restoration (G1:110;G2:59). The mean study time period was 5 year (ranging from 6 month to 10 years). The overall survival rate of additive restoration was 2,59% (G1:2,07%; G2:0,47 p < 0.05). Chipping of the material was the most frequent adverse event (G1:13,64%; G2:1,69), followed by composite wear (G1:9,09%; G2:5,17). CONCLUSIONS:Based on the obtained results, good clinical performances were shown at a 5-year interval. A low number of failures were collected and most of them were classified as reparable. Only few cases needed complete reintervention. CLINICAL SIGNIFICANCE:Showing that a direct approach in restoring anterior teeth for diastema closure or shape modification is a valid alternative in terms of durability and aesthetics to more invasive procedure such as indirect restorations.

Purpose The aim of this study is to test the performance of a new bi-dimensional diamond dosimeter, manufactured within the DIAPIX and IRTP Italian INFN projects, in pre-treatment verification of high conformal plans. Methods DIAPIX dosimeter consists of two pCVD diamond matrices (12 × 12 pixels, 2 mm pitch) coupled together covering a total area 2.5 × 4.8 cm2 with 1 mm dead space between matrices [ [1] Bartoli A. Cupparo I. Baldi A. Scaringella M. Pasquini A. Pallotta S. et al. Dosimetric characterization of a 2D polycrystalline CVD diamond detector. JINST. 2017; 12: C03052 Google Scholar ]. Dosimetric verifications of lung plans delivered with Cyberknife (CK) and 6 MV photon Elekta Synergy BM (EBM) were compared with the plans calculated with Multiplan Cyberknife and Monaco Elekta TPS. Since some pixels, mainly concentrated in a single matrix, were not fully operational, two measurements in gun-target and three in latero-lateral directions were necessary to cover the full EBM planning area. Bad pixels in both matrices were masked and they were assigned the average value of neighbour pixels and a global 3 × 3 pixel filter was applied. Dose distributions were registered with intensity-based algorithms and γ -index was evaluated with an in-house developed MATLAB routine and focused on the best performing matrix. The passing rate ( γ < 1 ) was evaluated for 3%/3 mm criteria. Results CK passing rate over the whole dosimeter was 72% and for the EBM was 77%. These values increase to 84% and 85% for CK and EBM respectively just selecting the best performing matrix (Fig. 1). Moreover γ analysis showed that pixels corresponding to the edge of the matrix have a different behaviour and excluding them the passing rate increases to 93% for CK and 95% for EBM. Conclusions The aim of this study is to test the performance of a new bi-dimensional diamond dosimeter, manufactured within the DIAPIX and IRTP Italian INFN projects, in pre-treatment verification of high conformal plans. DIAPIX dosimeter consists of two pCVD diamond matrices (12 × 12 pixels, 2 mm pitch) coupled together covering a total area 2.5 × 4.8 cm2 with 1 mm dead space between matrices [ [1] Bartoli A. Cupparo I. Baldi A. Scaringella M. Pasquini A. Pallotta S. et al. Dosimetric characterization of a 2D polycrystalline CVD diamond detector. JINST. 2017; 12: C03052 Google Scholar ]. Dosimetric verifications of lung plans delivered with Cyberknife (CK) and 6 MV photon Elekta Synergy BM (EBM) were compared with the plans calculated with Multiplan Cyberknife and Monaco Elekta TPS. Since some pixels, mainly concentrated in a single matrix, were not fully operational, two measurements in gun-target and three in latero-lateral directions were necessary to cover the full EBM planning area. Bad pixels in both matrices were masked and they were assigned the average value of neighbour pixels and a global 3 × 3 pixel filter was applied. Dose distributions were registered with intensity-based algorithms and γ -index was evaluated with an in-house developed MATLAB routine and focused on the best performing matrix. The passing rate ( γ < 1 ) was evaluated for 3%/3 mm criteria. CK passing rate over the whole dosimeter was 72% and for the EBM was 77%. These values increase to 84% and 85% for CK and EBM respectively just selecting the best performing matrix (Fig. 1). Moreover γ analysis showed that pixels corresponding to the edge of the matrix have a different behaviour and excluding them the passing rate increases to 93% for CK and 95% for EBM.

We present pressure profiles of galaxy clusters determined from high-resolution Sunyaev-Zel'dovich (SZ) effect observations of 14 clusters, which span the redshift range of 0.25 < z < 0.89. The procedure simultaneously fits spherical cluster models to MUSTANG and Bolocam data. In this analysis, we adopt the generalized NFW parameterization of pressure profiles to produce our models. Our constraints on ensemble-average pressure profile parameters, in this study gamma, C-500, and P-0, are consistent with those in previous studies, but for individual clusters we find discrepancies with the X-ray derived pressure profiles from the ACCEPT2 database. We investigate potential sources of these discrepancies, especially cluster geometry, electron temperature of the intracluster medium, and substructure. We find that the ensemble mean profile for all clusters in our sample is described by the parameters [gamma, C-500, P-0] = [0.3(-0.1)(+0.1), 1.3(-0.1)(+0.1), 8.6(-2.4)(+2.4)], cool core clusters are described by [gamma, C-500, P-0] = [0.6(-0.1)(+0.1), 0.9(-0.1)(+0.1), 3.6(-1.5)(+1.5)] and disturbed clusters are described by [gamma, C-500, P-0] = [0.1(-0.0)(+0.1), 1.5(-0.2)(+0.1), 13.8(-1.6)(+1.6)]. Of the 14 clusters, 4 have clear substructure in our SZ observations, while an additional 2 clusters exhibit potential substructure.

A cost-effective lateral beam splitting photovoltaic system coupling a Si cell and a InGaAs photodiode through a long-pass dichroic filter has been designed, manufactured and tested under illumination with a Sun simulator and direct solar irradiation. Two filters with different cut-off wavelengths have been considered: 950nm and 1100nm, best efficiencies are achieved with the 950nm cut-off one due to lower reflectance losses in the high energy spectral range. The system, read-out in two-terminal configuration both in parallel and in series, proved to double the efficiency of the Si cell alone in case of high air masses.

A bidimensional pixelated dosimeter composed of two polycrystalline Chemical Vapour Deposited diamond films, 2.5 × 2.5 cm2 each placed aside, has been manufactured so as to obtain a detector with a 2 mm pitch over a total active area of 5.0 × 2.5 cm2. We performed the dosimetric characterization of the detector with an Elekta Synergy linear accelerator using a 6 MV photon beam. Uniformity maps, rise and fall times, signal repeatability, dependence on dose rate, linearity with dose and sensitivity show that the device is suitable for dosimetric evaluations in Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy (VMAT) treatments. Then, a first quantitative evaluation of the dose distribution in a lung VMAT treatment plan has been carried out, by comparing data from our device with Treatment Planning Sistem values by means of a Γ test, with promising results.

Diamond has a potential for dosimetry in advanced radiotherapy techniques, being a solid-state nearly tissue equivalent material, with the possibility to be grown in large diameter wafers by Chemical Vapour Deposition (CVD). A large-area bidimensional dosimeter made of up to two detector-grade adjacent 2.5×2.5cm 2 polycrystalline Chemical Vapour Deposited (pCVD) diamond samples, each equipped with a 12×12 matrix of contacts and connected to a custom-made electronic read-out system, has been manufactured in view to achieve fast dynamics as well as spatial and time resolutions required in advanced radiotherapic techniques, such as Volumetric Modulated Arc Therapy (VMAT). The device has been used to extract a 2D map of a VMAT lung plan, showing promising performances.

Introduction: The aim of the study is the characterization of a large area dosimeter (DIAPIX) used for pretreatment verification of intensity modulated treatment plans.

Morphology is often used to infer the state of relaxation of galaxy clusters. The regularity, symmetry, and degree to which a cluster is centrally concentrated inform quantitative measures of cluster morphology. The Cluster Lensing and Supernova survey with Hubble Space Telescope (CLASH) used weak and strong lensing to measure the distribution of matter within a sample of 25 clusters, 20 of which were deemed to be relaxed based on their X-ray morphology and alignment of the X-ray emission with the BCG. Towards a quantitative characterization of this important sample of clusters, we present uniformly estimated X-ray morphological statistics for all 25 CLASH clusters. We compare X-ray morphologies of CLASH clusters with those identically measured for a large sample of simulated clusters from the MUSIC-2 simulations, selected by mass. We confirm a threshold in X-ray surface brightness concentration of C>0.4 for cool-core clusters, where C is the ratio of X-ray emission inside 100 kpc/h70 compared to inside 500 kpc/h70. We report and compare morphologies of these clusters inferred from Sunyaev-Zeldovich Effect (SZE) maps of the hot gas and in from projected mass maps based on strong and weak lensing. We find a strong agreement in alignments of the orientation of major axes for the lensing, X-ray, and SZE maps of nearly all of the CLASH clusters at radii of 500 kpc (approximately 0.5R500 for these clusters). We also find a striking alignment of clusters shapes at the 500 kpc scale, as measured with X-ray, SZE, and lensing, with that of the near-infrared stellar light at 10 kpc scales for the 20 "relaxed" clusters. This strong alignment indicates a powerful coupling between the cluster- and galaxy-scale galaxy formation processes.