In the current orthodontic and prosthodontics practice, study models made of plaster are being used to provide a three-dimensional view of the patient’s occlusion and allow the clinician to analyze, diagnose, or monitor anomalies. With the introduction of intraoral and extra oral digital impressions, it is now possible to obtain digital study models of the patients’ dental arches. Digital models can be obtained in a physical hardcopy via 3D printing or rapid prototyping. Although, professional 3D printers require a high initial set-up cost, low cost 3D printers can provide similar quality products. The aim of this study is to investigate the accuracy of physical dental models reconstructed from digital data by two rapid prototyping techniques. For this purpose twenty mandibular and maxillary conventional plaster models from randomly chosen subjects were selected and served as the gold standard. The casts were digitized using a 3D scanner and .stl surface models were acquired; the virtual model was adjusted for reconstruction using dedicated software, thus obtaining the CAD model of the casts. The CAD models were reconstructed using a 3D fused deposition modeling (FDM) printer, a RepRap FDM printer and an inverted stereolithography printer. The reconstructed models were digitized using a laboratory 3D scanner and the resulting Mesh datasets were compared with the CAD model using inspection software. The mean systematic differences for the 3D comparison of the reconstructed models were 0.207 mm for the stereolithography models, 0.156 mm for the FDM models, and 0.128 mm for the RepRap models. Although a technology proved the ability to manufacture a dental model with accentuated morphology, the results demonstrate that replicas of plaster casts are influenced by problems linked to the size of the detail to be reproduced, which is often similar to or finer than the fabrication layer.

This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.

The unprecedented climate of the COVID-19 pandemic has some restrictions on oral care operational services, which heavily impacted the delivery of aerosol generating procedures (AGPs). This led the health authorities to set up guidelines and policies that should be followed to minimize the virus spread and ensure safe and effective dental care delivery. This systemic review aimed to evaluate the current guidelines and strategies in providing safe dental services and ensuring efficacy of the current universal personal preventive and protective measures, as well the impact that this outbreak might have on practicing the dental profession in full scope. The review focus questions were as follows: are the current guidelines and measures in literature mitigated enough to ensure safe and effective oral care delivery to patients during the COVID-19 pandemic? Is it possible to highlight the essential and fundamental cross-infection control measures and policies? Twenty articles were chosen out of 180,248 after the inclusion and exclusion criteria were applied in the period between January 1st and August 1st 2020. Our results highlighted effective safety measures that can be implanted in protecting healthcare professionals and patients and ensuring optimal dental care delivery in a safe and healthy environment, taking into consideration the risk assessment and management of AGPs. In conclusion, informative updated standardized policies and protocols are required when more knowledge on the virus behavior keeps evolving. Moreover, there is a need for evidence-based protective measures to be modified on a regular basis to be followed, until a safe vaccine is produced.

The replacement of classical fillings, especially in the posterior area with different types of inlays has become a common solution used in order to improve all parameters which insure a long lasting treatment. Vrious ceramic materials and systems are available, but so far an ideal ceramic material suited for all clinical situations, has not been found. The range of ceramic materials as: lithium disilicate, aluminum oxide, zirconium oxide and hybrid ceramics enhance the possibilities of using ceramic inalys in various clinical situations. Marginal adaptation is one of the most important conditions for long-term success for any type of material. The marginal discrepancy of fixed restorations is one of the main factors which lead to failure of the prosthetic treatment.The purpose of the present study is to compare a 2D and 3D method for evaluating the marginal fit for pressed lithium dislicate inlays (Emax). The two used methods were: SEM- electronic microscopy and micro CT.

The main goal of the present study is to compare the marginal fit of two different kind of pressed materials: a partially crystalline thermoplastic resin reinforced with ceramic particles (BioHPP) and lithium disilicate (EMax), through the use of the microCT technique. After extraction of four caries-free mandibular first molars, first class inlay cavities were prepared. For each tooth two inlays were manufactured- one by using BioHPP thermoplastic resin (n=4) and one by using Emax Press lithium disilicate (n=4). The marginal gap was analyzed circumferentially at the occlusal margin using a Bruker micro CT, by measuring the distance at the occlusal limit of the cavities, between the restoration and the tooth in several points for every surface of each tooth before cementing. Data were analyzed statistically using the Mann-Whitney U test and the Pearson�s correlation coefficient (a=0.05). A significant statistical difference was found between the marginal gap size obtained for BioHPP and Emax inlays (p[0.001). For the Emax inlays the marginal gap had an average of 72mm, while for BioHPP the average was 94 �m. Both types of used materials offer a good marginal adaptation. By summing up the gathered data we can conclude that the pressed ceramics shows a better marginal fit than the pressed resin, probably because of the different processing methods: sintering versus polymerizing with different shrinkage values.

Diabetes-related cognitive dysfunction is considered a long-term complication of diabetes. In this cross-sectional study was studied the relationship between cognitive dysfunction (assessed by using two standardized questionnaires), lipid profile parameters and fatty free acids intake, in outpatients, hospitalized for their periodical control. The Mini-Mental State Exam (MMSE) and The Montreal Cognitive Assessment (MoCA) score were related to the body mass index (BMI), high density cholesterol (HDLc), glycated hemoglobin (Hb A1c) and intake of choline and eicosapentaenoic acid (all Ps [ .05, excepting the relationship between MMSE and HDLc). The implications of FFA intake in dementia development, in type 2 diabetics, is important for disease management and prevention.

Bone reconstruction is a complex process which involves an osteoconductive matrix, osteoinductive signaling, osteogenic cells, vascularization and mechanical stability. Lately, to improve the healing of the bone defects and to accelerate the bone fusion and bone augmentation, bioceramic composite materials have been used as bone substitutes in the field of orthopedics and dentistry, as well as in cosmetic surgery. Of all types of bioceramics, the most used is hydroxyapatite, because of its similar properties to those of the human bone and better mechanical properties compared to b-tricalcium phosphate [1]. Currently, the most used raw materials sources for obtaining the hydroxyapatite are: bovine bone, seashells, corals, oyster shell, eggshells and human teeth. There are two common ways to obtain hydroxyapatite: synthetically and naturally. Generally, for the improvement of the mechanical properties and the structural one, hydroxyapatite is subjected to the sintering process. Considering the disadvantages of hydroxyapatite such as poor biodegradation rate, b-TCP has been developed, which has some disadvantages too, such as brittleness. For this reason, the aim of this study is to look into the effect of adding magnesium oxide on the sintering behavior, the structure and the mechanical properties of the hydroxyapatite-tricalcium phosphate composites.

Background: Once inserted and osseointegrated, dental implants become ankylosed, which makes them immobile with respect to the alveolar bone. The present paper describes the development of a new and original implant design which replicates the 3D physiological mobility of natural teeth. The first phase of the test followed the resistance of the implant to mechanical stress as well as the behavior of the surrounding bone. Modifications to the design were made after the first set of results. In the second stage, mechanical tests in conjunction with finite element analysis were performed to test the improved implant design. Methods: In order to test the new concept, 6 titanium alloy (Ti6Al4V) implants were produced (milling). The implants were fitted into the dynamic testing device. The initial mobility was measured for each implant as well as their mobility after several test cycles. In the second stage, 10 implants with the modified design were produced. The testing protocol included mechanical testing and finite element analysis. Results: The initial testing protocol was applied almost entirely successfully. Premature fracturing of some implants and fitting blocks occurred and the testing protocol was readjusted. The issues in the initial test helped design the final testing protocol and the new implants with improved mechanical performance. Conclusion: The new prototype proved the efficiency of the concept. The initial tests pointed out the need for design improvement and the following tests validated the concept.