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Our study aims to investigate the acid etching treatment effects applied on dental structures, considering their surface properties. We have used a liquid PA in a concentration of 36.1% wt. (36.1% PA) and a gel PA with 35% wt. (35% PA) active compound as etching agents. These substances were applied to the human teeth for a maximum of 15 seconds. As investigation methods, the surface roughness was determined based on atomic force microscopy (AFM), and we analyzed the surface morphology in detail using scanning electron microscopy (SEM). Then, we analyzed the hydrophile character of the dental structure by experimentally measuring the contact angle (CA) and computed the surface energy (SFE). Following this study, we can say that both investigated etching treatments produce the demineralization of both enamel and dentine structures, with a higher degree in the case of liquid PA (36.1%). Increasing the values for the surface free energy will favor better infiltration and polymerization of the bonding systems. [ABSTRACT FROM AUTHOR]

Aim of the study: The aim of this study is to evaluate the resistance of different marginal fit geometries for a provissional fixed dental prothesis, which can have an impact on the periodontal health. Materials and methods: Acording to the principles of the tooth preparation, four types of marginal design were made: feather edge, rounded shoulder, chamfer and heavy chamfer. Using a direct technique, prepared teeth were poured into metal abutments, temporary composite resin crowns were made and cemented. All four abutments were analyzed using theoretical and experimental methods. Results: The results obtained from the mechanical tests were more reliable than those obtained from numerical analyses. A chamfer marginal finish line a pre prosthetic periodontal therapy can have greater impact on the soft tissue healing process. Conclusions: These preliminary studies enhance the idea of differentiating preparations for distinctive alternative prosthetic treatment plans. [ABSTRACT FROM AUTHOR]

This article, published in the Romanian Journal of Oral Rehabilitation, examines the impact of various fabrication methods on the flexural strength of complete dentures. The study compares three different technologies: the classic press packing process and traditional polymerization, the injection technology and polymerization under constant pressure, and an original suction-injection process with polymerization under continuous pressure. The findings indicate that the suction-injection method with sustained pressure polymerization produces superior results compared to the other two methods. The study highlights the importance of selecting the appropriate fabrication technology to ensure the durability and strength of denture bases. [Extracted from the article]

This article explores the application of Optical Coherence Tomography (OCT) in evaluating the temperature variations during the sintering process of dental prosthetics. The study utilized OCT to examine metal-ceramic restorations at different sintering temperatures and generated cross-sectional images to identify defects and structural changes. The findings demonstrate that OCT can provide valuable insights into the impact of temperature deviations on ceramic microstructure, making it a useful tool for quality control in dental laboratories. The article suggests that integrating OCT into routine practices can offer a rapid, accurate, and non-destructive means of assessing sintering temperatures and detecting defects in dental ceramics. [Extracted from the article]

This article discusses a study on the mechanical assessment of metal structures in dental prostheses that were repaired using laser welding and plasma welding. The study found that both methods can be used for repairs, but laser welding offers higher mechanical strength compared to plasma welding. Factors such as surface preparation, wire diameter, and the mechanical properties of the alloy used also influence the success of the repairs. The article concludes that laser welding is a viable option for repairing metal frameworks in dental prostheses, despite the samples fracturing under high mechanical loads. [Extracted from the article]

Copyright of dentalTarget is the property of dentalTarget and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of dentalTarget is the property of dentalTarget and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this mini-review was to describe the CAD/CAM systems, their principles and their equipment, to highlight the major historical milestones in the development stages of dedicated dental CAD/CAM systems, and to identify the advantages/ disadvantages of using optical impressions compared to conventional impressions. This technique provides benefits in both directions of the designing and manufacturing process of a prosthetic restoration, i.e. in clinical and technological sectors. The main clinical benefits are strength, aesthetics, comfort, while the technical ones assure an easier, faster and more accurate fabrication process. [ABSTRACT FROM AUTHOR]

The mechanical behavior of periodontal ligaments belongs nowadays to the field of biomechanics. In this study, we investigate the vibrations of periodontal ligaments (PDL) under load as, by identifying the parameters of the system, one can obtain a series of data reflecting coupling of the tooth with the alveolar region. We started from the hypothesis that a tooth fixed in the alveolus and periodontal tissue is equivalent to an oscillating system with several degrees of freedom. We investigated the periodontal support of the abutments on which a three-element FPD was manufactured using the ultrasonic Doppler method of measuring tooth movement, known as a new testing method providing quantitative and accurate results. [ABSTRACT FROM AUTHOR]

The present research aims at studying the dynamic behavior of the abutment teeth of a dental phantom supporting a fixed metal-polymeric and porcelain-fused-to-metal partial denture. Simulation of a clinical situation was created using a Frasaco typodont on which the 2 teeth were positioned first freely then fixed with a siliconic material, which resulted in different damping and elastic constants. In the in vitro created cases, a laser Doppler vibrometer (LDV) was used as a scientific instrument for non-contact vibration measurements of the surface of abutment teeth. The laser beam from LDV was directed to the surface of interest, and the vibration amplitude and frequency were extracted from the Doppler shift of the reflected laser beam frequency, due to the surface motion. The output of LDV was a continuous analogue voltage, directly proportional to the target velocity component along the direction of the laser beam. [ABSTRACT FROM AUTHOR]

Aim. To evaluate the degree of knowledge, acceptance and usage of dental CAD-CAM systems among dental technicians based in Romania and to identify the factors which contribute/ inhibit the usage of this technology. Materials and methods. A web-based survey containing 16 questions was distributed by means of an online social platform to dental technians practising in Romania. The questionnaire contained three different sections, focusing on topics related to the level of usage and common practices on subtractive manufacturing, demographics and perception of impact. Descriptive statistical analysis was used to quantify and interpret the resulting data. Results and disscusion. A number of 84 complete responses was obtained. The majority of respondents affirmed that they have theoretical knowledge about this technology (97.7%); also, a high number of dental technicians (54.8%) reported that they currently use some form of CAD-CAM technology in their laboratories. Most of the surveyed technicians acquired their knowledge in this domain through self-documentation, mainly using CAD-CAM to manufacture fixed restorations (91.3%). The majority of dental technicians (87%) consider that introduction of subtractive manufacturing systems has had a beneficial impact on their profession. Conclusions. Currently, a fairly moderate number of dental technicians in Romania are using CAD/ CAM systems in their clinical practice, as the large initial investment required for their purchasing is the main barrier for further implementation of this technology. [ABSTRACT FROM AUTHOR]

The aim of the present study is to evaluate the behavior of artificial teeth which support a porcelain-fused-to-metal (PFM) prosthetic reconstruction to mimic in vitro the movements of natural teeth under different simulated implantation degrees. A Frasaco typodont was used to this purpose and two different degrees of implantation were simulated. Non-contact vibration measurements of the samples were made using a laser Doppler vibrometer (LDV), and a continuous analogue voltage output of the LDV data was included in the study. [ABSTRACT FROM AUTHOR]

Introduction. The objective of this in-vitro study was to compare the accuracy, defined as trueness and precision, of an intraoral scanner and a cast scanner belonging to the same manufacturer (Dental Wings, Montreal, Canada). Materials and methods. An experimental model consisting of a die with a standard preparation for a porcelain fused to a metal crown was manufactured from a disk of polymethylmethacrylate resin, through CAD/CAM milling. The PMMA model was digitized by using an industrial CT in order to obtain the digital reference model. Afterwards, the resin model was scanned 15 times with each scanner, following manufacturer's instructions. In order to asses trueness, comparisons were performed with the digital reference model while, for precision, the first scan in the series was compared with the following scans. Results and disscusion. When the trueness of the included scanners was tested, the average deviation for the laboratory scanner was 9.85 μm and 20.85 μm, respectively, for the intraoral scanner. As for precision, the mean recorded deviations were 6.32 μm for the laboratory scanner and 17.18 μm for the intraoral scanner. For both fidelity and trueness, F and T tests demonstrate a statistically significant difference between the scanners. Conclusions. Within the limits of this study, we can state that a significant difference was observed between the accuracy displayed by the scanners tested in this study, mainly generated by the different capturing techniques used by each scanner. [ABSTRACT FROM AUTHOR]

Objective: The main goal of the present study is to compare two methods for evaluating the marginal fit of fixed prosthetic restorations. For this purpose we used a milled ceramic material, out of which we obtained class I inlays. The marginal gap was analyzed using micro CT and electronic microscopy. Materials and methods: After extraction of four caries-free mandibular first molars, first class inlay cavities were prepared. 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. For the second method SEM technology was used, and measurements were made at the occlusal limit of the cavities, between the restoration and the tooth in 50 microns steps. The data were compared with One-way ANOVA with Tukey's Multiple Comparison Test performed using 5.00 for Windows (GraphPad Prism 5.00 Software, San Diego, California USA). Results and discussion: For both methods we obtained clinical acceptable values of the marginal gap for the milled ceramic inlays. The null hypothesis was rejected. We obtained statistical significant differences of the measured gaps using the two above mentioned methods. Conclusions: Both evaluation methods are reliable for measuring the marginal gap of fixed prosthetic restorations, each method having specific indications, advantages and disadvantages. They offer indispensable information which lead to improvement of the restorative treatments. [ABSTRACT FROM AUTHOR]

Aims. This study was conducted to assess the knowledge and degree of acceptance of dental CAD/CAM systems among oral healtcare providers in the city of Cluj- Napoca, Romania. Materials and methods. A questionnarebased survey containing 23 questions was distributed by means of a web-based social platform to the dentists practising in the city of Cluj-Napoca. 103 valid questionnaires from oral healthcare physicians with more than one year experience in clinical practice were obtained. Descriptive statistical analysis was performed and results were expressed as number and percentage for each question. Results and discussion. A significant percentage of dentists asserted they have theoretical knowledge about this technology (85.4%), while only nine dentists (8.73%) currently use CAD/CAM technology in their clinical practice. However, over 75% of the surveyed subjects intend to use at least an intraoral digital scanner in the next 5 years. Most of the surveyed clinicians consider that their profession is not affected by the introduction of subtractive manufacturing systems, however the role of the dental technicians is diminished by the introduction of this technology. Conclusions. At present, a relatively small number of oral health providers are using CAD/CAM systems in their clinical practice, even most of them plan to use this technology in the near future. [ABSTRACT FROM AUTHOR]

Crown preparation and cementation are two critical parameters for the success of a prosthetic treatment. Marginal fit is very important because a large marginal opening allows plaque and oral liquids to penetrate, resulting in microleakage, caries and periodontal disease. The purpose of this study was to evaluate and compare the marginal fit of Cr-Ni metallic crowns made on molars, extracted because of orthodontic reasons. The freshly extracted teeth were kept in artificial saliva in order to reduce penetration of microorganisms and to simulate oral environment. The preparations were made with a 900 shoulder margin, rounded shoulder and without shoulder (tangent). Wax patterns were made using different techniques: simple and double captechnique, as well as ventil technique. Crowns were obtained using inox alloy. In vitro cementation with Ketac Cem was carried out after disinfection and drying. After cementation, samples were maintained for 24 hours at 37 in distilled water and then metalized with gold. The marginal gap was analyzed using scanning electronic microscopy in several points of each face of every prepared tooth. Data (results) were included in a statistical study. Measuring the internal fit of artificial crowns requires sectioning of specimens and makes it possible to obtain a small number of samples (1-2 per specimen) which means a limited number of measurements per specimen. Another problem consists in the reduced size of the samples after sectioning. The scanning technique enhances measurements of the marginal gap without sectioning and provides an objective evaluation of preparation and cementation techniques. [ABSTRACT FROM AUTHOR]

Introduction.In this study we aimed to investigate the vibrations of this system, because by identifying the parameters of the system we obtain a series of data that reflect the coupling of the tooth with the alveolar region, ie exactly the periodontium. Because the free response of the systems, the experimental results are not affected by the interaction between the vibrating system and the excitation system, we designed a series of measurement methods based on the free response. Physical measurement and quantification of dental mobility was performed using a Periotesttype device. The main objective was to design a system with which we can evaluate more than the relative score indicated by the periotest, taking into account that it is limited in the case of evaluating the dental support columns under fixed partial dentures.Materials and methods. Following the analysis of the possibilities and physical limitations of the clinical use of a periotest device, we concluded that in order to assess the change in the mechano-elastic properties of periodontal tissue, a more in-depth analysis method must be developed to allow a dynamic assessment of the clinical situation. Results and discussion. The introduction of the mechanical properties of the periodontal system to characterize the state of health or damage to the teeth of the periodontal disease in place of the system given by the Periotest type device provides information with physical sense that reflects the degree of the tooth coupling with the alveolar bone. Conclusions. From the numerical data obtained from the clinical measurements, a tendency of the decrease of the elastic constants corresponding to the periodontal tissue can be observed, directly proportional to the diminution of its support. [ABSTRACT FROM AUTHOR]

Background. Anxiety is widely known in dentistry. Even though it is a very recurrent issue, no protocol has yet been established that could be used for definite results. Aims. The aim was to review the literature in order to find effective strategies employed by dentists that could help patients to overcome their anxiety. Methods. A review of 24 articles on Pubmed platform using the terms: "dental anxiety", "physical activity", "sports" and "exercise" was conducted. We chose publications discussing the possible solutions for managing dental anxiety. Results. The solutions proposed in the scientific literature included: cognitive-behavioral therapy, relaxation techniques, premedication with sedative drugs (benzodiazepine), music distraction, hypnosis, acupuncture, inhalation sedation, aromatherapy with essential oils, parental presence/absence for children and audiovisual distraction. Conclusions. Cognitive-behavioral therapy seemed to be the most efficient method for patients to overcome dental anxiety. Repeated exposure to dental treatment increased the efficiency of the other strategies. [ABSTRACT FROM AUTHOR]