Conventional Dental Impressions vs. Impressions Reinforced with Rigid Mouthguards.

The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based, they have issues regarding their dimensional stability. In this respect, the present work proposes a new type of dental impression, which is reinforced with rigid mouthguards. The aim of the study is to test the performances of such new impressions by comparing them to conventional ones-from this critical point of view, of the dimensional stability. Three types of polymeric materials were considered for both types of impressions: alginate, condensation silicone, and addition silicone. In order to obtain the new type of impressions, a manufacturing technique was developed, comprising the following phases: (i) conventional impressions were made; (ii) a plaster model was duplicated, and 15 rigid mouthguards were obtained; (iii) they were inserted in the impression technique, with each mouthguard positioned on the cast before the high-consistency material was inserted in the tray and the practitioner took the impression; (iv) the mouthguard remained in the tray and the low-viscosity material was inserted over the mouthguard; (v) the impression was positioned on the model, and after the material hardened, the mouthguard-reinforced impression was analyzed. In the evaluation of the dimensional stability, rigorous statistical analysis was essential to discern the performance differences between conventional and mouthguard-reinforced dental impressions. Statistical analyses employed non-parametric Mann-Whitney U tests because of the non-normal distribution of the data. They indicated a statistically significant improvement in the dimensional stability of addition silicone impressions when reinforced with mouthguards (p < 0.05), showcasing superior performance over conventional methods. Conversely, alginate and condensation silicone reinforced impressions did not exhibit the same level of stability improvement, suggesting the need for further optimization of these materials. In conclusion, from the three considered elastomers, addition silicone was found to be the prime candidate for high-precision dental impressions, with the potential to improve their quality from conventional impressions by utilizing the proposed reinforcing technique.

The Impact of Latent Toxoplasma gondii Infection on Spontaneous Abortion History and Pregnancy Outcomes: A Large-Scale Study.

BACKGROUND: Toxoplasma gondii (TG), a zoonotic protozoan parasite, belongs to a group of TORCH infectious agents, which can cause severe damage to the fetus if a primary infection occurs during pregnancy. After primary infection, TG rests lifelong in human organisms causing a latent infection. Most studies have analyzed the consequences of acute, but not latent, TG infection. This study analyzed the impact of latent toxoplasmosis on spontaneous abortion history, pregnancy complication rate and neonatal outcome. METHODS: IgG and IgM anti-TG antibodies were tested in 806 pregnant women who were consulted at the Timisoara Clinical Emergency Hospital between 2008 and 2010. Demographic data, obstetrical history, and data about the pregnancy complications, birth and neonate were collected for each woman and comparisons between the groups, with and without latent TG infection, were made. RESULTS: This study did not show differences between groups regarding the history of spontaneous abortion (OR = 1.288, p = 0.333), cesarean section (OR = 1.021, p = 0.884), placental abruption (OR 0.995, p = 0.266), pregnancy-induced hypertension rate (OR 1.083, p = 0.846), secondary sex ratio (1.043, p = 0.776), 1' APGAR score at birth (p = 0.544), gestational age at birth (p = 0.491) or birth weight (p = 0.257). CONCLUSIONS: The observed differences between the rate of pregnancy complications in the two groups of pregnant women with and without latent infection with TG, did not reach a statistical significance.

Emerging Technologies for Dentin Caries Detection-A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed at assessing the diagnostic accuracy of emerging technologies, such as laser fluorescence (LF), transillumination, light-emitting diode devices, optical coherence tomography (OCT), alternating current impedance spectroscopy, fluorescence cameras (FC), photo-thermal radiometry, and modulated luminescence technology. In vivo and in vitro results of such non-ionizing, non-invasive, and non-destructive methods' effectiveness in non-cavitated dentin caries detection are sometimes ambiguous. Following the PRISMA guidelines, 34 relevant research articles published between 2011-2021 were selected. The risk of bias was assessed with a tool tailored for caries diagnostic studies, and subsequent quantitative uni- and bi-variate meta-analysis was carried out in separate sub-groups according to the investigated surface (occlusal/proximal) and study setting (in vivo/in vitro). In spite of the high heterogeneity across the review groups, in vitro studies on LF and FC proved a good diagnostic ability for the occlusal surface, with area under the curve (AUC) of 0.803 (11 studies) and 0.845 (five studies), respectively. OCT studies reported an outstanding performance with an overall AUC = 0.945 (four studies). Promising technologies, such as OCT or FC VistaProof, still need well-designed and well-powered studies to accrue experimental and clinical data for conclusive medical evidence, especially for the proximal surface. Registration: INPLASY202210097.

Toxicological Assessment of an Acrylic Removable Orthodontic Appliance Using 2D and 3D In Vitro Methods.

Malocclusion is a global health problem, mainly affecting children and adolescents. For this reason, orthodontic treatment must be, on the one hand, safe, non-toxic, and effective and, on the other hand, it must have the best possible esthetic profile. Thus, the use of orthodontic appliances is addressed to all age groups, including young children, for a long period of time, which is why their safety profile is a matter of real interest. For this reason, the purpose of the present study was to evaluate the safety and biocompatibility of an acrylic removable orthodontic appliance made of polymethylmethacrylate and stainless steel alloy made by our team of researchers. To verify the biocompatibility of the medical device, it was immersed in artificial saliva with three different pHs (3, 7, and 10) for a period of ten days. Subsequently, the three types of saliva were tested on human keratinocytes (HaCaT cell line) in terms of viability and modification of cell morphology. Finally, the use of 3D reconstructed human epidermis verified the cytotoxic and irritating potential of the medical device, thus providing relevant information regarding its biocompatibility. The results revealed that by maintaining the orthodontic device in the saliva there is no release of substances with a toxic effect on the human keratinocytes and on the 3D reconstructed human epidermis. There were also no significant changes in cell morphology. In conclusion, it is suggested that the acrylic removable appliance has a safety profile recommended for in vivo use.

Endodontic fillings evaluated using en face OCT, microCT and SEM.

OBJECTIVES: The goal of endodontic therapy is mechanically cleaning and shaping the root canal system, the removal of organic and inorganic debris followed by sealing with permanent filling materials. MATERIALS AND METHODS: Therefore, the aim of this in vitro study was to engage three imagistic methods: (i) en face (ef) time domain (TD) optical coherence tomography (OCT), (ii) micro-computed tomography (µCT), and (iii) scanning electron microscopy (SEM), in terms of their efficiency in assessing the quality of endodontic fillings. So far, is settled that efOCT images can identify defects∕voids in several of the investigated root canal fillings and identify gaps of 50 µm. RESULTS: The results delivered by µCT technology also showed several imperfections of the endodontic filling but also at the interfaces formed by the sealer and the root canal walls. SEM investigations highlights the complex form of the interface formed the endodontic filling material and the walls of the root canal, as well as shortcomings of the materials from several samples. Gaps of 50 µm are identified with efOCT. CONCLUSIONS: The net advantage of OCT technology, in respect to the other two technologies consists in its non-invasiveness. The OCT axial resolution is also sufficient to see the material gaps. Another advantage of efOCT investigations is that they allow real-time imaging of complex arrangement at the interfaces of the filling material with dentinal root.

Morphological aspects in remineralizing potential of Silver Diamine Fluoride.

OBJECTIVES: The purpose of this study was to demonstrate the efficacy of Silver Diamine Fluoride (SDF) antibacterial solution in penetrating the demineralized areas of enamel. MATERIALS AND METHODS: It was considered a group of four extracted teeth (with no color fading, fissures, decay, or demineralization). Each tooth was sectioned in two equal parts, in mesio-distal direction, using a dental handpiece and a special rounded, flat bur. Each specimen was demineralized, for one minute, with 45% orthophosphoric acid, on occlusal and proximal zones. The specimens were then washed and dried with water-air dental syringe. All the probes were inspected with an optical microscope and enamel thickness was digitally measured. Advantage Arrest (Elevate Oral Care, USA), which contains SDF, was applied on the previous demineralized zones. The penetration of the substance was visually inspected with the optical microscope and electronically measured. RESULTS: It was observed an improvement in remineralizing the white spots on enamel surfaces, the optical microscope being able to detect both demineralization and the penetration of SDF through enamel. CONCLUSIONS: Based on our in vitro study, SDF (Advantage Arrest) was capable to induce/increase enamel remineralization, through SDF penetration.

Micro-CT and optical microscopy imagistic investigations of root canal morphology.

Protecting the root's internal morphology is the first key toward the success of the endodontic treatment. Due to the vast diversity of endodontic space, it is difficult to visualize and to establish the shape and limits of the root canal, especially the morphology of apical area and lateral root canals. Optical microscopy is a classical imagistic investigation method, widely used along classical methods like radiographs that also offer limited information about root morphology and extension of decay. Micro-computed tomography (micro-CT), a modern imagistic investigation method can provide detailed three-dimensional reconstructions of root canal. Micro-CT is a non-invasive method that has the possibility to offer cross-sectional and axial images of the endodontic space. The success of root canal treatment is based on cleaning and shaping. Beyond these two procedures, sealing the endodontic space by respecting its limits is another prerequisite for long-term success of endodontic therapy. Micro-CT can perform three-dimensional reconstruction of the root canal, root canal filling and can provide accurate images of the endodontic space. The assessment of root morphology can be obtained through imagistic invasive optical microscopy and already mentioned non-invasive methods (micro-CT). The aim of this study is to illustrate and analyze the endodontic space, according to its diversity by using micro-CT, a non-invasive imagistic investigation method an also optical microscopy. The two techniques can also provide the extension of carries or demineralized substance on different levels of the root.