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Purpose: We investigated the effect of deep learning reconstruction (DLR) plus single-energy metal artifact reduction (SEMAR) on neck CT in patients with dental metals, comparing it with DLR and with hybrid iterative reconstruction (Hybrid IR)–SEMAR. Methods: In this retrospective study, 32 patients (25 men, 7 women; mean age: 63 ± 15 years) with dental metals underwent contrast-enhanced CT of the oral and oropharyngeal regions. Axial images were reconstructed using DLR, Hybrid IR–SEMAR, and DLR-SEMAR. In quantitative analyses, degrees of image noise and artifacts were evaluated. In one-by-one qualitative analyses, 2 radiologists evaluated metal artifacts, the depiction of structures, and noise on five-point scales. In side-by-side qualitative analyses, artifacts and overall image quality were evaluated by comparing Hybrid IR–SEMAR with DLR-SEMAR. Results: Artifacts were significantly less with DLR-SEMAR than with DLR in quantitative (P <.001) and one-by-one qualitative (P <.001) analyses, which resulted in significantly better depiction of most structures (P <.004). Artifacts in side-by-side analysis and image noise in quantitative and one-by-one qualitative analyses (P <.001) were significantly less with DLR-SEMAR than with Hybrid IR–SEMAR, resulting in significantly better overall quality of DLR-SEMAR. Conclusions: Compared with DLR and Hybrid IR–SEMAR, DLR-SEMAR provided significantly better supra hyoid neck CT images in patients with dental metals. [ABSTRACT FROM AUTHOR]

Objectives: When dentists adjust prostheses at the dental chairside, particulate matter (PM) from the dental material is dispersed. Little is known about the effective use of an extraoral vacuum (EOV) in preventing PM dispersal. This study aimed to evaluate the effective use of an EOV in preventing the dispersal of metal PM in dental offices. Methods: The following experimental conditions were planned: the distance from the EOV to the metallic materials (50, 100, 150, and 200 mm), the horizontal angle between the long axis of the micromotor handpiece and EOV (0°, 45°, and 90°), and the operating time of the EOV (during grinding, during grinding and 1 min thereafter, during grinding and the preceding 1 min, 1 min before and after grinding, and during grinding). Carborundum and silicone points were used for grinding and PM dispersal. Diameters (0.3, 0.5, 1.0, and 3.0 μm) were measured using a laser particle counter. Results: Depending on the instrument used to grind, there were undetectable PMs of different diameters (Carborundum point: 0.3 and 0.5 μm, Silicone point: 0.3 μm). PMNs were reduced as the distance from the EOV to metal materials decreased. Operating the EOV before grinding along the long axis of the micromotor handpiece was effective in reducing the PMNs. Conclusion: PMNs dispersed when grinding metals were effectively reduced by positioning the EOV closer to the grinding surface (within 150 mm) along the long axis of the micromotor handpiece and operating the EOV before grinding. [ABSTRACT FROM AUTHOR]

Metals and their alloys have been applied widely in the field of stomatology due to their good properties. However, as the oral environment and oral therapeutic schemes are complex, most dental metals have the problems of low biocompatibility and insufficient efficacy. With the development of nanotechnology, nanomodification has provided new opportunities for the surface modification of dental metals. Materials with nanoscale morphology and nanocoatings endow dental metal surfaces with nanoproperties that stimulate and guide various biological processes, providing potential solutions to clinical problems. This review characterizes current applications of nanotechnology for dental metal surface modification, with discussion of the resulting materials’ biocompatibility, interactions with cells and antibacterial activity. We also summarize the available information on the main preparation programs and key parameters of surface nanomodification, with discussion of the special advantages and difficulties associated with the nanomodification of metals employed in the oral cavity. We provide suggestions and references for improvement of the surface performance of dental metals and facilitation of their broad application.

The usefulness of dental approaches, such as oral management, has gained recognition among patients treated for head and neck cancer. In particular, oral management plays a very important role before, during, and after treatment in patients undergoing radiotherapy, chemotherapy, or a combination of both. However, specialized dentistry knowledge and techniques that are useful for patients undergoing radiotherapy for head and neck cancer have yet to be reported. Therefore, in this review article, our aim is to introduce dental approaches in radiotherapy for patients with head and neck cancer that have been developed and are currently being used at our institute.

The number of patients with metal allergies has increased recently, and patch testing is useful for investigating such patients. However, the efficacy of restoration removal in patients with oral metal allergies is disputed. This study aimed to investigate the relationships between oral symptoms and metal allergies. We conducted a retrospective analysis of 60 patients with oral symptoms. The most common oral symptom was an abnormal oral sensation. Thirty‐eight percent of the patients exhibited positive allergic reactions to one or more metal. Nickel was the metal allergen that produced positive reactions most frequently. Of the seven patients whose restorations were removed, complete and partial remission were achieved in one and two patients, respectively. Interestingly, metal alloy removal was effective in 33% (n = 1) of the positive patch test group and 50% (n = 2) of the non‐positive patch test group. Our results demonstrated the difficulty of predicting the efficacy of restoration removal at ameliorating oral metal allergies based on patch testing alone. [ABSTRACT FROM AUTHOR]

Summary The usefulness of dental approaches, such as oral management, has gained recognition among patients treated for head and neck cancer. In particular, oral management plays a very important role before, during, and after treatment in patients undergoing radiotherapy, chemotherapy, or a combination of both. However, specialized dentistry knowledge and techniques that are useful for patients undergoing radiotherapy for head and neck cancer have yet to be reported. Therefore, in this review article, our aim is to introduce dental approaches in radiotherapy for patients with head and neck cancer that have been developed and are currently being used at our institute. [ABSTRACT FROM AUTHOR]

Enhancement of the biological and mechanical properties of dental metals is important for accommodation with therapeutic schemes in different stomatological disciplines. Nanocoatings based on graphene family nanomaterials (GFNs) improve the topological structure and physicochemical properties of metal surfaces, endowing them with new properties while maintaining inherent mechanical properties. Nano-composite coatings, composed of GFNs with one or more type of polymer, metal, oxide, and inorganic nonmetallic compound, offer more matching modification schemes to meet multifunctional oral treatment requirements (e.g., anti-bacterial and anti-corrosive activity, osteogenesis and angiogenesis). This review describes recent progress in the development of GFN composite nanocoatings for the modification of dental metals, focus on biological effects in clinical settings. Underlying molecular mechanisms, critical modification schemes, and technical innovation in preparation methods are also discussed. The key parameters of GFN composite nanocoating surface modification are summarized according to effects on cellular responses and antibacterial activity. This review provides a theoretical reference for the optimization of the biological effects and application of GFN composite nanocoatings for dental metals, and the promotion of the environmentally friendly large-scale production of high-quality multifunctional GFN-based nanocoatings in the field of oral science., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Contact allergy to dental materials is poorly understood; clinical manifestations are heterogeneous. Objective: To analyse positive patch test reactions to metals (as their alloys or salts) used in dentistry together with clinical symptoms and possible relevance to dental fillings. Methods: We retrospectively analysed 206 patients who underwent patch testing with metals used in dentistry because of suspected contact allergy to them. Results: Twenty-eight of 206 patients had positive patch test reactions to metals used in dentistry. The number of positive patch test reactions was highest for gold sodium thiosulfate, palladium chloride, and nickel sulfate ( n = 10, respectively), followed by amalgam, ammoniated mercury, and cobalt chloride ( n = 4, respectively) and amalgam-mixed metals (including copper, tin, zinc, and silicon), and ammonium tetrachloroplatinate ( n = 1). Only 14 (7%) of 206 patients had a clinically relevant contact allergy with conditions of the oral mucosa ( n = 7 with lichen planus and n = 7 with stomatitis) and positive patch test reactions to dental metals containing the suspected allergen. Improvement of symptoms was assessed in one patient with amalgam contact allergy 2 weeks after removal of dental fillings. Conclusions: Clinically relevant contact allergies to dental metals are infrequent. Gold sodium thiosulfate and palladium chloride presented the most frequent contact allergens. [ABSTRACT FROM AUTHOR]

Summary: Controlling the transmission of infectious diseases by impressions, metals and dental casts in dental hospitals remains a challenge. Current disinfection methods have various drawbacks. This study introduced and provided a preliminary evaluation of the feasibility of using ultrasonically nebulised, electrolysed oxidising water (UNEOW) as a new infection control programme. UNEOW was produced from freshly generated electrolysed oxidising water (EOW). Samples of impressions, titanium and gypsum were subjected to the following treatments: (1) immersion in 1% sodium hypochlorite for 10min; (2) immersion in EOW for 10min; (3) exposure to UNEOW for 15, 30 and 45min; (4) no disinfection (control). Bactericidal efficacy was examined using Staphylococcus aureus and Bacillus subtilis var. niger spores as indicators. Dimensional accuracy, surface quality, and effect of corrosion were also evaluated for the different samples. Results showed that except for B. subtilis var. niger spores on gypsum casts, the bacterial reduction log10 values after 30–45min treatment with UNEOW were all above 4. The impression dimensional changes showed no difference between control and UNEOW groups, but both were significantly lower than the EOW and sodium hypochlorite groups (P <0.05). The same was true for the surface quality of impressions and gypsum casts. No assessable corrosion was found on the titanium surface after a 45min treatment with UNEOW. The findings indicated that use of UNEOW is a feasible and promising approach for controlling the transmission of infectious diseases by impressions, gypsum casts and denture metals in dental facilities. [Copyright &y& Elsevier]

The article discusses the advantages of using titanium as a dental metal. It states that titanium has been used as a substitute for Au-Ag-Pd alloy due to its corrosion resistance and biocompatibility, however, it is not recommended in clinical dentistry due to its complex process. It notes the discovery of the dentists of new exclusive investment materials and casting methods to accurately develop and cast titanium which have improved to the level of clinical application.

The article presents a clinical study on atopic dermatitis (AD) clinical development through the dental metal removal in Japan. The dental restorations that contained lymphocyte stimulation test (LST)-positive metals are removed from patients with refractory AD. The article concludes that through dental metal removal improves clinical recalcitrant lesions and play significant role in the pathogenesis of refractory AD.

This study was conducted to clarify the influence of the copper surface oxidation and reduction on the shear-bond strength with functional monomers. Unheated copper specimens (UH; n = 88) were wet-ground. Three-quarters of the UH were then heated (HT). Two-thirds of the HT was then immersed in a hydrochloric acid solution (AC). Half of the AC was then reheated (RH). Each group was further divided into two groups (n = 11), which were primed by either 6-methacryloyloxyhexyl 2-thiouracil-5-carboxylate (MTU-6) or 10-methacryloyloxydecyl dihydrogen phosphate (MDP). The shear-bond strength tests were used for bonding with an acrylic resin. The surface roughness values and chemical states of the four groups were analyzed using a confocal scanning laser microscope and X-ray photoelectron spectroscopy (XPS). The shear-bond strengths of HT and RH were the lowest in the MTU-6-primed groups. The result of AC was significantly lower than others in the MDP-primed groups. The XPS results showed that the surfaces of UH and AC consisted of Cu2O and Cu. The surface changed to CuO upon heating. The presence or absence of copper-oxide films showed the opposite trends in the effectiveness of MTU-6 and MDP to improve bond strength. The results could elucidate the effects of functional monomers on copper-oxide films. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: This paper demonstrates a simple method using sacrificial protection for preventing the corrosion of dental metals. Methods: Dental metals are directly connected or/and wound with a pure commercial aluminum/zinc wire/plate with high ionization tendency, before their immersion into oxidizing functional water. Conclusion: Dental materials such as Co–Cr alloy wires, stainless steel, and Au–Ag–Pd alloys did not corrode when this method was used. Thus, this method is very simple and effective for preventing corrosion of dental metals during disinfection using functional water. [Copyright &y& Elsevier]

The aim of this study was to clarify the influence of the copper surfaces changed from Cu or Cu2O to CuO on the bonding strength of resin with organic sulfur compounds. The disk-shaped specimens (n = 44) of copper were wet-ground. Half of the specimens were heated at 400 °C for 4 min in an electric furnace (HT: heated). Half of the specimens were not heated (UH: unheated). The specimens were further divided into two groups. Each group was primed by 6-methacryloyloxyhexyl 2-thiouracil-5-carboxylate (MTU-6) or unprimed (n = 11). A statistical analysis of the results of shear bond strength testing was performed, and the failure mode of the bonded areas was classified with an optical microscope. Two types of specimen surface (UH or HT) were analyzed chemically using X-ray photoelectron spectroscopy (XPS). When primed with MTU-6, unheated Cu (28.3 MPa) showed greater bond strength than heated (19.1 MPa). When unprimed, heated Cu (4.1 MPa) showed greater bond strength than unheated (2.3 MPa). The results of the debonded surfaces observation showed that only the UH-MTU-6 group demonstrated a combination of adhesive and cohesive failures in all specimens. The XPS results showed that the surface of copper changed from Cu or Cu2O to CuO when HT. These results confirmed that it is necessary to take care of the copper oxide contained in noble metal alloys when using organic sulfur compounds for adhesion. [ABSTRACT FROM AUTHOR]