European Journal of Oral Sciences最新文献

The study aimed to investigate the influence of H₂O₂-based and H₂O₂-free in-office bleaching on the surface and mechanical attributes of CAD/CAM composite blocks. CAD/CAM composite blocks from five different composite materials (CC1, CC2, CC3, CC4, and CC5) were randomly divided into two groups according to bleaching application (H₂O₂-based and H₂O₂-free). The surface topography, morphology, nanohardness, elastic modulus, flexural strength, and fracture toughness were measured. A paired and unpaired sample t-tests gauged the effect of pre- and post-bleaching on the substrates. The estimated mean differences (before-after bleaching) suggested an increase in surface roughness for two materials CC2 and CC4, and a significant decrease in nanohardness for material CC4 and in elastic modulus for materials CC2 and CC4 with H₂O₂-based bleaching, whereas H₂O₂-free bleaching resulted in changes compatible with no change in these properties. Flexural strength and fracture toughness showed no evidence of changes, irrespective of the bleaching gel used. Scanning electron microscopic analysis revealed erosive effects and micropore formation due to H₂O₂-based bleaching. H₂O₂-based bleaching deteriorates the surface of CAD/CAM composite materials while H₂O₂-free bleaching gel had an insignificant effect on both surface and bulk properties. The clinician should carefully evaluate the potential effects of H₂O₂-based bleaching on the surface properties of CAD/CAM composites.

Dental pulp inflammation is a common and significant factor related to poor dental prognosis. Current treatment strategies primarily concentrate on managing the inflammatory response, with specific targets for intervention still under investigation. Triggering receptors expressed on myeloid cells (TREMs) are a group of receptor molecules extensively present on myeloid cell surfaces, crucial in the regulation of inflammatory process. Our analysis of transcriptomic sequencing data from clinical pulp samples of dataset GSE77459 and animal models revealed up-regulation of Trem1 during pulpitis. Administration of the Trem1-blocking peptide LP17 led to lower (more than 1-fold) levels of several pro-inflammatory factors and inhibition of M1 macrophage polarization both in vivo and in vitro. This study of the expression patterns and functions of Trem1 in the development of dental pulp inflammation provides novel insights into the therapeutic strategies for clinical pulpitis.

This study evaluated the effect of solutions containing aminomethacrylate copolymer (AA) and sodium fluoride (F; 225 ppm F⁻) or fluoride plus stannous chloride (FSn; 225 ppm F⁻, 800 ppm Sn²⁺) against enamel and dentin erosion/abrasion. Solutions F, FSn, AA, F+AA, FSn+AA, and deionized water as negative control were tested. Bovine enamel and dentin specimens (n = 13/solution/substrate) underwent a set of erosion-abrasion cycles (0.3% citric acid [5 min, 4×/day], human saliva [1 h, 4×/day], brushing [15 s, 2×/day], and treatments [2 min, 2×/day]) for each of five days. Initial enamel erosion was evaluated using Knoop microhardness after the first and second acid challenge on day 1, and surface loss with profilometry after day 5. KOH-soluble fluoride was assessed. Data were analyzed with ANOVA/Tukey tests. The combination of fluoride and AA resulted in higher protection against enamel erosion, whereas this was not the case for the combination of AA and FSn. All treatments protected against enamel and dentin loss. The lowest surface loss values were observed with F+AA and FSn+AA. The polymer did not significantly influence the KOH-soluble fluoride formation on enamel/dentin specimens. The aminomethacrylate copolymer effectively enhanced the efficacy of sodium fluoride against initial erosion and improved the control of enamel and dentin wear of F and FSn solutions.

This study aimed to evaluate the effects of the estrogen depression during orthodontic tooth movement on alveolar bone microarchitecture and periodontal ligament. Female Wistar rats were divided into two groups, one consisting of non-ovariectomized animals subjected to orthodontic tooth movement, and one comprising ovariectomized animals subjected to orthodontic tooth movement. Micro-CT assessment of bone volume to total volume (BV/TV), total porosity, trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp) in the alveolar bone of the orthodontically moved tooth was performed. Histomorphometric analyses were made in the periodontal ligament, and immunoexpression of RANK, RANKL, OPG, and TUNEL were quantified. Orthodontic tooth movement in the group of ovariectomized rats was faster than in non-ovariectomized animals. The alveolar bone area showed lower values of BV/TV and trabecular thickness, and higher bone porosity and trabeculae numbers in the ovariectomized rats. Histological analyses in the ovariectomized group revealed an increase in collagen fibers in the periodontal ligament. The apoptotic cell counts in the periodontal ligament were higher in the group of ovariectomized rats than in the sham-operated rats. Ovariectomy resulted in an increase in tooth movement and alteration of the alveolar bone microstructure in the first 7 day of orthodontic tooth movement, and in the presence of apoptotic cells in the periodontal ligament.

This study evaluated the changes in surface properties of three resin-based restorative materials after two laser-assisted, in-office tooth bleaching protocols using erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) or diode (980 nm) lasers. A nanohybrid composite (Enamel Plus HRi), a Bis-GMA-free composite (Enamel Plus HRi Bio Function), and a resin-matrix CAD-CAM ceramic (Shofu Block HC) were tested. Forty specimens for each material were prepared and divided into four groups (n = 10/group). The control specimens did not undergo any bleaching treatment, whereas group 2 received bleaching with 40% hydrogen peroxide (H₂O₂), while groups 3 and 4 underwent the same bleaching procedure with the use of diode (980 nm) or Er,Cr:YSGG lasers, respectively. Surface microhardness and roughness measurements were conducted using a Vickers tester and an optical profilometer. Microhardness was lower in bleached specimens, with the nanohybrid composite exhibiting the largest difference from the no bleaching group. For the Bis-GMA-free composite the microhardness difference between no bleaching and laser-assisted bleaching were smaller than seen for the conventional bleaching technique. Surface roughness was higher in bleached specimens, with nanohybrid composite showing the largest differences from the control specimens. The examined laser-assisted tooth bleaching protocols were found not to impact surface microhardness and roughness of the tested resin-based specimens and they are deemed suitable for clinical use.

The aim of this study was to examine the expression of programmed death-ligand 1 (PD-L1) and of T cell immunoglobulin and mucin domain-containing protein (TIM3) in oral epithelial dysplasia and head and neck squamous cell carcinoma (HNSCC). Mouse HNSCC was induced with 4-nitroquinoline-1 oxide (4NQO). Oral epithelial dysplastic lesions, carcinoma in situ and HNSCC lesions were stained with anti-PD-L1 and TIM3 antibodies. The expression of PD-L1 and TIM3 in tumor cells and immune cells was semiquantitatively measured and compared. In parallel, human dysplasia and HNSCC were stained with anti-PD-L1 and anti-TIM3. The expression pattern of PD-L1⁺ and TIM3⁺ cells was further compared. In human and mouse samples both PD-L1 and TIM3 were found to be expressed in neoplastic and immune cells in HNSCC, but not in dysplasia. There was no significant difference in PD-L1 and TIM3 expression between metastatic and nonmetastatic HNSCC. We conclude that the 4NQO-induced mouse HNSCC model may be an excellent preclinical model for immune checkpoint therapy.

This study aimed to investigate the relationship between epigenetic mechanisms and oral mucositis (OM) in paediatric patients with acute lymphoblastic leukaemia. Oral cells were collected from 76 participants, including 15 healthy individuals, 10 patients with acute lymphoblastic leukaemia but without a history of OM and 51 acute lymphoblastic leukaemia patients with a history of OM (35 with active OM and 16 who had recovered from OM). Global DNA methylation in the miR-9-1 and miR-9-3 genes was performed. Seven polymorphisms rs1801131, rs1801133 (MTHFR), rs2228611 (DNMT1), rs7590760, rs1550117 (DNMT3A), rs6087990, rs2424913 (DNMT3B) were genotyped and an analysis of association with global DNA methylation was performed. The global methylation levels were lower in cancer patients recovered from OM than in the other groups. A higher frequency of unmethylated profile for miR-9-1 and partially methylated profile for miR-9-3 was observed in cancer patients regardless of OM history compared to healthy patients. The GG genotype of the rs2228611 (DNMT1) polymorphism was associated with higher levels of global methylation in cancer patients irrespective of OM. It was concluded that global methylation is associated with mucosal recovery. The effect of DNMT1 genotype on the global DNA methylation profile, as well as the methylation profile of miR-9-1 and miR-9-3 in cancer patients is independent of OM.

Torture victims struggling with post-traumatic stress often experience elements in the dental treatment situation that may trigger trauma-related reactions. The aim of the study was to explore intervention strategies that will enable dental health workers to adapt dental treatment to the needs of torture survivors. Exploratory interviews were conducted with 10 torture-exposed resettled refugees with dental treatment experience in Norway. The data was analyzed using qualitative content analysis, which suggested that to minimize trauma-reactions, dental personnel should focus on creating a safe therapeutic space and strengthening the patient's sense of control. Four main categories of clinical advice were proposed: (i) Acquire knowledge about psychology, consequences of torture, cultural differences, trauma-informed care, and the patients’ individual needs; (ii) Recognize the trigger-potential of busyness or delays; (iii) Avoid surprises, such as sudden moves or actions and explore triggers individually, but make sure not to evoke images of interrogation, and; (iv) Provide overview both with respect to visibility in the clinical room, and to predictability regarding the dental treatment. Although undergoing dental treatment may be challenging for torture-exposed individuals, it is possible to reduce the predicaments considerably by making feasible adaptions to the treatment and adopting a trauma-informed approach.