European Journal of Oral Sciences最新文献

Rheumatoid arthritis is a chronic autoimmune disease that can affect the temporomandibular joint (TMJ) and cause pain. Methotrexate is widely used to control disease progression, but its effects on pain mechanisms are not fully understood. This study evaluated the antinociceptive effects of methotrexate on pain behavior, Wnt/β-catenin pathway expression, and glial activation in the trigeminal nociceptive pathway in rats with TMJ arthritis. Eighteen male Wistar rats were assigned to one of three groups: control, arthritic, or arthritic treated with methotrexate. Arthritis was induced by intra-articular injection of methylated bovine serum albumin. Pain behavior, inflammation, and joint damage were assessed. Immunoexpression of Wnt/β-catenin components and c-Fos was analyzed in the trigeminal ganglion and subnucleus caudalis, along with microglial activation. Methotrexate-treated arthritic rats showed increased pain threshold, reduced facial pain behaviors, and decreased inflammatory infiltrates, along with lower levels of tumor necrosis factor-α and interleukin-17 in the joint compared to untreated arthritic rats. Methotrexate also reduced c-Fos, Wnt-10b, β-catenin, and glutamine synthetase expression in the trigeminal ganglion and attenuated microglial activation in the subnucleus caudalis. These results indicate that methotrexate produces antinociceptive effects by modulating Wnt/β-catenin signaling and reducing glial activation in the trigeminal nociceptive pathway in rats with TMJ arthritis.

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown aetiology, which is an oral potentially malignant disorder. Many investigators suggest that OLP may be a localized autoimmune response caused by cell-mediated autoimmunity to basal cells. However, it remains unclear whether allergens play a role in the pathogenesis of OLP. This study describes the expression of total IgE and specific IgE to six common antigens using the Uni-CAP system in healthy controls and OLP patients and investigates the IgG response to 14 food items to explore a possible association between OLP and a non-IgE mediated allergic reaction. Total IgE levels of the OLP patients were higher than seen in healthy controls. Two of 40 controls had IgE to house dust (HX2) compared to 8 of 40 patients with OLP; 2/40 controls had IgE to shrimp (F24) compared to 7/40 patients with OLP. Twenty-nine of 40 OLP patients were positive for IgG to 14 food types which was higher than the 20/40 seen in the control group. The findings indicate that OLP may be associated with hypersensitivity and food intolerance. Avoiding allergen exposure and administering appropriate desensitization treatments might facilitate the recovery of OLP.

This report presents the findings of a secondary analysis of the data from an RCT designed to compare salivary fluoride levels during 3 weeks of using 5000 or 1450-ppm fluoride toothpaste (n = 24/group). Following this trial phase, salivary fluoride monitoring continued for 2 weeks during which all 48 participants used 1450-ppm fluoride toothpaste in a wash-out phase. We investigated the temporal variability and longitudinal growth-based trajectories of salivary fluoride levels across study arms. During the trial phase, variability in the 5000-ppm arm exceeded that of the 1450-ppm arm. The best-fitting trajectories identified three clusters of participants following: low, medium or high salivary fluoride trajectories. Except for the ‘high’ cluster during the wash-out period, which featured only participants from the 5000-ppm trial arm, all clusters had participants from both trial arms. In conclusion, exploration of the variation and trajectories of salivary fluoride after 1450- and 5000-ppm fluoride toothpaste-use suggests non-constant responses to the initiation of and wash-out from the use of high-dosage fluoride toothpaste. This calls for the use of repeated period cross-over trial designs to investigate treatment effect heterogeneity. Reasons for and ways to minimize sources of individual variation in salivary fluoride levels are discussed.

This study evaluated the influence of femtosecond (fs) laser micromachining and hydrofluoric acid (HF)-etching on the surface roughness (Ra) and resin bond strength of restorative materials. The study used 120 rectangular-shaped specimens from four computer-aided design/manufacturing (CAD/CAM) blocks (lithium-disilicate glass-ceramic [LDS; e.max CAD], leucite-reinforced glass-ceramic [LGC; Empress CAD], zirconia-reinforced lithium-silicate [ZLS; Vita Suprinity], and polymer-infiltrated-ceramic-network [PICN; Vita Enamic]) and divided them into three subgroups based on the surface treatments applied: Control, HF-etching (HF), and fs-laser irradiation (FS). Surface roughness was measured using a surface profilometer. The surfaces were examined by a scanning electron microscope. A silane bonding agent was applied, and a self-adhesive dual-cure resin cement was bonded to the surfaces. The shear bond strength (SBS) test was conducted using a universal test device. FS-treated groups had higher Ra than HF-treated specimens. PICN showed higher Ra than other materials among the FS-treated groups. The HF-treated LDS showed the highest SBS. ZLS had the lowest SBS among the etched groups. Regardless of the material, the fs-laser treatment resulted in significantly higher SBS values than seen for controls. Fs-laser micromachining could be a promising alternative to conventional HF-etching, given its potential to uniformly roughen the bonding surface of CAD/CAM materials and improve resin bonding.

The aim of this study is to present a compound core manufacturing defect identified in a nickel–titanium (NiTi) instrument via fractographic analysis during additional retrospective analysis after dynamic cyclic fatigue resistance testing. This study raises awareness of core manufacturing defects and fosters the development of high-quality NiTi instruments without defects for clinical application. A scanning electron microscope with an acceleration voltage of 5 kV was used for fractographic analysis after cyclic fatigue testing. The fractographic analysis identified a compound core manufacturing defect, involving unmelted powder, and two interconnected failures. To the best of our knowledge, this is the first study to identify such compound core manufacturing defect in a NiTi instrument during fractographic analysis via scanning electron microscopy. The study underscores the need for detection and rectification of manufacturing defects, with methods such as X-ray computed tomography and hot isostatic pressing. The presence of core manufacturing defects in the NiTi instruments elevates the likelihood of premature clinical fracture, which may add to their inherent susceptibility to fracture in root canals due to cyclic fatigue and/or torsional stress.

This study investigated the influence of 10-methacryloyloxydecyl dihydrogen phosphate (MDP) agents and repeated saliva contamination on the microtensile bond strength (µTBS) of two self-adhesive resin cements (SARCs) bonded to dentin. Forty-eight sound human teeth were randomly divided into eight experimental groups, based on three factors: the type of SARC, the presence or absence of an MDP agent, and the presence or absence of multiple saliva exposures. The control group for each SARC received neither MDP agent nor multiple saliva contaminations. For each group, five teeth were sectioned to obtain 30–44 beams, followed by µTBS testing, fracture mode analysis, and scanning electron microscopy. Data were analyzed using one-way and two-way analysis of variance, Scheffé’s test, and Weibull statistics. Under uncontaminated conditions, the application of MDP agents was found to significantly enhance the bond strength of both SARCs. Saliva contamination significantly reduced µTBS, regardless of the cement used. However, when MDP agents were applied prior to bonding, µTBS values remained comparable to those of uncontaminated controls, even after multiple saliva exposures. These results support the use of MDP agents to maintain adhesive integrity in the presence of repeated salivary contaminations, offering greater reliability in adverse clinical environments.

Jaw–head movement coordination develops during adolescence. However, functional adjustments during this period remain poorly understood. This study aimed to characterize jaw and head movement adjustments in early adolescents and compare this to adults. Three-dimensional optical cameras captured jaw and head movements during maximum jaw opening–closing and chewing. Twenty (8 females, 12 males) adolescents (mean 13.5 yr, standard deviation [SD] 8 months) and 20 (9 females, 11 males) adults (mean 28.2 yr, SD 80 months) participated. Outcomes included jaw and head movement magnitudes, movement cycle time, time to first peak value, and initial phase. Functional data analysis and Wilcoxon rank-sum tests were employed. Adolescents showed larger head magnitude in jaw opening–closing and smaller jaw magnitude than did adults during chewing in the first movement cycle. Adolescents exhibited longer time to peak and time of first movement cycle during jaw opening–closing. During chewing, adolescents showed a longer initial phase, time to peak for consecutive cycles, and movement cycle time. For both age groups, the first cycle differed from consecutive cycles in jaw and head movement magnitudes and cycle times. Compared to adults, adolescents displayed pronounced spatiotemporal initial jaw–head movement adjustments during jaw function, particularly in the first movement cycle. Jaw–head coordination refines from early adolescence into adulthood.

This study aimed to explore trends in dental status and utilization of dental care services over time and to assess the relationship between dental service utilization and dental status among adult Danes aged 20+ years. A register-based cohort study linked individual-level information on dental services received, age, gender, municipality/region, highest completed education, socioeconomic position, income, and immigrant/descendant status for each calendar year in the period 1990–2021. Also included were data reported by dentists since 2001 on number of teeth present, number of teeth with decay, and number of teeth with fillings for 25-, 40-, and 65-year-old patients. About 58% of all adults had used the dental health care system in 2021, less than that seen in previous decades. Non-users were younger, male, had lower income, lower education, lower socioeconomic position, and were immigrants or descendants. Dental attendance has substantially reduced over time among age groups younger than 70 years but increased among the older age groups. Considerable improvements in dental health were noted, with greater tooth retention, fewer caries, and fewer filled teeth in the indicator age groups since 2001. The findings suggest a need for redistribution of resources for oral health care to target vulnerable subgroups carrying larger disease burdens.

This in vitro study evaluated fluoride release and Streptococcus mutans biofilm formation on four types of dental sealants: a giomer, resin-modified glass ionomer, compomer, and a fluoride-free composite (control). Discs were prepared as per the manufacturers’ instructions, and they were placed in tubes containing ultrapure water. Fluoride release was measured after 2, 7, and 30 days using ion chromatography, and biofilm formation was analyzed via scanning electron microscopy (SEM). A repeated-measures linear mixed model with log transformation and Bonferroni-corrected post-hoc tests was applied. The resin-modified glass ionomer showed the highest fluoride release, followed by the giomer, with increasing values over time. Compomer and the fluoride-free composite exhibited low, stable fluoride levels. SEM confirmed S. mutans biofilm on all materials. These findings highlight distinct fluoride release profiles and suggest that materials with higher fluoride release may offer improved long-term protection against cariogenic biofilm formation.

This study assesses soft tissue compensations on the left and right sides of the face in individuals with apparent facial asymmetry and compares perception differences between the general population and orthodontists. This prospective study was conducted on 20 patients (aged 18–30 years) with apparent facial asymmetry. Skeletal asymmetry was evaluated using posteroanterior cephalograms, measuring deviations of the zygomatic suture, zygomatic arch, nasal cavity, antegonion (Ag), and menton (Me) from the midsagittal reference line. Corresponding soft tissue deviations were clinically measured. Perception of facial asymmetry was assessed using a visual analog scale (VAS) based on frontal photographs rated by 20 orthodontists and 20 members of the general population. Patients were categorized into four groups based on chin asymmetry (1–2 mm, 3–4 mm, 5–7 mm, > 7 mm). The findings showed that the skeletal asymmetry was greater than soft tissue asymmetry, indicating soft tissue compensation, particularly at Ag and Me. Orthodontists rated facial asymmetry more critically, but for chin shifts > 5 mm, both groups had similar perceptions. It was concluded that soft tissue compensations, especially in the lower face, help to mask skeletal asymmetry. Orthodontists detect subtle facial asymmetries better than laypersons, though larger asymmetries (> 5 mm) are universally noticeable.