Journal of oral science最新文献

Purpose: This study examined the association between oral health and nutritional intake among older denture wearers.

Methods: Oral health parameters were evaluated in 114 denture wearers, including the number of remaining teeth (<20 or ≥20), posterior occlusal support (Eichner classification A1-B3 or B4-C3), objective masticatory assessment (glucose concentration: <100 or ≥100 mg/dL), subjective masticatory assessment (self-reported masticatory problems), and occlusal force (<500 or ≥500 N). Nutritional intake was assessed using a brief self-administered diet history questionnaire. Differences in nutritional intake according to oral health parameters were assessed using multiple regression analysis.

Results: Fewer remaining teeth were associated with higher total fat (β = 0.207, P = 0.038) and plant fat (β = 0.242, P = 0.017) intakes, and with lower carbohydrate (β = -0.264, P = 0.026) and cereal (β = -0.320, P = 0.002) intakes. The presence of masticatory problems and absence of posterior occlusal support were associated with lower intakes of plant protein (β = -0.311, P = 0.002) and meat (β = -0.232, P = 0.022), respectively.

Conclusion: Among older denture wearers, denture design-related factors, such as the number of remaining teeth and posterior occlusal support, were associated with more nutritional intake items than oral function-related parameters.

Purpose: Cementum is a specialized calcified tissue produced by cementoblasts, which play a key role in periodontal regeneration. Enamel matrix derivative (EMD) is an agent currently employed for treatment of periodontal disease, although its molecular action mechanism remains unclear. The present study aimed to investigate the effects of EMD on cementoblast differentiation and the involvement of Wnt/β-catenin signaling in human periodontal ligament (hPDL) cells.

Methods: Primary hPDL cells were treated with EMD, and the expression of cementum-related markers was evaluated. The role of Wnt/β-catenin signaling was assessed using IWP-2, a Wnt inhibitor. A luciferase reporter assay was conducted to identify regulatory elements within the cementum protein 1 (CEMP1) promoter.

Results: EMD upregulated the expression of CEMP1 and cementum attachment protein. This effect was attenuated by IWP-2, indicating Wnt/β-catenin involvement. A T-cell factor binding site was identified within the CEMP1 promoter. EMD increased the expression of osterix and runt-related transcription factor 2 (Runx2) slightly, but decreased the levels of osteocalcin and osteopontin. No mineralization enhancement was observed based on alkaline phosphatase activity and Alizarin Red S stainingConclusion: EMD promotes early-stage cementoblast differentiation via Wnt/β-catenin signaling but has limited effects on late-stage maturation, offering new insights into the regenerative potential of EMD for periodontal therapy.

Purpose: To investigate the surface roughness (Ra), shear bond strength (SBS), and Vickers hardness number (VHN) of additive manufactured interim resins manufactured through different vat polymerization techniques.

Methods: Samples were divided into four groups; additive manufacturing technology (Stereolithography:S-FL; Digital light processing:D-AS; Liquid crystal display:L-PH) and subtractive manufacturing technology (Polymethylmethacrylate: MP) (n = 10). After polishing, the Ra values were measured and resin material was then applied. Following thermocycling, SBS tests and VHN tests were carried out. The obtained data were evaluated using one-way analysis of variance (ANOVA) (a = 0.05).

Results: Significant differences were observed between the groups for SBS (P = 0.02) and VHN (P < 0.001), whereas the Ra values were not statistically significant (P = 0.148). D-AS and L-PH had higher and similar SBS (P = 1.000) while MP had statistically lower SBS. D-AS demonstrated higher VHN than all groups (P < 0.001) with the exception of S-FL (P = 0.831). MP had lower VHN than all groups (P < 0.01) other than L-PH (P = 0.143).

Conclusion: All fabrication methods had clinically acceptable SBS values, L-PH and D-AS had higher results. D-AS demonstrated superiority in terms of VHN, all groups exhibited comparable Ra values.

Purpose: The impact of bone regeneration using bone graft materials on orthodontic tooth movement (OTM) remains unclear. This study was designed to histologically and biologically evaluate the influence of bone graft materials treated with a biosilane coupling agent on early bone formation and their effect on OTM.

Methods: Maxillary first molars of 4-week-old male Wistar rats were extracted, followed by alveolar bone regeneration using either carbonate apatite (Cytrans granules; Cyt) or biosilane-treated Cytrans (DI6M-Cyt). After 2 weeks, nickel-titanium (Ni-Ti) closed-coil springs were applied to exert mesial traction on the second molars, inducing OTM for 14 or 28 days. Bone formation characteristics and tooth movement patterns were evaluated via micro-computed tomography (micro-CT), histological analysis (hematoxylin and eosin [H&E] and tartrate-resistant acid phosphatase [TRAP] staining), and nanoindentation testing.

Results: Initial bone formation was noted in the DI6M-Cyt group relative to the untreated group, the rigidity of the newly formed bone approaching that of natural bone, thus inhibiting aberrant tooth movement following OTM. Furthermore, osteoclast activity was appropriately regulated, maintaining balanced bone remodeling.

Conclusion: These findings indicate that biosilane-treated bone graft materials enhance bone regeneration and that the newly formed bone does not impede OTM.

Purpose: To evaluate the effect of die spacer thickness on the fit and load to failure of cantilever resin-bonded fixed dental prostheses (RBFDPs).

Methods: Two identical maxillary RBFDPs with a retainer on the canine were designed to replace a lateral incisor. One design involved a closely fitting retainer with no die spacer (NDS), and the other included an 80-µm die spacer (DS). A total of 10 RBFDPs were produced for each group by selective laser melting. To simulate a natural canine abutment, lithium disilicate abutments were fabricated digitally. After bonding the RBFDP with an adhesive resin luting agent, the marginal fit was measured, and the specimens were then loaded until failure of the luting agent.

Results: The mean marginal fit in the NDS and DS groups was 79.1 µm and 75.7 µm, respectively, and the corresponding mean maximum load to failure was 272.8 N and 254.7 N, respectively. The inter-group differences in these values were not significant.

Conclusion: The inclusion of a RBFDP die spacer had no effect on the marginal fit and maximum load to failure. In addition, the die spacer had no significant effect on the pattern of resin luting agent failure.

Purpose: This study evaluated how the formation of various types of precipitates affects the accuracy of electronic apex locators in determining the working length.

Methods: Two hundred and forty extracted human maxillary incisors were selected. A total of eight groups were used: four groups (n = 30) for the application of different irrigants; saline, sodium hypochlorite (5.25% NaOCl), chlorhexidine (2% CHX) and ethylenediaminetetraacetic acid (EDTA) (17% EDTA), and four groups (n = 30) for the formation of precipitates; orange-brown (2% CHX + 5.25% NaOCl), orange-white (2% CHX + 0.16% NaOCl), white milky (2% CHX + 17% EDTA), salt (2% CHX + saline). Electronic working length was determined by two different electronic apex locators.

Results: The success rate of the 5.25% NaOCl group was significantly higher than that of the white milky precipitate group. The electronic apex locators were highly effective in identifying working length, but the success rate of both devices declined due to the production of a white milky precipitate.

Conclusion: The study emphasizes the importance of selecting appropriate irrigation protocols for optimal treatment outcomes, as the chemical interactions between solutions and precipitates significantly influence electronic apex locator measurements, highlighting the need for careful consideration of irrigant compatibility.

Purpose: This laboratory-based study evaluated the effects of sintering protocols, yttria content, and zirconia thickness on the optical properties of monolithic zirconia.

Methods: Three partially stabilized zirconia (PSZ) materials, one monolayer (HT) and two multilayer (GE, FX) samples, with thicknesses of 0.5-1.5 mm were tested under conventional and speed sintering protocols. Translucency parameter (TP), color difference (ΔE₀₀), and spectral reflectance were measured using a spectrophotometer against standardized black and white backgrounds. Statistical analyses were performed using a one-way analysis of variance, Tukey's post-hoc tests, and correlation analysis.

Results: The TP values decreased with increasing zirconia thickness; significant differences were observed between the sintering protocols. Speed sintering resulted in lower transparency in certain materials, particularly GE. Conversely, HT exhibited consistent optical properties across the sintering protocols. The ΔE₀₀ values for multilayer zirconia exceeded clinically acceptable thresholds, with greater variations observed for thicker specimens. Spectral reflectance curves were minimally influenced by the sintering protocol and thickness for monolayer zirconia, whereas they showed significant variations for multilayer zirconia.

Conclusion: The results indicate that sintering protocols and material composition significantly influence the optical properties of zirconia, underscoring the necessity of optimizing processing conditions to enhance both esthetic and functional performance in clinical applications.

Purpose: Oral hygiene is mainly maintained by mechanical plaque removal, but this is often inadequate in older adults. Isodecyl galactosides (ID-Gal) inhibits bacterial co-aggregation and could promote the maintenance and improvement of oral hygiene. In this study, the efficacy of ID-Gal-containing foam dentifrice in oral hygiene among older adults was evaluated.

Methods: Fifty-six subjects aged 65 years or older visited Tokushima University Hospital and were randomly assigned to interventions using ID-Gal-containing foam dentifrice applied to the dorsum of the tongue, or to controls using their usual dentifrice. Microbiological and clinical oral health parameters were evaluated before, and at 1 and 2 months after the intervention.

Results: The intervention group showed significant decreases in black pigment-producing bacteria on the dorsum of the tongue, Fusobacterium, and total bacterial counts on the mucosa below the denture base after 1 month. Additionally, the intervention group showed significant decrease in the Winkle Tongue Coating Index (WTCI) after 2 months.

Conclusion: ID-Gal-containing foam dentifrice decreased the number of bacteria by suppressing plaque formation and contributed to a reduction in the number of bacteria on the tongue and the WTCI. Collectively, these results suggest that ID-Gal-containing foam dentifrice is effective in maintaining and improving oral hygiene.

This study was conducted to clarify the usefulness of a newly developed occlusal force device. An arbitrary load was applied to the device 100 times, and the measured values were recorded. The loading and measured values were extremely close, and the error rate was fairly small. There was a close relationship between the occlusal force measured with a device based on the dental prescale and that measured using the new device. These results suggest that the newly developed device can measure and evaluate occlusal force with a degree of accuracy equivalent to the dental prescale.

Purpose: To compare the clinical success of different forms of vital pulp therapy using various pulp-capping materials.

Methods: Two independent researchers selected relevant articles from databases, extracted data, evaluated bias risk, and performed meta-analysis. Among 337 studies retrieved, 21 with a total of 1,816 participants and 1,948 treated permanent teeth were eligible and selected for 17 types of comparison. Meta-analysis was conducted for only six of these 17 comparisons.

Results: Among the six comparisons, the success of direct pulp capping with mineral trioxide aggregate (MTA) was significantly higher than that using calcium hydroxide (relative risk = 1.21, 95% confidence interval = 1.02-1.42, P = 0.03). There was no significant difference in the success of direct pulp capping between mineral trioxide aggregate and biodentine, nor between partial pulpotomy and full pulpotomy for either type of pulp capping material.

Conclusion: The use of MTA for direct pulp capping appears to yield significantly better clinical success than the use of calcium hydroxide.