Journal of oral science最新文献

Purpose: This study investigated the fluorescence intensity and color changes of tooth-colored dental materials under experimental conditions similar to those of charred bodies, from which dental evidence can be obtained.

Methods: Among 160 composite resin (CR) and glass ionomer cement samples, the fluorescence intensity was measured using a spectrofluorometer. CIELAB color space (L*a*b*), difference in lightness (ΔL*), and CIEDE2000 color difference (ΔE00) were calculated for all samples.

Results: The fluorescence intensity of CR was significantly higher in the flow type than in the paste type, and the A1 shade showed significantly higher intensity than the A3 before and after heating. The flow and paste type of the universal shade type CRs showed similar fluorescence to the A1 of conventional CRs before heating and tended to lose its fluorescence and transparency upon heating more easily than the conventional CRs. CR fluorescence intensity decreased significantly after 10 min of heating at 300°C, and many samples lost their fluorescence after 30 min. In contrast, glass ionomer cement fluorescence intensity increased with heating. ΔL* and ΔE00 were consistent with the macroscopic findings.

Conclusion: The findings of this study provide updated information on tooth-colored dental materials and help us understand the circumstances in charred cases.

Purpose: As the anatomy of proximal contact areas affects the risk of dental caries in primary molars, this study aimed to assess the impact of different resin and matrix systems on the geometry of reproduced proximal surfaces in primary molars.

Methods: Sixty mandibular primary first molar typodont teeth were prepared with standardized disto-occlusal cavities. Two experimental groups were created: Group I utilized GC UniFil Flow and Filtek Z250 XT; Group II utilized SDR Plus Bulk Fill Flowable Composite and Ceram.x Spectra ST. Each group was further subdivided into the Palodent V3 sectional matrix system (P) and the Tofflemire matrix system (T). Digital evaluations were then performed to calculate discrepancies.

Results: Significant discrepancies were found only between Group IT and Group IIP in the middle third (P < 0.05). Average root mean square values at proximal contact surfaces did not differ significantly among the groups. The proximal surface shape was also not significantly different.

Conclusion: Within the limits of this study, the reproduced proximal surface geometry was not significantly affected by the type of resin and matrix system.

Purpose: This study investigated effectiveness of a silicone mask fitter for reduction of composite particle leakage during removal of bonded attachments for clear aligners compared with a surgical mask and an N95 respirator.

Methods: Composite particles passing through masks were measured using a particle counter machine during removal of attachments bonded on a dentoform using a slow-speed handpiece. The samples were: Group 1: a surgical mask; Group 2: a surgical mask with a silicone mask fitter; and Group 3: an N95 respirator. The experiments were repeated six times per group. Differences among the groups were assessed using one-way analysis of variance and post hoc tests.

Results: The mean concentration of total composite particles behind the surgical mask with the silicone mask fitter was significantly lower than that behind a surgical mask alone (61.01 ± 13, 209.69 ± 66 particles/cubic foot (ft³)/min × 10³, respectively, P < 0.001), while there was not significantly different from the N95 respirator (12 ± 3 particles/ft³/min × 10³).

Conclusion: Use of a surgical mask alone was associated with significant leakage of composite dust. The effectiveness of the silicone mask fitter for preventing the entry of diffuse particles was comparable to that of the N95 respirator.

Purpose: The purpose of this study was to analyze the association between the number of medications and oral functions.

Methods: The study participants were selected from individuals who were attending regular follow-up as hospital outpatients. Patient profiles, the number of medications used, and measured values of oral function were extracted. These data were analyzed statistically for sex, age, and grouping according to the number of medications taken (no medication, G1; 1-4 medications, G2; ≥5 medications, G3). Conditional logistic regression analysis was performed to evaluate the effects of medications on oral function.

Results: A total of 172 patients (66 males and 106 females) were registered; 50 participants belonged to G1, 68 to G2, and 54 to G3. Significant inter-group differences were identified for tongue-lip motor function (oral diadochokinesis: ODK) and maximum tongue pressure in terms of age, but not in terms of sex. G3 showed significantly lower ODK than G1, and logistic regression analysis revealed that the number of medications was significantly associated with ODK/pa/. Age and MTP also significantly affected ODK/ta/ and /ka/.

Conclusion: Within the limitations of this study, the present findings suggest that the number of medications taken has an impact on tongue-lip motor function.

Purpose: This study aimed to investigate the minimum inhibitory concentration (MIC) and biological properties of modified glass-ionomer cement (BIO-GIC) supplemented with chlorhexidine diacetate (CHX).

Methods: The BIO-GIC was originally a combining formulation of conventional glass-ionomer cement, chitosan, albumin and tricalcium phosphate. CHX was incorporated at various concentrations of 1.25%, 2%, 2.5%, 5%, 7.5% and 10%. Antimicrobial activity against certain microorganisms related to cariogenesis Streptococcus mutans (S. mutans), Streptococcus sanguinis (S. sanguinis), and Enterococcus faecalis (E. faecalis), was evaluated by microdilution test. One effective concentration of CHX was mixed with Penaeus merguiensis-Translationally Controlled Tumor Protein (Pmer-TCTP) and further conducted by biological tests including cell viability and mineralization in dental pulp.

Results: S. mutans were inhibited at 7.5% CHX-modified BIO-GIC, while S. sanguinis and E. faecalis showed no inhibition at any concentration. Cell viability significantly decreased with 7.5% CHX-modified BIO-GIC after 72 h. Dental pulp exposed to this group formed smaller and fewer calcium nodules but adding Pmer-TCTP reduced cell death and slightly enhanced mineralization.

Conclusion: 7.5% CHX-modified BIO-GIC shows potential for inhibiting S. mutans and having potential cell viability and mineralization in dental pulp cells.

Purpose: To investigate the mineral density of artificial root caries lesions formed under varying concentrations of calcium phosphate, with or without the presence of fluoride.

Methods: Sixty-four human tooth root blocks were exposed to various lactic acid solutions for 96 h. These included a low concentration (0.16 mM) of calcium chloride and potassium dihydrogen phosphate (Group L), a low concentration (0.16 mM) of calcium chloride and potassium dihydrogen phosphate with 0.5 ppm fluoride (with sodium fluoride) (Group LF), a high concentration (2.2 mM) of calcium chloride and potassium dihydrogen phosphate (Group H), and a high concentration (2.2 mM) of calcium chloride and potassium dihydrogen phosphate with 0.5 ppm fluoride (Group HF). The mineral loss in the artificial lesions formed was measured using micro-computed tomography.

Results: The mineral loss in groups L, LF, H and HF was 35.38 ± 2.15%, 31.96 ± 2.1%, 32.58 ± 1.15%, and 27.78 ± 2.3%, respectively. A significant difference (P < 0.001) was observed between groups L and LF, groups LF and HF, groups H and HF, and groups L and HF. Calcium phosphate and fluoride exposure both had significant effects (P < 0.001) on mineral loss.

Conclusion: Artificial root caries lesions were associated with decreased mineral loss in solutions containing higher concentrations of calcium phosphate or in the presence of fluoride, compared with those formed in solutions with lower calcium phosphate concentrations or without fluoride.

This clinical report summarizes a workflow that introduces two approaches for fabricating a metal framework removable partial denture for a marginal mandibulectomy patient. First, the pre-existing denture was adjusted according to the piezographic technique to determine the optimal configuration for adhering to the available denture space. Second, computer-aided design-computer-aided manufacturing (CAD-CAM) technology was used to fabricate a new removable partial denture by digitally scanning the oral condition and the well-adjusted denture and then using the obtained data to design and fabricate the new denture. These two approaches can help to reduce chair time not only for maxillofacial prosthetic treatment but also for other denture cases.

Purpose: To determine and compare the cytotoxicity, odontoblast-like differentiation, shear bond strength (SBS) and Vickers microhardness of four commercial light-cured orthodontic adhesives.

Methods: The orthodontic resins selected were Transbond XT - GI, Transbond Plus Color Change - GII (both from 3M Unitek), Enlight - GIII and Blugloo - GIV (both from Ormco). Samples were prepared, and leached monomers were obtained. Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and deposited calcium was analyzed using Alizarin red staining (ARS). SBS and the adhesive remnant index (ARI) were determined using 120 human premolars. The Vickers microhardness test was performed on the resin discs.

Results: All adhesives showed moderate to severe cytotoxicity (21-37%) and promoted similar formation of calcium deposits. A SBS of 6-8 MPa was achieved only by Blugloo (7.1 ± 2.4 MPa), and Enlight showed the lowest Vickers hardness score (40 ± 2.5 HV). Transbond Plus Color Change (score 0 = 42.9%) and Blugloo (score 0 = 46.4%) showed better ARI scores than Transbond XT (score 0 = 7.1%) and Enlight (score 0 = 3.6%).

Conclusion: On the basis of the properties evaluated, Blugloo seems to be the best option.

Purpose: Non-vital teeth usually exhibit substantial loss of coronal and radicular tooth structure, and use of posts after root canal treatment is controversial. This review examined whether placement of posts influences clinical behavior and survival probability of endodontically treated teeth (ETT).

Methods: An electronic search, without time restrictions, for publications written in English was undertaken in PubMed, Scopus, and Web of Science. Terms related to four main components (endodontically treated teeth, fixed prosthesis, post restoration, and survival rate) were used for the database search strategies.

Results: 57 studies met the inclusion criteria and were included in the qualitative analysis. Of the publications chosen for qualitative analysis, 17 clinical studies (11 prospective and 6 retrospective studies) were found to be suitable for quantitative analysis. These studies included 7,278 patients (7,330 ETT), with a mean age ± standard deviation (SD) of 45.46 ± 12.1 years. There was a statistically significant difference in survival rate between ETT with or without posts (P < 0.001).

Conclusion: As compared with teeth with no posts, post placement on ETT may improve clinical performance and survival probability of endodontically treated teeth.

Purpose: This study evaluated transportation and extruded debris during preparation using different instruments.

Methods: Sixty resin blocks with S-shaped canals and 60 extracted teeth were separated into four groups (n = 15), which were instrumented with Reciproc Blue, XP-endo Shaper, WaveOne Gold, and Twisted File Adaptive. For evaluating transportation, pre- and post-preparation images were obtained under a stereomicroscope and superimposed with digital software. The distance between the inner and outer canal walls was measured. For the evaluation of debris extrusion, the samples were placed in Eppendorf tubes and instrumented using one of the four rotary files. The initial weight was subtracted from the post-instrumentation weight to determine the amount of extruded debris. The Kruskal-Wallis and Dunn multiple tests were performed.

Results: For transportation, no significant difference was found between the XP-endo Shaper-Twisted File Adaptive systems and between Reciproc Blue-WaveOne Gold groups (P > 0.05). The XP-endo Shaper and Twisted File Adaptive techniques led to significantly less transportation compared to the other systems (P < 0.05). Regarding debris extrusion, the XP-endo Shaper system extruded significantly less debris than the other groups (P < 0.05).

Conclusion: XP-endo Shaper extruded less debris compared to other groups, while XP-endo Shaper and Twisted File Adaptive caused less transportation than other files.