European Oral Research最新文献

Purpose: This study was to compare and evaluate the effect of home bleaching on the microhardness and flexural strength of microhybrid and nanohybrid composite resins.

Materials and methods: The study samples were prepared using a custom-made silicon rubber mold. For microhardness evaluation, 40 disc-shaped specimens (4mm*2mm) were prepared and divided into 4 groups: GROUP A (n=10): microhybrid (GC Solaire X, GC Corporation) control group, GROUP B (n=10) nanohybrid (Tetric N Ceram, Ivoclar Vivadent) control group, GROUP C (n=10): microhybrid bleaching group, GROUP D (n=10) nanohybrid bleaching group. For flexural strength evaluation, 40 bar shaped specimens (25mm*2mm*2mm) were prepared. They were divided into 4 groups, GROUP 1 (n=10): microhybrid control group, GROUP 2 (n=10) nanohybrid control group, GROUP 3 (n=10): microhybrid bleaching group, GROUP 4(n=10) nanohybrid bleaching group. All the control groups were placed in artificial saliva and bleaching groups were exposed to home bleaching agent for 14 days according to manufacturer's instructions. The microhardness and flexural strength were evaluated for the respective specimens after 14 days and the data were statistically analyzed.

Results: Home bleaching regimen decreased microhardness of both microhybrid and nanohybrid composites whereas there was no significant effect on the flexural strength. Nanohybrid composites showed greater microhardness values before and after bleaching.

Conclusion: Bleaching agents, irrespective of their concentration can decrease the microhardness of the composite resin samples, which raises a concern about replacement of these restorations due to the effects on physical and mechanical properties.

Purpose: The aim of this study was to assess the impact of exposure parameters and image formats on fractal dimension (FD) values in periapical, panoramic, and CBCT images.

Materials and methods: Seven dry male mandibles were selected, and a Gutta-Percha was used to identify identical regions of interest. A periapical radiograph was taken with 60 kVp/7 mA and exported in DICOM, JPEG, TIFF, and PNG formats. Nine periapical radiographs (60, 65, 70 kVp; 4, 5, 6 mA) were taken from seven dry human mandibles. Additionally, 12 panoramic radiographs (60, 70, 81, 90 kVp; 5, 8, 13 mA) and 10 CBCT images (with different scanning options and FOVs) were taken from each mandible. FDs were measured from a standard area.

Results: The intra-class correlation coefficient demonstrated a high degree of agreement between observers. No significant difference was found between TIFF and PNG formats (p > 0.05). The highest FD mean was found in TIFF format, while the lowest FD mean was found in JPEG format (p<0.001). There was no significant difference between kVp and mA settings in periapical images. In panoramic images, a significant difference was found at 90 kVp (p = 0.001) and 13 mA (p<0.001), with lower FD values observed at these settings. There was no significant difference between FOV and resolution in CBCT images (p > 0.05).

Conclusion: The format of the image can influence FD. For periapical and panoramic radiographs, kVp and mA settings do not have a significant impact on FD. However, fractal analysis may not be an ideal method for evaluating three-dimensional images, such as those obtained with CBCT.

Purpose: Tooth avulsion is a type of trauma that requires emergency intervention, and a significant number of patients apply to the emergency. The aim of this study is to evaluate the level of knowledge and the awareness about tooth avulsion among emergency medicine physicians throughout Turkiye.

Materials and methods: The study was conducted with 545 physicians, working in emergency departments. An online questionnaire about tooth avulsion was applied to the participants. The questionnaire consisted of 3-section which evaluated personal information, the level of knowledge of avulsion cases in primary and permanent dentition, and the level of training on this subject.

Results: Of the physicians, 61.3% had not previously received education on dentoalveolar traumas, 58.7% would replant an avulsed permanent tooth, 28.3% would prefer replantation to be performed "immediately", and 28% would prefer milk as the ideal storage medium. The mean±SD and median(min-max) values of the correct answer scores on a scale of 0 to 35 were 16.42±7.08 and 17(0-32), respectively. 45.6% of the physicians' level of knowledge was below the median score.

Conclusion: The level of knowledge about tooth avulsion among Turkish emergency medicine physicians is not sufficient and there is a need to improve the knowledge level of physicians with comprehensive educational programs. This study indicates that the training of the physicians about the subject will reflect positively on the treatment of dental trauma patients.

Purpose: To evaluate color differences in repair of indirect ceramic and resin nanoceramic CAD/CAM blocks with two universal shade composites after different surface preparations.

Materials and methods: 120 samples were prepared from IPS Empress and GC Cerasmart270 CAD/ CAM blocks and thermocycled (5000 cycles, 5°C-55°C). Initial colors of sample surfaces were measured using a spectrophotometer. Rectangular prism-shaped cavities were prepared and repaired with Tokuyama Universal Bond/Omnichroma and G-Multiprimer/G-Premio/Essentia Universal following surface preparation with aluminum oxide, Cojet, and bioactive glass (Sylc). Repaired samples were thermocycled (5000 cycles) and color measurement was performed. Color coordinates L*a*b* were recorded, and color differences were calculated using the CIELab formula. Color differences between pre-and post-repair (ΔE1) and between post-repair and post-aging (ΔE2) were determined. Data were analyzed using Three-way ANOVA with a significance level set at p<0.05.

Results: ΔE1 values in all subgroups exceeded the threshold of 3.3. No significant difference was found between the surface preparation processes regarding ΔE1 values. There was no significant difference between the composites and bonding agents in ΔE1 values, except for Cerasmart/Sylc and Empress/Sylc groups. No statistically significant difference was detected in ΔE2 values between the surface preparation treatments in all groups. (p >0.05).

Conclusion: Color match of the universal shade composites, which are preferred to increase the esthetic satisfaction and to simplify repair procedures, were found above the acceptable threshold. Post-aging color stability of universal shade composites was below the acceptable threshold.

Purpose: Airway dimensions associated with the transversal and sagittal position of the maxilla are affected by orthodontic treatment. The objective of this study was to compare the effects of rapid maxillary expansion (RME) and RME followed by face mask (FM) therapies on the airway space and investigate whether application of the FM increases the short-term and long- term impact of RME on sagittal airway dimensions.

Materials and methods: A total of 26 patients were divided into two groups. Group I included 14 adolescents treated with RME (3 males, 11 females; mean age: 12.2 11 ± 2.1 years), and Group II included 12 adolescents treated with RME followed by FM therapy (7 males, 5 females; mean age: 11.6 ± 1.3 years). Sagittal and vertical skeletal measurements, as well as ten linear cross-sectional airway measurements, were calculated from pretreatment, posttreatment, and postretention cephalometric radiographs.

Results: RME followed by FM resulted in a significant increase in the SNA angle, ANB angle, and Wits parameter by the forward movement of the maxillary bone. A significant increase in the vertical dimensions was also observed. Regarding the airway measurements in both groups, significant oropharyngeal increases were revealed, and these were maintained in the follow-up period. However, there were no other significant differences in the short-term and long-term results obtained for Groups I and II.

Conclusion: The dimensions of the airway were significantly affected by both therapies. However, no additional effect of FM was observed.

Purpose: This study aims at determining the amount of mercury released over time from amalgam after treatment in healthy subjects and to examine the relation of mercury with serum MT-1 and SOD-1 levels.

Materials and methods: Amalgam filling was applied to the 15 subjects aged 19-22 years and blood samples were collected before treatment and 1 day, 7 days, 21 days and 35 days after treatment. Mercury analysis of serum samples was performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In addition, MT-1 and SOD-1 levels in serum samples were measured using commercial enzyme-linked immunosorbent assay (ELISA). Friedman test and Spearman's correlation analysis was performed to analyse the data. p value was interpreted in significance level of 0.05.

Results: As a result of the analysis for MT-1, it was found that the values decreased over time and this decrease was statistically significant after 21 days (p<0.05). In addition, it was found that SOD-1 decreased over time, but this decrease was not statistically significant . In terms of released mercury, there was no statistically significant difference among the values of mercury released over time . According to the results of correlation analysis, no statistically significant relationship was found among the variables.

Conclusion: The results of the present study indicated that the amount of mercury released from the tested amalgam were found to be tolerable and no significant relationship was found between MT-1 and SOD-1.

Purpose: The aims of our study were to determine the changes in the pharyngeal airway after treating patients with Class III malocclusion who received double jaw surgery, to determine the hard tissue and soft tissue parameters and the hyoid bone and tongue positions after surgery, to determine the changes to compare the pretreatment and post-treatment measurements of the patients in the double jaw group with the measurements of the control group patients, and to evaluate postoperative patient satisfaction.

Materials and methods: The study included thirty-two Class III adult patients that received double jaw surgery and twenty-five Class I patients. Cephalometric records were taken before treatment (T1) and after treatment (T2).

Results: After double jaw orthognathic surgery, there were statistically significant changes in all pharyngeal airway linear and areal parameters (p<0.001). There were significant superior and posterior movements of the tongue and hyoid bone post-surgery. The post-treatment analysis of the double jaw surgery group and control group were compared, with statistically significant differences in the mandibular dental parameters and pharyngeal airway measurements in patients in the double jaw surgery group.

Conclusion: Despite the narrowings detected, high satisfaction scores were observed in the patient satisfaction questionnaire and the patients did not experience respiratory problems.

Purpose: This study was conducted to investigate the fracture strength of reattached tooth fragments after different cavity disinfection protocols.

Materials and methods: Incisal edges of 144 bovine incisors were sectioned and then randomly divided into 4 different groups as follows: Group C: no disinfectant; Group NaOCl: 2.5% sodium hypochlorite solution; Group NaOCl+Asc: 2.5% sodium hypochlorite followed by 10% ascorbic acid solution; Group CHX: 2% chlorhexidine solution. Teeth were further divided into 3 subgroups according to universal adhesive (G-Premio Bond, Scotchbond Universal, Prime and Bond Universal). Fracture resistance was evaluated using a universal testing machine. Data was analyzed using 2-way ANOVA with Bonferroni tests.

Results: Cavity disinfectant had a statistically significant effect on bond strength (p<0.05), with the highest bond strength detected in the NaOCl+Asc Group (148.22 ± 51.64) and the lowest in the NaOCl Group (112.84 ± 43.12). Scotchbond Universal exhibited the highest bond strength values (163.59 ± 49.94); however, there were no significant differences between the other adhesive systems (p> 0.05).

Conclusion: Application of ascorbic acid following sodium hypochlorite treatment can improve dentin bond strength.

Purpose: Excessively produced heat could lead to clinical failure of osseointegration. This study was done to compare the heat generated during osteotomy with the conventional drill, trephine, and alveolar expander .

Materials and methods: This in vitro study was performed on ten bovine femoral bones. In each femoral bone, three osteotomy sites were prepared at a distance of 1.5cm using the conventional drill, trephine, and alveolar expander. During osteotomy, the site was irrigated with a copius amount of normal saline. Osteotomy sites of 3.6 mm in diameter and 11.5 mm in length were prepared using the conventional drill and bone trephines. The alveolar expander used for preparing the osteotomy site was 3.5mm, the nearest dimensions available. The temperature rise was measured using a thermocouple thermometer. Repeated measures ANOVA and Fisher's least significant difference pairwise comparison test was done for statistical analysis.

Results: Repeated measures ANOVA revealed a significant difference in the heat generation with the conventional drill, trephine, and alveolar expander (p<0.001). The mean heat generated was maximum with the trephine (28.26±0.246 0C) followed by the conventional drill (27.27±0.297 0C) and least with alveolar expander (25.64±0.142 0C). Pairwise comparison showed a significant difference in heat generated during osteotomy with conventional drill compared to trephine (P=0.023), conventional drill compared to alveolar expander (P=0.014), and trephine compared to alveolar expander (P<0.001).

Conclusion: The heat generated with trephine was maximum compared to the alveolar expander and conventional drills. If in case trephine is to be used, both internal and external irrigation must be used. Less heat generation during osteotomy by alveolar expander seems very promising and advantageous for better osseointegration.

Purpose: The aim of this study was to examine the flexural strength of acrylic resin base material incorporated with iron, copper, and titanium nanoparticles.

Materials and methods: Seventy bars of samples (65x10x2.5 mm3) were divided into seven groups. Acrylic samples were prepared according to the manufacturer's instructions. Fe2O3, CuO and TiO2 nanoparticles were manually added in a proportion of 1wt% and 3wt% to the heat-polymerized acrylic resin. The Universal Testing Machine was used for 3-point flexural test of 5 mm/min force. ANOVA and Weibull analyses were used for the statistical analyses.

Results: A statistical difference was found between the nanoparticle-added group and the control group. The highest mean value was observed for the 1wt% TiO2 added group, (84.99 MPa) and the lowest value was for the 3wt% CuO added group (71.32 MPa) (p<0,001). The 3wt% Fe2O3 and CuO added groups showed lower values than the control group.

Conclusion: The incorporation of TiO2 nanoparticles into acrylic resin in a proportion of 1wt% increased the flexural strength values of the resins. Within the limitations, the nanoparticle addition to acrylic resins could improve the mechanical properties; however, when the percentage of nanoparticle addition increases, the flexural strength values of the acrylic resins decrease.