European Oral Research最新文献

Purpose: To comparatively assess the color stability of indirect composite block, nanohybrid, and microhybrid resin composites after immersion in red wine and repolishing.

Materials and methods: Specimens (2x7x12 mm) were prepared using an indirect composite block (Cerasmart), a nanohybrid (Ceram X), and a microhybrid (Charisma Smart) resin composite. The specimens' color was recorded based on the CIE L*a*b* system in a spectrophotometer (Spectroshade). After recording the initial color, the specimens were immersed in red wine for 3 hours per day for 15 days. The color measurement was done again. The specimens were repolished with a multistep polishing system (SuperSnap). The color was measured for the third time. The color change values (ΔE) were calculated with the L*, a*, and b* coordinates obtained at baseline, after the immersion procedure, and after repolishing. Statistical analyses were performed with one-way ANOVA, Tukey's post hoc, and paired t-tests (p=0.05).

Results: The composite block presented the lowest ΔE value (p <0.05). No statistically significant difference was found between the ΔE values of the nanohybrid and microhybrid resin composites. The repolishing promoted a decrease in the color change of all three materials (p<0.05). The ΔE value of the composite block was clinically acceptable after repolishing.

Conclusion: The composite block showed higher color stability. The staining resistance of the nanohybrid and microhybrid resin composites was not different. The repolishing decreased the discoloration of all three materials.

Purpose: Dental students are particularly prone to be affected by the global emergency of Coronavirus-19 (Covid-19) pandemic. The aim of this study was to evaluate the professional motivations and perceptions of senior dental students during the distance education period due to pandemic.

Materials and methods: The data was collected via an online questionnaire, including questions related to students' professional motivation and perceptions, and views about preventive dentistry. For identifying the distress levels, Turkish version of Depression Anxiety Stress Scale (DASS)-21 was used. Descriptive statistics and marginal homogeneity test were used for statistical analysis.

Results: A total of 114 (83 female, 31 male) students, with the mean age of 23.7±1.03 participated the study. Statistically significant changes were observed on the students' career plans (p<0.001); fear about getting and transmitting infectious diseases (p<0.001); and satisfaction about their profession (p<0.001) during the Covid-19 pandemic. Motivation loss was determined on the participants.

Conclusion: There is an urgent need for revision on dental education in order to ensure the students be competent to provide oral health service that can meet the latest needs and achieve professional self-confidence without deterioration on their professional motivation and perceptions. Crisis-oriented psychological support programs should be provided for students. Some improvements should be structured in terms of preventive dentistry issues, both for dental education and dental health service aspects.

Purpose: The aim of this retrospective research is to compare frontal sinus dimensions in skeletal Class I, skeletal Class II, and skeletal Class III individuals and to evaluate the relationship of these dimensions with anterior skull base length and some cephalometric values.

Materials and methods: In this research, we used lateral cephalometric radiographs of 60 people aged 17 to 25. In individuals with skeletal Class I malocclusion, skeletal Class II malocclusion due to mandibular insufficiency, and skeletal Class III malocclusion due to mandibular excess, measurements of frontal sinus length and height as well as S-N, Co-A and Co- Gn lengths, ANB0, FMA0, SN-GoGn0 angles values were performed. The length between the highest point and the lowest point of the frontal sinus was calculated as the height of the frontal sinus, and the length between the most anterior and the most posterior points of the frontal sinus was calculated as the length of the frontal sinus.

Results: The frontal sinus length and height were found to be higher in skeletal Class III individuals than in skeletal Class I and skeletal Class II individuals, however, there was no significant difference between skeletal Class I and Class II individuals.

Conclusion: The increase in frontal sinus height and length correlated positively with the decrease in the ANB angle and the increase in the SN and Co-Gn lengths. The dimensions of the frontal sinus may be an indicator for the remaining mandibular growth potential.

Purpose: The objective of this experimental invitro study was to investigate the effects of resin infiltration (RI) on surface roughness, microhardness, color and surface characteristics of artificially demineralized root surfaces.

Materials and methods: Forty-two root specimens prepared from freshly extracted intact human upper incisors were subjected to surface roughness, microhardness, and color tests. Profilometer was used to measure surface roughness and Vicker's Hardness tester was used to measure the changes in microhardness. The color measurements were performed by a spectrophotometer using the CIELAB parameters. Following measurements, specimens were divided into 3 groups (n=14): G1: intact root surfaces, G2: demineralized root surfaces and G3: Resin infiltrated root surfaces (Icon, DMG) following demineralization. Surface roughness, microhardness and color measurements were repeated in G2 and G3 after demineralization and RI. One specimen from each group was examined by SEM. Data were analyzed statistically (p<0.05).

Results: Application of RI to artificially demineralized root surfaces significantly decreased the surface roughness (p<0.001) and increased the microhardness (p=0.023). RI also affected the color of demineralized root surfaces. SEM examinations revealed that the porosities on demineralized root surfaces seemed to be sealed after RI.

Conclusion: RI affected the surface roughness, microhardness, color and surface appearance of artificially demineralized root surfaces.

Purpose: The aim of this study was to determine descriptive characteristics of dental students, to investigate their professional expectations, career decision criteria, and related factors; to examine how (if any) seniority in school affects these.

Subjects and methods: During the period of 2018-2019, all 1-5 grade students (n = 754) of Hacettepe University Dental School were invited to participate and those who accepted had filled under observation a standard questionnaire form of 35 questions (83.4%). In the analysis of the data, descriptive statistics, chi-square, Student's t-test and ANOVA and Odds ratio methods were used.

Results: In this cross-sectional study, 66% of the group were female, age range was 18-30 (mean±SD= 21.2 ± 1.7). The most common reasons for choosing dentistry were "financial benefits", "job security" and "professional status". "Undertake specialist training" (80.2%) was the most common short-term expectation after graduation; two most common long-term expectations were "having a private clinic" (57.9%) and "completing specialization training" (56.0%). The most important factors affecting the post-graduation working plans were work-life balance and economic stability.

Conclusion: It is recommended to provide adequate counseling and guidance to students about potential career paths to maximize a balanced and widely accessible oral health service delivery across the country with more motivated dentists. Qualitative research may improve our understanding of how dental education can be improved to fulfill students' expectations from school, and to motivate dental students towards general practitioning in the future.

Purpose: To compare skeletal and dentoalveolar measurements of subjects with unilateral impacted canine versus the non-impacted contralateral side using cone beam computed tomography (CBCT).

Materials and methods: 30 CBCTs with unilaterally impacted maxillary canines (Buccal=15, Palatal=15) were selected. Skeletal and dentoalveolar variables (alveolar ridge height of incisors, dentoalveolar height, angulations of incisors and canines, basal lateral width and premolar width) were compared between the impacted and the contralateral sides. Independent t-test was used to compare the variables.

Results: There was a significant difference in the mean basal lateral width between the impacted (28.25±1.83 mm) and non-impacted (31.64±2.18 mm) sides. Premolar width was significantly lower on the impacted side (p<0.05). The canines exhibited significantly greater angulations on the impacted side compared to the nonimpacted side. The basal lateral width was significantly higher in the buccal subgroup (29.03±1.65mm) compared to palatal (27.48±1.70mm) on the impacted side. The intra-operator reliability was found to be high (0.99%).

Conclusion: Significant differences were seen in canine angulation, premolar width and basal lateral width between impacted vs. non impacted sides. Basal lateral width was higher in buccal impacted cases compared to palatal.

Purpose: Polymethylmethacrylate denture bases are prone to fracture, so reinforcement of dentures with nanoparticles is required to overcome these challenges. This invitro study was done to assess the effect of reinforcement with nanoparticles of polyetheretherketone (PEEK), zirconium oxide (ZrO2) and its mixture on flexural strength of polymethylmeythacrylate resin.

Materials and methods: A total of 60 acrylic resin specimens measuring 65 mm × 10 mm × 2.5 mm were fabricated. The specimens were divided in to fifteen specimens in each group [control group (C), 3wt% PEEK group (P), 3wt% zirconia group (Z), and hybrid reinforcement of 1.5wt% PEEK and 1.5wt% ZrO2 group (P-Z)]. The flexural strength of the specimens was evaluated using a three-point bending test on a universal testing machine. The statistical analysis was done using one-way analysis of variance (ANOVA), and the intergroup comparison was done using Tukey's post hoc analysis.

Results: The mean flexural strength was maximum in group P-Z (98.73MPa) followed by group P (86.22 MPa) and group Z (84.48 MPa). The mean flexural strength was least in the control group (74.86MPa). One-way ANOVA revealed a highly significant (P<0.01) difference among the groups. Pairwise comparison among groups showed a significant difference (P<0.05) among all the groups except in between groups P and Z where no significant difference was found (P=0.406).

Conclusion: Hybrid reinforced PEEK and zirconia could be used as an effective reinforcement material for denture base resin. The hybrid PEEK and zirconia reinforced resin can be an alternative treatment option in patients with heavy occlusal forces and for patients who have previous experience of multiple denture fractures.

Purpose: The aim of this study was to compare the effects of two different mandibular advancement methods on skeletal, dentoalveolar, and soft tissue structures through cephalometric measurements.

Materials and methods: The aim of this study was to compare the effects of two different mandibular advancement methods on skeletal, dentoalveolar, and soft tissue structures through cephalometric measurements.

Results: The mandibular base was observed to move forward significantly in both groups (p<0.05). However, the forward movement of the mandibular base was greater in the TB group than in the EA group (p<0.05). There was no difference in lower incisor protrusion between the two treatment methods. The EA device was found to cause a significant increase in vertical direction parameters (p<0.05).

Conclusion: Both methods resulted in Class II malocclusion correction as well as an acceptable occlusion plus profile. The effects of EA were primarily dentoalveolar. In patients with high aesthetic expectations, EA could be an alternative for TB.

Purpose: The movement of chewing affects the growth and development of the stomatognathic system. Tooth decay, which is known to have effects on chewing, can affect the jaw bone due to its indirect effect on the mechanical forces transmitted to the jaw bone. This study aimed to evaluate the relationship between dental caries and jawbone trabeculation during the growth and development processes in children using fractal dimension (FD) analysis.

Materials and methods: A total of 120 patients were divided into three groups. The groups were determined as follows: group 1: 40 patients without deep dentin caries/apical rarefying osteitis, group 2: 40 patients with deep dentin caries/apical rarefying osteitis on the right or left sides, and group 3: 40 patients with deep dentin caries/apical rarefying osteitis on both the right and left side. Digital panoramic images of the selected patients were evaluated using FD analysis.

Results: There was no statistically significant difference in the FD analysis among the groups. Age and sex factors were not found statistically significant in the in-group evaluation (p>0.05). In group 3, FD values of the right condyle (r= -0.42, p<0.05), right ramus (r= -0.37, p<0.05) and left ramus (r= -0.45, p<0.05) were negatively correlated with age.

Conclusion: There is no relationship between tooth decay and trabeculation of the jawbone in children aged 8-13 years.

Purpose: This study aimed to investigate the effect of five porcelain repair systems on shear bond strength in composite and zirconia infrastructures and to identify the bond failure mode after thermocycling.

Materials and methods: Disk-shaped zirconia samples (n=50) were divided into five groups (n=10) according to repairing system type. Each repair system was applied to the zirconium samples and a hybrid composite was used for repairing. Shear bond testing of all groups was carried out using a universal testing machine after thermocycling.

Results: Repair systems demonstrated no significant difference in repairing zirconia except Single Bond. Single Bond was the weakest in repairing the infrastructures. The highest and lowest mean bond strength values for the zirconia groups were 18,91 MPa and 3,63 MPa, respectively.

Conclusion: The three repair systems, Ivoclar, Clearfil, and Bisco, were more effective than the Single Bond and Ultradent repair systems in repairing zirconia, and their bond failure modes were both mixed and adhesive.