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Objectives: The aim of this study is to evaluate the effect of different surface treatments on the shear bond strength (SBS) of clear aligner attachments bonded to Bis-acryl provisional crowns. Methods: 120 cylindrical bisacrylic composite material (ProTemp type) specimens were prepared and divided into six groups (n = 20) based on surface treatment, control: (no treatment); super coarse grit diamond bur, carbide bur, alumina-blasting, non-thermal plasma treatment, and Er:YAG laser treatment. The features of treated surfaces were examined using scanning electron microscopy (SEM). A flowable composite resin (Transbond XT; 3M Unitek) was bonded to the specimens forming the attachment. Half of specimens were subjected to thermal cycling (5,000 cycles). SBS was measured before and after thermal cycling. Each specimen was loaded at the attachment/resin interface at a speed of 0.5â mm/min until failure. The nature of the failure was analyzed using the composite remnants index (CRI). Two-way ANOVA and Tukey HSD were used for data analysis α = 0.5. For CRI scores analysis, Kruskal-Wallis test and Dunn's multiple comparison were used as post-hoc test. Results: SEM analysis showed that all surface treatments altered surface properties and increase surface bonding area. The specimens treated with plasma, Er:YAG laser, and alumina-blasting had higher SBS values before and after thermal cycling. In comparison to control plasma, Er:YAG laser, and alumina-blasting showed a significant increase in SBS (P < 0.001) while carbide and diamond bur groups showed no significant differences (P > 0.05). Thermal cycling significantly decreased the SBS of control, carbide bur, diamond bur, and Er:YAG laser while no significant effect of alumina-blasting and plasma group. Er:YAG laser and plasma groups significantly exhibited more dominance for scores 2 and score 3 and the absence of score 0. Conclusion: Alumina-blasting, Er:YAG laser, or non-thermal plasma surface treatments increased the shear bond strength between clear aligner attachments and resin-based restorations.
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PURPOSE: To evaluate the effect of different printing orientations and post-polymerization time with thermal cycling on the translucency of 3D-printed denture base resins. METHODS: Heat-polymerized (HP) acrylic resin specimens were fabricated and 3D-printed denture base materials (NextDent, ASIGA, FormLabs) were printed with different printing orientations (0, 45, 90 degrees) and subjected to different post-polymerization times (15-, 30-, 60-, and 90-min). All specimens were polished and immersed in distilled water for 1 day at 37°C. CIEDE2000 was used to measure the translucency parameters (TP00) before and after thermal cycling (5000 cycles) recording the color parameters (L*, a*, b*) against a black and white background using a spectrophotometer. k-factors ANOVA followed by post hoc Tukey's test (α = .05) was performed for statistical analysis. RESULTS: The k-factors ANOVA test showed a significant effect of resin material, post-polymerization time, and printing orientation on translucency (p < 0.001). In comparison to HP, all 3D-printed resins showed lower translucency with all post-polymerization times and printing orientation (p < 0.001) except FormLabs resin (p > 0.05). For all 3D-printed resins, the translucency increased, with increasing the post-polymerization time (p < 0.001) and 60- and 90-min showed the highest translucency. For printing orientation, 90 and 45 degrees significantly showed high translucency in comparison to 0 degrees (p < 0.001). FormLabs showed significantly higher translucency when compared with NextDent and ASIGA per respective printing orientation and post-polymerization time. The translucency significantly decreased after thermal cycling for all tested resins (p < 0.001). CONCLUSION: The findings of this study demonstrated that the translucency of 3D-printed resins is influenced by the printing orientation, post-polymerization time, and resin type. As a result, choosing a resin type, and printing orientation, with a longer post-polymerization time should be considered since it may improve the esthetic appearance of the 3D-printed resins.
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Background/Purpose: Whether YouTube videos contain precise and adequate information on certain orthodontic procedures remains unclear. This study aimed to investigate the content and quality of YouTube videos on orthodontic elastics and identify the predictors of high-level content YouTube videos. Materials and Methods: Two hundred YouTube videos were screened for eligibility, and after applying the inclusion criteria, 133 videos were excluded. Student's t-test was used to compare the characteristics, quality parameters, and total content of the low-level and high-level content videos. Chi-square or Fisher's exact tests were implemented to identify the source and content element differences across low-level and high-level content videos. Pearson's correlation coefficients were used to determine the relationship between the total content score, video information and quality index (VIQI), and YouTube characteristics. Stepwise linear multiple regressions with forward selection were used to test the association of the YouTube characteristics and VIQI with the total content score. Results: Among 67 included videos, only 19.4% of videos were classified as high-level content videos. High-level content videos had significantly higher mean number of likes (MD = 4041.7; SD = 4680.7; P-value=0.0068), VIQI score (MD = 4.17; SD = 4.87; P-value=0.0073), and total content score (MD = 4.04; SD = 1.23; P-value=<0.0001). The adjusted linear regression model demonstrated a significant association between the total content score and VIQI, where 1 unit increase in the VIQI was significantly associated with a 0.16 increase in the total content score (B = 0.16; standard error [SE]=0.04; P = 0.0003). Further, a significant association was observed between the total content score and video duration, where 1 minute increase in the video duration was significantly associated with a 0.15 increase in the total content score (B = 0.15; SE = 0.05; P = 0.008). Conclusion: This study demonstrated that YouTube content quality concerning orthodontic elastics is poor. Thus, future implementation of online visual content provided by certified orthodontists will ensure accurate and thorough information delivery.
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Three-dimensionally (3D)-printed fabricated denture bases have shown inferior strength to conventional and subtractively fabricated ones. Several factors could significantly improve the strength of 3D-printed denture base resin, including the addition of nanoparticles and post-curing factors. This study evaluated the effect of TiO2 nanoparticle (TNP) addition and the post-curing time (PCT) on the flexural properties and hardness of three-dimensionally (3D)-printed denture base resins. A total of 360 specimens were fabricated, with 180 specimens from each type of resin. For evaluating the flexural properties, bar-shaped specimens measuring 64 × 10 × 3.3 mm were used, while, for the hardness testing, disc-shaped specimens measuring 15 × 2 mm were employed. The two 3D-printed resins utilized in this study were Asiga (DentaBASE) and NextDent (Vertex Dental B.V). Each resin was modified by adding TNPs at 1% and 2% concentrations, forming two groups and an additional unmodified group. Each group was divided into three subgroups according to the PCT (15, 60, and 90 min). All the specimens were subjected to artificial aging (5000 cycles), followed by testing of the flexural strength and elastic modulus using a universal testing machine, and the hardness using the Vickers hardness test. A three-way ANOVA was used for the data analysis, and a post hoc Tukey's test was used for the pairwise comparisons (α = 0.05). Scanning electron microscopy (SEM) was used for the fracture surface analysis. The addition of the TNPs increased the flexural strength in comparison to the unmodified groups (p < 0.001), while there was no significant difference in the elastic modulus and hardness with the 1% TNP concentration. Among the TNP groups, the 2% TNP concentration significantly decreased the elastic modulus and hardness (p < 0.001). The SEM showed a homogenous distribution of the TNPs, and the more irregular fracture surface displayed ductile fractures. The PCT significantly increased the flexural strength, elastic modulus, and hardness (p < 0.001), and this increase was time-dependent. The three-way ANOVA results revealed a significant difference between the material types, TNP concentrations, and PCT interactions (p < 0.001). Both concentrations of the TNPs increased the flexural strength, while the 2% TNP concentration decreased the elastic modulus and hardness of the 3D-printed nanocomposites. The flexural strength and hardness increased as the PCT increased. The material type, TNP concentration, and PCT are important factors that affect the strength of 3D-printed nanocomposites and could improve their mechanical performance.
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BACKGROUND: Body dysmorphic disorder (BDD) is a common disorder that consists of a distressing or impairing preoccupation with imagined or slight defects in appearance. In dentistry, those patients will have unrealistic expectations and usually will be unsatisfied with the outcomes of dental treatment. This study investigated the prevalence of BDD and its associated factors among dental patients. MATERIAL AND METHODS: In this cross-sectional survey-based study, a purposive sample was used to recruit adult patients seeking dental treatment in private and public facilities. Data was collected using the validated Arabic version of the Cosmetic Procedure Screening Questionnaire (COPS) for Body Dysmorphic Disorder, a validated nine-item self-administrated instrument that is scored from zero (least impaired) to five (most impaired). Chi-Square, Mann-Whitney U, and Fisher's Exact tests were used to compare the associations between the study variables and BDD. RESULTS: A total of 507 patients responded to the questionnaire. The prevalence of BDD was 34.1%. The average age of the participants was 35.2 years; the majority were males 290 (57%) and Saudis 436 (86%) with a college education 304 (60%). None of the demographics was associated with BDD but the type of treatment was significantly associated with BDD with teeth crowning and restorations. CONCLUSION: This study provides insights into the prevalence of BDD and its associated factors among dental patients in Eastern Saudi Arabia. The findings highlight the need for further research to better understand the factors contributing to the development of BDD and to guide prevention and intervention strategies in dental settings.
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PURPOSE: To compare the microbial flora, alkaline phosphatase (ALP) and interleukin-8 (IL-8) levels during orthodontic treatment with self-ligating brackets versus conventional brackets. PATIENTS AND METHODS: Forty patients were included in this study and distributed equally between two groups. One group received conventional edgewise brackets while the other group received DAMON self-ligating brackets. Periodontal parameters were recorded and biochemical and microbial analyses were conducted before bonding (baseline), and 14, 30, and 45 days after bonding. Paired t-test was performed to estimate the intergroup differences from the baseline at the various time points; unpaired t-test was used for intragroup comparisons. RESULTS: A significantly higher prevalence of gram-negative as well as gram-positive microorganisms was found in the group with conventional brackets than that with self-ligating brackets. Alkaline phosphatase (ALP) activity and interleukin-8 (IL-8) levels were significantly higher in the gingival crevicular fluid of the group with conventional brackets than that with self-ligating brackets. CONCLUSION: The conventional bracket-ligature technique exhibited an increase in IL-8 levels, ALP activity, and microbial colonization compared with that of the self-ligature technique. Accordingly, self-ligating brackets are recommended in orthodontic patients to improve periodontal health and minimize damage outcomes of periodontal tissue interventions.
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AIM: To evaluate the effects of LLL on IL-6 levels in the GCF and the Probing Pocket Depth measurements (PPD) during orthodontic tooth movement in periodontally affected rabbits. METHODS: Twenty-four rabbits were divided into 3 groups: Group 1(G1), healthy rabbits with orthodontic movement, Group 2(G2) periodontally affected rabbits and orthodontic movement, Group 3(G3) periodontally affected rabbits with orthodontic movement and LLL therapy. A 0.014 stainless steel spring was inserted in the upper central incisors to produce 60gm force. Laser CAT 500 was applied for 3min/day for 2 weeks. PPD measurements were obtained at base line and after 14 days with electronic periodontal probe. RESULTS: IL-6 levels increased gradually after application of orthodontic force, afterwards the 8th day, a significant difference in the Il-6 levels between G1 vs. G2 and G2 vs. G3 was observed. PPD measurements showed significant difference between the three groups at base line and after 14 days. CLINICAL SIGNIFICANCE: LLL application can enhance periodontal ligament regeneration and decrease the periodontal tissue destruction through suppression of IL-6 levels.
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Líquido del Surco Gingival/metabolismo , Interleucina-6/análisis , Rayos Láser , Técnicas de Movimiento Dental , Animales , Citocinas/análisis , Incisivo , Masculino , Modelos Animales , Ligamento Periodontal , Bolsa Periodontal , ConejosRESUMEN
OBJECTIVES: To evaluate the dental and skeletal effects of chin cup using two different force magnitudes in the management of Class III malocclusion cases. MATERIALS AND METHODS: Fifty growing patients (26 males and 24 females) with skeletal Class III and mandibular prognathism were selected. The patients were divided into three groups. Patients in group 1 (n = 20) were treated with a chin cup and occlusal bite plane using 600 g of force per side. Patients in group 2 (n = 20) were subjected to the same treatment as in group 1 but using 300 g of force per side. In group 3 (n = 10) no treatment was performed. For all patients, lateral cephalograms were taken before treatment and after 1 year. Cephalograms were traced and analyzed. The collected data were analyzed statistically using one-way analysis of variance and the Tukey test. RESULTS: In the treatment groups, the SNB angle and ramus height decreased significantly. The ANB angle, Wits appraisal, anterior facial height, mandibular plane angle, and retroclination of the mandibular incisors were significantly increased in comparison to the control group. Utilization of either force showed no significant differences, except that the reduction in the ramus height was significantly greater with the use of higher force. CONCLUSIONS: The use of a chin cup improved the maxillomandibular base relationship in growing patients with Class III malocclusion but with little skeletal effect. The utilization of either force had the same effects, except that the higher force had a more pronounced effect in reduction of ramus height.