Significant Differences In Strength Research Articles

Pengaruh Sudut Part Build Orientation Z-Direction Terhadap Kuat Tarik Spesimen Uji Standar Astm D638 Type IV Menggunakan Filamen Pla+

This study will try to investigate variations in the angle of the Z-direction build part by using a 3D Printer with Fused Deposition Modeling (FDM) technology made from PLA + Sugoi. This study uses a 0.4mm nozzle with a Bowden type extruder. This study uses a PLA+ filament from the Sugoi brand with a nozzle of 0.4 mm, diameter filament 1,75 mm, 3D Printer with Fused Deposition Modeling (FDM) technology used is Creality Ender 3 V2 with process parameter settings in slicing software using a layer thickness of 0.30 mm, Top solid Layer 5, Bottom Solid Layer 5, Fill density 100%, cooling speed 100%, and flowrate 100%, nozzle temperature 205°C, and bed temperature 60°C. Variation in angle Part build Z-direction is proven to have a significant difference in Tensile strength with a difference of 10° resulting in a difference in Tensile strength of 15 MPa, where the highest tensile strength is 67.50 MPa with part build Z-direction at an angle of 80°, and the lowest tensile strength of 52.50 MPa with a Z-direction part build angle at an angle of 70°.

Assessment of maximal inspiratory and expiratory pressures in skeletal Class II patients with different growth patterns.

To evaluate maximal inspiratory (MIP) and expiratory (MEP) pressures, which are reflective of respiratory muscle strength, in skeletal Class II patients with different growth patterns (horizontal, average, and vertical) and to correlate those with airway dimension. Patients with a Class II skeletal base seeking orthodontic treatment were assigned to the following groups: average, horizontal, and vertical growth pattern. The control group (n = 14) comprised patients with a Class I skeletal base and average growth pattern. Airway dimensions were obtained using cone-beam computed tomography scans, and a spirometer with a pressure transducer was used for assessment of MIP and MEP. Routine spirometry for assessment of lung function was also performed. No significant differences were found in maximal inspiratory and expiratory pressures for the study groups in comparison with the control group. Class I patients had significantly greater oropharyngeal and nasopharyngeal airway volumes compared with the study groups. No significant difference in minimal cross-section area of the airway was observed among groups. A weak positive correlation between maximal inspiratory pressure and airway volume was observed. Although Class I patients displayed significantly greater oropharyngeal and nasopharyngeal airway volumes, there was no significant difference in respiratory muscle strength or airway function between Class II patients with different growth patterns and the Class I control group. The findings underscore the significance of exploring factors beyond craniofacial growth patterns that may contribute to sleep-related breathing disorders.

Comparative analysis of self-cure and dual cure-dental composites on their physico-mechanical behaviour.

Clinical practitioners may have become familiar with the rapid transformation of dental composites. However, they may not scientifically understand the factors influencing the mechanical and physical properties. Scientific knowledge of filler-resin interaction can significantly improve clinical understanding of resin composites. Several independent studies have examined the mechanical and physico-mechanical properties of dental resin composites; however, no comprehensive study has examined the influence of fillers and resin materials on the physico-mechanical properties of both self-cure and dual-cure composites. This study performed investigations on the physico-mechanical behaviour of four commercially available dual-cure dental composites (Bioactive, Fill Up!, Surefil One, Cention N) and two commercially available self-cure dental composites (Stela Capsule and Stela Automix). Test specimens for flexural and compressive strength, microhardness, fracture toughness, and hydrolytic behaviour were prepared and tested as per respective standards. The data sets were statistically analysed using one-way ANOVA and Tukey's post-hoc comparison. There was a substantial variation in flexural strength and modulus values in this study, ranging from 32.0 to 113.4 MPa and 2.36 to 12.07 GPa, respectively. Similarly, there were significant differences in compressive strength between the materials in this study, ranging from 119.3 to 223.5 MPa. The highest fracture toughness value was found to be 1.41 MPa.m0.5, while the lowest value was 0.43 MPa.m0.5. Variations in surface microhardness were significant (24.11-68.0 N/mm2), which correlated with the filler content. Water sorption and solubility demonstrated high variations among materials, with Surefil One exceeding ISO 4049 thresholds significantly. A linear correlation can be established between surface microhardness (HV) and flexural and compressive moduli, as well as filler content (wt.%). However, both flexural and compressive strengths are impacted by the resin's constituent monomers and the resin-filler matrix's cross-linking capability. Additionally, factors such as filler size, shape, and the cross-linking ability of the resin-filler matrix play a crucial role in fracture toughness and the propagation of cracks within the restoration. Also, resin monomers and filler particle size affect the hydrolytic degradation characteristics of composites, which can also affect their mechanical properties. © 2023 Australian Dental Association.

Musculoskeletal, Functional and Performance Impairment in Female Overhead Athletes with a Previous Shoulder Injury.

Shoulder injuries are substantial problems in overhead athletes, and more studies are necessary to deepen the knowledge on this type of injury. The objective of this study was to compare the overall function and performance of female overhead athletes with and without a previous history of shoulder injuries. In this cross-sectional study, female overhead athletes with and without a previous shoulder injury were included. Muscular impairment, the stability of the shoulder, strength, scapular dyskinesia, functionality and sports performance were evaluated. A total of 50 females were included. There were significant differences in strength (p = 0.046) and stability (p = 0.039) between groups, with a poorer score in the group with a history of shoulder injury. Regarding scapular dyskinesia, significant differences were also observed between groups (p = 0.048), with higher levels of dyskinesia in the group with previous shoulder injury. Also, muscular impairment showed significant differences between groups for the three muscles evaluated (p < 0.005). Additionally, the group without a previous shoulder injury presented with a significantly greater score in functionality (p = 0.046) and sports performance (p = 0.004). In conclusion, previous shoulder injuries are an important factor to take into account in female overhead athletes. Players with a history of shoulder injury present clinical impairments during the game, leading to poorer functional status and performance in sport.

FACTORS ASSOCIATED WITH HAND GRIP STRENGTH AMONG OLDER ADULTS—FINDINGS FROM THE LASI STUDY INDIA

Abstract Objective To identify the factors associated with handgrip strength among older adults in India. Methods Data for the study were drawn from the baseline survey of Longitudinal Ageing Study in India (LASI, 2017–18). This study was conducted on respondents aged 60 years and above with a total sample of 27,347 older adults (men-13,241 and women-14,118). The study assessed handgrip strength using a handheld Smedley’s Hand Dynamometer. Descriptive statistics and independent t-test was used to measure the mean difference in the handgrip strengths according to presence of risk factors. Results The mean handgrip strength was 29.76 + 11.23 kgs for both the genders. There was statistically significant difference in the mean handgrip strength of men (36.26 + 10.83 kg) and women (23.70 + 7.65 kg respectively). Significantly lower handgrip strength was observed among participants in rural area (29.58 + 11.20 kg), difficulty in activities of daily living (28.24 + 10.97 kg), low level physical activity, balance impairment (21.09 + 8.83 kg) slowness in walking (25.14 + 9.87 kg), history of falls (28.24 + 10.97 kg), and presence of bone and joint disease (27.44 + 10.60 kg) as compared to their counterparts. Conclusion The study contributed to a better understanding of factors associated with HGS, and thus, the HGS is recommended as a section in the health evaluation among high-risk older adults as the strategy of disease control and prevention.

Evaluation of Sealer Remnants Using a Bioceramic Sealer Single-cone Technique after Post Space Preparation and its Influence on the Adhesion of Fibre Posts in vitro.

To compare calcium silicate-based endodontic sealer and epoxy resin-based sealer remnants on root canal walls after post space preparation and their influence on the bond strength of fibre posts fixed with a dual-cured resin cement. Thirty-six extracted single-root mandibular premolars were instrumented and divided randomly into two equal groups with different endodontic sealers. iRoot SP (Innovative BioCeramix, Vancouver, Canada) was employed in the experimental group and AH Plus (Dentsply Sirona, Charlotte, NC, USA) was used in the control group. Sealer remnants were observed under an endodontic microscope after root canal therapy and post space preparation. Fibre posts were fixed with dual-cured resin cement. Specimens were taken at each third of the post space. The push-out bond strength was measured using a universal testing machine and fracture modes were assessed. Statistical analysis was performed using an independent samples t test and one-way analysis of variance. There was no statistically significant difference in bond strength of fibre posts between the control and experimental group (P > 0.05); however, sealer remnants were observed in 38.9% of the samples treated with iRoot SP and none of the samples treated with AH Plus. The major fracture mode in samples treated with iRoot SP was adhesive failure between the resin cement and the post, and no adhesive failure between the resin cement and dentine occurred at the site of the sealer remnant. The presence of iRoot SP remnants on the root canal walls after post space preparation did not interfere with bonding. iRoot SP is a viable option for root canal obturation before fibre post cementation.

SOCIAL ISOLATION AS A RISK FACTOR FOR GRIP STRENGTH DECLINE: FINDINGS FROM THE NHATS STUDY

Abstract Low grip strength is associated with negative health outcomes among older adults, including poor physical performance, sarcopenia, and all-cause mortality. Social isolation has been also linked with decreased physical function and mortality. Limited studies examined whether social isolation is a risk factor for grip strength decline among older adults and whether race differences exist in this association using population-based longitudinal data. The aim of this study was to evaluate the relationship between social isolation and grip strength among older adults and whether the relationship varies by race and over time. We analyzed National Health and Aging Trends Study (NHATS) data (2015 - 2018) and the sample included 4877 adults &amp;gt; 65 years old. Grip strength was measured using a digital hand dynamometer. Social isolation was measured using six NHATS items from the literature and the composite score ranged from 0 to 6, with a higher score indicating more isolation. The sample mean age was 75 (SD = 22; 68 - 110 years). Repeated-measures analysis of variance showed significant differences in grip strength across social isolation scores (p = .001) indicating that socially isolated older adults have significantly lower grip strength. We also found that grip strength significantly decreased by 2.046 kg over the four-year period (p = &amp;lt; .001). The findings showed no significant difference in grip strength across race and change in grip strength across time did not differ by race and social isolation. Interventions to improve muscle strength and reduce social isolation among older adults are needed.

Investigation of the Effects of Remote Online Exercise Training in Individuals Self-Isolating at Home Due to COVID-19 Disease: A Randomized Controlled Study

Objective: Effectiveness of a 4-week telerehabilitation program including thoracic expansion exercises (TEE), non-specific general body exercises (NSGBE), and physical activity recommendations (PAR) which started at quarantine in individuals with acute mild-COVID-19 was investigated in current study. Methods: This is a randomized controlled study which was performed between May 2021 and February 2022. Adult individuals with acute mild-COVID-19 were randomly grouped as training (TG) (telerehabilitation program under supervision for 3 days/week) and control (CG) (home program including TEE and PAR). Dyspnea (Modified Borg Scale and Modified Medical Research Council Dyspnea Scale), chronic fatigue (Checklist Individual Strength Questionnaire), anxiety and depression (Hospital Anxiety and Depression Scale), balance (Berg Functional Balance Scale) and lower body strength (a 30-s chair stand test) were evaluated remotely in the individuals before and after a 4-week follow-up. Results: Baseline characteristics and balance scores were similar between groups (p&gt;0.05). After 4-week from baseline, there were no significant differences in dyspnea, chronic fatigue, anxiety, depression, balance, and lower body strength between the groups (p&gt;0.05). However, as dyspnea, chronic fatigue, anxiety, and depression scores decreased, lower body strength increased significantly within TG after follow-up (p&lt;0.05). Dyspnea, chronic fatigue, and anxiety scores decreased while lower body strength increased significantly within CG after follow-up (p&lt;0.05). Conclusion: Dyspnea, severe fatigue, anxiety, and depression are commonly observed in individuals with mild-COVID-19 in the acute period. In these individuals, dyspnea perception, chronic fatigue, anxiety, depression, and functional performance improve after a 4-week light-intensity online tele-program applied either supervised or unsupervised. Mild exercises and PAR are safe and effective in these individuals.

The Effect of Sintering on Zirconia Manufactured via Suspension-Enclosing Projection Stereolithography for Dental Applications: An In Vitro Study.

Zirconia is a widely used material in the dental industry due to its excellent mechanical and aesthetic properties. Recently, a new 3D printing process called suspension-enclosing projection stereolithography (SEPS) was introduced to fabricate zirconia dental restorations. However, the effect of the sintering time and temperature on the properties of zirconia produced via SEPS has not been fully investigated. Zirconia slurries were prepared with varying percentages of zirconia powders and 3D printing resins, and 5Y-TZP (5 mol% yttria-stabilized zirconia) (n = 40) and 3Y-TZP (3 mol% yttria-stabilized zirconia) (n = 40) bar specimens were fabricated via SEPS manufacturing. The specimens were sintered at different temperatures and dwell times, and their flexural strength, density, and phase composition were measured. The viscosity of the slurries was also measured. Statistical analysis was performed using Welch's ANOVA and Kruskal-Wallis tests to evaluate the impact of the sintering conditions. Significant differences in flexural strength (p < 0.01) were observed between the 5Y-TZP samples, with those sintered at 1530 °C for 120 min showing an average strength of 268.34 ± 44.66 MPa, compared to 174.16 ± 42.29 MPa for those sintered at 1450 °C for 120 min. In terms of density, significant differences (p < 0.01) were noted for the 3Y-TZP specimens, with an average density of 6.66 ± 0.49 g/cm3 for samples sintered at 1530 °C for 120 min, versus 5.75 ± 0.55 g/cm3 for those sintered at 1530 °C for 10 min. X-ray diffraction confirmed the presence of a predominantly tetragonal phase in both materials. Zirconia printed via SEPS manufacturing can be sintered at a higher temperature with shorter dwell times, thereby producing high density samples. Different sintering conditions can be used to fully sinter 3D-printed zirconia for potential dental applications.

FORÇA DE PREENSÃO MANUAL NÃO DIFERE ENTRE PESOS LIVRES OU MÁQUINAS EM IDOSOS: METANÁLISE

Introduction: The aging can lead to low levels of muscle strength, related to the emergence of diseases, physical limitations and an increase in premature death in the elderly. The handgrip strength test is a parameter to measure muscle strength, and strength training with free weights or machines are efficient to increase this outcome. However, these equipments differ in appearance, biomechanics and selection strategy within a periodization, which ends up generating questions in the scientific community regarding which one is more efficient for the outcomes that want to meansure. Objective: This study aimed to compare whether there is a significant difference in handgrip strength in strength training that used free weights or machines in elderly individuals through a systematic review and meta-analysis. Methods: This research followed the protocols and fulfilled all the requirements of Cochrane and The PRISMA Statement. The literature search was performed in the electronic databases Cochrane Library, EMBASE, MEDLINE/PubMed, SCOPUS, Web of Science and Science Direct, and searches were performed in the references of studies already published on the subject. Eligibility criteria included: full articles of clinical trials in English with elderly individuals able to practice physical exercises; interventions with strength training that compared free weights with machines; and assessment of pre- and post-training handgrip strength. Results: A total of 436 studies retrieved from the databases, two studies met the inclusion criteria for performing the systematic review and meta-analysis. Statistical analysis showed no significant difference between groups for handgrip strength (P = 0,56). There was no heterogeneity between the studies (P = 1,00). Conclusion: The conclusion of this study was that there was no significant difference in handgrip strength between strength training using free weights or machines in elderly. Level of Evidence I; Systematic Review and Meta-analysis.

Bond Strength of a Novel Universal Resin Cement to Dentin with or without an Adhesive Bonding Agent: An In Vitro Study.

The purpose of this study was to evaluate the bond strength and fracture mode of universal resin cement to dentin compared to self-adhesive and adhesive resin cement with and without an adhesive bonding agent. Seventy-two molar teeth were sectioned to expose coronal dentin, divided into three groups, and assigned to RelyX Universal (universal), RelyX Ultimate (adhesive), or RelyX Unicem 2 (self-adhesive) cements from 3M. The 3 groups were further subdivided into 2 subgroups of 12 specimens each, with or without the use of an adhesive bonding agent. Lithium-disilicate discs were bonded to the dentin surface using the cements, stored for 24 hours in distilled water, and subjected to 2,000 thermocycles before shear bond strength testing and fracture mode analysis. Significant differences in bond strength and fracture mode were found between groups based on cement or the use of a bonding agent. Both the universal and adhesive cements had significantly greater bond strengths to dentin with the use of a bonding agent versus no bonding agent. With the self-adhesive cement, there was no significant increase in bond strength to dentin with the use of a bonding agent. The novel universal resin cement had similar bond strengths to dentin as the adhesive cement with the use of a bonding agent, and similar bond strengths as the self-adhesive cement without the use of a bonding agent. The adhesively bonded universal cement had the greatest percentage of mixed and cohesive fractures. When greater adhesion is needed clinically, the novel universal resin cement may be used with an adhesive bonding agent. However, when less adhesion is needed, it could be used without a bonding agent in self-adhesive mode.

Influence of changes in pelvic anteversion during gait on walking ability and physical function in patients with adult spinal deformity: A cross-sectional study

Evaluation of gait posture using a three-dimensional motion analysis system (3DMAS) revealed that elderly patients with adult spinal deformity (ASD) experience pelvic anteversion while walking. The purpose of this study was to investigate the influence of changes in pelvic anteversion during gait on walking ability and physical function in patients with ASD. Fifty-four patients with ASD aged 50 years or older who were admitted to our hospital between March 2016 and December 2021 were included in the study. The 6-min walking distance (6MWD) was used to evaluate walking ability, and trunk and hip extensor strength were measured to evaluate physical function in the subjects. The 3DMAS was used to measure the subject's changes in pelvic anteversion during gait. After measuring the changes in pelvic anteversion, the median value of the study subjects was calculated, according to which the subjects were divided into two groups (small anteversion [S] group, large anteversion [L] group). Walking ability and physical function were compared between the two groups. The number of subjects in each group was 27. Comparisons of walking ability and physical function between the groups revealed significant differences in 6MWD (S group, 333.6±111.2m; L group, 238.0±106.3m) and hip extensor strength (S group, 15.8±3.8 kgf; L group, 13.4±4.4 kgf). No significant differences regarding trunk extensor strength were observed between the groups (S group, 15.2±4.0 kgf; L group, 12.9±4.8 kgf). The results of the present study revealed that ASD patients with greater pelvic anteversion associated with walking have lower walking ability and physical function. These results suggest the importance of evaluating the posture of ASD patients not only by using radiographic findings but also by assessing movement, such as gait posture.

Effects of Taekwondo Poomsae Training on Lower Limb Reaction Ability and Balance Performance in Adolescents

&lt;p&gt;背景：學習跆拳道運動有助於兒童與青少年成長與體適能表現，但學習跆拳道品勢的研究較少，因此本研究希望了解學習跆拳道品勢訓練後的身體適能表現。目的：探討從事8週跆拳道品勢訓練後，對國中少年下肢爆發力、反應能力與平衡能力的影響。方法：招募未有運動習慣及跆拳道訓練經驗之男性國中生16名，隨機分配實驗組 (n = 8)(參與學校體育課程+跆拳道品勢訓練)，控制組 (n = 8)(學校體育課程)，進行8週的訓練課程。訓練前後進行身高體重及腿長測量、動態平衡能力、反應能力及下肢爆發力的測驗，並以混合設計二因子變異數分析，比較兩組別反應能力與平衡能力之差異，當交互作用達顯著時，以LSD法進行事後比較。以獨立樣本t檢定考驗實驗組與訓練組進步百分比是否有達顯著性，並以皮爾森績差相關分析與受試者下肢平衡能力與反應能力的相關性。結果：實驗組與控制組在爆發力與平衡表現上組別因子上達到顯著差異 (p &lt; .05) 且實驗組與控制組進步百分比也達顯著差異 (p &lt; .05)。反應能力組別因子與時間因子未達顯著差異 (p &gt; .05)，進步百分比也未達顯著差異 (p &gt;.05)。訓練前反應能力與平衡表現為低度相關 (r = .352 , p = .10)，訓練後反應能力與平衡表現之間達中度相關 (r = .665，p &lt; .05)。結論：跆拳道品勢訓練可以顯著提升國中少年的下肢爆發力與下肢平衡能力。爆發力、反應能力、平衡表現進步幅度都大於控制組。訓練後反應能力與平衡表現之間存在相關性，可能是跆拳道品勢訓練提升了學童身體協調與感覺統合。未來可針對不同跆拳道訓練方式與不同年齡層了解訓練與身體發展的差異。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Background: Learning Taekwondo can contribute to the growth and physical fitness performance of children and adolescents. However, there is limited research on learning Taekwondo Poomsae. Therefore, this study aims to understand the impact of learning Taekwondo Poomsae on physical fitness performance. Purpose: The purpose of this study was to investigate the effects of 8 weeks of Taekwondo Poomsae training on lower limb explosive strength, reaction ability, and balance in junior high school adolescents. Methods: Sixteen male junior high school students with no prior sports experience or Taekwondo training were recruited. The participants were randomly assigned to either the experimental group (n = 8) (participating in school physical education classes plus Taekwondo Poomsae training) or the control group (n = 8) (participating only in school physical education classes). Both groups underwent an 8-week training program. Before and after the training, all participants underwent measurements of height, weight, leg length, dynamic balance ability, reaction ability, and lower limb explosive strength. The participants’ data were analyzed using a mixed-design two-factor analysis of variance to compare the differences in reaction ability and balance ability between the two groups. When the interaction effect was significant, post hoc comparisons were performed using the LSD method. Independent sample t-test was used to test the significance of improvement percentage between the experimental and control groups. Pearson correlation analysis was used to examine the relationship between lower limb balance ability and reaction ability. Results: The experimental group showed significant differences in explosive strength and balance performance compared to the control group (p &lt; .05). Moreover, the improvement percentages in both explosive strength and balance performance were significantly different between the two groups (p &lt; .05). However, there were no significant differences in reaction ability between groups or in the improvement percentage (p &gt; .05). Before the training, there was a low correlation between reaction ability and balance performance (r = .352, p =.10). After the training, there was a moderate correlation between reaction ability and balance performance (r = .665, p &lt; .05). Conclusion: Taekwondo Poomsae training can significantly improve lower limb explosive strength and balance in junior high school adolescents. The improvement in explosive strength, reaction ability, and balance performance was greater in the experimental group than the control group. The correlation between reaction ability and balance performance after training suggests that Taekwondo Poomsae training may enhance the students’ body coordination and sensory integration. Future studies could explore the differences in training and physical development across different Taekwondo training methods and age groups.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Evaluation of Shear Bond Strength and Microleakage of Self-adhesive Giomer

This study was aimed to evaluate the bonding performance of a self-adhesive giomer and compare it to a conventional flowable composite resin with regard to shear bond strength and microleakage in enamel and dentin. Healthy human premolars extracted for orthodontic treatments were used in the study. For shear bond strength tests, enamel and dentin specimens were prepared for the study group with selfadhesive giomer and for the control group with conventional flowable composite resin with a 5th-generation adhesive system. A universal testing machine was used to measure the shear bond strength. For the microleakage tests, specimens were immersed in a 2% methylene blue solution for 24 hours, cut into sections, and evaluated with a stereomicroscope for the extent of dye penetration. The results of the study showed no statistically significant difference in shear bond strength between the self-adhesive giomer and the conventional flowable composite resin in enamel (&lt;i&gt;p&lt;/i&gt; = 0.091). On the contrary, in dentin, the self-adhesive giomer showed significantly lower shear bond strength (&lt;i&gt;p&lt;/i&gt; &lt; 0.0001). The microleakage of the selfadhesive giomer was significantly higher than that of the conventional flowable composite resin (&lt;i&gt;p&lt;/i&gt; = 0.002). Self-adhesive giomer is considered useful for restoring small cavities at the enamel level of pediatric patients by reducing chair time with the advantage of a simple bonding process. However, as the study was conducted in a laboratory setting, further research in a clinical environment is deemed necessary.

In vitro performance of an autocured universal adhesive system in bonding to dentin

BackgroundThe successful integration of resin-based dental adhesives significantly impacts restorative dentistry, providing efficient and aesthetically pleasing caries treatments. Among various adhesives, one-step self-etching adhesives (1-SEAs) have gained popularity due to their simplicity and short application time. However, concerns have been raised regarding their bonding performance and marginal adaptation characteristics, which differ from two-step self-etching adhesives (2-SEAs) and three-step etch-and-rinse adhesives. Additionally, light-cured bonding materials may encounter challenges in deep cavities and inaccessible areas, necessitating extended light irradiation time. Autocured bonding materials are a potential solution, but limited comparative studies have been conducted on their performance.MethodsIn this in vitro study, we evaluated a new autocured universal bonding material (Bondmer Lightless 2) and compared the results with recent light-cured bonding materials. Microshear bond strength (μSBS) tests were performed on 25 human molars using five different combinations of adhesives and composite resins: Bondmer Lightless 2 with Estelite Bulk Fill Flow (BE group), Bondmer Lightless 2 with a prototype composite resin (BO group), Prime&Bond Universal with SDR flow + (PS group), Scotchbond Universal with Filtek Bulk Fill (SF group), and G-Premio Bond with Gracefil BulkFlo (GG group). The bond strengths and failure modes were assessed using a universal testing machine and scanning electron microscope (SEM), respectively. Marginal adaptation was evaluated using swept-source optical coherence tomography (SS-OCT) and confocal laser scanning microscopy (CLSM) on 40 sound bovine maxillary incisors.ResultsThe μSBS test showed no significant differences in bond strength among the tested groups. Most failure modes were observed at the bond interface between the adhesive and the dentin. The autocured bonding material demonstrated significantly higher marginal adaptation (SI%) than PS, SF, and GG. The CLSM images corresponded with gaps observed in the SS-OCT images, indicating improved marginal sealing in the autocured group.ConclusionsThe new autocured universal bonding material exhibited comparable bond strength to a conventional light-cured material while demonstrating a superior marginal adaptation level. This finding suggested that the autocured material could be a valuable alternative, especially when extended light irradiation would pose a challenge. Further clinical studies would be warranted to evaluate the performance of the autocured bonding material in actual restorative dental practice.

Synthesis and analyses of injectable fluoridated-bioactive glass hydrogel for dental root canal sealing.

This study aimed to synthesize fluoride-doped bioactive glass (F-BG) based thermo-sensitive injectable hydrogel for endodontic applications. The structural and phase analyses were done with Fourier Transform Infrared spectroscopy and X-ray Diffraction, respectively. The setting time of prepared injectable was investigated at 21°C (in the presence and absence of an ultrasonic scalar) and at 37°C. Flowability was tested according to ISO-6876:2012 specifications, whereas injectability was checked by extrusion method using 21-, 22-, and 23-gauge needles. The in vitro bio-adhesion and push-out bond strength were studied on days 7 and 90 and compared with the commercially available TotalFill®. The ion release profile was analyzed for up to 30 days with Inductively Coupled Plasma Optical Emission Spectroscopy. The fluoride release analysis was conducted periodically for up to 21 days in deionized water and artificial saliva using an ion-selective electrode. The final setting time at 21°C, 21°C+ultrasonic scalar, and 37°C were 38.66±3.21, 29.12±1.23, and 32±3.46 min, respectively. The flowability was 25±3.94 mm, and the injectability coefficient was ≥70.3 for 22, 21, and 57% in a 23-gauge needle. Fluoride release in deionized water was found to be significantly higher than in artificial saliva and increased with time. A significant difference in bond strength was found between days 7 and 90, where the strength was increased, and a new apatite layer was formed on the tooth surface. A rapid release of calcium, phosphate, and silicon ions was seen initially, whereby the continuous release of these ions was observed for up to 30 days. The prepared F-BG injectable hydrogel has shown promising results and has the potential to be used as an endodontic sealer.

Adhesive Bond Strength of Restorative Materials to Caries-Affected Dentin Treated with Antimicrobial Photodynamic Therapy: A Systematic Review and Meta-Analysis.

Objective: This systematic review aimed to evaluate the adhesive bond strength of restorative materials to caries-affected dentin (CAD) treated with antimicrobial photodynamic therapy (aPDT) in comparison with conventional chemical disinfectants. Methods: Three databases, including the Web of Science, Scopus, and PubMed, were searched to address the focused question: "What is the effect of aPDT compared to conventional chemical disinfection techniques on the adhesive bond strength of restorative materials to CAD?." Search keywords included "dentin*" "adhes bond*" "caries-affected dentin" "photodynamic "photochemotherapy" "photosensitizing agent" "phototherapy" "photoradiation" "laser" "light activated" "photoactivated." A fixed-effects model was used in each meta-analysis and the inverse variance was used to calculate the standard mean difference (SMD). For evaluating the statistical heterogeneity, the Cochrane's Q test and the I2 statistics were used. The risk of bias was evaluated based on the Cochrane Collaboration's tool. Results: Fourteen studies were included in the qualitative as well as quantitative analysis. The results of the meta-analyses exhibited an SMD of 2.38% [95% confidence interval (CI): 2.03-2.73; p < 0.00001], indicating a statistically significant difference in the shear bond strength scores between the tested group (samples treated with aPDT) and the control group (i.e., favoring the sound dentin and/or conventional chemical disinfectants). Contrarily, an SMD of -1.46% (95% CI: -2.04 to -0.88; p < 0.00001) and -0.37% (95% CI: -0.70 to -0.03; p = 0.03) was observed, indicating a statistically significant difference in the microtensile bond strength (μTBS), as well as microleakage scores between the tested group (favoring the samples treated with aPDT) and the control group (i.e., sound dentin and/or conventional chemical disinfectants). Conclusions: Adhesive bond strength of restorative materials to CAD treated with conventional chemical disinfectants showed superior outcomes compared to photodynamic therapy (aPDT).

Differences in Abdominal Muscle Thickness, Strength, and Endurance in Persons Who Are Runners, Active, and Inactive

Background: Core musculature is important for efficiency during activities including running. Both abdominal muscle strength and endurance contribute to this efficiency. The purpose of this study is to determine what differences and relationships exist in abdominal muscle thickness, strength, and endurance among persons who are runners, active, and inactive. Hypothesis: Persons in the running group would show significantly greater abdominal muscle thickness, muscle strength, and muscle endurance compared with those in the nonrunning groups. Study Design: Quantitative cohort design. Level of Evidence: Level 2b. Methods: A total of 78 subjects aged 18 to 27 years were divided into 3 groups: runners, active, and inactive. Assessment included abdominal muscle thickness via diagnostic ultrasound (Mindray North America), strength using a static Isotrack dynamometer (JTech Medical), and abdominal muscle endurance using a side plank. Statistical analysis using analysis of variance, t tests, and Pearson’s correlation coefficients and partial correlations was performed using SPSS Version 26 with a significance level of P &lt; 0.05. Results: Significantly greater muscle thickness of internal obliques (IOs) at rest and during contraction was found in the running group compared with the active group, the active group compared with the inactive group, and the running group compared with the inactive group. There were no statistically significant differences in overall strength measured by dynamometry among the 3 groups. Plank time was significantly greater for the running group compared with the other 2 groups. Male participants were greater in all areas: strength, plank time as a measure of muscle endurance, and muscle thickness. Body mass index was significantly correlated with resting thickness, muscle endurance, and muscle strength. Conclusion: Persons who run, are active, and are inactive use their abdominal muscles differently. Runners have thicker IOs and better abdominal muscle endurance than the other 2 groups. Focusing on endurance training of the obliques may be beneficial for persons who run. Clinical Relevance: This research could contribute to developing core training programs to ensure runners target the correct abdominal muscles with the best type of training.

Fluoridated orthodontic adhesives: Implications of release and recharge and their impact on shear bond strength in demineralized tooth surfaces.

This study measured fluoride release from a light-cured orthodontic adhesive resin (Vega type) at three time intervals (one day, one week, and one month), investigated the rechargeability of the resin, and assessed its impact on shear bond strength in demineralized tooth surfaces. This study used 30 recently extracted upper premolar teeth to explore the effects of fluoride release over specific time intervals. The teeth underwent demineralization and were categorized into groups based on time intervals: one day, one week, and one month. Subgroups within each interval underwent fluoride recharging through fluoride varnish application. Fluoride release and shear bond strength were assessed after etching with phosphoric acid gel, applying the orthodontic adhesive, and curing. The samples were stored in deionized water. Fluoride quantification used a selective electrode, while shear bond strength assessment employed a universal testing machine. Finally, statistical analysis of the data was performed using SPSS 22. The study found that after one month, the adhesive had the highest fluoride release and shear bond strength mean values. There were significant differences in fluoride release and shear bond strength between the various groups studied. The application of fluoride varnish around the orthodontic bracket resulted in a positive effect on the shear bond strength of the bracket.

Prefrontal cortex functional connectivity changes during verbal fluency test in adults with short-term insomnia disorder: a functional near-infrared spectroscopy study.

Individuals suffering from short-term insomnia disorder (SID) experience difficulties in falling or staying asleep, often leading to daytime fatigue and impaired concentration. However, the underlying mechanisms of SID remain unclear. This study aims to investigate the alterations in brain activation patterns and functional connectivity in patients with SID. The study enrolled a total of 31 adults diagnosed with SID and 31 healthy controls (HC). Functional near-infrared spectroscopy (fNIRS) was utilized to assess the concentrations of oxyhemoglobin (Oxy-Hb) and functional connectivity in the prefrontal cortex of each participant while performing the verbal fluency test (VFT) task. In the VFT task, no significant difference was found between the SID group and the HC group in terms of integral values, centroid values, and mean Oxy-Hb variations. These findings suggest that both groups exhibit similar hemodynamic responses. However, the functional connectivity analysis revealed significant differences in inter-channel connectivity strength between the two groups. The SID group showed significantly lower average inter-channel connectivity strength compared to the HC group. Moreover, six channel pairs (right frontopolar cortex - left frontopolar cortex, left orbitofrontal cortex - left temporopolar cortex, left temporopolar cortex - left frontopolar cortex, left frontopolar cortex-Ch38, left frontopolar cortex - right pre-motor and supplementary motor cortex, and left frontopolar cortex - right dorsolateral prefrontal cortex) exhibited significantly higher connectivity strength in the HC group compared to the SID group (FDR corrected, p < 0.05). Specifically, channel 27 exhibited the highest frequency of significant connectivity across different channel pairs, occurring five times in total. The channel pair Ch27-Ch39, representing left frontopolar cortex and right dorsolateral prefrontal cortex, exhibited a negative correlation with PSQI scores (r = -0.422, p = 0.018). Our findings suggest that patients with SID may exhibit altered brain connectivity during the VFT task, as measured by fNIRS. These results provide valuable insights into the functional brain differences associated with SID. Further research is needed to validate and expand upon these findings.