BDJ Open最新文献

Objective: To evaluate the impact of salbutamol sulfate inhalation on the surface roughness and color stability of hybrid ceramics using an inhaler and nebulizer at different doses over three time periods.

Materials and methods: A total of 120 samples of Lava Ultimate (LU), Cerasmart (CS), and Nacera Hybrid (NH) were divided into three equal groups. Each group was subdivided into two subgroups according to the use of inhaler or nebulizer. Each subgroup was subdivided into two divisions according to the minimum and maximum doses of inhalation. The samples were cut rectangular and polished according to the manufacturers' instructions. They were exposed to salbutamol in acrylic boxes and then kept in artificial saliva for 30, 60, and 90 days which was equivalent to 4, 8, and 12 months. The surface roughness and color change (ΔE) were measured before and after exposure to salbutamol via a non-contact profilometer and a reflective spectrophotometer based on CIE L*a*b* respectively. The data were tabulated and statistically analysed using a three-way ANOVA test and the significance level was set at P ≤ 0.05.

Results: Cerasmart recorded the highest statistically non-significant roughness change (1.2298 ± 0.331%, P > 0.05). NH had the highest statistically significant ΔE (ΔE = 6.174, P ≤ 0.0001). The maximum dose used in three-month exposure period had the highest statistically significant change in roughness and color (P ≤ 0.0001). Additionally, the inhaler-treated groups presented significantly higher values than the nebulizer-treated groups for ΔE only (P < 0.05). Eventually, Pearson correlation analysis revealed a statistically significant positive direct relationship between roughness and ΔE (P = 0.013).

Conclusions: Salbutamol can significantly affect the color of hybrid ceramics while causing a non-significant increase in their surface roughness.

Aim: Oral functions related to eating, including mastication, swallowing, and taste, are fundamentally a multisensory experience that relies on the crossmodal interaction of touch, gustation, temperature, pain, and proprioception. The brain mechanisms of oral multisensory processing related to eating have remained unknown.

Methods: The current systematic review summarizes the findings from neuroimaging studies (mainly functional magnetic resonance imaging) focusing on the interaction of multiple sensory stimuli in human participants. Neuroimaging studies of human adults on the interaction between multiple sensory stimuli related to oral functions were identified and extracted via three electronic databases and reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Results: Thirteen primary studies were eligible to be included in this review. Five studies investigated the interaction of intraoral (i.e., sensorimotor, taste, and noxious) stimuli. Six studies investigated the interaction between intraoral and extraoral (i.e., auditory, olfactory, and visual) stimuli. One study investigated the audio-visual interaction on dental fear, and another study investigated sensorimotor processing of eating tools. The studies showed great diversity in the experimental design of crossmodal interaction. Regarding the brain features related to the interaction, the somatosensory and motor regions were mostly reported in the studies.

Conclusions: The systematic review revealed a complex pattern of brain activation of oral multisensory processing, which can be attributed to the diversity in the experimental design of crossmodal interaction. The findings highlight the role of multisensory integration in maintaining oral health.

Objectives: The push-out bond strength to the intraradicular dentin was evaluated in this in vitro study using an epoxy-based endodontic sealer loaded with silver-gold nanoparticles. Additionally, the benefits of using the nanoparticles as a canal pretreatment before applying the sealer were evaluated in comparison to using the sealer alone.

Methodology: After being decoronated and instrumented, thirty extracted human central incisors were obturated and then divided horizontally into three parts (coronal, middle, and apical) with a thickness of 2 mm. Three groups of slices were created at random: Groups I (control) and II received AH Plus sealer, AH Plus sealer loaded with silver gold nanoparticles, and III received nanoparticles as a pretreatment for the canal prior to gutta-percha and AH Plus sealer for obturation. The specimens were loaded at a rate of 0.5 mm/min utilizing a Universal Test Machine and put through a push-out test. Statistics were applied to each data collection. Additionally, the significance level was set at P ≤ 0.05.

Results: A push-out test showed that the groups differed significantly from one another. The tested groups differed significantly in both the coronal and middle portions, with group (II) exhibiting the highest push-out strength values. Group (II) had the highest push-out strength values in the apical portion (3.66 ± 0.72), followed by group (III) (2.90 ± 1.45), while group (I) had the lowest value (2.88 ± 1.73). There was no significant difference between the groups.

Conclusions: the experimental AH Plus sealer combined with silver-gold nanoparticles demonstrated the most effective adhesion followed by nanoparticles as a canal pretreatment prior to sealer application when compared to AH Plus sealer alone.

Introduction: Journal clubs are integral to continuing medical education, promoting critical thinking and evidence-based learning. However, inconsistent engagement, reliance on faculty expertise, and the complexity of research articles can limit their effectiveness. Generative Artificial Intelligence (Gen AI), particularly Large Language Models (LLMs) offers a potential solution, but general-purpose LLMs may generate inaccurate responses ("hallucinations"). Retrieval-Augmented Generation (RAG) mitigates this by integrating AI-generated content with curated knowledge sources, ensuring more accurate and contextually relevant responses. This study explores the development and preliminary evaluation of a RAG-enhanced LLM to support journal club discussions.

Materials and methods: A specialized LLM was deployed using Microsoft Azure's GPT-4o. A vector database was created by embedding journal club articles using text-embedding-ada-002 (Version 2) for efficient information retrieval. A dedicated website provided user-friendly access. The study followed a design-based research (DBR) approach, engaging residents and faculty who interacted with the LLM before and during journal club sessions. Data collection included focus group discussions (FGDs) and questionnaires assessing engagement, usability, and impact.

Results: The study involved a total of 13 residents and three faculty members as participants. 50% of residents reported a positive experience, while the rest had a neutral response, citing both advantages and limitations. The LLM improved article summarization, query responses, and engagement as reported by residents. Moreover, the faculty observed enhanced discussion quality and preparation whereas overall challenges included the need for precise prompts and occasional misleading responses.

Conclusion: The study highlights the potential of a RAG-enhanced LLM to improve journal club engagement and learning. Future advancements in AI and open-source models may enhance accessibility, warranting further research.

Introduction: Early enamel demineralization can be reversed through remineralization, which restores lost minerals to strengthen enamel and prevent decay.

Aim: This study evaluated the remineralization efficiency of three commercial treatments on artificially demineralized primary enamel.

Methods: Forty exfoliated primary anterior teeth were demineralized and divided into five groups: untreated control, artificial saliva, fluoridated toothpaste, Curasept toothpaste, and BioMin toothpaste. The treatments were applied for 28 days. Remineralization efficacy was assessed using Vickers microhardness testing, surface roughness measurement, and Scanning electron microscope combined with EDX (SEM-EDX). One-way ANOVA and Tukey's HSD test were used for statistical analysis.

Results: Microhardness and surface roughness tests confirmed BioMin's superior remineralization potential. Scanning electron microscopy showed that untreated enamel exhibited extensive demineralization, whereas treated groups displayed varying degrees of remineralization. BioMin demonstrated the highest calcium, phosphate, and fluoride incorporation, followed by Curasept and fluoridated toothpaste. The artificial saliva group showed no significant improvement over the control.

Conclusion: BioMin, followed by Curasept and fluoridated toothpaste, effectively remineralized demineralized enamel. BioMin's bioactive glass formulation provided the highest mineral gain, suggesting its potential for non-invasive enamel restoration in pediatric dentistry.

Objectives: to compare the effect of using a pre-reacted glass-ionomer (PRG) barrier coat versus silver diamine fluoride (SDF) varnish treatment before orthodontic bracket bonding to prevent white spot lesions (WSL). The effect of these materials on the shear bond strength of orthodontic brackets was evaluated through an in vitro study.

Methods: One hundred-five premolars were used; forty-two specimens were designated for comparing SDF versus PRG-barrier coat using a scanning electron microscope (SEM) with elemental analysis and microhardness testing (n = 21/group). Tested materials were applied in a split-tooth design protocol (side A: control, side B: treated). Measurement was made at baseline and after bracket placement and exposure to the pH cycle. A polarized light microscope (PLM) was used for qualitative examination. Sixty-three specimens were intended for shear bond strength (SBS) testing after the pH cycle as follows: control group (no treatment), SDF group, and PRG-barrier coat group (n = 21/group). Statistical analysis was done using Paired T-test.

Results: SEM for specimens treated by SDF or PRG revealed enamel remineralization with calcium deposits and small porosities between the crystallites. All groups had a significant difference regarding the Ca/P ratio and microhardness. Baseline hardness for both groups was significantly higher than the treated sides, which was significantly higher than the non-treated sides (P = 0.000*) and (P = 0.000*) in accordance with the Paired T-test. In comparing SDF with PRG-coat groups, the T-test showed non-significant differences in mean differences between treated and baseline hardness values (T = 0.32, P = 0.74). PLM for treated specimens by SDF or PRG depicted an evident remineralized surface enamel layer. SBS values did not differ significantly between groups.

Conclusions: As confirmed by SEM and PLM, applying either SDF varnish or PRG-barrier coat before bonding orthodontic brackets could effectively prevent the development of WSL and achieve surface enamel protection. In addition, the two applied varnishes showed slightly higher shear bond strength of orthodontic brackets compared to the control group, with the SDF slightly higher than PRG. Also, clinical translation is needed in future research to evaluate the study.

Objective: The purpose of this study was to compare the effectiveness of low and high magnifications in detecting occlusal caries in permanent posterior teeth using the International Caries Detection and Assessment System (ICDAS) II criteria through the ICDAS e-learning program.

Materials and methods: Forty extracted permanent posterior teeth were used. Two examiners received e-learning training on the ICDAS webpage for detecting occlusal caries before visual examinations. Visual inspections were performed under ×2.5 magnification with a magnifying loupe and ×25 magnification with a dental surgical microscope within a week. The ICDAS scores assigned by both examiners were validated by an ICDAS expert. The visual assessment results were compared with the histological analysis results using Downer's criteria as the gold standard.

Results: Inter-examiner reliability for ICDAS-II scoring at low magnification (×2.5 loupe) and high magnification (×25 operating microscope) was moderate. However, the lenient (binary) criteria showed substantial agreement at both magnifications. Specificity was highest for both the low and high treatment thresholds (88.2% and 81.5%, respectively) at low magnification, whereas sensitivity peaked at high magnification for the high treatment threshold criterion (91.7%). Image-based ICDAS scoring by an expert also demonstrated good diagnostic accuracy (76.9%), though it was not superior to ICDAS scoring performed under ×2.5 magnification (82.1%).

Conclusion: The ICDAS-II score, particularly the lenient criterion, demonstrated a strong correlation with histological depth. The e-learning program effectively equips dentists with diagnostic skills. Extreme magnification resulted in the overestimation of dental caries, whereas low magnification (2.5x) resulted in greater diagnostic accuracy.

Aim of the study: This study aims to evaluate the effectiveness of a 980-nm diode laser in inducing mineral trioxide aggregate (MTA) nanoparticle precipitation on root canal dentin surfaces for dentinal coverage.

Materials and methods: Sixty mature single-rooted teeth were decoronated at a fixed length of 16 mm and instrumented to size #40/0.04. Canals were filled with either distilled water or nanoMTA suspension and randomly divided based on the treatment modality into: G I and G II flooded with distilled water and laser irradiated at 2 Watt and 4 Watt respectively, GIII and GIV flooded with nanoMTA suspension and laser irradiated at 2 Watt and 4 Watt respectively, G V, flooded with nanoMTA suspension without laser irradiation, and G VI flooded with distilled water without laser irradiation. All samples were longitudinally split and scanned by environmental scanning electron microscopy (ESEM) to evaluate dentinal tubule (DT) occlusion and MTA surface precipitation. Image J analysis software was used to quantify open DTs, while a scoring system assessed dentine coverage.

Results: Laser irradiation significantly enhanced nanoMTA precipitation and dentinal tubule occlusion. The highest dentinal surface coverage, indicated by the lowest pixel percentage, was in laser-irradiated nanoMTA suspension groups G IV (3.4 ± 3.1) and G III (16.7 ± 3), while the lowest coverage was in the non-irradiated saline group G VI (53.4 ± 9.6) (p < 0.05). Median dentinal coverage scores were also highest in G III and G IV (both = 4). G VI showed the least dentinal occlusion, with a statistically significant difference from other groups (p < 0.05).

Conclusion: The 980-nm diode laser effectively enhances MTA nanoparticle precipitation on root canal surfaces, improving dentinal tubule occlusion and sealing potential. Further research is warranted to optimize laser parameters, MTA suspension ratios and to assess clinical outcomes.

Background: Climate change poses a serious threat to the planet, mainly driven by greenhouse gas (GHG) emissions. Dental laboratories contribute to GHG emissions through staff travel, waste, energy and water consumption, and procurement. Carbon footprinting is the process of quantifying the direct and indirect GHG emissions associated with a service. This study aimed to assess the Carbon Footprint (CFP) of private dental laboratories in Egypt.

Materials and methods: Data were collected from private dental laboratories in Cairo, Alexandria, and Elbeheira, Egypt in August 2024 through interview questionnaires. A CFP calculator was used to estimate carbon emissions from staff travel, waste, energy and water consumption, and procurement. The data of all laboratories was summed and divided to determine the average CFP per laboratory and per prothesis/appliance, both with and without the depreciation of dental equipment.

Results: Data from 21 dental laboratories were collected. An average private dental laboratory in Egypt worked 309 days with a staff of around 7 persons and makes around 7119 prostheses/appliance per year. The CFP of dental laboratories was around 20,820 kg CO₂e, equal to 2.9 kg CO₂e per prosthesis/appliance. The largest contributor to the CFP was staff travel (43.6%), followed by procurement (27.8%), energy consumption (25%), waste (3.3%), and water consumption (0.1%). After including the depreciation of dental equipment, the CFP increased by 7.7%.

Conclusion: Private dental laboratories in Egypt produce a significant amount of carbon emissions. Staff travel was the major contributor to the carbon emission because each laboratory hired several couriers to deliver the prostheses/appliances and impressions. The CFP of electricity consumption was significant, likely because the air conditioning ran throughout the year to cool the machines down. Future studies are needed to develop customized country-specific CFP calculators to accurately measure the carbon emissions of dental laboratories in various settings. Preventing oral diseases, educating technicians on sustainable dental practices, optimizing public transportation, using bulk delivery services, shifting to renewable energy, and adopting circular economy are essential to mitigate the carbon emissions of dental laboratories.