The Effect of Formulated Dentin Remineralizing Gel Containing Hydroxyapatite, Fluoride, and Bioactive Glass on Dentin Microhardness: An In Vitro Study.

Objectives: This study aimed to develop a gel with dentin-remineralizing properties, integrating nano-hydroxyapatite (nHA), sodium fluoride (NaF), and bioactive glass (BG). Materials and Methods: The enamel layer of 40 bovine incisors was removed. The samples were allocated into four groups of 10 each, based on varying concentrations of nHA, BG, and NaF in the gel compositions (wt%): (1) 2.5%-7.5%-0.05%, (2) 5%-5%-0.05%, (3) 7.5%-2.5%-0.05%, and (4) a control group with a base gel lacking remineralizing agents. After 8 hr of demineralization, the dentin surface microhardness was measured at depths of 30, 60, and 140 µm. After a 20-day pH cycling, the percentage of surface microhardness recovery (SMHR%) was measured and compared among the groups using the ANOVA and Tukey HSD post hoc tests (α = 0.05). Scanning electron microscopy analysis evaluated each specimen's superficial morphology. Results: At all depths, the SMHR% of the Group 2 and Group 3 was significantly higher than the control group (p < 0.05). The SMHR% Group 1 (67.39% ± 29.34%) was significantly higher than the control group (-21.24% ± 51.72%) only at the depth of 30 µm (p = 0.047). Group 3 had higher SMHR% than Group 2 at all depths; however, the difference was not statistically significant. Moreover, the SMHR% of Group 3 was significantly higher than that of Group 1 at depths of 30 µm (187. 94% ± 68.95% vs. 67.39% ± 29.34%; p = 0.005) and 60 µm (179.55% ± 75.96% vs. 64.34% ± 41.96%; p = 0.043). Surface deposition and tubule occlusion were observed in the Groups 2 and 3 samples, which was more prominent in the latter. Conclusions: Combining 7.5% nHA, 2.5% BG, and 0.05% NaF could potentially remineralize primary carious lesions.

Content analysis of fluoride-related posts on Instagram.

BACKGROUND: The Internet and social media have become many people's primary sources of health information. Instagram is one of the most popular social media platforms, and users spend a significant amount of time daily on the platform. Therefore, analyzing oral health-related information shared online can help to identify the requirements of specific groups, assisting in the planning and execution of educational public health actions. As a result, this study was carried out to conduct a qualitative evaluation of fluoride-related content on Instagram in 2022-2023. METHODS: Using hashtags associated with fluoride, a search was conducted on the Instagram application in the Persian language. All fluoride-containing posts were saved, and data was collected thrice at two-month intervals. MAXQDA software version 2020 was used to categorize the collected data content based on type, quality, and quantity. RESULTS: The qualitative analysis included 1565 (9.45%) posts with fluoride-related content out of 16,475 total posts. After removing the duplicates, 400 posts remained, among which 282 posts (70.5%) and 118 posts (29.5%) were pro- and anti-fluoride, respectively. After qualitative analysis, 270 codes were examined and categorized into three main themes and eight subthemes: "fluoride sources," "The advantages and disadvantages of fluoride," and "Invalid beliefs about fluoride." CONCLUSION: The frequency of pro-fluoride use was higher than anti-fluoride posts. However, due to the high prevalence of posts containing false information on fluoride toxicity for health, ineffectiveness on caries prevention, and conspiracy theories, there is a need to improve the quality of information on fluoride by providing scientific and unbiased explanations by professionals online or during dental visits and supervising social media content.

Hypnosis and nitrous oxide impact on the school aged patients' anxiety and cooperation candidate for tooth extraction: A randomized clinical trial.

Background: This randomized clinical trial (RCT) investigated whether hypnosis would lead to favorable outcomes in reducing anxiety, enhancing cooperation, and improving physiological responses in school-aged children undergoing tooth extraction compared to nitrous oxide/oxygen (N2O/O2) and conventional behavior guidance (CBG). Methods: Sixty-six school-aged children (mean age: 7.87 ± 1.18 years) who needed one posterior primary tooth extraction were included. Children with low-to-moderate anxiety were randomly divided into three groups (n = 22 each): hypnosis, N2O/O2, and CBG. Anxiety levels during and after anesthetic injection and tooth extraction were assessed using the Venham Clinical Anxiety Scale (VCAS) and the Venham Picture Test (VPT). Changes in heart rate (HR) and oxygen saturation (SpO2) were monitored. Children's cooperation levels were measured using the Venham Clinical Cooperation Scale (VCCS). Results: The VPT scores were significantly higher in the CBG group than in the N2O/O2 and hypnosis groups (p < 0.001). The VCAS scores in the N2O/O2 group were lower than those in the CBG group (p < 0.05) and were comparable to those in the hypnosis group. The VCCS scores were significantly higher in the CBG group than in the N2O/O2 and hypnosis groups (p < 0.05). HR changes in the N2O/O2 group were significantly lower than in the hypnosis and CBG groups (p < 0.05). No significant difference in pain was observed between the groups the day after the intervention. Conclusion: N2O/O2 inhalation and hypnosis are effective in reducing self-reported and observed anxiety and improving cooperation levels in pediatric patients during dental extraction. Moreover, the frequency of reported pain was lower in the hypnosis group compared to the other groups.

Evaluation of various obturation techniques with bioceramic sealers in 3D-printed C-shaped canals.

This in vitro study compared various obturation techniques with bioceramic sealers for filling C-shaped 3D-printed replicas. A mandibular molar with a C-shaped root canal with a C1 configuration was obtained. After instrumenting with M3 Pro Gold files (United Dental, Shanghai, China) up to size #30/0.04, a CBCT scan of the tooth was taken. Sixty 3D-printed replicas of the tooth were created. The samples were obturated with EndoSeal TCS sealer (E. TCS; Maruchi, Wonju, Korea) or EndoSeal MTA (E. MTA; Maruchi, Wonju, Korea) (n = 30). The samples in each group were obturated with the following techniques (n = 10): (1) single-cone technique (SC), (2) SC with ultrasonic activation (UA), and (3) cold hydraulic compaction (CHC). Following incubation, the replicas' apical, middle, and coronal thirds were inspected under a digital microscope, and the proportion of filling material and void were calculated. Also, the obturation time and sealer extrusion were recorded. Data were analyzed using ANOVA, LSD post-hoc, and the chi-square tests (α = 0.05). The results indicated that in the apical third, E. TCS-SC, E. TCS-UA, and E. MTA-UA had the lowest void percentage among groups (p < 0.05). In the middle thirds, samples obturated with E. TCS-UA showed a significantly lower void percentage among all groups (p < 0.05). However, in the coronal third, E. TCS-CHC showed the least void percentage (p < 0.05), followed by E. TCS-UA and E. MTA-CHC. The E. TCS-SC and E. TCS-UA were the least time-consuming methods (p < 0.05). Sealer extrusion significantly differed among the groups, with E. MTA-UA and E. TCS-UA showing higher incidence (p = 0.019). It was concluded that E. TCS-UA was the most convenient obturation technique. However, care must be taken when obturating the canals with high flow and ultrasonic activation near the vital anatomical landmarks.

The development of a serious game for laser applications in dentistry and the evaluation of dental students' satisfaction.

BACKGROUND: This study aimed to design and implement a gamified application about the theoretical aspects of laser applications in dentistry and investigate students' satisfaction with their learning experience. METHODS: An engaging educational program named Essential Skills and Knowledge in Learning Laser (ESKILLD) was developed to teach laser applications in dentistry. The program comprises two primary components: a "Tutorial and Quiz" section and a "Games" section. Final-year dental students were tasked with installing and using this application. A 29-item validated questionnaire (Cronbach's alpha = 0.97, ICC = 0.94) was used to evaluate students' perceptions of the applications' design and functionality. The influence of participants' gender and Grade Point Average (GPA) on their satisfaction levels was examined via the student t-test and Pearson's correlation, with a significance level of 0.05. RESULTS: The study had 56 participants, of which 37 were female (66.07%), and 19 were male (33.92%). The students' average GPA was 15.16 out of 20. The mean rating for ESKILLD's design and functionality was 1.39 ± 0.47 and 1.37 ± 0.46, respectively, signifying a high satisfaction level. Female students rated the application's coherence and learning perception significantly higher than their male counterparts (p < 0.05). However, gender did not significantly influence scores on other perception aspects or overall scores. Students' GPAs and their perception scores did not have a significant correlation. CONCLUSIONS: The results indicate that the participants were generally satisfied with the game's features and attitudes towards it, which underscores the potential effectiveness of gamification in dental courses focused on laser applications.

Investigating the efficacy of a varnish containing gallic acid on remineralization of enamel lesions: an in vitro study.

This study evaluated the efficacy of a formulated remineralizing gallic acid (GA) varnish in treating artificial enamel caries lesions. Fifty-five intact bovine incisors were collected. Enamel blocks (5 × 9 mm) were prepared. A third of each block's surface remained intact. Primary carious lesions were induced on the middle and bottom thirds of the blocks by immersing the samples in a demineralization solution for 6 h. The bottom third of the blocks were further remineralized by randomly applying 0.5%, 2%, or 8% GA varnishes and 2.26% fluoride varnish (V varnish, Vericom, Seoul, Korea), or the varnish base without active ingredients (n = 11 each). The specimens were immersed in a remineralizing solution for 4 h and then subjected to a 2-hour immersion in the demineralizing solution. After six days of pH cycling, the surface microhardness was measured at depths of 30, 75, and 120 µm. The percentage of surface microhardness recovery (SMHR%) was compared among the groups using the Shapiro-Wilk, ANOVA, and Tukey HSD post-hoc tests (α = 0.05). The SMHR% of all experimental groups was higher than the control group at 30 µm (p < 0.05). The 0.5% GA varnish showed the highest SMHR% at all depths; however, the difference with the other experimental groups was significant at a depth of 30 µm (p < 0.05). The SMHR% of the fluoride and the 2% and 8% GA varnishes was comparable at all depths. All treatments potentially remineralize enamel lesions, with 0.5% GA varnish having the greatest effect, particularly on the top surface layer. As such, this newly developed varnish may emerge as a promising alternative to fluoride varnish.

The impact of immediate versus delayed mini-screw placement on alveolar bone preservation and bone density following tooth extraction: evidence from a canine model.

The aim of this study was to evaluate the impact of mini-screw placement on the alveolar ridge using a split-mouth design. Twelve beagles underwent bilateral extraction of their lateral teeth. In the immediate group, a mini-screw was unilaterally placed approximately 3-4 mm below the alveolar crest of the extraction site on the experimental side. The delayed group received mini-screws six weeks after tooth extraction. On average, the dogs were sacrificed after 11 weeks, and the maxillary bones were excised and scanned using cone-beam computed tomography (CBCT). Histopathological examinations were conducted to assess inflammation and bone formation scores. The results showed that in the immediate group, bone height was significantly greater on the intervention side compared to the control side (p < 0.05), whereas there was no significant difference in the delayed group. In both groups, there was a significant increase in bone density around the mini-screws compared to the control sides (p < 0.05). Mini-screw insertion led to a significant enhancement of bone growth in both groups (p < 0.05), with no notable differences between the two groups. The mini-screws did not have any impact on bone inflammation or width. Overall, both immediate and delayed mini-screw placement in the extraction socket positively influenced bone dimensions, density, and histological properties. However, immediate insertion was more effective than delayed placement in preserving vertical bone height, despite delayed insertion resulting in higher bone density.

Nudging oral habits; application of behavioral economics in oral health promotion: a critical review.

Background: Oral health disorders significantly contribute to the global incidence of chronic diseases. Nudge interventions have demonstrated effectiveness in enhancing people's decision-making and self-management capacities in a cost-efficient manner. As a result, these interventions could be valuable tools for fostering improved oral care habits. This critical review explores potential behavioral nudges applicable to promoting oral health. Methods: A thorough electronic literature search was conducted on Scopus, Embase, and PubMed databases for papers published post-2008. The search focused on empirical evidence concerning the direct and indirect application of Nudge theory in oral health enhancement. In addition, the investigation included the nudge intervention's role in managing common non-communicable disease risk factors (tobacco, alcohol, and sugar) and their use in other health sectors. Results and conclusion: There is a dearth of studies on behavioral economics, particularly those involving reward and reminder techniques. However, various successful nudge interventions have been identified in other sectors that aim to improve health decisions. These include strategies encouraging healthier nutritional choices, tobacco and alcohol cessation, medication compliance, routine physical activity, and regular health check-ups. Such interventions can also have direct or indirect positive impacts on oral health. Implementing these interventions within an oral care framework could promote oral health due to similar underlying cognitive mechanisms. However, different types of nudge interventions have varying degrees of effectiveness. Furthermore, factors such as the method of delivery and the characteristics of the targeted population significantly influence the outcome of the intervention. Hence, it is imperative to conduct extensive studies in diverse socioeconomic settings to fully understand the potentials, limitations, and impacts of nudge interventions in promoting oral health.

Statins, allies against antibiotic resistance?

Due to the ever-increasing rate of antibacterial resistance, the search for effective antibacterial agents has become imperative. Researchers have investigated the potential antimicrobial properties of various classes of nonantibiotic drugs. Statins are a group of antihyperlipidemic drugs with several cholesterol-independent effects, including anti-inflammatory, immune-modulating, antioxidant, and antibacterial effects. In vitro and in vivo studies have demonstrated the antibacterial properties of statins against various gram-positive and gram-negative bacteria. Simvastatin and atorvastatin are the most potent members of the family. Their antibacterial effect can be attributed to several direct and indirect mechanisms. Bacterial invasion, growth, and virulence are affected by statins. However, since in vitro minimum inhibitory concentrations (MICs) are significantly higher than serum concentrations at the lipid-lowering dosage, indirect mechanisms have been suggested to explain the positive clinical results, including reducing inflammation and improving immune response capacity. Further, statins have shown promising results when combined with antibiotics and other antibacterial agents, such as triazenes and silver nanoparticles. Despite this, the controversial aspects of statins have cast doubt on their efficacy as a possible solution for antibacterial resistance, and further research is required. Consequently, this review will examine in detail the current clinical and in vitro findings and controversies regarding statins' antibacterial properties and their relevance to antibacterial resistance.

Dentists' lived experience of providing dental care during the COVID-19 pandemic: A qualitative study in Mashhad, Iran.

Background: This study aimed to explore the lived experiences of dentists practicing in Mashhad, Iran, during the COVID-19 pandemic and identify possible influencing factors for providing dental health in this era. Methods: Sixteen dentists took part in this qualitative phenomenological study. Semi-structured face-to-face interviews were performed and evaluated using a qualitative content analysis approach. The MAXQDA program (2020) was used to code and classify the data. Purposive sampling, audio recording, member checking, and peer review were employed to verify transferability, reliability, and validity. The interview transcripts were transcribed, and sentences and remarks relevant to the study's goal were retrieved and classified. Results: Six hundred twenty-eight codes were extracted after several readings of the texts. Five core themes and fourteen sub-themes were determined after deleting repeated themes and axial coding. The main five themes included: "Coping with the COVID-19 pandemic", "Alternations in providing dental care," "Infection control," "COVID-19-related news and information sources", and "Positive and negative aspects of COVID-19 in dental care ". Conclusions: During the COVID-19 pandemic, dentists noted various challenges in delivering routine dental treatment, including a lack of resources, reliable and straightforward guidelines for dentists, and governmental policies for dental facility restrictions. Dentists concluded that financial, educational, and financial support from the government would significantly enhance the delivery of community dental care services. With the right strategies and lessons learned, dentists may be better prepared for future challenges in global health care.

CRISPR-Cas system as a promising player against bacterial infection and antibiotic resistance.

The phenomenon of antibiotic resistance (AR) and its increasing global trends and destructive waves concerns patients and the healthcare system. In order to combat AR, it is necessary to explore new strategies when the current antibiotics fail to be effective. Thus, knowing the resistance mechanisms and appropriate diagnosis of bacterial infections may help enhance the sensitivity and specificity of novel strategies. On the other hand, resistance to antimicrobial compounds can spread from resistant populations to susceptible ones. Antimicrobial resistance genes (ARGs) significantly disseminate AR via horizontal and vertical gene transfer. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system is a member of the bacterial immune system with the ability to remove the ARGs; therefore, it can be introduced as an effective and innovative strategy in the battle against AR. Here, we reviewed CRISPR-based bacterial diagnosis technologies. Moreover, the strategies to battle AR based on targeting bacterial chromosomes and resistance plasmids using the CRISPR-Cas system have been explained. Besides, we have presented the limitations of CRISPR delivery and potential solutions to help improve the future development of CRISPR-based platforms.