Association of Body Mass Index and Chronology of Tooth Eruption in Children visiting a Dental Hospital in UAE: A Cross-sectional Study.

The objective of this research was to investigate the relationship between body mass index (BMI) and the mean age at which permanent teeth erupt in school-going children. Materials and Method: This cross-sectional study at RAK College of Dental Sciences, UAE, involved 89 children aged 6-14 years. Erupted teeth in the mouth were included. Statistical analysis, including t-tests, ANOVA, and Kruskal-Wallis, was conducted using SPSS version 29, with a significance threshold set at p < 0.05. Results: Out of 89 children (41 girls and 48 boys) in the study, 56.17 % had normal weight, 20.22 % were overweight, 17.97 % were underweight, and 5.6 % were obese. Female children generally experienced earlier permanent tooth eruption than males. Additionally, there was an observed trend of earlier tooth eruption with increasing weight or BMI. Underweight children notably displayed a delayed mean age of tooth eruption. Conclusion: This study demonstrates a notable correlation between BMI and the mean age at which permanent teeth erupt in school-going children aged 6 to 14 years who visited our dental hospital. To establish a more precise understanding of the connection between BMI and dental development, we recommend conducting further longitudinal studies involving multiple centers. Clinical Significance: Monitoring a child's BMI is crucial for assessing dental health and planning tailored treatment for those aged 6 to 14. Understanding the BMI's connection to permanent tooth eruption timing allows dental professionals to identify trends in early or delayed development. This enables them to customize treatment strategies, promoting a precise and personalized approach for better oral health outcomes in this age group.

Impact of Bone Morphogenetic Protein 7 and Prostaglandin receptors on osteoblast healing and organization of collagen.

PURPOSE: This study seeks to investigate the impact of co-administering either a Prostaglandin EP2 receptor agonist or an EP1 receptor antagonist alone with a low dose BMP7 on in vitro healing process, collagen content and maturation of human osteoblasts. METHODOLOGY: Human osteoblast cells were used in this study. These cells were cultured and subjected to different concentrations of Prostaglandin EP2 receptor agonist, EP1 receptor antagonist, BMP7, Control (Ct) (Vehicle alone), and various combinations treatments. Cell viability at 24, 48 and 72 hours (h) was evaluated using the XTT assay. A wound healing assay was conducted to observe the migration ability of human osteoblast cells. Additionally, Sirius red staining and Fourier-Transform Infrared Spectroscopy Imaging (FT-IR) was employed to analyze various parameters, including total protein concentration, collagen production, mature collagen concentration, and mineral content. RESULTS: The combination of low dose BMP7 and Prostaglandin EP2 receptor agonist resulted to the lowest cell viability when compared to both the Ct and individual treatments. In contrast, the Prostaglandin EP1 receptor antagonist alone showed the highest cellular viability at 72 h. In the wound healing assay, the combined treatment of low dose BMP7 with the Prostaglandin EP2 receptor agonist and EP1 receptor antagonist showed a decrease in human osteoblast healing after 24 h. Analysis of FT-IR data indicated a reduction in total protein content, collagen maturity, collagen concentration and mineral content in combination treatment compared to the single or Ct treatments. CONCLUSION: The combination of a Prostaglandin EP2 receptor agonist or an EP1 receptor antagonist when combined with low dose BMP7 significantly hinders both human osteoblast healing and collagen maturity/concentration in comparison to low dose BMP7 treatment alone.

Understanding patient safety in dentistry: evaluating the present and envisioning the future-a narrative review.

BACKGROUND: Patient safety is crucial in dentistry, yet it has received delayed recognition compared with other healthcare fields. This literature review assesses the current state of patient safety in dentistry, investigates the reasons for the delay, and offers recommendations for enhancing patient safety in dental practices, dental schools, and hospitals. METHODS: The review incorporates a thorough analysis of existing literature on patient safety in dentistry. Various sources, including research articles, guidelines and reports, were reviewed to gather insights into patient safety definitions, challenges and best practices specific to dentistry. RESULTS: The review underscores the importance of prioritising patient safety in dentistry at all levels of healthcare. It identifies key definitions and factors contributing to the delayed focus on patient safety in the field. Additionally, it emphasises the significance of establishing a patient safety culture and discusses approaches such as safety plans, incident management systems, blame-free cultures and ethical frameworks to enhance patient safety. CONCLUSION: Patient safety is vital in dentistry to ensure high-quality care and patient well-being. The review emphasises the importance of prioritising patient safety in dental practices, dental schools and hospitals. Through the implementation of recommended strategies and best practices, dental organisations can cultivate a patient safety culture, enhance communication, mitigate risks and continually improve patient safety outcomes. The dissemination of knowledge and the active involvement of all stakeholders are crucial for promoting patient safety and establishing a safe dental healthcare system.

Potential Role of BMP7 in Regenerative Dentistry.

In recent years, the field of regenerative dentistry has garnered considerable attention for its focus on restoring and renewing damaged dental tissue. This narrative review explores the potential of bone morphogenetic protein 7 (BMP7) and its diverse applications in the regeneration of dental tissue. Recently, significant efforts have been made to understand BMP7's role in advancing regenerative dentistry. Amongst the various signalling molecules investigated for their regenerative capabilities, BMP7 emerges as a pivotal candidate, demonstrating the ability to stimulate the regeneration of dental pulp, periodontal, craniofacial, and alveolar bone tissues for dental implant placement. Whilst BMP7 exhibits significant promise as a therapeutic agent in regenerative dentistry, further research and clinical trials are necessary to fully unlock its potential and optimise its clinical effectiveness in addressing diverse dental and craniofacial conditions. This review highlights BMP7's substantial potential and emphasises the ongoing need for continued research to effectively harness its clinical utility in diverse dental and craniofacial contexts.

Computer aided design/computer aided manufacturing (CAD/CAM) technology in the undergraduate dental programs in the MENA region.

INTRODUCTION: The aim of this study was to understand the trends of teaching Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) in the undergraduate dental curriculum in the MENA region by conducting an online survey among the undergraduate dental colleges in this region. MATERIALS AND METHODS: An online survey was conducted using Google Forms consisting of 20 questions that could be answered by "yes" or "no" responses, multiple-choice answers or in a descriptive, "open" format. A total of 55 participants from the MENA region representing their dental college were requested to participate in this study. RESULTS: The response rate of the survey was 85.5% following the twofold follow-up reminders method. Although the vast majority of professors demonstrated vital knowledge in the practical use of CAD/CAM, the majority of them did not provide theoretical and practical training on CAD/CAM in their institutions. Among the schools with established levels of teaching CAD/CAM, nearly 50% of them provide both pre-clinical and clinical training on CAD/CAM. Despite the availability of extra-curricular training courses on CAD/CAM outside the university setting, there is a lack of advocating for students to enrol in those courses by the institutions. More than 80% of the participants agreed that CAD/CAM has a strong future in chair-side dental clinics and CAD/CAM needs to be incorporated within undergraduate studies. CONCLUSION: Based on the results of the current study, it is understandable that an intervention is required by the dental education providers to cope with the growing demand for CAD/CAM technology for the current and future dental practitioners of the MENA region.

Phytic acid effect on periodontal ligament fibroblast: An in-vitro study.

OBJECTIVES: This study evaluated phytic acid (IP6) effect on the viability, alkaline phosphatase (ALP) activity and calcium release of human periodontal ligament (HPDL) cells in optimal (OGL) and elevated glucose level (EGL) in cell culture media. MATERIALS AND METHODS: Cells were seeded in OGL (1000mg/L) or EGL (4500 mg/L) media. IP6 was added at 0.005%, 0.01% or 0.02% concentrations for 24 or 48h, and XTT assay was performed. Cell differentiation and calcium release in presence of 0.02% IP6 in OGL or EGL in non-osteogenic or osteogenic media were analyzed using ALP assay and alizarin red staining, respectively. RESULTS: In OGL, IP6 enhanced the viability of the cells at both exposure times (P<0.05). However, IP6 lowered the viability of the cells with the presence of EGL compared to the control at both exposure times, except for 0.02% IP6 which showed comparable viability to the control at 48 h. In OGL and EGL, ALP activity of the cells was not affected by the presence of IP6 in non-osteogenic media; however, in osteogenic media IP6 lowered the ALP activity. Meanwhile, calcium release was the highest with IP6 within osteogenic media of EGL. CONCLUSIONS: IP6 effects on the HPDL cells were dependent on IP6 concentration, time of exposure, glucose levels and the osteogenic condition of the media. CLINICAL RELEVANCE: This study gives insights on the potential therapeutic effect of IP6 as adjunctive periodontal therapy in patients with diabetes.

Inhibition of Silver Diamine Fluoride-induced Tooth Discoloration by Using Natural Antioxidant: In Vitro Study.

AIM: Silver diamine fluoride (SDF) is a well-known caries preventive aid capable of arresting carious lesions and preventing secondary caries formation. Despite having the caries prevention potential, the clinical use of SDF is limited due to the tooth discoloration caused by SDF. The objective of this study was to evaluate the efficiency of natural antioxidants to inhibit SDF-induced tooth discoloration. MATERIALS AND METHODS: A total of 32 bovine teeth were polished to create a 6 mm circular window on the middle 1/3 (for enamel) or on the cervical 1/3 (for dentin) of the labial surface. Specimens were treated either with SDF alone or SDF followed by ascorbic acid (AA)/alpha lipoic acid (ALA)/7th generation bonding materials. The color parameters Lightness (L*), Chroma (C*), and Hue (H*) of the tooth window were measured at pretreatment, 1-hour, 1-week, and 1-month posttreatment using a digital color chromometer. RESULTS: Repeated measure ANOVA showed a significant tooth color alteration at 1-hour posttreatment. The L* and H* values dropped and C* value elevated significantly in 1-hour posttreatment measurement. All experimental groups showed significant tooth color alteration after treatment (p < 0.05) and were unable to reverse the discoloration even after 1-month period except the ALA group which did not show any significant (p > 0.05) color alteration compared with the pretreatment value. CONCLUSIONS: Within the limitation of the in vitro model and according to the results of this study, it can be concluded that ALA has the potential to prevent SDF-induced tooth discoloration; however, AA was unable to prevent the discoloration. CLINICAL SIGNIFICANCE: SDF induces discoloration of enamel and dentin can be reversed by applying Alpha lipoic acid immediacy after SDF application.

Tracing of Microbes in Prepared Cavity Following Different Minimally Invasive Caries Removal Protocols.

AIMS: The conventional caries removal technique has been replaced with minimally invasive (MI) techniques to preserve healthy natural teeth and to provide durable dental restorations. Each of these MI caries removal protocols is reported to be favorable in dealing with different caries conditions. The current study aimed to trace the residual bacteria that may remain in a prepared cavity following a visual-tactile (VT), caries detection dye (CDD), and chemo-mechanical caries removal (CMCR) protocol. MATERIALS AND METHODS: A total of 29 extracted human molar teeth with visible caries lesions were randomly divided into three groups. The cavity preparation and caries removal of each group was accomplished following one of the MI caries removal protocols. Swab samples (one from each specimen) were taken and inoculated onto a blood agar plate and incubated for 48 hours. The growth of the bacterial colony was observed under a microscope and the specific genome of the bacteria was identified by polymerase chain reaction (PCR) test. RESULTS: The maximum number of traceable bacteria was observed following the chemo-mechanical caries removal group followed by the caries detection dye group and the least in the visual-tactile group. The PCR test revealed the presence of Streptococcus mutans in all the observed colonies; however, Streptococcus sobrinus was absent completely. The Chi-square test reveals a statistically insignificant (p = 0.646) difference among the tested groups. CONCLUSION: All of the MI caries removal protocols used in this study showed a trace of microbes in certain teeth. The cavity prepared following a visual tactile protocol showed the least amount of traceable bacteria in the prepared cavity. CLINICAL SIGNIFICANCE: Cavity that is prepared following individual MI protocol has a risk of leaving microbes in it.

Association between Salivary Cortisol Levels, Dental Anxiety, and Dental Caries in Children: A Cross-Sectional Study.

AIM: This study aimed to investigate the relationship between dental caries, dental anxiety, and salivary cortisol levels in children visiting pediatric dental clinics and their implications on pediatric oral health. MATERIALS AND METHODS: A cross-sectional study was conducted at a dental university in the UAE. A total of 60 children, aged 4-12 years, were included. Salivary cortisol levels were measured using an Enzyme-Linked Immunosorbent Assay (ELISA) kit. Dental caries status was evaluated, and dental anxiety levels were assessed using the Modified Dental Anxiety Scale (MDAS). Statistical analyses, including Mann-Whitney U test and Pearson's correlation coefficient, were performed to determine significant differences and associations. RESULTS: The study group showed significantly higher salivary cortisol levels compared to the control group (p < 0.0001). A strong positive correlation was found between salivary cortisol levels and dental caries status (p < 0.001). However, no significant difference in dental anxiety levels was observed between the study and control groups (p = 0.85). A strong positive correlation was found between dental anxiety levels and dental caries status (p < 0.001). CONCLUSION: The findings indicate a significant association between salivary cortisol levels and dental caries, suggesting that higher cortisol levels are associated with active caries. Dental anxiety levels were positively correlated with dental caries. Understanding the relationship between these variables can contribute to better oral health strategies and interventions for children, emphasizing the importance of managing dental anxiety and stress in pediatric dental care. CLINICAL SIGNIFICANCE: This study highlights the potential of salivary cortisol as a biomarker for assessing stress and its impact on oral health in children. By addressing dental anxiety and stress, dental professionals can provide child-friendly dental care, enhance preventive measures, and improve oral health outcomes in pediatric patients.

In Vitro Optical and Physical Stability of Resin Composite Materials with Different Filler Characteristics.

The objective of this study was to compare the physical and optical stability of resin composite materials with different filler characteristics. Ninety-six resin composite blocks (6 mm × 6 mm × 2 mm) were prepared using four different types of resin composite, divided into four groups. Specimens from the same material were randomly divided into four groups (n = 6) and allocated for Vickers hardness (VH), water sorption, solubility (WS/SL), and staining and aging challenges tests. One-way ANOVA showed significant differences in microhardness (p = 0.0001), WS (p = 0.0001), and SL (p = 0.003) among the tested groups. Beautifil II LS recorded the highest hardness, and CharmFil®Flow had the lowest value. Beautifil Injectable X and II LS showed negative WS, whereas the other groups had positive values. All groups showed positive SL. Repeated measures ANOVA showed significant color parameter alteration in the tested groups (p = 0.0001). All groups showed significant color shifting after one week of the staining challenge. Repeated measures ANOVA showed a significant color parameter (p = 0.0001) and weight (p = 0.001) alteration after the aging challenge. The optical and physical stability of resin composites may vary according to filler characteristics. Clinicians should choose the composite as per the desired outcome.

Effect of different chelating agents on the shear bond strength of calcium silicate-based cements to coronal dentin.

We evaluated the shear bond strength (SBS) of mineral trioxide aggregate (MTA) and Biodentine (BD) to coronal dentin after treatment with ethylenediaminetetraacetic acid (EDTA), phytic acid (IP6), or etidronic acid (HEDP). Sodium hypochlorite-treated dentin surfaces were randomly divided into four groups according to conditioning protocol namely, 17% EDTA, 2.5% IP6, 9% HEDP, or distilled water (DS). Specimens were further divided according to the type of cement placed on conditioned dentin and SBS was tested. The results showed that DS/MTA and IP6/MTA groups had the highest values, and there was no significant difference between these two groups. IP6/BD group showed a lower SBS value compared to IP6/MTA; however, this did not reach the level of significance. The BS to dentin was influenced by the type of calcium silicate material and chelating agent. IP6 either improved or maintained the bonding while EDTA and HEDP showed a negative or no influence effect.

Tinnitus Prevalence and Associated Factors among Dental Clinicians in the United Arab Emirates.

Dental clinicians are at increased risk for developing tinnitus due to exposure to high levels of occupational noise. This study aimed to determine tinnitus prevalence and associated factors among dental clinicians. Interviews were conducted with 150 randomly selected dental clinicians using a questionnaire. Noise levels were measured at three points of time at the operating area. Tinnitus was reported in 19.33% of the participants. The average noise level was significantly higher among participants with tinnitus compared to those without the condition. More participants complained of intermittent tinnitus and the rest had the constant type, with the latter being significantly more bothersome. The weekly average time of using high-speed handpieces, suction and electric handpieces, age and experience had a significant effect on the presence of tinnitus. Only 2.7% of the participants reported the use of a hearing protection device. Tinnitus is a common finding among dental clinicians especially those with higher levels of occupational noise and more frequent use of noise-generating equipment. Knowledge of tinnitus prevalence aids in realizing the extent of its impact and making informed decisions. These results call for improved awareness of the negative impact of clinically-generated noise and emphasize the importance of preventive measures and periodic audiometry exams.

The Blending Effect of Single-Shade Composite with Different Shades of Conventional Resin Composites-An In Vitro Study.

OBJECTIVES: Single-shade composite systems are gaining popularity among clinicians due to the claimed potential of blending with different tooth structure shades while restoring the tooth. The purpose of this study was to evaluate the blending effect of two single-shade composite with different shades of conventional resin composite systems. MATERIALS AND METHODS: Seventy-two composite cylinders of B1, B2, A1, A2, A3, or A3.5 shade from CharmFil Plus (CP) and Filtek Universal Restorative (3M) were prepared using custom-made silicone mold. Single-shade composite OMNICHROMA (OC) or Beautifil II Enamel (BE) was placed in the center of each cylinder and polymerized. The color parameters, lightness (L*), chroma (C*), and hue (H*) of each composite were measured using a color chronometer. Furthermore, color stability of the samples was evaluated after 1-week staining challenge. STATISTICAL ANALYSIS: Multivariant analysis was performed to evaluate the effect of material and shade on the color parameters. Multiple comparisons of the data were performed using post hoc test. The staining challenge data were analyzed using repeated measure analysis of variance and paired sample T-test. RESULTS: The multivariant analysis showed a statistically significant difference in color parameters among CP, 3M, OC, and BE (p = 0.001). Image analysis showed a visual blending effect for both OC and BE for certain shades; however, some color contrast with the darker shades was observed. The C* value of OC showed a similar pattern to CP; however, the H* of the latter was closely followed by BE. The L* value showed statistically significant difference among the shades of 3M, and in OC and BE when blended with 3M. CONCLUSION: All four materials used in this study showed color alteration after the staining challenge. Single-shade composite can blend with only certain shades of resin composites.

Endodontic Procedural Errors and Associated Factors among Undergraduate Dental Students: A Cross-sectional Study.

AIMS AND BACKGROUND: To assess the procedural errors committed by undergraduate students at RAK College of Dental Sciences, during root canal treatments and the factors associated with these errors. MATERIALS AND METHODS: In this cross-sectional study, 180 self-administered questionnaires were distributed, each comprising 26 questions, among 4th and 5th-year students. Participants were requested to report their endodontic mishaps based on feedback from their supervisors. The questionnaire assessed the frequency and types of procedural errors, considering patient, operator, and tooth-related factors. Data were collected tabulated and analyzed using the Chi-square test. RESULTS: A total of 124 root canal-treated teeth exhibiting iatrogenic errors done by students were assessed. Out of which, 53% were performed by 5th-year students, and 69% were conducted by female operators. About 62% of errors occurred in the upper teeth and 68% in the posterior teeth. The most prevalent errors during the rubber dam isolation step were soft tissue trauma (21%) and isolation leakage (20%), significantly associated with limited mouth opening, excessive salivation, and tooth malalignment (p < 0.05). Apical blockage (15%) emerged as the most frequent error during instrumentation phase, showing a significant association with canal dimension and curvature (p < 0.05). For access cavity and obturation phases, under-extended cavity (9%), and under-extended filling (11%) were the most reported errors, respectively. CONCLUSION: Tooth isolation emerges as a particularly challenging aspect for dental students, particularly when dealing with patients exhibiting limited mouth opening and excessive salivation. CLINICAL SIGNIFICANCE: Clinical instructors should caution the undergraduates about the heightened risk of endodontic procedural errors when dealing with patients exhibiting limited mouth opening, excessive salivation, tooth misalignment, and narrow canals. Addressing these challenges is crucial for enhancing the proficiency of undergraduate students in performing successful root canal treatments. How to cite this article: Elsayed MA, Islam MS, Saleh DR, et al. Endodontic Procedural Errors and Associated Factors among Undergraduate Dental Students: A Cross-sectional Study. J Contemp Dent Pract 2023;24(12):998-1007.

The Impact of Social Media on Professional Learning among Undergraduate Dental Students: A Cross-sectional Study.

AIM: To explore the advantages and drawbacks of social media (SM) use in undergraduate dental students' education. MATERIALS AND METHODS: This cross-sectional study was conducted among 202 undergraduate students at RAK College of Dental Sciences. A questionnaire of 15 questions explored demographic information, the nature of SM used by the participants, the use of SM for educational purposes, and the negative impacts of SM use. Frequencies, percentages, and significant variables were analyzed using Chi-square test at a 95% confidence level (CI) using statistical software [Statistical Package for the Social Sciences (SPSS), version 26.0]. RESULTS: Among the participants, 95% were SM users, and 80% had been using it for more than 5 years. 95% use SM regularly, and 70% spend 2-6 hours daily using SM. The primary purpose of using SM was entertainment and communication, mostly Instagram (82.38%), followed by Snapchat (58.49%) and YouTube (47.15%). Furthermore, SM is effective in obtaining new information (85%), and 90% consider clinical procedures on YouTube to be a helpful learning tool. Moreover, 75% of the participants recommended using SM as a learning tool, and 85% of the participants considered SM tutorial videos to be evidence-based. However, 70% of users are concerned about their addiction to using SM during lecture, laboratory, clinic, and examination periods, and 37% of them think spending time on SM can negatively affect their academic performance. CONCLUSION: Undergraduate dental students frequently use SM for entertainment, communication, and educational purposes. Nevertheless, the addiction to SM negatively affects the students learning progress. CLINICAL SIGNIFICANCE: The use of SM has both a positive and negative impact on undergraduate dental education. Incorporating evidence-based learning components into SM platforms can be useful in dental education. How to cite this article: Farghal NS, Islam MS, Dasnadi SP, et al. The Impact of Social Media on Professional Learning among Undergraduate Dental Students: A Cross-sectional Study. J Contemp Dent Pract 2023;24(11):877-886.

The effect of different finishing polishing protocols on stain absorption and color stability of resin composite restorations.

PURPOSE: To evaluate the degree of stain absorption of resin composite following different finishing and polishing protocols and to evaluate the efficacy of prophylaxis paste with or without addition of carbamide peroxide to remove composite surface stain. METHODS: 50 resin composite blocks were prepared using nano-hybrid composite (Filtek Z250XT) and giomer (Beautifil II LS). Specimens were either polished with a disk or coated with 5th/7th generation bonding or glycerin gel. The color parameters (lightness, chroma and hue) of the specimens were measured prior to staining, and after 1 and 2 weeks of staining using a color chromometer. The composite surface stain removal capability of prophylaxis pastes with or without the addition of carbamide peroxide was evaluated before and after polishing. RESULTS: The repeated measures ANOVA showed that composite polished with a polishing disk or coated with glycerin gel have better color stability compared to composite without any polishing or coated with 5th or 7th generation bonding materials. The prophylaxis paste was able to remove composite surface stain; however, the addition of carbamide peroxide did not show any additional benefit. The results suggested that polishing with polishing disks or coating with glycerin gel is useful for the color stability of resin composite. CLINICAL SIGNIFICANCE: Selection of finishing and polishing protocols varies among individual practitioners. Each of these protocols has some pros and cons concerning the esthetic and color stability of composite. The present results suggested that the use of polishing disk or glycerin gel during polymerization would be a useful protocol to achieve and maintain esthetically stable composite restorations.

Trace metals and organochlorine pesticide residues in imported fishes in Bangladesh and human health risk implications.

Substantial quantity of fish has been imported to Bangladesh without adequate food safety assessment which can pose a serious health risk to local people. This study analyzed the trace metals and organochlorine pesticides residues and the associated human health risk in 33 imported fishes (9 species) from four countries (India, Myanmar, Oman, and United Arab Emirates) collected from three different ports (Benapole, Bhomra, and Chittagong) of Bangladesh with invoice lists from the port authorities. Trace metal concentrations were determined using graphite furnace absorption spectrometry and flame absorption spectrometry. The two organochlorine pesticides (Aldrin and Chlordane) residues were determined by GC-MS and found as below detection level (BDL). The trace metal concentrations (mg/kg-ww) in imported fish samples ranged as As 0.008 to 0.558, Pb 0.004 to 0.070, Cr 0.010 to 0.109, Cd 0.00 to 0.083, Ni 0.011 to 0.059, Co BDL to 0.067, Mn BDL to 0.0780, Fe 1.780 to 10.77, Cu 0.055 to 0.632, and Zn 0.898 to 9.245. Concentrations of As and Cd were higher than the food safety guideline. Considering the source country of imported fishes, fish samples from Oman were mostly contaminated by the trace metals. The estimated daily intake (EDI) was higher for Cr. However, the target hazard quotient (THQ) for individual metal and total THQ for combined metals were lower than 1, indicating no apparent non-carcinogenic health risk for consumers. The cancer risk (CR) was within the acceptable range. But extensive monitoring of these toxic chemicals is needed prior to import these fishes to the country. Given the self-sufficiency in fish production, this study also argues whether Bangladesh needs to import the fishes at all.

Teaching of the repair of defective composite restorations in Middle Eastern and North African Dental Schools.

OBJECTIVES: To evaluate the status of teaching of repair of defective resin-based composite restorations in dental schools in the Middle Eastern and North African (MENA) countries. METHODS: A validated 14-item questionnaire was mailed to the directors of the operative/restorative dentistry department in 40 MENA dental schools. Data were collected on teaching, including whether the repair of resin-based composite restorations was part of the dental school curriculum; the rationale behind the teaching; how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability and expected longevity of the repair procedure. RESULTS: Thirty-two schools responded to the survey (response rate of 80%). Twenty-two (69%) schools reported the teaching of resin-based composite repairs as an alternative to the replacement of restorations. Of the schools not teaching repairs, 80% indicated that they plan to include this topic in the curriculum within the next five years. Most schools taught theoretical and practical aspects of repair at a clinical level only. Two-thirds of schools reported tooth substance preservation being the main reason for teaching repair techniques. The main indications for repair treatment were marginal defects (59%), followed by partial loss of restoration (56%). Most schools that performed repairs reported high patient acceptability. Considerable variation was noted in relation to expected longevity of resin- based composite repairs. CONCLUSIONS: The repair of defective resin-based composite restorations is actively taught within most of the surveyed schools. Advantages of repair, compared to replacement include minimum intervention, preservation of tooth structure, and savings of time and cost. CLINICAL SIGNIFICANCE: The decision between replacing or repairing a defective resin-based composite restoration in the MENA region tends to be based on clinicians' subjective experience and judgement. However, to further enhance the teaching of resin-based composite repair standardised guidelines need to be developed based on existing evidence.

Effect of phytic acid as an endodontic chelator on resin adhesion to sodium hypochlorite-treated dentin.

OBJECTIVES: Phytic acid (IP6), a naturally occurring agent, has been previously reported as a potential alternative to ethylenediaminetetraacetic acid (EDTA). However, its effect on adhesion to sodium hypochlorite (NaOCl)-treated dentin and its interactions with NaOCl have not been previously reported. Thus, in this study, the effects of IP6 on resin adhesion to NaOCl-treated dentin and the failure mode were investigated and the interactions between the used agents were analyzed. MATERIALS AND METHODS: Micro-tensile bond strength (µTBS) testing was performed until failure on dentin treated with either distilled water (control), 5% NaOCl, or 5% NaOCl followed with chelators: 17% EDTA for 1 minute or 1% IP6 for 30 seconds or 1 minute. The failed specimens were assessed under a scanning electron microscope. The reaction of NaOCl with EDTA or IP6 was analyzed in terms of temperature, pH, effervescence, and chlorine odor, and the effects of the resulting mixtures on the color of a stained paper were recorded. RESULTS: The µTBS values of the control and NaOCl with chelator groups were not significantly different, but were all significantly higher than that of the group treated with NaOCl only. In the failure analysis, a distinctive feature was the presence of resin tags in samples conditioned with IP6 after treatment with NaOCl. The reaction of 1% IP6 with 5% NaOCl was less aggressive than the reaction of the latter with 17% EDTA. CONCLUSIONS: IP6 reversed the adverse effects of NaOCl on resin-dentin adhesion without the chlorine-depleting effect of EDTA.

Investigation of the effect of a time delay on the characteristics and survival of dental pulp stem cells from extracted teeth.

OBJECTIVES: This study investigates the post-extraction storage period of human dental pulp stem cells (hDPSCs) for stem cell banking by investigating the viability, function, mineralization, and gene expression of hDPSCs isolated from extracted teeth after 1 h, 6 h and 24 h post-tooth extraction. DESIGN: hDPSCs were extracted from the pulp of impacted third molar teeth after 1 h, 6 h, and 24 h after extraction. The mesenchymal stem cell (MSCs) properties of three groups of cells were analyzed using flow cytometry. Cell morphology and proliferation were analyzed using a light microscope and an MTT assay. The viability, function, mineralization, and gene expression of hDPSCs of 1 h, 6 h, and 24 h groups were also assessed. RESULTS: The delayed harvesting of hDPSCs for 1, 6 or 24 h caused a 31 % reduction in mineral nodule formation and a reduction in the gene expression of osteocalcin (OCN) and vascular endothelial growth factor-alpha (VEGFA). However, the 1, 6 or 24 h, time delay had little effect on MTT cell proliferation, cell viability or morphology. The delayed of harvesting of hDPSCs for 1, 6 or 24 h also had little effect on the expression of MSCs positive (CD44, CD106, CD90) or negative surface markers (CD45 and CD11b). CONCLUSIONS: Our results suggest that a 24 h delay in harvesting hDPSCs from extracted teeth can reduce their mineralization and gene activity but does not markedly reduce survival. Quicker hDPSCs harvesting is likely to yield more useful hDPSCs for experimentation and clinical treatment.