Effect of silver diamine fluoride/potassium iodide treatment on the prevention of dental erosion in primary teeth: an in vitro study.

INTRODUCTION: Dental erosion has a great effect on oral health, when diagnosed it is irreversible, this sets the importance of different preventive measures being investigated against dental erosion. AIM: This in vitro study aims to evaluate the effectiveness of silver diamine fluoride and Potassium iodide (SDF-KI) in comparison to casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) varnish, sodium fluoride (NaF) varnish, silver diamine fluoride (SDF) alone and deionized water as a control group in the prevention of dental erosion in primary teeth and assessing its staining effect. MATERIALS AND METHODS: Forty deciduous teeth enamel specimens were randomly allocated into the five study groups. Tested materials were applied. An erosive challenge was done by immersing the specimens in a citric acid-containing soft drink with pH 2.85, for 5 min, 4 times/day, for 5 days. Changes in surface microhardness, mineral loss, and color change were evaluated besides recording of the surface topography and surface roughness for selected specimens. RESULTS: The highest decrease in surface microhardness was recorded in the control group (-85.21 ± 10.60%), with a statistically significant difference (p = 0.002). SDF-KI group (-61.49 ± 21.08%) showed no statistically significant difference when compared to CPP-ACPF, NaF, and SDF groups. For calcium and phosphorous loss, control group was statistically significantly higher compared to the treatment groups (p = 0.003) and (p < 0.001) respectively, while there was no statistically significant difference between the tested treatment groups. The highest mean value for color change was recorded in SDF group (26.26 ± 10.31), followed by SDF-KI group (21.22 ± 12.87) with no statistically significant difference between groups. CONCLUSIONS: SDF-KI is as effective as CPP-ACPF, NaF varnishes and SDF in the prevention of dental erosion in primary teeth, there was no statistically significant difference regarding its staining potential.

Fracture resistance of prefabricated versus custom-made zirconia crowns after thermo-mechanical aging: an in-vitro study.

BACKGROUND: Prefabricated zirconia crowns for a young permanent molar is a child-friendly solution for restoring a permanent molar at a young age. This in-vitro study aimed to compare the fracture resistance of prefabricated versus custom-made permanent molar crowns. METHODS: 16 identical resin dies were fabricated to receive permanent molar zirconia crowns, dies were divided into 2 groups, 1) received perfricated crowns, 2) custom-made crowns. Thermo-dynamic cycling was performed to simulate 6 months in the oral cavity, Fracture resistance of each group was assessed by applying increasing load till fracture. Data were tested for normality using Shapiro-Wilk and Levene's tests. Data were analyzed using independent t test. RESULTS: No statistically significant difference was found between fracture resistance of prefabricated and custom-made crowns (1793.54 ± 423.82) and (1987.38 ± 414.88) respectively. 3 crowns of the custom-made group fractured with the underlying die, versus zero dies fractured in the prefabricated group. CONCLUSIONS: Prefabricated permanent molars zirconia crowns can perform as well as custom-made crowns for an adult in terms of fracture resistance, it is suitable for children and can withstand the occlusal forces of an adult.

Influence of different personal protective equipment on children's anxiety in dental office: a randomized controlled trial.

BACKGROUND: A change in how a dentist looks may affect the child's anxiety in the dental office. This study compared the effect of conventional facial PPE versus extra PPE as reusable respirators; on the preoperative child's anxiety in the dental office. METHODS: Fifty two children were randomly allocated into 4 groups, (1) goggles + surgical mask, and (2) face shield + surgical mask versus (3) half-face respirator and (4) full-face respirator. Each child was communicated with and clinically examined by a dentist wearing the assigned PPE, and then his anxiety was assessed using CFSS-DS. Shapiro-Wilk's test was used to analyse normality. Kruskal-Wallis test followed by Dunn's post hoc test with Bonferroni correction test, were used to analyse non-parametric anxiety score data. Correlations between different factors and anxiety scores were analysed using Spearman's rank-order correlation coefficient. RESULTS: There were no statistically significant differences in the number of anxious children in each group, boys had significantly higher scores than girls (p < 0.001) For the "Goggles and surgical mask" group and "overall". There was no significant correlation between age and anxiety scores. Children who didn't have a previous dental visit had statistically significant higher scores than children with previous experience for "Goggles and surgical mask", "Face shield and surgical mask "groups and "overall". CONCLUSIONS: Half-face and full-face respirators have not affected the child's preoperative anxiety in the dental office when compared to the conventionally used PPE. Overall, there is an association between gender and previous dental visits, and dental anxiety, however; there is no correlation between child's age and dental anxiety. Dentists dealing with children should feel free to use reusable respirators, without the risk of affecting children's anxiety in the dental office. Trial Registration This study was registered on www. CLINICALTRIALS: gov , ID: NCT05371561 on 12/05/2022.

Hybrid versus distance learning environment for a paediatric dentistry course and its influence on students' satisfaction: a cross-sectional study.

BACKGROUND: During the novel COVID-19 pandemic, many universities adopted distance and hybrid learning as a modification to their teaching methods to ensure continuity of education, abiding by the worldwide recommendations of social distancing. AIM: To compare learning environments created through hybrid learning versus distance learning, to deliver paediatric dentistry course, and to assess the correlation between the created learning environment and students' satisfaction. METHOD: In this cross-sectional study, students enrolled in a hybrid paediatric dentistry course were asked to participate in an electronic survey. The learning environment was assessed using Distance Educational Learning Environment Survey (DELES), students' satisfaction was assessed using Satisfaction Scale (SS). Retrospective data for distance learning course was used for comparison. Ordinal data were compared using Mann-Whitney U test. Spearman's rank order correlation coefficient was used to correlate students' satisfaction with DELES. Multiple regression analysis was used to predict satisfaction. RESULTS: A total of 376 students' data were considered in the study. Hybrid learning had significantly higher scores than distance learning in 3 DELES scales. There was a statistically significant weak positive correlation between satisfaction and DELES. Multiple regression analysis model was statistically significant and accounted for (22.8%) of the variance in students' satisfaction. Only "Instructor support" (p = 0.001) and "Student autonomy" (p < 0.001) had a significant effect on satisfaction. CONCLUSION: This study supports the superiority of a hybrid learning environment over a complete distance learning environment, it also shows that satisfaction is correlated and can be predicted by the created learning environment. TRIAL REGISTRATION: This study has been registered on clinicaltrials.gov on 21 May 2020 with an identifier: NCT04401371 .

Validation of the Arabic translation of the caries impacts and experiences questionnaire for children.

BACKGROUND: The recently developed Caries Impacts and Experiences Questionnaire for Children (CARIES-QC) is originally an English questionnaire targeting the assessment of caries-related quality of life from a child's point of view. AIM: This study aimed to translate and adapt the CARIES-QC into the Arabic language and to test its reliability and validity on Arabic-speaking children. DESIGN: A total of 234 children aged 5-16 years answered the translated questionnaire. Internal consistency was measured using Cronbach's alpha; 62 children answered the questionnaire again to evaluate the test-retest reliability by calculating the intraclass correlation coefficient (ICC). Convergent validity was evaluated by correlating question scores with global question scores. Confirmatory factor analysis (CFA) was conducted to evaluate cross-cultural validity. RESULTS: Cronbach's alpha of the CARIES-QC/A was 0.905. The inter-item correlation coefficients of the CARIES-QC/A ranged from 0.240 to 0.850. The total ICC score was 0.960. CFA demonstrated acceptable fit to the data in the one-factor model. Convergent validity indicated moderate correlation with the global question (rs  = .740). CONCLUSION: The CARIES-QC/A is a valid and reliable tool that could be used to evaluate oral health-related quality of life in Arabic-speaking children.

Exploring new marine bacterial species, Alcaligenes faecalis Alca F2018 valued for bioconversion of shrimp chitin to chitosan for concomitant biotechnological applications.

The exploitation of chitinous materials seems to be an infinite treasure. To this end, using shellfish waste as the sole carbon/nitrogen source solves environmental challenges while lowering microbial chitinase production costs. Bioconversion of shellfish chitin wastes such as shrimp shells has recently been investigated for the production of enzymes and bioactive materials in order to maximize the utilization of chitin-containing seafood processing wastes. In this study, the bioconversion of chitin to chitosan by Alcaligenes faecalis Alca F2018 revealed the highest chitin deacetylase (CDA) activity of 40.6 U/µg. The resulted low Km and high Vmax values explain the high affinity of the purified CDA to the p-nitroacetanilide substrate. CDA with a molecular weight of 66 KDa was purified from F2018 strain, with a 14.5% yield. FT-IR revealed distinct chitosan peaks and XRD revealed that chitosan samples had lower crystallinity than chitin. TGA analysis revealed that the recovered chitosan samples were more thermally stable. The deacetylation degree percentages of the produced chitosan are in the same range as that of the commercial chitosan, suggesting the promising potential of A. faecalis Alca F2018 to utilize shrimp shells in their raw form in the fermentation media based on its CDA enzyme activity.

Efficacy of metal oxide nanoparticles as novel antimicrobial agents against multi-drug and multi-virulent Staphylococcus aureus isolates from retail raw chicken meat and giblets.

Staphylococcus aureus is among the most common zoonotic pathogens originating from animals consumed as food, especially raw chicken meat (RCM). As far as we know, this might be the first report that explores the efficacy of metal oxide nanoparticles (MONPs), such as zinc peroxide nanoparticles (ZnO2-NPs), zinc oxide nanoparticles (ZnO-NPs), and titanium dioxide nanoparticles (TiO2-NPs) against multidrug resistant (MDR) and/or pandrug resistant (PDR) S. aureus strains with a strong biofilm-producing ability isolated from RCM and giblets. The overall prevalence of coagulase-positive staphylococci was 21%, with a contamination level range between 102 and 104 CFU/g. The incidence of virulence genes See (21/36), pvl (16/36), clfA (15/36), sec (12/36), tst (12/36), and sea (11/36) among S. aureus strains were relatively higher those of seb, sed, fnbA, and fnbB. For antimicrobial resistance gene distribution, most strains harbored the blaZ gene (25/36), aacA-aphD gene (24/36), mecA gene (22/36), vanA gene (20/36), and apmA gene (20/36) confirmed the prevalence of MDR among S. aureus of RCM products. However, cfr (11/36), spc (9/36), and aadE (7/36) showed a relatively lower existence. The data of antibiogram resistance profiles was noticeably heterogeneous (25 patterns) with 32 MDR and four PDR S. aureus strains. All tested strains had a very high MAR index value (>0.2) except the P11 pattern (GEN, MXF, PMB), which showed a MAR index of 0.19. Among the strong biofilm-producing ability (BPA), 14 (70%) strains were isolated from wet markets, while only six strong BPA strains were isolated from supermarkets. The mean values of BPA ranged from 2.613 ± 0.04 to 11.013 ± 0.05. Clearly, ZnO2-NPs show significant inhibitory activity against S. aureus strains compared with those produced by the action of ZnO-NPs and TiO2-NPs. The results of anti-inflammatory activity suggest ZnO2-NPs as a lead compound for designing an alternative antimicrobial agent against drug-resistant and strong biofilm-producing S. aureus isolates from retail RCM and giblets.

Molecular characterization of virulence and drug resistance genes-producing Escherichia coli isolated from chicken meat: Metal oxide nanoparticles as novel antibacterial agents.

Escherichia coli is a major global foodborne pathogen, infecting a wide range of animals and contaminating their meat products. E. coli, can lead to high morbidity and mortality with a huge economic loss especially if foodborne diseases are associated with multidrug resistant (MDR)- and multivirulent-producing pathogens. Due to the increased resistance to common antimicrobials used to treat livestock animals and human infections, the discovery of new and innovative nanomaterials are in high demand. Recently, metal oxides can be considered as effective inorganic agents with antimicrobial features. Hence, this study might be the first to evaluate the efficiency of metal oxide nanoparticles (MO-NPs) as novel antibacterial agents against MDR/multivirulent E. coli pathogens isolated from chicken meat. The occurrence of pathogenic E. coli was determined in fresh warm chicken meat parts (breast, thigh, liver and gizzard). Ninety-one of 132 (69%) chicken meat parts were Escherichia -positive with E. coli as the only species isolated. Out of identified 240 E. coli strains, 72.5% (174/240) were classified as MDR E. coli strains. Fifty-five profile patterns were obtained. From each pattern, one strain was randomly selected for further analysis of virulence and resistance genes. Extracted DNA was assessed for the presence of antibiotic resistance genes (blaIMP-7, blaIMP-25, blaTEM, blaSHV, blaOXA-2, tetA, aadA, and aac(3)-IV) and virulence genes (stx1, stx2, hlyA, eaeA, aggR, eltB, estIb, papA, afa and hlyD). Clustering analyses revealed that 10 E. coli harboring the highest number of virulence and resistance genes were shifted together into one cluster designated as cluster X. The average activities of zinc peroxide nanoparticles (ZnO2-NPs) were higher than that of zinc oxide nanoparticles (ZnO-NPs) and titanium dioxide nanoparticles (TiO2-NPs) by 20% and 29%, respectively. The anti-inflammatory activity of ZnO2-NPs in comparison with aspirin was assessed using membrane stabilization, albumin denaturation, and proteinase inhibition methods. Significant anti-inflammatory activity of ZnO2-NPs was achieved at concentration levels of 500-1000 µg/ml. It seems that MO-NPs are effective alternative agents, since they exhibited a competitive antibacterial capability against MDR/multivirulent-producing E. coli pathogens isolated from chicken meat. Hence, ZnO2-NPs are a promising nanoparticles-based material for controlling foodborne pathogens, thereby valued for food safety applications.

Influence of luting cement on the clinical outcomes of Zirconia pediatric crowns: A 3-year split-mouth randomized controlled trial.

BACKGROUND: There is no scientific evidence supporting the choice of luting cement for cementation of zirconia crowns. AIM: The purpose of this split-mouth study was to compare the efficacy of using bioactive cement versus packable glass ionomer for cementation of posterior pediatric zirconia crowns. DESIGN: Fifty first mandibular primary molars were restored by zirconia crowns and were randomly divided to be luted with either (a) bioactive cement or (b) packable glass ionomer. Crowns' retention, fracture, and gingival condition were evaluated at 1 week, and 1-, 3-, 6-, 9-, 12-, 18-, 24-, and 36-month intervals. Statistical analysis was carried out using Fisher's exact test, Kaplan-Meier survival analysis, and Wilcoxon signed rank test. RESULTS: At 3- to 36-month follow-ups, there were statistically significant (P = .009-≤.001) less debonded crowns in packable glass ionomer group. There were no fractured crowns for either cements. There was no statistically significant difference between gingival index scores. CONCLUSIONS: Packable glass ionomer is more retentive than bioactive cement when used for cementing zirconia pediatric crowns. Posterior zirconia pediatric crowns have high fracture resistance after 36 months of clinical performance, irrespective of luting cement. Luting cement for zirconia pediatric crowns has no apparent effect on gingival condition around crowns.

Case Report: Root resorption caused after pulp death of adjacent primary molar.

Necrotic decayed primary molars with necrotic pulp tissues may show periapical involvement and root resorption. In this case report, a pediatric patient with a very common chief complain and clinical picture of necrotic badly decayed molar, introduced a very interesting case when radiographic investigation was performed, which showed that root resorption of the adjacent healthy molar occurred. The current report is, to the best of our knowledge, the first to report such finding in primary dentition.