Analysis of changes in gingiva-occlusal parameters as perceived by three Middle-East population.

Purpose. This study aims to compare the effect of various smile parameters (buccal corridor, gummy smile, midline to face discrepancy, with and without upper lip filling) on the perception of smile attractiveness by applying the digital modification of images judged by laypersons from different Middle East populations. Materials and Methods. One hundred and eighty participants are divided into 3 groups (n=60: 30 men and 30 women): Lebanese, Syrian, and Egyptian laypersons. A frontal photo of a woman\u27s smile is manipulated with Photoshop to modify each smile parameter gradually into 3 grades. The total number of smiles assessed is 18. In addition, each evaluator must indicate which feature she or he finds most attractive in a face. Analysis of repeated measures variances followed by univariate analyses and multiple comparisons of Bonferroni are performed. Results: Eyes and smile are the most attractive elements in the face. For midline to face discrepancy, only Lebanese laypeople and Egyptian women prefer the coincidence of the midline to face compared with other positions with significant difference (p value 0.05). Concerning the buccal corridor, its size does not influence smile attractive (p value\u3e 0.05). Upper lip filling affected the perception of smile aesthetics for the midline (for Syrians and Egyptians). Conclusion: Sex and culture affect the perception of the smile attractiveness for certain parameters. Alteration of the buccal corridor does not seem to influence the smile attractiveness. Upper lip filling may be advantageous in some cases and unfavorable in others. Clinical significance: Dentists should take into consideration cultural differences when restoring smile aesthetics

A Src inhibitor regulates the cell cycle of human pluripotent stem cells and improves directed differentiation

Driving human pluripotent stem cells (hPSCs) into specific lineages is an inefficient and challenging process. We show that a potent Src inhibitor, PP1, regulates expression of genes involved in the G1 to S phase transition of the cell cycle, activates proteins in the retinoblastoma family, and subsequently increases the differentiation propensities of hPSCs into all three germ layers. We further demonstrate that genetic suppression of Src regulates the activity of the retinoblastoma protein and enhances the differentiation potential of hPSCs across all germ layers. These positive effects extend beyond the initial germ layer specification and enable efficient differentiation at subsequent stages of differentiation

Quantitative Measurements of the Depth of Enamel Demineralization before and after Bleach: An In Vitro Study

Objective. This study is aimed at determining two main points. First, if the Canary System™ (CS), initially used to assess caries, can measure a decalcification depth of bleached enamel quantitatively, and second, whether or not whitening has a harmful effect on enamel. This device can be considered a useful tool in the clinical assessment of the progression of demineralization after bleaching. Materials and Methods. This study collected sixty human premolars that are in a good state recently extracted for orthodontic reason. To properly disinfect and preserve the premolars, they were stored in a saline solution and later in distilled water for a period of two weeks to allow the premolars to rehydrate. Later, 24 hours before the experiment, the premolars were introduced into a solution of artificial saliva to acquire back their minerals. The mineral content of the teeth was measured by the Canary System™ before bleaching. The teeth were bleached with 30% hydrogen peroxide (fläsh HP 30%), 30 min per week and for 3 consecutive weeks to simulate the conditions of strong bleaching in the clinic. The extent of demineralized enamel was measured by the Canary System™ at three points on the enamel surface of each tooth. The data were averaged for each application of the bleaching product. The demineralization extent of the teeth was measured by the Canary System™ before and after bleaching. The significance level was set at 0.05, and SPSS version 26 was used. The data were analyzed by using Wilcoxon’s and Student’s tests. Results. Mineral loss occurred after the first bleaching session; the Canary System™ detected a decalcification in the first bleaching session ( μm) compared to the other sessions (), while no significant change was detected between the second and the third sessions (). Conclusion. Based on the findings of the present study, under in vitro conditions, it was possible to measure the demineralization extent of bleached enamel with the Canary System™

In vitro evaluation of the color stability and surface roughness of a new composite flow

The aim of this study was to evaluate the color stability and the surface roughness of a bulk-fill composite flow (SDR® Plus) by comparison to an ORMOCER-based composite (Ceram.x® Universal SphereTEC?) in order to confirm the validity of using SDR® Plus

Changing Trends in Eye-Related Complaints Presenting to the Emergency Department in Beirut, Lebanon, over 15 Years

Objective. To report the 15-year trend in ophthalmic presentations to the emergency department (ED) at the only medical center in Lebanon that provides 24-hour ophthalmologic care. Methods. Retrospective review of 1967 patients presenting to the ED with eye-related complaints between September 1997 and August 1998 and between September 2012 and August 2013. Diagnoses were classified into 4 categories according to the International Society of Ocular Trauma and include penetrating eye injuries, nonpenetrating eye trauma, nontraumatic ophthalmic emergencies, and nontraumatic, nonurgent ophthalmic conditions. Results. One thousand sixty eye-related presentations out of 39,158 total ED visits (2.71%) presented in 1997 compared to 907 out of 46,363 in 2012 (1.96%). Penetrating and nonpenetrating eye emergencies decreased between 1997 and 2012 (7.17% to 4.19%, p=0.003 and 52.64% to 29.00%, p<0.001, resp.) while nonurgent cases increased from 30.19% to 53.47% (p<0.001). 57% of patients were covered by third-party guarantors in 1997 versus 73% in 2012. Conclusion. Our results demonstrate a significant increase in nonurgent cases in parallel with the proportion of third-party payers, an issue to be addressed by public health policies and proper resource allocation. A detailed nationwide review is needed to make solid recommendations for the management of ophthalmologic presentations in the ED

A Two-Year Comparative Evaluation of Clinical Performance of a Nanohybrid Composite Resin to a Flowable Composite Resin

Objective: This prospective in vivo study aimed to compare the clinical behavior of a flowable composite resin (Genial Universal Flo, GC) and a nanohybrid universal composite resin (Tetric Evo Ceram, Ivoclar Vivadent) used in Class I and II direct esthetic restorations in posterior teeth. Methods: A total of 108 Class I and II direct restorations were performed in patients aged between 20 and 60 years. The originality of this study lies in the fact that both materials were placed in pairs, in the same clinical environment (i.e., the same patient and the same type of tooth). The evaluations were performed now of restoration and after 2-weeks, 6-, 12-, and 24-months intervals using clinical examination, clinical photographs, and radiological examination, according to modified USPHS criteria. Statistical analysis was performed using the Fisher exact test and chi-square analysis. Results: At baseline, the universal composite resin showed better esthetic properties such as surface luster, surface staining marginal staining. Both materials regressed significantly over time with no significant difference between groups. Conclusions: Both flowable and nanohybrid composite resins exhibit acceptable clinical performance. The present 24 months of evaluation of different composites showed that the G-ænial Universal Flo could be an effective esthetic material for posterior restoration. No significant difference between both materials over time concerning surface luster, surface staining, and marginal staining