Hani Mohammed Nassar

Glass ionomer cements (GICs) are considered functionally biomimetic as they participate in ion-exchange processes that partially resemble the behavior of natural enamel and dentin, chemically bond to dental hard tissues, and release fluoride. While GICs are designed to interact with aqueous oral environments, their exposure to dietary beverages may affect their esthetic stability and water-related behavior within the oral environment. For biomimetic restorative materials to perform successfully in the oral environment, they must maintain not only bioactive properties but also esthetic stability and resistance to water-related degradation during exposure to dietary beverages. This study evaluated beverage-induced color changes, water sorption, and water solubility of six GICs following their immersion in coffee, tea, berry juice, cola, and distilled water (n = 5 per material per solution). Color measurements were recorded at baseline and after 2, 4, 6, and 8 weeks using a spectrophotometer, and color change (ΔE) values were calculated using the CIE L*a*b* system. Specimen mass was measured at baseline, after 8 weeks of immersion and then after 4 weeks of desiccation. Data were analyzed using repeated-measures Analysis of Variance (ANOVA) and Fisher’s least significant difference post hoc tests (α = 0.05). The results showed time, material, and solution significantly affected ΔE (p < 0.001). Tea produced the greatest discoloration overall, followed by coffee. ChemFil exhibited the greatest staining susceptibility, while Fuji II showed the lowest staining susceptibility. Water sorption and solubility were material- and solution-dependent. Clinically relevant discoloration of GICs was found when immersed in common beverages over time, with tea showing the strongest staining effect. These findings indicate that although GICs exhibit biomimetic characteristics through their interaction with tooth structures and aqueous environments, their long-term esthetic stability and resistance to environmental challenges should also be considered when selecting restorative materials for clinically visible areas.

Background: The aesthetic performance of single-shade polymer-based restorative materials (SPRs) can be compromised by extrinsic stains. Understanding the effects of novel whitening interventions on SPRs is crucial. Objective: This in vitro study aimed to evaluate the effects of different whitening interventions, including a novel purple tooth serum and charcoal-based whitening toothpaste with and without in-office bleaching, on the color of a new coffee-stained SPR. Materials and Methods: Seventy disc-shaped SPR specimens were prepared, stained, and then divided into seven groups (n = 10). Three groups were subjected directly to 2500 cycles of brushing simulation with regular toothpaste (control), charcoal toothpaste, or purple tooth serum. The rest were divided into bleaching groups, and the four groups underwent a simulation of bleaching and then brushing with the three products. The color parameters were recorded at the stained baseline, after brushing, after bleaching, and after post-bleaching brushing. The color change (ΔE00) was calculated, and the data were analyzed statistically using the Kruskal–Wallis test and Dunn–Bonferroni pairwise comparisons (p < 0.05). Results: In-office bleaching without brushing had a statistically significantly higher ΔE00 value than all other groups (p < 0.001). Post hoc tests indicated that the ΔE00 values of the brushed specimens were not significantly different from each other when assessed with and without bleaching (p > 0.05). When using the charcoal toothpaste, the post-bleaching brushed specimens had a noticeable color change above the PT. Conclusions: Bleaching improved the stained SPR color initially, but other treatments may offer longer-lasting aesthetics. The charcoal toothpaste showed promising results when combined with bleaching. The purple serum showed limited effectiveness.

This study investigated the prevalence of water filtration and purification systems [WFPSs] in Jeddah, Saudi Arabia, and the impact of WFPSs on mineral concentrations in tap water. A convenience sample of residents completed a questionnaire on water usage/sources and provided water samples. Water was analyzed [fluoride—ion-specific electrode; metals—atomic absorption spectrometry]. Nonparametric testing was performed to compare mineral concentrations between different water sources, and questionnaire associations underwent correlation tests. Ninety-nine participants completed the study. Sixty percent reported using some type of WFPS. The most used WFPSs were reverse osmosis [RO] systems [62%], followed by whole-house carbon filters [8%] and faucet-mounted filters [6%]. Fluoride concentrations were very low across all WFPSs [all median; RO—0.02 ppm, other WFPS—0.01 to 0.05 ppm] and in unfiltered tap water [0.02 ppm]. RO systems reduced the concentrations of several minerals [magnesium—1.40 ppm, p = 0.006; potassium—0.55 ppm, p = 0.016; sodium—7.88 ppm, p = 0.001] compared to those in unfiltered tap water [magnesium—1.8 ppm; potassium—0.62 ppm; sodium—10.60 ppm]. However, RO systems did not affect calcium concentrations [10.93 ppm] compared to those in unfiltered tap water [11.47 ppm]. Participants with larger households were significantly more likely to use tap water treatment systems [p = 0.002]. The observed reduction in certain mineral concentrations raises concerns about potential nutritional implications.

Objectives: To investigate the effect of water filter pitchers on the concentration of different minerals in tap water.Methods: Nine water filter pitchers (A–I) were chosen based on consumer preferences and Amazon reviews. Each filter was tested for its ability to modify the concentrations of fluoride, calcium, magnesium, potassium, and sodium in tap water. Tap water samples were collected before and after filtration, at various intervals (1, 5, 10, 30, 50, 75, and 100 L) during filtration, and analyzed using an ion‐specific electrode (fluoride) and atomic absorption spectrometry (other minerals). Statistical analyses were conducted to compare filtered and unfiltered water mineral concentrations.Results: Water filter pitcher effect: Filters F (p < 0.001) and G (p = 0.030) decreased fluoride concentrations. All filters except I (p = 0.235) and H (p = 0.717) decreased calcium concentrations (p < 0.01). Filters E (p = 0.018), D (p = 0.014), and G (p = 0.010) decreased magnesium concentrations. Filters I (p = 0.028) and D (p = 0.009) increased potassium concentrations. Filter A (p = 0.002) increased sodium concentrations, while C (p = 0.034) decreased sodium concentrations. Effect of filter aging: All filters affected mineral concentrations over time but to varying extents. Filter G had the most pronounced effect on reducing mineral concentrations compared to all others. No filter was able to completely remove fluoride from tap water, contrary to the claims made by three manufacturers.Conclusions: The present study highlighted that water filter pitchers vary greatly in their ability to affect mineral concentrations in tap water during their use. Further research is needed to develop more effective water treatment solutions.

Purpose: The aim of this study was to analyze the stress distribution of fiber‐reinforced composite provisional fixed partial denture utilizing a finite element analysis model.Material and methods: Three anterior teeth were collected: upper right central, left central, and right lateral incisors. A fiber‐reinforced composite strip was applied to the palatal surfaces of the teeth. Micro‐computed tomographic scans were acquired of the models in order to generate three‐dimensional geometrical replicas. Finite element analysis was used to assess the stress distribution of fiber‐reinforced composite provisional fixed partial denture using different pontic types under static applied forces that were 100, 30, and 0 N.Results: The maximum stress values were found on the unprepared natural pontic. Stress values ranged from 92.2 to 909.8, 116.4 to 646.7, and 93.8 to 393.5 MPa for composite, naturally prepared, and natural unprepared pontic, respectively.Conclusions: Using unprepared natural tooth pontic in anterior provisional fixed partial denture to replace missing central incisors is considered superior to other types in terms of stress distribution.

Objectives: Approaches for combining scores have been based on weighted mean (WM) without consideration for psychometric characteristics of each individual assessments. This study evaluates consequences of WM and composite score (CS) approach.Methods: Data from two longitudinal cohorts (n = 219) were utilized for performance in three Operative Dentistry courses as basis to compare the two score‐combining methods. Four assessments (two written and two practical exams) from each course were combined using WM and CS approaches. WM scores were calculated by multiplying the score by its weight and summing across assessments. The CS approach follow a modification of the Kane and Case method, by standardizing scores, taking into account the reliability and associations between each assessment score. t‐Tests and Pearson's correlation were used to evaluate the consequences of the WM and CS approaches. In addition, changes in each student's rank across WM and CS were determined.Results: Combining scores using CS method produced lower scores and higher percentage failure in all courses compared to WM. Students ranks were changed significantly when CS was used with only 15% of the cohorts retained their ranks.Conclusions: CS produced a composite that is correlated with WM but still being substantively different providing meaningful and psychometrically rigorous information.

This investigation aimed to assess the shear bond strength and fluoride-releasing capabilities of Clearfil Universal Bond Quick (Kuraray Noritake Dental Inc., Tokyo, Japan). Forty-four extracted primary molars were divided into two groups, and the enamel substrate was prepared for evaluating shear bond strength. Scotchbond (3M ESPE) and Clearfil UBQ were used to bond composite-to-enamel substrates in each group (n = 22). Shear bond strength was measured using a universal testing device and compared. Sixteen discs (6 mm diameter and 3 mm thickness) were fabricated from each Clearfil UBQ, Fuji IX, and Fuji II LC. Over the course of 30 days, each materials’ fluoride release was examined and compared using ion analysis. Results revealed that Clearfil UBQ had statistically similar shear bond strength to Scotchbond. Between the three materials, Clearfil UBQ had the lowest fluoride release at baseline (0.11 ± 0.25) and the lowest cumulative fluoride release (0.12–0.27 ppm) over 30 days. Fuji IX had the highest fluoride release at baseline (19.38 ± 2.50) and cumulatively (40.87 ± 4.03 ppm), followed by Fuji II LC. We conclude that Clearfil UBQ and Scotchbond showed comparable bond strengths to the enamel. Fluoride release was seen in Clearfil UBQ in the initial two days of the 30-day period. The amount of fluoride release was significantly less than with glass ionomer cements.

Bulk-fill (BF) dental resin composites are made to be polymerized in increments of up to 5 mm rather than the 2 mm increment recommended for conventional composites. This project aimed to determine microhardness (MH) profiles of BF resin composites at different depths and varying light cure (LC) distances from the light source in an attempt to mimic varying clinical situations. Forty-eight cylindrical specimens (4 mm diameter and 6 mm height) were prepared from 3 BF composites: Tetric N-Ceram Bulk-Fill (TBF), Filtek One Bulk-Fill (FBF), and Sonic-Fill 2 (SF2). Four different distances (0, 2, 4, and 6 mm) from the LC unit were investigated. Vickers MH was measured at the top and bottom of the samples and at every 1 mm, by creating 3 indentations at each depth. The bottom-top microhardness ratio (MHR) and percentage reduction in MHR were also measured. Data was analyzed using mixed-model repeated-measure ANOVA at 0.05 significance level. The main variables effects “material, LC distance, and depth” were significant (p < 0.001). Increasing LC distance and the depth of the tested BF significantly affected Vickers MH and MHR. None of the tested BF materials had sufficient MHR at the depths of 4–6 mm. SF2 showed the least MHR reduction.