Virtual Objective Structured Clinical Examination (OSCE) Training in the Pandemic Era: Feasibility, Satisfaction, and the Road Ahead.

INTRODUCTION: Objective Structured Clinical Examinations (OSCEs) are essential assessments for evaluating the clinical competencies of medical students. The COVID-19 pandemic caused a significant disruption in medical education, prompting institutions to adopt virtual formats for academic activities. This study analyzes the feasibility, satisfaction, and experiences of pediatric board candidates and faculty during virtual or electronic OSCE (e-OSCE) training sessions using Zoom video communication (Zoom Video Communications, Inc., San Jose, USA). METHODS: This is a post-event survey assessing the perceptions of faculty and candidates and the perceived advantages and obstacles of e-OSCE. RESULTS: A total of 142 participants were invited to complete a post-event survey, and 105 (73.9%) completed the survey. There was equal gender representation. More than half of the participants were examiners. The overall satisfaction with the virtual e-OSCE was high, with a mean score of 4.7±0.67 out of 5. Most participants were likely to recommend e-OSCE to a friend or colleague (mean score 8.84±1.51/10). More faculty (66.1%) than candidates (40.8%) preferred e-OSCE (P=0.006). CONCLUSION: Transitioning to virtual OSCE training during the pandemic proved feasible, with high satisfaction rates. Further research on virtual training for OSCE in medical education is recommended to optimize its implementation and outcomes.

Effect of various surface coating methods on surface roughness, micromorphological analysis and fluoride release from contemporary glass ionomer restorations.

OBJECTIVE: To evaluate the effect of various surface coating methods on surface roughness, micromorphological analysis and fluoride release from contemporary resin-modified and conventional glass ionomer restorations. MATERIALS & METHODS: A total of 72 permanent human molars were used in this study. The teeth were randomly assigned into 2 groups according to type of restorative materials used; resin modified glass ionomer cement and conventional glass ionomer (SDI Limited. Bayswater Victoria, Australia). Each group was subdivided into 3 subgroups according to the application of coat material; Sub-group1: without application of coat; Sub-group2: manufacturer recommended coat was applied and sub-group3: customized (vaseline) coat was applied. Each group was then subdivided into two divisions according to the time of testing; immediate (after 24 h) and delayed (after 6 months of storage). Three specimens from each sub-group were selected for surface roughness test (AFM) and another 3 specimens for the micromorphological analysis using scanning electron microscope (SEM). For the fluoride release test, a total of 60 cylindrical discs were used (n = 60). The discs were randomly split into 2 groups according to type of restorative materials used (n = 30); resin modified glass ionomer cement and conventional glass ionomer. Each group was subdivided into 3 subgroups (n = 10) according to the application of the coat material; Sub-group1: without application of coat; Sub-group2: with the manufacturer recommended coat and sub-group3: with application of customized (vaseline) coat. Data for each test was then collected, tabulated, were collected, tabulated, and tested for the normality with Shapiro-Wilk test. Based on the outcome of normality test, the significant effects of variables were assessed using appropriate statistical analysis testing methods. RESULTS: Regarding the data obtained from surface roughness test, Shapiro-Wilk test showed normal distribution pattern of all values (p > 0.05). Accordingly, Two-way ANOVA outcome showed that the 'type of restoration' or 'test time' had statistically significant effect on the AFM test (p < 0.05). Regarding Fluoride specific ion electrode test 2-way ANOVA followed by Least Significant Difference (LSD) Post-hoc test revealed significant difference among the groups (p < 0.05). It showed that SDI GIC group after 14 days of measurement had the highest mean of fluoride release (36.38 ± 3.16 PPM) and SDI RMGIC after 30 days of measurement had the second highest mean of fluoride release (43.28 ± 1.89 PPM). Finally, regarding the micromorphological analysis using SEM, a slight difference was observed between the studied groups. CONCLUSIONS: Based on the results of this study, various coatings enhance surface roughness in the initial 24 h of restoration insertion. Different coat types seems that have no influence on fluoride release and the micromorphological features of the restoration/dentin interface.

Effect of different storage media on elemental analysis and microhardness of cervical cavity margins restored with a bioactive material.

Objectives: This study aimed to investigate the elemental analysis and microhardness of a bioactive material (Activa) and marginal tooth structure after storage in different media. Materials and Methods: Fifteen teeth received cervical restorations with occlusal enamel and gingival dentin margins using the tested material bonded with a universal adhesive, 5 of them on the 4 axial surfaces and the other 10 on only the 2 proximal surfaces. The first 5 teeth were sectioned into 4 restorations each, then stored in 4 different media; deionized water, Dulbecco's phosphate buffered saline (DPBS), Tris buffer, and saliva. The storage period for deionized water was 24 hours while it was 3 months for the other media. Each part was analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis for different substrates/distances and the wt% of calcium, phosphorus, silica, and fluoride were calculated. The other 10 teeth were sectioned across the restoration, stored in either Tris buffer or saliva for 24 hours or 3 months, and were evaluated for microhardness of different substrates/areas. Data were analyzed using analysis of variance and Tukey's post hoc test. Results: Enamel and dentin interfaces in the DPBS group exhibited a significant increase in calcium and phosphorus wt%. Both silica and fluoride significantly increased in tooth structure up to a distance of 75 µm in the 3-month-media groups than the immediate group. Storage media did not affect the microhardness values. Conclusions: SEM-EDS analysis suggests an ion movement between Activa and tooth structure through a universal adhesive while stored in DPBS.

3-year randomized clinical trial to evaluate the performance of posterior composite restorations lined with ion-releasing materials.

To evaluate the impact of using ion-releasing liners on the 3-year clinical performance of posterior resin composite restorations after selective caries excavation with polymer burs. 20 patients were enrolled in this trial. Each patient had two deep carious lesions, one on each side of the mouth. After selective caries removal using polymer bur (PolyBur P1, Komet, Brasseler GmbH Co. KG, Lemgo, Germany), cavities were lined with bioactive ionic resin composite (Activa Bioactive Base/Liner, Pulpdent, Watertown, MA, USA) or resin-modified glass ionomer liner (Riva Light Cure, SDI, Bayswater, Victoria, Australia). All cavities were then restored with nanofilled resin composite (Filtek Z350XT, 3M Oral Care, St. Paul, MN, USA). All the tested materials were placed according to the manufacturers' instructions. Clinical evaluation was accomplished using World Dental Federation (FDI) criteria at baseline and after 6 months, 1, 2, and 3 years. Data were analyzed using Mann-whitney U and Friedman tests (p < 0.05). The success rates were 100% for all resin composite restorations either lined with ion-releasing resin composite or resin-modified glass ionomer liner. Mann-whitney U test revealed that there were no statistically significant differences between both ion-releasing lining material groups for all criteria during the follow-up periods (p > 0.05). Resin composite restorations showed acceptable clinical performance over 3 years either lined with bioactive ionic or resin-modified glass ionomer liners after selective caries excavation preserving pulp vitality. After the 3-year follow-up period, Activa Bioactive and Riva Light Cure liners were clinically effective and they exhibited with the overlying composite restorations successful clinical performance.Trial registration number: NCT05470959. Date of registration: 22/7/2022. Retrospectively registered.

Clinical performance of different bulk-fill composite resin systems in class II cavities: A 2-year randomized clinical trial.

OBJECTIVES: This study evaluated the clinical performance of bulk-fill resin composite systems with different viscosities in class II cavities. MATERIALS AND METHODS: A total of 80 class II restorations were performed with a single operator in 50 patients using four different bulk-fill resin composite materials: Filtek™ Bulk Fill, Heated Filtek™ Bulk Fill, G-aenial™ BULK Injectable, and SonicFill3. A double-blinded randomized clinical trial was designed to evaluate the two-year clinical performance of the four bulk-fill composite resins using modified FDI criteria. Data were analyzed descriptively. Level of significance was set at 0.05. Differences between groups were tested using Wilcoxon-signed-rank and Mann-Whitney-U test as nonparametric tests. RESULTS: Data were analyzed using Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed rank tests (p < 0.05). Eighty restorations were available for evaluation, with a survival function of 100%. No statistically significant differences were observed between the four groups regarding assessing esthetic, functional, and biological properties during different follow-up periods. CONCLUSIONS: After 2 years of clinical follow-up, the bulk-fill composite systems with different viscosities seem to be esthetically, functionally, and biologically acceptable, with a promising clinical performance in class II cavities.

Clinical performance of two ion-releasing bulk-fill composites in class I and class II restorations: A two-year evaluation.

OBJECTIVES: This randomized clinical trial evaluated and compared the 2-year clinical performance of two ion-releasing bulk-fill composites (Cention N and Surefil One) with that of a conventional bulk-fill resin composite (Powerfil) in Class I and II cavities. METHODS: Thirty-two patients, each with 3 Class I and/or Class II cavities under occlusion, were enrolled in this trial. A total of 96 restorations were placed, 32 for each material, as follows: a self-adhesive composite; Surefil-one, alkasite; Cention N, and a bulk-fill resin composite; Powerfil. The restorations were placed by a single operator. Clinical evaluation was performed at baseline (1-week), 6-months, 1-year, and 2-years by two independent examiners using the FDI criteria. Intergroup and intragroup comparisons were analyzed using the Kruskal-Wallis and Friedman Tests. Multiple comparisons between groups were analyzed using the Mann-Whitney and Wilcoxon-rank tests. The level of significance was set at α = 0.05. RESULTS: Twenty-seven patients with a total of 81 restorations were evaluated at the end of the 2-years with 84.35% recall rates. Clinical success rates were 100%, 100%, and 96.3% for Powerfil, Surefil-one, and Cention N, respectively. Cention N showed a statistically significant (p < 0.05) decreased marginal integrity in comparison with resin composite at the 2-year evaluation. No recurrent decay was detected in any restoration. CONCLUSIONS: Both ion-releasing bulk-fill composites provided acceptable clinical performance similar to bulk-fill composite in Class I and II restorations over a 2-year period. CLINICAL RELEVANCE: The results of this trial suggests that there is a promising evidence supporting the use of ion-releasing composites.

Clinical performance comparison between lithium disilicate and hybrid resin nano-ceramic CAD/CAM onlay restorations: a two-year randomized clinical split-mouth study.

A total of 20 lithium disilicate glass-ceramics (IPS e.max CAD, Ivoclar Vivadent) and 20 resin nano-ceramic (Voco Grandio Blocks) onlay restorations were performed in 20 patients using a split-mouth design to compare the two-year clinical performance of lithium disilicate and resin nano-ceramic onlay restorations. Both restorations were evaluated at baseline, one-year, and two-year clinical follow-ups based on the modified United States Public Health Service (USPHS) criteria. Chi-square and Fisher's exact tests showed no statistically significant difference between Voco Grandio and IPS e.max ceramic restorations for all evaluated parameters during the different follow-up periods (p > 0.05). Cochrane's and MC-Nemar's tests indicated statistically significant differences regarding color match within the Voco Grandio group. They also indicated statistically significant differences in marginal discoloration, marginal adaptation, surface texture, and postoperative hypersensitivity within both ceramic material groups (p < 0.05). Kaplan-Meier curve indicated that the survival rate of both ceramic materials was 90%. After two years of clinical service, IPS e.max CAD and Voco Grandio onlay restorations exhibited similar clinical performance.

Clinical evaluation of subgingival open sandwich restorations: 3-year results of a randomized double-blind trial.

OBJECTIVES: To provide a 3-year follow-up of previously treated patients to assess and compare the periodontal responses and clinical performance of proximal subgingival open sandwich restorations. MATERIALS AND METHODS: Ninety-five adults participated in the study, with a combined total of 120 compound Class II cavities. These cavities had gingival margins located below the CEJ. Four different restorative materials were used to elevate the dentin/cementum gingival margins of the cavities: resin-modified glass ionomer, glass hybrid, flowable bulk-fill composite, or ion-releasing material, which were then completed with the same overlaying composite. Different periodontal and clinical evaluations, based on the criteria set by the World Dental Federation (FDI) criteria, were performed at different time intervals, including baseline, 6 months, 1, 2, and 3 years. RESULTS: The type of base material did not affect the periodontal evaluations. There were no statistically significant differences between different time intervals or base material groups in any of the evaluated FDI parameters. However, the ion-releasing material scored significantly worse in the radiographic evaluation than any of the other groups. CONCLUSIONS: All tested materials are suitable for proximal subgingival open sandwich restorations, as long as the restoration/tooth margin is at least 2-mm away from the bone crest. CLINICAL SIGNIFICANCE: Clinicians can confidently choose any of the tested materials for proximal subgingival open sandwich restorations, as they have shown good outcomes from both periodontal and clinical perspectives.

Periodontal Evaluation of Subgingival Open Sandwich Restorations: 2-Year Results of a Randomized Double-Blind Trial.

This study aimed to evaluate the periodontal responses of subgingival proximal margins elevated using different restorative materials. A total of 120 proximal cavities with dentin/cementum gingival margins were elevated using one of four materials (resin-modified glass ionomer, glass hybrid, flowable bulk-fill resin composite, or bioactive ionic resin) and completed with the same overlaying resin composite. At 2 weeks (baseline), 6 months, 1 year, and 2 years postrestoration, periodontal parameters and the radiographic distance between the restoration margin and bone crest were evaluated. Appropriate statistical analyses were performed. The values of all periodontal parameters increased with time, although only the increases in Plaque Index and probing depth within each material group were statistically significant. There were no statistically significant differences in any of the periodontal parameters between the different materials within the same evaluation period, nor between different time points or material groups in the radiographic distances. Both glass ionomer-based and resin-based materials were periodontally safe as subgingival open sandwich restorations.

Prevalence of the medical student syndrome among health professions students and its effects on their academic performance.

Medical student syndrome (MSS) is health-related anxiety while studying a specific disease that leads to stress and anxiety. The study aims to determine the prevalence of MSS among health professions students to identify its effect on the student academic performance and to recognize the awareness of MSS among health professions students. This is a descriptive cross-sectional study where 544 students from King Saud University health colleges were included and filled in a self-reported designed questionnaire. We used validated scale of short health anxiety inventory closed-ended items to measure the prevalence of MSS. All statistical analyses were performed using the statistical package for social sciences statistical software package. The results showed that 8.5% of the health colleges students were affected by MSS. The students with the medical syndrome had higher levels of anxiety (anxiety-odd ratio [OR] = 1.3, P = .35; anxiety-OR = 1.57, P = .27) and hypochondriac issues (hypochondria-OR = 2.93, P = .03; hypochondria-OR = 2.61, P = .14) than other students. Concerning to MSS negative consequences, students who experienced medical syndrome most of the time and always were 1.43 and 1.45 times more likely to experience anxiety. As a result of the medical syndrome, students with a grade point average decrease of <0.20 are 3.37 times more likely to develop a hypochondriac problem than students with no grade point average decrease (OR = 3.37; P = .04). Third-year students reported more anxiety and hypochondria symptoms than other-year students. In conclusion, MSS is a growing problem in health colleges. This study showed that, academic performance was affected for the students who have MSS. The prevention of this phenomenon may be greatly enhanced by reassurance and discussions about this syndrome.

Inhibition of Caries around Restoration by Ion-Releasing Restorative Materials: An In Vitro Optical Coherence Tomography and Micro-Computed Tomography Evaluation.

The objective of this study was firstly to assess the demineralization inhibitory effect of ion-releasing restorations in enamel adjacent to restoration using a biofilm caries model and secondly to compare the effect to that in a chemical caries model. Fifty-six bovine incisors were filled with either Surefil one (SuO), Cention N (CN) (both ion-releasing materials), Ketac-Molar (GIC) or Powerfill resin composite (RC). The restored teeth were then randomly divided into 2 groups according to the used caries model (biofilm or chemical caries model). The micro-computed tomography (MicroCt) and optical coherence tomography (OCT) outcome measures used to evaluate demineralization inhibition effects were lesion depth, LD and increase in OCT integrated reflectivity, ΔIR, at five different depths. It was observed that all outcome measures of CN were statistically the same as those of GIC and conversely with those of RC. This was also the case for SuO except for LD, which was statistically the same as RC. When comparing the two caries models, LD of the biofilm model was statistically deeper (p < 0.05) than the chemical model for all four materials. In conclusion, CN and SuO have similar demineralization inhibitory effects as GIC, and the biofilm caries model is more discriminatory in differentiating demineralization inhibitory effects of ion-releasing restorative material.

Impact of corticosteroid administration on the response of exposed dental pulp to capping with bioactive cements-experimental study on mongrel dogs.

BACKGROUND: Corticosteroids are commonly used as a treatment for a variety of pathological conditions, however, systemic corticosteroid administration has adverse effects including impaired immune response and wound healing. Such complications may affect pulp healing after direct pulp capping. The current study evaluated the influence of corticosteroids on the healing ability of exposed dogs' dental pulps after direct pulp capping (DPC) with bioactive materials. METHODS: Ten healthy male dogs were assigned randomly into two groups, 5 dogs each: group I represent the control group which did not receive any medication, and group II was given corticosteroid for 45 days before DPC and till the dogs were euthanized (n = 75 teeth for each group). Following mechanical exposure, the pulps were randomly capped with either Ca(OH)2, MTA, or Biodentine. The pulpal tissues' reaction to the capping materials was evaluated 65 days postoperatively according to the following parameters: calcific bridge formation, pulpal inflammation, pulp necrosis, and bacterial infiltration. RESULTS: The corticosteroid-treated group revealed no significant difference compared to the control group concerning the pulp healing response (P > 0.05). Both Biodentine and MTA-treated specimens revealed significant differences with Ca(OH)2-treated specimens (P < 0.05) which displayed a superior positive effect of both MTA and Biodentine to Ca(OH)2 regarding all the parameters. CONCLUSIONS: Direct pulp capping technique whenever indicated in subjects treated with corticosteroid immunosuppressive drugs like prednisone performed well in aseptic conditions especially when capped with bioactive materials.

In vitro elemental and micromorphological analysis of the resin-dentin interface of bioactive and bulk-fill composites.

PURPOSE: To evaluate the bonding interface and the remineralization potential of a bioactive restorative material on demineralized dentin compared to a conventional bulk-fill resin composite restoration. METHODS: Twelve caries-free human molars were used in this study. Specimens were randomly divided into two groups according to the type of restorative material used (n=12); an injectable resin-modified glass-ionomer restorative [Activa BioActive-Restorative (ABR) ] and a bulk-fill composite [3M Filtek One Bulk Fill Restorative, (BFC) ]. Each restored specimen was sectioned in two semi-equal halves along the long axis of the teeth perpendicular to the resin dentin interface with a water-cooled diamond disk at low speed. The restoration-dentin interfaces were scanned under SEM to observe micromorphological analysis; then an elemental analysis of the interface was performed using an energy dispersive X-ray (EDX) spectroscopy. RESULTS: Quantitative data were described using median (minimum and maximum) after testing normality using the Shapiro-Wilk test. Mann-Whitney U test was used to compare the BFC and ABR. Higher mean values of Ca were identified and related to the ABR material, which provided more Ca ions than BFC. The comparison of Ca and P between materials showed a significant difference in the amount of Ca provided by ABR versus BFC. ABR restorations presented a thicker, and superior remineralization interface compared to the bulk-fill resin composite. CLINICAL SIGNIFICANCE: Activa BioActive Restorative restorations presented a thicker and superior remineralization interface compared to the bulk-fill resin composite.

Effect of shelf-storage temperature on degree of conversion and microhardness of composite restorative materials.

BACKGROUND: The pre-cure temperature is considered an important parameter that affects the polymerization kinetics and the properties of composite restoration. As dissension exists about the effect of storing composite restorative materials in refrigerator, this study aimed to assess the effect of shelf-storage temperature on degree of conversion (DC) and microhardness of three composite restorative materials with different matrix systems. METHODS: Three commercially-available composite restorative materials were used in this study; an Ormocer-based composite (Admira Fusion, Voco GmbH), a nanoceramic composite, (Ceram.X SphereTEC One, Dentsply Sirona GmbH), and a nanohybrid composite (Tetric N-Ceram, Ivoclar Vivadent AG). Regarding DC and microhardness tests, 60 disc-shaped composite specimens for each test were randomly divided into 3 groups (n = 20) according to the restorative material used. Each group was divided into 2 subgroups (n = 10) according to the composite storage temperature; stored at room temperature or stored in the refrigerator at 4°-5 °C. DC was evaluated using a Fourier-transform infrared spectrometer coupled to an attenuated total reflectance accessory. Microhardness was evaluated using micro-Vickers hardness tester under a load of 50 g with a dwell time of 10 s. The results were analyzed by ANOVA, post-hoc LSD, and independent t-tests at a significance level of p < 0.05. RESULTS: Regarding DC test all groups showed statistically significant differences at both storage temperature. The Ormocer-based composite had the highest mean values. There was a statistically significant difference between all room-stored groups and their corresponding groups stored at refrigerator (p < 0.05). For microhardness test, all groups exhibited also statistically significant differences at both storage temperatures with the Ormocer-based composite having the highest mean values. A statistically significant difference between both room-stored and refrigerator-stored groups has been observed also (p < 0.05). CONCLUSIONS: Refrigeration of resin-composite might have a deleterious effect on DC and microhardness of the tested composite restorative materials with different matrix systems. Moreover, the differences in the formulations of composite matrix have a potential impact on DC and microhardness.

Five-year randomized clinical trial to evaluate the clinical performance of high-viscosity glass ionomer restorative systems in small class II restorations.

OBJECTIVE: Evaluate and compare the 5-year clinical performance of three high-viscosity glass ionomer restorative materials in small class II restorations. MATERIALS AND METHODS: Forty patients, each with four class II restorations, were enrolled in this trial. A total of 160 restorations were placed, 25% for each material, as follows: three high-viscosity conventional glass ionomer restorative systems (Ketac Universal Aplicap, EQUIA Forte and Riva Self Cure HV) and a microhybrid resin composite system (Filtek Z250). Clinical evaluation was performed at baseline and after 1, 3, and 5 years by two independent examiners using FDI criteria. Epoxy resin replicas were observed under scanning electron microscope (SEM) to examine surface characteristics. Data were analyzed with Kruskal-Wallis, Mann-Whitney U, Friedman, and Wilcoxon signed-rank tests (p < 0.05). RESULTS: The success rates were 100% for resin composite, 97.4% for Ketac Universal, and 94.9% for both EQUIA Forte and Riva HV restorations. Statistically significant differences were observed between all groups in terms of surface luster and color match criteria (p < 0.05). Statistically significant changes were found over time for all criteria except for fracture of material, postoperative hypersensitivity, recurrence of caries, tooth integrity, periodontal response, adjacent mucosa, and oral health criteria (p > 0.05). SEM evaluations were in accordance with the clinical findings. CONCLUSIONS: Although drawbacks in surface luster and color match appeared over the 5-year evaluation period, the three high-viscosity glass ionomer restorative materials provided successful clinical performance in small to medium sized class II cavities compared to microhybrid resin composite. CLINICAL SIGNIFICANCE: Glass ionomer restorations exhibited clinical performance similar to that of microhybrid resin composite restorations in small class II cavities subsequent to 5-year evaluation.

Periodontopathic bacterial adhesion to different restorative materials used to elevate proximal subgingival margins.

This study compared the periodontopathic bacterial adhesion to four restorative materials used for deep margin elevation at 2, 24, and 48-h after incubation. Discs were produced from four restorative materials: resin modified glass ionomer, glass hybrid, flowable bulk fill resin composite, and bioactive ionic resin. Root dentin was used as control. Specimens were coated with saliva and used to culture a biofilm comprised of three strains of periodontopathic bacteria; Porphyromonas gingivalis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans. Bacterial adherence was assessed by colony count assay, crystal violet staining, and visualized using confocal laser scanning microscopy. Data were analyzed by two-way ANOVA followed by Tukey's post hoc tests. The adhesion values for the control specimens were significantly higher than for other materials, while those for the flowable bulk fill were significantly lower than for any other material within all evaluation assays. The 2-h incubation period showed the lowest adhesion values regardless of the group. The 48-h adhesion values were higher than the 24-h results in all groups except the flowable bulk fill. Microscopic imaging partially supported the findings of the measurements. In terms of periodontopathic bacterial adhesion, the tested flowable bulk fill may be preferable for subgingival use over other tested materials.

Microshear Bond Strength of Bioactive Materials to Dentin and Resin Composite.

OBJECTIVES: The aim of this study was to comparatively evaluate microshear bond strength (µSBS) of bioactive ionic resin composite and resin-modified glass ionomer liner (RMGI) to dentin and resin composite. MATERIALS AND METHODS: The enamel of 11 posterior molar teeth was removed to expose dentin and then placed in acrylic blocks. Each specimen received three microcylindrical Tygon tubes filled with bioactive ionic resin composite (Activa Bioactive base/liner (PULPDENT: , MA, USA)), RMGI (Riva light cure SDI LTD, Bayswater, Australia), and resin composite (Filtek Z350xt, MN, USA). Composite discs (n = 11) were fabricated from nanofilled resin composite (Filtek Z350xt) and then fixed in acrylic blocks. Each specimen received two microcylindrical Tygon tubes filled with Activa Bioactive base/liner and Riva RMGI. All specimens were mounted individually to universal testing machine for µSBS test. Failure modes were analyzed using stereomicroscope and scanning electron microscope. RESULTS: Filtek Z350xt nanofilled resin composite showed the highest µSBS values. No statistical significant difference was found between Activa Bioactive and Riva RMGI (p > 0.05). CONCLUSION: Bioactive ionic resin composite liner exhibited similar bond strength as RMGI to dentin and resin composite.

Correlation between different methodologies used to evaluate the marginal adaptation of proximal dentin gingival margins elevated using a glass hybrid.

Objectives: This study aimed to evaluate the effect of aging on the marginal quality of glass hybrid (GH) material used to elevate dentin gingival margins, and to analyze the consistency of the results obtained by 3 in vitro methods. Materials and Methods: Ten teeth received compound class II cavities with subgingival margins. The dentin gingival margins were elevated with GH, followed by resin composite. The GH/gingival dentin interfaces were examined through digital microscopy, scanning electron microscopy (SEM) using resin replicas, and according to the World Dental Federation (FDI) criteria. After initial evaluations, all teeth were subjected to 10,000 thermal cycles, followed by repeating the same marginal evaluations and energy dispersive spectroscopy (EDS) analysis for the interfacial zone of 2 specimens. Marginal quality was expressed as the percentage of continuous margin at ×200 for microscopic techniques and as the frequency of each score for FDI ranking. Data were analyzed using the paired sample t-test, Wilcoxon signed-rank test, and Pearson and Spearmen correlation coefficients. Results: None of the testing techniques proved the significance of the aging factor. Moderate and strong significant correlations were found between the testing techniques. The EDS results suggested the presence of an ion-exchange layer along the GH/gingival dentin interface of aged specimens. Conclusions: The marginal quality of the GH/dentin gingival interface defied aging by thermocycling. The replica SEM and FDI ranking results had stronger correlations with each other than either showed with the digital microscopy results.

Effect of different surface treatments on resin-matrix CAD/CAM ceramics bonding to dentin: in vitro study.

BACKGROUND: Evaluating the effect of different surface treatment methods on the micro-tensile bond strength (µTBS) of two different resin-matrix computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics (RMCs). METHODS: A standardized inlay preparations were performed on 100 intact maxillary premolars. According to the type of the restorative material, the teeth were randomly divided into two equally sized groups (n = 50): (polymer-infiltrated ceramic (Vita Enamic) and resin-based composites (Lava Ultimate)). The inlays were fabricated using CAD/CAM technology. In each group, the specimens were randomly assigned to five subgroups (n = 10) according to the surface treatment method: group 1 used was the control group (no surface treatment); group 2, was treated with air abrasion with 50 µm Al2O3 (A) and universal adhesive (UA); group 3, was treated with air abrasion with 50 µm Al2O3 (A) and silane coupling agent (S); group 4, was treated with hydrofluoric acid (HF) and universal adhesive (UA) and group 5, was treated with Hydrofluoric acid (HF) + silane coupling agent (S). The inlays were then cemented to their respective preparations using dual-cure self-adhesive resin cement (RelyX U200, 3 M ESPE) according to the manufacturer's instructions. The µTBS test was conducted in all groups, and stereomicroscope and scanning electron microscope were used to inspect the failure mode. The data were statistically analyzed using a two-way analysis of variance (ANOVA) and Tukey's post-hoc multiple comparison tests at a significance level of p < 0.05. RESULTS: Surface treatments significantly increased the µTBS of the materials compared to the control group (p < 0.05). For CAD/CAM RBCs, the µTBS value highest in group 2 whereas, for PICN, the µTBS value was highest in group 3. Cohesive failure of CAD/CAM restorative material was the most predominant mode of failure in all treated groups, whereas adhesive failure at restoration-cement interface was the most predominant failure mode in the control group. CONCLUSION: Surface treatments increase the µTBS of resin-matrix CAD/CAM ceramics to tooth structure. Air abrasion followed by universal adhesive and hydrofluoric acid followed by silane application appears to be the best strategies for optimizing the bond strength of CAD/CAM RBCs and PICN respectively.

Secondary caries and marginal adaptation of ion-releasing versus resin composite restorations: a systematic review and meta-analysis of randomized clinical trials.

This systematic review was aimed to evaluate occurrence of secondary caries and marginal adaptation in ion-releasing materials versus resin composite. Electronic search of PubMed, Scopus, and Open Grey databases with no date or language restrictions until May 21st, 2021, was conducted. Randomized clinical trials that compared ion-releasing restorations versus resin composite were included. For quantitative analysis, a random-effects meta-analysis with risk difference as an effect measure and a 95% confidence interval was used. Quality of evidence was assessed using The Grading of Recommendations, Assessment, Development, and Evaluation criteria. The risk of bias was evaluated using the Cochran Collaboration Risk of Bias tool. The inclusion criteria were met by 22 studies, and 10 studies were included in the meta-analysis. Three follow-up periods (1 year, 18 months-2 years, and 3 years) were evaluated. The overall quality of evidence for secondary caries and marginal adaptation outcomes was low. The results of the meta-analysis showed no significant difference (p > 0.05) in both outcomes between ion-releasing materials and resin composite. The occurrence of secondary caries was not dependent on the nature of the restorative material. It is more likely a complex process that involves the same risk factors as primary carious lesions.