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Pressable ceramic restorations have been introduced and investigated, and found comparable to CAD/CAM ceramic in terms of mechanical properties; however, the effect of toothbrushing on the pressable ceramic has not been thoroughly investigated. The objective of the current study was to assess the effect of artificial toothbrushing simulation on the surface roughness, microhardness, and color stability of different ceramic materials. Three lithium disilicate-based ceramics (IPS Emax CAD [EC], IPS Emax Press [EP]; (Ivoclar Vivadent AG), and LiSi Press [LP] (GC Corp, Tokyo, Japan)) were examined. For each ceramic material, eight bar-shaped specimens were prepared and subjected to 10,000 brushing cycles. Surface roughness, microhardness, and color stability (∆E) were measured before and after brushing. Scanning electron microscopy (SEM) was used for surface profile analysis. The results were analyzed using one-way ANOVA, Tukey's post hoc test, and paired sample t-test α = 0.05. The findings revealed a non-significant decrease in the surface roughness of EC, EP, and LP groups (p > 0.05), and both LP and EP have the lowest surface roughness values (0.64 ± 0.13, 0.64 ± 0.08 µm) after brushing, respectively. Toothbrushing showed a decrease in the microhardness of the three groups: EC and LP, p < 0.001; EP, p = 0.012). EP showed the lowest hardness value after brushing (862.45 ± 273.83). No significant changes (∆E) were observed in all groups (p > 0.05); however, the EC group was found to be considerably affected by color changes, in comparison to the EC and LP groups. Toothbrushing had no effect on surface roughness and color stability of all tested materials, but it decreased the microhardness. Material type, surface treatments, and glazing of ceramic materials contributed to the surface changes in the ceramic materials, necessitating further investigations in terms of the toothbrushing effect with different glazing as variables.
RESUMO
Objectives: This investigation was carried out to examine the influence of thermocycling aging on the surface roughness (Ra, µm), color parameters (L*, a*, b*), lightness change (ΔL*), chroma change (ΔC*ab), color change (ΔE), and microhardness (VH) of three lithium disilicate ceramics. Materials and methods: Forty-five specimens were prepared from three lithium disilicate materials (n = 15)-e.max CAD (EC), e.max Press (EP), and GC Initial LiSi Press (LP) ceramics-with dimensions of 6.0 × 1.2 × 16.0 ± 0.2 mm following the manufacturers' instructions. All specimens were exposed to 5000 thermal cycles with bath temperatures ranging between 5 °C and 55 °C. Data of surface roughness, color parameters, and microhardness were obtained using an optical profiler, a spectrophotometer, and a Vickers hardness tester, respectively. One-way ANOVA, a post-hoc Tukey's test, and a paired sample t-test were implemented for statistical analysis (p ≤ 0.05). Results: For surface roughness, insignificant differences were reported between the materials either before or after thermocycling (p > 0.05) while each material displayed a significant increase after being subjected to thermocycling (p < 0.05). For color parameters, LP showed significantly lower L* and b* after thermocycling while EC presented a significant reduction in a* in comparison with other materials (p < 0.05). EP showed a significant decrease in ΔL*, ΔC*ab and ΔE compared with other materials (p < 0.05). Regarding microhardness, LP showed significantly increase value in comparison with other materials (p < 0.05). Conclusions: Thermocycling had a major impact on the surface roughness, microhardness and optical characteristics of the tested materials. E.max Press displayed less changes in (ΔL*), (ΔC*ab) and (ΔE), while GC LiSi Press had better behavior in terms of microhardness.
RESUMO
Background: Diabetic emergencies are serious acute life-threatening complications of diabetes mellitus (DM). The Hajj season requires the health system in Saudi Arabia to prepare efficiently for the healthcare of millions of pilgrims, particularly for diabetic emergencies. Thus, diabetic emergencies need rapid recognition, diagnosis and treatment. This study aimed to explore the frequency and associated factors of diabetic emergencies among the pilgrim's patients with DM during Hajj, Mecca 2019. Methods: This is a prospective study which was conducted on 153 patients with DM. They were selected from three major healthcare-providing facilities during Hajj, which are Arafat, Muzdelefah and Muna healthcare centres. The study was conducted from Aug 5 to 12, 2019. All the patients who presented with any of the hypoglycaemic or hyperglycaemic emergencies had their demographic and clinical characteristics recorded to estimate the prevalence of each emergency and identify its significant associated factors. Result: More than 90% of the study participants were patients with type 2 diabetes mellitus (T2DM), while around 7% had type 1 diabetes mellitus (T1DM). Diabetic ketoacidosis (DKA) and hyperosmolar hyperglycaemic state (HHS) and hypoglycaemia were presented in (n = 11, 7.2%), (n = 19, 12.4%) and (n = 28, 18%), respectively, of the participants. Moreover, the study found that "younger age" (odds = 30.4, P = 0.0115) and "type of medication" are significantly associated with DKA. Furthermore, "older age", "type of medication", "having Cardiovascular Disease (CVD)" and "diabetes duration" were found to have a significant association with HHS. Moreover, hypoglycaemia was associated with neuropathy complication (odds = 3.54948, P = 0.0187). Conclusions: Among the pilgrims with diabetes participating in Hajj, a considerable proportion with a range of diabetic emergencies present to the onsite medical facilities. Preparation is required in terms of logistics and health education about diabetic emergencies to meet the needs of pilgrims with DM, especially those who use insulin and have longstanding diabetes. Further research on DM and the creation of guidelines for health providers and patients with DM during Hajj are important focuses for the future.
