Evaluation of fracture strength and total void amount in composite restorations on endodontically treated teeth / Resistencia a la fractura y la cantidad total de burbujas en resinas compuestas de dientes tratados endodónticamente

ABSTRACT: The aim of the study was to investigate the fracture strength of different composite resins and the quantity of voids in conventional posterior composite, high- flow flowable composite, bulk-fill flowable composite, and fiber-reinforced composite. Forty-four caries-free, freshly extracted mandibular premolars were used for this study. Teeth were prepared for cavity and root canal treatment. Subsequently, root canal treatment was applied to the teeth and cavities in order to prepare them for restorations. The specimens were then divided into four groups: group-1: Estelite Posterior; group-2: Estelite Flow Quick High Flow; group-3: Estelite Bulk-fill Flow; group-4: everX Posterior. One specimen from each experimental group was examined using micro-CT to perform measurement of voids. The fracture strength values of high-flow flowable, bulk-fill flowable, fiber-reinforced, and conventional micro- hybrid composites were found to be similar (p=0.497). EverX Posterior showed the highest fracture strength values (841.1±149.4 N), followed by Estelite Bulk-fill Flow (822.8±170.8 N). Volume of voids (%) obtained from Micro-CT analysis revealed that restorations with high-flow liner or bulk-fill flowable exhibited more voids. The fiber-reinforced composite showed the lowest percentage volume of incorporating voids and the highest fracture strength results.

RESUMEN: El objetivo del estudio fue investigar la resistencia a la fractura de diferentes resinas compuestas y la cantidad de burbujas en resinas posteriores convencionales, resinas fluidas de alto flujo, resinas fluidas tipo bulk-fill y resinas reforzados con fibras. Cuarenta y cuatro premolares mandibulares libres de caries, recién extraídos, fueron usados para este estudio. Los dientes se prepararon para el tratamiento de conductos radiculares y las cavidades para prepararlos para las restauraciones. Los especímenes se dividieron en cuatro grupos: Grupo-1: Estelite Posterior; Grupo-2: Estelite Flow Quick High Flow; Grupo-3: Estelite Bulk-fill Flow; Grupo-4: everX Posterior. Un espécimen de cada grupo experimental fue examinado usando micro-CT para realizar la medición de las burbujas. Los valores de resistencia a la fractura de los compuestos de alto flujo, flujo de relleno, reforzados con fibra y microhíbridos convencionales fueron similares (p=0,497). EverX Posterior mostró los valores más altos de resistencia a la fractura (841,1±149,4 N), seguido de Estelite Bulk-fill Flow (822,8±170,8 N). El volumen de las burbujas (%) obtenido del análisis de Micro-TC reveló que las restauraciones con revestimiento de alto flujo o con flujo de relleno a granel presentaban más huecos. El compuesto reforzado con fibra mostró el menor porcentaje de volumen de incorporación de vacíos y los resultados más altos de resistencia a la fractura.

Microtensile Bond Strength Between Self-Adhesive Resin Cements and Resin Based Ceramic CAD/CAM Block / Resistencia adhesiva microtensil entre cementos de resina autoadhesivos y bloques de cerámica CAD/CAM a base de resina

Abstract: Purpose: The objective of this study is to evaluate and compare the microtensile bond strength (μTBS) of four different self-adhesive resin cements to a resin-based ceramic CAD/CAM block, at the baseline, and after subjecting them to 5,000 thermo-cycles.Materials and Methods: Four self-adhesive dual-cured resin cements; G-CEM LinkAce (GC EUROPE, Leuven, Belgium), RelyX U200 (3M ESPE, Seefeld, Germany), Maxcem Elite (Kerr, CA, USA), TheraCem (Bisco, Schaumburg, USA) were applied to Cerasmart CAD/CAM blocks (GC EUROPE, Leuven, Belgium). CAD/CAM blocks were sectioned into sticks and subjected to µTBS tests at 24 hours, and the other half were subjected to tests after 5000 thermo-cycles. The data were tested by one-way variance analysis (p<0.05). Results: The highest bond strength values were observed in TheraCem, followed by G-CEM LinkAce and RelyX U200, respectively (p<0.05). At the baseline, G-CEM LinkAce, RelyX U200, and Maxcem Elite showed statistically similar results. After 5,000 thermal-cycles, a significant decrease was observed in the bond strength values of G-CEM LinkAce (p<0.05). Conclusion: Between the adhesive cements used in the study, TheraCem showed the highest micro-tensile bond strength values both in the baseline (24h) results, and after the 5,000 thermal- cycle aging procedures.

Resumen: Propósito: Evaluar y comparar la resistencia adhesiva microtensil (μTBS) de cuatro cementos de resina autoadhesivos diferentes con un bloque CAD/CAM de cerámica a base de resina, antes y después de 5.000 ciclos de termociclado. Materiales y métodos: cuatro cementos de resina de doble curado autoadhesivos; G-CEM LinkAce (GC EUROPE, Lovaina, Bélgica), RelyX U200 (3M ESPE, Seefeld, Alemania), Maxcem Elite (Kerr, CA, EE. UU.), TheraCem (Bisco, Schaumburg, EE. UU.) fueron aplicados a bloques Cerasmart CAD/CAM (GC EUROPE, Lovaina, Bélgica). Los bloques CAD/CAM se seccionaron en barras y se sometieron a pruebas µTBS a las 24 horas, y la otra mitad se sometió a pruebas después de 5000 ciclos térmicos. Los datos fueron probados por análisis de varianza unidireccional (p<0.05). Resultados: Los valores más altos de fuerza de unión se observaron en TheraCem, seguido de G-CEM LinkAce y RelyX U200, respectivamente (p<0.05). En la línea de base, G-CEM LinkAce, RelyX U200, Maxcem Elite mostró resultados estadísticamente similares. Después de 5.000 procesos de ciclo térmico, se observó una disminución significativa en los valores de resistencia de la unión de G-CEM LinkAce (p<0.05). Conclusión: entre los cementos adhesivos utilizados en el estudio, TheraCem mostró los valores más altos de resistencia de la unión micro-extensible tanto en la línea de base (24 h) como después de 5,000 procedimientos de envejecimiento térmico.

Rhinosinusitis among the patients with perennial or seasonal allergic rhinitis.

Although no hypothesis is universally accepted, allergic rhinitis (AR) may play an important role in the occurrence of rhinosinusitis. This study was carried out to investigate the frequency and severity of rhinosinusitis among patients with seasonal or perennial AR. This study included 73 patients with AR. Findings related to rhinosinusitis of these patients were demonstrated by computed tomography (CT), and were scored according to the Lund-Mackay CT scan staging system. Fifty-two of the 73 patients (71.2%) were shown to have findings of rhinosinusitis. Of these 52, twenty-four patients (77.4%) had perennial AR and 28 (66.7%) patients had seasonal AR. The mean total CT staging score of rhinosinusitis was 4.2 +/- 3.2 in patients with perennial AR and 2.6 +/- 1.3 in patients with seasonal AR. Although the frequency of rhinosinusitis among patients with perennial AR was higher than among seasonal ones, this was statistically insignificant (p = 0.32). But CT staging scores of rhinosinusitis among the patients with perennial AR were significantly higher than among the seasonal AR group (p = 0.014). Although there was no significant difference between the frequency of rhinosinusitis of seasonal and perennial AR, the severity of rhinosinusitis was more severe in cases with perennial AR, in this study. Early management of an allergic disease is essential if its long-term consequences are to be prevented or minimized.

Serum iron, zinc and copper levels and lipid peroxidation in children with chronic giardiasis.

This study investigated the levels of iron, zinc, and copper and their demolishing effects against lipid peroxidation in chronic giardiasis. Serum iron, zinc and copper levels, erythrocyte cytosolic superoxide dismutase activity, and malondialdehyde levels were measured in 34 children with chronic giardiasis and were compared with controls. The serum iron and zinc levels and erythrocyte superoxide dismutase activity were significantly lower, and malondialdehyde levels were significantly higher among the children with chronic giardiasis compared to the control group (p < 0.001). There was no significant difference in copper levels between the two groups (p > 0.05). Consequently, the oxidant-antioxidant balance may tilt towards the oxidative side due to weakness of the antioxidant system in giardiasis. If early and proper treatment is not performed, free radical-mediated damage might occur in children with chronic giardiasis.

Diagnostic importance of serological methods and eosinophilia in tissue parasites.

This case-control study was carried out to investigate whether eosinophilia is a common finding in parasitic diseases and to determine the prevalence of the parasitic diseases in definitive groups. Toxocariasis and fasciolosis were investigated in patients with eosinophilia, patients with non-eosinophilia, and healthy controls. All cases were analyzed for antibodies against Toxocara canis and Fasciola hepatica by modified enzyme-linked immunosorbent assay (ELISA) employing, as antigen, excretory/secretory products of Toxocara and Fasciola (ES-ELISA). Seropositivity was determined in 39 (29.1%) and 12 (8.9%) toxocariasis and fasciolosis patients with eosinophilia respectively. The seropositivity was found in 26 (19.4%) and 5 (3.7%) toxocariasis and fasciolosis patients without eosinophilia respectively. The seropositivity was found in 13 (15.5%) and 1 (1.2%) toxocariasis and fasciolosis patients in the control group. The total seropositivity in both toxocariasis and fasciolosis in the eosinophilic group (8.5%) increased significantly compared to patients without eosinophilia (23.1%) and healthy controls (6.6%) (chi2:6.343, p < 0.05 and chi2:10.293, p < 0.01). Eosinophilia correlated with antibodies against Toxocara and E. hepatica. The results suggest that serological methods can be used for diagnosis of parasitic infections in tissue. Thus, the actual prevalence of tissue parasites can be revealed particularly in developing and emerging countries.