Comparison of Antibacterial Activity, Cytotoxicity, and Fluoride Release of Glass Ionomer Restorative Dental Cements in Dentistry.

BACKGROUND This study aimed to compare the antibacterial activity, cytotoxicity, and fluoride release of 4 different glass ionomer cements (GIC). MATERIAL AND METHODS A total of 200 samples were prepared: Riva Silver, a silver-reinforced GIC; Equia Forte HT, a glass hybrid GIC; ChemFil Rock, a zinc-added GIC; and Ketac™ Molar Easymix. Using the agar diffusion test for antibacterial activity, 30 samples from each group were analyzed for Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces naeslundii. The areas around the samples where no bacterial growth occurred were digitally measured and recorded. For cytotoxicity analysis, the WST-1 test was performed on 10 samples from each group using the L929 mouse fibroblast cell line. The fluoride release property was evaluated using an ion-selective electrode method on 10 samples from each group. RESULTS The group that used Ketac™ Molar Easymix showed the lowest antibacterial activity against S. mutans, L. acidophilus, and A. naeslundii. In all 3 days of cytotoxicity testing, the group that used Riva Silver was found to be the least toxic material, while the group that used ChemFil Rock did not have viable cells after the 1st day. In all 4 materials, fluoride release values gradually increased since the first day, with Ketac™ Molar Easymix having the highest fluoride release. CONCLUSIONS Of all the GICs tested, Ketac™ Molar Easymix demonstrated the least antibacterial activity despite having the highest fluoride release, while Riva Silver was found to be the least cytotoxic material.

Effect of Surface Wetting Resin on the Color Stability and Microhardness of Esthetic Composites / Efecto de la resina humectante de superficies sobre la estabilidad del color y la microdureza de resinas compuestas estéticas

ABSTRACT: Objective: The aim of this study was to evaluate and compare the effects of the superficial application of two different modeling resins on the surface microhardness and discoloration of composite resins. Material and Methods: The present study used two different composites and modeling resins. The composites were placed in plastic molds. Subsequently, the modeling resins were applied on the surface of the two composite groups. The microhardness and color pertaining to all the groups were evaluated. The current study used the One-Way ANOVA and Kruskal Wallis tests, in order to perform the statistical evaluation (p<0.05). Results: The present study compared the microhardness pertaining to the groups and the highest microhardness values were observed in the Estelite Asteria group (none), whereas the lowest values were observed in the GC Essentia group (Ultradent). Moreover, the current study evaluated the color stability and the greatest discoloration was observed in the control group of the GC Essentia group, whereas the least discoloration was observed in the Estelite Asteria group that included the samples prepared using Ultradent Wetting Resin. Conclusions: The results of the present study demonstrated that the use of modeling resins, which facilitate the placement of composite resins, reduced the microhardness and discoloration of composite resins. The aforementioned effect can be attributed to the variations in the structure of the filling. However, further studies are warranted to support and verify the results of the current study.

RESUMEN: Objetivo: El objetivo del presente estudio fue evaluar y comparar los efectos de la aplicación superficial de dos resinas humectantes sobre la microdureza superficial y la decoloración de las resinas compuestas. Material y métodos: El presente estudio utilizó dos resinas humectantes y resinas de modelado diferentes. Las resinas compuestas se colocaron en moldes de plástico. Posteriormente, se aplicaron las resinas humectantes sobre la superficie de los dos grupos. Se evaluó la microdureza y el color de todos los grupos. El presente estudio utilizó las pruebas One-Way ANOVA y Kruskal Wallis, para realizar la evaluación estadística (p<0.05). Resultados: Los valores más altos de microdureza se observaron en el grupo Estelite Asteria, mientras que los menores valores se observaron en el grupo GC Essentia (Ultradent). La mayor decoloración se observó en el grupo control o el grupo GC Essentia, mientras que la menor decoloración se observó en el grupo Estelite Asteria con Ultradent Wetting Resin. Conclusiones: Los resultados del presente estudio demostraron que el uso de resinas humectantes, que facilitan la colocación de resinas compuestas, redujo la microdureza y decoloración de las resinas compuestas. El efecto mencionado anteriormente se puede atribuir a las variaciones en la estructura del relleno. Sin embargo, se necesitan más estudios para respaldar y verificar los resultados del presente estudio.

Evaluation of the use of PEEK material in post-core and crown restorations using finite element analysis.

PURPOSE: To compare the stresses generated after the use of low elastic modulus polyetheretherketone (PEEK) as dental post and crown material with glass fiber post and metal supported ceramic crowns using finite element analysis. METHODS: First an image of a maxillary central incisor taken on micro-computed tomography (micro-CT) was uploaded to a computer program. Modeling was made of all the materials in the computer environment and 3-dimensional (3D) virtual models were obtained. Using two different post materials (glass fiber and PEEK post) and two different crown materials (metal supported ceramic and PEEK crown), the modeling of the maxillary central tooth was completed and a total of four groups were obtained. Finally, 135° and 100 N forces were applied from the midpoint of the palatal surface. RESULTS: The FEA analysis showed the use of PEEK as post material decreased the stress values in the post, post cement and composite core models and did not have any significant change in the dentin and crown cement models. The use of composite veneer with PEEK substructure as crown material reduced stress values in dentin, the post and composite core and increased stress values in both the post cement and the crown cement. CLINICAL SIGNIFICANCE: Since the elastic modulus of the PEEK material is very close to dentin tissue, finite element stress analysis, less stress formation in the tooth and post core restoration compared to other post systems was observed. In this context, PEEK post may reduce irreversible complications.

Comparison of Cytotoxicity of Four Different Adhesive Materials Before and After Polymerisation.

INTRODUCTION: The aim of this study was to make a quantitative comparison of the cytotoxic potentials of four different polymerised and unpolymerised self-etching adhesives which were newly used clinically. MATERIALS AND METHODS: Cytotoxic effects of both polymerised and unpolymerised forms of all test adhesives were evaluated against L929 cell line using the MTT test. The activity for unpolymerised adhesives was assessed in different doses and incubation times manner. On the other hand, cytotoxicity of the polymerised adhesives prepared at different extraction times were evaluated as dependent on incubation times. Two-Way Variance Analysis and Bonferroni post-test was used for statistical evaluation. RESULTS: There were statistically significant differences between the groups (p < 0.05). In general, it was shown that unpolymerised and polymerised forms of each of the test compounds exhibited a time-dependent cytotoxic effect. However, the effect on polymerised forms was found to be independent of the duration of the extraction, while the effect on the unpolymerised forms increased dose-dependently. It was also determined that the most cytotoxic material in the unpolymerised form was Dentsply and in the polymerised form was Tokuyama. CONCLUSIONS: Dentsply should be preferred over Tokuyama to be able to provide clinically long-lasting restorations.

Maxillary Cortical Bone Thickness in a South-Eastern Anatolian Population: A Cone-Beam Computed Tomography Study.

BACKGROUND The aim of this study was to measure the distance between the maxillary premolar and molar teeth apices to the buccal cortical bone and evaluate differences in gender and age group, using cone beam computed tomography (CBCT). MATERIAL AND METHODS This retrospective study comprised of 451 premolar and molar teeth of one hundred and thirteen patients who were admitted to Dicle University, Faculty of Dentistry, Department of Dentomaxillofacial Radiology for different reasons. Data were analyzed using Student's t-tests and Tukey HSD tests. RESULTS There was significant difference in buccal bone thickness by gender (p<0.05). The thinnest point of the maxillary buccal bone was measured in women as 2.11 mm and in men as 2.02 mm in the first premolar teeth. The thickest point of maxillary buccal bone was measured in women as 9.87 mm and in men 10.71 mm palatinal root of the first molar. A comparison of buccal bone thickness between age showed a statistically significant difference at the distobuccal and palatinal roots of the first molar, at the mesiobuccal root of the second molar (p<0.05). CONCLUSIONS The measurements of maxillar buccal bone thickness using CBCT for various dental procedures especially in endodontic surgery, orthodontic mini implant treatment, dental implant procedures, and healing after tooth extraction that are important knowledge.