Micro-shear bond strength of a novel resin-modified glass ionomer luting cement (eRMGIC) functionalized with organophosphorus monomer to different dental substrates.

Objectives: This study aims to assess and compare the micro-shear bond strength (µSBS) of a novel resin-modified glass-ionomer luting cement functionalized with a methacrylate co-monomer containing a phosphoric acid group, 30 wt% 2-(methacryloxy) ethyl phosphate (2-MEP), with different substrates (dentin, enamel, zirconia, and base metal alloy). This assessment is conducted in comparison with conventional resin-modified glass ionomer cement and self-adhesive resin cement. Materials and methods: In this in vitro study, ninety-six specimens were prepared and categorized into four groups: enamel (A), dentin (B), zirconia (C), and base metal alloys (D). Enamel (E) and dentin (D) specimens were obtained from 30 human maxillary first premolars extracted during orthodontic treatment. For zirconia and metal alloys, 48 disks were manufactured using IPS e.max ZirCAD through dry milling and Co-Cr powder alloy by selective laser milling. Each group was further subdivided into three subgroups (n = 8) according to the luting cement used: (1) Fuji PLUS resin-modified glass ionomer luting cement (FP) as a control cement, (2) modified control cement (eRMGIC), and (3) RelyX U 200 (RU 200) self-adhesive resin cement. The two-way analysis of variance and Tukey's HSD were used to assess the data obtained from measuring the µSBS of the samples. Results: The results of this study showed that the mean µSBS values of eRMGIC were statistically higher compared to FP in all tested groups (p < 0.001). The mean µSBS results of eRMGIC were non-significantly different from those recorded by RU 200 for all substrates except for the dentin substrate, where the RU200 cement produced significantly higher strength (p < 0.001). The failure modes were limited to a combination of mixed and adhesive failures without pure cohesive failure. Significance: The functionalization of FP with an organophosphorus co-monomer (2-MEP) directly affects the adhesion performance of the functionalized cement, which may be utilized to develop a new type of acid-base cement. It exhibited a performance comparable to that of resin-based cement and should serve well under different clinical conditions.

Using Functionalized Micron-Sized Glass Fibres for the Synergistic Effect of Glass Ionomer on Luting Material.

This laboratory experiment was conducted with the objective of augmenting the mechanical properties of glass ionomer cement (GIC) via altering the composition of GIC luting powder through the introduction of micron-sized silanized glass fibres (GFs). Experimental GICs were prepared through the addition of two concentrations of GFs (0.5% and 1.0% by weight) to the powder of commercially available GIC luting materials. The effect of GF in set GIC was internally evaluated using micro-CT while the mechanical attributes such as nano hardness (nH), elastic modulus (EM), compressive strength (CS), and diametral tensile strength (DTS) were gauged. Additionally, the physical properties such as water solubility and sorption, contact angle (CA), and film thickness were evaluated. Reinforced Ketac Cem Radiopaque (KCR) GIC with 0.5 wt.% GF achieved improved nH, EM, CS, and DTS without affecting the film thickness, CA or internal porosity of the set GIC cement. In contrast, both GF-GIC formulations of Medicem (MC) GIC showed the detrimental effect of the GF incorporation. Reinforcing KCR GIC with 0.5 wt.% silanized GFs could improve the physical and mechanical attributes of luting material. Silanized GF, with optimal concentration within the GIC powder, can be used as a functional additive in KCR GIC with promising results.

Reparación de fractura aislada del mango del martillo con cemento ionomérico vidrioso autocurado / Repair of a malleus handle fracture using glass ionomer luting cement

Resumen La fractura aislada del mango del martillo es una entidad clínica poco habitual, pero frecuentemente subdiagnosticada. Lo fundamental es la sospecha clínica. El diagnóstico se confirma con la otoscopia neumática o la otomicroscopia con maniobra de Valsalva, en la cual se observa una movilidad anormal del mango del martillo. El rasgo de fractura se puede demostrar con tomografía computada de alta resolución o cone beam. Existen diferentes opciones de tratamiento como interposición de cartílago o uso de prótesis de reemplazo osicular así como cemento óseo. El cemento ionomérico vidrioso autocurado, muy utilizado en odontología, se ha usado en distintas cirugías otológicas con buenos resultados y biocompatibilidad. A nuestro saber no se ha usado en esta patología por lo que presentamos esta serie de tres casos en los cuales se ha usado esta novedosa técnica con buenos resultados clínicos.

Abstract Isolated fracture of the manubrium of the malleus is a rare clinical entity. Clinical suspicion is paramount. The usual clinical presentation is acute otalgia followed by tinnitus and fluctuating hearing loss after a brisk introduction and withdrawal of a finger into the external auditory canal. On physical examination, the eardrum looks normal on otoscopy. Only in pneumatic otoscopy or otomicroscopy with Valsalva an abnormal motility of the manubrium could bee seen. High-resolution computed tomography (CT) or cone beam CT is able to show the fracture line. Several treatment options have been proposed, such as interposition of bone or cartilage between the manubrium and the incus, total or partial ossicular replacement prosthesis; and the use of bone cement. Glass ionomer luting cement, with wide use in dentistry, has been used in several otological procedures with good biocompatibility and results, however, to our best knowledge, it has not been used to repair this type of fractures, so we present this novel material in three cases.

Water interaction with dental luting cements by means of sorption and solubility / Interação da água com cimentos dentais de acordo com a sorção e solubilidade

Water contributes to the setting reaction of self-adhesive luting cements, however, it can also accelerate their degradation. Objectives: The aim of this study was to compare a self-adhesive resin luting cement to other resin-based and glass-ionomer luting materials with regards to water sorption (WS) and solubility (WSB). The tested null hypothesis was that there is no difference in respect to these properties among the materials. Material and methods: Eight specimens from each group (15 mm x 0.5 mm) were prepared from self-adhesive luting cements Biscem (BC) and RelyX Unicem (R), dual-cure cements Bifix (BF), Allcem (A) and Enforce (E), chemical-cure cements C&B (CB) and Cement Post (CP) and a glass-ionomer luting cement Meron C (M) as the control group. The dual-cure products were light-cured beneath an IPS Empress Esthetic ceramic disk (20 mm x 1.5 mm) and for the chemical reaction materials, a 15 min-interval was respected for removal from the mould. The WS and WSB were respectively calculated as (m2-m3/V) and (m1-m3/V). Mass values of m1, m2 and m3 were determined by cycles of desiccation, water-immersion and a new desiccation. For each property, the data was analyzed by one-criteria ANOVA and Tukey tests (p < 0.05). Results: The glass-ionomer cement presented the highest WS, followed by the self-adhesive luting cements. Other resin cements were less susceptible to WS. No materials differed from each other when the WSB was considered, except for the M, which presented the lowest WSB. Conclusions: Self-adhesive luting cements were more prone to WS since water is essential to their setting reaction. However, their WSB was similar to the other resin-based cements.

A água contribui para a reação de presa dos cimentos auto adesivos, entretanto pode acelerar a sua degradação. Objetivos: O objetivo deste estudo foi comparar cimentos auto adesivos a outros cimentos resinosos e material ionomérico em relação à sorção de água (WS) e solubilidade (WSB). A hipótese nula foi de que não há diferença em relação a essas propriedades entre os materiais. Material e métodos: Oito espécimes de cada grupo (15 mm x 0,5 mm) foram preparados dos cimentos auto adesivos Biscem (BC) e RelyX Unicem (R), cimentos duais Bifix (BF), Allcem (A) e Enforce (E), cimentos químicos C&B (CB) e Cement Post (CP) e um cimento ionomérico Meron C (M) como grupo controle. Os produtos duais foram fotoativados sob um disco cerâmico de IPS Empress Esthetic (20 mm x 1,5 mm) e para os materiais de reação química, um intervalo de 15 min foi respeitado para a remoção do molde. A WS e WSB foram respectivamente calculadas como (m2-m3/V) e (m1-m3/V). Valores de massa m1, m2 and m3 foram determinadas pelos ciclos de dessecação, imersão em água e nova dessecação. Para cada propriedade, os dados foram analisados pelos testes de ANOVA a um critério e Tukey (p < 0.05). Resultados: O cimento ionomérico apresentou a maior WS, seguido dos cimentos auto adesivos. Os demais cimentos resinosos foram menos suscetíveis a WS. Nenhum material diferiu do outro quanto a WSB foi considerada, exceto por M, que apresentou a menor WSB. Conclusões: Cimentos auto adesivos foram mais suscetíveis a WS, uma vez que a água é essencial para sua reação de presa. Entretanto, seu WSB foi similar aos demais cimentos resinosos.