RESUMEN
The aim of the study was to evaluate the effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials [CERASMART (GC); VITA ENAMIC (VITA Zahnfabrik); Lava Ultimate (3 M)] in comparison to feldspar ceramic (VITABLOCS Mark II, VITA Zahnfabrik) and resin composite materials (ceram.x universal, Dentsply Sirona). Daily brushing and acid exposure were simulated using a brushing apparatus and a solution of 0.5 vol% citric acid. Microhardness, surface roughness, and substance loss were measured at baseline and after simulation of 1 and 3 years of function. All materials showed a decrease in microhardness after 3 years and an increase in surface roughness (Ra) after 1 and 3 years. The Ra increase was statistically significantly lower for the resin-matrix ceramics than for feldspar ceramic and similar to composite material. After 3 years, only feldspar ceramic showed no significant substance loss. In conclusion, resin-matrix ceramics demonstrate reduced roughening compared to feldspar ceramics, potentially improving restoration longevity by preventing plaque buildup, but differences in abrasion resistance suggest the need for further material-specific research. Future research should aim to replicate clinical conditions closely and to transition to in vivo trials.
Asunto(s)
Cerámica , Porcelana Dental , Compuestos de Potasio , Propiedades de Superficie , Ensayo de Materiales , Resinas Compuestas , Silicatos de Aluminio , Diseño Asistido por Computadora , Materiales DentalesRESUMEN
OBJECTIVES: This study evaluated the release of bisphenol A (BPA) in wastewater after grinding of resin composites and tested three filtration materials. METHODS: Three resin composites (Ceram X, Filtek Supreme XTE and Core-X flow) were used. Samples (5mm×2mm, n=10) were prepared using a metal mold and were polymerized for 20s according to manufacturers' instructions. A dental unit was disconnected from wastewater circulation and composite samples were ground under standardized procedures (200,000rpm; 90s). Wastewater was collected in glass bottles. Water samples were collected as control by performing the same procedure without grinding resin composite. All samples were stored at 7°C for 6 months to simulate storage. Then they were analyzed by HPLC-FLD. Three filtration materials (Zeosorb, Katalox Light and Catalytic Carbon) were used for water treatment to remove BPA. BPA-water solutions were prepared; corresponding to the highest amount released by the resin composites. These solutions were analyzed before and after filtration by HPLC-FLD and their efficacy (%) was calculated. RESULTS: BPA was detected in all composite solutions: Ceram X and Filtek Supreme XTE showed similar findings (p>0.05) which were significantly higher than the control (p<0.001) and Core-X flow (p=0.001). The efficacy of the filtration materials was: Katalox Light (5.09%)Asunto(s)
Materiales Dentales
, Aguas Residuales
, Compuestos de Bencidrilo
, Resinas Compuestas
, Ensayo de Materiales
, Fenoles
RESUMEN
OBJECTIVE: The objective of this study was to evaluate the influence of delayed light curing on a dual-cured composite resin on cuspal deflection, microleakage, and enamel cracks. METHOD AND MATERIALS: Forty-eight standardized Class 2 cavities were prepared in maxillary third molars and restored with a dual-cure composite resin (Core-X Flow) in bulk-fill technique. The samples were divided into four groups (n = 12) and either self-cured (1) or light cured immediately (2), with 1 minute (3) or 2 minutes of delay (4) after placement. Cuspal deflection was measured before preparation, 6 minutes after placement, after 24 hours, and after 120 days of storage and thermocycling. The margins of the restorations were examined under a stereomicroscope after 24 hours and 120 days. Samples were immersed in a 0.2% basic fuchsin solution for 24 hours at room temperature and then sectioned vertically and mesiodistally, and dye penetration and enamel cracks were recorded under a stereomicroscope using a scoring system. RESULTS: Six minutes after placement the cuspal deflections were between 20 ± 2.1 µm and 39.3 ± 1.9 µm. After 120 days the cuspal deflection in all groups was reduced to almost complete recovery, while the percentage of perfect margin decreased. Differences in microleakage, dye penetration, and enamel cracks were observed between different locations but not between the groups. Statistical analysis did not show a correlation between cuspal deflection, margin quality, or enamel cracks. CONCLUSION: A short delay in light curing of a dual-cure composite resin could significantly reduce the initial cuspal deflection measured 6 minutes after light curing, thereby probably reducing the polymerization shrinkage stress. However, the curing mode did not significantly influence microleakage and enamel cracks.
Asunto(s)
Resinas Compuestas/química , Filtración Dental , Restauración Dental Permanente/métodos , Recubrimientos Dentinarios/química , Curación por Luz de Adhesivos Dentales , Fracaso de la Restauración Dental , Humanos , Técnicas In Vitro , Ensayo de Materiales , Tercer Molar , Propiedades de Superficie , Factores de TiempoRESUMEN
The aim of this in vitro study was to evaluate the long-term effect of bleaching on human enamel. Four groups of enamel specimens were prepared (n = 20): group 1: bleaching with Opalescence Boost [40% hydrogen peroxide (H2O2), 3 × 20 min/week]; group 2: control group (the specimens were stored in human saliva); group 3: beaching with Vivastyle Paint on Plus (6% H2O2, 2 × 10 min/day), and group 4: bleaching with Opalescence PF 16% [16% carbamide peroxide (CP), 6 h/day]. After each bleaching session the specimens were stored in human saliva. Knoop microhardness and surface roughness were measured: before bleaching, after 2-week and after 8-week bleaching. After 2-week treatment, surface roughness was significantly increased in all experimental groups (p < 0.05), while among them no significant difference was found (p > 0.05). The roughness changes exerted after 8-week bleaching were not significantly higher than the ones after 2 weeks (p > 0.05). After 8-week treatment, the increase in roughness caused by 16% CP was significantly higher (p < 0.05) than the one caused by 40% H2O2. Microhardness increased in all groups including control; however, only 40% H2O2 increased the microhardness significantly (p < 0.05). The effect of bleaching on enamel was not shown to be dependent on the method or the H2O2 concentration. Bleaching with CP 16% resulted in higher roughness than bleaching with H2O2, while 40% H2O2 caused the higher microhardness increase. The present study showed that in-office bleaching with 40% H2O2 seems to be at least as safe as home bleaching as far as their effects on human enamel are concerned.