Color stability and surface roughness of artificial teeth brushed with an experimental Ricinus communis toothpaste

Aim: To evaluate, in vitro, the effect of brushing with a Ricinus communis -based experimental toothpaste on color stability and surface roughness of artificial teeth. Methods: Ninety artificial teeth (maxillary central incisors) in different shades, light and dark (NatusDent Triple Pressing, Dentbras) were used. Initial color (Spectrophotometer Easyshade, VITA) and surface roughness (Rugosimeter Surfcorder SE 1700, Kosakalab) readouts were performed. After baseline measurements, samples were assigned to 10 groups (n=9) according to the artificial tooth shade and type of toothpaste used during the mechanical brushing test (Pepsodent, MAVTEC): Sorriso Dentes Brancos – SDB, Colgate Luminous White - CLW (Colgate-Palmolive), Close up White Now - CWN (Unilever), Trihydral - THL (Perland Pharmacos) and Ricinus communis - RCE (Experimental). After 29,200 cycles of brushing, corresponding to 2 years of brushing by a healthy individual, new color and roughness readouts of the specimens were performed. Data (before and after the tests) were statistically analyzed (2-way repeated measures ANOVA, Tukey, p<0.05). Results: RCE toothpaste produced the greatest color stability for dark tooth shade and the second best color stability for light tooth shade. For surface roughness alteration, there was no difference (p>0.05) for any tested toothpaste regardless of tooth shade. Conclusions: The experimental Ricinus communis toothpaste did not cause color and surface roughness alteration in the artificial teeth, and it may be considered a suitable option for denture cleaning.

Influence of shade, curing mode, and aging on the color stability of resin cements

The color stability of resin cements is essential for aesthetic restorations. Aim: To evaluate the influence of shade and aging time on the color stability of two light-cured and two dual-cured resin cements. Methods: The CIE-Lab color parameters (n=6) were measured immediately after sample preparation and at 7, 30 and 90 days of aging in distilled water. The color difference (ΔE) was calculated and then analyzed by three-way ANOVA for repeated measures and Tukey’s HSD test (α=0.05). Results: ΔE was higher for transparent resin colors, followed by dark and light colors. The mean values of ΔE were lower for both light-cured resin cements compared to the dual-cured cements. As the aging time increased, ΔE values increased. Conclusions: The light-cured resin cements showed greater color stability. The lighter shades of luting were more likely to display a greater color change.

Salivary cortisol level and uncooperative behavior in pediatric dental practice

Aim: To investigate the relation between uncooperative behavior and salivary cortisol level in children who underwent preventive dental care. Methods: The sample was composed by 10 children of both sexes aged 40 to 52 months, presenting uncooperative behavior during dental preventive treatments. The saliva collection was performed using a cotton wheel and an Eppendorf tube (Sarstedt Salivete®) in 3 different moments: a) at home, on a day without dental treatment and at the same time on the day of the sessions treatment; b) 30 min after the end of the session, when there was manifestation of uncooperative behavior; c) 30 min after the end of the session, when there was a cooperative behavior of the child. A sample of saliva was centrifuged for 5 minutes at 2400 rpm, 1 of mL of saliva was pipetted in an Eppendorf tube and stored in a freezer at -20 ° C. For the determination of the levels of salivary cortisol was used an Active® kit for cortisol enzyme immunoassay (EIA) DSL-10-67100, composed of specific rabbit antibody anti-cortisol. Data were analyzed statistically for the uncooperative behavior issued in the beginning and at the end of sessions, using the paired t test (p<0.05) and for cortisol levels in saliva samples at home, after the beginning and at the end of sessions, using repeated-measures ANOVA and Tukey’s test (p<0.05). Results: During expression of uncooperative behavior in preventive dental care sessions the salivary cortisol level was significantly higher (0.65 ± 0.25 μg/dL) compared with expression of collaborative behavior (0.24 ± 0.10 μg/dL). Conclusions: It is possible to conclude that, even under preventive intervention, the stress must be controlled in order to reduce dental anxiety and fear.