ABSTRACT
Objective: Compare the surface roughness of two composite resins after immersion in carbonated beverages. Materials and methods: 160 resin discs (6 x 2 mm) were divided into 8 groups (n=20 per group) according to type of resin (Filtek™ Z350 XT® and Palfique LX5®) and type of immersion in beverages (distilled water, Coca Cola®, Inca Kola® and Kola Escocesa®. The immersions were carried out under a structured cycle: 4 immersions a day for 5 days, intermediate storage in distilled water and overnight incubation for 8 h at 37°C. The measurements with the roughness meter were evaluated in three times: baseline, 7 and 14 days. The three-way Anova test was used at P<0.05. Results: Roughness showed differences only for the individual factors of time (P<0.000) and resin (P=0.000), and for the interaction time*drink (P=0.000) and resin*drink (P=0.003). Roughness was higher with Filtek Z350 XT® immersed with Inca Kola® (0.85 ± 0.37) than 14 days compared to other times (P=0.035) and with Palfique LX5 immersed in Coca Cola® at 7 days (1.61 ± 0.42) and in Inca Kola® at 14 days (1.66 ± 0.56) compared to distilled water (P<0,05). Conclusion: Surface roughness was affected by the type of resin, the type of soft drink and the immersion time. The roughness was greater with the Palfique LX5® nanohybrid resin, the Inca Kola® drink and after 14 days of immersion.
ABSTRACT
Introduction: In oral rehabilitation, the use of ceramic restorations is widely accepted due to its aesthetic capacity to mimic the naturalness of the dental tissue, provide longevity of the material, and present a greater marginal fit compared to crowns with a metal structure. Termination lines are biological preparations whose function is to minimize the cervical opening of the marginal seal. Consequently, analyzing the behavior of restorative materials under compressive forces decreases the risk of fracture and increases the success of the treatment. Objective: To compare the compressive stresses of lithium disilicate crowns with three different finishing lines. Methodology: In silico study of the simulation of a dental preparation on a lower right first molar with chamfer (0.6 mm), shoulder (0.5 mm) and deep chamfer (0.5 mm) finish lines. Using the SolidWorks®ï¸ version 2017 software, the maximum stresses, minimum stresses, and location of the compressive force were collected on the Megapascal (Mpa) measurement scale. Results: The chamfer type termination line (0.6mm) obtained a lower compressive stress compared to the other two shoulder type termination lines (0.5mm) and deep chamfer (0.5mm). Conclusions: It was shown that the chamfer type finishing line (0.6mm) presented a better force distribution, determining greater reliability in the selection of this finishing line with the use of a lithium disilicate crown in a unitary manner.
ABSTRACT
Introduction: The dentist and auxiliary personnel are in constant risk of occupational diseases such as: allergies, infections, skin or eye injuries; that could affect patients. A problem of social interest are the ocular injuries that occur to dental personnel. The literature reveals the prevalence of eye injuries in dental practice that are associated with solid particles, fluid splashes. Our objective was, through a systematic review, to review the types of ocular injuries and their associated factors that occurred in dental practice. Material and Methods: The relevant studies were searched in the databases: PubMed, Scopus, Ebsco, among others. The search included cross-sectional studies that evaluated the evidence on ocular injuries occurring in dental practice, excluding literature reviews, letters to the reader, and editorials. Results: Eight studies were included to develop the systematic review; determining that the associated factors of ocular injuries occurred in dental practice are: a) occasional use of ocular protection b) age c) sex d) years of practice and the types of ocular injuries are the entry of liquids and foreign bodies. Conclusions: Deficiency in compliance with eye or facial protection protocols in dental practice, cause eye injuries; Type of fluid entry, foreign bodies, splash of biological fluids or conjunctivitis. These eye injuries are generated from associated factors such as the occasional use of eye protection, age, sex, and others.