This study aimed to examine the effects of different light-curing modes on the immediate shear bond strength (SBS) of different composite resin types to dentin using universal adhesive. Human teeth were extracted and sectioned to obtain flat dentin slices. The universal adhesive was applied in total-etch mode. Conventional and bulkfill composites were used to create cylindric build-ups. Full power and Ramp mode were used to light-cure the adhesive and composite resin. SBS test was performed in a universal testing machine, and failure modes were determined via scanning electron microscopy (SEM). Two-way ANOVA and Student t-test were used to analyze statistical data. Significantly higher SBS was obtained when bulkfill composite was used compared to the conventional one ( p < .001). The difference between Full power and Ramp curing mode was insignificant ( p = .4). Mixed failure was the predominant type. Low SBS resulted in adhesive failure, while high SBS resulted in cohesive failure. Shear bond strength was not curing-dependent but rather material-dependent. Ramped curing does not contribute to higher bond strength. Bulkfill composite seems to be more favourable in terms of bond strength.

The recent spread of COVID-19 presents a huge public health concern. Clinical presentations of COVID-19 range from asymptomatic cases to severe pneumonia that can lead to death. Drastic measures were necessary to prevent the disease from spreading and protect the most vulnerable groups in the general population. The rapid reorganization of the healthcare system and great efforts made by medical staff were needed to admit to hospitals and then treat a progressively growing number of patients. The predominant route of virus transmission is through direct contact with an infected individual or respiratory droplets, therefore, all dental procedures with aerosol-formation pose an extremely high risk for the spread of infection. The aim of this article is to provide an overview of the current epidemiological situation, routes of transmission, and specific recommendations for dental practices including patient screening and triage, infection control, and treatment protocols. In this situation, it is essential that all dental healthcare workers make wise clinical decisions and educate themselves and their patients on how to prevent the spread of infection.

Background/Objectives: Facial and intraoral parameters are important guidelines in prosthetic planning and rehabilitation. This study aimed to analyze and determine the relationship between facial parameters and measurements on the upper anterior teeth using digital photography of the participants. Methods: This cross-sectional observational study included 82 student participants. Digital images (front facial and dental view) were taken of each participant, and then standardized images were used to measure facial and dental parameters. Results: The width of the maxillary anterior teeth and facial parameters were greater in males than in females, except for the medial canthus of the eye, which was slightly larger in females. A significant positive correlation was found between all facial parameters and the widths of the central and lateral incisors, as well as their combined sum. The strongest correlation was observed between the lateral canthus of the eye and the total width of the maxillary anterior teeth (r = 0.546; p < 0.001). In regression analysis, it was shown that the bizygomatic width had a statistically significant contribution to the prediction of the central incisor width (p = 0.045). It was also shown that the intraoral parameters, such as the height of the interdental papilla and interpapillary angle, are shape-dependent. Interincisal angles between the central incisors in all participants are significantly lower (p < 0.05) than the angles between incisal edges in other anterior teeth. Conclusions: Facial parameters cannot be used independently to predict dental parameters; nevertheless, when integrated with basic esthetic principles, they provide complementary information relevant to analytical procedures in restorative and prosthetic dentistry.

Sodium hypochlorite (NaOCl), as the most commonly used irrigant solution, offers strong antibacterial and organic tissue dissolving properties and has the potential to express a strong corrosive effect. The aim of the study was to evaluate the effects of NaOCl on corrosion behavior and cyclic fatigue in five different types of NiTi rotary endodontic instruments. The study examined: ProTaper Universal, ProTaper Next, Twisted File, HyFlex CM, and BioRace, each with 24 samples. Each group was divided into a control subgroup and a subgroup exposed to electrochemical testing of corrosion in 5.25% NaOCl. All instruments were exposed to a cyclic fatigue test in artificial canals with a curvature angle of 60 degrees and radius of 2 mm. The corrosion potential of NaOCl was determined in all groups of instruments. ProTaper Universal had a significantly lower corrosion resistance than ProTaper Next (p < 0.05), Twisted File, BioRace, and HyFlex CM (p < 0.001). HyFlex CM showed significantly higher resistance to cyclic fatigue compared to all the other groups of instruments (p < 0.001). Surface corrosion reduced cyclic fatigue resistance in most of the instrument groups, except in heat-treated instruments with controlled memory. HyFlex CM has proven to have the highest resistance to corrosion and cyclic fatigue.

The length of tooth enamel conditioning time and the size of bracket bases are some the factors influencing the bond strength between the two adherents. The aim of this study was to compare the shear bond strength (SBS) between two different types of bonded metal brackets and acid-etched enamel surface in two different times. Forty extracted human premolars were randomly divided into four groups. In groups 1 and 2, metal brackets Topic (Dentaurum, Germany) were bonded after etching with 37% phosphoric acid (Gel, Reliance, USA) for 15 s and 30 s, while in groups 3 and 4, metal brackets Equilibrium mini (Dentaurum, Germany) were bonded after etching for 15 s and 30 s. Brackets were bonded using flowable composite Heliosit Orthodontic (Ivoclar Vivadent, Liechtenstein) and light-cured using a LED lamp. The SBS was measured by an electronic dynamometer at a cross-head speed of 5 mm/min. Statistical analysis revealed that SBS is affected by both bracket type (t = 10.62; p < 0.01) and etching time (t = 2.81; p = 0.008). The Equilibrium mini brackets with previous enamel etching for 30 s showed the highest SBS values of 10.8 ± 0.75 MPa, while the Topic brackets with previous enamel etching for 15 s showed the lowest values of 4.85 ± 0.53 MPa. Increasing the etching time of tooth enamel leads to higher values in bond strength, especially when using a bracket with a smaller base.