Objective This survey aimed to assess the effects of coronavirus disease 2019 (COVID-19) on elective and urgency/emergency dental care and dentists concerned. Materials and Methods A web-based survey was performed using Google forms questionnaire sent to dentists in Brazil. Questions included: personal information, type of dental care provided during quarantine, if emergencies increased, the dental office biosafety routine, among others. The levels of concern about the impact of quarantine on dental care and patient oral health conditions and the economic impact on dental practices were evaluated using a 0- to 10-point scale. Statistical analysis included descriptive, percentages, one-way ANOVA, Tukey, and chi-square tests. Results During quarantine, 64.6% of the dentists attended only urgency/emergency treatments, while 26.1% maintained routine appointments, and 9.3% closed the dental offices. A higher percentage of dentists from the least affected states continued routine dental treatment; dentists were younger and presented a significantly lower level of concern about dental treatments and oral health conditions of their patients. An increase in urgency/emergency procedures was reported by 44.1% of the dentists, mostly due to the unavailability of routine/elective dental care and increased patient anxiety and stress. The main causes of urgency/emergency appointments were toothache, dental trauma, and broken restorations, besides the breakage of orthodontic appliances and temporomandibular disorders. Dentists reported a high level of concern about the economic impact caused by quarantine. Conclusions The pandemic/quarantine has negatively affected the clinical routine. Personal protection/hygiene care must be adopted and reinforced by dental professionals/staff to make dental procedures safer.

The aim of this study was to evaluate the influence of different concentrations of hydrofluoric acid (HF) associated with varied etching times on the microshear bond strength (μSBS) of a resin cement to a lithium disilicate glass ceramic. Two hundred seventy-five ceramic blocks (IPS e.max Press [EMX], Ivoclar Vivadent), measuring 8 mm × 3 mm thickness, were randomly distributed into five groups according to the HF concentrations (n=50): 1%, 2.5%, 5%, 7.5%, and 10%. Further random distribution into subgroups was performed according to the following etching times (n=10): 20, 40, 60, 120, and 20 + 20 seconds. After etching, all blocks were treated with a silane coupling agent followed by a thin layer of an unfilled resin. Three resin cement cylinders (∅=1 mm) were made on each EMX surface, which was then stored in deionized water at 37°C for 24 hours before testing. The μSBS was in a universal testing machine at a crosshead speed of 1 mm/min until failure. Data were submitted to two-way analysis of variance, and multiple comparisons were performed using the Tukey post hoc test (α=0.05). One representative EMX sample was etched according to the description of each subgroup and evaluated using scanning electron microscopy for surface characterization. The HF concentrations of 5%, 7.5%, and 10% provided significantly higher μSBS values than 1% and 2.5% (p<0.05), regardless of the etching times. For 1% and 2.5% HF, the etching times from 40 to 120 seconds increased the μSBS values compared with 20 seconds (p<0.05), but etching periods did not differ within the 5%, 7.5%, and 10% HF groups (p>0.05). The effect of re-etching was more evident for 1% and 2.5% HF (p<0.05). Different HF concentrations/etching times directly influenced the bond strength and surface morphology of EMX.

SUMMARY Direct composite resin veneers are a practical esthetic restorative treatment for reestablishing the shape and color of affected anterior teeth. The present clinical case reports aim to describe restorative treatment techniques for nonvital anterior teeth presenting color alteration. The direct composite resin layering technique has proven to be an efficient method for recovering the esthetics of darkened teeth. The direct vs indirect restorative treatments are debated as well. Clinical follow-ups of the presented case reports demonstrate that direct composite resin restorations are not affected by the darkened tooth substrate over time.

This study investigated the influence of different hydrofluoric acid (HF) concentrations and heat treatments applied to a lithium disilicate dental glass-ceramic (EMX) on surface morphology and micro-shear bond strength (μSBS) to resin cement. Five HF concentrations (1%, 2.5%, 5%, 7.5% and 10%) and four different heat treatments applied before etching were assessed: 1. etching at room temperature with no previous heat treatment (control group); 2. HF stored at 70°C for 1 min applied to the ceramic surface at room temperature; 3. HF at room temperature applied after a hot air stream is applied perpendicularly to the ceramic surface for 1 min; 4. the combination of previously heated HF and heated EMX surface. The etching time was fixed for 20 s for all groups. Etched EMX specimens were analyzed on field-emission scanning electron microscope (FE-SEM) and the μSBS was carried out on a universal testing machine at a crosshead speed of 1 mm/min until fracture. For the control groups, FE-SEM images showed greater glassy matrix dissolution and higher μSBS for 7.5% and 10% HF concentrations. The previous heat treatments enhanced the glassy matrix dissolution more evidently for 1%, 2.5% and 5% and yielded increased μSBS values, which were not statistically different for 7.5% and 10% HF concentrations (control group). HF concentrations and previous heat treatments did show to have an influence on the etching/ bonding characteristics to lithium disilicate dental glass-ceramic.