Marginal and internal adaptation is critical for the success of indirect restorations. New imaging systems make it possible to evaluate these parameters with precision and nondestructively. This study evaluated the marginal and internal adaptation of zirconia copings fabricated with two different systems using both silicone replica and microcomputed tomography (micro-CT) assessment methods. A metal master model, representing a preparation for an all-ceramic full crown, was digitally scanned and polycrystalline zirconia copings were fabricated with either Ceramill Zi (Amann-Girrbach) or inCoris Zi (Dentslpy-Sirona), n=10. For each coping, marginal and internal gaps were evaluated by silicone replica and micro-CT assessment methods. Four assessment points of each replica cross-section and micro-CT image were evaluated using imaging software: marginal gap (MG), axial wall (AW), axio-occlusal angle (AO) and mid-occlusal wall (MO). Data were statistically analyzed by factorial ANOVA and Tukey test (α=0.05). There was no statistically significant difference between the methods for MG and AW. For AO, there were significant differences between methods for Amann copings, while for Dentsply-Sirona copings similar values were observed. For MO, both methods presented statistically significant differences. A positive correlation was observed determined by the two assessment methods for MG values. In conclusion, the assessment method influenced the evaluation of marginal and internal adaptation of zirconia copings. Micro-CT showed lower marginal and internal gap values when compared to the silicone replica technique, although the difference was not always statistically significant. Marginal gap and axial wall assessment points showed the lower gap values, regardless of ceramic system and assessment method used.

Purpose The aim of the study was to measure the marginal and internal adaptation (MIA) of zirconia copings, made of 4 ceramic systems for CAD/CAM, using microcomputed tomography (micro-CT) technology. Material and Methods Two identical stainless steel models were used, representing a preparation for full ceramic crown on a lower molar. The master models were then scanned for the production of copings from specific yttrium oxide partially stabilized tetragonal zirconia polycrystal ceramic blocks of each system (n=10): Cerec/inCoris Zi, Sirona; Cercon/Cercon base, Dentsply; Ceramill/Ceramill Zi, Amann Girrbach; and Lava/Lava Frame Zirconia, 3M ESPE. MIA was evaluated measuring 4 points as follows: marginal gap (MG), axial wall gap (AW), axio-occlusal angle gap (AO), and central occlusal area gap (CO). The data were statistically analyzed by ANOVA and Tukey's test (α = 0.05). Results The ceramic system Lava showed greater internal desadaptation (80.75 ± 22.69 µm) while CEREC presented the lowest values (49.92 ± 11.77 µm). There were significant differences between the measurement points evaluated. CO demonstrated the greater values (77.03 ± 22.61 µm). All marginal and internal adaptation values were considered clinically acceptable. Conclusion It was concluded that there was an influence of the type of ceramic system in marginal and internal adaptation of copings in zirconia.

Down syndrome (DS) is a genetic disorder caused by trisomy of chromosome 21. It is the most common chromosomal abnormality found in humans. Despite the motor difficulties and biofilm accumulation, individuals with DS have low caries prevalence. In this context it is assumed that saliva plays an important role in maintaining oral health. Objective: To evaluate the following salivary components: pH, buffering capacity and salivary flow volume in children with DS aging 2-8 years-old in the city of Curitiba (PR). Material and methods: Saliva samples were collected from 20 children with DS. The following parameters were evaluated: buffering capacity, flow rate, pH, and concentrations of calcium, urea and total proteins. Results:There was a normal distribution among the variables and the values observed were not statistically significant (p > 0.05). Conclusion:The results of this study revealed that there were no statistically significant differences in salivary flow, pH, buffering capacity, urea, calcium and total proteins in the subjects studied.

Aim: To evaluate the physicomechanical properties of different hybrid composites (Charisma Diamond - CD, Aura - AU, NT Premium - NT, Opallis - OP, Filtek Z250 – Z250) after 6 months of aging in distilled water. Methods: Discs were fabricated and color measurements were performed after 24 hours and at 7, 30, and 180 days. Flexural strength was determined using the three-point bending test. For the microhardness test, the specimens were flattened to obtain polished and flat surfaces and indentations. The results for ∆E and microhardness were analyzed by two-way repeated-measures ANOVA and Tukey’s HSD test. The flexural strength results were analyzed by two-way ANOVA and Tukey’s test (α=0.05). Results: The ∆E values for composite resins varied in the following order: CD (3.54)a < Z250 (4.70)ab < AU (4.95)ab < OP (5.20)ab < NT (6.23)b. ∆E values were lower for 24 h (3.84)a < 7 days (4.43)ab < 30 days (4.93)b. The highest values were observed after 180 days (ΔE = 6.54)c. The flexural strength of composite resins varied in the following order: CD (89.17 MPa)a < Z250 (73.06 MPa)b < OP (60.30 MPa)c < NT (51.28 MPa)c < AU (23.77 MPa)d. Flexural strength values were significantly higher for 24 h (68.62 MPa)a < 180 days (51.40 MPa)b. The microhardness of composite resins varied in the following order: Z250 (112.05)a < CD (102.15)ab < OP (92.04)bc < NT (87.77)d < AU (87.68)d. Microhardness was significantly higher for 180 days (113.44)a < 24 h (78.21)b. Conclusion: The microhybrid (Z250) and one of the nanohybrid composites (CD) performed better. The color stability and flexural strength of all tested composites decreased with storage time.