ABSTRACT
This study compared the bond strength of a composite repair made with a bulk fill composite and a conventional one using different surface treatments. Specimens were prepared as truncated cones (bases: 4 mm × 2 mm, height: 4 mm) using a bulk fill (OBFa: Filtek One) or a conventional resin (FTKa: Filtek Z250) (n = 66). They were artificially aged (10,000 cycles, 5°C-55°C, 30 sec) and subdivided according to surface treatments: NT-no treatment (control), Abr-abrasion with a diamond tip, and sand-sandblasting with aluminum oxide (50 µm). Treatments were performed over the smaller diameter surface, followed by adhesive (Scothbond Universal) application. A new specimen with similar dimensions was constructed over it using either the OBF or the FTK, totaling 12 groups (n = 11). Bond strength was assessed by tensile test. The data were submitted to two-way ANOVA separately for OBFa and FTKa, followed by Tukey's test (p < 0.05). For the aged OBFa groups, there was significant differences for composite type and surface treatment, with higher values of bond strength when repaired with the same material (OBFa/OBF > OBFa/FTK), and sandblasting and bur abrasion presented higher values compared to the control group (NT). For the aged FTKa groups, there were no differences for the composite or surface treatment. Therefore, the bulk fill resin composite tested present better repair performance when the same composite was used, while the conventional resin composite was less influenced by the material and the surface treatment performed.
ABSTRACT
BACKGROUND: The objective of this in vitro study was to evaluate the effect of the active application of self-etching ceramic primer (ME&P) on the bond strength of different dental CAD/CAM materials (Lithium Disilicate ceramic (LD), Leucite ceramic (LE), Zirconia reinforced lithium silicate ceramic (ZLS), and Hybrid ceramic (HC)) with thermocycling aging. MATERIAL AND METHODS: The samples were randomly divided into 16 groups (n = 20). Dual resin cement cylinders were made and light cured for 10 s (1.200 mW/cm2) for the shear bond strength test. 3-way ANOVA revealed that the factors were statistically significant (P< 0.05). RESULTS: The aging process had a negative impact on the bond strength for all groups except for Lithium Disilicate, with active application. ZLS and LE showed promising results with high bond strength values for the ME&P active application; however, after aging the bond strength value was significantly reduced. HC showed reduced bond strength values regardless the ME&P application. CONCLUSIONS: In order to obtain a durable bond strength, the recommended protocol of 20 s of active application followed by 40 s of sitting time in the self-etching ceramic primer should be followed when using reinforced-glass ceramics as restorative materials. Key words:Dentistry, dental materials, silane, shear strength, computer-aided design.
ABSTRACT
BACKGROUND: The present review aimed to assess the impact of being a complier to supportive periodontal therapy (SPT), when compared to not being a complier, on tooth loss in patients with periodontitis. METHODS: Prospective and retrospective observational studies were included. MEDLINE, EMBASE, and LILACS databases were searched up to May 2019. The odds-ratio (OR) and standard error (SE) values of the studied groups (compliant or non-compliant) were converted to logOR, and the results of individual studies were grouped using a random effects model. RESULTS: From a total of 1815 articles initially searched, 13 retrospective studies and one prospective study comparing tooth loss of complier and non-complier individuals in SPT were included. Meta-analysis of eight studies showed that non-compliers in SPT have an increased risk of tooth loss when compared with compliers. Overall meta-analysis demonstrated that non-compliant patients in SPT have a 26% increased risk of tooth loss when compared with compliant patients (OR = 1.26; 95% CI = 1.06 to 1.51, Heterogeneity: I2 = 0%, p = 0.008). CONCLUSIONS: Patients with periodontitis who do not comply in SPT have a higher risk of tooth loss than compliant patients. Oral health professionals should implement measures to obtain optimal adherence by patients in SPT.
Subject(s)
Tooth Loss , Follow-Up Studies , Humans , Patient Compliance , Periodontal Pocket , Prospective Studies , Retrospective Studies , Tooth Loss/etiologyABSTRACT
BACKGROUND: In this study was assessed the degree of conversion (DC) of amine-free resin cements light cured through lithium disilicate-reinforced ceramics at different thicknesses and translucency. MATERIAL AND METHODS: Specimens were divided into 21 groups (n = 5) according to luting agent used: Variolink Esthetic LC (Light shade), RelyX Ultimate (A1 shade), and Filtek Z350 XT Flow (A1 shade); the ceramic translucency: low (LT) and high (HT); and the ceramic thickness: no ceramic (control), 0.5 mm, 1 mm, and 2 mm. A Teflon mold with (5 x 5 x 0.5 mm) was used to standardize the cement and over it the ceramic block from each group was placed. Set was cured using a polywave LED light (1200 mW/cm2 - Bluephase G2) for 40 s. FTIR spectra of uncured and cured materials was obtained and DC calculated from the height of the peaks 1610 and 1640 cm-1. Data were submitted to ANOVA followed by Tukey's test (α = 0.05). RESULTS: There was a significant difference for luting agents (p< 0.0001) and translucency (p = 0.025), but not for thickness (p = 0.73). Dual amine-free RelyX Ultimate showed the lowest DC values and higher translucency promoted higher DC. CONCLUSIONS: Dual amine-free cement showed the lowest monomer conversion and higher translucency ceramics promoted a higher DC. Key words:Ceramic, degree of conversion, resin cement, thickness, translucency.