In Vitro Performance of Different Universal Adhesive Systems on Several CAD/CAM Restorative Materials After Thermal Aging.

OBJECTIVE: To evaluate the microshear bond strength (mSBS) of 10 universal adhesive systems applied on five different CAD/CAM restorative materials, immediately and after thermal aging. METHODS AND MATERIALS: Five CAD/CAM materials were selected: 1) feldspathic glass ceramic (FeCe); 2) pre-polymerized reinforced resin composite (ReRC); 3) leucite-reinforced glass ceramic (LeGC); 4) lithium disilicate (LiDi); and 5) yttrium-stabilized zirconium dioxide (ZiDi). For each material, 15 blocks were cut into four rectangular sections (6 × 6 × 6 mm; n=60 per group) and processed as recommended by the respective manufacturer. For each indirect material, the following adhesive systems were applied according to the respective manufacturer's instructions: 1) AdheSE Universal [ADU]; 2) All-Bond Universal [ABU]; 3) Ambar Universal [AMB]; 4) Clearfil Universal Bond [CFU]; 5) Futurabond U [FBU]; 6) One Coat 7 Universal [OCU]; 7) Peak Universal Bond [PUB]; 8) Prime&Bond Elect [PBE]; 9) Scotchbond Universal Adhesive [SBU]; 10) Xeno Select [XEN, negative control]. After the application of the adhesive system, cylinder-shaped transparent matrices were filled with a dual-curing resin cement (NX3) and light cured. Specimens were tested in shear mode at 1.0 mm/min (mSBS), after 24 hours and 10,000 thermal cycles (TC). All data were submitted to statistical analysis (α=0.05). RESULTS: For FeCe, there was no significant decrease in mean mSBS for AMB, FBU, and SBU after TC when compared at 24 hours. For ReRC, AMB and SBU showed higher mean mSBS when compared to CFU and XEN, after 24 hours and TC. For LiDi, FBU and OCU showed higher mean mSBS when compared to CFU and XEN, after 24 hours and TC. For LeGC, AMB and PUB showed higher mean mSBS when compared to XEN, after 24 hours and TC. For ZiDi, OCU and SBU showed higher mean mSBS when compared to XEN, after 24 hours and TC. In addition, PBE and XEN showed the lowest mean mSBS after TC with higher percentage of bond strength reduction. CONCLUSIONS: The mean mSBS among the different universal adhesives varied widely for each CAD/CAM material used. In addition, most universal adhesives underwent a statistically significant bond strength reduction after TC.

Clinical Performance of Filled/Nanofilled Versus Nonfilled Adhesive Systems in Noncarious Cervical Lesions: A Systematic Review and Meta-analysis.

CLINICAL RELEVANCE: The use of filled adhesive systems does not influence the clinical performance of the adhesive restoration in noncarious cervical lesions.

Effects of Microabrasion Prior to In-office Bleaching on Hydrogen Peroxide Permeability, Color Change, and Enamel Morphology.

PURPOSE: This study evaluated hydrogen peroxide (HP) diffusion within the pulp chamber, as well as color change and the surface morphology of teeth subjected to various microabrasion (MA) protocols associated or not with in-office (IO) bleaching. METHODS: Forty sound premolars were randomly divided into the following four groups (n=10): no treatment (NC); IO bleaching only; IO immediately after MA (IMA), and IO seven days after MA (7MA). After treatments, the HP concentration (µg/mL) within the pulp chamber was determined using ultraviolet-visible (UV-Vis) spectrophotometry. The color change (ΔE*) was evaluated using the digital spectrophotometer before and 1 week after bleaching. The surface morphology was evaluated by scanning electron microscope (SEM). Data from each test were submitted to one-way ANOVA and Tukey tests (α=0.05). RESULTS: All experimental groups exhibited higher HP concentrations compared to the NC group (p<0.00001). However, higher amounts of HP were observed for the IMA group compared to the IO and 7MA groups (p<0.00001). No significant difference in color change was observed among the groups (p<0.001). Pronounced grooves in enamel were found in the IMA and 7MA groups. However, enamel erosion areas were observed only in the 7MA group. CONCLUSIONS: The association between MA and IO bleaching could significantly affect the amount of HP inside the pulp chamber. Therefore, it is highly recommended to wait for 1 week after MA procedures before performing IO bleaching.

Four-year Follow-up of a Direct Anatomical Fiber Post and Esthetic Procedures: A Case Report.

Knowledge about the stability of fiber posts cemented in widened canal spaces over time is scarce in the literature. Thus, the purpose of this case report was to evaluate the performance of a direct anatomical post in a widened canal space over the course of four years. The present clinical case describes the rehabilitation of a widened canal space using a direct anatomical post (a resin composite combined with a prefabricated glass fiber post) associated with an all-ceramic crown and other restorative procedures. This technique is easy to perform and may solve some of the problems associated with the cementation of a poorly adapted fiber post in a widened canal space.

Randomized Double-blind Clinical Trial of Bleaching Products in Patients Wearing Orthodontic Devices.

OBJECTIVES: This double-blind randomized clinical trial evaluated tooth sensitivity (TS) and the effectiveness (EF) of two types of bleaching agents (Trèswhite Ortho [TWO] and Trèswhite Supreme [TWS]) when used in patients wearing orthodontic appliances. METHODS AND MATERIALS: Forty patients between the ages of 18 and 40 years were randomly stratified, with an equal allocation rate, into two groups (n=20), according to the bleaching agent applied. Tooth color of the six maxillary anterior teeth was measured before and after the treatment with a spectrophotometer. The TS was recorded on three scales before and during the bleaching treatment. RESULTS: With regard to EF, a significant reduction was found (ranging from 7.3-9.6 and 5.3-9.5 Vita scale units for TWO and TWS, respectively, p<0.001); however, there was no statistical difference between the groups (p>0.63). The number of patients with sensitivity was 58.8% and 73.3% for TWO and TWS groups, respectively (p=0.53); however, with each of the three scales used, the intensity of sensitivity was low and there was no statistical difference between TWO and TWS (p>0.05). CONCLUSIONS: In spite of producing a side effect of low TS, the two bleaching treatments tested were effective for dental bleaching in patients with fixed orthodontic appliances.