Minimally invasive cerebral revascularization in moyamoya disease in adult patients.

BACKGROUND: Moyamoya disease (MMD) affects young patients, is generally progressive, and results in strokes or cerebral hemorrhages for which medical management is not effective. OBJECTIVE: To determine the effectiveness of surgical management with minimally invasive cerebral revascularization in MMD. MATERIAL AND METHODS: We conducted a retrospective cohort study of patients undergoing extracranial-intracranial microsurgical revascularization surgery with mini-craniotomy, analyzing the epidemiological, clinical, neuroimaging, postoperative evolution, and complications. We describe the technique in detail. Key outcomes included graft patency, complications, and recurrence of ischemic or hemorrhagic stroke. RESULTS: From September 2017 to December 2020, 12 brain revascularization procedures for MMD were performed in eight patients (four bilateral), and all 12 grafts were classified as patent. The main complication was contralateral cerebral infarction identified by postoperative neuroimaging in a patient without clinical symptomatology. There was no case of scalp ischemia or necrosis when performing the minimally invasive approach with linear incision. CONCLUSIONS: The results of this study suggest that the minimally invasive extracranial-intracranial cerebral revascularization procedure for MMD in adults is effective, with graft patency in all cases and minimal morbidity.

Flexural strength of glass and polyethylene fiber combined with three different composites.

STATEMENT OF PROBLEM: The flexure of the fiber- reinforced composites (FRC) which can be generally used instead of fixed metal- framework prostheses have been more advocated due to the enormous demands for the conservative and esthetic restoration. The flexure of the fiber should be well-fitted to its covering composite. No study has been reported the comparison of the combination of glass and polyethylene fiber with particulate filled composite and fiber reinforced composite yet. PURPOSE: This study compared the flexural strength of two types of fibers combined with three types of composites. MATERIALS AND METHOD: Sixty-six specimens were prepared in a split mold (25×2×2 mm). The specimens were divided into six groups according to the type of resin and the fiber (N = 11): group 1: Z250 composite + Polyethylene fiber; group 2: Build It composite + Polyethylene fiber; group 3: Nulite F composite+ Polyethylene fiber; group 4: glass fiber + Z250 composite; group 5: glass fiber + Build-It composite and group 6: glass fiber + Nulite F. The mean flexural strengths (MPa) values were determined in a 3-point bending test at a crosshead speed of 1 mm/min by a universal testing machine (Zwick/Roell Z020, Germany). The results were statistically analyzed, using one and two- way ANOVA and LSD post-hoc tests (p< 0.05). RESULTS: The highest flexural strength was registered for glass fiber in combination with Z250 composite (500 MPa) and the lowest for polyethylene fiber in combination with Build-It composite (188 MPa). One-way ANOVA test revealed that there was no statistically significant difference between polyethylene fiber combinations (p= 0.62) but there was a significant difference between glass fiber combinations (p= 0.0001). Two-way ANOVA revealed that the fiber type had a significant effect on flexural strength (p= 0.0001). CONCLUSION: The choice of fiber and composite type was shown to have a significant positive influence on the flexural properties of the fiber-reinforced composite. Glass fiber has a significant influence on the flexural properties of directly- made specimens.

Microleakage of Posterior Composite Restorations with Fiber Inserts Using two Adhesives after ging.

STATEMENT OF PROBLEM: Microleakage is one of the most frequent problems associated with resin composites, especially at the gingival margin of posterior restorations. Insertion of fibers in composite restorations can reduce the total amount of composite and help to decrease the shrinkage. PURPOSE: The aim of this study was to evaluate the effect of polyethylene fiber inserts on gingival microleakage of class II composite restorations using two different adhesive systems. MATERIALS AND METHOD: In this experimental study, class II cavities were prepared on 60 premolars. The gingival floor was located 1.0 mm below the CEJ. Dimension of each cavity were 3 mm buccolingually and 1.5 mm in axial depth. The specimens were divided into 4 groups according to the adhesive type and fiber insert (n=4). Single bond and Clearfill SE bond and Filtek p60 were used to restore the cavities. In groups without fiber inserts composite was adapted onto cavities using layering technique. For cavities with fiber inserts, 3 mm piece of fiber insert was placed onto the composite increment and cured. The specimens were stored in distilled water at 37(o)C for 6 months. All specimens were subjected to 3000 thermo-cycling. The tooth surfaces except for 1 mm around the restoration margins covered with two layers of nail varnish .The teeth were immersed in 2% Basic Fuchsin for 24 hours, then rinsed and sectioned mesiodistally. The microleakage was determined under a stereomicroscope (40X). Data were statistically analyzed by Kruskal-wallis and Mann-Whitney U tests (p< 0.05). RESULTS: The Kruskal-Wallis test revealed no significant differences in mean microleakage scores among all groups (p= 0.281). CONCLUSION: Use of polyethylene fiber inserts and etch-and-rinse and self-etch adhesives had no effect on microleakage in class II resin composite restorations with gingival margins below the CEJ after 6- month water storage.

Effects of 35% carbamide peroxide gel on surface roughness and hardness of composite resins.

OBJECTIVE: Bleaching agents may not be safe for dental materials. The purpose of this in-vitro study was to evaluate the effects of Opalescent Quick "in-office bleaching gel" containing 35% carbamide peroxide on the surface roughness and hardness of microfilled (Heliomolar) and hybride (Spectrum TPH) composite resins. MATERIALS AND METHODS: Twenty specimens of Spectrum TPH composite resins and twenty Heliomolar composite resins were fabricated using a metallic ring (6.5 mm diameter and 2.5 mm thickness) and light cured, then their surfaces were polished. Specimens of each composite resin were divided into two equal groups. Ten specimens of each type of composite were stored in water at 37°C as the control groups and 35% carbamide peroxide gel (Opalescence Quick) as the other group for 30 minutes a week for 3 weeks. Then the specimens were subject to roughness and hardness tests. RESULTS: This study revealed that using 35% carbamide peroxide bleaching gels had no significant effect on the surface roughness of Spectrum TPH "hybrid" and Heliomolar "microfilled" composite resins. The surface hardness of Spectrum TPH composite treated with the subject gel significantly increased compared to heliomolar, which had no significant change after treatment with this bleaching gel. CONCLUSION: If tooth color matching of the composite had been satisfactory after office bleaching with 35% carbamide peroxide gel, this material would have been acceptable because it has no adverse effect on Heliomolar and Spectrum TPH composite resins.