Aims/Objectives:To evaluate the effect of glass and polyethylene fiber inserts and flowable composite as a liner on the microleakage of Class II composite restorations with gingival margins on root surfaces.Materials and Methods:Class II slots were prepared on both the proximal sides of thirty freshly extracted mandibular molars and were divided into six groups, according to the type of fiber insert and use of flowable composite (Filtek Z350) as a liner. Filtek P-60 (3M/ESPE) posterior composite was used to restore all cavities. The specimens were thermocycled and stained with 2% Basic Fuchsin dye, and sectioned to evaluate the dye penetration under Stereomicroscope. Statistical analysis was done using Kruskalwallis test and Mann whitney U test.Results and Conclusion:This study showed that, fiber insert groups, with or without flowable liner, had reduced microleakage scores as compared to the control groups. However, statistically no significant difference was found between the groups with fiber inserts. Less microleakage was seen in Group IV (With flowable liner and without Fiber inserts) as compared to Group I (Without flowable liner and Fiber inserts).

“Minimal intervention with maximum dentistry” The immediate restorative technique resolving the acute problem of traumatic tooth fracture with pulpal involvement–An immediate fracture fragment reattachment using pre-fabricated fiber post with dual cure cement–A challenging, conservative, aesthetics, rehabilitating, functionally, and economically viable single visit procedure.

Aim Fracture of restorative composite is reported as a common reason for replacement. Due to failures of this kind, it is still controversial whether restorative composites should be used in large, high-stress-bearing applications, such as in direct posterior restorations. The high brittleness of current composites hinders their use in large stress-bearing areas. Thus, recently short fiber-reinforced composite was introduced as dental restorative composite resin. The aim of the article is to evaluate shear bond strength of fiber-reinforced composite (everX Posterior) and methacrylate-based composite (FILTEK Z250) to pure tricalcium silicate-based cement (biodentine). Materials and methods Acrylic blocks (n = 30) with 2 mm high and 5 mm diameter central holes were prepared. The samples were taken and filled with biodentine and were divided into two groups containing 15 in each group. Group I: Fiber-reinforced composite. Group II: Methacrylate-based composite, which are layered over biodentine. The specimens are transferred to the universal testing machine and subjected to shear bond strength analysis at a cross-head speed of 1.0 mm/minute. Results The bond strength values were significantly higher in case of fiber-reinforced composite when compared with methacrylate-based composite. Conclusion Within the limitations of the study, it was concluded that the fiber-reinforced composite with biodentine had highest bond strength when compared with methacrylate-based composite. Clinical significance Fiber-reinforced composite has excellent fatigue resistance because the embedded fibers are bonded to the polymer matrix and allow the stresses to be distributed effectively throughout the restoration. They are most suitable for applications in which the direction of highest stress is predictable. They are used in cavities with three or more surfaces missing and also in large-sized cavities. They are extensively used in cavities where inlays and onlays are prescribed. How to cite this article Reddy RA, Basavanna RS. Evaluation of Shear Bond Strength of Fiber-reinforced Composite and Methacrylate-based Composite to Pure Tricalcium-based Cement. CODS J Dent 2016;8(1):25-27.

Objectives:To evaluate the incidence of dentinal crack initiation after root canal preparation using four different nickeltitanium (NiTi) rotary instruments.Methods: Sixty single-rooted premolars were selected. A total of 15 teeth were left unprepared and served as a negative control; another 25 teeth were instrumented with the ProTaper universal system up to size F2 as a positive control, and the remaining 30 teeth were shaped with the following experimental groups with an apical size 25 file: ProTaper Next X2 and K3XF 25/0.4. Canals were irrigated with 12 mL of 1% sodium hypochlorite solution and rinsed with 5 mL of distilled water. All the roots were sectioned perpendicular to the long axis at 3, 6 and 9 mm from the root apex and examined under a stereomicroscope at 25X magnification to determine the presence of cracks. Data were analyzed using Fischer's exact test.Results: There was a non-significant difference in the percentage of dentinal crack after biomechanical preparation with NiTi rotary files as compared to the unprepared group except when compared with protaper universal.Interpretation and conclusion: All NiTi rotary files are capable of initiation of cracks during root canal instrumentation. The maximum percentage of cracks occur in the apical section. The percentage of dentinal crack in the apical section is least in ProTaper Next.

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