Can proteins cure dental cavities?

The Effect of Shade and Thickness on the Depth of Cure of Bulk-Fill Composites with Different Viscosities

STATEMENT OF THE PROBLEM

In an attempt to enhance and simplify the restoration process, a new class of composite resins, called the bulk fill composite resins have been introduced. It is claimed that a depth of cure (DOC) of 4 mm can be achieved without affecting the properties of this material.

PURPOSE

The purpose of this study was to investigate the effect of different shades, thicknesses, and viscosities on the DOC of bulk-fill composites.

MATERIALS AND METHOD

In this experimental study, four bulk-fill composites [Filtek™ Bulk Fill Flowable (FBF), Filtek™ Bulk Fill posterior (FBP), Tetric® N-Flow Bulk Fill (TNF), Tetric® N-Ceram Bulk Fill (TNC)] and a conventional composite, Filtek™ Z250 XT Universal (FZ) were evaluated. The samples (n=5) were made using two different shades (light and dark), thicknesses (2 and 4mm), and viscosities (flowable and sculptable). Microhardness test was conducted on top and bottom surface using Vickers microhardness tester and DOC was calculated as the bottom/top ratio of yielded scores. Statistical analysis was done using a Mann Whitney test at p< 0.05.

RESULTS

DOC ranged between 52-95%. FBF composite exhibited the lowest overall hardness numbers. At 2-mm thickness, all the samples achieved an appropriate DOC. However, at 4mm thickness, only the light shades for FBF and TNF samples achieved a DOC very close to 0.8. At 4-mm thickness, the light shades for FBF, TNF and FZ samples exhibited significantly higher DOC compared to dark shades. For 4-mm-thick samples, the DOC of Filtek™ Bulk Fill (dark and light shades (and the DOC of Tetric® Bulk Fill (light shade (were different in flowable type from the sculptable type.

CONCLUSION

The shade and the viscosity of bulk-fill composites influence their DOC at 4-mm depths. Moreover, 20 seconds of light curing appears insufficient for 4mm thickness of bulk-fill composite.

Subsurface enamel remineralization by Lyophilized Moringa leaf extract loaded varnish

OBJECTIVE

The objective of this study was to investigate enamel remineralization using lyophilized extract from Moringa Oleifera Leaves (MOL).

MATERIALS AND METHODS

A total of seventy-five teeth were selected and randomly divided into 5 equal groups (n = 15). All teeth were air dried for 30 s, two windows (right and left) were drawn on the labial surface of each tooth. The right window was set as the control and no etching or treatment was performed. The left window was etched for 30 s for all five groups. After etching, group I received no treatment, group II received plain varnish, group III received fluoride varnish, and finally groups IV and V received plain varnish loaded with 50 mg/ml and 200 mg/ml of lyophilized MOL extract respectively. All samples were then immersed in artificial saliva for 14 days. The specimens were examined under scanning electron microscope (SEM) and energy dispersive x-ray (EDX).

RESULTS

SEM micrographs revealed that MOL extract loaded-varnish groups IV & V showed the most re-establishment of normal enamel architecture. Elemental analysis of the treated surfaces of Groups IV and V showed the surfaces treated by MOL loaded-varnish groups had significantly higher Ca, P, and O deposition than the fluoride varnish group.

CONCLUSION

MOL might be considered as a biomimetic material capable of guiding enamel tissue remineralization.