Technological improvements and the progress of new adhesive materials have led to the development of minimally
invasive restorations, like overlays; these are also indicated in the treatment of pathological tooth wear caused by
bruxism. In this study we evaluated the marginal adaptation of Tizian overlays through two non-invasive methods:
digital microscopy and confocal laser scanning microscopy. 12 maxillary first premolars were extracted and prepared for
overlays. The Tizian overlays were cemented with Variolonk II (Ivoclar Vivadent). The marginal adaptation of each
specimen was analyzed, on all four surfaces, with a digital microscope at 40x to 800x magnification ratio; we also used
a confocal laser scanning microscope, at 10x magnification, in Z mode, with 10 μm slices and a resolution of 1020 x
1024. The exposure time per pixel was 8 μs and the wavelength of the laser was set at 405 nm, corresponding to a blue
light laser. We concluded that confocal laser scanning microscopy, with its a higher horizontal and vertical resolution
with regard to digital microscopy, and with its volumetric reconstructions capability of the sample image, is therefore a
more appropriate method for this particular dental field, i.e., to investigate the marginal adaptation of Tizian overlays.
The aim of this study was to evaluate a relatively new calcium silicate cement (Biodentine(R)) used as a dentine substitute. The marginal adaptation in Class II restorations have been studied; this is the spot, where gingival margins are situated apical to the cemento-enamel junction (CEJ). 20 Class II cavities have been prepared on mesial and distal surfaces of 10 extracted teeth, with margins extending 1 mm below the cementum-enamel junction. Cavities have been restored with composite resin and Biodentine(R) in an "open sandwich" technique. The assessment of the marginal adaptation was performed using Laser Scanning Confocal Microscopy. The considered interfaces have been evaluated and the differences between the different materials have been discussed. In conclusion, contemporary calcium silicate materials, such as Biodentine, can be used as substitute materials for the dentin. However, because Biodentine needs extensive time to set, the operating time is longer than when a Resin-Modified Glass-Ionomer (RMGI) is used.
Prevention and allopathic medicine gained attention, since it is possible for dentists to prevent demineralization, using plants and natural substances with well-known efficacy. The purpose of this study was to present new methods for teeth remineralization. It was made a selection of 10 extracted teeth, maintained in physiological serum, with no color fading, decay or demineralization. It was induced demineralization, with ortho-phosphoric acid (concentration 45 %), for one minute. The probes were visually and with optical coherence tomography (OCT) inspected. The natural product and the bonding with additional nanoparticles of argent were created and applied on the demineralization zone of the both groups of teeth. Each tooth in the first group had one plain surface demineralized. The second group of teeth had a cavity prepared on one of each tooth’s side. The pastes were applied on the demineralized surfaces and in the demineralized cavities for two minutes. After time expired, the pasta applied on the first group of teeth was washed away; the bonding above the second group of teeth was light cured. The probes were again visually and with OCT inspected. It was observed an improvement in remineralizing the white marks on plain surfaces and in the created cavities, the OCT being able to detect different levels of remineralization. The efficacy of natural pasta depends on the time it is applied and the concentration of the different main substances. Also, the type of surface, plain or occlusal facets, may influence the substances’ penetration ability. The non-invasive specific feature of these products, low costs and safety are strong positive aspects of this method of remineralization. However, the natural process of remineralization is a long-lasting one; perfecting the main substances in order to accelerate the process, in addition to several in vivo studies would be necessary to be fulfilled.
In clinical dental practice it is often difficult or even impossible to distinguish and control interfacial adhesive defects from adhesive restorations using visual inspection or other traditional diagnostic methods. Nonetheless, non-invasive biomedical imaging methods like Optical Coherence Tomography (OCT) may provide a better view in this diagnostic outline. The aim of this study is to explore evaluations of the marginal adaptation of class I resin composites restorations using Time Domain (TD) OCT. Posterior human teeth have been chosen for this study. The teeth were stored in 0.9% physiological saline solution prior to use. A classical round-shaped class I cavity was prepared and cavities were restored with Charisma Diamond composite by Heraeus Kulzer and using a system of etch and rinse boding. The specimens were subjected to water storage and then to thermo-cycling. Three dimensional (3-D) scans of the restoration were obtained using a TD-OCT system centered at a 1300 nm wavelength. Open marginal adaptation at the interfaces and gaps inside the composite resins materials were identified using the proposed method. In conclusion, OCT has numerous advantages which justify its use for in vitro, as well as for in vivo studies. It can therefore be considered for non-invasive and fast detection of gaps at the restoration interface.