The aim of the article is to present a narrative review of the literature related to the different shade guides available for dental practitioners.A literature search was performed in the online databases -PubMed, Science Direct, MedLine and GoogleScholar with the following keywords -shade guide, shade matching, dental, dentistry. Furthermore, a hand search, including "grey" literature and printed resources available to the authors, was conducted. More than 2100 unique articles, including the selected keywords, were identified. After a critical review and elimination process, 39 of the papers were included.Dental shade guides are a set of colour standards mimicking the colour of tissues, which dentists aim to restore -tooth structures, gingival tissues or facial structures in facial prosthodontics -skin, mucosa, eyes etc. They can be systematized based on the following principles -fabrication process, the material of manufacturing or restoration and according to the tissues, which are restored.The most commonly used shade guides in the dental practice are structured around Munsell's 3-dimensional colour system and are aimed at the restoration of tooth colour. The colour standards for gingival and facial restoration are not routinely utilized since they are aimed at specialists in prosthetic dentistry and facial prosthodontics and are underdeveloped to some degree in comparison with the aforementioned.The contemporary development in aesthetic restorative materials and procedures requires an adequate follow up in the evolution of shade guides since they present the only means of communication between the dental office and laboratory.
Purpose: This study investigates the hydrofluoric acid etching patterns and the surface morphology of three types of glass-ceramic materials. Materials and methods: Hydrofluoric acid etching patterns and surface morphology changes of three silica-based ceramics - EX-3, E.max press, and Heraceram press were studied. Fourteen rectangular experimental bodies with a cross-section of 2x2mm and a length of 5-7 mm were divided into two groups(n=7): polished (control group) and etched (5% hydrofluoric acid). Etching time was 120s in EX-3 (EXHF) and Heraceram press (HHF) groups and 20s in E.max press group (EHF). Surface morphology was observed under a scanning electron microscope at magnifications ranging from x50 to x2700. Results: The presence of numerous pores and channels as a result of the etching procedure was observed in all ceramic materials. In the EXHF group, irregularly shaped structures and canals with a width of 10-20µm characterize the ceramic surface. At higher magnifications, microwells with a size of 1-2 µm and channels with a length of 5-10 µm were observed. In the EHF group, lithium disilicate crystals with different orientations and the glassy phase dissolved between them can be seen. Channels with a wavy course and a length of about 5 µm are also observed. In the HHF group, 5-20µm cavernous-like formations surrounded by partially dissolved channels can be seen. Conclusions: Each ceramic material showed different etching patterns due to the material's composition and the distribution of the crystalline and vitreous phases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.