Effect of various treatment and glazing (coating) techniques on the roughness and wettability of ceramic dental restorative surfaces

Abstract

Surface treatment procedures such as grinding and polishing are needed to provide the ceramic dental restorative materials with proper fitting and occlusion. The treated surfaces are customarily glazed to improve the strength and smoothness. Though smoothness and wetting of the dental surfaces are important to minimize bacterial plaque retention, influence of the surface treatment and glazing procedures on the final surface roughness and its correlation to wettability are overlooked.In this work, effect of various treatment (diamond fraising, stoning, sanding and aluminum oxide and rubber polishing) and glazing (auto and overglazing) techniques on the final roughness and the resulting wettability of dental ceramic surfaces were investigated using scanning electron microscopy (SEM) observations and atomic force microscopy (AFM) scans, 75 scans per sample. The surfaces were characterized and assigned an average roughness measure, R a . The wettability of the same surfaces was evaluated using micro-contact angle measurements (25 micro-bubbles placed on a grid on each surface) to correlate the final surface roughness and wettability.The results show that overglazing prevails over surface irregularities from different treatment procedures and provides homegeneously smooth surfaces with mean R a < 10 nm. It also produces uniformly wetted surfaces with low contact angles around 20 • . The autoglazed surfaces are less smooth (mean R a around 50 nm) and displays sporadic topographic irregularities. They display larger and less uniform contact angles ranging between 35 • and 50 • . The results suggest that overglazing should be preferred after surface treatment to obtain a smooth and well-wetted dental ceramic surface.

Effect of overglazed and polished surface finishes on the compressive fracture strength of machinable ceramic materials

“…2). This finding agreed with those of previous studies which examined the effects of polishing and overglazing on the roughness of dental ceramic surfaces 14,29) . Nevertheless, surface pores, which could act as starting points of crack growth, were observed even on the glazed specimens, especially those made of Vita Mark II and IPS e.max CAD (Fig.…”

“…On the preferred surface treatment for ceramic restorations, glazing is generally advocated to improve their strength 2,12,13,26,27) and reduce their surface roughness 12,16,26,[28][29][30] . The reinforcing effect of glazing is believed to be due to a reduction in the depth and sharpness of surface flaws and porosities, which can otherwise be critical fracture origins 31) .…”

Confocal Laser Microscopic Analysis of Biofilm on Newer Feldspar Ceramic

“…Other authors mentioned that glaze resulted in a smoother, more hydrophobic surface when compared to surfaces that received other polishing techniques. 40 Glazed ceramic (G1) was more hydrophobic and smooth when compared to glazed ceramic finished with a bur and polished with rubber tips and felt disks (G4). Nevertheless, G1 and G4 presented similar mean thicknesses and biovolumes of biofilm.…”

Determination of the particle interactions, rheology and the surface roughness relationship for dental restorative ceramics

“…10 Therefore, the degree of surface roughness of dental ceramics is extremely important and its effect on biocompatibility has been widely studied. [11][12][13][14][15][16][17][18][19][20] Microcracks which develop during the firing of these ceramics contribute to surface roughness while decreasing the strength of the restorative material due to stresses accumulating within the crack sites. Both factors significantly reduce the performance of the ceramic restorative materials in oral environment.…”