Bacterial plaque retention on oral hard materials: Effect of surface roughness, surface composition, and physisorbed polycarboxylate

Abstract

Bacterial adhesion to oral hard materials is dependent on various factors, for example, surface roughness and surface composition. In this study, bacteria retention on three oral hard substrates, hydroxyapatite (HAP), enamel, and polished enamel (p-enamel) were investigated. The surface morphology and roughness of the three substrates were measured by scanning probe microscopy. HAP had the roughest surface, followed by enamel and polished enamel. For each individual substrate type, the roughness was shown to increase with scan size up to 50 microm x 50 microm. For HAP and enamel, roughness decreased considerably after formation of a pellicle, while addition of polymer coating to the pellicle layer reduced roughness much less in comparison. Bacterial surface coverage was measured at 30 min, 3 h, and 24 h on both native and surface-modified substrates, which were coated with two different polycarboxylate-based polymers, Gantrez S97 and Carbopol 940. As a result, the polymer coated surfaces had reduced bacteria coverage compared with the native surfaces over all time points and substrates measured. The reduction is the combined effect of electrostatic repulsion and sequestering of Ca(2+) ions at the surface, which plays a key role in the initial adhesion of bacteria to enamel surfaces in models of plaque formation.

In vitro evaluation of surface roughness, adhesion of periodontal ligament fibroblasts, and Streptococcus gordonii following root instrumentation with Gracey curettes and subsequent polishing with diamond-coated curettes

“…In our study, the specimens were covered with serum first to simulate the in vivo conditions which may weaken surface irregularities. Saliva reduced the surface roughness of hydroxyapatite; further, the initial bacterial adhesion was lower at polished enamel having an extremely smooth surface in comparison to hydroxyapatite [30]. In a clinical study using a split-mouth design placing titanium abutments with different roughness Fig.…”

Rechargeable calcium phosphate orthodontic cement with sustained ion release and re-release

“…However, the entire etched enamel surface usually cannot be completely covered by orthodontic cement because it is clinically impossible to visualize the small area of etched enamel. The etched enamel surface, not covered by the orthodontic cement is vulnerable to the retention of oral micro-organisms and the resultant demineralization that results in WSL and caries45. Mature enamel is an acellular matrix, thus it is impossible to regenerate after trauma or decay46.…”

Surface roughness and morphology of resin composites polished with two-step polishing systems

“…The natural gloss and final esthetic of the restoration, abrasivity and wear kinetics 1) ; improved mechanical properties 2) ; and tactile perception and comfort of the patient 3) are highly associated with surface properties. Moreover, smooth surfaces and margins reduce the risk of biofilm adhesion and maturation, recurrent caries, gingival irritation [4][5][6][7][8] and staining 9) . The smoothest possible surface is obtained when the resin composite polymerizes against a Mylar matrix without subsequent finishing or polishing 10,11) ; however, such a surface has a resin-rich layer, poor mechanical properties, is susceptible to increased wear and discoloration and should be eliminated 2,9) .…”