The Influence of Surface‐Free Energy on Supra‐ and Subgingival Plaque Microbiology. An In Vivo Study on Implants

Abstract

The influence of surface free energy on supra‐ and subgingival plaque microbiology was examined in 9 patients with functional fixed prostheses supported by endosseous titanium implants. Two abutments (trans‐mucosal part of the 2 stage implant) were replaced by either a new titanium abutment or a fluor‐ethylene‐propylene (FEP) coated abutment per subject. After 3 months of habitual oral hygiene, plaque samples were taken. Supragingival plaque was examined by means of differential phase‐contrast microscopy, whereas for the subgingivial plaque additional analyses (DNA probes analysis, culturing) were performed. The subgingival samples were taken by paper‐points and by scraping of the subgingival abutment surface. Differential phase‐contrast microscopy showed a significant difference in plaque composition, especially when supragingival plaque was considered (P = 0.05). FEP coated abutments frequently harbored more coccoid microorganisms, whereas spirochetes or motile organisms were only detected around titanium abutments. Subgingivally, the number of colony forming units (CFU) in paper‐points was comparable for both types of abutments. If the to‐the‐abutmentadhering plaque was considered, the number of CFU was 5 times higher on the titanium abutments than on the FEP coated abutments. However, this difference did not reach a statistical level of significance (P = 0.38). The DNA probe analysis of the subgingival plaque collected with paper‐points showed a slightly higher frequency and concentration of perio‐pathogens around the titanium abutments. However, the inter‐substratum differences were smaller than the inter‐subject differences. The latter seemed to be related to patient's dental status. These results indicate that lowering the surface‐free energy of intra‐oral hard surfaces results in a reduction in bacterial colonization and in a retardation in its maturation in the supragingival area. For the subgingival area, the influence of this surface characteristic is not as obvious. J Periodontol 1994; 65:162–167.

Influence of surface modifications to titanium on oral bacterial adhesionin vitro

“…Drake et al 24 showed that hydrophobic titanium surfaces were preferentially colonized by Streptococcus sanguis. In contrast, Quirynen et al 3 reported that the amount of bacterial adhesion decreased on a fluorethylenepropylene coated group, in which the surfaces were hydrophobic. The results of this study also showed that P.g.…”

“…1 Comparatively large amounts of bacterial adhesion and plaque formation on titanium implants have been reported under in vitro and in vivo tests, and the necessity for plaque control has been pointed out. [2][3][4][5][6] However, there are few reports on the relationship between bacterial adherence and the physicochemical nature of implant surfaces. Moreover, few experiments have been conducted with surface modification to inhibit the adherence of oral bacteria on titanium implants.…”

Effects of various chair-side surface treatment methods on dental restorative materials with respect to contact angles and surface roughness

“…These results are confirmed by other investigators who state that increasing surface roughness not only increases plaque retention 23,24,28,36,44) but also leads to plaque adhering much more rapidly and in larger quantities 20,25) . Comparing all influencing factors, several studies concluded that surface roughness plays the most important role in initial bacterial adhesion and the influence of surface roughness exceeds the influence of surface free energy 23,29,30,34,37) . Carlen et al state that polishing procedures lead to an unfavorable surface with lower protein resistance that is thus more prone to accumulate biofilms.…”

“…Conflicting reports relate plaque formation to substratum hydrophobicity. Some previous studies conclude that dental plaque formation is greater on hydrophilic restorative materials such as porcelain and metals than on hydrophobic materials such as amalgams and resins 25,29,[33][34][35] . Contrary studies, however, report greater plaque formation on hydrophobic materials and significantly lower adhesion to ceramics than to composite resin surfaces of polymeric origin or amalgams [36][37][38][39] .…”

The Use of Positively Charged or Low Surface Free Energy Coatings versus Polymer Brushes in Controlling Biofilm Formation

“…Another study indicated, that after three months the exposed areas of low s.f.e. FEP coated abutments (transmucosal dental implants) displayed lower bacterial colonization and a lower plaque maturation as compared to bare titanium [43]. However, in the areas covered by the gingiva, where less mechanical shear forces are present, this effect was not apparent.…”