title: Effects of surface properties of polymer-based restorative materials on early adhesion of Streptococcus mutans in vitro.
abstract: We investigated the effects of the surface properties of polymer-based restorative materials on early adhesion of Streptococcus mutans (UA159) in vitro.
  
  
  
  Four direct polymer-based restorative materials, including a nanoparticle restorative (Filtek™ Z350, 3M ESPE, USA), a nano hybrid universal restorative (Filtek™ Z250 XT, 3M ESPE, USA), a low shrink posterior restorative (Filtek™ P90, 3M ESPE, USA) and a polymer-based pre-reacted glass ionomer (Beautifil II, Shofu, Japan), were selected. After polishing under different conditions, surface morphology was examined using scanning electron microscopy. Surface roughness (SR), water contact angle (CAW) and surface free energy (SFE) were determined by profilometry and the sessile drop method. Early adhesion of S. mutans was investigated using confocal laser scanning microscopy. The area occupied by adherent bacteria (A%) was calculated with COMSTAT2 software. The correlations between A% and SR, CAW, and SFE were analyzed by linear regression using SPSS 20.0 software at a significance level of 0.05.
  
  
  
  The value of A% was strongly correlated with SR (r=0.893, P<0.01) for surface roughness (Ra) of 0.02-0.80μm, whereas a weaker correlation was obtained between A% and SR when Ra≤0.20μm (r=0.643, P < 0.01). On super smooth surfaces (0.02μm≤Ra≤0.06μm), SR did not influence early bacterial adhesion (r=0.001, P>0.05), a medium positive correlation between A% and SFE was obtained (r=0.426, P<0.01), and no correlation between A% and CAW was found (r=-0.028, P>0.05) CONCLUSIONS: Early adhesion of S. mutans on direct polymer-based restorative materials was mainly affected by SR. SFE influenced early adhesion of S. mutans on super smooth surfaces, while hydrophobicity did not.
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Chongyang
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China. Electronic address: wangxiaoyan@pkuss.bjmu.edu.cn.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Gao
authors.affiliation: Department of Central Laboratory, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.affiliation: Research and Development Department, Advanced Technology & Materials Corporation Ltd., Beijing 100094, China.
authors.forename: Xinjie
authors.initials: X
authors.lastname: Liang
authors.affiliation: Research and Development Department, Advanced Technology & Materials Corporation Ltd., Beijing 100094, China.
authors.forename: Dehui
authors.initials: D
authors.lastname: Li
mesh_terms: D001422:Bacterial Adhesion; D003188:Composite Resins; D007564:Japan; D008422:Materials Testing; D011108:Polymers; D013295:Streptococcus mutans; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D011108:Polymers
keywords: Bacterial adhesion; Confocal laser scanning microscopy; Polymer-based restorative materials; Surface properties