Surface characteristics of orthodontic materials and their effects on adhesion of mutans streptococci.
OBJECTIVE
To test the hypothesis that there are no significant differences in the adhesion of mutans streptococci (MS) to various orthodontic materials based on their surface characteristics.


METHODS
Surface roughness (SR) and surface free energy (SFE) characteristics were investigated for nine different orthodontic materials (four orthodontic adhesives, three bracket raw materials, hydroxyapatite blocks, and bovine incisors) using confocal laser scanning microscopy and sessile drop method. Each material, except the bovine incisors, was incubated with whole saliva or phosphate-buffered saline for 2 hours. Adhesion assays were performed by incubating tritium-labeled MS with each material for 3 or 6 hours.


RESULTS
Orthodontic adhesives had higher SFE characteristics and lower SR than bracket materials. Orthodontic adhesives showed a higher MS retaining capacity than bracket materials, and MS adhesion to resin-modified glass ionomer and hydroxyapatite was highest. Extended incubation time increased MS adhesion, while saliva coating did not significantly influence MS adhesion. SFE, specifically its dispersive and polar components, was positively correlated with MS adhesion, irrespective of saliva coating.


CONCLUSIONS
The hypothesis is rejected. This study suggests that SFE characteristics play an important role in the initial MS adhesion to orthodontic materials.
Lee
Seung-Pyo
SP
Department of Oral Anatomy, Seoul National University, Seoul, Korea.
Lee
Shin-Jae
SJ
Lim
Bum-Soon
BS
Ahn
Sug-Joon
SJ
D000537:Aluminum Oxide / Q000737:chemistry; D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D001672:Biocompatible Materials / Q000737:chemistry; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry; D003738:Dental Cements / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D044622:Dental Pellicle / Q000502:physiology; D017886:Durapatite / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D007180:Incisor / Q000382:microbiology; D008422:Materials Testing; D018613:Microscopy, Confocal; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry; D012463:Saliva / Q000502:physiology; D012965:Sodium Chloride / Q000737:chemistry; D013193:Stainless Steel / Q000737:chemistry; D013295:Streptococcus mutans / Q000502:physiology*; D013499:Surface Properties; D013500:Surface Tension; D013997:Time Factors; D017155:Wettability
D001672:Biocompatible Materials; D003188:Composite Resins; D003722:Dental Alloys; D003738:Dental Cements; D003764:Dental Materials; D005899:Glass Ionomer Cements; D019279:Resin Cements; D013193:Stainless Steel; D012965:Sodium Chloride; D017886:Durapatite; D000537:Aluminum Oxide