Quantitative assessment of Mutans Streptococci adhesion to coated and uncoated orthodontic arch wires : in vitro study

Abstract EN

Background : The development of orthodontic biomaterials that attract less bio film has been a goal for decades.

Adhesion and colonization of cariogenic streptococci are considered to play key roles in the development of enamel demineralization related to orthodontic materials.

The aim of this study was to quantitatively evaluate the Mutans streptococci adhesion to coated orthodontic arch wires (Epoxy and Teflon) and uncoated arch wires (stainless steel and nickel-titanium) with respect to incubation time in the presence and absence of saliva.

Material and Method : Six types of arch wires stainless steel and nickel titanium with two type of coating (Epoxy, Teflon) were used in this study.

Twelve specimens of each arch wire were incubated in sterilized un stimulated whole saliva (for the study group) and phosphate-buffered saline (for control group) for 2 hours, then incubated with suspension of Mutans streptococci allowed to adhere for (5, 90, 180 minutes).

Adhesion was quantitated by a microbial culture technique by treating the arch wires with adhering bacteria with trypsin and enumerating the colony forming unit (CFU) counts of bacteria recovered after cultivation by using Dentocult SM kit.

Results : There was significant difference among the tested arch wire types in each time interval with the highest bacterial adhesion on the NiTi arch wires in the absence of saliva.

In the presence of saliva, the results revealed non significant difference at 5 min.

while there was significant difference at 90 min and highly significant difference at 180 min.

Conclusion : The adherence of Mutans streptococci was decreased in the presence of saliva on different arch wires and the extended incubation time was significantly related to increase colony forming unit of Mutans Streptococci.