Fixed twin block-a fixed functional appliance, used in orthodontic therapy serves as a surface for microbial colonisation. The microorganisms organised as biofilms are protected from harmful environmental factors and an increased risk of disease may be its direct consequence.
Fixed Twin Block appliances of 21 healthy children among the ages of 11 to 15 years were taken to evaluate the different types of microorganisms associated with biofilm formation on this functional appliance at baseline, 1st, 3rdmonth and 6thmonths. For isolation of microorganism from biofilms different types of selective and nonselective medium based on standard methods were used. The percentage frequencies of isolates were also calculated.
Gram positive cocci- S. mutans, S. mitisand other Streptococcus sp., Gram-negative Facultative anaerobic rods of Enterobacteriaceae sp. like Enterobacter faecalis, Klebsiella pneumoniae, Escherichia coli, proteus, citrobactor; Obligate anaerobic rods- Porphyromonas gingivalisand Prevotella intermedia, Gram positive facultative anaerobic rods like lactobacilliand actinomyces; and Candida albicanswere found in the samples. Statistically significant elevated levels of S. mutans, S. mitis, other streptococci, Actinomyces spp, Candida sp., E. coliwith increase in time show peak values at six months except for S. mitisand other streptococci sp.
The employment of fixed acrylic based Twin Block appliance can represent a factor promoting the colonisation of the oral cavity by various micro-organisms and stresses the need of a careful monitoring of orthodontic patients for the risk of development of various plaque associated diseases and institution of preventive measures for the same.