The effect of surface characteristics and antimicrobial agents on the growth of biofilms on orthodontic mini-screw implants

Shastri, Shaneel (2015) The effect of surface characteristics and antimicrobial agents on the growth of biofilms on orthodontic mini-screw implants. Professional Doctorate (Research) thesis, James Cook University.

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Background: Orthodontic mini-screw implants (OMSIs) have become largely popular in contemporary orthodontics to attain anchorage. However, a high rate of failure of these devices has been one of the disadvantages. One of the potential areas for failure that have been identified may be the aggregation of biofilm of these devices leading to peri-implant inflammation. To date, the investigation into the various surface characteristics of various OMSI systems has been limited. Surface roughness has been identified as a factor involved in biofilm aggregation.

Aim: This study aims to compare the effect of surface characteristics and antimicrobial agents on the growth of biofilms on orthodontic mini-screw implants. The null hypothesis states that there will be no difference in the surface roughness or biofilm growth between implant groups. Furthermore, there will be no difference in the efficacy of antimicrobial agents.

Method and materials: Four OMSIs with various surface finishes available in the Australian market were selected for the present study. They were: Vector – Anodised titanium alloy, TOMAS – machined titanium alloy, Leone – Stainless steel, and Aarhus Anodised titanium alloy. Five implants from each group were selected and tested under atomic force microscopy with a INTEGRA Modular AFM (NT-MDT, Moscow, Russia) and scanning electron microscopy Jeol JSM5410LV (Peabody, Massachusetts, USA) around the head and neck region. Each implant was measured at three random sites. Qualitative and quantitative data were collected for statistical analyses. In a separate arm to the experimental process, biofilm was cultured around each implant group with flow cytometry utilized to determine which implant groups were more conducive to biofilm growth. Antimicrobial agents including Chlorhexidine, and Fluoride were also investigated to determine the effect these would have on biofilm grown on the selected OMSI groups.

Results and Discussion: One way ANOVA revealed that between the implant groups, Vector OMSIs were shown to have the roughest surface (Mean surface roughness of 239.4 ± 71 nm (p<0.00). The roughness of the other groups showed no statistical significance. These findings were reflected in the SEM and bacterial studies which showed the Vector group to have a higher surface roughness as well as leading to increased biofilm growth. Interestingly, the Aarhus group (Mean surface roughness of 127.8 ± 30 nm (p<0.00), whilst not as rough as the Vector group also displayed increased biofilm growth. When comparing antimicrobial efficacy, Chlorhexidine was shown to be greater th[a]n twice as effective as fluoride when used as an antimicrobial agent in controlling biofilm around OMSI.

Conclusions: This study shows that when investigating OMSI, increased surface roughness may result in increased biofilm growth. Anodized titanium alloy surfaces were found to be both the roughest, and most conducive to biofilm grown. This may be a factor in the operator choosing an appropriate OMSI system for use in their patients to limit the amount of biofilm growth. When comparing antimicrobial agents, chlorhexidine remains a better choice to effectively clean OMSI in situ.

Item ID: 43746
Item Type: Thesis (Professional Doctorate (Research))
Keywords: antimicrobial agents; antimicrobials; biofilm growth; biofilms; miniscrews; OMSIs; orthodontic mini-screw implants; orthodontics; skeletal anchorage; surface characteristics; TADs; temporary anchorage devices
Date Deposited: 20 Apr 2016 04:27
FoR Codes: 11 MEDICAL AND HEALTH SCIENCES > 1105 Dentistry > 110506 Orthodontics and Dentofacial Orthopaedics @ 100%
SEO Codes: 92 HEALTH > 9201 Clinical Health (Organs, Diseases and Abnormal Conditions) > 920113 Oro-Dental Disorders @ 100%
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