Related Experiment Videos
Bacterial degradation of composite bonding materials
H J Donker1, B Melsen, E V Frandsen
1Department of Orthodontics, Royal Dental College, University of Aarhus, Aarhus, Denmark; Department of Oral Biology, Royal Dental College, University of Aarhus, Aarhus, Denmark.
Clinical Orthodontics and Research
|September 13, 2001
Summary
This study investigated if bacteria degrade orthodontic bracket composites, causing late bracket failure. Researchers found no significant weight change in composite materials after bacterial incubation, refuting this hypothesis.
Area of Science:
- Orthodontics
- Biomaterials Science
- Microbiology
Background:
- Late bracket failure in orthodontics is typically attributed to mechanical factors.
- A recent hypothesis suggested bacterial degradation of composite resin as a cause for late bracket failure.
- This hypothesis was based on observations of degraded composite on recycled brackets and minor weight loss in lab tests.
Purpose of the Study:
- To investigate the potential for bacterial degradation of composite resins used in orthodontic bonding.
- To examine debonded orthodontic brackets for signs of decay.
- To test the ability of specific bacterial species to degrade composite materials.
Main Methods:
- Examined 1056 debonded orthodontic brackets for signs of decay.
- Incubated composite discs from two brands with five different bacterial species for 3 months.
- Compared weight changes in bacteria-incubated discs against control discs.
Main Results:
- 6.2% of debonded brackets showed signs of decay, including air bubbles, corrosion, and discoloration.
- No significant weight difference was observed between composite discs incubated with bacteria and control discs.
- Bacterial incubation did not lead to measurable degradation of the composite materials.
Conclusions:
- The findings do not support the hypothesis that bacterial degradation causes late bracket failure in orthodontics.
- Observed decay on brackets is likely not due to bacterial action on the composite resin.
- Mechanical factors remain the primary explanation for late bracket loss.