Bacterial Flora in Screw-Fixed Superstructures with Different Sealing Materials: A Comparative Clinical Trial

Area of Science:

• Dental Implantology
• Microbiology
• Biomaterials Science

Background:

• Screw-fixed superstructures are common in implant prostheses due to concerns about peri-implantitis.
• The specific infection route for peri-implantitis, particularly microleakage from access holes, requires further clinical investigation.

Purpose of the Study:

• To clinically investigate the bacterial flora within dental implant access holes.
• To compare the efficacy of different sealing materials, specifically composite resin versus zinc-containing glass ionomer cement, in managing bacterial contamination.

Main Methods:

• A clinical study involving 38 sites in 19 patients with screw-fixed superstructures.
• Access holes were sealed with either composite resin (control) or zinc-containing glass ionomer cement (test).
• Bacterial samples were collected 28 days post-placement and analyzed using DNA hybridization.

Main Results:

• Zinc-containing glass ionomer cement significantly decreased bacterial counts in 14 species across red, yellow, and purple complexes (p < 0.05).
• This material also significantly reduced bacterial ratios in six species from orange, green, yellow, and purple complexes (p < 0.05).
• Implant positivity rates for six bacterial species in orange, yellow, and purple complexes were significantly lower in the test group.

Conclusions:

• Zinc-containing glass ionomer cement demonstrates effectiveness as a sealing material for dental implant access holes.
• This biomaterial shows potential in mitigating bacterial ingress and reducing the risk of peri-implantitis.
• The findings support the use of zinc-containing glass ionomer cement for improved dental implant maintenance.