Investigation of Peri-implant Microflora in Patients with Orthodontic Implant Anchorage

Objectives: The objective of this prospective study was to investigate changes in the peri-implant microflora of patients with skeletal anchorage (Palatal Implant, Straumann, Basel, Switzerland).

Methods: Fourteen patients (aged 12 to 28 years) in whom orthodontic treatment had required stationary anchorage were included in the study. All implants had been inserted in the median region of the anterior palate. Twelve implants were subjected to functional loading for at least 6 months. Pathogens were determined after 1 and 6 weeks (healing phase) as well as 2 and 6 months after functional loading (oligonucleotide probe test, IAI Pado test 4.5, Institute for Applied Immunology, Zuchwil/ Switzerland). The detection limit for Bacteroides forsythus, Porphyromonas gingivalis and Treponema denticola was 10⁴ while that for Actinobacillus actinomycetemcomitans was 5x10³.

Results: All implants were stable during the investigation period. Colonization with typical peri-implantitits-associated pathogens was noted during the healing phase. Bacteroides forsythus (7/14) and Porphyromonas gingivalis (4/14) were found. Treponema denticola and Actinobacillus actinomycetemcomitans were only observed in 2 of 14 implants. Two and 6 months after functional loading, colonization with pathogens was noted in 4 implants (p=0.096; Wilcoxon test of pairwise differences).

Conclusions: Colonization with typical peri-implantitis-associated pathogens occurs quite early in the case of palatal implants. Despite complex suprastructures and oral hygiene rendered difficult by the appliance, the extent of such colonization was reduced under functional loading and did not affect the stability of anchorage during the investigation period.