Document Type


Peer Reviewed


Publication Date


NLM Title Abbreviation

J Adv Prosthodont

Journal/Book/Conference Title

Journal of Advanced Prosthodontics

PubMed ID


DOI of Published Version


Start Page


End Page



PURPOSE: The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time.

MATERIALS AND METHODS: This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week (t1) and 4 months (t2) after the RPD was inserted (t0). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity).

RESULTS: A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 (t1) and 96 (t2) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for t1 and 17 for t2, which were grouped in 5 phyla: Firmicutes (t1=82%; t2=60%), Actinobacteria (t1=5%; t2=10%), Bacteroidetes (t1=2%; t2=6%), Proteobacteria (t1=10%; t2=15%) and Fusobacteria (t1=1%; t2=8%). The libraries also include 3 novel phylotypes for t1 and 11 for t2. Library t2 differs from t1 (P=.004); t1 is a subset of the t2 (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in t2.

CONCLUSION: The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions.


16S rDNA gene, Denture plaque, Framework, Microorganism, Removable partial denture

Granting or Sponsoring Agency

The State of Sao Paulo Research Foundation, Brazil

Grant Number


Journal Article Version

Version of Record

Published Article/Book Citation

J Adv Prosthodont. 2015 Dec;7(6):468-474.


Copyright © 2015 The Korean Academy of Prosthodontics. Posted by permission.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 3.0 License