Clinical and microbiologic effects of lingual cervical coverage by removable partial dentures.
OBJECTIVE
The effect of gingival coverage by removable partial dentures (RPDs) on bacterial accumulation has not been sufficiently established. The aim of this study was to evaluate the periodontal and microbiologic reactions to mandibular major connectors. It was hypothesized that the use of a lingual plate increases the risk of periodontal disease.


METHODS
Fourteen subjects (mean age: 69.0 years) received oral hygiene instructions and ultrasonic debridement prior to examination. Each subject received an experimental RPD incorporating either a lingual bar or lingual plate for the first 8 weeks and was then switched to the other option for the next 8 weeks. Clinical parameters (Plaque Index, Gingival Index, probing depth, and tooth mobility) were recorded. Subgingival plaque samples were collected from the periodontal pocket in the test site to measure the colonization of periodontal pathogens after the use of each denture.


RESULTS
The mean probing depth was significantly greater after use of the lingual plate compared to the lingual bar (P < .05), whereas the type of connector did not affect the levels of any of the microbial species. All subjects that exhibited at least one bacterial species showed smaller numbers of microorganisms at the second examination than at the first.


CONCLUSIONS
The lingual cervical coverage did not precipitate the accumulation of anaerobic microorganisms, although it could potentially induce gingival inflammation. The results suggest that a lingual plate can be used as safely as a lingual bar if oral and denture hygiene are carefully monitored.
Tokyo Medical and Dental University, Tokyo, Japan.
Aiichiro
A
Ao
Noriyuki
N
Wakabayashi
Hiroshi
H
Nitta
Yoshimasa
Y
Igarashi
D000368:Aged; D016976:Aggregatibacter actinomycetemcomitans / Q000302:isolation & purification; D058491:Bacterial Load; D001439:Bacteroides / Q000302:isolation & purification; D003773:Dental Plaque / Q000382:microbiology; D003774:Dental Plaque Index; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation*; D003832:Denture, Partial, Removable / Q000382:microbiology*; D005881:Gingiva / Q000382:microbiology*; D006801:Humans; D009910:Oral Hygiene; D010353:Patient Education as Topic; D057747:Periodontal Debridement; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D018713:Prevotella intermedia / Q000302:isolation & purification; D014086:Tooth Mobility / Q000145:classification / Q000382:microbiology; D048373:Treponema denticola / Q000302:isolation & purification; D014465:Ultrasonics