title: Root-surface caries in rats and humans: inhibition by a non-antimicrobial property of tetracyclines.
abstract: The incidence of root caries has been found to increase as the population ages and as edentulism becomes less prevalent due to improved dental awareness and care, and as exposure of roots due to gingival recession has also increased in the elderly. The mechanism of root caries is thought to be mediated by both bacterial and mammalian proteases produced by plaque and the periodontal tissues, respectively. In the current study, a rat model of periodontal disease was used in which gnotobiotic rats were infected intra-orally with a periodontal pathogen (P. gingivalis). Infecting the rats with P. gingivalis increased the collagenase activity in the gingival tissue in association with severe alveolar bone loss. Treating P. gingivalis-infected rats with doxycycline or CMT-1 prevented the destruction of the periodontium by MMPs, thus preventing exposure of roots to subgingival bacterial plaque and host tissue collagenases and the subsequent development of root caries. In addition, a low-dose doxycycline (LDD, 20 mg bid, non-antimicrobial dose) for 3 months was used in humans predisposed to increased root caries as the result of heavy use of smokeless (chewing) tobacco, causing gingival recession, subgingival plaque accumulation with Gram-negative bacteria, increased gingival crevicular fluid flow (GCF), and elevated GCF collagenase. Daily administration of LDD in smokeless tobacco patients reduced the GCF collagenase and prevented the further development of root caries.
authors.affiliation: Department of Oral Biology and Pathology, School of Dental Medicine, SUNY at Stony Brook 11794-8702, USA.
authors.forename: N S
authors.initials: NS
authors.lastname: Ramamurthy
authors.forename: K L
authors.initials: KL
authors.lastname: Schroeder
authors.forename: T F
authors.initials: TF
authors.lastname: McNamara
authors.forename: A J
authors.initials: AJ
authors.lastname: Gwinnett
authors.forename: R T
authors.initials: RT
authors.lastname: Evans
authors.forename: C
authors.initials: C
authors.lastname: Bosko
authors.forename: L M
authors.initials: LM
authors.lastname: Golub
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017364:Collagenases / Q000378:metabolism; D004318:Doxycycline / Q000494:pharmacology / Q000627:therapeutic use*; D005881:Gingiva / Q000201:enzymology; D005889:Gingival Recession / Q000209:etiology; D006801:Humans; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors; D010510:Periodontal Diseases / Q000382:microbiology / Q000517:prevention & control*; D010947:Plants, Toxic; D016966:Porphyromonas gingivalis / Q000187:drug effects; D011480:Protease Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017213:Root Caries / Q000382:microbiology / Q000517:prevention & control*; D013752:Tetracycline / Q000494:pharmacology / Q000627:therapeutic use*; D014030:Tobacco, Smokeless / Q000009:adverse effects