Days Of Oral Hygiene Research Articles

Gingival crevicular fluid inflammatory mediators and bacteriology of gingivitis in nonhuman primates related to susceptibility to periodontitis.

The hypothesis to be tested was that the microbiota and resulting local host inflammatory response characteristics in oral conditions of high levels of chronic gingival inflammation increases susceptibility to progressing periodontitis. This study used cynomolgus monkeys, Macaca fascicularis (nonhuman primates), with high and low levels of long-standing gingival inflammation to define the profiles of gingival crevicular fluid mediators, cytokines and immunoglobulins; describe the subgingival microbiota; and evaluate their susceptibility to ligature-induced periodontitis. Sixteen nonhuman primates were stratified into two groups (HI, LO) based upon Bleeding Index as a measure of the natural level of inflammation (HI = 1.26 +/- 0.45; LO = 0.22 +/- 0.16). The host mediator levels, subgingival microbiota, and clinical characteristics of the LO and HI groups were compared after 30 days of oral hygiene, during a 30 day experimental gingivitis (7, 14, and 30 days), and during periodontitis (30, 60, and 90 days). The results demonstrated that nonhuman primates with high levels of long-standing gingival inflammation when compared to those nonhuman primates with low inflammation show: 1) different inflammatory mediator profiles in gingival crevicular fluid (particularly for immunoglobulin A (IgA) and IgG levels), 2) a different quantitative and qualitative subgingival microbiota; and 3) a similar progression of periodontitis. Thus, while variations in host inflammatory responses to local factors exist in the nonhuman primates, an extensive subgingival challenge (such as ligation) may negate these individual differences.

Experimental caries in man.

The purpose of the present study was to develop a method for short-term caries trials in man, using an experimental model already employed in periodontal research. Twelve students were given prophylaxis and instruction to practice meticulous oral hygiene until Plaque Index and Gingival Index approached zero. The carious state of the bucco-gingival enamel areas, excluding molars, was evaluated using a dissection microscope. The cleaned and dried tooth surfaces were scored according to the Caries Index system. During a period of 23 days without oral hygiene 6 participants performed 9 daily mouthrinses with 10 ml of a 50% sucrose solution. At the termination of this period the sucrose group demonstrated a higher mean Caries Index and a greater number of new early lesions than the six control subjects. The mean Plaque Index scores were higher in the sucrose group, whereas the Gingival Index scores were similar for both groups. Smears of plaque showed no significant differences in the percentage distribution of various types of microorganisms. After 30 days of oral hygiene and daily mouthrinses with 0.2 % NaF, fair agreement was found between the Caries Index scores of the two groups. Similar observations were made after a second hygiene and fluoride period. The results demonstrate that it is possible to produce detectable carious alterations within 23 days by abolishment of oral hygiene and frequent sucrose additions and that these alterations are reversible.