Title: Alternative Sweeteners

288 Kato and Moskowitz
croorganisms such as S. mutans and is responsible for adherence of the organisms
to the tooth. Metabolism of sugars and starches by these microorganisms in the
mouth leads to the formation of acids that if in sufficient quantity, will erode
tooth enamel during prolonged contact. Oral bacteria do not metabolize polyols
such as sorbitol, mannitol, maltitol, and xylitol; therefore no acid production occurs
(10).
Laboratory assessment of cariogenic or acidogenic potential had been
somewhat problematic. Quick preliminary screening of various materials for
cariogenic potential had been accomplished with various bioassays, using microorganisms
(11) or laboratory animals (12). A rigorous test, now well accepted,
is plaque pH telemetry in human subjects (13–15). Telemetry refers to the continuous
electronic data-gathering process used in these experiments. In these
tests, an indwelling pH electrode is secured in a denture appliance and implanted
onto a tooth, replacing an existing appliance. Several days after sufficient plaque
has built up on the appliance, the test subject is given a food and the pH
is monitored as a function of time. If acid formation does not reach below pH
5.7 in 30 minutes, the food may be certified as safe for teeth (‘‘zahnschonend’’
by the Swiss authorities). Demineralization of tooth enamel definitely occurs below
pH 5.5; between 5.5 and 5.7 is a transition range where some demineralization
may begin. The advantage of this in vivo experimental approach over other
in vitro assay methods is that it takes into account salivary flow, the buffering
capacity of saliva, and the removal of dissolved sugars from the mouth by swallowing.
More recently, however, another simplified in vitro test has been developed
that claims results comparable to that of the pH telemetry method (16). For a
comprehensive discussion of cariogenicity in foods, the reader is referred to a
special issue of the Journal of Dental Research, December 1986 (pp. 1473–
1543), that is based on the Scientific Consensus Conference on Methods for Assessment
of the Cariogenic Potential of Foods that was held at the University of
Texas Dental School, San Antonio, November 17–21, 1985. Among the many
Table 2 Plaque pH Minima After
Rinsing with Test Solutions
Product pH minimum
Crystalline maltitol 6.4 0.4
Sorbitol 6.5 0.4
Sucrose 5.5 0.5
Source: Adapted from Ref. 21.