Table 1: Summary of human caries studies on xylitol that in part have constituted the justifications for public endorsements of xylitol. The percent-reductions are in comparison with a control group that received a normal diet, fluoride treatment, or sucrose products. Nondietary (dentifrice) studies and programs on multiple preventive measures that included the use of xylitol are also shown. CH = Chlorhexidine.

Study locationProduct(s) testedDuration (years)Dose (g/day)Caries reduction (%). Comments. (References).

FinlandFull diet 267>85. Compared with sucrose diet [13, 65]. Mostly adults.

FinlandChewing gum 1 6.7>82. Compared with sugar gum. 1/10 of the above dosage [13, 65]. Young adults.

Soviet UnionCandies 230Up to 73. Compared with sucrose candies [66].

French PolynesiaChewing gum 3About 2058–62. Compared with normal diet [67].

HungaryGum, candies, dentifrice 2-314–2037–45. Compared with fluoride [68, 69].

CanadaChewing gum 1-21.0–3.952. [70].

FinlandChewing gum 27–1030–57. All subjects (no-gum as control)(a). [71].

FinlandChewing gum 37–1059–84. High-risk subjects(a). [71].

Costa RicaDentifrice + NaF 3Twice/dayUp to 12.3. 10% xylitol in the product. [44].

Costa RicaDentifrice + Na2FPO3 3Twice/dayUp to 10. 10% xylitol in the product. [45].

BelizeChewing gum 3.3<10.7Up to 73. Permanent teeth(b). [61].

BelizeChewing gum 2<10.7Up to 63. Deciduous teeth(c). [72].

USAGum, pastilles 1.88.580. Supragingival root surface caries. Elderly subjects [73].

EstoniaGum, pastilles 2-3550–60. Used on school days(d). [51]. Pastille as effective as gum.

FinlandChewing gum (by mothers)ca. 1.75670 (in children). NaF and CH as control [74].

LithuaniaChewing gum32.9521–36. [35]. Rectification of initial results [36](e).

SwedenChewing gum (by mothers)12“Significant” or 40% (in children). [75, 76](f).

KuwaitHard caramels1.52.350. Läkerol-type hard candies were used [57](g).

Finland“Slow-release pacifier”1159 mgNo new dentinal lesions in infants [46]. A mixture of xylitol, sorbitol, and NaF was tested. The pacifier features a pocket for the sweetened tablet.

FinlandMultiple measuresAbout 3.44.6Counselling and the use of fluoride- and xylitol products reduced caries ( ) compared with basic prevention [77](i).

effects (after up to 5-year use) have been reported [7880]. An independent analysis showed that the total number of new restored surfaces was 4.0 per child in the xylitol group and 9.3 in the controls during the decade after the onset of the trial. Participation in the xylitol gum trial thus resulted in significant reduction in the number of first restorations and hence in costs during the subsequent decade [81].
(b)16-month use of xylitol gum following the 3.3-year use of sucrose gum reduced caries significantly [82]. “<10.7” indicates the maximum calculated, supervised use (at school) per day and subject.
(c)Two-year use of xylitol gum remarkably protected erupting permanent teeth against caries, that is, long-term effects were involved [83].
(d)Saliva stimulants were given only on school days (about 200 per school year). Gums were as effective as pastilles (hard candies of the “Läkerol-type”).
(e)The original authors failed to recognize that, in their study, xylitol gum was the only gum that lowered the DMFS increment compared with the no-gum group after 3 years. “To still observe a significant caries-lowering effect of xylitol with such a small dosage is quite remarkable”. The faulty conclusions were rectified by Hayes [36].
(f)In one literature source, the authors reported an 80% reduction between “test and control”. Also, when the children were 18 months old, the authors reported that “maternal consumption of xylitol- and CH/xylitol-containing chewing gums significantly reduced the mother-child transmission of salivary mutans streptococci”. This study actually compared a gum with high xylitol content with gums with lower xylitol content, supplemented with either CH or NaF.
(g)Xylitol hard candies were given only on school days (one piece of candy at a time, three times a day).
(h)The pacifier features a pocket from which the saliva stimulants dissolve.
(i)The Läkerol Dents brand (Leaf). The products were given to the subjects with instructions “to be used according to directions” (i.e., two pieces of candy three times a day). The calculated maximum consumption level of xylitol was about 4.6 g/day.