5.6. Caries
5.6.1. Areas of dentinal caries
In Table 8, the areas of caries lesions were calculated only from the fissures, which have dentinal caries. Only the groups with the high-sucrose diet were included, because there were no dentinal caries lesions in the groups with the standard diet. The right and left side did not differ markedly and they are combined. Also there was no difference between the male and the female rats, thus their data are combined, too.
Table 8. Areas of dentinal caries lesions. Total numbers of the fissures examined (n) and percentages of the fissures with dentinal caries lesions. Minimum, maximum and mean of the lesion area in each group, given in square micrometers (calculated only from the fissures with lesion). The experimental groups are arranged according to the number and the mean size of the lesion.
| Molar | Group | Fissures | Lesions | Area | |||
|---|---|---|---|---|---|---|---|
| n | % | Min | Max | Mean | |||
| first | 5 (r-alk-suc) | 21 | 81 | 800 | 13330 | 4810 | |
| 1 (m-acid-suc) | 12 | 67 | 440 | 9240 | 3980 | ||
| 3 (m-alk-suc) | 18 | 11 | 490 | 5380 | 2940 | ||
| 7 (norm-suc) | 18 | 44 | 40 | 7080 | 3420 | ||
| second | 5 (r-alk-suc) | 22 | 91 | 640 | 9460 | 4580 | |
| 1 (m-acid-suc) | 12 | 50 | 680 | 8330 | 4630 | ||
| 3 (m-alk-suc) | 18 | 22 | 210 | 1730 | 1057 | ||
| 7 (norm-suc) | 18 | 56 | 930 | 12260 | 4470 | ||
| third | 5 (r-alk-suc) | 19 | 100 | 5510 | 39350 | 16900 | |
| 1 (m-acid-suc) | 9 | 100 | 3140 | 25060 | 14760 | ||
| 3 (m-alk-suc) | 18 | 78 | 1040 | 16830 | 7190 | ||
| 7 (norm-suc) | 15 | 87 | 2140 | 16560 | 6500 | ||
In the first molars, the carious lesions were smallest in groups 3 (metabolic alkalosis) and 7 (controls). In both of those groups, there were also the greatest number of fissures with no dentinal caries. In the groups 1 (metabolic acidosis) and 5 (respiratory alkalosis) the lesions were the largest and more numerous.
In the second molars, there were the least caries and fewest lesions in group 3 (metabolic alkalosis). Lesions were equally large in the groups 1, 5 and 7, and the most numerous in the group 5. For easier comparison, a box plot presentation is given in Fig. 13. In the figure, the right and left side are also combined and the fissures with no caries are included.
Figure 13. Areas of dentinal caries in the second molars of the rats in the groups 1, 3, 5 and 7. Extreme values are marked as circles and outline values as asterisks. For box plot presentation: see Fig. 11.
In the third molars, lesions were generally larger and more numerous than in the first and second molars. Lesions were smallest in the groups 3 and 7 and largest in the group 5 (not much difference between the groups 1 and 5). There was only a few teeth with no dentinal caries, most of them existed in the group 3 (metabolic alkalosis).
5.6.2. Caries scoring
Schiff reagent revealed same amounts of caries in the groups with the standard diet (groups 2, 4, 6, 8, 9, 10, 11 were compared to each other in pairs) (data not shown). In all those groups, less than half of the fissures were affected by enamel lesions only, the rest were intact.
The results of Schiff staining are given in Table 9. According to the dye penetration, each fissure was classified as healthy (N), enamel lesion only (A), initial dentinal lesion (T), more advanced dentinal lesion (B) or cavitation (C). Percentages of each of these categories are given separately.
Table 9. Results of Schiff staining of the caries lesions. Percentages are given of the fissures with no caries (N) and lesions of different depths (A, T, B, C). The groups are arranged according to Table 8.
| Molar | Group | n | N | A | T | B | C |
|---|---|---|---|---|---|---|---|
| first | 5 (r-alk-suc) | 66 | 1,5 | 25,8 | 15,2 | 40,8 | 16,7 |
| 1 (m-acid-suc) | 36 | 2,8 | 16,6 | 27,8 | 27,8 | 25,0 | |
| 3 (m-alk-suc) | 54 | 13,0 | 64,7 | 16,7 | 5,6 | 0,0 | |
| 7 (norm-suc) | 54 | 3,7 | 63,0 | 5,6 | 25,9 | 1,8 | |
| second | 5 (r-alk-suc) | 44 | 0,0 | 2,3 | 20,4 | 63,7 | 13,6 |
| 1 (m-acid-suc) | 24 | 0,0 | 16,7 | 16,7 | 50,0 | 16,6 | |
| 3 (m-alk-suc) | 36 | 25,0 | 66,6 | 5,6 | 2,8 | 0,0 | |
| 7 (norm-suc) | 36 | 5,6 | 44,4 | 25,0 | 22,2 | 2,8 | |
| third | 5 (r-alk-suc) | 22 | 0,0 | 22,7 | 18,2 | 45,5 | 13,6 |
| 1 (m-acid-suc) | 12 | 0,0 | 16,7 | 25,0 | 50,0 | 8,3 | |
| 3 (m-alk-suc) | 18 | 5,6 | 72,1 | 16,7 | 5,6 | 0,0 | |
| 7 (norm-suc) | 18 | 5,6 | 66,6 | 5,6 | 22,2 | 0,0 | |
| Abbreviations: n = number of fissures, N = no lesion, A = enamel lesion, T = initial dentinal lesion, B = advanced dentinal lesion, C = cavitation. | |||||||
Lesions were scored and the dentinal lesions (T, B and C) were combined for comparison of the groups. The results of this scoring (see: 4.7.4. Statistics) are presented in Table 10. The sides were combined.
Table 10. Minimum, median and maximum of the sum scores of the caries lesions in each group (Schiff staining). Healthy fissures (N) were scored as 0, enamel lesions (A) as 1 and dentinal lesions (T, B, C) as 7 to emphasize the difference between enamel and dentinal lesions. The groups arranged according to Tables 8 and 9.
| Molar | Group | n | Min | Md | Max |
|---|---|---|---|---|---|
| first | 5 (r-alk-suc) | 66 | 8 | 15 | 21 |
| 1 (m-acid-suc) | 36 | 8 | 21 | 21 | |
| 3 (m-alk-suc) | 54 | 1 | 3 | 21 | |
| 7 (norm-suc) | 54 | 3 | 9 | 15 | |
| second | 5 (r-alk-suc) | 44 | 8 | 14 | 14 |
| 1 (m-acid-suc) | 24 | 8 | 14 | 14 | |
| 3 (m-alk-suc) | 36 | 1 | 2 | 8 | |
| 7 (norm-suc) | 36 | 1 | 8 | 14 | |
| third | 5 (r-alk-suc) | 22 | 1 | 7 | 7 |
| 1 (m-acid-suc) | 12 | 1 | 7 | 7 | |
| 3 (m-alk-suc) | 18 | 0 | 1 | 7 | |
| 7 (norm-suc) | 18 | 0 | 1 | 7 | |
| Abbreviations: n = number of fissures, N = no lesion, A = enamel lesion, T = initial dentinal lesion, B = advanced dentinal lesion, C = cavitation. | |||||