Archs oral Bid. Vol.36, No. 5, pp. 383-381, 1991 Printed in Great Britain. All rights reserved

DISTRIBUTION PERIODONTALLY

0003-9969/91 $3.00 + 0.00 Copyright 0 1991 Pergamon Press plc

OF FLUORIDE IN SOUND AND DISEASED HUMAN CEMENTUM

N. SUGIHARA,’H. NAKAGAKI,~H. KIJNISAKI,~F. 1~0,~ T. NOGUCHI,’ J. A. WEATHERELL~ and C. ROBINK& ’ Department of Periodontology, School of Dentistry, Aichi-Gakuin University, 2- 11 Suemori-dori, Chikusa-ku, Nagoya 464, 2Department of Preventive Dentistry and Dental Public Health, School of Dentistry, Aichi-Gakuin University, l-100 Kusumoto-cho, Chikusa-ku, Nagoya 464, ‘Department of Dentistry, Meitetsu Hospital, 3-45 Matsumae-cho, Nishi-ku, Nagoya 451, Japan and ‘Department of Oral Biology, School of Dentistry, University of Leeds, Clarendon Way, Leeds LS2 9LU, U.K. (Received 14 August 1990; accepted 14 November 1990) Summary-Fluoride distribution was investigated by an abrasive micro-sampling technique. The fluoride concentration increased with age in both sound and diseased cementum. In sound teeth, the fluoride profiles (distribution of fluoride from the surface to interior) of the middle and apical cementurn were similar. In the diseased cementum the profile of the middle region tended to be more variable than that of the apical cementum, suggesting a possible effect of the oral environment on the fluoride profile at this site. Key words: fluoride, cementum, periodontal disease.

INTRODUCTION

Nakagaki et al. (1985) and Murakami et al. (1987) showed that profiles of fluoride (F) in human cementurn were characteristic of the individual. They were similar in all regions of the root and often appeared in several teeth from the same mouth. Nakagaki et al. (1988) showed that the individual profiles also reflected the histological pattern, especially the distribution of cellular or acellular cementum. Fluoride concentrations were also related to the precise site in the tooth from which the specimen was taken. There was a marked increase in the F content of coronal dentine with age, at least until about 50 yr. However, the F concentration of root dentine and cementum continued to increase throughout the life of the tooth (Nakagaki et al. 1987). Little information is available about the extent to which the characteristic pathological changes in periodontitis are accompanied by changes in the chemical composition of the supporting dental hard tissues. The periodontal changes might influence their mineral metabolism; substances present in the oral environment, such as fluoride, might penetrate the periodontal pocket and be absorbed by the underlying cementum and dentine. We have now sought to investigate whether the fluoride profiles in human cementum are changed when a tooth becomes periodontally diseased. MATERIALS AND METHODS

Subjects and tooth specimens

Ten periodontally diseased human lower incisors extracted from 10 patients, aged from 32 to 72 yr and resident in Nagoya., Japan (F concentration of drinking water 90.1 parts/106) were compared with 10 sound human lower incisors obtained post mortem

from 10 subjects, aged from 29 to 82 yr, in same city. The teeth were clinically caries-free. Cementurn specimens and determination of phosphorus and filroride

A mesio-distal section about 300 pm thick was cut through the centre, in the longitudinal axis of each tooth. Two specimens were removed from the section, one from a site midway between the root apex and the cervical margin, and the other from a site 3-5 mm from the root apex. Layers of the cementum were then removed from the specimens by an abrasive microsampling technique and the powdered samples were then dissolved in about 15 ~1 of acid, as described by Weatherell et al. (1985). The phosphorus (P) concentration was determined on 4 ~1 of this acid solution by the calorimetric procedure of Chen, Toribara and Warner (1956), and the F concentration on 2~1 by the F electrode, using the micro-technique described by Hallsworth, Weatherell and Deutsch (1976). The concentrations of F in the tissue were calculated from the F : P ratios obtained. The results have been expressed as parts/lo6 per weight of cementum, calculated from the P estimation, making the assumption that the P concentration of cementum was 12.2%, in accordance with data provided by Lazzari (1968). The concentrations of F and its distribution profile were determined and the data also expressed in terms of total F content (total F), represented by the area beneath the distribution curve (mm*), and average F concentration (average F) (parts/106), calculated as previously described (Nakagaki et al. 1985, 1987). The relationship between fluoride and age in the middle and apical regions of both sound and periodontally diseased cementum was analysed. Correlation coefficients were evaluated using the t-value, as described by Sokal and Rohlf (1981). 383

N. SUGEIARA

384

periodontally diseased subjects were more variable, especially at the middle site.

RESULTS Projiles of F distribution from sound and periodontally diseased cementum

Total F, average F and maximum F concentration

These concentrations, calculated from the above profiles, are shown in Table 1, together with the corresponding ratios of middle site : apical site (M/A). The total (Fig. 2), average (Fig. 3) and maximum fluoride concentrations (Fig. 4) increased with age

Typical profiles are plotted in Fig. 1. F concentrations generally increased with age in both the middle and the apical sites. The F profiles from the middle and apical sites in sound teeth tended to be similar in form. The F profiles in teeth from 3

Sound group

et al.

~rJarts/106t x103 3

CDJ

F

F 2

2

1

1

Middle site

1

v7

CDJ

I!bi!L 1

(parts /IO”

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2

Apical site

1

par,

b-

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Apical site 1

1

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Fig. 1. Four typical profiles of F distribution from sound and periodontally diseased cementum are plotted. The thin vertical line in the profiles shows the cementum-dentine junction (CDJ).

Distribution of fluoride in sound and periodontally diseased human ccmentum

385

Table 1. The values for the total F, average F and maximum F concentrations of the cementum calculated from the figures and ratios of the middle site to the apical site of cementum Total F (mm21 Av. F (parts/106) Sound cementum Periodontally diseased cementum Sound cementum Periodontally diseased cementum

1509 128 1631 136

2140 541 3379 517

Apical site 889 79 1203 236

1372 176 1466 191

2035 286 2274 304

Ratio of middle to apical 0.919 1.106 0.095 0.079 0.885 1.204 0.123 0.085

Sound cementum Periodontally diseased cementum

both in the middle and apical site. All three measures of concentration increased markedly with the age in the periodontally diseased cementum, particularly at the apical site. In the sound cementum, on the other hand, concentrations increased much more gradually if at all. The correlation coefficients in periodontally diseased cementum were higher than those in sound cementum (Figs 2, 3 and 4). After the age of 50, total F, average F and maximum fluoride concentrations all tended to be higher in periodontally diseased cementum than in the sound cementum.

3000

Totol -

F in the

2ooo

-o-

Perio

--.--

Swnd

middle

site

of the

1.053 0.231 1.653 0.231

Ratios of F concentration between middle and apical cementum (M/A ratio)

In sound cementum, the M/A ratios in terms of total F, average F or maximum F concentration did not change with age (Fig. 5). In periodontally diseased cementum, however, these ratios decreased with age. All ratios in periodontally diseased cementum tended to decrease with age, whereas those in sound cementum were higher below the age of about 50 and lower above the age of about 50.

rOOt 3000

r

Ave.

F in the

-

middle

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Age Totol

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I 40

F in the

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Age

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of the

r

3000

0

root

Ave.

F

in the

(yr) apical

/

L-l-,“/; 20

40

I 60

I 80

Age (yr)

Fig. 2. The values for the total F concentration (total F) represented by the area beneath the distribution curve in sound and periodontally diseased cementum. Total F after the age of 50 years is higher in the diseased than in the sound cementum.

Age (yr) Fig. 3. The values for the average (ave.) F concentration (average F, parts/106) formed by dividing the sum of F concentration by the numbers of layers determined. The average F after the age of 50 yr is higher in the diseased than in the sound cementum.

N. SUGIIURA et al.

386 F

Max. 6000

In the

mlddle

site

of

the

mot

of the

root

This was true of both sound and periodontally diseased cementurn. The similar F profiles at the middle and apical sites of sound cementurn probably reflect F uptake from the surrounding tissue fluids, as previously suggested (Nakagaki et al., 1985, 1987). This view was further supported by the observation that the ratio of fluoride concentrations for the middle and apical sites did not change with regard to total F, average F or maximum F. In periodontally diseased cementum, however, fluoride concentrations at the middle site were more variable than at the apical site, both in terms of the F profiles and when the data were expressed as any of the three indices. The difference in thickness between middle and apical cementum was also greater in the periodontally diseased teeth than in the sound teeth; this agrees with the observation of Hiirzler and Zander (1959). Apposition of cementum may have decreased or stopped as a result of the loss of periodontal attachment. At the apical site, on the other hand, the apposition of cementum continued throughout the life of tooth (Nakagaki et al., 1987). At this site, cementum formation might be stimulated in response to a loss of apical supporting tissue, resulting in a thicker layer. The mechanism of such stimulation could be a direct response to increased apical movement, consequent upon the loss of periodontal support. Earlier studies (Selvig and Selvig, 1962; Nakata, Stepnick and Zipkin, 1972; Wirthlin et al., 1979) have shown that the mineral content of cementum may change with age as well as with involvement in periodontal disease by as much as 10%. This source of variation would not significantly affect our findings, as the observed variations in F content were in the order of several hundred per cent. In our next series of experiments, however, we would like to look at the matter in detail. The occasionally high concentrations of fluoride and the more variable fluoride profiles in the cementum from the middle site, on the other hand, were probably due to fluoride migrating from the oral environment into the periodontal pocket. As we do not have information about the periodontal pocket depth, we cannot comment in any more detail about the possible influence this might have had upon fluoride concentrations in the cementum, for which a more detailed study is required.

0

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I 40 Age

8000

F

.

Q

in the

.

I 60

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Age (yr)

Fig. 4. The maximum F concentration (max. F) chosen from

the highest concentration in each specimen. The maximum F after the age of 50 yr tended to be higher in the diseased than in the sound cementurn.

DISCUSSION

The sound cementum obtained post mortem, from both the middle and the apical sites on each root had not been exposed to the oral environment. In the periodontally diseased teeth, the cementum taken from the middle site had been close to the bottom of the periodontal pocket and was therefore exposed above the epithelial attachment. The apical sites of the periodontally diseased teeth, however, were still unexposed. Unfortunately, precise information about the clinical depth of the pocket and attachment level was not available. As previously reported (Nakagaki et al., 1985, 1987), fluoride concentrations increased with age.

M/A

3r

in total

*:p

2-

0

r--0.77

20

F

3r

M/A

ave. F

M/A

in max. F

3r

< 0.01

**

in _

Perio

--.--

Sound

2-

40

60

60

0

I 20

I 40

I 60

I 60

0

I 20

I 40

I 60

I 60

Fig. 5. The ratio of the fluoride content of middle cementum to that of the apical (M/A) in terms of total F, average F, or maximum F concentration.

Distribution of fluoride in sound and periodontally diseased human cementum REFERENCES Chen P. S., Toribara T. Y. and Warner H. (1956) Microdetermination ofphosphorus. Analyf. Chem. %I,17561758. Hallsworth A. S., Weatherell J. A. and Deutsch D. (1976) Determination of subnanogram amounts of fluoride with the fluoride electrode. Analyt. Chem. 49, 1960-1964. Hiirzeler B. and Zander H. A. (1959) Cementum apposition in periodontally diseased teeth. Helu. Odont. Acra 3, l-3. Lazzari E. P. (1968) Chemical composition of teeth. In: Denfal Biochemistry (Edited by Lazzari E. P.) pp. l-8. Lea & Febiger, Philadelphia, Penn. Murakami T., Nakagaki H., Sakakibara Y., Weatherell J. A., Robinson C. (1987) The distribution pattern of fluoride concentration in human cementurn. Archs oral Biol. 32, 567-571.

Nakagaki H., Weatherell J. A., Strong M. and Robinson C. (1985) Distribution of fluoride in human cementurn. Archs oral Biol. 30, 101-104. Nakagaki H., Koyama Y., Sakakibara Y., Weatherell J. A. and Robinson C. (1987) Distribution of fluoride across

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human dental enamel, dentine and cementum. Archs oral Biol. 32, 651654.

Nakagaki H., Kawai K., Murakami T., Sakakibara Y., Ohno N., Weatherell J. A. and Robinson C. (1988) Fluoride distribution and histological structure of human cementum. Archs oral Biol. 33, 257-264. Nakata T. M., Stepnick R. J. and Zipkin I. (1972) Chemistry of human dental cementum: the effect of age and fluoride exposure on the concentration of ash, fluoride calcium, phosphor0 and magnesium. .I. Periodont. 43, 15-124.

Selvig K. A. and Selvig S. K. (1962) Mineral content of human and seal cementum. J. dent. Rex 41, 624632. Sokal R. R. and Rohlf F. J. (1981) Biometry, 2nd edn., Chap. 15, pp. 561-616. Freeman, New York. Weatherell J. A., Robinson C., Strong M and Nakagaki H. (1985) Micro-sampling by abrasion. Curies Res. 19, 97-102. Wirthlin M. R., Pederson E. D., Hancock E. B., Lamberts B. L. and Leonard E. P. (1979) The hypermineralization of diseased root surfaces. J. Periodont. 50, 125-127.

Distribution of fluoride in sound and periodontally diseased human cementum.

Fluoride distribution was investigated by an abrasive micro-sampling technique. The fluoride concentration increased with age in both sound and diseas...
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