Archs oral Bm/. Vol. 37, No. 8. pp. 63_%76. Printed in Great Britain. All rights rescued
1992 Copyright
SHORT
0003-9969 91 55.00 + 0.00 % 1992 Pergamon Press Lrd
COMMUNICATION
THE THICKNESS OF THE SOUND AND PERIODONTALLY DISEASED HUMAN CEMENTUM S. KATO,’
H.
NAKAGAKI,’
H. KUSISAKI,’ N. SUGIHARA,~T. NOGUCHI,’ F. ITO,’ I. YOSHIOKA, J. A. WEATHERELL’ and C. ROBINSON’
‘Department of Preventive Dentistry and Dental Public Health, ‘Department of Periodontology, School of Dentistry, Aichi-Gakuin University, l-100 Kusumoto-cho, Chikusa-ku. Nagoya 464, ‘Department of Dentistry, Meitetsu Hospital, 3-45 Xlatsumae-cho, Nishi-ku, Nagoya 351, ‘Division of General Education, Aichi-Gakuin University. 12 Araike, Iwasaki, Nisshin-cho, Aichi-gun, Aichi-ken 470-01, Japan and SDepartment of Oral Biology, School of Dentistry, University of Leeds, Clarendon Way, Leeds LS2 9LU, U.K. (Received I-1 March 1991: accepted 3 March 1992) Summary-Cementum of teeth previously analysed for fluoride was re-examined in order to determine whether or not periodontal disease had affected the thickness of the tissue. In the periodontally diseased teeth the cementum was thinner than normal in the middle region of the root. The apical cementum. however, was significantly thicker in periodontally diseased than in the sound teeth of subjects over 60 yr old. This may account for the higher total fluoride levels previously reported in the apical cementum of these same teeth.
Key words: cementurn, periodontal disease, fluoride.
Nakagaki et al. (1985) have shown the increase in thickness of cementum with age. Zander and Hiirzeler (1958) found a positive linear relationship between the thickness of cementum and the age of sound teeth; in periodontally diseased teeth, on the other hand, the cementum ceased to increase in thickness with age. We recently examined the fluoride distribution in cementum from the middle and apical regions of the root in sound and periodontally diseased teeth (Sugihara et al., 1991). In the periodontally diseased teeth the total fluoride content was greater and increased more rapidly with age in the apical than in the middle region. At the apical site, the
fluoride increase with age was greater in periodontally diseased than in sound teeth. As the fluoride content of the cementum might be influenced by a change in the tissue’s thickness, we now decided to make a detailed examination of the thickness of cementum in the teeth used in the earlier study. The specimens were described in detail before: in brief, the material consisted of 10 periodontally diseased human lower incisors, extracted from 10 patients, aged 32-72 yr old and residents of Nagoya, Japan (F concentration of drinking water ~0.1 parts/106) and 10 healthy lower incisors taken, postmortem, from subjects aged 29-82 yr old, former
Table I. Cementum thickness of human lower incisors (u m)
Middle
5
P Apical
S
P Middle/apical (M/A)
S
P
Less than 59 yr old (mean) + (SE) (N)
Over 60 yr old (mean) F (SE) IN)
113.8 * 19.7 (5) _ 108.0 k 12.8 (5) 1
160.0 + 7.41 (5) _ 149.0 + 4.85 (5) 3
139.0 f 17.8 (5) 150.0 k 15.0 (5) 0.82+0.11 (5) 0.77 & 0.14 (5)
1 1 _
_
191.0 + 18.1 (5) 237.4 k 9.68 (5)
1 l
0.87 i 0.09 (5) I) 0.63 & 0.03 (5) I
Cementum was generally thinner in the middle region of the root of the periodontally diseased teeth than in the sound teeth although the difference was not statistically significant. In subjects over 60 yr old the apical cementum was significantly thicker in the periodontally diseased than in the sound teeth. There was significant difference in the thickness of sound versus periodontally involved cementum in the younger age group. s, Sound cementum; p. periodontally diseased cementum; IV, number of teeth examined; -: p > 0.05; *: p < 0.05. 675
S. KATO ef al.
676
L
S
< 60 years old
2 60 years old
_
middle cementurn
_ _^
t < 60 years old apical cementum
60
P
years old
Fig. 1. Effect of periodontal disease on the thickness of middle and apical region of the human cementum. s, Sound cementum; p, periodontally diseased cementum. *p < 0.05
residents of the same city. All the teeth were clinically caries free. In the periodontally diseased teeth, the cementum from the middle site had been situated within the periodontal pocket and, being above the epithelial junction, was probably accessible to the oral environment. The apical regions of the periodontally diseased teeth, however, were not exposed to the oral environment. In the case of the sound postmortem teeth, neither the middle nor the apical sites had been exposed to the oral environment. A mesiodistal section about 300pm thick was prepared parallel to the longitudinal axis of each tooth. One of these was taken from a site midway between the root apex and the cervical margin; the other was from a site 3-5 mm from the root apex. Layers of cementum were then removed from the specimens using an abrasive micro-sampling technique (Weatherell et al., 1985). The difference in the thickness between sound and periodontally diseased cementum was evaluated statistically by the Student r-test (two-tailed) (Sokol and Rohlf, 1981). As reported by Hiirzeler and Zander (1959) the cementum in the middle regions of the root tended to be thinner in the periodontally diseased than in the sound teeth. Perhaps no further cementum apposition would be expected when the root surface was within a pocket. However, we also found differences in the apical cementum, this being significantly thicker in the peridontally diseased teeth (Table 1, Fig. 1). The explanation for this must be speculative but, with loss of periodontal attachment in a
periodontally diseased tooth, the remainder of the root will be subjected to greater strain. This, in turn, may induce cementum apposition, and could account for the increased thickness and the previously reported higher total fluoride content (Sugihara ef al., 1991) of the apical cementum in these same teeth. Recently Dastmalchi et al. (1990) have considered the importance of functional stimulation to the thickness of cementum.
REFERENCES Dastmalchi R., Poison A., Bouwsma 0. and Proskin H. (1990) Cementum thickness and mesial drift. J. clin. Periodonr. 17, 709-7 13.
Htirzeler B. and Zander H. A. (1959) Cementum apposition in periodontally diseased teeth. Hek. odonf. Acta 3, 1-3.
Nakagaki H., Weatherell J. A., Storong M. and Robinson C. (1985) Distribution of fluoride in human cementum. Arcks oral Biol. 30, 101-104.
Sokal R. R. and Rohlf F. J. (1981) Biometry, 2nd edn, pp. 128-178. Freeman, New York. Sugihara N., Nakagaki H., Kunisaki H., Ito F., Noguchi T., Weatherell J. A. and Robinson C. (1991) Distribution of fluoride in sound and periodontally diseased human cementum. Archs oral Biol. 36, 383-387. Weatherell J. A., Robinson C., Storong M. and Nakagaki H. (1985) Micro-sampling by abrasion. Caries Res. 19, 97-102. Zander H. A. and Hiirzeler B. (1958) Continuous cementum
apposition. J. dent. Res. 37, 1035-1044.
1992 Copyright
SHORT
0003-9969 91 55.00 + 0.00 % 1992 Pergamon Press Lrd
COMMUNICATION
THE THICKNESS OF THE SOUND AND PERIODONTALLY DISEASED HUMAN CEMENTUM S. KATO,’
H.
NAKAGAKI,’
H. KUSISAKI,’ N. SUGIHARA,~T. NOGUCHI,’ F. ITO,’ I. YOSHIOKA, J. A. WEATHERELL’ and C. ROBINSON’
‘Department of Preventive Dentistry and Dental Public Health, ‘Department of Periodontology, School of Dentistry, Aichi-Gakuin University, l-100 Kusumoto-cho, Chikusa-ku. Nagoya 464, ‘Department of Dentistry, Meitetsu Hospital, 3-45 Xlatsumae-cho, Nishi-ku, Nagoya 351, ‘Division of General Education, Aichi-Gakuin University. 12 Araike, Iwasaki, Nisshin-cho, Aichi-gun, Aichi-ken 470-01, Japan and SDepartment of Oral Biology, School of Dentistry, University of Leeds, Clarendon Way, Leeds LS2 9LU, U.K. (Received I-1 March 1991: accepted 3 March 1992) Summary-Cementum of teeth previously analysed for fluoride was re-examined in order to determine whether or not periodontal disease had affected the thickness of the tissue. In the periodontally diseased teeth the cementum was thinner than normal in the middle region of the root. The apical cementum. however, was significantly thicker in periodontally diseased than in the sound teeth of subjects over 60 yr old. This may account for the higher total fluoride levels previously reported in the apical cementum of these same teeth.
Key words: cementurn, periodontal disease, fluoride.
Nakagaki et al. (1985) have shown the increase in thickness of cementum with age. Zander and Hiirzeler (1958) found a positive linear relationship between the thickness of cementum and the age of sound teeth; in periodontally diseased teeth, on the other hand, the cementum ceased to increase in thickness with age. We recently examined the fluoride distribution in cementum from the middle and apical regions of the root in sound and periodontally diseased teeth (Sugihara et al., 1991). In the periodontally diseased teeth the total fluoride content was greater and increased more rapidly with age in the apical than in the middle region. At the apical site, the
fluoride increase with age was greater in periodontally diseased than in sound teeth. As the fluoride content of the cementum might be influenced by a change in the tissue’s thickness, we now decided to make a detailed examination of the thickness of cementum in the teeth used in the earlier study. The specimens were described in detail before: in brief, the material consisted of 10 periodontally diseased human lower incisors, extracted from 10 patients, aged 32-72 yr old and residents of Nagoya, Japan (F concentration of drinking water ~0.1 parts/106) and 10 healthy lower incisors taken, postmortem, from subjects aged 29-82 yr old, former
Table I. Cementum thickness of human lower incisors (u m)
Middle
5
P Apical
S
P Middle/apical (M/A)
S
P
Less than 59 yr old (mean) + (SE) (N)
Over 60 yr old (mean) F (SE) IN)
113.8 * 19.7 (5) _ 108.0 k 12.8 (5) 1
160.0 + 7.41 (5) _ 149.0 + 4.85 (5) 3
139.0 f 17.8 (5) 150.0 k 15.0 (5) 0.82+0.11 (5) 0.77 & 0.14 (5)
1 1 _
_
191.0 + 18.1 (5) 237.4 k 9.68 (5)
1 l
0.87 i 0.09 (5) I) 0.63 & 0.03 (5) I
Cementum was generally thinner in the middle region of the root of the periodontally diseased teeth than in the sound teeth although the difference was not statistically significant. In subjects over 60 yr old the apical cementum was significantly thicker in the periodontally diseased than in the sound teeth. There was significant difference in the thickness of sound versus periodontally involved cementum in the younger age group. s, Sound cementum; p. periodontally diseased cementum; IV, number of teeth examined; -: p > 0.05; *: p < 0.05. 675
S. KATO ef al.
676
L
S
< 60 years old
2 60 years old
_
middle cementurn
_ _^
t < 60 years old apical cementum
60
P
years old
Fig. 1. Effect of periodontal disease on the thickness of middle and apical region of the human cementum. s, Sound cementum; p, periodontally diseased cementum. *p < 0.05
residents of the same city. All the teeth were clinically caries free. In the periodontally diseased teeth, the cementum from the middle site had been situated within the periodontal pocket and, being above the epithelial junction, was probably accessible to the oral environment. The apical regions of the periodontally diseased teeth, however, were not exposed to the oral environment. In the case of the sound postmortem teeth, neither the middle nor the apical sites had been exposed to the oral environment. A mesiodistal section about 300pm thick was prepared parallel to the longitudinal axis of each tooth. One of these was taken from a site midway between the root apex and the cervical margin; the other was from a site 3-5 mm from the root apex. Layers of cementum were then removed from the specimens using an abrasive micro-sampling technique (Weatherell et al., 1985). The difference in the thickness between sound and periodontally diseased cementum was evaluated statistically by the Student r-test (two-tailed) (Sokol and Rohlf, 1981). As reported by Hiirzeler and Zander (1959) the cementum in the middle regions of the root tended to be thinner in the periodontally diseased than in the sound teeth. Perhaps no further cementum apposition would be expected when the root surface was within a pocket. However, we also found differences in the apical cementum, this being significantly thicker in the peridontally diseased teeth (Table 1, Fig. 1). The explanation for this must be speculative but, with loss of periodontal attachment in a
periodontally diseased tooth, the remainder of the root will be subjected to greater strain. This, in turn, may induce cementum apposition, and could account for the increased thickness and the previously reported higher total fluoride content (Sugihara ef al., 1991) of the apical cementum in these same teeth. Recently Dastmalchi et al. (1990) have considered the importance of functional stimulation to the thickness of cementum.
REFERENCES Dastmalchi R., Poison A., Bouwsma 0. and Proskin H. (1990) Cementum thickness and mesial drift. J. clin. Periodonr. 17, 709-7 13.
Htirzeler B. and Zander H. A. (1959) Cementum apposition in periodontally diseased teeth. Hek. odonf. Acta 3, 1-3.
Nakagaki H., Weatherell J. A., Storong M. and Robinson C. (1985) Distribution of fluoride in human cementum. Arcks oral Biol. 30, 101-104.
Sokal R. R. and Rohlf F. J. (1981) Biometry, 2nd edn, pp. 128-178. Freeman, New York. Sugihara N., Nakagaki H., Kunisaki H., Ito F., Noguchi T., Weatherell J. A. and Robinson C. (1991) Distribution of fluoride in sound and periodontally diseased human cementum. Archs oral Biol. 36, 383-387. Weatherell J. A., Robinson C., Storong M. and Nakagaki H. (1985) Micro-sampling by abrasion. Caries Res. 19, 97-102. Zander H. A. and Hiirzeler B. (1958) Continuous cementum
apposition. J. dent. Res. 37, 1035-1044.
