Surface Caries Research Articles

Relationship of Streptococcus mutans and lactobacilli to incipient smooth surface dental caries in man

Small samples of plaque were obtained from a number of incipient (white spot) caries lesions on buccal tooth surfaces or cavitated caries lesions on buccal and approximal surfaces. The clinically-sound tooth surface surrounding each lesion was similarly sampled. The proportions of Streptococcus mutans in samples from carious areas were significantly higher than those from the adjacent sound surface areas. Lactobacilli were not detected in samples from white spots and were recovered from only a few samples from the surrounding sound tooth surface. S. mutans preferentially colonized the gingival area of buccal tooth surfaces. The heterogeneity of dental plaque with respect to the concentrations of S. mutans was striking; 100-fold differences in concentration between samples taken from a single lesion were frequent. The recovery of S. mutans from plaque cultured on mitis-salivarius agar, supplemented with 15 per cent sucrose and 0.2 units per ml of bacitracin (MSB agar), which is selective for this organism, was generally lower than with mitis-salivarius agar without tellurite. Its recovery on MSB agar with and without tellurite was similar.

Streptomyces globisporus 由来の溶菌酵素による洗口が人の乳歯齲蝕抑制に及ぼす効果

It has been reported from our laboratory that a bacteriolytic enzyme derived from Streptomyces globisporus strain 1829 possessed the lytic action against strains of Streptococcus mutans, cariogenic Lactobacillus casei ATCC 4646 and Actinomyces viscosus strain T6. In the scanning electron microscopic studies, the cariogenic bacteria in the artificial dental plaque formed on the enamel surface in vitro were lyzed by the enzyme in situ. Similarly, the microorganisms in the naturally forming plaque on the tooth surface in vivo was also apparently affected by this enzyme. Furthermore, it was observed that the caries development in a group of hamsters, which were kept in the cariogenic diet #2000 containing the bacteriolytic enzyme, was signifficantly inhibited as compared with a group of hamsters which received the same diet without the enzyme. The effectiveness, however, of the enzyme on caries prevention in humans is not obscure. The purpose of the present experiment was to study the effect of the bacteriolytic enzyme on the inhibition of dental caries of children in a nursery school. One hundred sixteen children between 2 and 4 year age were divided into two groups, an experimental and control group. They received seven ml of mouthwash containing 3mg (3, 000 units) of the enzyme twice a day for washing in one minute their mouth after between meals. The procedure was continued for 18 months except holidays. In the control group, the conditions was the same as the experimental group except that the enzyme was replaced by 3mg of lactose. Every 3 months, the carious lesions were recorded by oral inspection. The increment of dmft during 12 months was 1.6 in experimental group (Gr.1) and 3.3 in control group (Gr.2). These figures led the percentage of inhibition at 51.5. The increment of dmft during 18 months was 2.2 in Gr.1 and 3.8 in Gr.2, and the percentage of dental caries inhibition at this stage was 42.1. Concerning the dmfs index, an increment of the value during 12 months was 4.8 in Gr.1 and 9.5 in Gr.2 with the percentage of inhibition was 49.5. The index at 18 months was 6.9 in Gr.1 and 11.1 in Gr.2, which indicates 37.9% of inhibition. The increment of pit and fissure caries surfaces during 12 months was 0.9 in Gr.1 and 1.7 in Gr.2, indicating 47.1% of inhibition. Similarly, an increment of the surfaces during 18 months was 1.1 in Gr.1 and 2.0 in Gr.2 with the percentage of inhibition was 45.0. In the case of smooth surface caries, the increment was 3.9 in Gr.1 and 7.8 in Gr.2 during 12 months with the percentage of inhibition was 50.0. The values at 18 months were 5.7 and 9.1 in respective groups with the percentage of inhibition was 37.4. The increment of expansion of carious lesions was 10.2 in Gr.1 and 18.4 in Gr.2 during 12 months, which indicates 44.6% of inhibition. The values at 18 months were 13.2 in Gr.1 and 24.1 in Gr.2 indicating 45.2% of inhibition. These results strongly suggested that a mouthwash containing the bacteriolytic enzyme from S. globisporus is a useful procedure for the dental caries prevention of deciduous teeth, and also applicable on the numerous groups of children.

Reduction of Dental Decay in Rampant Caries Individuals Following Short-Term Kanamycin Treatment

A week of kanamycin gel treatment before and after the placement of dental restorations, compared to a placebo gel treatment, significantly reduced the levels of cultivable bacteria, S mutans and S sanguis, in the plaque samples collected immediately after the completion of the gel treatments, and was associated with a 46% reduction in new carious surfaces in the 14- to 37-month period following the gel treatment.

Caries frequency in children with controlled diabetes.

The frequency of caries was assessed in 33 diabetic children in whom the diabetes required insulin and dietary restriction and had been diagnosed before eruption of the permanent teeth. The frequency of caries and the number of erupted teeth were obtained from the dental records of the school dental service. Age- and sex-matched non-diabetic classmates served as controls. The mean number of DFS at the last dental examination of the diabetic children was 13.4, compared with 20.5 in the controls. The difference was largest in 12- to 14-year-old children, particularly in the premolar region, where the mean number of carious and filled surfaces in the diabetics was 2.6 compared with 5.9 in the controls. In all age groups, proximal carious lesions were less common in the diabetics than in the controls. No notable difference was found between the mean number of erupted teeth in the diabetics and that of the controls, except among the 12- to 14-year-old children. In that age group the diabetics had, on the average, 6.0 erupted premolars compared with 7.3 in the controls and 2.7 erupted permanent second molars compared with 3.5 in the controls. The results indicate that the dietary restriction observed by the diabetics had a favorable effect in promoting a lower caries frequency on all groups of teeth and on most tooth surfaces.

A pilot study of the relationship between caries experience and surface enamel fluoride in man

Fourteen hundred and forty-seven 12–16-yr-old subjects in selected fluoridated and non-fluoridated areas were assessed for caries experience (DMFS index) and enamel fluoride (biopsy technique). Fluoride was measured as log e mass F corrected to a standardized depth. A square root transformation of decayed, missing and filled surfaces (DMFS) was carried out in order to achieve homogeneity of variance for this variable across all levels of fluoride. A simple, linear relationship was found between log e mass F and √(DMFS). Taking age into account, the Pearsonian correlation was R = 0.40, corresponding to 16 per cent of the variance explained. Within communities the fluoride-caries relationship was consistent with the overall model but could not be demonstrated as securely because of the smaller sample sizes and the limited range of fluoride values at this level of disaggregation.

Chemical protection against postirradiation dental caries

Experience with dental caries in twenty-four patients receiving irradiation for malignant lesions of the head and neck demonstrates the critical importance of cooperation by the patient, a program of strict oral hygiene, and daily self-treatment with 0.4 per cent stannous fluoride gel. The ravaging form of dental caries associated with the postirradiation period can be essentially eliminated in cooperating patients. In nine patients who were uncooperative, fifty-seven crowns were amputated and an additional seventy-five carious surfaces were found 3.75 years after irradiation. In six patients who cooperated and used the gel on a daily basis, no crowns were amputated and only one carious area was found over the same time period.

Effect of fluoride on gingivitis and dental caries in a preventive program based on plaque control

The purpose of the investigation was to estimate the relative effect of fluoride on caries in a preventive program based on meticulous plaque control. The material consisted of 82 children; 41 in the test and 41 in the control group. At the start of the study the children were 13-14 years of age. In August 1973 an examination was performed to obtain baseline data for the trial. Prophylactic treatment was given to the children once every second week. A total of 18 treatments were given during a 10-month period. In the control group an abrasive paste was used containing 5% sodium monofluorophosphate (Jodka Fluor Polerpasta). In the test group an abrasive paste was used which was identical with the control paste except that it did not contain any fluoride components. Twelve months after the baseline examination the test and control groups were reexamined. The trial demonstrated that, in children, fortnightly professional cleaning of the teeth combined with meticulous toothbrushing instructions result in (1) a high standard of oral hygiene and (2) only very few new carious surfaces. Though the control group children received fortnightly topical application of F- during the prophylactic sessions and used a fluoridated dentifrice, there was no significant difference between the two groups regarding number of new carious tooth surfaces per child per year.

ECSI-a new index for evaluating caries progression.

abstract ECSI (Extrapolated Carious Surface Increment Index) is a caries progression index which takes into account the enlargement of existing lesions as well as the initiation of new ones. It differs in principle from previously described progression indices in that it is de‐fined as an interval scale which allows expression of the increment as a single figure. It is also unique in that it relates fillings and extractions to their preceding caries state. Detailed analysis of data from caries clinical trials shows that different populations which are apparently similar as judged on the basis of conventional DMF indices can in fact be shown to be grossly different as a result of different denial treatment patterns. Furthermore, the fundamental assumption of the DMFS index that an extracted tooth is equivalent to four or five‐carious surfaces is demonstrably false; the true figure obtained from the data studied is nearer 2.25. These shortcomings have been corrected in the ECSI logic.

ECSI ‐ A new index for evaluating caries progression

abstract ECSI (Extrapolated Carious Surface Increment Index) is a caries progression index which takes into account the enlargement of existing lesions as well as the initiation of new ones. It differs in principle from previously described progression indices in that it is de‐fined as an interval scale which allows expression of the increment as a single figure. It is also unique in that it relates fillings and extractions to their preceding caries state. Detailed analysis of data from caries clinical trials shows that different populations which are apparently similar as judged on the basis of conventional DMF indices can in fact be shown to be grossly different as a result of different denial treatment patterns. Furthermore, the fundamental assumption of the DMFS index that an extracted tooth is equivalent to four or five‐carious surfaces is demonstrably false; the true figure obtained from the data studied is nearer 2.25. These shortcomings have been corrected in the ECSI logic.

The caries preventing effect of mouthrinsing with 0.025% sodium fluoride solution in Swedish children

abstractWeekly mouthrinses with 0.2% NaF solution have long been carried out with schoolchildren in Växjö, where the water fluoride (F) content is less than 0.2 parts/106. A weaker NaF solution has been tested over a 2‐year period in a double‐blind experiment. A group of 135 children aged 12‐13 years used a 0.025% NaF solution as a weekly mouth‐rinse, while a control group of an equal number of children in the same age group continued weekly rinses with 0.2% NaF solution. Clinical and radiographic caries registration was carried out at the start of the experiment, after 1 year and after 2 years. The loss of participants totalled only 17 children during the 2 years. The results showed fewer new carious surfaces in the groups treated with the weaker solution. The total number of clinically recorded new carious surfaces did not differ statistically between the groups, and the fraction of smooth surface caries showed a significant difference at the 5 % level only in the groups of girls. Radiographically recorded carious proximal surfaces on premolars and molars showed the same trend with fewer new carious surfaces in the groups treated with the weaker solution. The retention of F from mouthrinsing with the weaker solution by children 4 and 6 years of age averaged 0.23 and 0.15 mg, respectively, from 7 ml of solution. In addition to the principal interest inherent in the finding that a weaker NaF solution may have a greater caries preventive effect than a more concentrated solution, the result is of practical significance particularly for F applications for preschool children with their incomplete control of swallowing reflexes and for local treatment in areas with optimal or supraoptimal F content in the drinking water.

The effect of a preventive programme on dental plaque, gingivitis and caries in schoolchildren. Results after one and two years

Abstract The effect on plaque, gingivitis and dental caries of regularly repeated professional mechanical tooth cleaning combined with topical application of monofluoro‐phosphate was tested in a group of 192 schoolchildren, 7–14 years of age, during a 2‐year trial. They were divided into test and control groups.A baseline examination revealed that the test and control groups had a very similar oral hygiene status, degree of gingival inflammation and caries experience. Once every second week during the 2‐year period the children of the test groups were given professional oral prophylaxis including careful tooth cleaning and topical application of 5 % sodium mono‐fluorophosphate. Once every month, the children of the control groups brushed their teeth at school, under supervision, using a 0.2 % sodium fluoride solution.The results after 1 and 2 years of experiment indicate that the test group children had low Plaque Index scores (∼ 0.3), only negligible signs of gingivitis (∼ 0.25) and very low caries increment (0.1 new carious surface per year). The control group children had higher Plaque Index scores (∼ 1.0), showed signs of gingivitis (∼ 0.75), and developed on an average 3.1 new carious surfaces per year.It is suggested that the efficacy of public health programmes, based on professional tooth cleaning and topical fluoride administration, should be tested in larger groups of children and adults.

The Oral and Physical Health of Students Entering Dental School

An evaluation of the oral and physical health of 146 students entering dental school was made. The study revealed 5.77 carious surfaces and 19.86 restored surfaces per student. An average of 9.22 teeth had been restored and 332 teeth were missing in the group of students. Total dental needs (carious and defective restored surfaces) averaged 8.3 per student. The students’ medical histories revealed that the highest number of diseases that the students were experiencing involved the respiratory system, with those of the cardiovascular system next in number. An extreme need for preventive dentistry is indicated.

Bone Loss and Caries in Rats Infected with Human Streptococci

Gnotobiotic rats infected orally with various human cariogenic Streptococcus mutans strains or a Streptococcus salivarius strain exhibited greater alveolar loss of bone than control rats. The same strains also showed considerable differences in their cariogenic activity. There was a positive correlation between the extent of bone loss and carious surfaces.

Long-term study of effect of supervised toothbrushing with a sodium fluoride dentifrice.

The prolonged prophylactic effect of three years’ daily supervised toothbrushing with a 0.22% sodium fluoride effect dentifrice was studied in 113 schoolchildren. During the trial the number of new carious surfaces in the test group (57 children) was smaller than in the control group (56 children); the difference was 20% in the first year, 34% in the second, and 48% in the third. The numerical reduction found was largest for the proximal lesions. During the first two years after the end of the trial the test group showed a 13% reduction of caries. This was due mainly to a difference in caries increment on buccal surfaces. This means that no persistent prophylactic effect of great practical value could be demonstrated.

Evaluation of examiner variability and the use of radiographs in determining the efficacy of community fluoridation

DMF tooth and surface data of 11- and 12-year-old children living in a fluoridated and a low fluoride community have been obtained by two examiners, working independently. One examiner (A) used only visual findings and the other examiner (B) used visual and visual-plus-radiographic findings in making an evaluation of fluoridation. A slight but consistent difference in the level of caries-detection was demonstrated in the visual findings of the two examiners; examiner A tended to record more carious surfaces than examiner B. Very similar percentage differences were shown, however, in the caries prevalence of the children in the two communities by each examiner's sets of data. Approximately 25 per cent more carious teeth and one-third more carious surfaces were diagnosed in each community when examiner B's radiographic findings were added to his clinical findings, but the addition of radiographic findings did not appreciably alter the relative difference in caries prevalence in the two communities based on his visual findings alone. The dental benefits of community fluoridation are apparent in this report. An average of the results obtained by the two examiners showed that children in the fluoridated community had 40 per cent fewer DMF teeth and 50 per cent fewer DMF surfaces than their counterparts in the low fluoride community. According to examiner A's visual findings, 18 per cent of the 12-year-olds in Fargo had zero DMF surfaces, whereas only 1 per cent of children that age in Moorhead were free of carious surfaces. The protective effect of fluoride was found to be strikingly more apparent on approximal surfaces than on occlusal or buccal-lingual surfaces.

An experimentally supported “law of tooth decay” and its application

The “law of tooth decay” is formulated to state as follows: The change in caries experience is proportional to the products of the numbers of healthy and carious surfaces and varies inversely as the square root of the function of time (1 + t). In symbols: dy dt = λ √ (1 + t) (n − y)y The general solution of the above differential equation is: y = n exp 2λn √ (1 + t) k + exp 2λn √ (1 + t) where k = (n − y 0) exp 2λn √ (1 + t 0) y 0 The above two equations may be used to approximate future caries experience and instantaneous caries rate of change. Experimental data (fifty-seven children observed over 3 years at 6-month intervals) supported the “constant” postulation about λ and the use of (1 + t) − 1 2 . The experimental results suggest that λ = 0.0024. The time required for specified amount of decay was tabulated for selected values of n, y, α, and θ. These tables may be used by clinicians as a gauge for clinical actions in treating patients. The apparent difference in concavity of caries curves may be explained by the difference in total number of available surfaces open to the risk of decay. It was further suggested that the healthy surfaces be included as a factor in studies concerning caries rates.

Caries increments, tooth discoloration, and state of oral hygiene in children given single annual applications of acid phosphate-fluoride and stannous fluoride

One hundred and ninety-five children who received topical applications of an acidic fluoride and phosphate solution once a year for 2 years had approximately 50 per cent fewer carious surfaces than 197 children who served as a control group at the end of 2 years. Development of carious surfaces was less in children with good oral hygiene than in those with poor oral hygiene, and the caries reducing effect of topical fluoride was greater in the former group. Two hundred and eleven children treated with stannous fluoride had the same caries surface increment as the control group at the end of 1 year. Identifiable enamel staining developed in 60 per cent of the children treated with stannous fluoride.

A study of acidulated fluoride solutions—III: The cariostatic effect of repeated topical sodium fluoride applications with and without phosphate: A pilot study

In 77 children, one side of the dentition was given four topical applications with a neutral 2% sodium ftuoride solution, and the other half, four applications of this solution in 0·15 M of orthophosphoric acid. Less than half as many new carious surfaces were noted on the side treated with the phosphate fluoride solution.

A study of acidulated fluoride solutions—II: The caries inhibiting effect of single annual topical applications of an acidic fluoride and phosphate solution. A two year experience

One hundred and fifteen children who received single topical applications of an acidic fluoride and phosphate solution once a year for two years had approximately 70 per cent fewer carious surfaces than the 113 children who served as controls at the end of both first and second year.

The Influence of War and Postwar Conditions on the Teeth of Norwegian School Children. IV. Caries in Specific Surfaces of the Permanent Teeth

The Influence of War and Postwar Conditions on the Teeth of Norwegian School Children. IV. Caries in Specific Surfaces of the Permanent Teeth