A. Thylstrup

Dental Plaque and Caries on Occlusal Surfaces of First Permanent Molars in Relation to Stage of Eruption

The occlusal surfaces of partly and fully erupted first right permanent molars were examined with respect to the occurrence and distribution of plaque and dental caries in a group of 57 six- to eight-year-old children. The children were classified into four groups ranging from one tooth partially erupted to full occlusion. Occlusal plaque was recorded at two levels of examination: (1) visible plaque and (2) detailed mapping by means of a plaque detector system. Dental caries was recorded after professional cleaning. The recording of plaque was repeated after 48 hr without oral hygiene. The findings showed a significant reduction in the easily detectable plaque in fully erupted teeth, compared with the three groups representing partly erupted teeth. The detailed mapping of plaque showed a clear pattern of preferential locations related to the macromorphology of the occlusal surfaces, and revealed reduction in the frequency of thick plaque accumulation in the fully erupted teeth. The proportion of active lesions was reduced in fully erupted teeth, and arrested lesions were mainly observed in the same group. This indicated that erupting teeth are more likely to develop dental caries, due to favorable conditions for plaque accumulation. Functional usage of teeth in addition to improved access for toothbrushing promoted arrestment of lesions initiated during eruption.

Results after 3 years of non-operative occlusal caries treatment of erupting permanent first molars.

The aim of the study was to describe the 3-yr results of a treatment program designed to control occlusal caries on the basis of intensive patient education and professional toothcleaning. The sample consisted of 56 children 6-8 yr old with their permanent right first molars in different stages of eruption. The results were compared with record data from 58 children of the same age who had received a traditional caries treatment program including fissure sealing (control group). After 1 yr a significant reduction of occlusal surfaces with visible plaque was noted in the study group as well as an increased proportion of arrested lesions. These results were maintained after 2 and 3 yr. Ten (9%) teeth were sealed and one filled during the study period. Examination of record data in the control group over a 3-yr period revealed that 76 (65%) first molars were sealed and 7 (6%) were filled. During the first year 1/3 of the children in the study group needed 5-6 recall visits, whereas in the following period all children were only seen 1-4 times. In contrast, 50% of the children in the control group needed 5-6 recalls in the 3rd yr. Our data indicate that professional care for erupting teeth on an individual basis has a long-term effect on occlusal surfaces as well. The alternative technique required less clinical time than the traditional application of sealants.

Radiographic Diagnosis and Clinical Tissue Changes in Relation to Treatment of Approximal Carious Lesions

Of 158 carious lesions to be treated with restorations, 66% were found to be without macroscopical cavitation. Observed clinical tissue changes were poorly correlated to accepted standardized radiogra

Restorative treatment pattern and longevity of amalgam restorations in Denmark

A survey has been made of the reasons for placement and replacement of 6052 amalgam restorations in Denmark. In patients more than 16 years of age 48% of all restorations were made because of primary caries, and 52% were replacements of failed restorations. In primary teeth 64% and in permanent teeth of children 83% of the restorations were made because of primary caries. The reasons for replacement of restorations were dependent on dentition, age of the patient, and type of restoration. Secondary caries was the most frequent reason for replacement of failed restorations in permanent teeth, comprising a third of all replacements. Marginal discrepancies and bulk fracture of fillings were the other two major reasons. In primary teeth fracture and loss of fillings were the two major reasons for replacement of amalgam restorations, whereas secondary caries caused less than a quarter of all restorations to be replaced. The age of the restorations replaced ranged from 0 to 38 years, and half of the restorations replaced in permanent teeth of adults were less than 7 years old. A shorter longevity of failed restorations was noted in primary teeth and permanent teeth of children.

Whole Saliva Fluoride after Toothbrushing with NaF and MFP Dentifrices with Different F Concentrations

The present study was designed to assess the effect of F compound and F concentration in dentifrices on fluoride in whole saliva after ordinary toothbrushing. The dentifrices tested had the same basic

A 3-year clinical and SEM study of surface changes of carious enamel lesions after inactivation

The surface features of incipient carious lesions around bonded orthodontic brackets were assessed during a 3-year period after appliance removal. At standardized intervals color slides and silicone impressions for replication were made of two maxillary incisors on each of six adolescent patients. The labial surfaces of the teeth had demineralized white areas around the bonded brackets. The color slides were projected and studied in a darkroom. The positive surface replicas were studied by scanning electron microscopy (SEM). At the time of debonding, large accumulations of dental plaque were observed in those areas with white, demineralized surfaces. During the posttreatment or experimental period, there was a reduction in the amount of plaque. The appearance of the lesions changed from chalky-white at time of debonding to a more diffuse opacity, particularly in the peripheral parts. Under SEM the surfaces of the lesions were less irregular 3 years after debonding. At higher magnification the labial surfaces showed signs of wear. The present study confirms that removal of cariogenic challenge results in arrest of further demineralization. The gradual regression of the lesion at the clinical level is believed to be primarily a result of surface abrasion.

Radiographic and Observed Tissue Changes in Approximal Carious Lesions at the Time of Operative Treatment

Clinical tissue changes in 1,080 approximal carious lesions at the time of operative treatment were recorded by 263 Danish dentists. The findings were related to type of tooth, age of the patient, and

Clinical and histological features observed during arrestment of active enamel carious lesions in vivo.

The aim of the present study was to examine clinical and histological events taking place in vivo during the initial period of arrestment of active enamel carious le sions. For this purpose we developed lesions in vivo during a period of 4 weeks. To ensure plaque accumulation, orthodontic bands with a standardized buccal space were placed on 4 premolars in each of 4 patients undergoing orthodontic treatment. After 4 weeks with local cariogenic challenge, all teeth were debanded and one tooth in each patient extracted as control. All teeth had ‘white spot lesions’ corresponding to the plaque retention area. No professional tooth cleaning was performed. The remaining teeth were extracted 1 2, or 3 weeks after debanding. No fluoride was added during the entire test period and the patients were told to maintain usual oral hygiene. A gradual regression of the lesions in terms of reduction in lesion area and degree of opacity was noted during the following 3 weeks. The polarized light examinations disclosed a prompt reaction to the removal of the bands as no further lesion progress was noted. In addition we observed a decrease in tissue porosity especially in the deepest parts of the lesions while the outer surface appeared more porous than in the base-line lesions.

A Scanning Electron Microscopic Study of Progressive Stages of Enamel Caries in vivo

The present study was carried out to describe surface changes in the scanning electron microscope as related to different periods of carious dissolution in vivo. To ensure accumulation of microbial plaque, orthodontic bands with a standardized buccal space were placed for periods of 1, 2, 3 and 4 weeks on permanent premolars prior to extraction. Examinations in polarized light disclosed a gradual development of a subsurface lesion over time. In the SEM direct dissolution of the surface itself was a prominent feature at all stages of lesion development causing a universal enlargement of intercrystalline spaces. Results indicate that enlarged intercrystalline pathways provide the most important routes for the transport of minerals out of the enamel. The relative protection offered to the outermost crystals at any stage of lesion formation may be an indication of inhibitors acting at the plaque/enamel interface and/or calcium and phosphate present in the plaque.

Enamel Changes and Dental Caries in 7-Year-Old Children Given Fluoride Tablets from Shortly after Birth

In 1969, a caries preventive program was initiated in a part of Denmark where parents of infants were offered prescriptions for fluoride tablets for daily use. When requested new prescriptions were su