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Biomedical subjects

L Matsson

Publications and source records attributed to L Matsson.

68 records · Page 4Linked to original sources

Margin adaptation of dispersion and traditional amalgams with reference to plasticity: a clinical comparison.

Margin adaptation of dental amalgam restorations made from traditional vs. dispersion-type alloy was compared by clinical evaluation with the reference to plasticity of the mix at insertion. Also, variations in sealing properties were assessed for precondensed and not-precondensed amalgam mixes of both alloys. The data presented confirm the clinical superiority of amalgam made from dispersed type alloy. A higher plasticity tended to result in less margin deterioration for amalgams of the traditional type alloy. In vitro leakage with the dispersion type amalgam far exceeded that of the traditional amalgam.

Chemical Phenomena↗

Gingival inflammation in diabetic children related to degree of metabolic control.

Earlier studies indicate that diabetic children are less resistant to periodontal disease than healthy children. As the degree of metabolic control of the diabetes ranges widely in a juvenile population, the susceptibility to gingival inflammation may vary. The aim of the present study was to compare the gingival status in diabetic children, subgrouped for control of the disease, with that in non-diabetic children. All comparisons were performed under controlled plaque conditions. 43 diabetic children took part in the study. The controls consisted of age- and sex-matched healthy children. The degree of gingival inflammation and the amount of bacterial plaque were assessed in terms of the Gingival Index and the Plaque Index, respectively. The Plaque Index scores constituted the basis for all comparisons of gingival status. The metabolic control of the diabetics was assessed from the amount of glycosylated hemoglobin fraction HbA1c. For children with the highest Plaque Index scores, diabetics showed statistically significantly higher Gingival Index scores. Only minor differences were seen in the other Plaque Index classes. The diabetic children with poor metabolic control showed a clear tendency towards higher Gingival Index scores than the non-diabetics, while no such tendency was seen between the diabetics with good metabolic control and the non-diabetics.

Adolescent↗

Histologic characteristics of experimental gingivitis in the juvenile and adult beagle dog.

An earlier study (Matsson & Attström 1979) revealed an unexplained difference between juvenile and adult dogs in the propensity to develop clinical signs of gingivitis. The aims of the present investigation were to depict the structural composition of clinically normal gingiva and to analyze the histologic changes in the gingiva during plaque development in juvenile and adult dogs. Six beagle dogs were used. Two periods of discontinued oral hygiene were studied, the first at 3 and the second at 12 months of age. Biopsies were sampled on days 0, 4, 7, 14, 21 and 28 of each period. Sections from the biopsies were analyzed at two levels of magnification. Compared to adult dog gingiva, juvenile gingiva seemed to display: 1) a thicker keratinized layer of the oral epithelium, 2) a junctional epithelium that structurally resembles the oral epithelium, 3) a cuticular structure at the surface of the junctional epithelium, 4) a limited mononuclear inflammatory cell response during experimental gingivitis, and 5) a delayed establishment of an infiltrated connective tissue portion during experimental gingivitis. In addition, during experimental gingivitis, subgingival plaque formed along the tooth surfaces to a lesser extent in the juvenile stage compared to adult dogs.

Age Factors↗

Electron microscopic study of junctional and oral gingival epithelia in the juvenile and adult beagle dog.

A previous study demonstrated structural differences in the junctional epithelium between juvenile and adult dogs. In juveniles the junctional epithelium showed some resemblances to the oral gingival epithelium, and a cuticular structure at the dento-gingival junction was of particular interest. The oral gingival epithelium is considered to be less permeable than the junctional epithelium. As cytoplasmic filaments are held to be the main component in the process of keratinization, and to have a stabilizing influence on the cells and tissues, the present investigation was designed to study the relative amounts of cytoplasmic filaments in the junctional and the oral epithelia of beagle dogs during juvenile and adult stages. In addition, the ultrastructure of the dento-gingival junction was characterized. Six beagle dogs were used. The material consisted of gingival biopsies sampled when the dogs were 3 and 12 months old, respectively. On these occasions the gingiva was in excellent health. The biopsies were prepared for electron microscopic analysis and three randomly selected fields were recorded photographically from each of the following epithelial strata: basal and granular cell layers of the oral epithelium and basal and superficial cell layers of the junctional epithelium. Morphometric analysis was performed in order to estimate the density of cytoplasmic filaments of the cells in these epithelial strata. The amount of cytoplasmic filaments was considerably lower in the cells of the junctional epithelium than in those of the oral epithelium. In the oral epithelium the amount increased from basal towards superficial cells, whereas no such increase was seen in the junctional epithelium. The pattern was the same in the juvenile and the adult stage. At the dento-gingival junction all dogs had a thick, laminated layer of dental cuticle material in the juvenile stage. In the adult stage a similar structure was seen only infrequently, and it never attained the thickness observed in the juvenile stage.

Age Factors↗

Intraindividual effect of daily supervised flossing on caries in schoolchildren.

The aim was to study the effect of flossing on proximal caries in children grouped according to different combinations of dietary and oral hygiene habits. 140 12--13-year-old children flossed the right or the left lateral region of the mouth once every school-day for 2 years by pulling a waxed floss once up and down through the proximal contacts. Proximal caries was recorded on bitewing films, taken at the baseline and at the 2-year registration. Diet history was obtained four times during the period. Oral hygiene was classified according to the number of bleeding points registered with a feather-loaded probe at the final examination. Caries increments on the control side during the experimental period were calculated for groups with the same habits. A logical border with respect to the amount of new caries was then established between suitable and unsuitable dietary habits as well as between sufficient and insufficient oral hygiene. No statistically significant difference was found between the control and experimental subgroups in the different combinations of dietary and oral hygiene habits, neither with respect to the whole material nor comparable contralateral surfaces. The numerical differences were so small that the technique of flossing studied here cannot be recommended.

Child↗

Development of gingivitis in pre-school children and young adults. A comparative experimental study.

Earlier studies suggest that children and adults differ in the propensity to develop gingivitis when oral hygiene is abandoned. To confirm the existence of such a difference, a comparative study of pre-school children and young adults was made with objective registration methods. The author performed all registrations. After a period of intensive oral hygiene, all cleaning of teeth was discontinued for 21 days. The amount of bacterial plaque, the amount of gingival exudate and crevicular leukocytes and the bleeding tendency were registered on days 0, 7, 14 and 21. During the experiment the amount of bacterial plaque increased continously in both groups. The amount of gingival exudate and the tendency to gingival bleeding increased to high values in the adults, while only a small rise was seen in the children. The amount of crevicular leukocytes increased in both groups, but the increment was greater in the adults. A comparison concerning differences in gingival exudate and bleeding tendency between pre-school children and adults was undertaken for gingival units that showed a similar plaque development. Under these statistically acceptable prerequisites, it was shown that there is a real difference in the tendency to develop gingivitis between pre-school children and adults.

Adult↗

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.

Adolescent↗

Growth and development considerations in the diagnosis of gingivitis and periodontitis in children.

Increasing information emphasize the relevance of the prevention, early diagnosis and early treatment of periodontal diseases in children. In order to avoid erroneous diagnosis and unnecessary treatments, the pediatric dentist is required to differentiate between pathologic processes and normal changes that take place in the periodontum with age. The present review outlines structural and functional changes of the periodontal structures, the establishment and maturation of the oral microflora and immune defense reactions to periodontal pathogens in children and adolescents. The age-related tendency to develop gingivitis, that is evident in children and adolescents, may be related to changes in the bacterial composition of the dental plaque, the inflammatory cell response, hormonal changes, morphological differences, tooth eruption and shedding. The hormonal influence on the gingival tissues and the composition of the dental plaque are of particular relevance during puberty. Large ranges for the prevalence of attachment loss, periodontitis or destructive periodontal disease in children and adolescents have been reported. The variance in values may be related to population characteristics, method of examination or diagnostic criteria that may include measurements of attachment loss and distances from the cementoenamel junction to the alveolar bone crest, both of which may be either physiological or pathological. The pediatric dentist should be able to diagnose gingival inflammation, attachment loss or distances from the cementoenamel junction to the alveolar crest which are out of proportion to the child's age and the amount of dental plaque. These may be indicative of a high susceptibility to periodontal diseases or reflect systemic conditions that affect the periodontum.

Adolescent↗

Histologic characteristics of the gingiva associated with the primary and permanent teeth of children.

The severity of the gingival inflammatory response to dental plaque increases with age, and it has been suggested that this phenomenon may be related to histological characteristics of the gingiva. The objective of this study was to compare the histological characteristics of the gingival tissues of primary teeth with that of permanent teeth in children. Prior to extraction, children were subjected to a period of thorough oral hygiene. Histological sections prepared from gingival biopsies were examined using the light microscope. One biopsy from each of seven primary and seven permanent teeth of 14 children, whose mean ages were 11.0 +/- 0.9 and 12.9 +/- 0.9 years respectively, was obtained. All sections exhibited clear signs of inflammation. Apical migration of the junctional epithelium onto the root surface was associated only with the primary teeth. Compared with the permanent teeth, the primary teeth were associated with a thicker junctional epithelium (P < 0.05), higher numbers of leukocytes in the connective tissue adjacent to the apical end of the junctional epithelium (P < 0.05), and a higher density of collagen fibers in the suboral epithelial connective tissue (P < 0.01). No significant differences were noted in the width of the free gingiva, thickness of the oral epithelium, or its keratinized layer. In conclusion, this study indicates significant differences in the microanatomy of the gingival tissues between primary and permanent teeth in children.

Child↗