Biomedical subjects

S Twetman

Publications and source records attributed to S Twetman.

At least 19 recordsLinked to original sources

PubMed2000

Decreasing prevalence of salivary lactobacilli in Swedish schoolchildren 1987-1998.

The prevalence and number of salivary lactobacilli was determined in all schoolchildren starting the 7th grade (12-13 yr; n = 1,578) in comprehensive school located in Kumla, Sweden between 1987 and 1998. Whole saliva samples were collected and transferred to dip-slides (Dentocult-LB) and incubated in room temperature for 7 d. Caries data were collected from the dental records and from bitewing radiographs. Both the number of lactobacilli and the prevalence of manifest caries and restorations exhibited a decreasing tendency and were significantly lower in 1998 than in 1987. The mean caries prevalence (DFS) declined from 5.2 to 1.8. In 1987, 45% of the children harboured high or very high lactobacilli counts ( > or =10(5) CFU/ml) in their saliva compared to approximately 10-15% at the later examinations. The proportion of children with no detectable counts varied between 4-29% during the study period, while children with low counts (10(3)-10(4) CFU/ml saliva) constituted a clear majority at the recent samplings. With such low levels in the population, the use of lactobacilli counts as a didactic tool in dietary counselling must be called into question.

Adolescent↗

PubMed2000

Infant oral health.

According to the United Nations' Convention on "The Rights of the Child," articles 2 and 24, all children should have the same rights and have right to health and medical service. Early childhood caries is a lifestyle disease with biologic, behavioral, and social determinants. An early screening of all children at around 1 year of age is an excellent opportunity for early detection of risk factors and risk indicators that may increase the possibilities for its prevention. The caries risk evaluation should form the base for appropriate recommendations of preventive measures. The preventive care must be coordinated with an eventual operative care and should be based on education of prospective and new parents as well as professional and home-based measures. The various interventions must be developed further and evaluated in prospective studies in terms of effectiveness and efficiency for this specific age group. This is an urgent task for dental professionals and all societies with the ambition of providing good dental care for all young children.

Child↗

PubMed1999

Salivary mutans streptococci and lactobacilli in 9- and 13-year-old Italian schoolchildren and the relation to oral health.

The prevalence and levels of mutans streptococci (MS) and lactobacilli (LB) in saliva and its possible correlation with dental caries and periodontal conditions was investigated in 473 Italian schoolchildren, 9 and 13 years of age. A clinical examination and sampling of stimulated whole saliva was carried out in the school and oral health was assessed as DMFT and CPITN using the WHO criteria. The saliva samples were frozen in liquid nitrogen and after thawing, cultivated on selective media. To test the influence of cryopreservation, fresh samples from 20 subjects were cultivated. Thirty-five percent of the children were caries-free with a mean DMFT of 1.9 at the age of 13. The majority exhibited healthy periodontal conditions. Salivary MS and LB were identified in 52% and 21% of the children, respectively. The prevalence of MS was higher among the 13-year-olds than the 9-year-olds while no such difference was found regarding LB. There was a statistically positive relationship (P < 0.01) between the levels of MS and LB and both were significantly correlated to caries (P < 0.01). The correlation coefficient of microbial recovery between frozen and unfrozen samples was 0.99. In conclusion, the data provided cross-sectional information of a clear positive relationship between selected micro-organisms in saliva and caries in 9- and 13-year-old children in spite of a relatively low prevalence of the disease. The findings are discussed in a risk selection perspective.

Adolescent↗

PubMed1999

Pre- and post-treatment levels of salivary mutans streptococci and lactobacilli in pre-school children.

OBJECTIVES: To examine the effect of operative and restorative treatment of dental caries on the levels of caries associated microorganisms in saliva and to relate alterations to the type and extent of treatment. DESIGN: Longitudinal. SETTING: Paediatric Dentistry Department at a central hospital in Sweden. SUBJECTS AND METHODS: One hundred and eight pre-school children with severe dental caries scheduled for treatment under general anaesthesia. Chair-side tests were used to estimate the levels of salivary mutans streptococci, lactobacilli and buffer capacity before the surgery and at recall appointments 1 and 6 months after treatment. Caries were assessed according to WHO guidelines and the number of extracted teeth and filled surfaces during surgery were recorded. RESULTS: The results demonstrate that the post-treatment levels of mutans streptococci and lactobacilli were significantly reduced (P < 0.001) compared to pretreatment levels. Lactobacilli levels were more dramatically reduced than mutans streptococci. The reduction of mutans streptococci was positively correlated to the number of extracted teeth (P < 0.01), but not to the number of restored or ground surfaces. Lactobacilli reduction was not significantly related to the type of treatment. CONCLUSION: The findings suggest that extensive operative and restorative dental care effectively reduces the levels of caries associated with microorganisms during a period of at least 6 months.

Anesthesia, Dental↗

PubMed1999

Fluoride concentration in whole saliva and separate gland secretions after topical treatment with three different fluoride varnishes.

Fluoride concentration in whole saliva and in separate gland secretions was determined after a single application of each of 3 different fluoride varnishes with contrasting levels of fluoride in a randomized crossover design. The study group comprised 8 healthy schoolchildren aged 10-12 years treated with A: Bifluorid 12 (6% F); B: Duraphat (2.26% F); and C: Fluor Protector (0.1% F). Unstimulated and stimulated whole saliva, as well as stimulated parotid and submandibular-sublingual saliva, were collected at baseline and 1, 6, 12, and 24h after the varnish treatments. The fluoride concentrations were determined with an ion-selective electrode. Time- and dose-dependent concentration curves were obtained in all the collected secretions, A > B > C. In whole saliva, the fluoride levels were significantly elevated (P<0.01) 1 h after the A and B varnish applications compared with baseline, while the increase was insignificant for varnish C. Similar patterns were unveiled in the parotid and submandibular-sublingual secretions, although the increase in fluoride concentration was modest. The elevated levels did not exceed 6 h for any of the varnish tested. The results of this study suggest a correlation between the concentration of fluoride of the varnish and fluoride levels obtained in saliva after application.

Calcium Fluoride↗

PubMed1999

Interdental caries incidence and progression in relation to mutans streptococci suppression after chlorhexidine-thymol varnish treatments in schoolchildren.

The aim of this study was to evaluate interdental caries incidence and progression in relation to the effect of antibacterial varnish treatments in schoolchildren anticipated at caries risk. After a screening procedure, 110 healthy children (8-10 years) with moderate and high counts of salivary mutans streptococci (MS) were invited to join a 2-year longitudinal study. At baseline, MS were enumerated at all mesial interdental sites of the first permanent molars with a chair-side technique. The children were then treated 3 times within 2 weeks by interdental spot applications with a 1% chlorhexidine/thymol-containing varnish (Cervitec). Follow-up samples of saliva and plaque were collected 1, 3, 6, and 12 months after onset of treat. Caries prevalence, incidence and progression of the selected approximal surfaces were scored from bitewing radiographs exposed at baseline and after 2 years. Sixty-three children of the same age formed a non-varnish-treated reference group. Reduction of caries incidence and progression was dearly dependent on the outcome of the antibacterial treatment. A significantly (P< 0.01) higher progression score was found among children who exhibited a less marked suppression of interdental MS levels compared with those with high suppression and the children of the reference group. The results suggest that a suppression of MS in interdental plaque may be an important event to prevent and arrest approximal caries development in schoolchildren at risk. Monitoring the effect of antibacterial agents in a site-specific way could therefore be advocated.

Analysis of Variance↗

PubMed1999

Effect of an antibacterial dental varnish on the levels of prostanoids, leukotriene B4, and interleukin-1 beta in gingival crevicular fluid.

The aim of this study was to investigate the effects of a chlorhexidine/thymol-containing dental varnish on the levels of prostaglandin E2 (PGE2), prostaglandin I2 (PGI2), leukotriene B4 (LTB4), and interleukin-1 beta (IL-1 beta) in gingival crevicular fluid (GCF). The material consisted of 15 adolescents undergoing treatment with fixed orthodontic appliances. Four buccal sites adjacent to bands or brackets and exhibiting a mild chronic gingival inflammation were selected in the upper quadrants of each patient. According to a split-mouth technique, the first and second quadrants were randomly treated with either a varnish (Cervitec) containing 1% chlorhexidine diacetate and thymol (CHX/thymol) or a placebo varnish without active ingredients. The varnishes were applied immediately after the baseline registration, and follow-up examinations were carried out after 3, 8, and 30 days. GCF was sampled with the aid of a paper strip and the volume was determined using a Periotron 8000. The concentrations of PGE2, PGI2, LTB4, and IL-1 beta in GCF were assessed using radioimmunoassay and ELISA techniques. The results unveiled statistically significant reductions of PGE2, PGI2, and LTB4 levels in GCF following the active varnish treatment when compared to baseline values. A slight drop in IL-1 beta levels was registered after both active and placebo varnish applications, but the differences were not significant. The results suggest that treatment with an antibacterial varnish decreases the levels of inflammatory mediators PGE2, PGI2, and LTB4 in gingival crevicular fluid and further support the concept that topical application of a CHX/thymol-containing varnish is beneficial in patients with chronic gingival inflammation.

Adolescent↗

PubMed1999

Mutans streptococci suppression by chlorhexidine gel in toddlers.

PURPOSE: The effect of daily toothbrushing with a chlorhexidine gel on the levels of oral mutants streptococci was evaluated in a group of 37 healthy 1 1/2-year-old children. MATERIALS AND METHODS: The microbial samplings were performed with a modified Strip mutans chair-side technique: a sterile cotton pellet on a wooden pin was rolled along the surfaces of the upper primary incisors and then rolled again on a specially prepared plastic strip. The strips were thereafter incubated and cultivated in a selective media. After baseline registrations, the parents were instructed and trained to brush the teeth of their children with a 1% chlorhexidine gel (Corsodyl), twice daily during 14-days. Follow-up samplings were obtained 1 and 3 months after termination of gel treatment. RESULTS: The results revealed a statistically significant (P < 0.01) reduction of mutans streptococci colonization after 1 month compared with baseline. After 3 months, a certain reduction was still evident although not statistically significant from baseline.

Analysis of Variance↗

PubMed1998

Effect of a chlorhexidine/thymol-containing varnish on prostaglandin E2 levels in gingival crevicular fluid.

The aim was to study the effect of a chlorhexidine/thymol-containing varnish (Cervitec) on the levels of prostaglandin E2 (PGE2) in gingival crevicular fluid (GCF). The material consisted of 25 adolescents and young adults with fixed orthodontic appliances exhibiting gingival inflammation. Four buccal sites, adjacent to bands and brackets, were selected on each patient and randomly treated with either a varnish containing chlorhexidine diacetate (1% w/w) and thymol (1% w/w) or a placebo varnish without active ingredients. After baseline registration, the varnishes were applied twice within 3 d. Follow-up examinations were performed after 3, 8 and 30 d. The gingival inflammation was assessed by bleeding on probing, volume of GCF with a Periotron 8000 and PGE2 level in GCF by using a radioimmuno assay. Compared with baseline, a statistically significant reduction in the volume of GCF was recorded at the chlorhexidine/thymol treated sites in contrast to the placebo. The mean PGE2 levels were significantly reduced after the test varnish treatment compared with baseline and differed significantly from placebo after 8 d. The findings suggest that treatments with the antibacterial varnish result in reduced gingival inflammation and may thus be beneficial for patients with fixed orthodontic appliances.

Adolescent↗

PubMed1998

Effect of semi-annual applications of a chlorhexidine/fluoride varnish mixture on approximal caries incidence in schoolchildren. A three-year radiographic study.

Development and progression of approximal caries is still difficult to prevent and control even in societies with declining caries prevalence. In this study, a test group of 115 12-yr old children were treated semi-annually with a mixture (1:1) of a varnish containing 0.1% F (Fluor Protector) and 1.0% chlorhexidine (Cervitec). A reference group of 104 children received fluoride varnish treatment (Fluor Protector) semi-annually. Approximal caries was recorded from bitewing radiographs at baseline and after 3 yr. At baseline, total decayed and filled surfaces (DFS) including enamel caries were 1.79+/-2.36 in the reference group and 2.0+/-2.77 in the test group. After 3 yr, the mean approximal caries incidence including enamel caries was 3.01+/-3.74 and 3.78+/-4.32, respectively. The differences at baseline as well as after 3 yr were not statistically significant. The results showed that both groups had a comparatively low incidence of approximal caries during the experimental period, and suggest that a mixture of fluoride and antibacterial varnish had no additional preventive effect on approximal caries incidence compared with fluoride varnish treatments alone.

Anti-Infective Agents, Local↗

PubMed1998

The efficiency of semiannual silane fluoride varnish applications: a two-year clinical study in preschool children.

OBJECTIVE: The aim of this two-year community demonstration trial was to study the caries inhibitory effects of semiannual applications of a fluoride varnish in preschool children. METHODS: Twenty-four public dental health clinics in the county of Halland, Sweden, with 5,137 preschool children, 4 and 5 years of age, were matched and equally allocated to a fluoride varnish group (n = 2,535) and a reference group (n = 2,602). The children in the fluoride varnish group were treated every six months with topical applications of a silane fluoride varnish, Fluor Protector (0.1% F), while no fluoride varnish was used in the reference group. Both groups received a basic preventive program at annual checkups consisting of dietary counseling and instructions to parents to brush their children's teeth at least once daily with fluoridated dentifrice. Caries data were collected by clinical examinations at baseline and after one and two years. RESULTS: Caries prevalence at baseline did not differ significantly between the groups. After two years, the mean caries incidence was low and no statistical difference was found in the total number of carious and filled surfaces (dfs) between the two groups. However, the incidence of approximal lesions (dfsa) was significantly lower (P < .05) in the fluoride varnish group than the reference group. Children in the fluoride varnish group with dfs scores of 1-4 and > or = 5 at the start of the study exhibited a statistically significant (P < .05) reduction in approximal caries incidence of 19 percent and 25 percent, respectively, when compared with the reference group. CONCLUSION: Preschool children 4 and 5 years of age with clinical caries who receive semiannual applications of a silane fluoride varnish containing 0.1 percent F experience a reduced incidence of approximal caries over two years.

Cariostatic Agents↗

PubMed1998

Comparison of the efficacy of three different chlorhexidine preparations in decreasing the levels of mutans streptococci in saliva and interdental plaque.

The aim of the present study was to evaluate and compare the effects of three different chlorhexidine (CHX)-containing preparations on mutans streptococci (MS) levels in interdental plaque and whole saliva. Ninety-three healthy school-children (8-10 years old) with high scores of salivary MS were selected by a screening procedure and randomised into three equally sized groups. MS were enumerated at all mesial interdental sites of the first permanent molars with aid of a modified chairside technique. The patients were then treated three times within 2 weeks with either a 1% CHX/thymol-containing varnish (group A) or a 1% CHX gel (group B), or they were subjected to daily supervised toothbrushing with a 0.4% CHX dentifrice for 1 month (group C). Follow-up samples of saliva and plaque from the interdental sites were collected 1 and 3 months after termination of treatment. A statistically significant reduction of MS levels in saliva and interdental plaque was found in all groups after 1 month. The CHX-containing dentifrice (group C) was the most effective method in reducing MS levels in saliva, and a significantly stronger (p < 0.05) suppression was found after 1 and 3 months when compared with the gel and the varnish forms. The gel (group B) tended to be slightly more effective than the varnish (group A). In the interdental plaque, the reduction of MS was less marked than in the saliva, and the three groups exhibited MS reductions of similar magnitude (20%) and duration, persisting up to 3 months. However, a high proportion (approximately 50%) of all interdental sites were relatively unaffected by the treatments. In conclusion, our results suggest that the interdental MS colonisation was difficult to combat, irrespective of CHX preparation and method, while the salivary levels were more easily affected. Daily tooth-brushing with a CHX-containing dentifrice was more effective in reducing MS in saliva compared with the gel or varnish applications.

Analysis of Variance↗

PubMed1998

Fluoride concentration in whole saliva and separate gland secretions in schoolchildren after intake of fluoridated milk.

Fluoride concentration in whole saliva and in separate gland secretions was studied after a 7-day fluoridated milk regimen (1mg F per day) in 12 healthy schoolchildren aged 10-13 years. A 2-week fluoride-free run-in period preceded the tests in order to establish the endogenous baseline levels. Unstimulated and stimulated whole saliva and stimulated parotid and submandibular-sublingual saliva were collected at 1, 3, 6, 12 and 24h after F-milk ingestion, and fluoride concentrations were determined with an ion-selective electrode. Typical time-dependent excretion curves were obtained in all collected secretions. The fluoride levels were significantly elevated 1 and 3h in whole saliva and up to 6h in the gland secretions after intake of fluoridated milk when compared to baseline values. When acid-stimulated, the submandibular-sublingual glands were the major contributors of fluoride in the oral cavity. In conclusion, the results of this study demonstrate that fluoride ingested with milk is excreted through the salivary glands, indicating that the bioavailability of fluoride from milk equals that of other vehicles.

Adolescent↗

PubMed1997

Effect of different chlorhexidine varnish regimens on mutans streptococci levels in interdental plaque and saliva.

The aim of the present study was to evaluate and compare the effects of an intensive and a monthly mode of antibacterial varnish application on the levels of mutans streptococci (MS) in interdental plaque and whole saliva. Eighty-eight healthy schoolchildren (11-13 years) with high scores of salivary MS were selected by a screening procedure and randomised into two groups, MS were enumerated at all mesial interdental sites of the first permanent molars with the aid of a modified chair-side technique, disclosing a total of 161 sites with moderate or high colonisation levels. The subjects were treated with a 1% chlorhexidine-thymol-containing varnish (Cervitec) either in an intensive mode (IM) with 3 applications within a 2-week period or in a monthly mode (MM) during a 3-month period. The varnish was applied with a miniball burnisher after the teeth had been cleaned interdentally with dental floss and dried with air. Follow-up samples of saliva and plaque from the interdental areas were collected after 1, 3 and 6 months. Both groups exhibited a statistically significant (p > 0.05) reduction of interdental MS after 1 month when compared with baseline. An eliminated MS growth appeared more frequently following the IM compared with the MM. After 3 months, a significant reduction compared with baseline was still found in the IM group but not in the MM group. No reduction was found in either group after 6 months. MS levels in saliva were mainly unaffected at the follow-up samplings, with the exception of a slight reduction in the IM group after 1 month. In conclusion, the results suggest that an intensive mode of chlorhexidine-thymol varnish application is more effective against interdental MS than the monthly mode of application. Bacterial growth should be monitored in a site-specific way, since interdental reductions were not adequately reflected in whole saliva samples.

Administration, Topical↗

PubMed1997

Efficacy of a chlorhexidine and a chlorhexidine-fluoride varnish mixture to decrease interdental levels of mutans streptococci.

The aim of the present study was to evaluate and compare the efficacy of a chlorhexidine/thymol-containing (CHX) and a chlorhexidine/thymol/fluoride-containing (CHX + F) varnish to decrease interdental levels of mutans streptococci (MS). Eighty-two healthy schoolchildren (11-13 years) with high scores of salivary MS were selected by a screening procedure and randomised into two groups. MS were enumerated at all mesial interdental sites of the first permanent molars with the aid of a modified chair-side technique. The interdental molar and premolar sites were treated with either a 1% CHX varnish (Cervitec) or a 1:1 mixture of the CHX varnish and a fluoride varnish containing 0.1% w/w difluorsilane (Fluor Protector; CHX + F) on two occasions within a 2-week period. The varnishes were applied with a small brush after cleaning with dental floss and drying with air. Follow-up samples from the interdental areas were collected after 1 and 3 months. Both groups exhibited a similar statistically significant (p < 0.05) reduction of interdental MS after 1 month when compared with baseline. After 3 months, a significant reduction (p < 0.05) was still found in the CHX + F varnish group but not in the CHX varnish group. In conclusion, the results suggest that the addition of fluoride to an antibacterial varnish might improve the long-term efficacy in diminishing the cariogenic microbial challenge. Thus, the mixed varnish concept should be further developed and warrants an implementation of clinical studies.

Adolescent↗

PubMed1997

Cariostatic effect of glass ionomer retained orthodontic appliances. An in vivo study.

The cariostatic effect of a fluoride releasing bonding agent was investigated and compared with a conventional composite based material in connection with bonding of orthodontic brackets in 22 homologous pairs of premolars. All subjects had malocclusions requiring orthodontic treatment with fixed appliances and extraction of at least two premolars. 6-13 weeks prior to extraction, orthodontic brackets were bonded to the labial surfaces of the extraction teeth with either a glass ionomer cement or a bis-GMA resin. Initially, the children were instructed in tooth brushing and the regular use of fluoride. After extraction, the bonded teeth were stained and evaluated in a stereo-microscope regarding the incidence and extension of initial enamel demineralisation. The zone of intact enamel adjacent to the bracket base and bonding material was measured in a stereo-microscope at four predetermined locations with the aid of an electronic ruler and scored according to four categories. The incidence of enamel demineralisation adjacent to glass ionomer bonded and composite bonded brackets was 68% and 77% respectively. In 12 pairs of premolars however, the demineralisation appeared to a lesser extent on the enamel around the brackets was generally wider when glass ionomer cement was used compared to the composite resin. These differences were statistically significant (p < 0.05) mesially and distally, but non-significant cervically and incisally. The results indicate that bonding with glass ionomer cement may have a local cariostatic effect in children requiring fixed orthodontic appliances.

Adolescent↗

PubMed1997

2-year clinical performance of a fluoride-containing fissure sealant in young schoolchildren at caries risk.

PURPOSE: To evaluate the clinical performance of Helioseal-F, a fluoride-containing fissure sealant, in school children at caries risk. MATERIALS AND METHODS: A caries risk assessment based on past caries experience, saliva microbial tests, buffer capacity and frequency of sugar intake was carried out in 204 healthy children, 6-7 years of age. Children exhibiting one or more risk factors were considered at caries risk (n = 121) and their permanent molars were sealed with a fluoride-containing fissure sealant, thus forming a fissure sealant group (FSG). The remaining 83 children with low caries risk received no fissure sealants and constituted a reference group (RG). Both groups were followed for 2 years. From 15 children of both groups, unstimulated whole saliva was collected 1 month after sealant placement in order to determine fluoride levels. In another 20 children, a split-mouth study design was utilized to compare the colonization of mutans streptococci adjacent to and on F-containing sealants and conventional controls. The sealants were placed by dental hygienists according to the manufacturers' instructions. RESULTS: A total of 431 fissure sealants were placed at baseline. Complete retention was found in 76.6% during the study period while 22.0% were partially lost. Six sealants (1.4%) were completely lost. The enamel caries incidence was 45% lower (P < 0.05) in the permanent molars of the caries risk FSG compared with the low risk RG. There was no significant increase in saliva fluoride concentration following placement of the sealants and the proportion of mutans streptococci in relation to total viable counts was unaffected by type of material. The levels of salivary mutans streptococci were mainly unchanged in both groups during the study period, while the levels of salivary lactobacilli decreased in the FSG.

Analysis of Variance↗

PubMed1996

Saliva composition in children and young adults with Papillon-Lefèvre syndrome.

The aim of the present study was to evaluate the salivary secretion rate and composition in a group of 16 children and young adults (6-27 years) with Papillon-Lefèvre Syndrome (PLS), and to compare the findings with a group (n = 16) of healthy controls. Unstimulated and stimulated whole saliva was collected at least 2 h after meals and the secretion rate determined. The stimulated saliva was assessed for buffer capacity, total protein, peroxidase and hexosamine, while the unstimulated samples were evaluated for total protein, lysozyme, thiocyanate, lactoferrin and salivary IgA. Both the unstimulated (p < 0.01) and stimulated (p < 0.05) saliva secretion rates were significantly lower among the PLS patients compared with the controls. Furthermore salivary buffer capacity was significantly (p < 0.01) lower in the PLS patients. The total protein content in saliva was comparatively high in the study group, while the concentrations of immunoglobulins and non-immunoglobulins were within normal ranges. When calculating the output of the assessed antimicrobial factors, the mean peroxidase level in stimulated whole saliva was found to be significantly (p < 0.01) lower in the PLS patients than in the healthy controls. In conclusion, the present study indicates an impaired water secretion and a somewhat altered saliva gland function in children and young adults with PLS.

Adolescent↗