Biomedical subjects

S Twetman

Publications and source records attributed to S Twetman.

At least 55 records · Page 3Linked to original sources

PubMed1995

Effects of the antihypertensive drug captopril on human salivary secretion rate and composition.

The effects of the antihypertensive drug captopril on salivary secretion rate and composition was evaluated in 24 healthy adults (18-46 yr) according to a double-blind, cross-over design. Unstimulated and paraffin-chewing stimulated whole saliva and 3% citric acid stimulated parotid and submandibular-sublingual (SM-SL) secretion were collected at 10.30 a.m. (about 2h after intake of breakfast) on day 0 (baseline values), day 1 (experimental acute values) and day 7 (experimental chronic values) in each treatment period. In 8 of the subjects, also morning samples were collected at 7.30 a.m., with the test subjects in a fasting condition. Whole saliva was assessed for flow rate and for concentrations of sodium, potassium, chloride, calcium and phosphate. In addition, parotid and SM-SL secretion were assessed for concentrations of total protein, hexosamine, sialic acid, lactoferrin and salivary IgA and for activities of amylase, lysozyme and salivary peroxidase. During treatment with the angiotensin converting enzyme inhibitor captopril, the secretion rates tended to increase for unstimulated and paraffin-chewing stimulated whole saliva and for parotid secretion. For salivary composition, no alterations were observed in any of the collected secretions.

Adolescent↗

PubMed1995

Effect of an antibacterial varnish on mutans streptococci in plaque from enamel adjacent to orthodontic appliances.

The effect of an antibacterial varnish (Cervitec) on the levels of mutans streptococci in plaque adjacent to bonded orthodontic brackets was evaluated in 18 children using a split-mouth technique with a placebo varnish control. The test varnish contained 1% chlorhexidine and 1% thymol as active ingredients. Both varnishes were applied on four occasions during a 3-month period, and plaque was subsequently collected between 1 week and 6 months after the onset of treatment. All teeth involved in the study were carefully examined and clinically assessed for enamel demineralization prior to onset of the fixed appliances and immediately after debonding. The results showed a more frequent growth of mutans streptococci in the dental plaque collected from placebo-treated quadrants as compared with the test quadrants on all sampling occasions. The proportion of mutans streptococci within the plaque microflora was significantly (p < 0.05-0.01) lower on the test sides than on the opposite sides at the 1-week and 1-month examinations. The incidence of incipient enamel lesions around the brackets and along the gingival margin was generally low, and no differences were found between the test and placebo varnish treated quandrants at the time of debonding. The results suggest that mutans streptococci in plaque from orthodontic patients can be suppressed effectively by topical applications of an antibacterial varnish.

Adolescent↗

PubMed1995

Influence of xylitol in dentifrice on salivary microflora of preschool children at caries risk.

The aim was to study whether the use of a xylitol-containing dentifrice could affect the number of mutans streptococci and lactobacilli in preschool children with medium and high initial salivary counts. After screening 147 healthy preschool children, 3-6 years of age, 70 were selected and randomly assigned into two groups for 3-month's use of either a xylitol (9.7%) or a non-xylitol-containing fluoride dentifrice. The parents were trained to brush the teeth of their children twice daily in a standardized manner and the study was carried out double blind. Bacterial levels at screening and after 3 months were enumerated with aid of chair-side methods. No significant differences in mutans streptococci levels or lactobacilli counts after 3 months were obtained, either in comparison to baseline or between the groups. About 50% of all children exhibited unchanged bacterial scores at the end of the test period but more children in the xylitol group disclosed reduced scores of salivary mutans streptococci compared with the non-xylitol group (38% vs 16%). The results suggest that the dose level achieved by using this xylitol-containing dentifrice in preschool children, did not provide sufficient antibacterial action to suppress caries associated microorganisms in the saliva of those with high initial counts.

Child↗

PubMed1994

Use of the strip mutans test in the assessment of caries risk in a group of preschool children.

The purpose of this study was to evaluate the use of a chair-side test involving a count of salivary mutans streptococci (the Strip mutans test) in the assessment of caries risk in a group of preschool children living in an area with a low caries prevalence. A group of 528 4-year-old children were randomly allocated to a study or a control group. In the study group, the baseline microbial data, together with clinical findings of past caries experience, were used for caries risk assessment and for planning subsequent preventive treatment. All children were examined at baseline and after 2 years. Caries experience was assessed according to WHO criteria. There was no difference in caries experience between the study group and the control group at baseline. Within the study group, caries increment was positively correlated (P < 0.01) with the number of mutans streptococci in saliva at baseline, and children assessed 'at risk' at baseline (Strip mutans score > or = 2 and/or > or = 1 dmfs) developed more new lesions than those considered as 'low risk' (mean dmfs 2.6 v 0.9; P < 0.05). The sensitivity and specificity of this combined clinical and microbial caries risk selection were 67% and 75%, respectively, disease being defined as an increment of at least one carious lesion over the 2-year period. In both groups, 50% of the children remained caries inactive during the study. The mean caries increment was, however, lower in the study group than in the control group (mean dmfs 1.7 v 2.1) but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1994

Effects of the beta-adrenoceptor antagonists atenolol and propranolol on human unstimulated whole saliva flow rate and protein composition.

The effects of 1-wk medication with two beta-adrenoceptor antagonists on unstimulated whole saliva flow rate and protein composition were evaluated in 11 healthy young men in a randomized, double-blind, placebo-controlled, cross-over study. Unstimulated whole saliva was collected before each treatment period and then again after 7 days. The saliva was assessed for flow rate, total protein, and hexosamine and sialic acid concentrations and for amylase activity. No significant effect on saliva secretion rate was found. A statistically significant reduction of salivary total proteins was registered during atenolol medication. The amylase activity decreased significantly during treatment with both atenolol and propranolol. Significant changes of the calculated ratios of sialic acid/hexosamine and hexosamine/total protein indicated an alteration in glandular protein synthesis after atenolol treatment.

Adult↗

PubMed1994

Effects of the beta-adrenoceptor antagonists atenolol and propranolol on human parotid and submandibular-sublingual salivary secretion.

The aim of the study was to evaluate the effects of a beta 1-selective (atenolol 50 mg q.d.) and a non-selective (propranolol 80 mg b.i.d.) beta-adrenoceptor antagonists on human stimulated parotid and submandibular-sublingual (SM-SL) gland secretion. A randomized double-blind, placebo-controlled cross-over ("Latin square") design was used in 19 healthy male volunteers. Stimulated parotid and SM-SL saliva were sampled immediately before and 7 days after the start of each treatment period. Stimulation of salivary secretion was achieved by use of a 3% citric acid solution. Plasma concentrations of propranolol and atenolol were determined from blood samples. The salivary secretion of both glands was assessed for flow rate, amylase, lysozyme, and salivary peroxidase activity and for concentrations of total protein, hexosamine, sialic acid, Ca2+, Cl-, K+, Mg2+, Na+, and PO4(3-). In both parotid and SM-SL secretions, the total protein and phosphate concentrations and amylase activity were significantly decreased during the two active treatment periods. In SM-SL gland secretion, there were significant changes in potassium and calcium concentrations during active treatment as compared with baseline, with potassium showing a decreased and calcium an increased concentration. During atenolol treatment, salivary peroxidase activity decreased significantly in SM-SL secretion. In parotid secretion, the hexosamine/total protein ratio decreased and the sialic acid/hexosamine ratio increased during atenolol treatment, which may indicate an effect on protein synthesis. No significant effects on salivary secretion rates were disclosed.

Adult↗

PubMed1994

L(+)-lactic acid production in plaque from orthodontic appliances retained with glass ionomer cement.

The lactic acid production in suspensions of plaque collected adjacent to orthodontic brackets retained with a glass ionomer cement (GIC), or a resin-based composite was investigated using a split-mouth technique. Forty-eight-hour-old plaque was collected at 3, 8, and 28 days, and 3 months after the onset of orthodontic treatment. Acid fermentation was induced by glucose and the L(+)-lactic acid concentrations were determined enzymatically after a 30-minute incubation period. Significantly (P < 0.05) lower levels of lactic acid were found in plaque from GIC-retained brackets compared with the composite controls at the 28 days and 3 months sampling occasions, respectively. The results suggest that the use of GIC as a bonding agent in orthodontics can be beneficial for patients assessed at risk of caries development.

Acrylic Resins↗

PubMed1993

Prediction of caries incidence in schoolchildren living in a high and a low fluoride area.

A salivary mutans streptococci test and past caries experience were used as predictors for caries increment in a 3-yr study comprising 655 12-yr-old schoolchildren from two areas with contrasting levels of fluoride in the drinking water. The mean caries (DMFS) increment was similar in both groups during the study period, but a significantly (P < 0.05) higher incidence of approximal enamel lesions was registered in children from the high fluoride area. In both groups, a statistically significant (P < 0.05-0.001) positive relationship between salivary mutans streptococci score and/or past caries experience at baseline on one hand and caries increment during the study period on the other was established. The past caries experience was the most powerful predictor of caries risk in both the low fluoride and the high fluoride area. The sum of the sensitivity and specificity was somewhat higher in the low fluoride area (138%) compared to the high fluoride area (123%). The salivary bacterial enumeration used alone or in combination with past caries experience as well as past approximal caries experience were less useful as predictors in both groups. The present findings indicate that the natural fluoride exposure has a limited influence on caries risk assessment and the caries predictive ability of the salivary bacterial test and past caries in populations with a low level of disease.

Analysis of Variance↗

PubMed1993

Fluoride concentration in plaque adjacent to orthodontic appliances retained with glass ionomer cement.

The fluoride concentrations in dental plaque adjacent to orthodontic brackets retained with a glass ionomer cement (GIC) or a resin-based composite were investigated using the split-mouth technique. 48-hour plaque was collected at 3, 8, 28 days and 6 months after the onset of orthodontic treatment. The fluoride content of the plaque samples was determined after a microdiffusion procedure with a fluoride-sensitive electrode. Significantly (p < 0.001-0.05) elevated concentrations of fluoride were found in the plaque samples collected adjacent to GIC-retained brackets compared to plaque sampled from composite-retained brackets on all sampling occasions. The results suggest that GIC-bonded brackets in orthodontic treatment may act as local long-term fluoride-releasing devices.

Acrylic Resins↗

PubMed1992

Caries associated microflora in plaque from orthodontic appliances retained with glass ionomer cement.

The caries associated microflora in dental plaque adjacent to orthodontic brackets retained with a glass ionomer cement (GIC) and a resin based composite was investigated using the split-mouth technique. 3, 8, and 28 days after the onset of the appliances, 48-h-old plaque was sampled. An increasing prevalence of mutans streptococci and lactobacilli in plaque from both retaining materials was found. A tendency to colonize more frequently around the composite retained brackets was noticed for both types of bacteria. The proportion of mutans streptococci in relation to the total viable count was significantly higher in plaque samples from composite retained brackets compared to GIC retained 1 month after onset of treatment. The results suggest that a less caries inducing microflora may develop when GIC is used as luting agent in orthodontic dentistry.

Adolescent↗

PubMed1992

Pit and fissure sealing and mutans streptococci levels in saliva.

The effect of preventive pit and fissure sealants with a resin-based material on the number of salivary mutans streptococci was evaluated in 46 healthy 12-year-old school children (F group) with medium or high counts during a 1-year study period. As controls served 33 children of the same age with the same bacterial levels at baseline (C group) and 55 children with low levels (L group). Caries prevalence and incidence were registered clinically and radiographically. Sealing of all accessible pit and fissures was carried out in the F group with a light-cured Bis-GMA sealant. Bacterial levels at baseline and 3, 6, 12 and 52 weeks after treatment were estimated with a chairside method. The results disclosed a significant (P < 0.05) drop in the number of salivary mutans streptococci in the F and C groups at all sampling occasions compared to baseline. There were however no differences between the groups during the study period. Both the caries prevalence and incidence were significantly (P < 0.05) higher in F and C groups when compared to the L group. The results suggest that preventive pit and fissure sealing with a resin based material does not affect salivary mutans streptococci levels.

Child↗

PubMed1991

Mutans streptococci in saliva and interdental spaces after topical applications of an antibacterial varnish in schoolchildren.

The effect of a chlorhexidine-containing varnish on the levels of mutans streptococci in saliva and in interdental spaces was investigated in 33 15-year-old schoolchildren. Each child was treated with an active (1% chlorhexidine; 1% thymol) and a placebo varnish preparation following the split-mouth technique. The varnishes were applied twice in small amounts into upper interdental areas with a 2-d interval. Mutans streptococci in saliva and interdental plaque was sampled and enumerated during 3 months. The results showed an immediate reduction of the number of interdental mutans streptococci on both test and placebo side after the varnish applications. The levels, however, were significantly lower in the test quadrants compared with the placebo-treated sides after 8, 30 and 90 d. Thus, the findings indicate a slower recolonization in interdental spaces treated with the active preparation. The levels of mutans streptococci in saliva were significantly reduced 1 and 3 months after varnish treatment, suggesting a long-term effect of the antibacterial varnish.

Adolescent↗

PubMed1991

Salivary mutans streptococci and caries prevalence in 8-year-old Swedish schoolchildren.

The aim of this study was to obtain cross-sectional information about the quantitative distribution of salivary mutants streptococci assessed with a clinically applicable microbiological method and the relation to dental caries in young schoolchildren. A total of 355 8-year-old children were examined for the presence and number of mutants streptococci in saliva by a specially prepared strip, the "Strip-mutans" method, cultivated in a selective broth. The strips were first visually examined and grouped by aid of a templet provided by the manufacturer and thereafter transferred to a laboratory for enumeration of colony forming units (CFU) with aid of a stereomicroscope. Caries scores were obtained from the dental records. Mutans streptococci were identified in 70% of all children. 46% were free from the bacterium or harboured low levels (0-10 CFU) while high levels (greater than or equal to 500 CFU) were found only in 6% of the material. Strong positive correlations (p less than 0.001) were found between different levels of mutans streptococci infection and the caries experience in both the primary (dmfs) and the permanent (DMFS) dentition. A statistically significant correlation between the direct examination and the microscopic enumeration was disclosed (r = 0.84). The bacterial culturing technique used in this study proved to be practical and reliable and thus useful in clinical routines of pediatric dentistry.

Child↗

PubMed1990

Mutans streptococci in saliva and dental caries in children living in a high and a low fluoride area.

The aim of this study was to obtain information about the quantitative distribution of salivary mutans streptococci and the relation to dental caries in children with contrasting levels of natural water fluoride. A total of 698 schoolchildren aged 12 yr were selected from areas with high (1.2 ppm) or low (0.1 ppm) fluoride concentration in the drinking water. They were all examined for the presence and number of mutans streptococci in saliva by a specially prepared plastic strip, the "Strip mutans" method, cultivated in a selective broth. Data on the caries experience were obtained from the dental records and from bite-wing radiographs. Mutans streptococci were identified in 82% of all children with no difference between the two areas. The number of mutans streptococci was however significantly (p less than 0.05) lower among the children from the high fluoride area than those from the low fluoride area. Children with no detectable or low levels (0-10 CFU) of mutans streptococci had less caries experience than children with moderate or high levels (11- greater than 500 CFU) in both areas investigated.

Child↗

PubMed1990

Diurnal fluoride concentration in whole saliva in children living in a high- and a low-fluoride area.

Salivary fluoride concentrations were investigated in 12-year-old children living in areas with low (0.1 ppm) or high (1.2 ppm) fluoride concentration in the drinking water. Unstimulated whole saliva was collected from 27 children from the respective areas every 2nd hour for 46 h except during sleep. The mean salivary fluoride concentration was 0.32 +/- 0.013 mumol/l (n = 419) in the low-fluoride (LF) area and 0.87 +/- 0.047 mumol/l (n = 401) in the high-fluoride (HF) area. No significant rhythm could be found for the diurnal variations in the mean or individual salivary fluoride concentrations. However, in the HF area the individual salivary fluoride concentrations fluctuated widely and randomly.

Analysis of Variance↗

PubMed1990

Salivary fluoride concentrations in children with glass ionomer cemented orthodontic appliances.

Salivary fluoride concentrations were determined in 10 children (mean age 12.0 years) undergoing fixed orthodontic therapy. The orthodontic appliances, a minimum of 4 bands and 8 brackets, were cemented with a glass ionomer cement. Unstimulated whole saliva was collected 4 times a day before (baseline value) and at 1, 7, 14 and 28 days after cementation. The samples of saliva were centrifuged and the supernatants were analyzed with a fluoride-sensitive electrode. At baseline, the mean salivary fluoride concentration was 0.85 mumol/l. There was a significant increase during the day after cementation (1.88 mumol/l). After 7, 14 and 28 days, salivary fluoride levels were slightly elevated, but not statistically different from the baseline values. The ingested fluoride dose during the 1st day was estimated to be 0.02 mg. It is concluded that in orthodontic treatment with fixed appliances, a slow release of fluoride from glass ionomer cements could exert a local cariostatic effect on adjacent caries-susceptible enamel.

Adolescent↗

PubMed1990

Cryosurgical treatment of mucocele in children.

Cryosurgery of superficial mucoceles located in the lower lip of eight children is reported. The treatment did not require administration of local anesthetics and was easily performed and well-tolerated even by small children. Healing proceeded uneventfully in all patients. No recurrence during a 1-year follow-up period was observed. Cryosurgery proved to be an effective and essential tool in the management of mucocele in children.

Child↗

PubMed1989

Mutans streptococci and lactobacilli in saliva from children with insulin-dependent diabetes mellitus.

The quantitative distribution of mutans streptococci and lactobacilli in saliva of insulin-dependent diabetic children was compared with a group of healthy children and related to the metabolic control of the disease. The study group, consisting of 94 boys and girls (age 4-19) with type 1 diabetes was matched by sex and age with a non-diabetic control group. Stimulated whole saliva was collected and flow rate, buffer capacity and the levels of mutans streptococci and lactobacilli were analysed in all children. In the diabetic group, total salivary proteins and glucose content of saliva were determined. Data on caries experience were recorded from the dental cards of all children. There were no difference in the distribution or number of mutans streptococci between the groups, but significantly (p less than 0.05) lower levels of lactobacilli were found among the diabetic children. The number of lactobacilli was positively correlated (p less than 0.05) to glucose concentration in saliva. There was no difference in the prevalence of caries between the groups. The present findings suggest that the dietary treatment of young insulin dependent diabetics gives rise to a reduced number of lactobacilli in saliva but does not affect the mutans streptococci.

Adolescent↗