Biomedical subjects

M Bizhang

Publications and source records attributed to M Bizhang.

6 recordsLinked to original sources

PubMed2004

Levels of parotid and submandibular/sublingual salivary immunoglobulin A in response to experimental gingivitis in humans.

Salivary secretory IgA (s-IgA) is considered to act as an important first line of defense mechanism in the oral cavity. It has therefore been suggested that an increased antigenic load would induce an increase in salivary IgA production. This study investigated the pure glandular levels of salivary IgA in parotid and submandibular/sublingual (SM/SL) saliva during plaque accumulation leading to experimental gingivitis. Starting from regular oral hygiene, 14 healthy, nonsmoking men refrained from all oral hygiene measures for 12 days. On days -2, 0, 3, 6, and 12 a plaque index, a bleeding index, and unstimulated and stimulated saliva from the parotid and the SM/SL glands were measured. Salivary IgA was quantified using a sandwich ELISA. All subjects developed gingivitis as measured by a bleeding index. Compared to baseline the salivary flow rate was increased on day 12. Regarding the secretion rate of IgA there was a statistically significant increase in stimulated parotid saliva but not SM/SL saliva compared to baseline after 6 and 12 days without oral hygiene. No significant changes were observed for the concentration of IgA during the trial. Thus, in healthy subjects with regular oral hygiene the development of plaque induced gingivitis is associated with increased salivary gland output and increased total IgA output levels in stimulated parotid saliva but not in SM/SL saliva.

Adult↗

PubMed2001

The effect of a preventive program, including the application of low-concentration fluoride varnish, on caries control in high-risk children.

The aim of this 2-year prospective randomized clinical study was to evaluate the efficacy of a prevention program for schoolchildren with high caries risk. A sample of 419 subjects was divided into a test (T, n = 259) and control group (C, n = 160). Four times a year, the test group received professional tooth-cleaning and application of a 0.1% fluoride varnish as well as motivation and instruction in oral hygiene. The control group received only oral hygiene instruction and took part in supervised toothbrushing once a year. At baseline and after 2 years, the D3,4MFS and the incipient lesions (D1,2) were recorded. After 2 years, 318 subjects (T = 187, C = 131) were included in the data analysis. The baseline D1,2 was 6.18 (T) and 5.50 (C), the D3,4MFS 2.13 (T) and 2.08 (C), respectively. No statistically significant difference was found for the baseline values. At the final examination, the D1,2 increment was 3.96 in the test and 6.53 in the control group, showing a statistically significant difference (P < 0.001). No such difference was found for the D3,4MFS increment (T: 2.22; C: 2.61). The results indicate that it might not be possible to prevent cavities in high caries risk children by means of the described program.

Cariostatic Agents↗

PubMed2001

[Effective of preventive programs on oral hygiene of adults and school children].

The improvement of dental hygiene is considered to be one of the most important measures in dental health education. Hence, it was the aim of the present study to investigate the influence of two similar preventive programmes on oral hygiene performed in adults and schoolchildren. In the adult study, the oral hygiene indices PI (Quigley-Hein) and API (Lange) could be significantly improved after six months by an individualized preventive programme performed every three months. Besides repeated instructions and motivations in oral hygiene, the programme included professional toothcleaning. In contrast, nine-year old schoolchildren showed no improvement in the oral hygiene indices PI and PBI (Mühlemann and Son) after applying a similar programme over three years. For the PI, even a deterioration from 1.86 at the beginning of the study to 2.65 at the final examination was seen. Other authors were more successful by applying a programme without professional toothcleaning but with inclusion of the parents. It is therefore concluded that children should be educated to oral self-care by including their parents and by taking their status of psychological development into account.

Adult↗

PubMed2001

Effectiveness of mechanical tongue cleaning on oral levels of volatile sulfur compounds.

BACKGROUND: Mechanical tongue cleaning may be an effective method for decreasing oral levels of volatile sulfur compounds, or VSC, and oral malodor. The authors conducted a study to compare the effectiveness of a specially designed tongue cleaner (One Drop Only Tongue Cleaner, One Drop Only, Berlin), a tongue scraper and a toothbrush in reducing oral VSC levels. METHODS: In this balanced, crossover study, 30 subjects had four morning appointments each with a waiting period of one week between appointments. At each appointment, a dental professional performed a single standardized tongue cleaning procedure using one of the cleaning tools. The authors monitored the subjects' oral VSC values using a portable sulfide monitor until their baseline VSC values were reached. RESULTS: The baseline values showed no significant difference between the three groups. The tongue cleaner and the tongue scraper (42 percent and 40 percent, respectively) reduced oral VSC levels more than the toothbrush (33 percent) did. Reduced VSC values could be detected significantly longer after using the tongue cleaner than after using the tongue scraper or the toothbrush. The authors, however, could not detect a significant VSC reduction for more than 30 minutes in any of the subjects. CONCLUSIONS AND CLINICAL IMPLICATIONS: The tongue cleaner, a combination brush and scraper, was slightly more effective in reducing oral VSC levels than were the tongue scraper and a regular toothbrush. Because of the limited duration of the effect, however, the clinical efficacy on the reduction of oral malodor remains questionable.

Analysis of Variance↗

PubMedDate not supplied

Differences in the salivary glycan pattern between children with high and low caries susceptibility.

Interactions between bacterial adhesins of lectin type and the oligosaccharide part of immobilised glycoconjugates on the tooth surface are involved in the specific colonisation of teeth. The specificity of the adhesion process is determined by the carbohydrate specificity of the bacterial lectins and the availability of the corresponding glycosylation pattern. On the other hand the same carbohydrate structures can specifically prevent the binding of bacteria by competitively blocking their adhesion, if sufficient amounts of this distinct carbohydrate structure are available in the secretion. Since carbohydrate binding receptors are also involved in the colonisation of tooth surfaces by cariogenic bacteria, it has been suggested that the architecture of the oligosaccharide portion of soluble glycoconjugates in saliva may play an important role as a constitutional host defence factor in the aetiology of dental caries. Characterising the availability of distinct carbohydrate patterns in saliva by using a pattern of well-described lectins in a competitive lectin inhibition assay we show that in children of a population-based sample a high caries susceptibility is associated with a reduced binding inhibition against the lectin peanut agglutinin (PNA). PNA is specific for the presence of terminal galactosyl residues and binds to the same O-glycan fractions as a surface lectin from Streptococcus mutans. The data suggest that a reduced availability of glycosylation patterns of galactosyl residues detected by the lectin PNA may act as an additional host-derived factor for an increased caries susceptibility.

Acetylgalactosamine↗

PubMedDate not supplied

A novel in vitro microbial-based model for studying caries formation--development and initial testing.

We report on the development and the initial testing of a new microbial-based caries model. Specimens were fixed on a rotating mount within a reaction chamber hermetically surrounded by a sterilised glove box. A cariogenic environment was obtained by inoculation with Streptococcus mutans (ATCC 25175) combined with a continuously repeating supply of sucrose solution, trypticase soy broth and artificial saliva applied by dripping. Twenty-five caries-free upper premolars were used. The mesial parts of the occlusal fissures had been sealed with a resin-based fissure sealant (test group 1). To produce marginal gaps, the distal parts had been moistened with saliva before resin application (test group 2). Five teeth served as control and were exposed to all fluids under sterile conditions before being removed from the system after 7 days. Test specimens were infected with S. mutans and were incubated for another 14 days. No unintentional contamination occurred during the 3-week period of operation. Demineralizations were evaluated by using confocal laser scanning microscopy. Only the test specimens showed clearly visible signs of biofilm formation and caries-like lesions. The mean primary lesion depth did not differ significantly between test groups. Wall lesion depths and surface areas of demineralizations underneath the fissure sealants were significantly higher in test group 2. Thus, our model allows the simultaneous production of primary and secondary caries-like enamel lesions in a considerable number of specimens and facilitates the possibility to manipulate and transfer them without necessarily terminating the experiment, opening new possibilities for in vitro caries research.

Bicuspid↗