Comparison of the severity of caries attack in permanent first molars in Iraqi and Sudanese schoolchildren

Severity of caries attack of the permanent first molars was investigated on two population groups of Arabian origin, namely 1617 Iraqi and 725 Sudanese primary schoolchildren ranging in age from 6 to 12 years. The results showed a higher DMF rate in the Iraqis in all the age groups studied, reaching a maximum of 83% at age 11, whereas the maximum level was 60% in Sudanese children at age 10.     

Influence of salivary macromolecules and fluoride on enamel lesion remineralization in vitro

The aim of this study was to investigate the influence of salivary macromolecules on enamel lesion remineralization in the presence or absence of fluoride. Paraffin-stimulated whole saliva was centrifuged, and the supernatant was dialyzed in 1,000 molecular-weight cutoff dialysis tubes, first against a phosphate buffer and then against a mineral solution containing Ca and phosphate. Artificial subsurface lesions of human enamel, created in pH 4.5 acetate buffer, were remineralized for 28 days in 4 remineralizing solutions: group C--mineral solution as a control; group S--mineral solution + dialyzed saliva; group F--mineral solution + 1 ppm F; group SF--mineral solution + dialyzed saliva + 1 ppm F. Changes in relative mineral concentration in the lesions were assessed by transverse microradiography. The results showed statistically significant mineral gains in the lesion body in groups C (DeltaZ = 3,254 +/- 1,562% x microm) and SF (DeltaZ = 2,973 +/- 1,349% x microm), but not in groups S (DeltaZ = 5,192 +/- 1,863% x microm) and F (DeltaZ = 4,310 +/- 1,138% x microm) compared with the baseline group (DeltaZ = 5,414 +/- 461% x microm). It was also found that the mineral density at the surface layer in group F (75.0 +/- 15.7%) was greater than that in the baseline group (30.1 +/- 12.3%) with statistical significance, but not in group SF (39.9 +/- 16.5%). It was concluded that the macromolecules inhibited lesion remineralization fundamentally but that these molecules, in the presence of fluoride, seemed to play an important role in the continuation of remineralization by reducing mineral gains at the surface layer.     

An in vivo investigation of associations between saliva properties, caries prevalence and potential lesion activity in an adult UK population

OBJECTIVE: To investigate associations between prevalence and activity of intra-oral incipient, carious lesions and salivary properties tested using the Saliva Check kit (GC Corp., Belgium). METHODS: With ethical approval, 58 subjects with >16 teeth underwent clinical/radiographic examination. Conventional decayed, missing, filled teeth/decayed, missing, filled surfaces (DMFT/DMFS) indices and a more recently developed visual index described by International Caries Detection and Assessment System (ICDAS) were used to ascertain caries prevalence. Potential lesion activity was scored using an Ekstrand visual index. Saliva properties tested included hydration, resting pH, stimulated flow and buffering capacity. Spearman's rank correlation was used to analyse data. RESULTS: No saliva parameters correlated significantly with DMFT/DMFS caries prevalence scores (D3 threshold). The resting pH correlated negatively and significantly with the total number of lesions (r=-0.267, p=0.043), with ICDAS scores >1 (r=-0.333, p=0.011) and with mild lesions (r=-0.263, p=0.046). A negative correlation was found between saliva buffering capacity and the potential activity of moderate lesions (ICDAS 3 and 4; r=-0.227, p=0.035). CONCLUSIONS: There appeared to be a correlation between the resting pH of saliva and the prevalence of early lesions as well as the saliva buffering capacity and the potential lesion activity of moderate lesions. A difference was shown between lesion prevalence calculated using traditional DMFT(S) D3 versus the ICDAS D1 thresholding.     

SEM analysis of sealant penetration in posterior approximal enamel carious lesions in vivo

PURPOSE: To study the microstructure of sealant penetration in the enamel of in vivo sealed approximal noncavitated incipient caries lesions with and without a preceding bonding step. MATERIALS AND METHODS: A total of 26 proximal noncavitated caries lesions were sealed in vivo, using a sealant in 13 premolars with orthodontic indication of extraction. Each tooth was randomly assigned to mesial or distal surface application of a sealant in the lesion area and in surrounding sound enamel, with or without a bonding system. Four groups were analyzed: a nonbonding group in the lesion area (NBL); a nonbonding group in sound enamel (NBS); a bonding group in the lesion area (BL) and a bonding group in sound enamel (BS). The premolars were extracted after two weeks. All sealed areas were cut and demineralized with 37% hydrochloric acid for 24 h. For each group, the resin tags were observed and measured by scanning electron microscopy. RESULTS: The lesion areas showed a very irregular resin network with twisted and curved tags in contrast to the sound enamel where a regular etching pattern was observed. The length of resin tags in microns for each group (mean +/-SD) was: NBG-L = 4.19 +/- 1.59; NBG-S = 5.49 +/- 2.49; BG-L = 4.57 +/- 1.99; and BG-S = 4.21 +/- 1.87. The differences between the groups were not statistically significant (p = 0.34). Conclusion: The use of a bonding system prior to the application of a pit and fissure sealant on both lesion and sound enamel areas does not increase the resin penetration length under non-contaminated conditions.     

Synchrotron x-ray microtomographic investigation of mineral concentrations at micrometre scale in sound and carious enamel

Synchrotron X-ray microtomography (XMT) was used to measure the linear attenuation coefficient (LAC) for 1.9-microm sidelength voxels within approximal brown spot lesions and sound human enamel. XMT demonstrated three-dimensional features, notably sheets with approximately 30 microm periodicity having low LAC, identified as regions of demineralization corresponding to Retzius lines. Quantitative three-dimensional measurements of mineral concentration, derived from LAC with assumption of a single model composition, were consistent with previous measurements of sound and carious enamel from microradiographic projections. The uncertainty in measurements of mineral concentration and mineral fraction volume was investigated by modelling enamel with a range of composition and component densities. This analysis showed that, although mineral concentration can be determined from LAC with an error of <0.2 g cm(-3), the variation in pore fraction volume within caries lesions cannot be reliably determined from X-ray attenuation measurements alone.     

Influence of in vivo formed salivary pellicle on enamel erosion.

This study assessed the protective effect of the salivary pellicle formed in vivo during 24 h or 7 days against demineralization of bovine enamel caused by citric acid. In addition, the influence of acid treatment on the behavior of the pellicle was investigated. Enamel specimens with and without in vivo pellicles were immersed in citric acid (0.1, 1.0%) over 30, 60, and 300 s, and processed for scanning (SEM) and transmission electron microscopy (TEM), as well as for measurement of surface microhardness (SMH). Specimens coated with the in vivo formed pellicles revealed less extensive erosive demineralization of the enamel surface compared to uncovered enamel specimens. SEM analysis and SMH results did not indicate distinct differences between erosive surface alterations on enamel slabs covered with 24-hour pellicles and on those covered with 7-day pellicles. TEM analysis showed that the pellicle layer was dissolved in part from the enamel surface due to acid exposure. However, pellicle residues could be detected by TEM in all specimens, even after 5-min exposure to 1.0% citric acid. It is concluded that the in vivo salivary pellicle can resist the acidic action to some extent and provides protection to the underlying enamel surface against erosive destruction caused by short-term action of citric acid.     

Visual and tactile assessment of arrested initial enamel carious lesions: an in vivo pilot study

Accurate and reliable assessment of caries activity is important for determining appropriate treatment needs. The aim of this pilot study was to determine whether dentists could differentiate between the appearances (visual and tactile) of lesions inactivated by regular professional oral hygiene and those control lesions which were not cleaned (active). After a 3- to 4-week study period involving 10 children, with 4 similar carious lesions each, it was found that dentists were not able to reliably and reproducibly determine the subtle visual and tactile differences between active and inactive enamel lesions from a one-off clinical examination.     

The prevalence and aetiology of molar-incisor hypomineralisation in a group of children in Istanbul

AIM: To our knowledge, the prevalence and aetiology of molar-incisor hypomineralisation has not been discussed nor investigated in Turkish children in Istanbul. Therefore the aim of the present study is to investigate the prevalence and aetiology of MIH in a group of children in Istanbul. DESIGN: Between April and July 2007, a retrospective clinical study was initiated at the Dept. of Paediatric Dentistry, School of Dentistry, Yeditepe University, Istanbul, Turkey. A total of 147 children aged 7-9 years visiting our clinic were examined by two calibrated paediatric dentists (kappa: 0.89). The examiners used the criteria for the diagnosis of demarcated opacities, post-eruption breakdown, atypical restorations, and extracted PFMs due to MIH developed by Weerheijm et al. RESULTS: In the present study, prevalence of MIH was 14.9%. Of the 22 children affected with MIH, 17 (77.2%) had only demarcated opacities, but no breakdown or atypical restorations. Regarding diseases in the first 3 years of life, 55% of MIH and 19.4% of non-MIH children had a disease history. 27% of MIH children had suffered from upper and lower respiratory tract infections including bronchitis. This was significantly different from non-MIH children (p<0.001). CONCLUSION: MIH was common among a group of 7-9 years old children, Istanbul.     

Prevalence of geographic and plicated tongue in 6090 Iraqi schoolchildren

Abstract The prevalence of geographic and plicated tongue among 6090 Iraqi schoolchildren was determined according to age and sex. Geographic tongue was observed in 4.3% of the population and plicated tongue in 2.6%. Significant sex difference was found only in children with plicated tongue. The prevalence rates varied irregularly with age in both sexes for both tongue anomalies and although significant differences were found between the ages, a steady increase or decrease was not clear, which could be due to the short span of age used in this investigation. The only significant association found was between geographic and plicated tongue in males, which may indicate a genetic linkage between the two conditions.     

The occurrence of blood group substances (A, B, H, Le-a, Le-b) in salivary glands and salivary gland tumors. An immunohistochemical investigation

The distribution of blood group substances A, B, H, Le-a and Le-b in normal and neoplastic salivary gland tissue was evaluated by means of immunohistochemistry. The serological ABH blood group status of one third of the patients was known. Lewis blood group and secretory status were not known. In normal tissue, expression of blood group antigens corresponded to the serological blood group. Blood group substance H was present in almost every gland, regardless of the serological blood group. In submandibular glands, Le-b was rather selective for mucous acini. In tumors, a relationship of blood group expression to a glandular pattern and a high differentiation could be observed. Blood group substances were expressed at a high level in benign and highly differentiated malignant tumors. In poorly differentiated malignant tumors, they were mostly absent. Blood group expression evaluation could be of value in establishing the level of functional differentiation in salivary gland tumors.