Biomedical subjects
S al-Khateeb
Publications and source records attributed to S al-Khateeb.
Laser fluorescence quantification of remineralisation in situ of incipient enamel lesions: influence of fluoride supplements.
The aims of this study were to test the laser fluorescence method for quantification of remineralisation in situ of enamel with incipient lesions and to evaluate the enhancement of remineralisation by fluoride (F) supplements when a F dentifrice was used on a regular basis by healthy young subjects. Enamel samples were cut from extracted premolar teeth with the natural surface kept intact, and subjected to a pH-cycling system to produce subsurface demineralisation in vitro. The enamel blocks were then inserted into composite holders bonded to the buccal surfaces of both upper first molars of 12 panelists. Each panelist participated in 3 separate experiments in a randomised order; each lasted for 5 weeks with washout intervals of 2 weeks between experiments; experiment 1: F dentifrice (0.145% F as NaF) only; experiment 2: F dentrifice + F lozenges (0.25 mg F x 6/day); experiment 3: F dentifrice + F chewing-gum (0.25 mg F x 6/day). Fluorescence radiance was measured before, during, and after in vitro demineralisation, and once a week during the in situ experimental periods. The enamel samples were then sectioned and analysed with transverse microradiography (TMR). Anova and Pearson correlation coefficient were used for the statistical analysis. At the end of the 5-week in situ periods, fluorescence radiance had been regained to a level of 80-100% of the value before in vitro demineralisation, indicating remineralisation of the enamel samples. There were no differences in the fluorescence radiance gain between the 3 different F exposures. However, there was a statistically significant time trend (p < 0.001), and a highly significant linear dependence (p < 0.001) between the final measurements obtained with the laser fluorescence method (LAF) and the data obtained from TMR, r = 0.76. It was concluded that: (1) with the sensitive LAF method it was possible to register the small changes in the enamel week by week during in situ remineralisation: (2) when F dentrifice was used regularly, F supplements such as F lozenges or F chewing-gum did not significantly enhance the in situ remineralisation of incipient enamel lesions in healthy, young adults with normal salivary flow.
Quantification of formation and remineralization of artificial enamel lesions with a new portable fluorescence device.
Quantitative laser fluorescence has been reported as a useful method for the non-destructive in vitro and in vivo diagnosis of early enamel caries. A portable system for intraoral use has been developed with a new light source and filter system replacing the laser light to facilitate clinical application. This new device was validated with microradiographic and chemical analyses for assessment of mineral changes in enamel during lesion formation and remineralization in vitro and compared with the laser light equipment. A significant correlation was found between fluorescence changes and mineral loss: r = 0.79 (laser system) and r = 0.84 (portable lamp system). The correlation between the two fluorescence methods was r = 0.93. The portable fluorescence device seemed to be a promising new tool for reproducible and sensitive assessment of the severity of incipient enamel lesions.
Mesiodistal crown diameters of permanent teeth in Jordanians.
Mesiodistal crown diameters were measured from dental casts of the permanent teeth of 198 Jordanians (86 males and 112 females), aged 13.4-19.1 years. The differences in the crown diameters between the right- and left-hand sides of the dental arch were not significant, suggesting that either right- or left-side measurements could be taken to represent the tooth size of the study population. Males had significantly larger teeth than females, ranging from p < 0.05 for the incisors to p < 0.001 for the first molars. In both sexes, the maxillary lateral incisors showed the greatest variability [coefficient of variation (CV) 8.8%] and the first molar the least (CV 5.8%) in mesiodistal diameter. Canines displayed greater sexual dimorphism in crown size than any other tooth class. The cumulative tooth widths of males exceeded those of females by a sum of 3.1 mm in the maxilla and 3.6 mm in the mandible. These differences were statistically significant (p < 0.01). Comparisons of the mesiodistal crown diameters between population groups showed that Jordanians have tooth sizes close to those of Iraqis, but significantly larger than those of Yemenite-Jews, Caucasians and Chinese.
Monitoring the caries process. Optical methods for clinical diagnosis and quantification of enamel caries.
Early detection of a caries lesion would enable the dentist, by using effective prophylactic measures, to enhance remineralization and conservation of the tooth substance rather than restoration of the dentition. The presently-used diagnostic methods of detecting early lesions require visual observation. Reflected light is used to detect changes in color, texture, and translucency of the tooth substance. Attempts to improve the traditional methods or to develop new ones have been numerous. For clinical use, only 2 quantitative methods are presently available: (i) a method based on the scattering of light by enamel crystals in relation to their surrounding environment, and (ii) a method that uses visible laser light within the blue-green region as the light source to excite the autofluorescence of enamel. The possibilities and limitations of these methods are evaluated, and clinical applications are presented and discussed.
Mineral loss in incipient caries lesions quantified with laser fluorescence and longitudinal microradiography. A methodologic study.
The laser fluorescence method (LAF) was validated with longitudinal microradiography (LMR) for assessment of mineral loss in incipient caries lesions in human enamel. Fluorescence radiance scans and LMR recordings were made of 36 enamel slabs with incipient lesions. Original sound values for fluorescence radiance and enamel amount (kg.m-2) at the lesion site were reconstructed by a computer algorithm. Changes in fluorescence radiance and amount of enamel in each measuring point were calculated. The reconstruction method was tested on 20 sound enamel surfaces. The differences between measured and reconstructed values were -0.13 +/- 0.17% with LAF and 0.002 +/- 0.005 kg.m-2 with LMR. The repeatability of the caries quantification was tested by measuring one lesion 20 times. The fluorescence loss in this lesion was 18.2 +/- 1.0%. The enamel loss was 0.09 +/- 0.02 kg.m-2. The correlation between measurements with the two methods was r = 0.73. The non-destructive laser fluorescence method was concluded to be a sensitive and valid method for quantification of mineral loss in enamel caries lesions.