To establish the normal dental development pattern of the ICR/Jcl strain of mouse, we analyzed a significant number of observations of the different developmental stages of the first mandibular molar, accurately recording the chronology of their daily embryonic development. Proliferation of the dental sheet began at day 12.5 in utero (E-12.5), the bud stage appeared at days E-13.5 and E-14.5, the cap stage was observed at days E-14.5, E-15.5 and E-16.5 and the early bell stage at day E-17.5. The presence of predentin was observed at day E-18.5 and dentin was observed 1 and 2 days after birth (D-1 and D-2). The late bell stage with presence of enamel was detected more than 3 days after birth. Embryonic and dental development in the ICR/Jcl strain of mouse is faster than in other well-known strains. The establishment of this developmental pattern will be useful for future investigations of transgenic mice. (J. Oral Sci. 46, 135-141, 2004)

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The purpose of this study was to evaluate the filler compositions of recently available light-cured resins. The composition of each resin paste was evaluated using an energy dispersive X-ray fluorescence spectrometer. Scanning electron microscopic observation of the polymerized resin pastes was also conducted. The main component of each resin composite was Si, while the other elements detected were Al, Ba, Sr, Zr, and K. These elementary compositions differed among the resin pastes used. Three different types of filler morphology were observed; splintered, prepolymerized and splintered, and spherical. The results of this study have thus characterized recently developed resin composites based on their filler elements and morphology. (J. Oral Sci. 46, 143-148, 2004)

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It is of great importance to understand the distribution of periodontopathogens within family members when considering the risk of periodontitis in children. The purpose of this study was to investigate the distribution of periodontopathogens among family members. We used the polymerase chain reaction method to test 4, 8, and 7 probands with healthy gingiva, gingivitis, and periodontitis, respectively, and their 60 immediate family members. Plaque samples were collected from all erupted teeth sites using a sterile toothbrush. In 161 of the 165 positive cases, if a child harbored one of the periodontopathogens then at least one of the parents was also positive for the same bacterium. The prevalence of parent-child co-infection was 42.9% for Actinobacillus actinomycetemcomitans, 21.4% for Porphyromonas gingivalis, 29.2% for Treponema denticola, 59.5% for Tannerella forsythensis (Bacteroides forsythus) and 16.7% for Prevotella intermedia. Our results indicate that parents could be an important source of periodontopathogens for the colonization that occurs in their children. (J. Oral Sci. 46, 149-156, 2004)

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Although microbiological studies have identified more than 400 bacterial species in periodontal pockets, only a limited number have been implicated as periodontal pathogens. The purpose of this study was to investigate the incidence of cultivable subgingival periodontopathogenic bacteria in chronic periodontitis. Bacterial samples were collected with sterile paper points from the deepest periodontal pockets ((5 mm) of 203 patients: 92 males and 111 females, aged 35-55 years. The samples were cultured under anaerobic and capnophilic conditions using selective and nonselective media. Isolates were characterized to species level by conventional biochemical tests and a commercial rapid test system. The isolates were Actinobacillus actinomycetemcomitans (26.8%), Porphyromonas gingivalis (21.9%), Capnocytophaga sputigena (16.7%), Eikenella corrodens (13.2%), Prevotella intermedia (10.5%), Prevotella disiens (3.1%), Peptostreptococcus micros (2.9%), Capnocytophaga gingivalis (2.2%), Prevotella corporis (1.8%), Peptostreptococcus magnus (1.3%) and Fusobacterium nucleatum (0.4%). No periodontopathogenic bacterial growth was observed in 14 of the samples (6.2%). The number of samples associated with monobacterial growth and polybacterial growth were 74.9% and 18.2% respectively. It is concluded that the bacterial composition associated with a number of patients' samples is quite complex, and that some of cultivable anaerobic and capnophilic bacteria act as periodontal pathogens in chronic periodontitis. (J. Oral Sci. 46, 157-161, 2004)

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Porphyromonas gingivalis is a major etiologic agent of periodontitis and exhibits hemagglutinating and adherence activities. We previously succeeded in molecular cloning the 200-kDa cell-surface antigenic protein (200-k AP), designated pMD101, that is recognized in sera from periodontitis patients, and identified the 200-k AP as a hemagglutinin A (HagA) derivative. HagA is one of the hemagglutinins known to be a useful vaccine against periodontitis. HagA has four large, contiguous, direct repeats and the repeat unit is believed to contain the hemagglutinin domain. Because production of 200-k AP was low in the Escherichia coli host, it was difficult to obtain large amounts of recombinant protein. In this study, we attempt to subclone the gene encoding the useful antigen from pMD101 in an effort to obtain large quantities. A subclone, designated pMD160, encoding a fusion protein of 80-kDa HagA and maltosebinding protein was successfully constructed, and the novel clone produced relatively large amounts of recombinant protein. DNA nucleotide sequences of the pMD160 insert demonstrated that the 80-kDa protein contained a short hemagglutinin motif and a direct repeat unit region. The recombinant protein was purified to homogeneity and rabbit antiserum was raised. The antibody was capable of inhibiting the hemagglutinating activity of P. gingivalis. These findings suggest that novel 80-kDa HagA derivative proteins can be produced efficiently from E. coli hosts and these may be useful in developing immunotherapy against periodontitis infected by P. gingivalis. (J. Oral Sci. 46, 163-169, 2004)

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Progressive chromosome 21 loss in individuals with trisomy 21 or Down syndrome (DS) is supposedly related to their premature senescence. In addition, the telomere hypothesis of cellular aging involving telomere shortening in normal and accelerated aging in vivo and in vitro is well documented. This study investigated the integrity of two chromosome 21 regions (the 21q telomere and the 21q22.13-q22.2 region) and their relationship with aging by means of fluorescence in situ hybridization (FISH) in lymphocytes and gingival fibroblasts cells. The use of tissues from different germ layers allows detection of mosaicism. Chromosome variations in tissue from the neuroectoderm layer could explain the variable phenotype of DS. This approach is original in the literature. Lymphocyte and gingival fibroblast nuclei from 18 affected individuals aged 5-54 years were analyzed. Although not significant (P=0.06), analysis from 11 tissue-matched individuals as well as the comparison between lymphocytes and fibroblasts from different subjects (P=0.05) suggested that lymphocyte cells are more likely to miss 21q telomere signals. Hence, gingival fibroblasts are probably capable of more efficient cell repair, and the occurrence of mosaicism is more related to cell proliferation than to germ layer origin. Investigation of the 21q22.13-q22.2 region from six tissue-matched individuals and from different DS patients revealed no significant differences between the tissues. (J. Oral Sci. 46, 171-177, 2004)

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Objectives: Dental caries prevention programs using chlorhexidine (CHX) have been proposed, but CHX's effect in reducing levels of mutans streptococci (S. mutans and S. sobrinus) appears to last for only a few months. The aim of this study was to attempt to eradicate mutans streptococci from the oral cavity using intensive professional mechanical tooth cleaning (PMTC) and topical application of CHX in custom-made trays. Methods: Seven adult dentate subjects participated in this study (mean age 53.7 +/− 5.6, age range 46 to 62, mean DMFT, 9.1 +/− 4.2). For each subject, PMTC was carried out eight times within ten days. After each PMTC, 1% CHX was applied twice to the tooth surface using custom-made trays. In addition, as home treatment, subjects were required to carry out tooth brushing three times a day, and apply 0.2% CHX in custom trays after brushing in the morning and evening. In addition, subjects rinsed with 0.2% CHX solution after lunch. Salivary levels of mutans streptococci were evaluated using Dentocult-SM at baseline and on days 9, 20, 70, 120. Results: Mutans streptococci were eradicated by day 120 from 4 of the 7 seven subjects participating in this study. Those 3 subjects still harboring mutans streptococci exhibited deep periodontal pocketing. Conclusions: Eradication of mutans streptococci from the oral cavity is feasible using a combination of CHX application in custom-made trays and intensive PMTC. (J. Oral Sci. 46, 179-183, 2004)

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This study examined the influence of various adhesive systems on dentin bond strength of direct core foundation resins. Two commercially available direct core foundation resin systems and 2 adhesive polymerization modes were used. Facial bovine dentin surfaces were wet ground on 600-grit SiC paper. Dentin surfaces were treated according to the manufacturers' instructions and were light polymerized (control). Chemical- and light-polymerized adhesive systems were used separately. The resin paste was condensed into a mold and bonded to the dentin surface. Ten specimens per test group were stored in water at 37°C for 24 hours, and a shear test was conducted at a crosshead speed of 1.0 mm/minute using a universal testing machine. Analysis of variance (ANOVA) and Duncan's multiple comparison test were performed (α=0.05). Dual polymerization of resin pastes revealed higher bond strength with the combination of light-polymerized adhesive (22.8-24.3 MPa), but significantly lower bond strength with the combination of a chemical-polymerized adhesive (4.2-5.7 MPa). The present data suggests that dentin bond strengths in direct core foundation systems can be influenced by the combination of adhesive and resin paste. (J. Oral Sci. 46, 185-189, 2004)

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The aim of this study was to compare differences in oral health behavior between dental students and dental technology/dental hygiene students in Jordan. One hundred and five dental students and seventy-eight dental technology/dental hygiene students were recruited into this study. All subjects were recruited from the students who were receiving training at the clinics and laboratories that belong to the Faculty of Dentistry, Jordan University of Science and Technology. The Hiroshima University-Dental Behavioral Inventory (HU-DBI) was used to assess the oral heath behavior of the subjects. Significant differences were found between students from different disciplines. Dental students were found to worry more about visiting their dentist, to be less aware of bleeding gums when brushing and were less bothered by the color of their gums compared with dental technology and dental hygiene (DT/DH) students (P < 0.05, P < 0.001 and P < 0.05, respectively). Dental students tended to be more professionally educated about brushing and to have a belief that they cannot clean their teeth well without using toothpaste (P < 0.01 and P < 0.001, respectively). Most of them did not feel they have brushed well unless they brush with strong strokes (P < 0.05). A logistic regression model showed that it might be possible to distinguish dental students from DT/DH students by using three items of the HU-DBI and the level of dental education. The difference in the HU-DBI scores was not a major feature. There were significant differences in oral health attitudes/behavior between dental students and DT/DH students. The findings might reflect differences in students' training experience and education between different specialties. (J. Oral Sci. 46, 191-197, 2004)

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A 50-year-old man was admitted to our clinic with a complaint of lingual enlargement. Detection of non-caseous epithelioid granuloma on histopathological examination led to a diagnosis of a granulomatous glossitis. Extensive investigation for the presence of associated disorders yielded negative results. Metranidazole and clofazimine were totally ineffective and tetracycline led to a minimal improvement. No associated disorder was detected at a 4-year follow-up examination. The position of granulomatous glossitis within the spectrum of orofacial granulomatous conditions is discussed. (J. Oral Sci. 46, 199-202, 2004)

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