Dental plaque microbiota profiles of children with caries-free and caries-active dentition.

OBJECTIVE: Microbiota comparisons between healthy and diseased dental tissues have accentuated the importance of cultivating and identifying bacterial species that play a role in the initiation and progression of dental caries. The objective of this study was to evaluate the bacterial community composition in caries-active and caries-free children. METHODS: Supragingival plaque samples were collected from 64 caries-active and 64 caries-free Middle Eastern children. The hypervariable V3-V4 of the bacterial 16S rRNA gene was sequenced with Human Oral Microbe Identification using Next Generation Sequencing. Microbial community structure and composition analyses were performed by processing operational taxonomic units. Bioinformatic analyses, including analysis of similarity, alpha and beta diversities, and principal coordinate analysis, were carried out. RESULTS: Diversity indices did not find differences between the caries-active and caries-free groups (p > 0.05). Similarity analysis demonstrated that the microbiota composition did not differ between the two groups. Comparative analysis at the species level revealed a significantly higher relative abundance of Leptotrichia shahii, Prevotella melaninogenica, Veillonella dispar, Leptotrichia HOT 498, and Streptococcus mutans in caries-active children (p < 0.05). Corynebacterium matruchotii, Lautropia mirabilis, Neisseria elongata, and Corynebacterium durum were relatively more abundant in the caries-free group (p < 0.05). Species belonging to the Leptotrichia, Prevotella, and Veillonella genera were significantly predominant in the caries-active subjects. CONCLUSION: In view of the lack of a clear association between Corynebacterium spp. and dental caries status in the literature, the predominance of these species in caries-free children warrants further research to understand their possible role in a health-associated microbial community. CLINICAL SIGNIFICANCE: Understanding the relationship between specific bacteria present in dental biofilms and health and disease is essential for preventing and combating dental caries. Using advanced next generation sequencing techniques, the present study demonstrated the complexity of the caries microbiome and identified species/genera whose virulence or protective properties should be further explored.

The periodontal disease-systemic health-infectious disease axis in developing countries.

Oral health is relatively low priority in the health policy of many developing countries. These countries, particularly those in sub-Saharan Africa, are still constrained by a wide range of infectious diseases such as HIV/AIDS, tuberculosis, measles and malaria, as well as by a heavy burden of intergenerational malnutrition. There is currently a disturbing trend in the rise of noncommunicable diseases in these countries. The noncommunicable diseases share many risk factors with periodontal diseases, the prevalence and severity of which are already markedly influenced by microbial infections. There are many fundamental gaps in our understanding of oral diseases, particularly in resource-poor settings. Perhaps this is the time to integrate neglected oral diseases and the noncommunicable diseases into the relatively well-funded global programs for the elimination of malaria, tuberculosis, AIDS and malnutrition.

Comparison of the use of the Halimeter and the Oral Chroma™ in the assessment of the ability of common cultivable oral anaerobic bacteria to produce malodorous volatile sulfur compounds from cysteine and methionine.

OBJECTIVE: To compare the use of the Halimeter and the Oral Chroma™ to assess the ability of common oral anaerobic bacteria isolated from the Kuwaiti population to produce volatile sulfur compounds (VSCs). MATERIALS AND METHODS: Broth cultures of common anaerobes isolated from supragingival plaque were centrifuged and pellets resuspended in phosphate buffer (pH 7.7) with an optical density OD(550) of 0.3. 100 µl of this suspension and 870 µl of buffer were added in 2 sterile 15-ml head space vials. Reaction was initiated by addition of 30 µl of 33 mML-methionine and L-cysteine, respectively, in each vial and incubation at 37°C for 90 min. 500 µl of 3 M phosphoric acid was added to tubes and was kept aside for 10 min. Production of VSCs was measured using the Halimeter and the Oral Chroma. RESULTS: The major VSC producers identified by both Halimeter and Oral Chroma with L-cystenine as substrate were Campylobacter ureolyticus, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Aggregatibacter actinomycetemcomitans and Gemella morbillorum. The concentrations of hydrogen sulfide recorded by both Halimeter and Oral Chroma were essentially identical. With L-methionine as substrate, both Halimeter and Oral Chroma identified different complements of anaerobes with C. ureolyticus,P. gingivalis,Fusobacterium nucleatum and P. intermedia as major VSC producers. The concentrations of methyl mercaptan recorded by the Halimeter were lower compared to those assessed by the Oral Chroma. CONCLUSION: The results suggest that the Oral Chroma may produce a more comprehensive assessment of VSC production by oral microflora than the Halimeter.

Prevalence of periodontal bacteria in saliva of Kuwaiti children at different age groups.

Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, Tannerella forsythensis and Porphyromonas gingivalis and to a lesser extent Prevotella intermedia and Prevotella nigrescens, are Gram-negative species that are associated with destructive periodontitis. Studies from different parts of the world have shown variable detection rates of periodontal organisms. Hardly any data exist on their carriage in children living in the Middle East. This study was designed to determine the detection of these species in the oral cavity of 240 generally healthy Kuwaiti children, divided into five age groups: <6 years (n=40), 6-9 years (n=60), 10-12 years (n=40), 13-15 years (n=40) and 16-18 years (n=60). Saliva was used as the microbiological specimen, and the samples were analyzed by molecular methods using multiplex PCR. A total of 185 (77.1%) of the 240 children were colonized by at least one of the target periodontal bacteria. In all age groups, P. nigrescens was the most prominent and detected in saliva of 15%, 32%, 63%, 50%, and 47% of the children at the five age groups, respectively. P. gingivalis was detected only occasionally. Only few pathogens were found before the permanent dentition, i.e. at the age of <6 years. The highest carriage rates were from the groups between 6 and 15 years of age. The salivary carriage of the pathogens was essentially similar in the age groups of 10-12 years and 13-15 years. In conclusion, except for P. gingivalis, the examined periodontal pathogens are relatively common findings in Kuwaiti children and colonize the oral cavity from childhood onwards.

The prevalence and antibiotic sensitivity of oral Viridans streptococci in healthy children and children with disabilities in Kuwait.

The purpose of this study was to compare the antibiotic susceptibility profiles of Viridans streptococci (VS) isolated from the oral cavity of healthy children and children with disabilities in Kuwait. Plaque samples were collected from the tooth and tongue surfaces of 102 healthy children and 102 children who were intellectually disabled and institutionalized. The resistance to seven antibiotics (amoxicillin, cephalothin, clindamycin, erythromycin, penicillin G, tetracycline, and vancomycin) was tested. A total of 330 (44.5%) VS were isolated from the children who were healthy and 411 (55.5%) from children with disabilities. The most common isolates were S. salivarius (27.3%) in healthy children; S. sanguis (22.6%) was predominant among children who were disabled. S. mutans was found in 12.1% of the healthy children and in 16.5% of the children who were disabled. The combined percentage of resistant strains (healthy and disabled) was found to be highest with amoxicillin (43%) and lowest with vancomycin (12%). S. sanguis, S. mitis and S. oralis were more resistant in healthy children (45%, 56%, and 55% respectively) than in children with disabilities (40%, 47% and 47% respectively). S. mutans was the least resistant species to all antibiotics in both groups of children. About 56% of all streptococci isolated from both groups were resistant to at least one of the antibiotics tested. The data showed that there was a difference in the level of resistance of oral VS isolated from healthy children and children with disabilities to some antibiotics commonly used in dentistry.

Factors associated with self-reported halitosis in Kuwaiti patients.

OBJECTIVES: Oral malodor is a common complaint of dental patients, yet limited data is available on the actual prevalence of this condition. The aim of this study was to assess the prevalence and factors associated with self-reported halitosis in Kuwaiti patients. METHODS: This was a cross-sectional study of Kuwaiti adults using a 19-point self-administered structured questionnaire on self-perception of halitosis. Significant associations between self-reported oral malodor and sociodemographic, medical history, and oral hygiene variables were examined with multiple logistic regression analysis. RESULTS: A total of 1551 subjects participated (response rate=86.2%). The prevalence of self-reported halitosis was 23.3%. Use of the toothbrush less than once daily was the factor most strongly associated with self-perceived halitosis (OR=2.68; 95% CI=1.83-3.92; p<0.001). Other factors significantly associated with self-perceived halitosis included current or past smoking (OR=2.51), female gender (OR=1.54), being 30 years of age or older (OR=1.35), having high school education or less (OR=1.41), history of chronic sinusitis (OR=1.58) or gastrointestinal disorders (OR=1.73), never using miswak (OR=1.56), and never using dental floss (OR=1.33). CONCLUSION: Inadequate oral hygiene practices were the factors most strongly associated with self-reported oral malodor in this sample of Kuwaiti patients. Other factors with significant associations included history of gastrointestinal tract disorders, chronic sinusitis, older age, female gender, and lower education levels.

Comparison of bioactive glass, mineral trioxide aggregate, ferric sulfate, and formocresol as pulpotomy agents in rat molar.

Bioactive glass (BAG) is often used as a filler material for repair of dental bone defects. Although there is evidence of osteogenic potential of this material, it is not clear yet whether the material exhibits potential for dentinogenesis. Hence, the aim of the present study was to evaluate BAG as a pulpotomy agent and to compare it with three commercially available pulpotomy agents such as formocresol (FC), ferric sulfate (FS), and mineral trioxide aggregate (MTA). Pulpotomies were performed in 80 maxillary first molars of Sprague Dawley rats, and pulp stumps were covered with BAG, FC, FS, and MTA. Histologic analysis was performed at 2 weeks and then at 4 weeks after treatment. Experimental samples were compared with contra-lateral normal maxillary first molars. At 2 weeks, BAG showed inflammatory changes in the pulp. After 4 weeks, some samples showed normal pulp histology, with evidence of vasodilation. At 2 weeks, MTA samples showed some acute inflammatory cells around the material with evidence of macrophages in the radicular pulp. Dentine bridge formation with normal pulp histology was a consistent finding at 2 and 4 weeks with MTA. Ferric sulfate showed moderate inflammation of pulp with widespread necrosis in coronal pulp at 2 and 4 weeks. Formocresol showed zones of atrophy, inflammation, and fibrosis. Fibrosis was more extensive at 4 weeks with evidence of calcification in certain samples. Among the materials tested, MTA performed ideally as a pulpotomy agent causing dentine bridge formation while simultaneously maintaining normal pulpal histology. It appeared that BAG induced an inflammatory response at 2 weeks with resolution of inflammation at 4 weeks.

Oral findings in Alagille syndrome. A case report.

OBJECTIVE: To highlight the role of dental practitioners in the management of children with liver diseases. CLINICAL PRESENTATION: A 13-year-old girl with Alagille syndrome presented with oral manifestation of end-stage liver disease that needed liver transplant. The dentition showed hypoplastic lesions and severe discoloration. The gingiva was inflamed and edematous due to poor oral hygiene and possibly to the medication the child was placed on to reduce graft rejection. CONCLUSION: Dental considerations should be incorporated in the overall management of children with liver disease and transplant. Consultation with a dental practitioner should be sought before, during and after treatment of such cases.