Risk behaviors and its association with caries activity and dental caries in Japanese children

The aim of this study was to assess risk behaviors and its association with caries activity and dental caries in Japanese children. The subjects were 392 young Japanese children who underwent dental health check-up at 18, 30 and 42 months of age. Oral examinations, Cariostat tests and dental health questionnaires were carried out at each time. The caries prevalence of children was 1.5% at 18 months, 9.9% at 30 months and 28.1% at 42 months. Caries activity based on the Cariostat scores of children was correlated with caries status (caries-free/carious) at 42 months. In children with caries during each examination period at 42 months, eating snacks while playing was ranked as the most important behavioral risk (P < 0.001), followed by breast-feeding (P < 0.01), non setting of time for snacks (P < 0.05) and frequency of snacks (P < 0.05) at 18 months old; non brushing by mother (P < 0.05) and eating snacks while playing (P < 0.05) were ranked highest at 30 months old. In addition, eating snacks while playing (P < 0.001) at 42 months old was the only a significant factor for children with caries. Caries activity and risk behaviors were associated with caries experience at different age periods of childhood.     

Sex differentials in caries frequencies in Medieval London

ObjectiveTooth decay is one of the most common oral infections observed in skeletal assemblages. Sex differentials in caries frequency are commonly examined, with most studies finding that females tend to have a higher frequency of carious lesions (caries) compared to males. Less research has examined differences in caries between males and females with respect to age in past populations. Findings from living populations indicate that caries frequencies are higher in females, at least in part, because of the effects of estrogen and pregnancy. We are interested in the interaction of age, sex, and caries in medieval London, during a period of repeated famines, which might have exacerbated underlying biological causes of caries sex differentials.DesignWe examined caries in adults from two medieval London cemeteries dating to c. 1120–1539 AD: St. Mary Spital (n = 291) and St. Mary Graces (n = 80) to test the hypothesis that males and females have different caries frequencies irrespective of age. The association between maxillary molar caries and sex was tested using hierarchical log-linear analysis to control for the effects of age on caries frequencies.ResultsThe results indicate a higher frequency of maxillary molar caries in females (P < 0.00), and that the age distribution of caries differs between the sexes (P = 0.01), with a consistent increase in frequency with age for females until late adulthood, but not males.ConclusionsThe difference in caries frequencies is not explained by differences in the age distributions of the sexes. Differences in the age patterns of caries for males and females could be the result of biological factors that present during reproductive age, differences in diet, or differential access to resources during famine.     

The effect of surface defects in early caries assessment using quantitative light-induced fluorescence (QLF) and micro-digital-photography (MDP)

ObjectivesThe purpose of this study was to consider the impact of surface defects on quantitative light-induced fluorescence (QLF) and micro-digital-photography (MDP) measures, in relationship to lesion depth.MethodsSimulated enamel carious lesions were developed on 45 extracted human teeth. Images of each tooth were captured with both QLF and MDP. The teeth were sectioned and lesion depth was measured with polarized light microscopy (PLM). Pearson correlations were computed using data from the 27 lesions which did not have surface loss, and then separately based upon the 18 lesions which did display surface loss. MDP variables ΔR and ΔX measure reflected light, whereas QLF variables ΔF and ΔQ measure fluorescence.ResultsA strong correlation was identified between lesion depth and ΔF (r = ?0.765, p < 0.0001), and ΔQ (r = ?0.827, p < 0.0001) on intact lesions while a weak but suggestive, although non-significant, correlation was identified between average lesion depth and ΔR (r = 0.369, p = 0.059) and ΔX (r = 0.595, p = 0.0011). However, the corresponding correlation was not statistically significant, when lesions with surface loss were considered for QLF and MDP measures.ConclusionsQLF measures ΔF and ΔQ were strongly correlated with lesion depth in lab-simulated lesions with no surface loss, but not among lesions with surface defects. The two MDP-associated measures, ΔR and ΔX, could not be said to differ significantly when lesions with and without surface defects were compared with lesion depth. Because intact lesions can be remineralized, accurate assessment of their status is imperative for caries treatment.Clinical significanceDental caries is still widely prevalent today. We now know that with early stage detection, remineralization can be accomplished. Being able to identify dental caries in its reversible stage (before physical surface loss) is paramount for the clinician to be able to treat the disease non-invasively.     

Prevalence of delayed tooth development and its relation to tooth agenesis in Korean children

ObjectiveThe aim of this study was to investigate the epidemiology of delayed tooth development (DTD) and the link between DTD and tooth agenesis (TA).DesignThe dental maturity of all of the developing permanent teeth of 4611 children (2417 males and 2194 females) was evaluated from panoramic radiographs. The prevalence of DTD and TA was analyzed, and gender difference for DTS and TA was investigated. The correlation of DTD and TA was investigated in intra-fields and inter-fields.ResultsThe total prevalence of DTD among the 4611 children was 3.40%. The maxillary second premolar was the most frequently delayed tooth (1.02%), followed by the maxillary second molar (0.88%) and the mandibular second premolar (0.74%). DTD significantly correlated with TA in both intra-fields and inter-fields (p < 0.05).ConclusionsThe field of delayed development exhibited a significant correlation with that of TA.     

Association study for the role of Matrix metalloproteinases 2 and 3 gene polymorphisms in dental caries susceptibility

ObjectiveVarious exogenous and endogenous risk factors have been described as contributing to dental caries susceptibility. In the last decade it has been established that both pro and active forms of host derived Matrix metalloproteinases (MMPs) are present in the oral cavity. MMPs role in caries development has been hypothesized. The aim of this study was to analyse MMP2 (rs2287074) and MMP3 (rs679620) single nucleotide polymorphisms (SNPs) and their role in caries susceptibility.DesignThe two SNPs were analysed by PCR- restriction fragment length polymorphism (RFLP) in a sample of 102 ethnic Bulgarian volunteers (42 males and 60 females), all students in Sofia Medical University.ResultsStatistical analysis of the MMP2 SNP showed significant differences for the genotype frequencies between the caries free (CF, DMFT = 0) and low caries experience (LCE, DMFT ≤ 5) groups. Analysis for the non-synonymous MMP3 SNP found significant differences between both CF vs caries experience groups (LCE+ high caries experience (HCE, DMFT ≥ 5)) and LCE vs HCE groups. The presence of allele G decreased the risk of HCE about 4 times.ConclusionsMMP2 and MMP3 genes are likely to be involved in caries susceptibility in our population. However, as dental caries is a multifactorial disorder and several genes are likely to have influence on it, it is reasonable to expect that SNPs, even those proven to be functional like rs679620, potentially play a significant, but not major role in the disease outcome.     

Risk behaviors and their association with presence of S.mutans or S.sobrinus and caries activity in 18-month-old Japanese children

The purpose of this study was to investigate risk behaviors associated with the presence of S. mutans or S. sobrinus and caries activity. The subjects were 448 mother-child pairs who underwent dental health examinations between February 2004 and November 2004 when the children were 18 months old. Caries activity was assessed by the Cariostat test. The presence of S. mutans and S. sobrinus was detected using PCR techniques. Questionnaires regarding risk behaviors were completed by the mothers. A statistically significant correlation was found for the detection of S. mutans and/or S. sobrinus in children and mothers (P < 0.01). High-risk mothers were more likely to have high-risk children (P < 0.001). In children in whom bacteria were detected, breast-feeding was ranked as the most important risk factor (P < 0.01), followed by eating snacks while playing (P < 0.01), getting snacks from neighbors (P < 0.05), being cared for by grandparents (P < 0.05) and pre-chewing of children's food by mothers (P < 0.05). In children with high caries risk, breast-feeding and pre-chewing were the most important risk factors (P < 0.01), followed by taking meals at irregular intervals and mothers not attending maternity classes (P < 0.05).     

Effect of arginine on the growth and biofilm formation of oral bacteria

BackgroundAlkali production via arginine deiminase system (ADS) of oral bacteria plays a significant role in oral ecology, pH homeostasis and inhibition of dental caries. ADS activity in dental plaque varies greatly between individuals, which may profoundly affect their susceptibility to caries.ObjectiveTo investigate the effect of arginine on the growth and biofilm formation of oral bacteria.Methods and resultsPolymicrobial dental biofilms derived from saliva were formed in a high-throughput active attachment biofilm model and l-arginine (Arg) was shown to reduce the colony forming units (CFU) counts of such biofilms grown for various periods or biofilms derived from saliva of subjects with different caries status. Arg hardly disturbed bacterial growth of Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis and Streptococcus gordonii in BHI medium, but only inhibited biofilm formation of S. mutans. Scanning electron microscope (SEM) showed S. mutans biofilms harboured fewer cells grown with Arg than that without Arg, even in the initial 2 h and 8 h phase. Confocal laser scanning microscope (CLSM) images of poly-microbial dental and S. mutans biofilms revealed the biofilms grown with Arg had lower exopolysaccharide (EPS)/bacteria ratios than those without Arg (P = 0.004, 0.002, respectively). Arg could significantly reduce the production of water-insoluble EPS in S. mutans biofilms (P < 0.001); however, quantitative real-time PCR (qRT-PCR) did not show significantly influence in gene expression of gtfB, gtfC or gtfD (P = 0.32, 0.06, 0.44 respectively).ConclusionsArg could reduce the biomass of poly-microbial dental biofilms and S. mutans biofilms, which may be due to the impact of Arg on water-insoluble EPS. Considering the contribution to pH homeostasis in dental biofilms, Arg may serve as an important agent keeping oral biofilms healthy thus prevent dental caries.     

Identification of chromosomal region(s) influencing initial dental caries susceptibility in mice

Predicting the host genetic factors influencing dental caries susceptibility is important to developing preventive strategies in individuals. In this study, Quantitative Trait Locus (QTL) analysis was used to identify the candidate regions for gene(s) influencing initial dental caries susceptibility in mice, and that performed on genetic crosses of BALB/cJ and C3H/HeJ mice. Two significant QTLs on chromosomes 7 and 11 and five suggestive QTLs on chromosomes 3, 8, 16 and 17 were detected. Around the region 50 cM on Chromosome 7 and 46 cM on chromosome 11, the likelihood ratio statistic (LRS) scores showed higher than significant levels. Around 52.5 cM on chromosome 3, 38.4 cM on chromosome 8, 38.0 cM on chromosome 16, and 6.5 cM and 44.5 cM on chromosome 17, LRS scores showed higher than suggestive levels. Based on these results, it is suggested that the candidate gene(s) responsible for dental caries are located in the specified regions of six chromosomes, chromosomes 7 and 11 in particular are associated with initial dental caries.     

Dental primer and adhesive containing a new antibacterial quaternary ammonium monomer dimethylaminododecyl methacrylate

ObjectivesThe main reason for restoration failure is secondary caries caused by biofilm acids. Replacing the failed restorations accounts for 50–70% of all operative work. The objectives of this study were to incorporate a new quaternary ammonium monomer (dimethylaminododecyl methacrylate, DMADDM) and nanoparticles of silver (NAg) into a primer and an adhesive, and to investigate their effects on antibacterial and dentin bonding properties.MethodsScotchbond Multi-Purpose (SBMP) served as control. DMADDM was synthesized and incorporated with NAg into primer/adhesive. A dental plaque microcosm biofilm model with human saliva was used to investigate metabolic activity, colony-forming units (CFU), and lactic acid. Dentin shear bond strengths were measured.ResultsMinimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the new DMADDM were orders of magnitude lower than those of a previous quaternary ammonium dimethacrylate (QADM). Uncured primer with DMADDM had much larger inhibition zones than QADM (p < 0.05). Cured primer/adhesive with DMADDM-NAg greatly reduced biofilm metabolic activity (p < 0.05). Combining DMADDM with NAg in primer/adhesive resulted in less CFU than DMADDM alone (p < 0.05). Lactic acid production by biofilms was reduced by 20-fold via DMADDM-NAg, compared to control. Incorporation of DMADDM and NAg into primer/adhesive did not adversely affect dentin bond strength.ConclusionsA new antibacterial monomer DMADDM was synthesized and incorporated into primer/adhesive for the first time. The bonding agents are promising to combat residual bacteria in tooth cavity and invading bacteria at tooth-restoration margins to inhibit caries. DMADDM and NAg are promising for use into a wide range of dental adhesive systems and restoratives.     

Increased risk for premolar tooth loss in shortened dental arches

ObjectivesTo assess sustainability of shortened dental arches (SDA) by determining time to ‘first restorative intervention’ of teeth and time to ‘tooth loss’ and comparing these outcomes with complete dental arches (CDA) and SDA plus removable dental prostheses (RDP).MethodsData (follow-up time ranged from 27.4 (SD 7.1) to 35.0 (SD 5.6) years; max. follow up: 45.8 years) from patient records of 59 subjects (23 SDA, 23 CDA, and 13 SDA plus RDP) participating in a prospective cohort study on shortened dental arches (SDA) were analysed. Group effects on survival were analysed using Cox regression models; where appropriate Kaplan–Meier analyses were done.ResultsCompared to SDA subjects, CDA subjects had a lower risk to receive a first restorative intervention in anterior teeth (HR = 0.377; 95% CI [0.205–0.695]) and premolars (HR = 0.470; 95% CI [0.226–0.977]). CDA subjects had a lower risk to lose premolars compared to SDA subjects (HR = 0.130; 95% CI [0.053–0.319]). Risk for ‘first restorative intervention’ and for ‘tooth loss’ did not significantly differ between SDA with and without RDP.ConclusionsSDA subjects had an increased risk to lose premolars and to receive a first time restoration in anterior teeth and premolars compared to CDA subjects. SDA subjects with RDP had no increased risk to receive a first restorative intervention or for tooth loss compared to SDA without RDP.Clinical relevanceSubjects with shortened dental arches can be discerned as enduring at-risk patients. It is therefore recommended that shortened dental arch subjects receive intensive and continuous care to prevent further tooth loss.     

A randomized controlled trial by the 3DS for dental caries

The aim of this study is to evaluate the povidone-iodine for the suppression of oral cariogenic bacteria and compare its effects to that of fluoride in children. We carried out a randomized controlled trial to compare the effects of povidone-iodine to those for sodium fluoride. Pre-school children (n = 210) with more than 10⁵ cfu/ml mutans streptococci in their stimulated saliva were randomly sampled and randomly allocated into three groups. We planned the preventive program by 3DS (Dental Drag Delivery System). The groups that provided preventive programs were the povidone-iodine group (n = 70) and the sodium fluoride group (n = 70). A control group (n = 70) received no intervention. Povidone-iodine or sodium fluoride was applied to the tooth surface using custom made trays. Subsequent home care was obligatory for one month. After one month, the salivary levels of mutans streptococci were low level when compared to the based data. However the difference in salivary levels of mutans streptococci among groups was not statistically significant when comparing the povidone-iodine group with the sodium fluoride group (P = 0.625). After 2.5 years follow up, differences in incidence of new dental caries among the three groups were not statistically significant (P = 0.583). Clinical application of anti-microbial drugs may be effective, but only a single intervention is not sufficient to reduce the incidence of new dental caries.     

The association of Enamelin,Lactoferrin, and Tumour necrosis factor alpha gene polymorphisms with high caries susceptibility in Chinese children under 4 years old

ObjectiveThe aim of this study was to assess the role of ENAM rs3796703, LTF rs1126478, and TNF-α rs1800629 in high caries susceptibility.DesignThe present case–control study included 1005 unrelated children under 4 years old: 505 with severe caries (dmft index ≥4) and 500 who were caries-free (dmft index = 0 and without white-spot lesions). Questionnaires were obtained from parents and gardians about the children’s diet and oral behavioural habits. All the children received dental examinations and oral swabbing for human genomic DNA collection. ENAM rs3796703, LTF rs1126478, and TNF-α rs1800629 were genotyped by Sanger sequencing.ResultsThe frequency of the ENAM rs3796703 T allele (6.7% in the caries group and 4.2% in the caries-free group), CT genotype (12.7% in the caries group and 8.4% in the caries-free group), TNF-α rs1800629 A allele (4.8% in the caries group and 6.8% in the caries-free group), and AG genotype (8.7% in the caries group and 13.2% in the caries-free group) were significantly different between the caries and caries-free groups (p < 0.05). No significant difference was found in the LTF rs1126478 allele frequency and genotype distribution between the two groups. The ENAM rs3796703 CT genotype increased caries susceptibility by 60.9% compared to the CC genotype (β = 0.746, OR = 1.609), and the TNF-α rs1800629 AG genotype reduced caries susceptibility by 47.4% compared to the GG genotype (β = −0.642, OR = 0.526). In terms of habits covariates, prolongation of night feeding time by 1 month increased caries susceptibility by 3.3% (β = 0.033, OR = 1.033); additionally, sweets and acidic drinks consumption 1–2 times per day increased caries susceptibility by 218.2% (β = 1.158, OR = 3.182), and consumption 3 or more times pe/r day increased susceptibility by 883.5% (β = 2.286, OR = 9.835) compared to non-consumption. Topical fluoride application decreased caries susceptibility by 43.0% (β = −0.562, OR = 0.570).ConclusionsThe ENAM and TNF-α genes are likely associated with caries experience in Chinese children. The ENAM rs3796703 CT genotype might be involved in caries susceptibility, while TNF-α rs1800629 AG genotype might be involved in caries protection.     

Detection of mutans streptococci in plaque samples from Mongolian preschool and school children

Mutans streptococci, in particular Streptococcus mutans and Streptococcus sobrinus, are generally considered to be the principal microbial pathogen of dental caries. The objective of the study was to isolate S. mutans and S. sobrinus, identify them by PCR, and to compare their presence with the caries status and caries risk in Mongolian preschool and school children. Forty one preschool children aged 3–5 years and 40 school children aged 12–15 years were enrolled in this study. As assessed using Cariostat test, 75.6% of preschool children had high caries risk and 37.5% of school children had high caries risk. In preschool children, the prevalence of S. mutans and S. sobrinus were 100% and 36.6%, respectively; 63.4% were positive for S. mutans alone and 36.6% were positive for both S. mutans and S. sobrinus. In school children, the prevalence of S. mutans and S. sobrinus were 100% and 25.0%, respectively; 75.0% carried S. mutans alone and 25.0% had both S. mutans and S. sobrinus. The percentage of children positive for both S. mutans and S. sobrinus in the high caries risk group were significantly higher than those in the low risk group of either preschool (42.0% vs. 10.0%, P< 0.001) or school children (46.6% vs. 12.0%, P<0.001). Moreover, the caries status of children positive for both S. mutans and S. sobrinus were significantly higher than those positive for S. mutans alone (P< 0.01 for preschool children, and P< 0.05 for school children).     

Prevalence of apical periodontitis and quality of root canal treatment in an adult Palestinian sub-population

PurposeThe aim of this study was to determine the prevalence of apical periodontitis and the technical quality of root canal fillings in a Palestinian sub-population.MethodsThe panoramic radiographs of 258 patients (142 females, 116 males) attending dental clinics in 2010 were examined to identify the presence of apical lesions associated with any remaining teeth, excluding third molars. The technical quality of root canal fillings was also evaluated by assessing apical extension from the radiographic apex. The panoramic radiographs were taken by a well-trained radiology assistant and evaluated by a radiologist and an endodontist. Statistical analysis was performed with the chi-square test with a significant level set at P < 0.05%.ResultsOf 6482 teeth examined radiographically, 978 (15.1%) had radiographic signs of apical periodontitis (AP). The prevalence of AP was 8.3% in teeth without filled roots and 59.5% (509/855) in root canal-treated teeth. The prevalence of AP and endodontic treatment increased with age and differed significantly (p < 0.05) between males and females. The majority (74.5%) of root canal fillings was performed inadequately, and most (77.2%) inadequate fillings were >2 mm short of the radiographic apex. The presence of AP was correlated significantly with poorly executed root canal fillings (p < 0.05).ConclusionsThe present study found a high prevalence and incidence of AP in association with root-filled teeth. The technical quality of many root canal treatments was unacceptable.     

Presence of Streptococcus mutans or Streptococcus sobrinus in Cariostat®-inoculated plaque samples from Japanese mother-child pairs

The aim of this study was to determine the presence of Streptococcus mutans or Streptococcus sobrinus in Cariostat-inoculated plaque samples obtained from Japanese mother-child pairs through a conventional PCR technique and to establish the presence of these bacteria and caries risk. Oral examination and caries risk assessment using the Cariostat^® were carried out on 168 children, aged 6–31 months, and their mothers. The presence of S. mutans and S. sobrinus in Cariostat-inoculated plaque samples was checked through PCR and tested for relevance with caries risk. A significant correlation (P < 0.001) was found between caries risk of mothers and presence of S. mutans or S. sobrinus in plaque samples from their children in the 19–31-month-old age range. However, no significant relationship found between the presence of either strain in the plaque of younger children (6–18 months) and caries risk of mothers. Likewise, high caries risk was seen in 49.1% of the 19–31-month-old children of highrisk mothers (P < 0.001) and 27% of the 6–18-month-old children of high-risk mothers (P < 0.05). The effectiveness of the Cariostat method for prediction of caries risk can be improved by detecting the presence of S. mutans and S. sobrinus in plaque samples obtained from mothers and their children through conventional PCR techniques.     

A Study of dental caries prevalence in 12–14 year old school children in Ibadan,Nigeria

The aim of the study was to determine dental caries prevalence among a representative sample of 12–14 year old school children in Ibadan, Nigeria with a view of determining Restorative Index and Met Need Index of the studied population. Dental caries was diagnosed according to the WHO method. Out of the 577 children in the age group, 65 children (11.2%) had dental caries experience as expressed with the DMFT index. More than 85% of the children were caries free. A mode of one DMFT was the highest score for the children although a 14-year-old pupil had DMFT score of 6. Female children had higher mean DMFT score of 2.03 ± 1.13 compared with 1.78 ± 1.0 for males (P > 0.05). The Restorative Index (RI) and Met Need Index (MNI) for the children were very low as only the 14-year-old children had an RI of 3.45% and MNI of 0.11. Restorative Index reflects the restorative care of those who have suffered the disease and it is measured as a ratio of filled to filled plus decayed teeth percent that is F/F+D percent. Met Need Index is an indication of treatment received by an individual and it is measured by the ratio of the mean missing plus filled teeth to mean decayed, missing and filled teeth that is M+F/DMF. Since cost of management, which may be out of the reach of these children, has been identified as one of the factors militating against their receiving treatment, the result of this study suggest that oral health education with emphasis on correcting snacking habits of school children is desirable.     

In vivo comparison between measurement from two fluorescence-based devices of occlusal and smooth surface caries in primary and permanent teeth

Fluorescence-based devices are adjunct tools for caries detection. Both DIAGNOdent 2095 (LF) and DIAGNOdent 2190 (LF pen) were developed for this application. The purpose of this in vivo study was to compare the relationship between the measurements obtained using the LF and LF pen devices in primary and permanent teeth. The same sample of occlusal and smooth surfaces caries were evaluated by one examiner using both LF and LF pen devices in children. For occlusal caries, measurements were made at 51 sites in primary teeth, and at 83 sites in permanent teeth. For smooth surface caries, measurements were made at 63 sites in primary teeth, and 163 sites in permanent teeth. The values obtained with the LF pen for occlusal caries in primary and permanent teeth (17.6 ± 2.14, 20.6 ± 1.40, respectively) were significantly higher than those obtained with the LF (9.7 ± 1.24, 11.3 ± 0.78). For caries on smooth surfaces, the values obtained with the LF pen for primary and permanent teeth (8.2 ± 1.22, 7.2 ± 0.45) were higher than those obtained with the LF (4.5 ± 0.57, 3.3 ± 0.23). For both occlusal and smooth surface caries, the values were significantly different between the two devices (P < 0.01). The Spearman's correlation coefficients comparing the LF and LF pen values for primary and permanent teeth were Rs = 0.87 and 0.86 for occlusal caries and 0.80 and 0.74 for smooth surface caries, respectively. Values from both devices showed high correlation coefficients, indicating similar principle of function. However, the actual values were significantly different, which indicated that the values obtained with the two devices did not agree. The LF pen should be used with caution in patients for whom the LF is already being used to manage caries.     

Evaluation of factors related to nursing caries in 18-month-old Japanese children

Dental caries in early childhood is a significant public health problem, among which nursing caries is known to be caused by inappropriate nursing habits. The aim of the present study was to investigate lifestyle factors related to nursing caries. We examined 2,506 Japanese children aged 18 months, as a part of public health examinations conducted by the Municipal Public Health Center in 2008. Questionnaires were also administered to their guardians, which focused on nutritional and dental health conditions. Statistical analyses were then performed to determine significant nutritional and dental health factors associated with nursing caries. There were 117 children (4.7% of total) identified with dental caries, of whom 18 (0.7% of total cohort, 15.3% of children with dental caries) were designated as the nursing caries group. Statistical analyses revealed that breastfeeding was the most important factor as compared to children without nursing caries (P = 0.0002; odds ratio, 6.373). Our results showed that inappropriate breastfeeding is one of the most important factors related to both onset and exacerbation of nursing caries, and conclude that parents should be informed of appropriate breastfeeding practices by dentists for their prevention.     

Quantitative assessment of salivary oral bacteria according to the severity of dental caries in childhood

This study aimed to assess differences in selected oral bacteria in children according to the severity of dental caries. One hundred and thirty-six children, 36–60 months old were divided into three groups according to caries status: caries-free (CF) (n = 47), early childhood caries (ECC) (n = 40) and severe-early childhood caries (S-ECC) (n = 49). Saliva was collected for detection and quantification of selected oral streptococci, Actinomyces naeslundii, Lactobacillus spp., Bifidobacterium spp., and Scardovia wiggsiae by quantitative-polymerase chain reaction. The results showed that the detection and quantitative levels of S. mutans, S. sobrinus, Bifidobacterium spp. and S. wiggsiae were significantly higher in S-ECC children compared to CF and ECC children, while for S. salivarius were significantly higher in CF compared to ECC and S-ECC children. There was no statistical difference among the clinical groups for S. mitis, S. oralis, A. naeslundii and Lactobacillus spp. levels and detection. S-ECC children had a lower monthly family income, started tooth brushing later and were breastfeed for a longer duration compared to CF children. S. mutans levels were positively correlated with S. wiggsiae and Bifidobacterium spp. levels, lower mother’s education and child bottle-feeding before sleeping and negatively correlated with S. salivarius. It was concluded that in addition to S. mutans, other bacterial species, including bifidobacteria, Scardovia wiggsiae and S. sobrinus, are associated with severity of early childhood caries, although their role in the progress of dental caries remains unclear.     

Smoking among dental students at King Saud University: Consumption patterns and risk factors

ObjectiveTo assess smoking prevalence among dental students at King Saud University (KSU) and to determine possible risk factors of tobacco use.MethodsA self-addressed invitation letter was sent to all dental students (males and females) at KSU requesting participation in this study. Data on smoking habits, associated risk factors, and demographic factors, such as age, marital status, residency status, the student’s year of study, and grade point average, were collected by an electronic self-administered questionnaire sent via email. Data were analyzed using SPSS. Significant differences between different groups were assessed with a Pearson Chi-Square test at α = 0.05. Logistic regression analysis was used to calculate the odds ratio (OR) and 95% confidence interval (95% CI) and to determine the effect of different risk factors on students’ smoking habits.ResultsOf the 600 registered dental students, 400 students responded (230 males, 170 females), representing a response rate of 67%. More male than female students were current smokers (27.6% vs. 2.4%, p < 0.001). Most smokers used shisha tobacco only (N = 35, 51.5%), followed by both shisha tobacco and cigarettes (N = 17, 25%), or cigarettes only (N = 16, 23.5%). Male students were about 4 times more likely to be smokers if all or most of their friends were smokers compared to students who had some friends who smoked (OR = 3.9, 95% CI = 1.9–7.7). A high proportion of current smokers (47.8%) reported stress as the main reason for smoking. Twenty-six percent of dental students (N = 87) who are currently nonsmokers reported that they have used tobacco at some point in their lives. Over two thirds of sampled students (63%) believed that public tobacco usage is not well addressed in the current college curriculum.ConclusionApproximately one in every four male dental students at KSU is a smoker. Having friends who are smokers was the most important risk factor associated with smoking. There is a general belief among dental students that public tobacco use is not well addressed in the dental college curriculum.