Comparison of the salivary and dentinal microbiome of children with severe-early childhood caries to the salivary microbiome of caries-free children.

BACKGROUND: The main objectives of this study were to describe and compare the microbiota of 1) deep dentinal lesions of deciduous teeth of children affected with severe early childhood caries (S-ECC) and 2) the unstimulated saliva of these children and 3) the unstimulated saliva of caries-free children, and to compare microbiota compositional differences and diversity of taxa in these sampled sites. METHODS: Children with S-ECC and without S-ECC were recruited. The saliva of all children with and without S-ECC was sampled along with the deep dentinal microbiota from children affected by S-ECC. The salivary microbiota of children affected by S-ECC (n = 68) was compared to that of caries-free children (n = 70), by Illumina MiSeq sequencing of 16S rRNA amplicons. Finally, the caries microbiota of deep dentinal lesions of those children with S-ECC was investigated. RESULTS: Using two beta diversity metrics (Bray Curtis dissimilarity and UniFrac distance), the caries microbiota was found to be distinct from that of either of the saliva groups (caries-free & caries-active) when bacterial abundance was taken into account. However, when the comparison was made by measuring only presence and absence of bacterial taxa, all three microbiota types separated. While the alpha diversity of the caries microbiota was lowest, the diversity difference between the caries samples and saliva samples was statistically significant (p < 0.001). The major phyla of the caries active dentinal microbiota were Firmicutes (median abundance value 33.5%) and Bacteroidetes (23.2%), with Neisseria (10.3%) being the most abundant genus, followed by Prevotella (10%). The caries-active salivary microbiota was dominated by Proteobacteria (median abundance value 38.2%) and Bacteroidetes (27.8%) with the most abundant genus being Neisseria (16.3%), followed by Porphyromonas (9.5%). Caries microbiota samples were characterized by high relative abundance of Streptococcus mutans, Prevotella spp., Bifidobacterium and Scardovia spp. CONCLUSIONS: Distinct differences between the caries microbiota and saliva microbiota were identified, with separation of both salivary groups (caries-active and caries-free) whereby rare taxa were highlighted. While the caries microbiota was less diverse than the salivary microbiota, the presence of these rare taxa could be the difference between health and disease in these children.

The microbiota of the mother at birth and its influence on the emerging infant oral microbiota from birth to 1 year of age: a cohort study.

Background: The acquisition of microbial communities and the influence of delivery mode on the oral microbiota of the newborn infant remains poorly characterised. Methods: A cohort of pregnant women were enrolled in the study (n = 84). All infants were born full term, by Spontaneous vaginal delivery (SVD) or by Caesarean section (CS). At delivery a saliva sample along with a vaginal/skin sample from the mother. Saliva samples were the taken from the infant within one week of birth, and at week 4, week 8, 6 months and 1 year of age. We used high-throughput sequencing of V4-V5 region 16S rRNA amplicons to compare the microbiota of all samples. Results: The vaginal microbiota had a lower alpha diversity than the skin microbiota of the mother, while the infant oral microbiota diversity remained relatively stable from birth to 8 weeks of age. The oral microbiota of the neonate differed by birth modality up to 1 week of age (p < 0.05), but birth modality did not have any influence on the infant oral microbiota beyond this age. Conclusions: We conclude thatbirth mode does not have an effect on the infant oral microbiota beyond 4 weeks of age, and the oral microbiota of infants continues to develop until 1 year of age.

A retrospective investigation of the oral health records of a cohort of preschool children who received extractions under general anaesthesia including cost analysis of treatment.

Internationally, a considerable proportion of children aged five years and younger require extraction of teeth due to dental caries and frequently dental general anaesthesia (DGA) is the treatment of choice. AIMS: To investigate the records of a cohort of preschool children (aged five years and younger) referred to the public dental service provided at Cork University Hospital (CUH), Cork, Ireland, for extractions under DGA between the years 2000 and 2002. To determine the characteristics of the sample: disadvantage; the presence of a significant medical history; and, fluoride status. To establish the pattern of appointments and care, before, during and after DGA, and the pattern of dental treatment required up to sixth class (aged 11 to 12 years). METHODS: A retrospective review of dental records of a cohort of preschool-aged children referred for DGA in CUH during the years 2000-2002 was completed. Demographic and clinical data were collated and analysed using Statistical Packages for Social Sciences (SPSS). Costs were provided by CUH and the Health Service Executive (HSE). Data on costs relating to preventive programmes were obtained from information presented in the Irish Oral Health Services Guideline Initiative 2009. RESULTS: A total of 347 children were included with a median age of.fQur years and a range of one to five years. Children with a disadvantage were more likely to require extractions under DGA than their- counterparts (50%, n=175). In total, 73% (n=253)~ of patients had a fluoridated water supply and 91% (n=316) had no adverse medical history. For 88% (n=306), their first dental visit was an emergency appointment. The primary indication for DGA was treatment of dental caries. A recall appointment was provided for 18% (n=63). One-quarter (n=86) required an extraction, antibiotic or referral for a second DGA at their first visit following DGA. In first class, referral for a second DGA or extraction under local anaesthetic (LA) was required for 23% (n=79) of patients. Over 60% (n=21 1) required either an extraction or a restoration in third class. In excess of 20% (n=69) of patients did not attend the sixth class dental inspection, the final assessment appointment in the public services. CONCLUSIONS: A considerable number of preschool children require extractions under DGA due to dental caries. The results of this study indicate that such children progress to adolescence with poor oral health, as evidenced by the need for further restorations, extractions and repeat DGA. The average cost of DGA was E819 per child. This figure has been shown to be as much as eight times the cost of a preventive/oral health promotion prograrnme operating within a similar cohort. An integrated preventive programme targeting preschool-aged children should be considered in attempting to manage the hicih levels of dental caries within this age group.

Dentists' requirements for continuing professional development in Ireland. A pilot study conducted at University College Cork.

AIMS: To determine the self-assessed continuing professional development (CPD) needs of dental practitioners and identify how each discipline can best be served by a dental CPD programme. To set findings in the context of the available literature and contribute to the development of CPD programmes. METHOD: Topics were arranged into eight disciplines: practice management; paediatric dentistry; preventive dentistry; orthodontics; behaviour management; dentistry for people with a disability; oral medicine and surgery; and, restorative dentistry. A web-based questionnaire was constructed and administered using a MarkClass 2.21 online survey tool. RESULTS: Fifty-six self-reported assessment responses were received, with three-quarters of participants having graduated within the past 10 years. Topics in oral medicine and surgery attracted consistently high levels of interest. A tendency to favour topics with a perceived direct clinical application was observed. Topics recommended by the Dental Council as core areas for CPD were given a high level of priority by respondents. CONCLUSIONS: Traditional lectures remain a valued mode of CPD participation. Practical courses were valued across all dental topics offered. A varied approach to determining the requirements of dentists is essential to appropriately support the practitioner.

Clinical experiences of undergraduate dental students in pediatric dentistry at Cork University Dental School and Hospital, Ireland.

The objectives of this study were to evaluate the number and range of clinical procedures completed by undergraduate dental students in pediatric dentistry in Cork University Dental School and Hospital, Ireland, and to compare the number of procedures undertaken with the subsequent examination scores. The work comprised a retrospective audit of clinical logbooks for all of the undergraduate dental students in one cohort through their fourth and fifth clinical years between 2004 and 2006. Thirty-four quantitative logbooks were audited. Students had seen a total of 1,031 patients, and each student had completed a full course of dental treatment for an average of twenty-two children. Students completed means of 30.2 restorative procedures for children, fourteen in deciduous dentition (range six to twenty-eight), and seventeen in permanent dentition (range seven to twenty-eight). Continuity of education and care (measured through children having their treatment fully completed by the same student) was 72 percent. A moderate positive correlation between levels of clinical experience and exam score was identified. All students gained experience in management of child patients with students providing care for an average of thirty children and a minimum of nineteen.

Occlusal accommodation and mouthguards for prevention of orofacial trauma.

PURPOSE: The aim of this study was to investigate the effect of two types of occlusal accommodation on the arch separation in centric and eccentric arch positions and to assess the opposing tooth contacts in professionally made, thermoformed sports mouthguards. MATERIALS AND METHODS: Maxillary and mandibular alginate impressions, a wax interocclusal record of centric occlusion together with maxillary/condylar face-bow registrations, were recorded clinically for 10 undergraduate dental students who are sports activist volunteers of the School of Medicine and Dentistry, Queen's University Belfast. Two ethylene vinyl acetate thermoformed maxillary mouthguards were made for each player (N = 20) using a standardised procedure. Ten mouthguards served both as the control (i.e. the non-accommodated) group and also the accommodated, occlusally 'imprinted' group. The other 10 mouthguards served as the accommodated, occlusally 'ground' group. Casts were articulated, each non-accommodated and accommodated mouthguard was seated and the extent of the interocclusal opening was recorded in all three arch relationships. The number of mouthguard and mandibular tooth contacts were also recorded in each position. RESULTS: The increased vertical occlusal dimension that was found in the presence of non-accommodated mouthguards equated to the full-sheet thickness of the material that was used to form the mouthguards. Only mouthguards accommodated by grinding retained high levels of occlusal contact in all arch relationships that were tested. CONCLUSIONS: Within the limitations of this study, the modification of the occlusal surface made by flat grinding reduced the arch separation in eccentric movements and increased the opposing tooth contacts in custom-made mouthguards. This may contribute to increased comfort, compliance and the protective effect of these appliances thus resulting in a reduction of injuries to the teeth, arches and soft tissues.

Factors affecting the timing of pulp extirpation in a sample of 66 replanted avulsed teeth in children and adolescents.

The management of 66 replanted avulsed permanent teeth in 46 patients over a 4-year period was studied. Treatment was compared with the recommendations in published guidelines for the management of avulsed permanent teeth. For total extra-alveolar times longer than 45 min, the pulps were extirpated in 96% of teeth. Extra-alveolar times longer than 45 min were associated with earlier pulp extirpation (median 16 days) compared with teeth with shorter extra-alveolar times (median 25 days). Endodontic treatment was postponed in teeth with open apices (median 27 days) compared with closed apices (median 15 days). Teeth in which pulps were removed within 10 days post-trauma had a lower prevalence of inflammatory root resorption compared with teeth in which pulps were removed later. Where inflammatory root resorption did occur, onset was significantly delayed when the pulp had been removed within the first 10 days. This study indicates that clinicians are following the guidelines in key areas of endodontic management of traumatized incisors resulting in more favourable outcomes.

Post thermoforming dimensional changes of ethylene vinyl acetate used in custom-made mouthguards for trauma prevention--a pilot study.

It is important that mouthguards have an adequate thickness of material if they are to be effective in the prevention of trauma. The aim of this study was to quantify dimensional changes that occur on thermoforming ethylene vinyl acetate (EVA) sheets used in the construction of mouthguards. Fourteen batches of 3 mm thick sheet EVA were thermoformed over dental models under a number of common processing conditions including, model height, inclination, shape and model temperature, model position on thermoforming platform, plasticizing time and evacuation method. Thickness of thermoformed material was determined at anterior and posterior sites and measurements were compared to determine the magnitude and patterns of stretching collectively and within each processing condition. Overall, sheets of 3-mm EVA stretched by 52% during the thermoforming conditions tested. Incisal/cuspal sites were found to be significantly thinner when compared with all other locations measured. A number of thermoforming conditions were demonstrated to have a significant effect on the degree to which the EVA material stretched. For the combination of materials and equipment tested in this study, current thermoforming practices may cause excessive thinning of EVA in critical areas including incisal edges and cusp tips, thereby reducing the protective effect for professionally made mouthguards. To optimize protection in vulnerable areas, it is important that clinicians distinguish between EVA sheet thickness and the cross-sectional dimensions achieved in the finished mouthguards. They need to be specific in their prescription of the thickness of material they require especially in critical areas.

The hierarchical cluster analysis of oral health attitudes and behaviour using the Hiroshima University--Dental Behavioural Inventory (HU-DBI) among final year dental students in 17 countries.

OBJECTIVE: To explore and describe international oral health attitudes/ behaviours among final year dental students. METHODS: Validated translated versions of the Hiroshima University-Dental Behavioural Inventory (HU-DBI) questionnaire were administered to 1,096 final-year dental students in 17 countries. Hierarchical cluster analysis was conducted within the data to detect patterns and groupings. RESULTS: The overall response rate was 72%. The cluster analysis identified two main groups among the countries. Group 1 consisted of twelve countries: one Oceanic (Australia), one Middle-Eastern (Israel), seven European (Northern Ireland, England, Finland, Greece, Germany, Italy, and France) and three Asian (Korea, Thailand and Malaysia) countries. Group 2 consisted of five countries: one South American (Brazil), one European (Belgium) and three Asian (China, Indonesia and Japan) countries. The percentages of 'agree' responses in three HU-DBI questionnaire items were significantly higher in Group 2 than in Group 1. They include: "I worry about the colour of my teeth."; "I have noticed some white sticky deposits on my teeth."; and "I am bothered by the colour of my gums." CONCLUSION: Grouping the countries into international clusters yielded useful information for dentistry and dental education.

External inflammatory and replacement resorption of luxated, and avulsed replanted permanent incisors: a review and case presentation.

External inflammatory resorption and replacement resorption are complicating factors that may result from traumatic dental injuries when the tooth is luxated or avulsed and replanted. Resorption may, ultimately, result in loss of the tooth. However, with appropriate treatment, the prognosis for these teeth is greatly improved, with the possibility of preventing or arresting resorption. The purpose of this paper is to review these trauma entities, to discuss factors that influence the occurrence of resorption and to describe the most appropriate treatment. A case is presented, illustrating both resorption entities, but with varying outcomes.

Factors affecting resorption in traumatically intruded permanent incisors in children.

There is a lack of consensus concerning the management of intruded permanent teeth. The objectives of the present study were to determine the prevalence of resorption for intruded permanent teeth and to establish the effect of factors on the timing, prevalence and rate of resorption and to examine the relationship between the timing of onset and the subsequent rate of resorption. Sixty-one intruded permanent incisors treated at the Paediatric Dentistry units in Belfast and Newcastle upon Tyne, during the period 1990-99 with a minimum follow-up period of 1.5 years, were studied. The timing and presence of resorption and its rate of occurrence over time were set as the principal outcomes. There was a significantly earlier onset and higher prevalence of resorption in more severely intruded teeth (P< 0.05). There was also a significant relationship between the degree of apical development and resorption with an increased prevalence in the more fully developed roots (P< 0.001). Resorption was detected significantly earlier in teeth with higher rates of resorption (P< 0.05). However, the treatment method did not significantly affect the prevalence or rate of resorption. In conclusion, the occurrence of root resorption after intrusive trauma appears to be related to the severity of the original injury and the stage of root development rather than the repositioning procedure.