Investigating the vascularization capacity of a decellularized dental pulp matrix seeded with human dental pulp stem cells: in vitro and preliminary in vivo evaluations.

AIM: To investigate the vascularization capacity of a decellularized dental pulp matrix (DDP) of bovine origin seeded with human dental pulp stem cells (hDPSCs) in vitro and to present preliminary in vivo findings. METHODOLOGY: Bovine dental pulps were decellularized and then analysed using histological staining and DNA quantification. The resultant DDPs were characterized using immunohistochemical staining for the retention of vascular endothelial growth factor A (VEGF-A) and fibroblast growth factor 2 (FGF-2). Furthermore, DDPs were recellularized with hDPSCs and analysed histologically. The expression of markers involved in angiogenesis by hDPSCs colonizing the DDPs was assessed in vitro. A preliminary in vivo study was then conducted in which hDPSCs-seeded and unseeded DDPs were inserted in debrided human premolars root slices and implanted subcutaneously in immunodeficient mice. Samples were retrieved after 30 days and analysed using histological and immunohistochemical staining. The independent samples t-test, analysis of variance and a Kruskal-Wallis test were used to analyse the quantitative data statistically depending on the group numbers and normality of data distribution. The difference between the groups was considered significant when the P-value was less than 0.05. RESULTS: Acellular dental pulp matrices were generated following bovine dental pulp decellularization. Evaluation of the developed DDPs revealed a significant DNA reduction (P < 0.0001) with preservation of the native histoarchitecture and vasculature and retention of VEGF-A and FGF-2. Upon recellularization of the DDPs with hDPSCs, the in vitro analyses revealed cell engraftment with progressive repopulation of DDPs' matrices and vasculature and with enhanced expression of markers involved in angiogenesis. In vivo implantation of root slices with hDPSCs-seeded DDPs revealed apparent vascularization enhancement as compared to the unseeded DDP group (P < 0.0001). CONCLUSIONS: The developed decellularized dental pulp matrix had pro-angiogenic properties characterized by the retention of native vasculature and angiogenic growth factors. Seeding of hDPSCs into the DDP led to progressive repopulation of the vasculature, enhanced expression of markers involved in angiogenesis in hDPSCs and improved in vivo vascularization capacity. The se suggest that a combination of DDP and hDPSCs have the potential to provide a promising vascularization promoting strategy for dental pulp regeneration.

Dental trauma experience and oral-health-related quality of life among university students.

BACKGROUND: This study aimed to investigate the impact of self-reported dental trauma on oral-heath-related quality of life (OHRQoL) of young adults and determine whether personality characteristics influenced how it was reported. METHOD: A cross-sectional study was carried out using a sample of 435 university students. A questionnaire sought data on previous dental trauma. OHRQoL was assessed using the short-form of the oral health impact profile (OHIP-14); the outcome being one or more impacts occurring 'fairly often'/'very often'. Personality was assessed using the Positive and Negative Affect Scale (PANAS). RESULTS: The participation rate was 87.2%. Dental trauma experience was reported by 110 participants (25.3%), and 242 (55.6 %) indicated previous dental caries experience. Among those with dental trauma history, one or more OHIP-14 impacts was reported by 29.1% (with 21.2% among those with no history). Impact prevalence was higher among those who had previous dental caries experience (29.8%) than among those who had not (14.7%; P < 0.001). Higher PANAS negative affect scores were observed among those reporting one or more OHIP-14 impacts (P < 0.001). CONCLUSION: While dental trauma does not appear to have a negative impact on OHRQoL in young adults, past dental caries experience does. Negative emotionality influences self-reported oral health.

An absolute sodium abundance for a cloud-free 'hot Saturn' exoplanet.

Broad absorption signatures from alkali metals, such as the sodium (Na I) and potassium (K I) resonance doublets, have long been predicted in the optical atmospheric spectra of cloud-free irradiated gas giant exoplanets1-3. However, observations have revealed only the narrow cores of these features rather than the full pressure-broadened profiles4-6. Cloud and haze opacity at the day-night planetary terminator are considered to be responsible for obscuring the absorption-line wings, which hinders constraints on absolute atmospheric abundances7-9. Here we report an optical transmission spectrum for the 'hot Saturn' exoplanet WASP-96b obtained with the Very Large Telescope, which exhibits the complete pressure-broadened profile of the sodium absorption feature. The spectrum is in excellent agreement with cloud-free, solar-abundance models assuming chemical equilibrium. We are able to measure a precise, absolute sodium abundance of logεNa = [Formula: see text], and use it as a proxy for the planet's atmospheric metallicity relative to the solar value (Zp/Zʘ = [Formula: see text]). This result is consistent with the mass-metallicity trend observed for Solar System planets and exoplanets10-12.

Effects of environmental tobacco smoke on the oral health of preschool children.

AIMS: This study investigated the association between the prevalence of oral health problems (caries, gingivitis, mucosal pigmentation and enamel defects in one to 5 year-old children exposed and not exposed to environmental tobacco smoke before and/or after birth. Exposure to environmental tobacco smoke (ETS) in childhood may have significant health effects. METHODS: A structured questionnaire was used to collect data on a child's current and previous illnesses, oral health behaviours, dietary habits, parental smoking behaviours and parents' dental history. The intraoral examination recorded dental caries (dmfs), enamel defects, gingival health, melanin pigmentation and soft tissue health. Stimulated saliva was collected. Total sIgA levels were quantified using indirect competitive ELISA with a SalimetricsTM kit. RESULTS: The 44 children (aged 15-69 months) recruited were divided into two groups: ETS and non-ETS (control). There were 22 children in each: 16 who were exposed to ETS during and after gestation were identified as the ETSB subgroup. Participants exposed to ETS were more likely to have had upper respiratory tract and middle ear infections during the neonatal period and had higher mean dmft, mean dmfs, mean percent of surfaces with demarcated opacities and mean GI than the non-ETS participants. The children exposed to ETS before and after birth had the highest occurrence of enamel opacities showed a higher risk for dental caries even though more children in this group used the recommended fluoride toothpaste (1000 ppm fluoride). Mothers who smoked either never breastfed their children or breastfed their children for less than the recommended period of 6 months. Children exposed to ETS were shown to have higher mean total sIgA (µg/ml) than the children in the control group. CONCLUSIONS: Associations between ETS exposure before and after gestation and oral health, including salivary changes in young children were shown in the present study. Dental health professionals should include a question about household smoking in children's dental histories, which would allow opportunities to discuss the impact of smoking on child oral health. Longitudinal oral health studies should include a history of maternal smoking during pregnancy and afterwards.

Effects of zoledronic acid and geranylgeraniol on the cellular behaviour and gene expression of primary human alveolar osteoblasts.

INTRODUCTION: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious complication of bisphosphonate therapy. The mechanism underlying BRONJ pathogenesis is poorly understood. OBJECTIVES: To determine the effects of zoledronic acid (ZA) and geranylgeraniol (GGOH) on the mevalonate pathway (MVP) in osteoblasts generated from the human mandibular alveolar bone in terms of cell viability/proliferation, migration, apoptosis and gene expression. MATERIALS AND METHODS: Primary human osteoblasts (HOBs) isolated from the mandibular alveolar bone were phenotyped. HOBs were cultured with or without ZA and GGOH for up to 72 h. Cellular behaviour was examined using a CellTiter-Blue® viability assay, an Ibidi culture-insert migration assay, an Apo-ONE® Homogeneous Caspase-3/7 apoptosis assay and transmission electron microscopy (TEM). Quantitative real-time reverse transcriptase polymerase chain reaction (qRT2-PCR) was used to determine the simultaneous expression of 168 osteogenic and angiogenic genes modulated in the presence of ZA and GGOH. RESULTS: ZA decreased cell viability and migration and induced apoptosis in HOBs. TEM revealed signs of apoptosis in ZA-treated HOBs. However, the co-addition of GGOH ameliorated the effect of ZA and partially restored the cells to the control state. Twenty-eight genes in the osteogenic array and 27 genes in the angiogenic array were significantly regulated in the presence of ZA compared with those in the controls at one or more time points. CONCLUSION: The cytotoxic effect of ZA on HOBs and its reversal by the addition of GGOH suggests that the effect of ZA on HOBs is mediated via the MVP. CLINICAL RELEVANCE: The results suggest that GGOH could be used as a possible therapeutic/preventive strategy for BRONJ.

An Investigation of the Views of Parents in Otago on Dental Care for Primary School-Aged Children by the Community Oral Health Service Prior to the Introduction of the Hub-Based Clinic System.

BACKGROUND AND OBJECTIVES: Prior to the introduction of the Southern District Health Board's reconfigured Community Oral Health Service in Otago, a project was undertaken with parents to investigate their knowledge, understanding and views of the historical School Dental Service and of the Community Oral Health Service that was being introduced. METHODS: Focus groups were run during 2011 in ten selected schools (parents with children in years 1-8) across two areas in Otago to represent ur ban and rural settings and to represent parents who were already travelling to dental services. RESULTS: Parents valued the traditional School Dental Service in Otago highly, generally agreeing that the service based in schools was accessible and convenient for parents and children. Rural parents who had always taken their children to dental appointments viewed it as a normal process, accepting that there could not be a service located in every school. Parents were aware that facilities were out-of-date. They highlighted the challenges of locating therapists since they started moving from school to school in the later 1990s and felt it was difficult for children seeing different therapists at each recall. There were diverse views on the proposed new system. Some parents felt that school-aged children should go to dental clinics on their own or with peers, while other parents welcomed the opportunity to attend when their child was having health care. CONCLUSION: It appears that the Community Oral Health Services should have an ongoing process to seek the views of parents and children about the service.

The use of radiography in the diagnosis of oral conditions in children and adolescents.

Radiography can serve as a useful aid in the diagnosis of numerous oral conditions, with a place in nearly all of the disciplines of dentistry. As such it can have a beneficial role in caring for the oral health of children and adolescents. The following review discusses the use of radiography in the diagnosis of oral conditions in children and adolescents, with particular reference to the diagnosis of dental caries, dental trauma, growth and development and in other dental scenarios, along with the importance of incidental findings. The risks associated with radiation exposure from the use of radiography are discussed, how these need to be balanced with the possible benefits associated with such use, as well as how risks could be minimised. Summary recommendations are also presented, providing an overview of the use of radiography for oral diagnosis in various clinical scenarios for children and adolescents.

Zoledronic acid and geranylgeraniol regulate cellular behaviour and angiogenic gene expression in human gingival fibroblasts.

The mevalonate pathway (MVP) and the anti-angiogenic effect of bisphosphonates have been shown to play a role in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ). This study determined the effect of the bisphosphonate, zoledronic acid and the replenishment of the MVP by geranylgeraniol on human gingival fibroblasts. Cell viability, apoptosis, morphological analysis using transmission electron microscopy, and gene expression for vascular endothelial growth factor A, bone morphogenic protein 2, ras homologue gene family member B, epiregulin and interferon-alpha were conducted. Results showed cellular viability was decreased in the presence of zoledronic acid and the co-addition of zoledronic acid with geranylgeraniol restored cell viability to control levels. Caspase 3/7 was detected in zoledronic-acid-treated cells indicating apoptosis. Transmission electron microscopy revealed dilation of the rough endoplasmic reticulum with zoledronic acid and the appearance of multiple lipid-like vesicles following the addition of geranylgeraniol. Zoledronic acid significantly (P < 0.05, FR > ± 2) up-regulated vascular endothelial growth factor A, bone morphogenic protein 2, ras homologue gene family member B and epiregulin at one or more time points but not interferon-alpha. Addition of geranylgeraniol resulted in a reduction in the expression of all five genes compared with zoledronic-acid-treated human gingival fibroblasts. The study concluded geranylgeraniol partially reversed the effects of zoledronic acid in human gingival fibroblasts both at the cellular and genetic levels, suggesting the regulation of these genes is mediated via the mevalonate pathway.

Management of the pulp in primary teeth--an update.

Management of the pulpal tissue in primary teeth is a clinical challenge facing dental practitioners on a regular basis. This article reviews the most common treatments used at the present time in the management of the pulp in deciduous teeth. It gives an overview of treatment options and the indications and contra-indications for the different treatment modalities. The evidence behind the medicaments used, their actions and success rates are discussed. Practical guidelines for choosing to retain or extract deciduous teeth and management of the primary tooth pulp with different clinical presentations are discussed. Areas of future research are highlighted.

Influence of dental care on children's oral health and wellbeing.

BACKGROUND: Dental problems in early childhood can have a very significant effect not only on the oral health of young children but on their quality of life and that of their families. Added to this are the long term risks they carry into the permanent dentition. AIM: To review current literature on the management of early childhood caries and its influence on wider oral and general health. RESULTS: Recent studies suggest that the risks for dental caries, periodontal disease, malocclusion and other general health problems including overweight and obesity may be increased in children who have had early childhood caries. Traditional restoration of damaged primary teeth has been shown to have only moderate outcomes depending on the techniques and materials used and the ability of children to cooperate because of age or other factors. CONCLUSIONS: More recent interesting approaches that seal enamel caries, only partially remove carious dentine or attempt to entirely seal carious dentine lesions merit not only discussion but also longer term investigation. With increasing demands on health funding, dentistry must look at how the most appropriate care can be provided to allow children to reach adulthood with healthy permanent dentitions - something that less than half the population currently achieve.

Fluoridation and dental caries severity in young children treated under general anaesthesia: an analysis of treatment records in a 10-year case series.

OBJECTIVE: To compare the severity of dental caries in the primary dentitions of children under 7 years (who received comprehensive restorative treatment under general anaesthesia, GA) from an optimally fluoridated area (0.85 ppmF) and a low-fluoride area (approximately 0.1 ppmF). RESEARCH DESIGN: Consecutive clinical case series: clinical details (diagnoses and the treatments provided) were recorded for children who had received comprehensive dental care under GA between 2000 and 2009. Age, gender, ethnicity, socio-economic status and fluoridation status (determined from the residential address) were also recorded. RESULTS: Of the 1396 treated children, 55.7% came from fluoridated areas and 52.5% were male. On average, children from low-fluoride areas were 2.4 months younger and presented with more decayed deciduous teeth than those from fluoridated areas (4.9 and 3.9 teeth respectively; p<0.0001). For each tooth type, the mean number of carious teeth at presentation was greater among the children from low-fluoride areas. In the multivariate model, the number of deciduous teeth affected by caries was lower among older children, those residing in a fluoridated area and among those seen after 2001. It was higher among those not living in high-SES areas. CONCLUSIONS: Children with severe dental caries had statistically significantly lower numbers of lesions if they lived in a fluoridated area. The lower treatment need in such high-risk children has important implications for publicly-funded dental care.

Validity of the FACT-H&N (v 4.0) among Malaysian oral cancer patients.

To assess the cross-sectional construct validity of the Malay-translated and cross-culturally adapted FACT-H&N (v 4.0) for discriminative use in a sample of Malaysian oral cancer patients. A cross-sectional study of adults newly diagnosed with oral cancer. HRQOL data were collected using the FACT-H&N (v 4.0), a global question and a supplementary set of eight questions ('MAQ') obtained earlier in pilot work. Of the 76 participants (61.8% female; 23.7% younger than 50), most (96.1%) had oral squamous cell carcinoma; two-thirds were in Stages III or IV. At baseline, patients' mean FACT summary (FACT-G, FACT-H&N, FACT-H&N TOI, and FHNSI) and subscale (pwb, swb, ewb, fwb, and hnsc) scores were towards the higher end of the range. Equal proportions (36.8%) rated their overall HRQOL as 'good' or 'average'; fewer than one-quarter rated it as 'poor', and only two as 'very good'. All six FACT summary and most subscales had moderate-to-good internal consistency. For all summary scales, those with 'very poor/poor' self-rated HRQOL differed significantly from the 'good/very good' group. All FACT summary scales correlated strongly (r>0.75). Summary scales showed convergent validity (r>0.90) but little discriminant validity. The discriminant validity of the FHNSI improved with the addition of the MAQ. The FACT-H&N summary scales and most subscales demonstrated acceptable cross-sectional construct validity, reliability and discriminative ability, and thus appear appropriate for further use among Malaysian oral cancer patients.

Elite athletes and oral health.

Elite athletes follow demanding training regimes to achieve optimal performance. Training incorporates strategies which coincide with risk factors for dental caries and erosion. The important role of a disease-free oral cavity for peak performance is often overlooked and oral health may be compromised. This initial exploratory study aimed to identify risk factors for dental caries and erosion in elite triathletes. Questionnaires regarding training, diet and oral health were distributed to a sample of elite triathletes in New Zealand. A further sample of 10 athletes was randomly selected from the Dunedin triathlon club to participate in a clinical oral examination. Sports drinks were consumed by 83.9% of the triathletes while training; for 48.4% consumption of both sports drinks and water was described as 'little sips often, from a bottle'. Eating during training sessions was reported by 93.5% of participants; of those 62.1% ate only during cycling training. Only 3.2% perceived training as high risk to oral health. All clinical examination cases were assessed as high risk for developing caries. The diet of elite triathletes is consistent with a high risk profile for caries and erosion. Future research should be aimed at oral health promotion programs for the athletes, coaches and oral-health providers.

Mineral density of hypomineralised enamel.

OBJECTIVES: To characterize molar-incisor hypomineralisation (MIH) defects of different severities quantitatively and qualitatively using X-ray microtomography (XMT) and to measure the range of reduction in mineral density (MD) of MIH enamel compared with the normal range. METHODS: Ten sound teeth and ten MIH teeth were scanned using a commercial XMT system. Four hydroxyapatite phantoms of different densities were used as calibration standards with each scan. A calibration equation derived from the phantoms with each tooth was used for MD calibration. MD was traced from the cementum-enamel junction (CEJ) to the cusp tip and from the dentine-enamel junction (DEJ) to the outer enamel surface. RESULTS: In sound teeth, MD increased from CEJ to cusp/incisal tip, while in MIH teeth MD dropped from the CEJ to the occlusal region, then increased again at the cusp tip. MD was highest midway between DEJ and outer enamel in sound teeth. In MIH, enamel showed normal thickness and MD was highest near the DEJ and then decreased towards the outer enamel. MD of MIH enamel was on average about 19% lower than sound enamel. The MIH defects seemed to follow the incremental lines of enamel formation. CONCLUSIONS: MIH defects are hypomineralised defects of different severities that follow the natural incremental lines of enamel formation. Cuspal areas are usually only mildly affected and cervical enamel always appears to be sound.

Relationship between laser fluorescence and enamel hypomineralisation.

OBJECTIVES: To study the relation between the mechanical properties of hypomineralised enamel, and its laser fluorescence (LF). METHODS: Five extracted teeth with molar-incisor hypomineralisation (MIH) were sectioned longitudinally through the defects and polished to prepare the hypomineralised enamel for testing. Hardness (H) and elastic modulus (E) of enamel were measured using nanoindentation. Measurement recording started from the cervicoenamel junction and proceeded occlusally in increments of 200 microm. Laser fluorescence readings were taken along the same line and at the same sites using a DIAGNOdent pen. RESULTS: H, E, and LF readings from cervical enamel were within the expected range for normal sound enamel. After log transformation of the H and E measurements to allow for linear correlation analysis, there was a significant and moderately strong inverse correlation between LF and H or E samples (r (between specimens)=0.59, r (between specimens)=0.39, respectively; p<0.001). CONCLUSIONS: This study shows that, in the absence of dental caries, increased DIAGNOdent readings can indicate enamel hypomineralisation. While the increased LF readings in carious enamel are thought to be related to the presence of caries bacterial metabolites, the increased readings in hypomineralised enamel may be related to proteins in the hypomineralised enamel and/or light scattering by the inhomogeneous enamel.

Solitary median maxillary central incisor and normal stature: a report of three cases.

Solitary median maxillary central incisor (SMMCI) is a rare finding. Growth deficiency or other systemic abnormalities may or may not be seen in children with this anomaly. Nevertheless, the growth and development of all children with SMMCI should be closely monitored. This article reports the dental findings of three Chinese girls with SMMCI, but no growth deficiency or other systemic involvement.

Changes in aspects of children's oral-health-related quality of life following dental treatment under general anaesthesia.

OBJECTIVES: This study was intended to examine the treatment-associated change in aspects of oral-health-related quality of life (QoL) among children (and their families) undergoing dental rehabilitation under general anaesthesia (GA). METHODS: The parents or caregivers of a consecutive clinical sample of children receiving comprehensive dental treatment under GA at the University of Otago School of Dentistry, Dunedin, and the Christchurch Oral Health Centre, Christchurch, New Zealand, were interviewed by telephone before and after the treatment. Questions were asked relating to the impact of the condition on the child and the family. The post-treatment questionnaire also sought information related to parental satisfaction with the care provided under GA. RESULTS: The parents or caregivers of 95 children participated in the study: 49 had treatment completed at the University of Otago School of Dentistry; and 46 were treated at the Christchurch Oral Health Centre. The child sample comprised 55.8% males and 44.2% females with a mean age of 5.1 years. Their mean dmft was 8.2. A consistent pattern of improvement was found with each indicator used. Complaints of pain, problems with eating and sleeping, and behaviour concerns showed significant improvements, with 100% improvement for children for whom frequent pre-GA problems associated with eating, sleeping and behaviour were reported. Sixty-six parents had to arrange time away from employment on the day of the GA and almost half of those incurred a loss of income. The majority of parents reported a high degree of satisfaction with the care received. CONCLUSIONS: Treating young children with high disease experience in a single session under GA results in immediate improvement in oral health and aspects of their QoL for both the children and their families.

Surviving male with incontinentia pigmenti: a case report.

Incontinentia pigmenti, or Block-Sulzberger Syndrome, is an X-linked dominant disorder with characteristic skin, hair, eye and tooth abnormalities. It is classically considered a male-lethal disorder with recurrent miscarriages of male foetuses. A few cases of surviving males with incontinentia pigmenti have been reported in the medical literature. This article reports the medical and dental findings of a boy diagnosed with incontinentia pigmenti.