Maternal antioxidant treatment prevents the adverse effects of prenatal stress on the offspring's brain and behavior.

Maternal exposure to stress during pregnancy is associated with an increased risk of psychiatric disorders in the offspring in later life. The mechanisms through which the effects of maternal stress are transmitted to the fetus are unclear, however the placenta, as the interface between mother and fetus, is likely to play a key role. Using a rat model, we investigated a role for placental oxidative stress in conveying the effects of maternal social stress to the fetus and the potential for treatment using a nanoparticle-bound antioxidant to prevent adverse outcomes in the offspring. Maternal psychosocial stress increased circulating corticosterone in the mother, but not in the fetuses. Maternal stress also induced oxidative stress in the placenta, but not in the fetal brain. Blocking oxidative stress using an antioxidant prevented the prenatal stress-induced anxiety phenotype in the male offspring, and prevented sex-specific neurobiological changes, specifically a reduction in dendrite lengths in the hippocampus, as well as reductions in the number of parvalbumin-positive neurons and GABA receptor subunits in the hippocampus and basolateral amygdala of the male offspring. Importantly, many of these effects were mimicked in neuronal cultures by application of placental-conditioned medium or fetal plasma from stressed pregnancies, indicating molecules released from the placenta may mediate the effects of prenatal stress on the fetal brain. Indeed, both placenta-conditioned medium and fetal plasma contained differentially abundant microRNAs following maternal stress, and their predicted targets were enriched for genes relevant to nervous system development and psychiatric disorders. The results highlight placental oxidative stress as a key mediator in transmitting the maternal social stress effects on the offspring's brain and behavior, and offer a potential intervention to prevent stress-induced fetal programming of affective disorders.

The Dental Amalgam Phasedown in New Zealand: A 20-year Trend.

BACKGROUND AND OBJECTIVES: Information on the choice of material and performance of restorations placed in a dental practice annually is limited. The Minamata Convention on Mercury is likely to affect the use of amalgam worldwide. The objective of this research was to investigate the use of restorative materials at the University of Otago Faculty of Dentistry in New Zealand from 1998 to 2017. METHODS: Data from the Faculty of Dentistry's database from the years of interest were compiled. These data included information on the characteristics of restorations, including information on the material used and number of surfaces involved for each restoration. The tooth in which each restoration was placed was categorized by arch, tooth type, and deciduous or permanent dentition. RESULTS: Records identified 227,514 permanent restorations placed from January 1998 to December 2017, of which 91.7% were direct restorations. Among direct restorations, composite resin was the most commonly used material, followed by amalgam, glass ionomer, and compomer. The use of amalgam for direct restorations decreased from 52.3% of direct restorations in 1998 to 7.1% in 2017. A corresponding increase was observed in the use of tooth-colored direct restorations, particularly composites. Among indirect restorations, porcelain fused to metal, gold, and stainless steel (in pediatric applications) were the materials most frequently used. CONCLUSIONS: Despite having no official policy on reducing the use of dental amalgam, the Faculty of Dentistry is following the global trend in reducing its use, with composite resin now well established as the predominant restorative material used. If the current rate of decline persists unchecked, the Faculty of Dentistry could transition to being amalgam free by 2020, although it seems likely that the characteristics and principles of use of the material (and its removal) will be taught for some time to come. This knowledge is important to planning curriculum changes needed to prepare graduates for clinical practice.

Antenatal dexamethasone treatment transiently alters diastolic function in the mouse fetal heart.

Endogenous glucocorticoid action is important in the structural and functional maturation of the fetal heart. In fetal mice, although glucocorticoid concentrations are extremely low before E14.5, glucocorticoid receptor (GR) is expressed in the heart from E10.5. To investigate whether activation of cardiac GR prior to E14.5 induces precocious fetal heart maturation, we administered dexamethasone in the drinking water of pregnant dams from E12.5 to E15.5. To test the direct effects of glucocorticoids upon the cardiovascular system we used SMGRKO mice, with Sm22-Cre-mediated disruption of GR in cardiomyocytes and vascular smooth muscle. Contrary to expectations, echocardiography showed no advancement of functional maturation of the fetal heart. Moreover, litter size was decreased 2 days following cessation of antenatal glucocorticoid exposure, irrespective of fetal genotype. The myocardial performance index and E/A wave ratio, markers of fetal heart maturation, were not significantly affected by dexamethasone treatment in either genotype. Dexamethasone treatment transiently decreased the myocardial deceleration index (MDI; a marker of diastolic function), in control fetuses at E15.5, with recovery by E17.5, 2 days after cessation of treatment. MDI was lower in SMGRKO than in control fetuses and was unaffected by dexamethasone. The transient decrease in MDI was associated with repression of cardiac GR in control fetuses following dexamethasone treatment. Measurement of glucocorticoid levels in fetal tissue and hypothalamic corticotropin-releasing hormone (Crh) mRNA levels suggest complex and differential effects of dexamethasone treatment upon the hypothalamic-pituitary-adrenal axis between genotypes. These data suggest potentially detrimental and direct effects of antenatal glucocorticoid treatment upon fetal heart function.

Neuroimmunology of the female brain across the lifespan: Plasticity to psychopathology.

The female brain is highly dynamic and can fundamentally remodel throughout the normal ovarian cycle as well as in critical life stages including perinatal development, pregnancy and old-age. As such, females are particularly vulnerable to infections, psychological disorders, certain cancers, and cognitive impairments. We will present the latest evidence on the female brain; how it develops through the neonatal period; how it changes through the ovarian cycle in normal individuals; how it adapts to pregnancy and postpartum; how it responds to illness and disease, particularly cancer; and, finally, how it is shaped by old age. Throughout, we will highlight female vulnerability to and resilience against disease and dysfunction in the face of environmental challenges.

Dental practice in the UK in 2015/2016. Part 3: aspects of indirect restorations and fixed prosthodontics.

Objective: This paper reports data which helps identify changes and trends in the provision of indirect fixed prostheses in general dental practice in the UK. To determine by means of an anonymous, self-report questionnaire, the current trend in the provision of fixed prosthodontic treatments, with a special emphasis on the choice of treatment modalities, techniques and materials. Methods: The data presented were extracted from the data obtained from a validated,121-question questionnaire distributed at random to general dental practitioners in the UK attending postgraduate meetings in 2015/2016, with a wide distribution of locations. Results: A response rate exceeding 66% was achieved. Amalgam and light-cured composite were the preferred material for core build-up of vital teeth for around 62% of the respondents. Dentine pins were still being used by 66% of the respondents. The vast majority of respondents (92%) used a post and core to restore root-treated teeth. Fibre posts were the most commonly used (63%) type of preformed post among the respondents. Using the opposing and adjacent teeth as a reference to control tooth structure reduction during vital tooth preparation was the most common method, used by 42% of the respondents. Addition-cured silicone impression materials were the most frequently used impression material (78%). The surveyed practitioners were equally split between precious and non-precious metals as the substructure for indirect restorations. Glass-ionomer luting cements (47%) and resin-based cements (52%) were the most commonly used to cement porcelain fused to metal and zirconia indirect restorations, respectively. Laboratory made aesthetic veneers were prescribed by half of the respondents, while a third of them preferred direct resin composite as a veneer material. Conclusion: Within the limitations of the study, it was concluded that there has been an increase in the use of adhesive bonding and metal-free restorations. Amalgam and dentine pinscontinued to be used, contrary to international trends. Studies of the type reported are considered important in investigating trends and developments in dentistry.

Contemporary dental practice in the UK. Part 1: demography and practising arrangements in 2015.

Objectives: To determine, by means of an anonymous, self-reported questionnaire, the demographic profile and practising details of general dental practitioners in the UK in 2015. Methods: A previously-piloted and validated 121-question questionnaire was distributed during 2015 to 500 dentists at UK dental meetings with a request that they complete the questionnaire and return it by post in the reply-paid envelope to the corresponding author. Results: Three hundred and eighty-eight useable questionnaires were returned, giving aresponse rate of 77.6%. Of the respondents, 60.2% were male and 39.8% female. Theirmean age since graduation was 19.7 years. Just over half of the respondents (50.9%) replied that they were practice principals, 35.8% were associates and 10.6% were foundation dentists. A quarter of the respondents were in single-handed practices, the remainder being in a partnership or group practice. There was a mean of 4.2 dentists per practice, while the mean number of dental therapists in each practice was 0.3 and 1.2 hygienists. Regarding the first available NHS appointment in the respondents' practices for non-urgent care, 23.4% could provide this on the same day, the equivalent figure for private care being 40.1%. The mean percentage of patients receiving NHS treatment was 50%, with 33.8% receiving private treatment. Just over half of respondents considered that Care Quality Commission inspections were 'valuable for fostering patient trust and confidence in dental care.' The collected data indicated that 55.4% of respondents had an intra-oral camera, while, with regard to recently-introduced concepts and techniques, 80.4% used nickel-titanium files, 47.4% used zirconia-based bridgework and 24.9% used tricalcium silicate. Of great interest, perhaps, is the response to digital radiography/digital imaging, with the results indicating that 74.1% of respondents used this form of radiography. Regarding checking the light output of the light curing units, 53.1% stated that they did check the output, but in some cases this might be at a six-monthly interval. Conclusion: Results from this survey indicated that NHS service provision has dropped toapproximately 50% amongst the respondents. Regarding the staffing of dentalpractices, just over half the respondents were practice principals and there was a mean of 4.2 dentists per practice. The results also indicated that UK dentists continue to be innovative in the techniques that they employ.

Challenges in clinical teaching investigated: Towards sustainable staff recruitment and retention in dentistry.

PURPOSE: The study was conducted to identify possible factors and potential barriers that affect the retention and recruitment of clinical teaching staff at the Faculty of Dentistry, University of Otago, New Zealand. METHODOLOGY: A short questionnaire survey was distributed to 47 clinical teaching staff to understand the retention strategies and barriers. The collected quantitative and qualitative data were analysed and presented. FINDINGS: The response rate was 96%, with an equal distribution of female and male clinicians. The majority of participants were European New Zealanders. Themes influencing retention strategies were the necessity of formal teaching skills, clinical teaching as a career pathway, pay progression, lack of support and heavy workload. PRACTICAL IMPLICATIONS: Results suggested that generally the respondents to this survey were motivated to give back to their profession through engaging in dental clinical teaching. This study identified that lack of a career development and minimal pay progression are major factors impacting on the retention of clinical teaching staff.

Estimation of jaw-opening forces in adults.

OBJECTIVES: To estimate maximum jaw-opening forces in healthy participants of diverse ancestry and to estimate whether opening forces are associated with sex, age and anthropometric parameters such as height, weight and BMI. SETTING AND SAMPLE POPULATION: One hundred and forty-nine participants aged 20-60 years with overall good oral and general health. Exclusion criteria included myofascial or neck pain, symptomatic temporomandibular joint disorders (TMD), current orthodontic treatment or the absence of a natural dentition. MATERIAL AND METHODS: Jaw-opening forces were measured with an adjustable rigid extra-oral device connected to a 1000 N load cell. Seven attempts were recorded, with 10 seconds interval. Median force values were obtained after discarding the first and last attempt. The height and weight of each participant were measured and recorded, alongside age, sex and ethnicity. RESULTS: Men had greater maximum opening force median values than women (P < .001). Median (IQR) values for women were 41.16 N (30.44) and 79.00 N for men (63.86). Jaw-opening force values were poorly associated with biological and anthropometric parameters. CONCLUSION: In this study, which included a large sample of participants of broad age range and from a demographically diverse background, jaw-opening force values were greater in males than in females; however, force values were poorly associated with biological and anthropometric parameters. Future studies should explore the potential of this method as a screening tool for TMJ disorders and other conditions.

Dental students' and staff perceptions of the impact of learning environment disruption on their learning and teaching experiences.

INTRODUCTION: This project is a qualitative investigation into student and staff experiences of the effect of a major building redevelopment on their Dental School learning and teaching environments. Currently, there is little research exploring the impact of disruptions to the learning environment on students' learning and staff teaching experiences. METHOD: Data were collected in 2016 using an online survey, semi-structured interviews and focus groups with students and staff. Data were analysed using a general inductive approach. RESULTS: Four broad themes emerged as follows: (i) students valued having a space for personal and collaborative work within the Dental School; (ii) both staff and students positioned staff contributions to learning experiences above the role of the physical learning environment; (iii) the majority of staff and students not feel that the physical environment limited their clinical training; and (iv) staff and students were able to adapt to the impact of building redevelopment through resilience and organisation. DISCUSSION: Results of this research have informed the provision of collegial spaces at the School, both as the building redevelopment continues, and in planning for the completed building.

Criteria for the Replacement of Restorations: Academy of Operative Dentistry European Section.

The replacement of a restoration is one of the most common procedures in dentistry. However, the criteria for such intervention, excluding catastrophic failure and persistent discomfort and pain, continue to be the subject of considerable debate. The decision-making process remains subjective on the part of the treating clinician, while the evidence base for refurbishment and repair rather than replacement for the management of defective and failing restorations continues to grow and strengthen. This article, prepared as an Academy of Operative Dentistry European Section consensus publication, reviews existing criteria for the replacement of restorations and encourages practitioners to shift, if not already doing so, to considering the replacement of a restoration as a last resort rather than as a prudent action to be taken if in any doubt about clinical acceptability. Further research in the area, spanning the risk assessment of defective and failing restorations and new diagnostic tools and processes, together with work to enhance the evidence base of restoration repair vs replacement, would be of immense value.

Ethnic and socioeconomic inequalities in dental treatment at a school of dentistry.

BACKGROUND AND OBJECTIVES: Health services should be targeted toward those most in need of health care. Poor oral health disproportionately affects Maori, Pacific Island, and socioeconomically deprived New Zealanders of all ages, and oral health care services should be prioritised to such groups. In New Zealand, free oral health care is available for all children up to the age of 17. On the other hand, adult dental services are provided on a user-pays basis, except for a limited range of basic services for some adults, access to which varies regionally. This study investigated the extent of dental treatment inequalities among patients at New Zealand's only School of Dentistry. METHODS: Data were audited for all treatments provided at the University of Otago Faculty of Dentistry from 2006 to 2011 for patients born prior to 1990. Ethnic and socioeconomic inequalities in the provision of dental extractions, endodontic treatment, crowns, and preventive care were investigated. Differences were expressed as the odds of having received one or more treatments of that type during the six-year period 2006 to 2011. RESULTS: Data were analysed for 23,799 individuals, of whom 11,945 (50.2%) were female, 1,285 (5.4%) were Maori and 479 (2.0%) were Pacific, 4,040 (17.0%) were of low socioeconomic status (SES), and 2,681 (11.3%) were beneficiaries or unemployed. After controlling for SES, age, and sex, Maori had 1.8 times greater odds of having had a tooth extracted than NZ European patients, while Pacific Islanders had 2.1 times the odds. Furthermore, after controlling for ethnicity, age, and sex, low-SES patients had 2.4 times greater odds of having had a tooth extracted than high-SES patients, and beneficiaries had 2.9 times the odds. Conversely, these groups were less likely to have had a tooth treated with a crown or endodontics or receive preventive care. CONCLUSIONS: Existing policies call for the reduction of inequalities. There is a need for a strategy to monitor changes in treatment inequality over time which includes improving equity in service care provision. The observed treatment inequalities are likely to be an underestimate of those occurring in private dental practice in New Zealand.

Bulk dentine replacement versus incrementally placed resin composite: A randomised controlled clinical trial.

OBJECTIVE: This randomized controlled clinical trial compared two techniques and materials for restoring carious teeth-Bulk dentine replacement versus incremental placement of a hybrid posterior resin composite material in terms of patient comfort (post operative sensitivity and tenderness on biting). MATERIAL AND METHODS: Seventy-two carious teeth were randomized to one of two treatment groups: Group A-were restored with a bulk dentine replacement material or Group B-restored with incrementally placed hybrid composite. Patients were followed up by way of a structured phone call at day 2 and day 7 post-operatively. Patients reporting discomfort at day 7 were subsequently followed up on days 14, and 30. RESULTS: All patients were followed up. At day 2, 18/72 restored teeth had post-operative sensitivity; this figure fell to 10/72 at day 7. A Chi squared test revealed that at day 2 a greater level of sensitivity was reported by patients in Group A (P=0.029). However, at day 7 there was no statistically significant difference between the two groups in terms of sensitivity (P=0.453). 8/72 and 6 /72 teeth had tenderness to biting at days 2 and 7 respectively. A Chi squared test revealed no statistically significant difference between the two groups in terms of tenderness on biting at any time period (P=0.722). Interestingly, Class I cavities were found to be more tender on biting than Class II cavities. At day 30 2/72 teeth exhibited sensitivity and none of the teeth exhibiting tenderness on biting. CONCLUSION: At day 7 there was no significant difference between the two groups in terms of postoperative sensitivity and tenderness on biting.

Sex-Dependent Effects of Prenatal Stress on Social Memory in Rats: A Role for Differential Expression of Central Vasopressin-1a Receptors.

Prenatal stress (PNS) affects a number of traits in the offspring, including stress axis regulation, emotionality and cognition; however, much less is known about the effects of PNS on social memory and the underlying central mechanisms. In the present study, we investigated social preference, social memory under basal and stress conditions and olfactory memory for social and nonsocial odours in the adult offspring of dams exposed to social stress during late pregnancy. Given the key roles that the central oxytocin and vasopressin systems play in facilitating social memory, we further investigated the effects of PNS on the central expression of mRNA for oxytocin (Oxtr) and vasopressin-1a (Avpr1a) receptors. PNS did not affect social preference in either sex; however, social memory was impaired under basal conditions in PNS females but not PNS males. Accordingly, Avpr1a mRNA expression in the lateral septum and bed nucleus of stria terminalis (BNST) was unaltered in males but was significantly lower in PNS females compared to controls. No differences in Oxtr mRNA expression were detected between control and PNS offspring in either sex in any of the brain regions examined. Social memory deficits in PNS females persisted when social odours were used; however, this does not appear to be a result of impaired olfaction because memory for nonsocial odours was similar in control and PNS females. Under acute stress conditions, deficits in social memory were observed in both male and female control offspring; however, PNS males were unaffected. Moreover, acute stress facilitated social memory in PNS females and this was associated with an up-regulation of Avpr1a mRNA in the lateral septum and BNST. Our data support a role for altered signalling via central Avpr1a in PNS-induced sex-dependent changes in social memory and may have implications for understanding the aetiology of neurodevelopmental disorders characterised by social behaviour deficits in humans.

Assessment of efficacy and post-bleaching sensitivity of home bleaching using 10% carbamide peroxide in extended and non-extended bleaching trays.

AIM: This study aimed to compare the effect of extended margin and conventional bleaching trays on tooth bleaching and tooth sensitivity. METHOD AND METHODS: Twenty subjects (18-56 years) were investigated in a split arch design clinical study that was conducted in a general dental practice. Each subject received a custom made bleaching tray and 10% carbamide peroxide gel. The bleaching trays had the borders extended 5 mm beyond the gingival margins on the right side and finished just at the gingival margin on the left side. Shade change and tooth sensitivity were the primary outcomes studied and analysed in this study. The shade of the six upper and lower anterior teeth was assessed using a value-ordered shade guide before, one week and two weeks after treatment. Sensitivity was self-assessed using a visual analogue scale (VAS) at the end of the first and second weeks of the study. RESULTS: At the end of week two, the mean shade change was 5.01 (± 3.37) and 5.10 (± 3.36) for teeth covered by extended and non-extended tray design, respectively. The mean VAS sensitivity scores for teeth covered by extended and non-extended tray design were 0.96 (± 1.39) and 0.66 (± 0.96), respectively. There was no significant statistical difference between the two designs at any assessment point with regard to shade change and sensitivity (p >0.05). CONCLUSIONS: It can be concluded that an extended tray design confers no superior effect in terms of the whitening outcome achieved or in reducing levels of sensitivity. Thus, both tray designs can be used depending on a dentist's personal preference.

Programming the brain and behaviour by early-life stress: a focus on neuroactive steroids.

Animal studies have amply demonstrated that stress exposure during pregnancy or in early postnatal life can adversely influence brain development and have long-term 'programming' effects on future brain function and behaviour. Furthermore, a growing body of evidence from human studies supports the hypothesis that some psychiatric disorders may have developmental origins. Here, the focus is on three adverse consequences of early-life stress: dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, heightened anxiety behaviour and cognitive impairments, with review of what is known about the underlying central mechanisms. Neuroactive steroids modulate neuronal activity and play a key role in neurodevelopment. Moreover they can negatively modulate activity of the HPA axis, exert anxiolytic actions and influence cognitive performance. Thus, neuroactive steroids may provide a link between early-life stress and the resultant adverse effects on the brain and behaviour. Here, a role for neuroactive steroids, in particular the 5α-reduced/3α-hydroxylated metabolites of progesterone, testosterone and deoxycorticosterone, is discussed in the context of early-life stress. Furthermore, the impact of early-life stress on the brain's capacity to generate neurosteroids is considered and the evidence for an ability of neuroactive steroids to over-write the negative effects of early-life stress on the brain and behaviour is examined. An enhanced understanding of the influence of early-life stress on brain neurosteroid systems could aid the identification of new targets for developing treatments for stress-related conditions in humans.

The impact of CBCT imaging when placing dental implants in the anterior edentulous mandible: a before-after study.

OBJECTIVES: To evaluate the impact of CBCT imaging when placing dental implants in the anterior edentulous mandible, using a "before-after" study design. METHODS: Eight dental practitioners, who regularly place dental implants in independent dental practice in the North West of England, were presented with realistic simulations of four edentulous cases. The practitioners were asked to assess case difficulty, select implants and then drill osteotomies in preparation for dental implants in the lower canine regions to support a complete overdenture. In the "before" part of the study, a panoramic and a trans-symphyseal view were available. In the "after" part of the study, a CBCT image was added. Perception of case difficulty, implant selection and the incidence of perforations or "near miss perforations" of the lingual cortical plate were recorded. Two cases were regarded as "regular" and two as "challenging". RESULTS: In challenging cases, the availability of CBCT led practitioners to select narrower implants and to assess cases as more difficult. In the challenging cases only, there were fewer perforations of the lingual cortical plate after the availability of CBCT, but this difference was not statistically significant. There were no perforations in the regular cases either before or after the availability of CBCT. CONCLUSIONS: Perception of case difficulty and implant selection are of importance only if they change the outcome for the patient. This study provided weak evidence that CBCT is helpful in avoiding perforations in challenging cases. The availability of CBCT had no impact in regular cases.