Remineralization potential of dentifrices with calcium sodium phosphosilicate and functionalized tri-calcium phosphate in the deeper incipient carious lesions: An in vitro study.

OBJECTIVES: This study evaluated the remineralization potential of calcium sodium phosphosilicate and functionalized tri-calcium phosphate (f-TCP) dentifrices in deeper incipient carious lesions (ICLs). MATERIALS AND METHODS: Artificial ICLs were created by placing premolars into demineralizing solutions. Teeth were randomly assigned into four groups: calcium sodium phosphosilicate (Group 1), f-TCP (Group 2), 1450 ppm fluoride (Group 3), and distilled water (Group 4), which were subjected to 10-day pH cycling. Mineral density (MD) was assessed using microcomputed tomography (Micro-CT), while hardness (H) and elastic modulus (EM) were assessed using nanomechanical testing. RESULTS: MD % gain was higher in Groups 1-3 than in Group 4. In addition, Groups 1 and 2 exhibited significantly higher MD % gain than Group 3. Also, Groups 1-3 showed significantly higher EM and H values than Group 4 in the outer enamel area; yet, Groups 1 and 2 displayed significantly higher EM and H values than Groups 3 and 4 in the inner enamel. CONCLUSIONS: The MD, EM, and H of ICLs significantly increased with the addition of calcium sodium phosphosilicate or f-TCP to fluoridated dentifrices compared to standard fluoride dentifrices. The added active ingredients remineralized the deeper parts of the ICLs, while remineralization at the lesion surface was similar between tested dentifrices.

Variation in enamel prism size in primate molars.

OBJECTIVE: This study examines whether larger enamel prism diameters accommodate a greater enamel volume from the enamel-dentine junction (EDJ) to the outer-enamel surface (OES) in primate molars, and how prism size relates to enamel thickness and crown location. DESIGN: We assessed variation in enamel prism diameter in relation to crown location and enamel thickness in catarrhine lower molars (n = 14 species) and one platyrrhine. Prism diameter and enamel thickness were recorded in four locations (lingual lateral; lingual cuspal; buccal cuspal; buccal lateral), using a buccal-lingual section through the centre of the mesial cusps. Ten prism diameter readings were collected at inner (near the EDJ), outer (near the OES) and middle (between the two locations) enamel for each location. RESULTS: Mean prism diameter values for each species were similar (range: 4.06 µm to 5.81 µm). Prism diameter enlarged from inner to outer enamel, suggesting larger prisms help accommodate the increase in enamel volume from the EDJ to the OES. Average prism diameter does not associate with enamel thickness. Instead, cuspal positions had significantly smaller prism diameter at the EDJ than lateral positions, and larger prism sizes at the OES, leading to an overall similar prism diameter mean for all positions (Lingual lateral: 5.11 µm; Lingual cuspal: 5.04 µm; Buccal cuspal: 4.78 µm; Buccal lateral: 4.99 µm). CONCLUSIONS: Our study revealed consistent average enamel prism diameters in various crown locations of lower primate molars, potentially contributing to the mechanical integrity and functional optimization of enamel in primates.

Tooth chipping patterns and dental caries suggest a soft fruit diet in early anthropoids.

OBJECTIVES: Fossils from the Fayum Depression, Egypt, are crucial for understanding anthropoid evolution due to the abundance of taxa and the time interval they represent (late Eocene to early Oligocene). Dietary and foraging behavioral interpretations suggest fruits were their dominant food source, although hard foods (e.g., seeds and nuts) and leaves could have been important dietary components for particular groups. In this study, we compare dental chipping patterns in five Fayum primate genera with chipping data for extant primates, to assess potential hard object feeding in early anthropoids. MATERIALS AND METHODS: Original specimens were studied (Aegyptopithecus: n = 100 teeth; Parapithecus: n = 72, Propliopithecus: n = 99, Apidium: n = 82; Catopithecus: n = 68); with the number, severity, and position of chips recorded. Dental caries was also recorded, due to its association with soft fruit consumption in extant primates. RESULTS: Tooth chipping was low across all five genera studied, with a pooled chipping prevalence of 5% (21/421). When split into the three anthropoid families represented, chipping prevalence ranged from 2.6% (4/154) in Parapithecidae, 6% (12/199) in Propliopithecidae, and 7.4% (5/68) in Oligopithecidae. Three carious lesions were identified in Propliopithecidae. DISCUSSION: The chipping prevalence is low when compared to extant anthropoids (range from 4% to 40%) and is consistent with a predominantly soft fruit diet, but not with habitual hard food mastication. The presence of caries supports consumption of soft, sugary fruits, at least in Propliopithecidae. Our results add support for low dietary diversity in early anthropoids, with soft fruits as likely dominant food sources.

Before and after: COVID-19 impacts on dental students' well-being, clinical competency and employment opportunities.

INTRODUCTION: The onset of COVID-19 challenged dental schools worldwide, impacting clinical training. In Australasia, New Zealand adopted a COVID-19 'elimination strategy', involving nationwide lockdowns that halted face-to-face education. The 'elimination strategy' adopted at the pandemic onset, which permitted return to 'normal life' in 2021, allowed the pandemic impacts and those related workforce transition to be teased out. This study aimed to evaluate perceived impacts of the COVID-19 pandemic on health and well-being, clinical competency and employment opportunities of dental students. MATERIALS AND METHODS: Two surveys were distributed to final year dental students (n = 94; age range 20-35): one during their final semester and the second six months following graduation. Surveys included open and closed ended questions on participants' self-perceived impacts of COVID-19 on health and well-being, clinical competency and employment opportunities. Average percentages were calculated and descriptive statistics performed. RESULTS: Pre-graduation, participants reported COVID-19 negatively impacted their mental and social health. Slightly lower scores on all dimensions of health post-graduation were likely due to transitioning to the workforce. Pre-graduation, less than half of participants felt prepared to provide the full scope of dental treatment; post-graduation most felt confident to do so. Most participants expected COVID-19 would negatively impact employment opportunities for their cohort, despite all participants being employed when the second survey was conducted. CONCLUSION: Participants self-rated health and clinical competency scores were lower post-graduation when NZ returned to 'normal life', meaning lower scores were related to workforce transition. Dental schools need to be prepared to provide alternative forms of dental education and help mitigate mental health impacts of future major course disruptions.

An Exploration of Mineral Density, Elemental and Chemical Composition of Primary Teeth in Relation to Cord-Blood Vitamin D, Using Laboratory Analysis Techniques.

Postnatally, severe vitamin D deficiency commonly results in rickets as well as potential defects in tooth mineralization. The effects of milder deficiency on oral health outcomes later in life are still unclear. This study used micro-computed tomography (µCT), energy dispersive X-ray analysis (EDX), and Raman spectroscopy to investigate mineral density, total density, and elemental composition of enamel and dentine in 63 exfoliated primary incisors from participants with known 25-hydroxyvitamin D levels (25-OHD) at birth. No differences in mineralization and chemical composition using µCT and EDX analysis were observed irrespective of 25-OHD status. Subtle structural differences were observed via Raman spectroscopy, with more crystalline enamel observed in those with sufficient 25-OHD at birth. Although subtle, the differences seen suggest further attention should be given to children with known milder levels of vitamin D deficiency in early life. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The better to eat you with: morphological disparity and enamel ultrastructure in odontocetes.

Variations in the shape and size of teeth have been associated with changes in enamel ultrastructure across odontocetes. Characterizing these features in extinct taxa can elucidate their functional morphology and feeding strategy, while also shedding light into macroevolutionary patterns during the evolutionary history of cetaceans. This study aimed to (1) describe the enamel and dentine ultrastructure of the Early Miocene odontocetes Notocetus vanbenedeni and Phoberodon arctirostris from Patagonia (Argentina) and (2) quantify tooth and enamel ultrastructure morphological disparity among odontocetes. Enamel was predominantly prismatic, thin in the anterior tooth of N. vanbenedeni and P. arctirostris; whilst thick on the posterior tooth of N. vanbenedeni. Together with skull morphology, data suggests a raptorial feeding strategy for P. arctirostris and a combination suction feeding method for N. vanbenedeni. Statistical analyses supported these inferences, indicating that enamel characters are useful for paleoecological research. Morphological disparity analyses showed that extant odontocetes occupy a larger morphospace and have more disparate morphologies, whilst extinct odontocetes were more similar among each other than with the extant group. There was no clear phylogenetic-based grouping, suggesting that tooth and enamel ultrastructure disparity were mainly driven by ecological pressures. These results highlight enamel ultrastructure as a source for broader-scale paleoecological studies in cetaceans.

A Comparison of the Enamel Remineralisation Potential of Self-Assembling Peptides.

BACKGROUND: The aim of this research was to compare the efficacy of the remineralising potential of self-assembling peptides (SAPs): Curodont Repair (P11-4), P26, and leucine-rich amelogenin peptides (LRAP) with the standard 5% NaF varnish (Duraphat) on early enamel caries lesions (EECLs). METHODS: A demineralising solution (DS) was used to create artificial EECLs in human dental enamel specimens, which were randomly allocated to treatment groups: P11-4; P26 solution; LRAP solution; 5% NaF varnish; and deionised water (DIW). Each specimen was subjected to 8 days of pH cycling. Specimens from each test group were subjected to microcomputed tomography (micro-CT) and nanomechanical testing to assess mineral density (MD), hardness (H), and elastic modulus (EM) properties of sound, demineralised, and treated enamel. RESULTS: The mean MD percentage gain was highest in the P26 and P11-4 groups, followed by the LRAP, 5% NaF varnish, and DIW groups. There were statistically significant differences amongst groups. In the outer layer of EECLs, the EM and H were highest in P26 and P11-4 groups, followed by the LRAP and 5% NaF varnish. In the inner layer of EECLs, the EM and H were highest in P11-4 and P26 groups, indicative of enhanced penetration and remineralisation of the deeper parts of the artificial EECLs. CONCLUSIONS: P26 and P11-4 SAPs are more effective than 5% NaF varnish in remineralising the depth of EECLs.

Variation in enamel mechanical properties throughout the crown in catarrhine primates.

Enamel mechanical properties vary across molar crowns, but the relationship among mechanical properties, tooth function, and phylogeny are not well understood. Fifteen primate lower molars representing fourteen taxa (catarrhine, n = 13; platyrrhine, n = 1) were sectioned in the lingual-buccal plane through the mesial cusps. Gradients of enamel mechanical properties, specifically hardness and elastic modulus, were quantified using nanoindentation from inner (near the enamel-dentine junction), through middle, to outer enamel (near the outer enamel surface) at five positions (buccal lateral, buccal cuspal, occlusal middle, lingual cuspal, lingual lateral). Cuspal positions had higher mechanical property values than lateral positions. Middle enamel had higher mean hardness and elastic modulus values than inner and outer locations in all five crown positions. Functionally, the thicker-enameled buccal cusps of lower molars did not show evidence of increased resistance to failure; instead, lingual cusps-which show higher rates of fracture-had higher average mechanical property values, with no significant differences observed between sides. Preliminary phylogenetic results suggest there is relatively little phylogenetic signal in gradients of mechanical properties through the enamel or across the crown. There appears to be common mechanical property patterns across molar crowns in Catarrhini and potentially among primates more broadly. These results may allow more precise interpretations of dental biomechanics and processes resulting in mechanical failure of enamel in primates, such as wear and fracture.

Variation in enamel and dentine mineral concentration and density in primate molars.

OBJECTIVE: Variation in enamel and dentine mineral concentration and total effective density can be reliably collected using Micro-CT scans. Both variables are suggested to reflect mechanical properties such as hardness and elastic modulus in dental tissues, meaning Micro-CT methods allow relative composition and mechanical properties to be collected non-destructively. DESIGN: 16 lower molars from 16 Catarrhine primates were Micro-CT scanned alongside hydroxyapatite phantoms using standardized settings and methods to calculate mineral concentration and total effective density. Mineral concentration, total effective density and thickness of dentine and enamel were calculated for four cusps, representing each 'corner' of the tooth and four lateral crown positions (i.e., mesial, buccal, lingual and distal). RESULTS: The results show mean mineral concentration and total effective density values were higher in areas of thicker enamel, while the opposite was observed for dentine. Buccal positions had significantly higher mineral concentration and total effective density values than lingual areas. Cuspal positions had higher mean values than lateral enamel, for both dentine (mineral concentration cuspal: 1.26 g/cm3; lateral: 1.20 g/cm3) and enamel (mineral concentration cuspal: 2.31 g/cm3; lateral: 2.25 g/cm3). Mesial enamel had significantly lower values than other locations. CONCLUSIONS: These common patterns across Catarrhine taxa may be linked to functional adaptations related to optimization of mastication and tooth protection. Variation in mineral concentration and total effective density may also be associated with wear and fracture patterns, and can be used as baseline information to investigate the effect of diet, pathological changes and aging on teeth through time.

A new dolphin with tusk-like teeth from the late Oligocene of New Zealand indicates evolution of novel feeding strategies.

All extant toothed whales (Cetacea, Odontoceti) are aquatic mammals with homodont dentitions. Fossil evidence from the late Oligocene suggests a greater diversity of tooth forms among odontocetes, including heterodont species with a variety of tooth shapes and orientations. A new fossil dolphin from the late Oligocene of New Zealand, Nihohae matakoi gen. et sp. nov., consisting of a near complete skull, earbones, dentition and some postcranial material, represents this diverse dentition. Several preserved teeth are horizontally procumbent, including all incisors and canines. These tusk-like teeth suggest adaptive advantages for horizontally procumbent teeth in basal dolphins. Phylogenetic analysis places Nihohae among the poorly constrained basal waipatiid group, many with similarly procumbent teeth. Features of N. matakoi such as its dorsoventrally flattened and long rostrum, long mandibular symphysis, unfused cervical vertebrae, lack of attritional or occlusal wear on the teeth and thin enamel cover suggest the rostrum and horizontally procumbent teeth were used to injure and stun prey though swift lateral head movements, a feeding mode that did not persist in extant odontocetes.

Genomic evidence for homoploid hybrid speciation in a marine mammal apex predator.

Hybridization is widespread and constitutes an important source of genetic variability and evolution. In animals, its role in generating novel and independent lineages (hybrid speciation) has been strongly debated, with only a few cases supported by genomic data. The South American fur seal (SAfs) Arctocephalus australis is a marine apex predator of Pacific and Atlantic waters, with a disjunct set of populations in Peru and Northern Chile [Peruvian fur seal (Pfs)] with controversial taxonomic status. We demonstrate, using complete genome and reduced representation sequencing, that the Pfs is a genetically distinct species with an admixed genome that originated from hybridization between the SAfs and the Galapagos fur seal (Arctocephalus galapagoensis) ~400,000 years ago. Our results strongly support the origin of Pfs by homoploid hybrid speciation over alternative introgression scenarios. This study highlights the role of hybridization in promoting species-level biodiversity in large vertebrates.

Tooth chipping patterns in Archaeolemur provide insight into diet and behavior.

OBJECTIVES: Archaeolemur is a recently extinct genus of lemur that is often compared to some Cercopithecidae, especially baboons. This is due in part to their derived dentition, with large anterior teeth and reduced bilophodont molars. Research involving comparative morphology, analysis of coprolites, isotopes, and enamel structure, have suggested Archaeolemur had an omnivorous diet involving mechanically challenging items. Yet, microwear analysis of posterior teeth does not necessarily support this conclusion. MATERIALS AND METHODS: In this macroscopic study, dental chipping was recorded on permanent teeth of Archaeolemur from different localities (53 individuals; 447 permanent teeth; including both A. edwardsi and A. majori specimens). This study aimed to compare chipping patterns across the dentition of Archaeolemur with chipping in other primates. RESULTS: The results show enamel chipping was prevalent on the anterior teeth of Archaeolemur (38.9% of anterior teeth showed at least one fracture) yet rare in posterior teeth (9%). There was a decrease in chipping frequency across the dentition, moving distally from incisors (50%; 20/40), through caniniform teeth (30%; 15/50), premolars (9.5%; 16/169), and molars (8.5%; 16/188). DISCUSSION: The results support previous research suggesting Archaeolemur had a varied omnivorous diet in which the anterior dentition was used for extensive food processing. This likely included mechanically challenging items such as tough/hard large fruits, small vertebrates, and crustaceans. Such a high rate of chipping in the anterior dentition is uncommon in other primates, with exception of hominins.

Longitudinal changes in juvenile and adolescent body mass indices before, during, and after the COVID-19 lockdown in New Zealand.

OBJECTIVE: This study uses longitudinal data from school children in Dunedin, New Zealand, to evaluate impacts of COVID-19 lockdown measures on changes in body mass (BMI, kg/m2 ). Impacts are assessed using two non-mutually exclusive hypotheses. The "structured days" hypothesis holds that children tend to alter sleep patterns, reduce activity and increase snacking when not in structured environments. The bidirectional hypothesis proposes that over-weight or obese children are predisposed to further gains in unstructured settings. METHODS: Juveniles and adolescents (n = 95, 60% female) were recruited from Dunedin schools. Repeated measures analyses assessed variation in intra-individual change in BMI during four periods: P1 (before summer break), P2 (during summer break), P3 (during the COVID-19 lockdown), and P4 (after the lockdown ended). The model also examined if these changes were influenced by participants' sex or body size early in the first period assessed using log-transformed BMI, log-transformed weight, height, or lower leg length. RESULTS: Repeated measures analyses of per month gains in BMI (kg/m2 ) during the four periods revealed consistent period (p ≤ .001), period by sex (p ≤ .010), and period by body size (p ≤ .001) interactions across all four body size proxies. Both sexes experienced the greatest gains during the lockdown (P3), but differed in response to their summer break (P2). CONCLUSION: Results are mostly consistent with the "structured days" hypothesis, but challenge the bidirectional hypothesis as defined. Further research better characterizing risks of gains in adiposity are needed.

No one is born with it: Australasian dental students' perceptions of learning manual dexterity.

Dentistry requires high manual dexterity, and few studies have investigated the challenges and impact on dental students of attaining manual dexterity skills. This study aimed to investigate dental students' perceptions of manual dexterity, including their awareness of manual dexterity requirements in dentistry, self-perceptions of manual dexterity competency, and whether manual dexterity should be part of admission to dentistry training. A link to a 12-item online Qualtrics survey was sent out to students in either their 2nd or 5th year of the Bachelor of Dental Surgery (BDS) degree at the University of Otago, New Zealand. The anonymous survey collected basic demographic data and included closed and open-ended questions about manual dexterity. Descriptive statistics were calculated for quantitative variables and a general inductive approach was used to analyze free-text responses. Those were later grouped into a theoretical domain framework. The overall response rate was 53%. All participants acknowledged the importance of manual dexterity in dentistry. Most participants thought that manual dexterity can be improved with practice and that including a manual dexterity test in the admission criteria may cause unnecessary stress for students. Striving to achieve manual dexterity impacted participants' performance in the BDS course. However, most participants viewed it as a challenge that can be overcome with practice and improvement, and that current BDS admission requirements are sufficient.

Enhancing the student learning experience: Co-teaching biochemistry and clinical sciences within the dental curriculum.

Basic knowledge of biochemistry underpins oral and dental care. Undergraduate dental students do not always engage well with basic science teaching due to not appreciating its clinical relevance. Co-teaching provides one approach to overcome students' disengagement and involves two lecturers, with complementary expertise, presenting the curriculum together. This study investigated student experiences and engagement using co-teaching to integrate biochemistry with clinical sciences in the students' second-year dental curriculum. Two successive second year dental student cohorts were co-taught. Content was delivered by a biochemist and an oral biologist, either online (during the 2020 COVID lockdown) or in-person (2021). Each cohort was surveyed at the end of the teaching module using an online questionnaire containing both interval scale and free-text questions. Responses were received from 39 (42%) and 64 (85%) of students in 2020 and 2021, respectively. Students from both cohorts preferred the co-teaching approach with a mean of 8.74 on a 10-point interval scale. In 2020 and 2021, 77% and 76% of participants, respectively, preferred a combined biochemistry and clinical dentistry delivery, either in-person (37%), via Zoom (19%) or via video recording (14%). Thematic analysis of responses revealed students experienced enhanced engagement when co-taught and they attributed this to integration of the curriculum making the content more relevant and stimulating. Students preferred co-teaching to individual subjects being taught by a single teacher. Co-teaching established the relevance of theoretical biochemistry to clinical dental sciences and enhanced the students' learning experience.

Dental biorhythm is associated with adolescent weight gain.

Background: Evidence of a long-period biological rhythm present in mammalian hard tissue relates to species average body mass. Studies have just begun to investigate the role of this biorhythm in human physiology. Methods: The biorhythm is calculated from naturally exfoliated primary molars for 61 adolescents. We determine if the timing relates to longitudinal measures of their weight, height, lower leg length and body mass collected over 14 months between September 2019 to October 2020. We use univariate and multivariate statistical analyses to isolate and identify relationships with the biorhythm. Results: Participants with a faster biorhythm typically weigh less each month and gain significantly less weight and mass over 14-months, relative to those with a slower biorhythm. The biorhythm relates to sex differences in weight gain. Conclusions: We identify a previously unknown factor that associates with the rapid change in body size that accompanies human adolescence. Our findings provide a basis from which to explore novel relationships between the biorhythm and weight-related health risks.

Clinical and Microbiological Evaluation of a Chlorhexidine-Modified Glass Ionomer Cement (GIC-CHX) Restoration Placed Using the Atraumatic Restorative Treatment (ART) Technique.

The aims of this study were to investigate the clinical effectiveness and patient acceptability of a modified glass ionomer cement placed using the atraumatic restorative treatment (ART) technique to treat root caries, and to carry out microbiological analysis of the restored sites. Two clinically visible root surface carious lesions per participant were restored using ART. One was restored with commercial glass ionomer cement (GIC) (ChemFil® Superior, DENTSPLY, Konstonz, Germany) which acted as the control. The other carious root lesion was restored with the same GIC modified with 5% chlorhexidine digluconate (GIC-CHX; test). Patient acceptability and restoration survival rate were evaluated at baseline and after 6 months. Plaque and saliva samples around the test and control restorations were collected, and microbiological analysis for selected bacterial and fungal viability were completed at baseline, and after 1, 3, and 6 months. In total, 52 restorations were placed using GIC and GIC-CHX in 26 participants; 1 patient was lost to follow-up. After reviewing the restorations during their baseline appointments, participants indicated that they were satisfied with the appearance of the restorations (n = 25, 96%) and did not feel anxious during the procedure (n = 24, 92%). Forty-eight percent (n = 12) of the GIC-CHX restorations were continuous with the existing anatomic form as opposed to six for the GIC restorations (24%), a difference which was statistically significant (p = 0.036). There was no statistically significant reduction in the mean count of the tested microorganisms in plaque samples for either type of restorations after 1, 3, or 6 months. Restoration of carious root surfaces with GIC-CHX resulted in higher survival rates than the control GIC. ART using GIC-CHX may therefore be a viable approach for use in outreach dental services to restore root surface carious lesions where dental services are not readily available, and for older people and special needs groups.

Jet injection needle-free dental anaesthesia: Initial findings.

OBJECTIVES: We evaluated patient preference and reported levels of anxiety and discomfort of participants treated with a new needle-free electric motor-driven device vs. conventional local anaesthetic for dental extractions in a proof-of-principle study. Healing and response of gingival tissues to injection were also evaluated at 1, 3- and 7-days post-procedure. METHODS: After informed consent, eight participants who required bilateral maxillary extractions were included in the trial. The side and order of placement for the needle-free and conventional anaesthetic were randomized. The same operator delivered anaesthesia and ensured teeth were anaesthetized on both sides. Another operator, unaware of order and type of anaesthesia placed, performed the extractions. RESULTS: Participant's average discomfort scores were low for both techniques, and lower for the needle-free injection at all timepoints. Needle-free local anaesthesia was the preferred technique by most participants at most timepoints. The average volume of anaesthetic dispensed was similar between techniques. Successful anaesthesia with the needle-free device was achieved in 6 out of 8 participants. Healing of the extraction sockets and adjacent oral mucosa progressed normally for all participants, with no evidence of infection, trauma or hematoma in the injection sites of the test and conventional sides. CONCLUSIONS: The needle-free local anaesthetic technique investigated achieved sufficient anaesthesia for tooth extractions in the maxilla in 75% of the subjects. A larger clinical trial is needed to further validate the technique tested and to investigate whether needle-free local anaesthesia can be successfully applied to the provision of restorative therapy. CLINICAL SIGNIFICANCE: The results of this study can be used by clinicians treating patients who suffer from dental anxiety and needle-phobia.

Dental Consequences of Vitamin D Deficiency during Pregnancy and Early Infancy-An Observational Study.

Vitamin D (25OHD) status during pregnancy is closely correlated with foetal and new-born 25OHD. Calcification for primary teeth begins from the fourth month of intrauterine life and from birth for permanent teeth. Dental consequences of severe 25OHD deficiency are well documented; however, consequences are less documented for milder degrees of 25OHD deficiency. This study examined the dental consequences of vitamin D deficiency/insufficiency during gestation and infancy in a cohort of 81 New Zealand children. Pregnancy and birth data for the children and their mothers and 25OHD status during gestation, birth and at five months were obtained, and dental examinations were conducted. Associations between 25OHD and enamel defects or caries experience were investigated. Of the 81 children, 55% had experienced dental caries and 64% had at least one enamel defect present. Vitamin D insufficiency (25OHD < 50 nmol/L) at all timepoints was not associated with enamel defect prevalence, but during third trimester pregnancy it was associated with an increased caries risk IRR of 3.55 (CI 1.15-10.92) by age 6. In conclusion, maternal 25OHD insufficiency during the third trimester of pregnancy was associated with greater caries experience in primary dentition. No association was found between early life 25OHD and enamel defect prevalence or severity.

"It's just inappropriate": Harassment of dental students by patients.

INTRODUCTION: Harassment is an issue that occurs in all workplaces and institutions. Due to increased exposure to patients, higher rates of harassment are experienced in health care systems. Health care workers need to form a professional relationship with patients to attend to their health care needs; however, harassment by patients can disrupt this relationship and have detrimental physical, mental, and emotional impacts on the health practitioner. OBJECTIVE: The purpose of this study was to examine the prevalence and impact of harassment by patients toward clinical students at a prominent Australasian dental school. METHODS: A 14-item survey was distributed to clinical students. The survey collected basic demographic information and contained Likert-scale closed questions on harassment prevalence and experience and a free text question asking for details of a significant harassment experience. Descriptive statistics and analysis of free text data were performed. RESULTS: The response rate was 67%. About 20% of respondents reported experiencing at least one incident of harassment. Verbal harassment was most commonly reported, followed by sexual and racial harassment. All incidences of sexual harassment were reported by female students, while racial harassment was most frequently reported by students of Asian ethnicity. Most students indicated they were unsure of how to respond to harassment by patients. CONCLUSION: Dental students were exposed to harassment by patients. IMPLICATIONS: Appropriate policies and education on responding to harassment, alongside support for the same, could help ensure the safety and wellbeing of students.