Association of dental hypersensitivity and anxiety in children with molar-incisor hypomineralisation (MIH).

AIM: The objective of this study was to investigate whether dental hypersensitivity and dental fear were linked to the presence and severity of MIH. METHODS: For this cross-sectional study, 1830 students between the ages of 6 and 12 years were recruited from four randomly selected schools. The Children's Fear Survey Schedule-Dental Subscale questionnaire was used to assess dental anxiety and fear. The children's self-reported dental hypersensitivity resulting from MIH was evaluated using the Wong-Baker Facial Scale and the Visual Analog Scale (VAS). RESULTS: MIH was correlated with tooth hypersensitivity, particularly in severe cases. Dental fear was present in 17.4% of the children with MIH, but it was not associated with dental hypersensitivity, gender, or age. CONCLUSION: No association was found between dental fear and dental hypersensitivity in children with MIH.

Utilising surface-level data to explore surface, tooth, individual and family influence on the aetiology of hypomineralised second primary molars.

OBJECTIVES: Hypomineralised second primary molars (HSPM) are common developmental enamel defects. The aims of this study were to use surface-level data to explore the clustering of HSPM at four levels (family, child, tooth, surface). METHODS: This study of 172 twin pairs was nested within the Peri/postnatal Epigenetic Twin Study. HSPM was measured by standardised oral examinations at age 6 years. Multilevel logistic regression models were fitted to assess the correlation structure of surface level data and variation in HSPM. The associations between surface level risk factors and HSPM were then explored using the multilevel logistic regression model using the best fitting correlation structure. RESULTS: The prevalence of HSPM was 68 (19.8%) children, with a total of 141 (10.3%) teeth and 264 tooth surfaces (6.3%) affected. Multilevel models revealed that a hierarchical structure accounting for correlation at the family, child and tooth level best accounted for the variation in HSPM. The estimated variances from the best fitting model (Model 3) were largest at the family level (12.27, 95% CI 6.68, 22.51) compared with 5.23 at the child level and 1.93 at the tooth level. Application of regression analysis utilising this three-level correlation structure identified tooth/surface level factors in addition to the previously identified familial and individual risk factors for HSPM. CONCLUSION: In addition to familial (environmental and genetic) and unique child-level factors, the aetiology of HSPM is likely to be influenced by local tooth-level factors.

Using Proanthocyanidin as a Root Dentin Conditioner for GIC Restorations.

Glass ionomer cements (GICs) are considered the material of choice for restoration of root carious lesions (RCLs). When bonding to demineralized dentin, the collapse of dentinal collagen during restorative treatment may pose challenges. Considering its acidic nature and collagen biomodification effects, proanthocyanidin (PAC) could be potentially used as a dentin conditioner to remove the smear layer while simultaneously acting to biomodify the dentinal collagen involved in the bonding interface. In this study, 6.5% w/v PAC was used as a conditioner for sound (SD) and laboratory demineralized (DD) root dentin before bonding to resin-modified GIC (FII), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-modified GIC (FVII), or a high-viscosity GIC (FIX). Root dentin conditioned with deionized distilled water (DDW) or polyacrylic acid (PAA) served as controls. Results indicated FII showed higher shear bond strength (SBS) on SD than the other 2 GICs, especially in PAA-conditioned samples; FIX showed significantly higher SBS than FII and FVII on PAA- or PAC-conditioned DD. In each category of GIC, PAA and PAC did not have a significant influence on SBS in most cases compared to DDW except for a significant decrease in PAC-conditioned SD bonded to FII and a significant increase in PAA-conditioned DD bonded to FIX. The bonding interface between GIC and SD was generally more resistant to the acid-base challenge than DD. Although the alterations in failure modes indicated a compromised interfacial interaction between GICs and PAC-treated root dentin, biomodification effects of PAC on dentin were observed from Raman microspectroscopy analysis in terms of the changes in mineral-to-matrix ratio and hydroxyproline-to-proline ratio of dentin adjacent to the bonding interface, especially of DD. Results from this study also indicated the possibility of using in situ characterization such as Raman microspectroscopy as a complementary approach to SBS test to investigate the integrity of the bonding interface.

[Minimally invasive caries management in children: when to use what treatment]. / Minimaal invasief cariësmanagement bij kinderen: wanneer welke strategie?

Children are born with healthy mouths. The goal of primary prevention is to maintain this healthy situation. Starting primary prevention as early as possible, preferably at the moment of eruption of the primary teeth, is recommended. Estimating the caries risk, for example, with the help of a system such as the NOCTP method, is an important tool for deciding the check-up interval, bitewing interval and other care interventions. Prevention is always key. Active lesions may require another treatment, too, in addition to prevention. Inactive lesions as well as cleansable cavitated lesions do not require invasive treatment. Non-cleansable cavitated lesions are candidates for invasive treatment such as slicing as part of a non-restorative caries treatment (NRCT), Hall crowns or conventional restorations. The child's well-being is always the most important factor in choosing the right treatment.

Root canal instrumentation efficacy of non-fused and fused primary molar roots: a micro-computed tomography study.

PURPOSE: Pulpectomy may be indicated in restorable primary teeth exhibiting irreversible pulpitis or pulpal necrosis. The purpose of this study was to compare the cleaning and shaping efficacy of NiTi systems (Reciproc® Blue and MTwo®) with manual stainless-steel instrumentation in primary molars using micro-CT analysis. METHODS: Fifty-seven maxillary second primary molars were scanned using micro-CT. Teeth with three divergent roots were divided randomly (n = 15) according to instrument type (K file, MTwo®, and Reciproc® Blue). Teeth with root fusion were instrumented manually as a separate group (n = 12). Pre- and post-instrumentation micro-CT images were superimposed, and the instrumentation area (IA) and procedural complications were recorded. RESULTS: No statistically significant differences in IA between file systems was observed in the non-fused teeth. The mean IA of fused roots was significantly lower than in the non-fused distobuccal (p = 0.003) and palatal (p < 0.001) roots. The root segment had a significant effect on IA (p < 0.001) and the highest mean IA was observed in the apical third. Manual instrumentation had fewer procedural complications compared with rotary systems. CONCLUSION: No differences were determined in the cleaning and shaping effectiveness of all systems in non-fused teeth. Uninstrumented areas (> 60%) occurred in both non-fused and fused primary teeth with fewer procedural complications observed after manual instrumentation.

[Impact of the coronavirus on Dutch oral health care and practice]. / Impact van het coronavirus op de praktijkvoering van de Nederlandse mondzorg.

Among dental hygienists and dentists in the Netherlands, the impact of the SARS-CoV-2 pandemic on oral healthcare practices from March to July 2020 was investigated. Of the 1,700 healthcare providers approached, 433 completed questionnaires could be used. The results show that the pandemic has had a profound impact on both the accessibility of oral healthcare and on care provided in oral healthcare practices. Extra attention was paid to hygiene and infection prevention: the types of personal protective equipment and the protocols and procedures were adjusted by many oral healthcare providers. The confirmed prevalence of oral healthcare providers with COVID-19 in this study was 1.6%. However, testing was not available to all respondents with complaints during this initial period. Over half of the respondents estimated that even with additional measures there is an increased risk of infection to oral healthcare providers during their work. The efficacy of the various additional measures in oral healthcare practices related to COVID-19 is still unknown.

Root canal morphology of primary maxillary second molars: a micro-computed tomography analysis.

AIM: Successful endodontic treatment of primary teeth requires comprehensive knowledge and understanding of root canal morphology. The purpose of this study was to investigate the root canal configurations of primary maxillary second molars using micro-computed tomography. METHODS: Extracted human primary maxillary second molars (n = 57) were scanned using micro-computed tomography and reconstructed to produce three-dimensional models. Each root canal system was analysed qualitatively according to Vertucci's classification. RESULTS: 22.8% (n = 13) of the sample presented with the fusion of the disto-buccal and palatal roots; of these, Type V was the most prevalent classification. For teeth with three separate roots (n = 44), the most common root canal type was Type 1 for the palatal canal (100%) and disto-buccal canal (77.3%) and Type V for the mesio-buccal canal (36.4%). Overall, 7% (n = 4) of mesio-buccal canals were 'unclassifiable'. CONCLUSION: The root canal systems of primary maxillary second molars were not only complex but had a range of configurations that may contribute to unfavourable clinical outcomes after endodontic treatment.

A twin study of body mass index and dental caries in childhood.

Sub-optimal nutrition and dental caries are both common with significant short and long-term implications for child health and development. We applied twin statistical methods to explore the relationship between body mass index (BMI) and dental caries. We measured BMI at 18 months and six years of age and cumulative dental caries experience at six years in 344 twin children. Dental caries in primary teeth was categorised into 'any' or 'advanced' and BMI was analysed as both a continuous and categorical variable. Statistical analyses included multiple logistic regression using generalized estimating equations and within/between-pair analyses. There was no association between BMI and 'any' dental caries experience at either time-point, neither overall nor in within/between pair analyses. However, 'advanced' dental caries at six years was associated with a within-pair difference in BMI of -0.55 kg/m2 (95% CI -1.00, -0.11, p = 0.015). A within-pair increase of 1 kg/m2 in BMI was associated with a lower within-pair risk of advanced dental caries (OR 0.68, 95% CI 0.52, 0.90, p = 0.007). These findings reveal a possible causal relationship between lower BMI and dental caries. As dental outcomes were only measured at one time point, the direction of this potentially causal relationship is unclear.

Knowledge and Management of First Permanent Molars with Enamel Hypomineralization among Dentists and Orthodontists.

Purpose: Molar Incisor Hypomineralization (MIH) is a developmental enamel anomaly of systemic origin affecting the first permanent molars and often the permanent incisors. Despite MIH being a prevalent anomaly, its diagnosis and management are challenging for practitioners; including poor anesthesia, failure of restorations, rapid enamel breakdown, poor resin adhesion, and related child anxiety. This study aimed to evaluate knowledge regarding and management of MIH amongst orthodontists and dentists. Study design: The study was performed from March to September 2017 and included 336 dentists and 32 orthodontists. Questionnaires comprised questions on MIH diagnosis, socio-demographic characteristics of the subjects, and photographs of a case of MIH with related questions regarding management. Results: Our results showed that 48% of dentists and 25% of orthodontists misdiagnosed MIH; with misdiagnosis associated with graduation prior to 1986 (p < 0.001). Amongst dentists, 59% applied a fluoridated product and 34% applied fissure sealants in the case of moderate MIH. The application of fluoride was associated with graduation after 1986 (p < 0.0001).Conclusion: Large disparities about knowledge and management of MIH exist between dental practitioners in France. Education regarding diagnosis and management of MIH is necessary.

Post-mitotic odontoblasts in health, disease, and regeneration.

OBJECTIVE: Description of the odontoblast lifecycle, an overview of the known complex molecular interactions that occur when the health of the dental pulp is challenged and the current and future management strategies on vital and non-vital teeth. METHODS: A literature search of the electronic databases included MEDLINE (1966-April 2019), CINAHL (1982-April 2019), EMBASE and EMBASE Classic (1947-April 2019), and hand searches of references retrieved were undertaken using the following MESH terms 'odontoblast*', 'inflammation', 'dental pulp*', 'wound healing' and 'regenerative medicine'. RESULTS: Odontoblasts have a sensory and mechano-transduction role so as to detect external stimuli that challenge the dental pulp. On detection, odontoblasts stimulate the innate immunity by activating defence mechanisms key in the healing and repair mechanisms of the tooth. A better understanding of the role of odontoblasts within the dental pulp complex will allow an opportunity for biological management to remove the cause of the insult to the dental pulp, modulate the inflammatory process, and promote the healing and repair capabilities of the tooth. Current strategies include use of conventional dental pulp medicaments while newer methods include bioactive molecules, epigenetic modifications and tissue engineering. CONCLUSION: Regenerative medicine methods are in their infancy and experimental stages at best. This review highlights the future direction of dental caries management and consequently research.

Temporal development of the oral microbiome and prediction of early childhood caries.

Human microbiomes are predicted to assemble in a reproducible and ordered manner yet there is limited knowledge on the development of the complex bacterial communities that constitute the oral microbiome. The oral microbiome plays major roles in many oral diseases including early childhood caries (ECC), which afflicts up to 70% of children in some countries. Saliva contains oral bacteria that are indicative of the whole oral microbiome and may have the ability to reflect the dysbiosis in supragingival plaque communities that initiates the clinical manifestations of ECC. The aim of this study was to determine the assembly of the oral microbiome during the first four years of life and compare it with the clinical development of ECC. The oral microbiomes of 134 children enrolled in a birth cohort study were determined at six ages between two months and four years-of-age and their mother's oral microbiome was determined at a single time point. We identified and quantified 356 operational taxonomic units (OTUs) of bacteria in saliva by sequencing the V4 region of the bacterial 16S RNA genes. Bacterial alpha diversity increased from a mean of 31 OTUs in the saliva of infants at 1.9 months-of-age to 84 OTUs at 39 months-of-age. The oral microbiome showed a distinct shift in composition as the children matured. The microbiome data were compared with the clinical development of ECC in the cohort at 39, 48, and 60 months-of-age as determined by ICDAS-II assessment. Streptococcus mutans was the most discriminatory oral bacterial species between health and current disease, with an increased abundance in disease. Overall our study demonstrates an ordered temporal development of the oral microbiome, describes a limited core oral microbiome and indicates that saliva testing of infants may help predict ECC risk.

Carious lesion management in children and adolescents by Australian dentists.

BACKGROUND: The management of carious lesions in children and adolescents can have lifelong implications for the patient. The aim of this study was to assess the decision-making process of dentists when managing carious lesions in children and adolescents. METHODS: Approximately, 11 000 dentists listed as members of the Australian Dental Association Inc. (ADA) and Australian and New Zealand Society of Paediatric Dentistry (ANZSPD) were emailed a link in April 2017 to a 19-question survey delivered by SurveyMonkey™. RESULTS: In this study, 887 responses were received. In 'enamel-limited' carious lesions, dentists intervened most frequently in primary tooth approximal (365, 41.1%), followed by permanent tooth occlusal (295, 33.3%) and approximal (244, 27.5%), and primary tooth occlusal (203, 22.9%) surface carious lesions. Age, university of graduation, practicing state, decade of graduation and frequency of treatment of children between 6 and 15 years were significant demographic factors influencing the restorative threshold. CONCLUSIONS: Australian dentists reported significant variation in their management of approximal and occlusal carious lesions in both primary and permanent teeth. A substantial proportion of respondents would intervene surgically on non-cavitated enamel-limited lesions.

The impact of MIH/HSPM on the carious lesion severity of schoolchildren from Talca, Chile.

OBJECTIVES: Decamarcated hypomineralised lesions of enamel include those developmental defects that are related to MIH, HSPM or any other demarcated opacities of systemic origin. The present study's aims are to determine MIH/HSPM prevalence, caries lesion severity and their association in a sample of 6-12-year-old schoolchildren from Talca, Chile. METHODS: The sample (N = 577) was derived from selected primary schools in urban Talca. A full dental examination was performed at the school by one calibrated examiner. Socio-demographic data and caries experience (DMFT/dmft/merged ICDAS II and PUFA/pufa) were measured in primary and permanent dentitions. MIH/HSPM was assessed using a modified EAPD protocol. Binary and multilevel binary regression analyses were calculated. RESULTS: The prevalence of MIH/HSPM or other demarcated hypomineralised lesions was 24.4%. MIH and HSPM was 15.8% and 5%, respectively. The presence of HSPM predicted MIH (OR 3.7; 95% CI 1.65-8.15) when corrected by demographic factors. Of the children examined, 35% had no teeth with a score greater than ICDASII Code 0 and 26% had one or more severe carious lesions (Code C). Toothwise multilevel binary regression analyses demonstrated that teeth with MIH/HSPM (OR 3.70) from low-SES children (OR 1.93) had higher odds for carious lesions compared with defect-free teeth from high-SES participants. CONCLUSIONS: MIH/HSPM lesions were associated with carious lesion occurrence and increased disease severity. The prevalence of MIH and HSPM was similar to other reports. Increased awareness of MIH/HSPM in schools and primary health settings may help to identify children at risk early.

Anticariogenic efficacy of a saliva biomimetic in head-and-neck cancer patients undergoing radiotherapy.

BACKGROUND: The aim of this study was to investigate the effect of treatment with the saliva biomimetic, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and SnF2 /NaF compared with SnF2 /NaF alone on coronal surface caries progression in head-and-neck cancer patients undergoing radiotherapy. METHODS: Twenty-four participants were randomized into two groups. Both groups used 0.4% SnF2 gel and a 0.32% NaF toothpaste; the test group also applied a crème containing 10% CPP-ACP three times daily while the control group used an identical crème without CPP-ACP (placebo). Resting saliva flow rate and saliva fluoride concentrations were determined. Caries status was assessed using ICDASII at baseline and 12-weeks postradiotherapy. Data were statistically analysed using a linear mixed effects model. RESULTS: Both groups showed significantly reduced resting saliva flow rate (P < 0.001) postradiotherapy. There were no significant differences in flow rates and fluoride concentration between groups. The CPP-ACP group exhibited a significant (P < 0.05) 51% reduction in coronal surface caries progression compared with the placebo group. CONCLUSION: Resting salivary flow rate was significantly reduced in head-and-neck cancer patients following radiotherapy and use of CPP-ACP with SnF2 /NaF significantly lowered caries progression compared with SnF2 /NaF alone.

Etiology of Hypomineralized Second Primary Molars: A Prospective Twin Study.

The etiology of hypomineralized second primary molars (HSPM) is unclear, but genetic and environmental factors have been proposed. The aim of this study was to investigate the relative contribution of genes and environment to the etiology of HSPM and to identify potential environmental risk factors in a longitudinal twin cohort. Children from twin pregnancies ( N = 250) were recruited antenatally, and detailed demographic, health, and phenotypic data were collected at recruitment, 24- and 36-wk gestation, birth, and 18 mo of age. 25-Hydroxyvitamin D was quantified for mothers at 28-wk gestation and infants at birth. Dental examinations were conducted on the twins at 6 y of age to determine the presence, severity, and extent of HSPM per standardized criteria. To investigate associations of environmental risk factors with HSPM, multiple logistic regression models were fitted with generalized estimating equations to adjust for twin correlation. Within- and between-pair analyses were performed for unshared continuous variables: birthweight and birth 25-hydroxyvitamin D. Twin-twin concordance for monozygotic (MZ) and dizygotic (DZ) pairs was calculated and compared after adjusting for identified risk factors. A total of 344 twins underwent the 6-y-old dental assessment; HSPM occurred in 68 (19.8%). After adjusting for potential confounders, vitamin D levels at birth, infantile eczema, dizygosity, in vitro fertilization, socioeconomic position, and maternal smoking beyond the first trimester of pregnancy demonstrated the strongest associations with HSPM. Overall concordance for HSPM was 0.47 (95% CI, 0.32 to 0.62) with weak evidence ( P = 0.078) of higher concordance in MZ twins (0.63; 95% CI, 0.38 to 0.89) as compared with DZ twins (0.41; 95% CI, 0.24 to 0.58). After adjusting for known risk factors, there was no evidence ( P = 0.172) for an additive genetic influence. These findings suggest that shared and unshared environmental factors, such as maternal smoking later in pregnancy and infantile eczema, are important in the etiology of HSPM.

Caries experience of children with cardiac conditions attending the Royal Children's Hospital of Melbourne.

BACKGROUND: Poor oral health in children with cardiac conditions can have negative effects on quality of life and increased risk of infective endocarditis. The aim of this study was to investigate the caries experience in children with cardiac conditions attending the Royal Children's Hospital, Melbourne. METHODS: Medical and dental records of 428 children aged <12 years were examined. Cardiac and other medical diagnoses, decayed, missing and filled surfaces/teeth were recorded and analysed. Children referred for reasons other than caries management (NRCM) was analysed separately to address confounding of referral reason on caries experience. RESULTS: Mean age of overall study population was 4.9 (SD 2.4) years, caries prevalence 52.1%, mean dmft 3.65 (SD 4.8), mean dmfs 6.19 (SD 11.3), enamel defects prevalence 29.2%. Mean age of NRCM group was 4.6 (SD 2.4) years, caries prevalence 37.5%, mean dmft 2.37 (SD 4.2), mean dmfs 4.22 (SD 9.4), enamel defects prevalence 23.0%. Untreated carious lesions accounted for 89.9% of caries experience. Caries experience was associated with low socio-economic status, absence of comorbidity and enamel defect presence. CONCLUSIONS: High disease levels were observed. Age, socio-economic status and enamel defects were associated with caries experience, not severity of cardiac diagnoses. Early referral for dental care and improved access should be facilitated.

Carious lesion severity and demarcated hypomineralized lesions of tooth enamel in schoolchildren from Melbourne, Australia.

BACKGROUND: Developmental hypomineralized lesions of enamel (DHL) may represent a significant caries-risk factor. The aim of this study was to determine the association between carious lesion severity and DHL in 6- to 12-year-old schoolchildren from Melbourne, Australia. METHODS: The sample was derived from randomly selected schools in inner Melbourne. A full dental examination was performed at the school. Socio-demographic data, caries experience (DMFT/dmft/ICDAS II) and the consequences of untreated carious lesions (PUFA/pufa) were measured. DHL, molar incisor hypomineralization (MIH) and hypomineralized second primary molar (HSPM) presence were assessed using the European Academy of Paediatric Dentistry (EAPD) criteria. RESULTS: Of the children examined (n = 327), 26.9% had DHL. The prevalence of MIH and HSPM was 14.7% and 8%, respectively. Almost 20% of children had severe carious lesions (ICDAS 5 & 6) in at least one permanent or primary tooth. Ordinal regression analyses indicated that DHL (OR = 2.17; 95% CI: 1.35-3.49) and being born overseas (OR = 2.59, 95% CI: 1.66-4.06) increased the likelihood of severe carious lesions. CONCLUSIONS: One of four children had DHL. DHL-affected children had an increased likelihood of presenting untreated severe carious lesions compared with DHL-free children.

Imaging performance of a dedicated radiation transparent RF coil on a 1.0 Tesla inline MRI-linac.

This work describes the first imaging studies on a 1.0 Tesla inline MRI-Linac using a dedicated transmit/receive RF body coil that has been designed to be completely radio transparent and provide optimum imaging performance over a large patient opening. A series of experiments was performed on the MRI-Linac to investigate the performance and imaging characteristics of a new dedicated volumetric RF coil: (1) numerical electromagnetic simulations were used to measure transmit efficiency in two patient positions; (2) image quality metrics of signal-to-noise ratio (SNR), ghosting and uniformity were assessed in a large diameter phantom with no radiation beam; (3) radiation induced effects were investigated in both the raw data (k-space) and image sequences acquired with simultaneous irradiation; (4) radiation dose was measured with and without image acquisition; (5) RF heating was studied using an MR-compatible fluoroptic thermometer and; (6) the in vivo image quality and versatility of the coil was demonstrated in normal healthy subjects for both supine and standing positions. Daily phantom measurements demonstrated excellent imaging performance with stable SNR over a period of 3 months (42.6 ± 0.9). Simultaneous irradiation produced no statistical change in image quality (p > 0.74) and no interference in raw data for a 20 × 20 cm radiation field. The coil was found to be efficient over large volumes and negligible RF heating was observed. Volunteer scans acquired in both supine and standing positions provided artefact free images with good anatomical visualisation. The first completely radio transparent RF coil for use on a 1.0 Tesla MRI-Linac has been described. There is no impact on either the imaging or dosimetry performance with a simultaneous radiation beam. The open design enables imaging and radiotherapy guidance in a variety of positons.

Xerostomia, salivary characteristics and gland volumes following intensity-modulated radiotherapy for nasopharyngeal carcinoma: a two-year follow up.

BACKGROUND: To evaluate changes in xerostomia status, salivary characteristics and gland volumes 2 years following radiotherapy in nasopharyngeal carcinoma patients. METHODS: Xerostomia scores, salivary flow rates, pH and buffering capacity were measured at pre-radiotherapy, mid-radiotherapy, 2 weeks, 3 months and 2 years post-radiotherapy. Salivary gland volumes and their correlation with radiation dose were also assessed. RESULTS: Mean radiation dose to oral cavity, parotid and submandibular glands (SMG) was 44.5, 65.0 and 38.6 Gy respectively. Parotid and SMG volumes decreased 33% at 3 months post-radiotherapy; volumes at 2 years post-radiotherapy were 84% and 51% of pre-radiotherapy levels, respectively. Correlations were observed between parotid gland volume per cent reduction and its radiation dose and between resting salivary flow rate reduction and post-radiotherapy/pre-radiotherapy SMG volume ratio. Salivary flow rates and resting saliva pH remained significantly low at 2 years post-radiotherapy (both flow rates, P = 0.001; resting saliva pH, P = 0.005). Similarly, xerostomia scores remained significantly higher compared with pre-radiotherapy levels. CONCLUSIONS: Submandibular gland volumetric shrinkage persisted 2 years after radiotherapy. Xerostomia scores remained significantly higher, and salivary flow rates and resting saliva pH remained significantly lower, suggesting that study participants were still at risk for hyposalivation-related oral diseases.

Hypomineralized second primary molars: prevalence, defect characteristics and relationship with dental caries in Melbourne preschool children.

BACKGROUND: Dental caries and enamel defects (DDE) are prevalent amongst children. The presence of DDE, especially enamel hypomineralization, may increase caries experience. The reported prevalence of hypomineralized second primary molars (HSPM) is 2.7-21.8%, although the occurrence in Australian children remains unknown. These HSPM represent a potential predictive factor for molar-incisor hypomineralization (MIH). METHODS: In total, 623 children aged 3-5 years from 30 randomly selected kindergartens participated. The HSPM were recorded using an index combining the European Academy of Paediatric Dentistry MIH Judgment Criteria and modified DDE Index. Caries was recorded using International Caries Detection and Assessment System criteria. RESULTS: In total, 144 HSPM were observed in 88 of the 623 (14.1%) children, a tooth-level prevalence of 5.8%. The prevalence of dentinal carious lesions was 13.2%, and caries prevalence (d2-6 mft > 0) was 36.4%. Cavitated carious lesions affected 30.7% of HSPM. CONCLUSIONS: The relationship between an increase in HSPM lesion extent and increasing number of HSPM per child was statistically significant. A positive association between HSPM severity and extent at tooth level existed (P < 0.05). There was a positive relationship between the extent of HSPM and carious lesion severity (P < 0.05). In this population, children with HSPM did not have overall greater caries experience.