Examining enamel-surface demineralization upon exposure to acidic solutions and the remineralization potential of milk and artificial saliva.

The enamel surface may undergo demineralization due to exposure to acidic substances and the remineralization of the etched enamel is crucial to regain or maintain integrity. This study aimed to investigate the erosive effect of 10 acidic solutions on tooth enamel and the remineralization capacity of milk and artificial saliva by measuring surface roughness (Ra), enamel depth, and microhardness. A total of 80 bovine incisor enamel specimens were immersed in 10 different acidic solutions, including four different acidic drinks, three different citric acid solutions, and three different citric acid buffer solutions, for 1 h. After demineralization, the specimens were immersed in milk and artificial saliva for 3 h. Surface roughness, enamel abraded depth, and microhardness were measured before demineralization, in-between time intervals and after remineralization. Data were analyzed using Friedman and Kruskal-Wallis tests (p < 0.05). The results indicate a significant difference in surface roughness between the measurements taken at different time intervals, particularly between the baseline and after 1 h demineralization. Also, the specimens immersed in CAB1 exhibited greatest increase in Ra among other acidic solutions (Δ: 0.18 ± 0.07). Moreover, only the microhardness increased after remineralization (p < 0.05). Enamel demineralization using various acidic solutions revealed increased Ra and enamel abraded depth, and decreased microhardness. The use of remineralization agents, milk and artificial saliva, demonstrated an increase in microhardness. This study provides insights into the effects of different acidic solutions and potential remineralization agents on tooth enamel.

Psychosocial factors, dentist-patient relationships, and oral health-related quality of life: a structural equation modelling.

BACKGROUND: Psychosocial factors and dentist-patient relationships (DPR) have been suggested to be associated with oral health outcomes. This study aimed to test a conceptual model which hypothesised relationships among psychosocial factors, DPR variables, and oral health-related quality of life (OHRQoL) in the 'distal-to-proximal' framework. METHODS: A total of 12,245 adults aged 18 years or over living in South Australia were randomly sampled for the study. Data were collected from self-complete questionnaires in 2015-2016. The outcome variable of Oral Health Impact Profile was used to measure OHRQoL. Psychosocial domain consisted of psychological well-being, social support, and health self-efficacy. DPR domain included trust in dentists, satisfaction with dental care, and dental fear. The hypothesised model was tested using the two-step approach in structural equation modelling. RESULTS: Data were analysed from 3767 respondents after the screening/preparing process (adjusted valid response rate 37.4%). In the first step of the analysis, confirmatory factor analyses produced acceptable measurement models for each of the six latent variables (GFI = 0.95, CFI = 0.98, RMSEA = 0.04). The final structural model indicated that better well-being, higher self-efficacy, and more satisfaction were associated with lower oral health impact (ß = - 0.12, - 0.07, - 0.14, respectively) whereas fear was positively associated (ß = 0.19). Among intermediates, support was positively associated with satisfaction within a small effect size (ß = 0.06) as compared to self-efficacy with trust (ß = 0.22). The invariance of the final model was also confirmed on participants' SES and dental service characteristics except the variable of 'last dental visit'. CONCLUSIONS: Psychosocial factors and DPR variables were associated with oral health impact in both direct and indirect paths. The framework of 'distal-to-proximal' actions is empirically supported from psychosocial factors via DPR variables to OHRQoL.

Adjusting the british triage system for dental care in South Korean correctional institutions: a cross-sectional study.

BACKGROUND: The oral health status of inmates in South Korean correctional institutions is poor, mainly due to limited resources and an unestablished triage system. Hence, this study aimed to develop a newly structured dental triage system for South Korean correctional institutions, using the British triage system as a reference. METHODS: This study included 32 public health dentists working at correctional institutions in South Korea in 2020, accounting for the entire population of public health dentists that year. Data on the dentists' evaluation of resources and perceptions of dental service items were collected using a self-administered online survey including 19 dental service items from the British triage system to assess the level of agreement on dental triage items. All responses were recorded within 1 week of request, and a hierarchical cluster analysis was performed to develop a new dental triage system. RESULTS: The survey included 31 respondents working at 47 correctional institutions; 16, 14, and one respondent provided dental services at one, two, and three institutions, respectively. Among the correctional institutions, 2%, 74%, and 23% were the National Forensic Hospital, prisons, and detention centres, respectively. The hierarchical cluster analysis identified four adjusted dental triage categories: emergency, urgent, routine, and checkups, mainly in accordance with those in the British system, but a few items were reallocated. The new dental triage system was compared to the existing system and found to have higher specificity and sensitivity, indicating that it may be more effective at meeting the oral health needs of inmates in South Korean correctional institutions. CONCLUSIONS: This study developed a newly structured dental triage system by adjusting the British system and evaluated its efficacy compared to the existing system. The new system may help improve the oral health status of inmates in South Korean correctional institutions by providing a more organized approach to dental care provision.

Dentists' attitudes toward patient-centered care and its predictors: a cross-sectional study in South Korea.

BACKGROUND: Patient-centered care (PCC) has been one of medical practice's most frequently discussed principles. However, attitudes toward PCC among dentists remain underexplored. This study focuses on examining dentists' patient-centered attitudes and investigating their predictors. METHODS: The Patient-Practitioner Orientation Scale which consists of Sharing and Caring subscales was used to assess patient-centered attitudes. The statistical analysis included 217 dentists from South Korea. Hierarchical linear regression analysis was performed to examine the predictors such as sociodemographic aspects, academic factors, work-related factors, and empathy. RESULTS: A patient-centered attitude of Caring subscale (M = 4.29, SD = 0.56) emerged, but the provider-centered attitude was higher in Sharing subscale (M = 3.40, SD = 0.48). Work year, academic track, and empathy were associated significantly with an overall caring aspect of patient-centered attitude, while the gender effect remained insignificant. Empathy had a critical and significant impact on the patient-centered attitude. CONCLUSIONS: Efforts to enhance patient-centeredness in Sharing are needed; post-graduate education and transition to a more patient-centered health system are recommended. Moreover, empathy still matters as it was found to be a significant predictor of patient-centered attitudes. The findings of this study support the need for efforts to enhance patient-centered attitudes among dentists, which will help generate discussion on improving the curriculum of post-graduate education and health system reform.

Human Milk Oligosaccharide 2'-Fucosyllactose Induces Neuroprotection from Intracerebral Hemorrhage Stroke.

Intracerebral hemorrhage (ICH) occurs when brain blood vessels rupture, causing inflammation and cell death. 2-Fucosyllactose (2FL), a human milk oligosaccharide, has potent antiapoptotic and anti-inflammatory effects. The purpose of this study was to examine the protective effect of 2FL in cellular and rodent models of ICH. Hemin was added to a primary rat cortical neuronal and BV2 microglia coculture to simulate ICH in vitro. IBA1 and MAP2 immunoreactivities were used to determine inflammation and neuronal survival. Hemin significantly increased IBA1, while it reduced MAP2 immunoreactivity. 2FL significantly antagonized both responses. The protective effect of 2FL was next examined in a rat ICH model. Intracerebral administration of type VII collagenase reduced open-field locomotor activity. Early post-treatment with 2FL significantly improved locomotor activity. Brain tissues were collected for immunohistochemistry and qRT-PCR analysis. 2FL reduced IBA1 and CD4 immunoreactivity in the lesioned striatum. 2FL downregulated the expression of ER stress markers (PERK and CHOP), while it upregulated M2 macrophage markers (CD206 and TGFß) in the lesioned brain. Taken together, our data support that 2FL has a neuroprotective effect against ICH through the inhibition of neuroinflammation and ER stress. 2FL may have clinical implications for the treatment of ICH.

Trust in dentist-patient relationships: mapping the relevant concepts.

Trust has a central role in healthcare encounters. This review explored concepts relevant to trust in dentist-patient relationships. The findings were demonstrated by drawing visual system maps for better understanding of the inherent complexity. A pragmatic approach was employed to search for evidence. The approach was initiated with a systematised searching protocol and followed by an iterative process of drawing maps and complementing references. The analysis-synthesis process found relevant key concepts and sub-concepts presented within three frameworks: the continuum of studying trust (utilisation, measurement, and establishment); beneficiaries of trust utilisation (patients, dentists, and oral health system); and a transformational model of trust development (identification-based, knowledge-based, and deterrence/calculus-based trust). Trust in dentist-patient relationships needs to be assessed in a multidisciplinary approach for interconnectedness among relevant concepts. The findings are represented in patient-centred care and quality of care with common underlying values. Despite the centrality of trust in medical/dental contexts, empirical evidence is insufficient beyond normative suggestions from previous studies. Based on the implications of thematic analysis and interpretation of the system maps, this paper can serve as a guide and source of information for further research of trust in dentist-patient relationships.

Determinants of Dentist-Patient Relationships: A Scoping Review.

OBJECTIVES: The dentist-patient relationship (DPR) is considered to be a key element in dental clinical settings. This scoping review aimed to examine the extent of previous research on DPR, focussing on its determinants for the reification of the construct. METHODS: This research was directed by the guidance for systematic scoping reviews from the Joanna Briggs Institute. The inclusion/exclusion criteria were based on participants of general adults and dentists, the concept of determinants of DPR, and the context of dental health care encounters. A literature search was performed in 6 major electronic databases in July 2023. Key information from included articles was extracted to chart the results, mainly to identify the determinants of DPR. Each determinant of DPR was classified according to the conceptual model of DPR. RESULTS: A total of 1727 records were initially identified, and 16 articles were included in the review. Nine studies used a quantitative method and 7 were nonempirical articles. All but 2 articles were from the perspective of patients. Factors were grouped into 6 main domains: dentist, patient, society/environment, clinical structure, clinical process, and outcome. Amongst the 6 domains of DPR, most determining factors were related to the clinical process. "Communication" was most frequently counted, at 8 times, followed by "trust" (frequency, 6). At the patient level, "dental fear/anxiety" was frequently used to measure DPR. CONCLUSIONS: Previous literature about DPR indicated a few common and dentistry-specific determinants from the patient perspective. Further studies are encouraged to develop a more comprehensive framework and evaluation scale of DPR.

De novo biosynthesis of 2'-fucosyllactose by bioengineered Corynebacterium glutamicum.

2'-Fucosyllactose (2'-FL) which is well-known human milk oligosaccharide was biotechnologically synthesized using engineered Corynebacterium glutamicum, a GRAS microbial workhorse. By construction of the complete de novo pathway for GDP-L-fucose supply and heterologous expression of Escherichia coli lactose permease and Helicobacter pylori α-1,2-fucosyltransferase, bioengineered C. glutamicum BCGW_TL successfully biosynthesized 0.25 g L-1 2'-FL from glucose. The additional genetic perturbations including the expression of a putative 2'-FL exporter and disruption of the chromosomal pfkA gene allowed C. glutamicum BCGW_cTTLEΔP to produce 2.5 g L-1 2'-FL batchwise. Finally, optimized fed-batch cultivation of the BCGW_cTTLEΔP using glucose, fructose, and lactose resulted in 21.5 g L-1 2'-FL production with a productivity of 0.12 g L-1 •h, which were more than 3.3 times higher value relative to the batch culture of the BCGW_TL. Conclusively, it would be a groundwork to adopt C. glutamicum for biotechnological production of other food additives including human milk oligosaccharides.

Cellular aging is associated with increased ubiquitylation of histone H2B in yeast telomeric heterochromatin.

Epigenetic changes in chromatin state are associated with aging. Notably, two histone modifications have recently been implicated in lifespan regulation, namely acetylation at H4 lysine 16 in yeast and methylation at H3 lysine 4 (H3K4) in nematodes. However, less is known about other histone modifications. Here, we report that cellular aging is associated with increased ubiquitylation of histone H2B in yeast telomeric heterochromatin. An increase in ubiquitylation at histone H2B lysine 123 and methylations at both H3K4 and H3 lysine 79 (H3K79) was observed at the telomere-proximal regions of replicatively aged cells, coincident with decreased Sir2 abundance. Moreover, deficiencies in the H2B ubiquitylase complex Rad6/Bre1 as well as the deubiquitylase Ubp10 reduced the lifespan by altering both H3K4 and H3K79 methylation and Sir2 recruitment. Thus, these results show that low levels of H2B ubiquitylation are a prerequisite for a normal lifespan and the trans-tail regulation of histone modifications regulates age-associated Sir2 recruitment through telomeric silencing.

Dental service sector and patient-reported oral health outcomes: Modification by trust in dentists.

Objective: The study aimed to examine the association between patient-reported oral health outcomes and the dental service sector and trust in dentists. The possible interaction effect of trust on this association was also explored. Methods: Randomly selected adults aged over 18 years living in South Australia were surveyed using self-administered questionnaires. The outcome variables were self-rated dental health and the evaluation outcome of the Oral Health Impact Profile. The dental service sector and the Dentist Trust Scale were included in bivariate and adjusted analyses with sociodemographic covariates. Results: Data from 4,027 respondents were analyzed. Unadjusted analysis showed that poor dental health and oral health impact were associated with sociodemographic characteristics, including lower income/education, public dental service, and lower trust in dentists (p < 0.01). Adjusted associations were similarly maintained (p < 0.05) but attenuated with the loss of statistical significance, mainly in the trust tertiles. Lower trust in dentists in the private sector had an interaction effect, with a higher prevalence ratio of oral health impact (prevalence ratio = 1.51; 95% confidence interval, 1.06-2.14; p < 0.05). Conclusion: Patient-reported oral health outcomes were associated with sociodemographic characteristics, the dental service sector, and trust in dentists. Implications for public health: The inequality of oral health outcomes between dental service sectors needs to be addressed both independently and in association with covariates including socioeconomic disadvantage.

2'-Fucosyllactose and 3-Fucosyllactose Alleviates Interleukin-6-Induced Barrier Dysfunction and Dextran Sodium Sulfate-Induced Colitis by Improving Intestinal Barrier Function and Modulating the Intestinal Microbiome.

Ulcerative colitis is an inflammatory bowel disease (IBD) with relapsing and remitting patterns, and it is caused by varied factors, such as the intestinal inflammation extent and duration. We examined the preventative effects of human milk oligosaccharides (HMOs) on epithelial barrier integrity and intestinal inflammation in an interleukin (IL)-6-induced cell model and dextran sodium sulfate (DSS)-induced acute mouse colitis model. HMOs including 2'-fucosyllactose (FL) and 3-FL and positive controls including fructooligosaccharide (FOS) and 5-acetylsalicylic acid (5-ASA) were orally administrated once per day to C57BL/6J mice with colitis induced by 5% DSS in the administered drinking water. 2'-FL and 3-FL did not affect the cell viability in Caco-2 cells. Meanwhile, these agents reversed IL-6-reduced intestinal barrier function in Caco-2 cells. Furthermore, 2'-FL and 3-FL reversed the body weight loss and the remarkably short colon lengths in DSS-induced acute colitis mice. Moreover, 2'-FL and 3-FL obviously protected the decreasing expression of zonula occluden-1 and occludin in colon tissue relative to the findings in the DSS-treated control group. 2'-FL and 3-FL significantly reduced IL-6 and tumor necrosis factor-α levels in serum relative to the control findings. The summary of these results shows that HMOs prevent colitis mainly by enhancing intestinal barrier function and advancing anti-inflammatory responses. Therefore, HMOs might suppress inflammatory responses and represent candidate treatments for IBD that protect intestinal integrity.

Anti-Neuroinflammatory Effects of the Human Milk Oligosaccharide, 2'-Fucosyllactose, Exerted via Modulation of M2 Microglial Activation in a Mouse Model of Ischemia-Reperfusion Injury.

Cerebral ischemic stroke is one of the leading causes of death and disability worldwide. 2'-fucosyllactose (2'-FL), a human milk oligosaccharide, exerts anti-inflammatory effects and plays a protective role in arterial thrombosis; however, its role in ischemic stroke remains unclear. This study aimed to investigate the neuroprotective effects of 2'-FL and its potential mechanisms in a mouse model of ischemic stroke. Neurological score and behavior tests revealed that 2'-FL promoted the recovery of neurological deficits and motor function in middle cerebral artery occlusion (MCAO) mice, and that 2'FL led to a reduction in the size of cerebral infarct. Biochemical studies showed that administration of 2'-FL led to a reduction of reactive oxygen species (ROS)-related products in the brain of MCAO mice. 2'-FL upregulated IL-10 and downregulated TNF-α level. In addition, 2'-FL enhanced M2-type microglial polarization and upregulated CD206 expression at 7 days after MCAO. At 3 days after MCAO, 2'-FL increased IL-4 levels and activated STAT6. Our data show that 2'-FL reduced the neurological symptoms of ischemic stroke and ROS accumulation in the brain through IL-4/STAT6-dependent M2-type microglial polarization in MCAO mice. These results demonstrate that 2'-FL is a potentially effective therapeutic agent for ischemic stroke.

The analysis of 2'-fucosyllactose concentration in Korean maternal milk using LC-MS/MS.

Despite health benefits reported recently, 2'-fucosyllactose (2'-FL) concentration in maternal milk was not conclusively reported because it varies between countries and mothers. Particularly, its distribution among Korean mothers was not obtained from a reliable sample group yet. Thus, a dynamic range for 2'-FL concentration in Korean mothers' milk was investigated from 102 samples. A quantitative method using multiple reaction monitoring (MRM) by triple-quadrupole-mass spectrometry has been evaluated by a standard procedure of method validation. The 2'-FL concentration was in the range of 0.4 to 2.6 g/L overall. While the samples from secretor mothers (n = 80) contained 1.0 to 2.8 g/L of 2'-FL, the maternal milk from non-secretor mothers (n = 22) had 0.01 to 0.06 g/L of 2'-FL only. In addition to the genetic variation of mothers, the lactation period impacted the 2'-FL concentration. The average 2'-FL concentration of the late-stage group (> 60 days) was 78% of that obtained from the first month of postpartum mothers. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01154-4.

A Bre1-associated protein, large 1 (Lge1), promotes H2B ubiquitylation during the early stages of transcription elongation.

Transcription activation has been proposed to require both ubiquitylation and deubiquitylation of histone H2B. Here, we show that Lge1 (Large 1) is found in a complex containing Rad6.Bre1 and that it controls the recruitment of Bre1, a ubiquitin ligase, and Ubp8, a deubiquitylase, to promote ubiquitylation during the early steps in elongation. Chromatin immunoprecipitation experiments showed that Lge1 associates with promoter and coding regions of actively transcribed genes in a transcription-dependent manner. Disruption of Lge1 abolished ubiquitylation of histone H2B on lysine 123 and H3 methylation on lysines 4 and 79 and resulted in significant sensitivity to 6-azauracil and mycophenolic acid. In particular, in Lge1-deficient cells, Bre1 recruitment was attenuated, whereas recruitment of Ubp8 was facilitated. These alterations were coincident with changes in the interaction between Bre1.Ubp8 and RNA polymerase II phosphorylated at serine 5 of the C-terminal domain. We propose that Lge1 has a novel function in disrupting the balance between the recruitment of Bre1 and Ubp8, thus promoting transcription elongation.

Community Water Fluoridation: Caveats to Implement Justice in Public Oral Health.

Community water fluoridation (CWF), a long-established public health intervention, has been studied for scientific evidence from both of yea and nay standpoints. To justify CWF with scientific evidence inevitably leads to ethical justification, which raises the question of whether oral health is of individual concern or social responsibility. As dental caries is a public health problem, public health ethics should be applied to the topic instead of generic clinical ethics. From both pro- and anti-fluoridationists' perspectives, CWF is a public health policy requiring a significant level of intervention. Thus, there needs to take further considerations for justifying CWF beyond the simple aspect of utility. For further ethical considerations on CWF, three caveats were suggested: procedural justice, social contexts, and maintenance of trust. The process to justify CWF should also be justified, not simply by majority rule but participatory decision-making with transparency and pluralistic democracy. Social contexts are to be part of the process of resolving conflicting values in public health interventions. Public trust in the dental profession and the oral healthcare system should be maintained over the considerations. This article suggests accountability for reasonableness as a framework to consider infringement by CWF for public justification of its implementation.

Association of periodontitis with oral malodor in Korean adults.

This study aimed to evaluate the association of periodontitis with the organoleptic score (OLS)-defined oral malodor after validating OLS with odoriferous sulfur compounds in mouth air among Korean adults. A total of 330 adults aged 47-86 years were recruited from the Yangpyeong health cohort, South Korea, in 2015. Oral malodor was assessed using a 6-point OLS by a trained dentist and validated with the concentrations of hydrogen sulfide (HS) and methyl mercaptan (MM) using a gas chromatographer. Periodontitis was measured by assessing the radiographic alveolar bone loss on digital orthopantomography. Statistical analyses including descriptive statistics, partial correlation, ANOVA, and multivariable logistic regression with putative confounders were applied. OLS was significantly correlated with the concentrations of HS and MM (partial r = 0.401 and 0.392, respectively; both p<0.001) after controlling for confounders. Individuals with periodontitis had 1.8 times the risk of OLS-defined oral malodor in multivariable models (adjusted odds ratio = 1.77 in the model with the number of teeth and 1.82 in the model with denture wearing; p = 0.047 and 0.035, respectively). Periodontitis was associated with OLS-defined oral malodor among Korean adults independent of known confounders. Periodontal conditions should be considered for clinical practice and research of oral malodor.

Physicochemical characteristics of SAPO-34 molecular sieves synthesized with mixed templates as MTO catalysts.

In the present work, a variety of SAPO-34 catalysts have been prepared using various templates such as a single or mixtures of tetraethylammonium hydroxide (TEAOH), morpholine, diethylamine (DEA), triethylamine (TEA), dipropylamine (DPA), isopropylamine (IPA) and Diethanolamine (DEtA). It is shown that crystal morphology and physicochemical properties were affected by the kinds of templates and mixture contents. Especially, inexpensive SAPO-34 catalyst with good crystal properties and catalytic performance was obtained by using mixed template of DEA and TEAOH. Through N2 isotherm, XRD, SEM, NH3 TPD and 29Si-NMR techniques, the effect of mixed template on the crystal morphology, acidity and Si distribution were investigated. Catalytic activity and life stability of SAPO-34 in MTO reaction was improved by using mixed template because of the distinction of the crystal size, acidity and Si distribution.

Dentist-patient relationships and oral health impact in Australian adults.

OBJECTIVES: Dentist-patient relationships (DPRs) are a key component in clinical encounters with potential benefits for oral health outcomes. This study aimed to investigate whether better DPR variables are associated with higher oral health-related quality of life (OHRQoL). METHODS: A total of 12 245 adults aged 18 years or over were randomly sampled from South Australia in 2015-2016. Data were collected from self-complete questionnaires and analysed as a cross-sectional design. The outcome variable was the Oral Health Impact Profile (OHIP-14). Explanatory DPR variables included trust in dentists, satisfaction with dental care, and dental fear. Covariates comprising oral health behaviours, dental services, demographics, and socioeconomic status were included as potential confounding variables. Bivariate correlation analyses and multivariable linear regression were performed for the associations among explanatory, outcome variables and other covariates. RESULTS: Response data were analysed from 4220 participants (response rate = 41.9%). Unadjusted mean total scores of DPR variables and OHIP-14 were associated with most of the study participants' characteristics (P < .05). Bivariate correlations among DPR variables and OHIP-14 showed a diverse range of coefficients (|r| or |ρ|=0.22-0.67). Multivariable regression analyses in both individual/clustered block entry and full model indicated that higher satisfaction and less dental fear (B = -0.039 and 0.316, respectively in the full model) were associated with lower OHIP-14 after adjusting for possible confounders (P < .01). CONCLUSIONS: This study found that favourable DPR variables, mainly greater satisfaction and less dental fear are positively associated with better OHRQoL. Further studies are warranted to investigate the causality and mediation/moderation of DPR variables on oral health outcomes.

Are trust and satisfaction similar in dental care settings?

OBJECTIVES: Trust and satisfaction in dental care settings are salient constructs to operationalize the concept of dentist-patient relationships (DPR). This study aimed to compare the similarity of both constructs with regard to factor structure and revise the scales for better psychometric properties. METHODS: Data analysed in the study were collected in self-complete questionnaires from a random sample of 4011 adults living in South Australia. Trust and satisfaction were assessed using the Dentist Trust Scale and the Dental Care Satisfaction scale. Items in the scales were initially examined with a split-half sample in exploratory factor analysis and cluster analysis. Factor structures of different model designs were tested on the other half sample in confirmatory factor analysis. The final model was cross-validated on the first half sample for structural invariance. RESULTS: Exploratory factor analysis revealed a three-factor structure consisting of 'trust', 'satisfaction' and 'distrust/dissatisfaction' (60.2% of the variance explained; Cronbach's α = 0.94, 0.81, 0.73, respectively). Cluster analysis supported the factor solution with the same three major clusters except for a single-item independent branch of the 'cost' domain from the satisfaction scale. The final model was designed with two correlated but distinct factors, 'trust' and 'satisfaction', with the modification of one inter-item covariance and deleting the least associated item (GFI = 0.96, CFI = 0.98, RMSEA = 0.06). The stability of the final model was achieved through cross-validation (P = .143, ∆CFI < 0.001). CONCLUSIONS: Trust and satisfaction in dental care settings are unidimensionally different yet highly correlated factors concurrently. Demonstrating the discriminant and complementary functions of both constructs can justify the rationale to apply them together in further studies for DPR.

Degrees of xerostomia? A Rasch analysis of the Xerostomia Inventory.

OBJECTIVE(S): The global demographic changes resulting in an ageing population require attention on xerostomia, as its prevalence appears to increase with age. The Xerostomia Inventory (XI) is a 11-item instrument developed to evaluate the symptoms and behavioural components of xerostomia, while a shortened 5-item version named Summated Xerostomia Inventory (SXI) was later proposed. The aim of the present study was to evaluate the construct validity of the XI and whether the SXI can provide a shortened version. Since previous studies focused only on dimensionality and reliability, we employed modern psychometric methodology to investigate properties such as differential item functioning (DIF) and targeting. STUDY DESIGN: The XI was applied to 164 middle-aged to older adults who participated in a randomized controlled trial to investigate the effects of alcohol-containing mouth rinse in Singapore. The psychometric properties of the XI were investigated with the Rasch model (Partial Credit Model). Overall model fit was evaluated with a summary chi-square statistic. Item fit was evaluated with the Fit Residual, and values between -2.5 and 2.5 are considered acceptable. DIF by sex was evaluated through a two-way ANOVA of the residuals. RESULTS: After collapsing the categories of "Hardly ever" and "Fairly often", the test of global fit (χ2 (30) = 34.32, P = .27) indicated overall fit to the Rasch model. Since Fit Residuals were between -2 and 2, the fit of individual items was also adequate. No DIF was found between men and women, and targeting was adequate (µ = -0.56). CONCLUSION: The current study expanded the evidence on the XI and SXI validity and provides new implications for practice: a 3-point categorization ("Never," "Occasionally" and "Very often") should be preferred rather than the original 5-point categorization; the XI and SXI scores can be compared between men and women and will reflect true differences in xerostomia rather than measurement bias.