Red-fluorescing dentine indicates bacterial contamination [Lennon et al.: Caries Res 2002;36:315-319]. We investigated effect of removal of red-fluorescent dentine-caries on shear-bond-strength and fracture-mode of 4 adhesive approaches. Sixty-five carious teeth and 50 non-carious controls were distributed into 4 groups: ClearfilTM self-etch (CSE), OptibondTM FL total-etch (OTE), ScotchbondTM Universal total-etch (STE) and self-etch (SSE). Samples were excited at 405nm and viewed through 530nm filter. Carious samples were ground flat exposing strongly red-fluorescing-dentine (StrongRF), on which a composite-cylinder was placed, using one of 4 adhesives. After 22 hours in water shear-bond-strength and fracture-mode were analysed. StrongRF was removed composite-cylinders were placed on weakly-red-fluorescing dentine (WeakRF) and tested as described above. Finally, red-fluorescing dentine was removed, composite-cylinders were placed on non-fluorescing dentine (NonRF) and tested. Composites were placed at 3 corresponding heights in controls. After 22 hours in water, shear-bond-strength testing and fracture-mode analysis were performed. Differences were tested using Mann-Whitney or Wilcoxon tests (p≤0.05). Median(Q1,Q3) shear-bond-strength on StrongRF was: SSE 14.4(9.2, 18.2)MPa >CSE 10.2(6.4, 17.3)MPa >STE 9.1(6.9, 11.2)MPa >OTE 6.8(4.0, 10.8)MPa. Shear-bond-strength increased statistically significantly for all adhesives on WeakRF (p<0.001-p=0.013): SSE 19.8(13.6, 24.3)Mpa >STE 19.5(12.7, 23.1)MPa >CSE 17.5(12.0, 22.5)MPa >OTE 15.8(11.9,20.9)MPa. Only STE 25.6(22.4,29.1)MPa and CSE 22.1(17.6,24.6)MPa were significantly different on NonRF compared to WeakRF. For controls tested at corresponding depths, superficial shear-bond-strength was: OTE 18.7(16.0,22.1)MPa >STE 18.4(12.0,25.9)MPa >CSE 18.1(12.7,20.7)MPa >SSE 13.0(9.6,17.8)MPa. This was significantly higher compared to StrongRF except for SSE. Central shear-bond-strength was not significantly different to WeakRF, deep shear-bond-strength was significantly lower for SSE and CSE but higher for OTE compared to carious. Conclusion: strongly red-fluorescing dentine should be removed for higher shear bond strength, but weakly red-fluorescing dentine can be preserved without compromising adhesive bond strength.

A highly cited paper is a milestone and might impact research and clinical practice. The present study analyzed the 100 most-cited papers on fluoride varnishes in dentistry. A search was performed on July 20, 2022, on the Web of Science Core Collection. Two independent researchers extracted the following data: number and citation density; year and journal of publication; study design; main topic; authors; institutions; keywords; countries and continents. Scopus and Google Scholar were consulted to compare the number of citations. Bibliometric networks were generated in the VOSviewer. The number of citations ranged from 36 to 351, and thirteen papers were cited more than 100 times. The papers were published between 1977 and 2018, most of which were published after 2008 (48%). The most prevalent journal was Caries Research (17%). Intervention studies were the most common design (41%). The most discussed topics were dental caries prevention (48%) and dental remineralization (31%). Europe was the continent with the highest number of publications (46%), mainly from Sweden (14%), and Umea University had the most substantial number of studies (8%). Petersson LG was the author with more papers in the top 100 (6%). The most used keywords were "dental caries" (34%) and "fluoride varnish" (31%). It can be concluded that the top 100 cited papers on fluoride varnish primarily originated from Europe, with the majority consisting of intervention studies focusing on the utilization of fluoride varnish for the prevention of dental caries.

Sodium hexametaphosphate (HMP) as toothpaste additive is claimed to reduce erosive tooth wear and to stabilize stannous ions. However, little is known about the impact of concentration and its interactions with fluoride (F) or stannous+fluoride ions (F/Sn) on enamel erosion and erosion-abrasion. In a ten day cyclic in-vitro erosion-abrasion model, 320 flat human enamel specimens were divided into ten groups (n = 32 each) and daily subjected to six erosive challenges (0.5% citric acid, 2 min) and two toothpaste suspension applications (2 min, 1:3 F-free toothpaste:mineral-salt-solution, 0.23% sodium-gluconate). Half of specimens per group were additionally brushed twice/day (200 g, 15 s) during suspension immersion. Nine suspensions contained HMP (0.25%, 1.75%, 3.25%), either on its own or combined with F (373 ppm F-) or F/Sn (800 ppm Sn2+, 373 ppm F-). One suspension contained sodium-gluconate only (NegContr). After ten days, specimens' surfaces were analyzed with profilometry, energy dispersive x-ray spectroscopy and scanning electron microscopy. Tissue loss (µm, mean ± standard deviation) in NegContr was 10.9 ± 2.0 (erosion), 22.2 ± 1.6 (erosion-abrasion). Under erosive conditions, only 0.25% HMP in any combination and 1.75% HMP with F/Sn reduced loss significantly (-28% to -54%); 3.25% HMP without F and F/Sn increased loss significantly (+35%). With additional abrasion no suspension reduced loss significantly compared to NegContr, instead, in groups without F and F/Sn or with 3.25% HMP loss was increased (+15% to +30%). Conclusively, at higher concentrations HMP increased erosive tooth wear and seemed to reduce anti-erosive effects of fluoride and stannous ions.

Green tea-derived catechins, which can be divided into galloylated (epicatechin gallate: ECG, epigallocatechin gallate: EGCG) and non-galloylated (catechin: C, epicatechin: EC, epigallocatechin: EGC) catechins, are considered to be the main contributors to the caries control potential of green tea. In this study, we intended to compare the antimicrobial effects of these representative green tea-derived catechins and their combined effects with fluoride on the acid production and aggregation of Streptococcus mutans. The effects of different catechins on the growth, aggregation and acid production of S. mutans, and the combined effect of catechins and potassium fluoride (KF) (2 mM at pH 7.0, 0.3 mM at pH 5.5) on S. mutans acid production were measured by anaerobic culture, turbidity changes due to aggregation, and pH-stat methods. Molecular docking simulations were also performed to investigate the interactions between catechins and membrane-embedded enzyme II complex (EIIC), a component of the phosphoenolpyruvate-dependent phosphotransferase system, sugar uptake-related enzymes. One mg/ml of ECG or EGCG significantly inhibited the growth of S. mutans, induced bacterial aggregation, and decreased glucose-induced acid production (p <0.05). All catechins were able to bind to EIIC in silico, in the following order of affinity: EGCG, ECG, EGC, EC, and C. Furthermore, they enhanced the inhibitory effects of fluoride at pH 5.5 and significantly inhibited S. mutans acid production by 47.5-86.6% (p <0.05). These results suggest that both galloylated and non-galloylated catechins exhibit antimicrobial activity, although the former type demonstrates stronger activity, and that the caries control effects of green tea may be due to the combined effects of multiple components, such as catechins and fluoride. The detailed mechanisms underlying these phenomena and the in vivo effect need to be explored further.

This study identified factors that influence dentists' decisions regarding less invasive caries removal techniques such as stepwise removal (SW) and selective removal (SE) using a marketing research technique, conjoint analysis. A survey was sent to 1,434 dentists practicing in Iowa. Dentists were randomly assigned to receive a questionnaire to rate the likelihood they would use either SW/SE in hypothetical clinical scenarios. The scenarios were carefully created by conjoint design and included three relevant attributes: depth of lesion, hardness of carious dentin and patient age. Descriptive and conjoint analysis were performed to assess trade-offs between these attributes, using SPSS Results: The study revealed that depth of lesion was the most important factor in dentists' decisions (49 importance value) when choosing a SW to treat a deep carious lesion (DCL), followed by hardness of carious dentin and patient age (21 importance value). For the SE-group, depth of the lesion was also the predominant factor when selecting a treatment. The study also identified that a high proportion of dentists (24.9%) indicated they would never consider using SW or SE under any circumstances. Our survey showed that depth of lesion was the most important reason to select a less invasive caries removal method. The high proportion of dentists indicating they would never consider selective caries removal techniques suggests that these less invasive options are underutilized.

Due to practical difficulties in quantifying fluoride exposure in populations, practical and accurate biomarkers can play a major role in the surveillance of fluoride. Among different fluoride biomarkers, spot urine and nail-clippings have gained more attention due to their ease of acquisition. However, there is no robust consensus about the accuracy of these biomarkers for the estimation of fluoride exposure. This systematic review and meta-analysis aimed to synthesize evidence on the association between fluoride exposure and the fluoride concentration of spot urine and nail-clippings. This review was conducted and reported using the PRISMA Statement. Nine databases (Medline, CINAHL, Web of Science, Scopus, ScienceDirect, Sage Journals Online, Campbell Collaboration, Cochrane Collaboration, and Embase); search engines (Google and Google Scholar); and grey literature were searched up to September 2022. All screening, data extraction, and quality assessments were conducted in duplicate. All experimental and observational research studies that reported the correlation between fluoride exposure and fluoride concentrations of spot urine and/or nail clippings were included. The Mixed-Methods Appraisal tool was used to assess the methodological quality of the included studies. A random effect meta-analysis was carried out to determine the relationship between fluoride exposure and fluoride concentration of biomarkers (i.e., spot urine and nail clippings). Forty-four studies met the inclusion criteria. A total of 694,578 participants were included in this review. Twenty-five studies were included in the meta-analysis. The primary meta-analysis showed a moderate correlation of 0.674 (95%CI: 0.623-0.725, n=25) between fluoride intake and fluoride concentration of spot urine and a strong correlation of 0.938 (95%CI: 0.520-1.355, n=11) between fluoride intake and the fluoride concentration of nail-clippings in all age groups. The findings of secondary meta-analyses showed a strong positive correlation between fluoride intake and fluoride/creatinine ratio of spot urine in children (0.929; 95%CI: 0.502-0.991; n=2). In conclusion, spot urine and nail-clippings have the potential to be employed as non-invasively obtained biomarkers in populations. However, due to the scarcity of high-quality, relevant studies, more research is needed to establish the validity of these biomarkers.

Early caries diagnosis is crucial to treatment decisions in dentistry and requires identification of lesion activity: whether a carious lesion is active (progressively demineralizing) or arrested (progressively remineralizing). This study aimed to identify microtomographic (micro-CT) differences between active and arrested smooth surface enamel lesions, to quantify those micro-CT differences by creating thresholds for ex vivo caries activity assessment to serve as a future reference standard, and to validate those thresholds against the remaining sample. Extracted human permanent teeth (n=59) were selected for sound surfaces and non-cavitated smooth surface carious lesions. Each surface was then examined for caries activity by calibrated individuals via visual-tactile examination using the International Caries Classification and Management System (ICCMS) activity criteria. Each tooth was scanned via micro-CT and the mineral density was plotted against lesion depth. The area under the curve (AUC) was calculated and represented the loss of density for the outermost 96 μm of enamel. AUC thresholds obtained from micro-CT were established to classify sound, remineralized, and demineralized surfaces against the gold standard examiner's lesion assessment of sound, inactive, and active lesions, respectively. The established AUC thresholds demonstrated moderate agreement with the assessment in identifying demineralized lesions (k=0.45), with high sensitivity (0.73) and specificity (0.77). This study demonstrated quantifiable differences among demineralized lesions, remineralized lesions, and sound surfaces, which contributes to the establishment of micro-CT as a reference standard for caries activity that may be used to improve clinical and laboratorial dental caries evaluations.

The objective was to study the long-term effects on oral health of bariatric surgery compared with medical treatment of obesity. Swedish females with morbid obesity (n = 66;18-35 years at baseline) were followed prospectively from before obesity treatment until two years after treatment. The main response variable was dental caries registered according to the ICDAS-II system. Possible confounding caused by sociodemographic characteristics, general health, oral health habits and oral hygiene was controlled for. The statistical methods included Chi-square tests, Student's t-tests, one-way ANOVA, Wilcoxon's non-parametric tests and linear regression models. In the surgically treated patients (n = 40), a significant increase over time in enamel caries (mean increase 4.13 tooth surfaces ICDAS1-2), dentine caries (mean increase 2.18 tooth surfaces ICDAS3-6), and total caries (mean increase 6.30 tooth surfaces ICDAS1-6) was registered (all p < 0.001), which was not seen in the medically treated patients (n=26). However, the difference between the treatment groups (surgical or medical) was only statistically significant for enamel caries (crude β 4.89, p=0.003) and total caries (crude β 6.53, p<0.001). The relationships were stable and independent of differences in confounders as socioeconomy, general health and oral health behaviors. In conclusion, two years after obesity treatment, a significant increase in dental caries was registered in the surgically treated but not in the medically treated women. The dental service should intensify its preventive efforts in individuals undergoing obesity treatment.

This prospective cohort study assessed the radiographic progression of underlying dentin shadows (UDS) on the occlusal surfaces of permanent posterior teeth of adolescents and young adults over 1-2 years and to identify possible risk factors. A total of 149 UDS lesions (from 101 individuals) were included at baseline. Each participant had to present at least one UDS to be considered eligible for the study. Data collection included the application of a questionnaire, clinical examination, and bilateral bitewing radiographs, performed at baseline and after 1-2 years. The association between possible predictors and UDS progression (defined radiographically as an increase in the radiographic score from baseline to follow-up) was assessed using Weibull regression models. Hazard ratios (HR) and their 95% confidence intervals (CI) were estimated. A total of 81 individuals (mean age 24.0, standard deviation 8.03) were reexamined after 1-2 years (742 occlusal surfaces, of which 118 were UDS). The overall progression rate was 8.6% after 1-2 years, being 12.6% for UDS without baseline radiolucency and 20% for UDS with baseline radiolucency. The risk analysis showed that UDS without radiolucency at baseline had a similar likelihood of progression (adjusted HR=1.71, 95%CI=0.68-4.32, p=0.26) while UDS with radiolucency at baseline were more likely to progress (adjusted HR=2.96, 95%CI=1.06-8.26, p=0.04) than the reference category (sound occlusal surfaces without radiolucency). These estimates were adjusted for caries prevalence, tooth type, and arch. This study showed low progression rates of UDS after 1-2 years. The presence of radiolucency at baseline was found to predict UDS progression.

The aim of this study was to determine the immediate and sustained effect of a fluoride varnish and its combinations with toothpastes in preventing root caries development using a salivary microcosm in vitro model. Human root dentin specimens (n=150) were randomly divided into 5 experimental protocols (n=30): (1) Fluoride Varnish (V); (2) V followed by Paste One (V+PO); (3) V followed by Paste Plus (V+PP); (4) V followed by PO and PP (V+PO+PP); and (5) No treatment (control). One varnish layer was applied on the specimens (except for the control group) and kept for 18 h. Then, the varnish was removed and toothpastes treatments were initiated accordingly to experimental groups. For the short-term incubation model (n=15), the specimens were also immediately subjected to 7-day cariogenic challenge. For that, human saliva was used as bacterial inoculum and Mc Bain artificial saliva containing 2% sucrose as growth medium. The other half of the specimens (n=15) was used to study the varnish's sustained effect by long-term incubation (8 weeks) before cariogenic challenge. The protocols' anti-caries properties were evaluated by dentin porosity (Rhodamine intensity; RI) and mineral density while their anti-biofilm effects were evaluated using biofilm's biomass and viability assays. For short- and long-term incubation models, all experimental regimens resulted in statistically significant decreases (p<0.05) in the RI (up to 180 µm and 120 µm, respectively) as well as higher mineral density compared to No treatment (p<0.001). V+PO+PP and/or V+PO resulted in statistically lower RI compared to V for some depths (p<0.05) in both models. There were changes in RI and mineral density within groups overtime. All experimental treatments exhibited anti-biofilm effects. All prevention protocols exhibited immediate and sustained anti-caries effect against root caries development. The combination of a fluoride varnish with PO resulted in superior additional anti-caries effects.