Frontiers of Global Research Trend on Root Caries: A Bibliometric Analysis

OBJECTIVE

This study aimed to examine the global research trend and frontiers in the field of root caries.

METHODS

Two independent investigators searched the Web of Science Core Collection to include journal articles published on root caries from 1994 to 2023. They examined citation trends of the selected publications and performed bibliometric analysis using VOSviewer. Cooccurrence and cocitation analysis were used to calculate the burst strength of the most cited keywords and the most cited publications.

RESULTS

This study included 1144 publications (1004 scientific research articles and 140 review articles) for bibliometric analysis. The number of publications from 2018 to 2023 was 404, accounting for 35% (404/1144) over the last 30 years. The annual citation count showed a gradual upward trend with a surge from 2018. The cooccurrence analysis classified the publications into four clusters which were in vitro studies, prevention, microbiology, and epidemiology. Cocitation analysis revealed silver diamine fluoride, systematic review, and randomized clinical trial were the three main keywords; and their citation burst strength (period) were 17.2 (2017-2023), 9.4 (2015-2023), and 6.9 (2018-2023), respectively. Noninvasive treatment of root caries (narrative review), aetiology of root caries (narrative review), and use of silver diamine fluoride in arresting root caries (clinical trial) were the topics (publication type) of the three most cited publications; and their burst strength (period) were 8.9 (2017-2020), 5.9 (2017-2021), and 4.7 (2015-2018), respectively.

CONCLUSION

This study highlights the recent growing research interest in root caries, particularly on its microbiology, prevention, and the use of silver diamine fluoride.

Immediate and sustained root caries prevention of fluoride varnish combined with toothpastes: findings of clinical relevance?

DESIGN

An in vitro study to determine the immediate and sustained effect of fluoride varnish and its combination with fluoride toothpastes in preventing the development of root caries.

CASE SELECTION

Human root dentine samples (150) were randomly divided into five experimental protocols of 30 specimens each: 1) fluoride varnish (22,600 ppm fluoride and 1-5% CPP-ACP); 2) fluoride varnish followed by Paste One (1100 ppm sodium fluoride and CPP-ACP); 3) fluoride varnish followed by Paste Plus (900 ppm sodium fluoride and CPP-ACP); 4) fluoride varnish followed by Paste One and Paste Plus; and 5) no treatment (control). A layer of varnish was applied to specimens except the control group and was left in situ for 18 h. The varnish layer was removed, and the various toothpaste treatments were initiated. Half of the specimens in each group were assigned to a short-term incubation model in which they were immediately subjected to a 7-day cariogenic challenge consisting of a combination of human saliva and artificial saliva containing 2% sucrose. The other half of the specimens in each group were assigned to the long-term incubation model in which the experimental protocol was continued for 8 weeks before initiating the seven-day cariogenic challenge. The protocols were evaluated by assessing dentine porosity (rhodamine intensity), mineral density, biofilm biomass, and viability assays.

DATA ANALYSIS

Confocal laser scanning microscopy was used to determine dentine porosity and Levene's test was used to verify the assumption of equality of variances and normal distribution of errors before two-way ANOVA and the Games-Howell test were carried out at a significance level of 0.05 for both incubation models. Microcomputed tomography was used to determine mineral density with statistical analysis involving Levene's test, two-way ANOVA and Tukey's test at a significance level of 0.05 for both incubation models. Biomass was evaluated using a biofilm biomass assay with analysis of optical density data using Levene's test, ANOVA and Scheffe's test at a significance level of 0.05.

RESULTS

For both the short- and long-term incubation models, all the experimental regimes resulted in a statistically significant decrease in dentine porosity and an increase in mineral density when compared to the control group. Fluoride varnish followed by both pastes and fluoride varnish followed by Paste One resulted in a statistically significant decrease in dentine porosity for some depths in both models when compared to fluoride varnish alone. Changes in dentine porosity and mineral density were observed within groups over time. All the experimental regimes demonstrated anti-biofilm effects. Immediate and sustained anti-caries effects were observed for all preventive protocols, with the combination of fluoride varnish and Paste One resulting in superior additional anti-caries effects.

CONCLUSIONS

The authors concluded that all protocols demonstrated immediate and sustained anti-caries effects against the development of root caries despite variations in effects over time. The combination of fluoride varnish and Paste One resulted in additional anti-caries effects that were consistently superior, with no additional effects being observed when Paste Plus was added in combination. The authors suggest that, within the study's limitations, topical fluoride varnish seems to have a protective effect on root surfaces for up to eight weeks and that fluoride varnish should be considered as an important adjunct strategy in the prevention of root caries in older adults.

Riboflavin Attenuates Fluoride-Induced Testicular Injury via Interleukin 17A-Mediated Classical Pyroptosis

Male reproductive toxicity of fluoride is of great concern worldwide, yet the underlying mechanism is unclear. Pyroptosis is a novel mode of inflammatory cell death, and riboflavin with anti-inflammatory properties has the potential to protect against fluoride damage. However, it is unknown whether pyroptosis is involved in fluoride-induced testicular injury and riboflavin intervention. Here, we first found that riboflavin could alleviate fluoride-caused lower sperm quality and damaged testicular morphology by reducing pyroptosis based on a model of ICR mice treated with NaF (100 mg/L) and/or riboflavin supplementation (40 mg/L) via drinking water for 13 weeks. And then, together with the results of in vitro Leydig cell modelsm it was confirmed that the pyroptosis occurs predominantly through classical NLRP3/Caspase-1/GSDMD pathway. Furthermore, our results reveal that interleukin-17A mediates the process of pyroptosis in testes induced by fluoride and riboflavin attenuation according to the results of our established models of riboflavin- and/or fluoride-treated IL-17A knockout mice. The results not only declare a new mechanism by which fluoride induces testicular injury via interleukin 17A-mediated classical pyroptosis but also provide evidence for the potential clinical application of riboflavin as an effective therapy for fluoride toxicity.

Changes in Gloss Alteration, Surface Roughness, and Color of Direct Dental Restorative Materials after Professional Dental Prophylaxis

In the context of optimizing dental care for patients who are elderly, the purpose of this in vitro study was to evaluate the surface gloss (with a micro-area gloss meter) of, surface roughness (with a compact surface roughness measuring instrument) of, and color change (with a dental colorimeter) in two commercially available injectable resin-based composites (Estelite Universal Flow (EUF) and Beautifil Flow Plus F00 (BFP)) as well as two glass-ionomer cements (GC Fuji II LC CAPSULE (FLC) and GC Fuji IX GP EXTRA CAPSULE (FGP)), before and after dental prophylaxis. After 24 h, the surfaces of each specimen were polished at 2500 rpm with a prophy brush (Mersage Brush, Shofu) and one-step prophylaxis paste (Prophy Paste Pro, Directa): under 100 or 300 gf load, and for 10 or 30 s, 4× cycles of cleaning. After mechanical cleaning, conditions were found for a significant reduction in the gloss level (EUF, BFP, or FLC; p < 0.05) and a significant increase in surface roughness (BFP; 300 gf load, 10 s × four cycles of cleaning). Overall, the longer time or higher prophylaxis load tended to decrease the surface gloss. However, the observed change in surface roughness varied between the restorative materials. There was no color change post-prophylaxis.

How do network meta-analyses address intransitivity when assessing certainty of evidence: a systematic survey

OBJECTIVES

To describe how systematic reviews with network meta-analyses (NMAs) that used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) NMA approach addressed intransitivity when assessing certainty of evidence.

DESIGN

Systematic survey.

DATA SOURCES

Medline, Embase and Cochrane Database of Systematic Reviews from September 2014 to October 2022.

ELIGIBILITY CRITERIA

Systematic reviews of randomised controlled trials with aggregate data NMAs that used the GRADE NMA approach for assessing certainty of evidence.

DATA EXTRACTION AND SYNTHESIS

We documented how reviewers described methods for addressing intransitivity when assessing certainty of evidence, how often they rated down for intransitivity and their explanations for rating down.

RESULTS

Of the 268 eligible systematic reviews, 44.8% (120/268) mentioned intransitivity when describing methods for assessing the certainty of evidence. Of these, 28.3% (34/120) considered effect modifiers and from this subset, 67.6% (23/34) specified the effect modifiers; however, no systematic review noted how they chose the effect modifiers. 15.0% (18/120) mentioned looking for differences between the direct comparisons that inform the indirect estimate. No review specified a threshold for difference in effect modifiers between the direct comparisons that would lead to rating down for intransitivity. Reviewers noted rating down indirect evidence for intransitivity in 33.1% of systematic reviews, and noted intransitivity for network estimates in 23.0% of reviews. Authors provided an explanation for rating down for intransitivity in 59.6% (31/52) of the cases in which they rated down. Of the 31 in which they provided an explanation, 74.2% (23/31) noted they detected differences in effect modifiers and 67.7% (21/31) specified in what effect modifiers they detected differences.

CONCLUSIONS

A third of systematic reviews with NMAs using the GRADE approach rated down for intransitivity. Limitations in reporting of methods to address intransitivity proved considerable. Whether the problem is that reviewers neglected to address rating down for transitivity at all, or whether they did consider but not report, is not clear. At minimum systematic reviews with NMAs need to improve their reporting practices regarding intransitivity; it may well be that they need to improve their practice in transitivity assessment. How to best address intransitivity may remain unclear for many reviewers thus additional GRADE guidance providing practical instructions for addressing intransitivity may be desirable.

Immediate and Sustained Root Caries Prevention of Fluoride Varnish Combined with Toothpastes

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 toothpaste treatments were initiated according 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 McBain artificial saliva containing 2% sucrose as growth medium. The other half of the specimens (n = 15) were 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 over time. 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.

Analyzing the anti-caries effect of fluoride varnish containing tricalcium phosphate using PIXE/PIGE

This study evaluated the effect of tricalcium phosphate-containing fluoride varnish on the prevention of root caries using an in-air micro-proton induced X-ray/gamma-ray emission system and microcomputed tomography. Either fluoride varnish (FV) or tricalcium phosphate-containing fluoride varnish (WV) was applied to root dentin, whereas dentin without varnish were considered controls. After immersion in saline, dentin sections were prepared, and concentration of fluoride ion was measured. These specimens were demineralized, and the mineral loss was measured. Caries inhibition in sound and demineralized dentin was observed in both FV and WV groups compared to the control group. Significantly low mineral loss was found especially in the demineralized dentin, which is probably due to the combination effect of calcium and fluoride ions at a concentration range of 100,000 ppm, as supplied by the varnish. The use of calcium-containing fluoride varnish, especially in demineralized dentin, is effective in arresting initial dentin caries.

Dental innovations which will influence the oral health care of baby boomers

From the widespread use of smartphones and tablets to the multitude of applications available, older adults are showing an interest in utilizing technology to maintain their independence and to improve their quality of life. As technology continues to advance and be incorporated into many day-to-day activities, the baby boom generation will see these changes affecting the way they access and utilize dental services. Innovative toothbrushes and chemotherapeutics are continuing to be developed and utilized by many older adults. Within the dental office, older adults are seeing greater application of technology in every day dental procedures. These include the use of teledentistry, artificial intelligence (AI), innovative restorative materials, digitization of fixed and removable prosthodontics, cone beam computed tomography (CBCT) scans to guide dental implant placement and endodontic procedures. There is also new technology to aid in cancer detection and shielding during cancer treatment. Improved communication between the medical and dental fields has become increasingly necessary to facilitate effective patient care and a few innovative healthcare systems have begun to consolidate these services. Overall, the baby boom generation will continue to see dental innovations that will change the way they experience everyday life and dental services.

A Review on Experimentally Proven Medicinal Plants and Their Constituents against Fluoride Toxicity

Fluoride toxicity, principally by polluted groundwater, is regarded as a momentous global public health risk, as there is no particular and proven treatment for chronic fluoride toxicity i.e., fluorosis which leads to several serious health complications. Scientific literature reveals several medicinal plants and natural products alleviate experimentally induced fluoride toxicity. The present review attempts to collate those experimental studies on medicinal plants and plant derived natural products with fluoride toxicity ameliorative effects. Literature scrutiny was performed by using online bibliographic databases and the studies for the last 15 years were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded. Literature study revealed that 25 medicinal plants and 17 natural products exhibited significant protection from fluoride toxicity in experimental animal models i.e., preclinical studies. Two clinical studies on medicinal plants were also found in literature showing beneficial yet poorly correlated outcome. Relevant research in this field could lead to development of a potentially useful agent in therapeutic management of fluoride toxicity in humans.

Effectiveness of Silver Diamine Fluoride and Sodium Fluoride Varnish in Preventing New Carious Lesion in Preschoolers: A Randomized Clinical Trial

Introduction

Dental caries is a site-specific, multifactorial chronic disease affected globally. The prevalence of dental caries is strongly associated with social and economic disadvantage, and also the susceptibility of children to dental caries. Dental caries prevention can be achieved with topical fluoride agents. Topical fluoride promotes the remineralization of early carious lesions and reduces the demineralization of healthy enamel.

Aim

The aim of this randomized clinical trial was to compare the effectiveness of silver diamine fluoride (SDF) and sodium fluoride varnish (FV) in preventing new carious lesions in preschoolers.

Materials and methods

This randomized clinical trial was conducted on 285 children aged 3-6 years. Children were randomly allocated into three groups namely, group I-deionized distilled water (DIW), group II-sodium FV, and group III-SDF. The biannual application was performed at an interval of 6 months. New carious lesions were recorded using defs and International Caries Detection and Assessment System (ICDAS II) under LED magnifying loupes. Descriptive and inferential statistics were applied and tabulated using Statistical Package for the Social Sciences (SPSS) 23.0 software.

Result

There was a significant difference seen in the mean values of group III (SDF) when compared with group II (FV) and also between group III (SDF) and group I (DIW) when defs index was used. The mean score of ICDAS II after 12 months in group I (DIW) was -1.171, group II (FV) was -0.690, and group III (SDF) was -0.374.

Conclusion

silver diamine fluoride (SDF) was found to be most effective in preventing dental caries and also it appears to be the most cost-saving fluoride therapy.

How to cite this article

Jain A, Deshpande AN, Shah YS, et al. Effectiveness of Silver Diamine Fluoride and Sodium Fluoride Varnish in Preventing New Carious Lesion in Preschoolers: A Randomized Clinical Trial. Int J Clin Pediatr Dent 2023;16(1):1-8.

Dental Care for Older Adults

There is a global increase in the older population. Unfortunately, dental conditions in the older population can sometimes be poor as a result of worsened physical conditions and the cumulative damage caused by dental diseases in the past. Many suffer from oral diseases such as dental caries and periodontal disease but receive no regular dental care. Oral conditions and systemic problems are interrelated. Chronic medical problems and polypharmacy are common among them. These conditions may lead to xerostomia with or without a decrease in saliva output. Additionally, many older adults have deteriorated masticatory function associated with physical health issues such as frailty. Preventive measures are crucial to stop oral diseases from progressing and the replacement of missing teeth is needed when masticatory function is impaired. Older adults also suffer a higher risk of oral cancer because of their less resilient but more permeable oral mucosa. With the increasing need for elderly dental care, dentists should equip themselves with knowledge and skills in geriatric dentistry. They should help older adults to develop and maintain the functional ability that enables well-being in older age. This communication article aims to discuss the relevant medical conditions, common dental diseases, and dental care for older adults.

Development of Root Caries Prevention by Nano-Hydroxyapatite Coating and Improvement of Dentin Acid Resistance

There is no established method for optimizing the use of dentin to prevent root caries, which are increasing in the elderly population. This study aimed to develop a new approach for root caries prevention by focusing on bioapatite (BioHap), a new biomaterial, combined with fluoride. Bovine dentin was used as a sample, and an acid challenge was performed in three groups: no fluoride (control group), acidulated phosphate fluoride treatment (APF group), and BioHap + APF treatment (BioHap group). After applying the new compound, the acid resistance of dentin was compared with that of APF alone. The BioHap group had fewer defects and an increased surface hardness than the APF group. The BioHap group had the smallest lesion depth and least mineral loss among all groups. Using a scanning electron microscope in the BioHap group showed the closure of dentinal tubules and a coating on the surface. The BioHap group maintained a coating and had higher acid resistance than the APF group. The coating prevents acid penetration, and the small particle size of BioHap and its excellent reactivity with fluoride are thought to have contributed to the improvement of acid resistance in dentin. Topical fluoride application using BioHap protects against root caries.

Optimal Surface Pre-Reacted Glass Filler Ratio in a Dental Varnish Effective for Inhibition of Biofilm-Induced Root Dentin Demineralization

A unique type of dental varnish (DV) containing surface pre-reacted glass (S-PRG) fillers of different concentrations was evaluated to determine the unpresented optimal ratio for inhibiting root dentin bio-demineralization. S-PRG DVs (10% to 40%)—10%-S, 20%-S, 30%-S, and 40%-S—were applied to bovine root dentin blocks and compared with controls—0%-f (no S-PRG) and 5%-NaF (5%-NaF). The Streptococcus mutans biofilm challenge was executed inside and outside an oral biofilm reactor for 7 days. The specimens were examined using a confocal laser scanning microscope and swept-source optical coherence tomography. Furthermore, they were observed using a scanning electron microscope and analyzed using energy-dispersive X-ray spectroscopy. The roughness (SzJIS) due to leaching of DV materials and demineralization depth were significantly less in the S-PRG groups than the control groups (p < 0.05). Complete or partially plugged dentinal tubules (DTs) were observed in 20%-S, 30%-S, and 40%-S, while wide-open DTs were observed more in controls. Cylindrical tags were present in groups containing more than 20% S-PRG. F, Na, Al, and Sr were detected in a higher percentile ratio in the 20%-S, 30%-S, and 40%-S groups compared to 0%-f and 10%-S. Nonetheless, it is suggested that incorporating 20% to 30% S-PRG fillers in DVs would be effective enough as an anti-demineralization coating, together with supplementing minerals; further evaluation is required to validate these findings.

Silver diamine fluoride therapy for dental care

Silver diamine fluoride (SDF) was developed in Japan in the 1960s. It is used to control early childhood caries, arrest root caries, prevent fissure caries and secondary caries, desensitise hypersensitive teeth, remineralise hypomineralised teeth, prevent dental erosion, detect carious tissue during excavation and manage infected root canals. SDF is commonly available as a 38% solution containing 255,000 ppm silver and 44,800 ppm fluoride ions. Silver is an antimicrobial and inhibits cariogenic biofilm. Fluoride promotes remineralisation and inhibits the demineralisation of teeth. SDF also inactivates proteolytic peptidases and inhibits dentine collagen degradation. It arrests caries without affecting dental pulp or causing dental fluorosis. Indirect pulp capping with SDF causes no or mild inflammatory pulpal response. However, direct application of SDF to dental pulp causes pulp necrosis. Furthermore, SDF stains carious lesions black. Patients must be well informed before SDF treatment. SDF therapy is simple, painless, non-invasive, inexpensive, and requires a simple armamentarium and minimal support. Both clinicians and patients generally accept it well. In 2021, the World Health Organization included SDF as an essential medicine that is effective and safe for patients. Moreover, it can be used for caries control during the COVID-19 pandemic because it is non-aerosol-generating and has a low risk of cross-infection.

Evidence on the Use of Mouthwash for the Control of Supragingival Biofilm and Its Potential Adverse Effects

Antimicrobial mouthwash improves supragingival biofilm control when used in conjunction with mechanical removal as part of an oral hygiene routine. Mouthwash is intended to suppress bacterial adhesion during biofilm formation processes and is not aimed at mature biofilms. The most common evidence-based effects of mouthwash on the subgingival biofilm include the inhibition of biofilm accumulation and its anti-gingivitis property, followed by its cariostatic activities. There has been no significant change in the strength of the evidence over the last decade. A strategy for biofilm control that relies on the elimination of bacteria may cause a variety of side effects. The exposure of mature oral biofilms to mouthwash is associated with several possible adverse reactions, such as the emergence of resistant strains, the effects of the residual structure, enhanced pathogenicity following retarded penetration, and ecological changes to the microbiota. These concerns require further elucidation. This review aims to reconfirm the intended effects of mouthwash on oral biofilm control by summarizing systematic reviews from the last decade and to discuss the limitations of mouthwash and potential adverse reactions to its use. In the future, the strategy for oral biofilm control may shift to reducing the biofilm by detaching it or modulating its quality, rather than eliminating it, to preserve the benefits of the normal resident oral microflora.

How do carious root lesions develop after the end of professional preventive measures?—Preliminary findings of a randomized clinical trial

Aim of this randomized clinical trial was to assess the development of root caries lesions with and without (adjuvant) professional prevention treatment over 24 months. 20 participants with two or three non-cavitated root carious lesions were included (n = 52), whereby lesions were randomly assigned to one out of three groups depending on varnish application (CF: Cervitec F [n = 20], P: placebo [n = 20], DP: Duraphate [n = 12]). All lesions were assessed by quantitative light-induced fluorescence (QLF; QRayCam); following outcome parameters were analyzed: fluorescence loss (ΔF %), lesion volume (ΔQ %µm²) and bacterial activity (ΔR %). Professional tooth cleaning and adjuvant varnish application were performed at baseline, after 3, 6, and 9 months. A follow-up examination was performed 1 year after preventive care with varnish application 24 months after baseline. ∆F showed a significant time effect in CF (p = 0.03), which was not confirmed in post hoc analysis (p > 0.05). For P and DP, no time effect was detected (p > 0.05). ∆Q was significantly higher 12 months after baseline in CF (p = 0.02). In P, a significant time effect occurred (p = 0.01), without significant results in post hoc testing. ∆R showed higher values at baseline vs. 12 months in CF (p = 0.03) and 24 months compared to 12 months in DP (p = 0.02). Professional preventive treatment inhibited the progression of root caries lesions beyond their termination for 12 months, irrespective of an adjunctive varnish application. Preventive measures have a long-term effect on root carious lesions, even 1 year after their termination.

Bis(2-, 3-, 4-carboxyethylpyridinium) hexafluorosilicates as potential caries prophylactic agents

Interaction of 2-, 3-, 4-carboxyethylpyridines (L1, L2, L3) with fluorosilicic acid results in the corresponding bis(pyridinium) hexafluorosilicates I-III, characterized by elemental analysis, IR, ¹ H, ¹⁹ F nuclear magnetic resonance (NMR), and mass spectrometry, solubility data, and X-ray crystallography. Crystallographic data: Fdd2, Z = 8, a = 28.610(2) Å, b = 18.8378(14) Å, c = 7.3236(5) Å (I); P-1, Z = 1, a = 6.2712(4) Å, b = 7.1706(5) Å, c = 10.9721(7) Å, α = 102.514(6)°, β = 97.037(5)°, γ = 93.640(6)° (II); P2₁ /c, Z = 2, a = 10.0345(6) Å, b = 9.8734(5) Å, c = 9.4704(6) Å, β = 94.347(6)° (III). The dominant intermolecular contacts from the Hirshfeld surface analysis are H^… F/F^… H, H^… H, and H^… O/O^… H with percentages of 33.3%-34.5%, 26.4%-30.0%, and 16.0%-21.8%. The infrared spectra for I-III exhibit stretching vibrations ν(N⁺ H) at 3300-3050 cm^-1 ; stretching and deformation vibrations ν(SiF) and δ(SiF₂ ) for [SiF₆ ]^2- anions are registered near 740 cm^-1 and in the range of 480-440 cm^-1 . In the ¹⁹ F NMR spectra of aqueous solutions of I-III, strong singlet signals of the [SiF₆ ]^2- anion were registered at δ(F) = -133.35 ppm (I), -131.43 ppm (II), -129.02 ppm (III) with two satellites due to the spin-spin interaction ²⁹ Si-¹⁹ F (J(²⁹ Si-¹⁹ F) = 107.5 Hz (II), 107.6 Hz (III)). I-III reveal high solubility in water and dimethyl sulfoxide and very poor solubility in methanol and ethanol. All compounds demonstrate noticeable anticaries activity and absence of hepatotoxic effects, and bis(3-carboxyethylpyridinium) hexafluorosilicate II displays the highest caries-preventive efficacy, which significantly exceeds values for the reference preparations, NaF and (NH₄ )₂ [SiF₆ ].

In vitro Evaluation of Surface Free Energy of Dentin after Treatment with Sodium Trimetaphosphate Associated or Not with Fluoride, Exposed or Not to Calcium

It has been stated that sodium trimetaphosphate (TMP) promotes a more anionic dentin surface inducing greater calcium (Ca) and phosphate precipitation. The aim of the present study was to evaluate in vitro the surface free energy (γs) of dentin after treatment with TMP associated or not with fluoride (F), exposed or not to Ca, as well as the adsorption of TMP, F, and Ca by dentin. Bovine dentin blocks (n = 12 blocks/group) were treated with solutions containing TMP at 0, 1, 3, or 9 (w/v) followed or not by the application of Ca. These solutions were or were not associated to 1,100 ppm F. F, Ca, and TMP were determined in the solutions before and after the treatment to calculate the adsorption by dentin. To analyze the γs of dentin, the apolar (γsLW), and polar (γsAB), components were determined by contact angle measurement. Data were submitted to 2-way ANOVA followed by the Student-Newman-Keuls test (p < 0.05). TMP reduces γs of dentin and increases electron donor sites (γs-). Higher values of γs- led to higher adsorption of Ca (p < 0.001). The F/TMP association did not change γs or γsLW and reduced the values of γs-, but the adsorption of Ca was higher. There was correlation between the adsorption of TMP and γs- (Pearson's r = 0.801; p < 0.001) and F (Pearson's r = 0.871, p < 0.001). It is possible to conclude that TMP increased γs- and Ca adsorption, and reduced γs. The association with F increased the adsorption of TMP without rising γs-; however, there was higher adsorption of Ca.

Oral Health Status of Residents in Jiangsu Province, China: An Epidemiologic Survey

Introduction

This study was conducted to characterise the oral health conditions of residents in Jiangsu Province, China.

Methods

In this descriptive study, 5 groups of participants were selected by a multistage stratified equal capacity random sampling, including 3- to 5-year-olds, 12- to 15-year-olds, 35- to 44-year-olds, 55- to 64-year-olds, and 65- to 74-year-olds. The data were collected by using the fifth edition of Oral Health Surveys-Basic Methods recommended by the World Health Organization (WHO).

Results

In these 5 groups, the mean DMFT/dmft of coronal caries were 3.07, 0.69, 4.03, 7.15, and 11.97, respectively, resulting in prevalence rates of 59.69%, 34.98%, 52.05%, 56.86%, and 72.19%, respectively. However, the filling rates were low in all age groups (1.88%, 17.53%, 29.88%, 16.13%, and 19.36%, respectively). Only 3.58% of the 12-year-old participants had good pit and fissure sealants. The adults include three groups, 35- to 44-year-olds, 55- to 64-year-olds, and 65- to 74-year-olds, and the prevalence rates of clinical attachment loss (CAL ≥4 mm) were 32.19%, 76.47%, and 85.43%, respectively. The proportions of adult groups with implant dentures, fixed dentures, removable partial dentures, complete dentures, and substandard dentures were 0%, 26.44%, 11.11%, 0.67%, and 4.89%, respectively. Additionally, 49.64% of adults had missing teeth that were not replaced.

Conclusions

Dental caries and periodontal disease were frequent and common in Jiangsu, China. But only a few of the residents sought treatment. Oral diseases continued to be a major problem for local residents.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2020 professional literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to this work to cover this broad topic. Specific subject areas addressed include prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders (TMDs); sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence day-to-day dental treatment decisions with a keen eye on future trends in the profession. With the tremendous volume of dentistry and related literature being published today, this review cannot possibly be comprehensive. The purpose is to update interested readers and provide important resource material for those interested in pursuing greater detail. It remains our intent to assist colleagues in navigating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the dental patients they encounter.

1,2-Phenylene-Incorporated Smallest Expanded Calix[4]pyrrole via One-Step Synthesis of Tetrapyrrane: A Fluorescent Host for Fluoride Ion

Synthesis of tetrapyrrane 8 from acetone and pyrrole via one-step condensation was achieved for the first time along with a much-improved yield of the tripyrrane 9. Diborylation of the tetrapyrrane and subsequent "1 + 1" cyclocoupling with 1,2-diiodobenzene following the Suzuki protocol generated novel o-phenylene incorporated macrocycle belonging to the smallest meso-expanded calix[4]pyrrole family. The latter macrocycle displays exclusive turn-on fluorescence sensing of fluoride ion upon complexation via a unique partial cone conformation supported by DFT analysis in acetonitrile solvent.

Assessment of the preventive effects of Nd:YAG laser associated with fluoride on enamel caries using optical coherence tomography and FTIR spectroscopy

Objective

This in vitro study characterized and monitored, by Optical Coherence Tomography (OCT) and Fourier Transformed Infrared Spectroscopy (FTIR), the effects of the association of acidulated phosphate fluoride gel (APF-gel) and Nd:YAG (neodymiun:yttrium-aluminum-garnet) laser, as sequencial treatments, in the prevention of incipient enamel caries lesions.

Methods

120 human enamel samples were randomized into 3 groups (n = 40): APF-gel (1.23% F^-, 4 min.); Laser+APF (Nd:YAG laser irradiation—0.6W, 84.9J/cm², 10Hz, followed by APF-gel); and APF+Laser (APF-gel followed by laser irradiation). The samples were subjected to a 15-day pH-cycling, evaluated by OCT (quantification of optical attenuation coefficient–OAC) and FTIR (analysis of carbonate and phosphate content) before treatments, after treatments, and on the 5^th, 10^th and 15^th days of pH-cycling. The statistical analysis was performed (α = 5%).

Results

The Optical Attenuation Coefficient (OAC) assessed by OCT increases with the progression of demineralization, and the Laser+APF presented the highest values of OAC in 10^th and 15^th days of pH-cycling. Nd:YAG decreased the carbonate content after treatment regardless of the application order of the APF-gel, while APF-gel did not interfere in the composition of enamel. The carbonate content was also changed in the first 5 days of the pH-cycling in all groups.

Conclusion

Nd:YAG laser irradiation before or after the application of APF-gel did not influence the appearance of incipient caries lesions, showing no synergistic effect. Regardless of the application order of the APF-gel, laser irradiation reduces the carbonate content of the enamel, which also changes during the demineralization process. However, irradiation before the application of APF-gel increased the speed of progression of the lesions, which positively impacts public health as it can prevent caries disease, even in high risk individuals. OCT and FTIR are suitable for assessing this effect.

Effect of TiF4/NaF and chitosan solutions on the development of enamel caries under a microcosm biofilm model

OBJECTIVES

To evaluate the effect of experimental solutions containing TiF₄/NaF and chitosan on bacterial species and on enamel caries prevention.

METHODS

Microcosm biofilm was produced from human saliva mixed with McBain saliva (0.2% sucrose) on bovine enamel for five days, under 5% CO₂ and 37 °C. From the second day until the end, the treatments were applied (1 × 60 s/day): (1) NaF (500 ppm F^-, positive control); (2) TiF₄ and NaF (TiF₄: 190 ppm Ti⁴⁺ and 300 ppm F^-; NaF: 190 ppm F^-); (3) similar to 2 plus 0.5% chitosan (Ch 500 mPas, 75% deacetylation); (4) phosphate buffer solution (negative control); and (5) 0.5% chitosan (Ch 500 mPas, 75% deacetylation). CFU counting was performed for total microorganism, total streptococcus, total lactobacillus and Streptococcus mutans. Enamel demineralization was measured by transverse microradiography-TMR. The data were compared using ANOVA/Tukey or Kruskal-Wallis/Dunn tests (p < .050).

RESULTS

No differences were found between the treatments with respect to CFU counting (ANOVA, p > .050). Enamel treated with TiF₄/NaF plus chitosan solution presented the lowest demineralization compared to the negative control and pure chitosan solution. On the other hand, this experimental solution did not significantly differ from TiF₄/NaF and NaF solutions, being all of them able to significantly reduce mineral loss (50-74%), but only TiF₄/NaF plus chitosan reduced lesion depth (55%) compared to the negative control (p = .001).

CONCLUSION

TiF₄/NaF plus chitosan solution had no antimicrobial effect, but it was able to reduce enamel caries development in 79% compared to control under this model.

CLINICAL SIGNIFICANCE

This study showed that TiF₄/NaF plus chitosan solution had no antimicrobial effect, but it was able to reduce enamel caries development under a microcosm biofilm model.

Is there a preferable management for root caries in middle-aged and older adults? A systematic review

Aim This systematic review aimed to critically summarise the results of clinical studies investigating agents able to: stop the progression of carious lesions; stop the development of new root carious lesions; preserve the vitality of the infected dental tissues; and increase the surface hardness or change of surface texture, in middle-age and older adults.Methods PubMed, Scopus, and Web of Science were searched systematically, following PRISMA guidelines. Clinical trials published from 2011 to 2020 (March) were included. This systematic review is registered in the PROSPERO database (CRD42018104399). Languages were restricted to English.Results Thirteen of 312 studies were eligible for this review. Eight agents were identified in the studies and their efficacy was assessed using different methods. The agents that presented valuable results on preventing or arresting root caries were 38% silver diamine fluoride (SDF), arginine-containing toothpaste and high-fluoride toothpastes.Conclusions Based on the selected studies' findings, annual applications of 38% SDF could be the most effective treatment for root caries in older adults. In addition, the daily use of a 1.5% arginine toothpaste or a high-fluoride toothpaste could also be recommended. More research on root caries-specific diagnostic methods, especially at very early stages, is necessary.

Effects of silver diamine fluoride preparations on biofilm formation of Streptococcus mutans

Effects of silver diamine fluoride preparations (SDFs) on cariogenic biofilm formation on root dentin (RD) were investigated. Streptococcus mutans (S. mutans) biofilms were formed on bovine RD blocks coated with one of three the SDFs (38%-SDF, 3.8%-SDF and 35%-SDF+potassium-iodide; SDF+KI) and a non-coated Control which were quantified (spectrometric-measurement) and thickness measured (optical coherence tomography) after 20 h. Bacterial viability test (BacLight) and biofilm-morphometry (SEM) of 2 h biofilms were also performed. The amounts of biofilms (bacteria and water insoluble glucan) and the thickness of biofilm were minimum on 38%-SDF specimen; 3.8%-SDF and SDF+KI had significantly more than that, but had significantly less than Control (p<0.05). Most S. mutans cells found dead and morphology damaged by 38%-SDF. Some dead bacteria and remarkably damaged biofilms were observed in case of 3.8%-SDF and SDF+KI. Inhibition potential of 3.8%-SDF and SDF+KI on S. mutans biofilm formation is almost similar, although not equivalent to 38%-SDF.

Salivary fluoride concentration and retention after rinsing with 0.05 and 0.2% sodium fluoride (NaF) compared with a new high F rinse containing 0.32% NaF

OBJECTIVE

To compare salivary fluoride (F) concentration and F retention after rinsing with a new 0.32% sodium fluoride (NaF) rinse and conventional 0.05 and 0.2% NaF rinses.

METHODS

Seventeen subjects (aged 22-26 years), with normal salivary secretion rates, participated in a double blind, cross-over study. In three separate sessions with a minimum washout period of 48 h, they rinsed for 1 min with 10 ml of 0.05, 0.2 or 0.32% NaF mouthrinse. Unstimulated whole saliva was collected before (baseline: 0 min) and after 1, 3, 5, 10, 20, 30, 45 and 60 min. The F concentration was plotted against time, and the area under the curve (AUC) calculated. Salivary F concentration and F retention for the three mouthrinses were compared by a randomized block test, followed by Tukey's test and a paired 2-tailed test.

RESULTS

There was a clear dose-response for AUC 3-60 min; 0.32% > 0.2% > 0.05% (p < .05). The mean F retention was 0.25 mg for 0.05% NaF, 0.86 mg F for 0.2% Na and 1.31 mg F for 0.32% NaF, (p < .05).

CONCLUSIONS

The higher salivary F concentration over time and the higher F retention after rinsing with an 0.32% NaF solution suggests a potential application in prevention of caries and dental erosion.

Assessment of knowledge and perception about silver diamine fluoride (SDF) for treating older adults among graduating dental students

PURPOSE/OBJECTIVES

Silver diamine fluoride (SDF) is a promising therapy for arresting and preventing caries in difficult to treat, high-risk populations, including institutionalized older adults. This study investigates the knowledge and perceptions about SDF of graduating dental students in multiple U.S. dental schools, as well as their willingness to use SDF in their practices.

METHODS

A survey was designed consisting of 21 total questions: 6 questions regarding students' demographic information and their SDF content exposure contextualization, 8 questions tailored to investigate 2 domains regarding students' knowledge about SDF (properties and indication), and 7 questions aiming to investigate 3 domains regarding students' perceptions about SDF (SDF usefulness, appropriateness of using SDF, and willingness to use SDF when in private practice). The survey was then distributed to graduating dental students at 7 U.S. dental schools.

RESULTS

A total of 386 surveys (response rate of 55%) was collected from 7 schools in the Spring of 2019. The median score resulting from the SDF content exposure questions was 3 (SD = 1.43) from a range of 0-5. The median score from knowledge about SDF properties was 4 (SD = 1.18) from a range of 0 to 6. In the multivariate analysis, a linear model found that the covariates "SDF Usefulness", "SDF Appropriateness" and "SDF Patient Willingness to Use" were significantly associated with higher student willingness to use SDF (R²  = 0.395).

CONCLUSION

The results indicated that the graduating students have a positive perception of SDF regarding its usefulness and appropriateness. Graduating students appear inclined to utilize SDF upon entering private practice.

National Study of Adult Oral Health 2017-18: root caries

BACKGROUND

The prevalence of root caries in Australia is expected to increase due to an ageing population and increase in tooth retention. This report presents findings from the Australian National Study of Adult Oral Health 2017-18.

METHODS

A stratified random sample of 15 731 Australians aged ≥15 years participated in a telephone or online survey. Of those, 5022 dentate people underwent an oral assessment. Carious root surfaces were defined as ≥1 mm of affected dentine/cementum. Prevalence was defined as the percentage with ≥one natural tooth with untreated caries on root surfaces. Severity was measured as the mean number of root surfaces with caries.

RESULTS

Prevalence of untreated root caries in the Australian adult dentate population was 8.2% and increased with increasing age (range 2%-17.8%). Men (9.3%) compared to women (7.2%), people living in remote (18.0%) versus regional (9.3%) and major cities (7.6%), and those with the lowest household income (15.4%) compared to middle (7.6%) and highest tertile (3.2%) had untreated root caries. The average number of decayed or filled root surfaces in the Australian adult population was 1.1 (95% CI 0.9, 1.2).

CONCLUSIONS

Root caries was associated with older age, living outside a major city and lower income.

Tooth Enamel and its Dynamic Protein Matrix

Tooth enamel is the outer covering of tooth crowns, the hardest material in the mammalian body, yet fracture resistant. The extremely high content of 95 wt% calcium phosphate in healthy adult teeth is achieved through mineralization of a proteinaceous matrix that changes in abundance and composition. Enamel-specific proteins and proteases are known to be critical for proper enamel formation. Recent proteomics analyses revealed many other proteins with their roles in enamel formation yet to be unraveled. Although the exact protein composition of healthy tooth enamel is still unknown, it is apparent that compromised enamel deviates in amount and composition of its organic material. Why these differences affect both the mineralization process before tooth eruption and the properties of erupted teeth will become apparent as proteomics protocols are adjusted to the variability between species, tooth size, sample size and ephemeral organic content of forming teeth. This review summarizes the current knowledge and published proteomics data of healthy and diseased tooth enamel, including advancements in forensic applications and disease models in animals. A summary and discussion of the status quo highlights how recent proteomics findings advance our understating of the complexity and temporal changes of extracellular matrix composition during tooth enamel formation.

Assessment of risk factors for early childhood caries at different ages in Shandong, China and reflections on oral health education: a cross-sectional study

BACKGROUND

The high prevalence of early childhood caries (ECC) is widespread around the world, and oral health education (OHE) plays a vital role in preventing ECC. Numerous studies on ECC risk factor assessment have assisted us in enriching the content of OHE. The objective of this study was to further assess independent risk factors for ECC at different ages to provide evidence and insights for OHE.

METHODS

Children aged 3-5 years old (N = 1301) in Shandong Province were enrolled in this cross-sectional study. Data about oral health status and caregivers' oral health knowledge, attitude, and practice (KAP) were extracted from the 4th National Oral Health Survey of China. The associations between ECC prevalence and various KAP variables were tested with chi-square tests, bivariate analysis and multivariable logistic regression analyses.

RESULTS

The ECC prevalence in Shandong Province was 64.6%, and the dmft mean was 3.15. The independent variables with an increased risk for ECC were age, feeding method within 6 months of birth, bedtime sugar frequency, experience of toothache over the past year and dental visits (P < 0.05, chi-square tests). Complete breastfeeding within 6 months of birth primarily contributed to the high ECC risk of the 3-year-old group (OR: 3.39, 95% CI: 1.41-8.17), while high frequency bedtime sweet consumption mainly contributed to that of the 5-year-old group (OR: 3.22, 95% CI: 1.03-10.06; logistic regression analysis). Tooth brushing was not associated with ECC in this study, and some positive knowledge and attitude variables were positively correlated with a high risk of ECC.

CONCLUSION

These data provide evidence to suggest that the ECC-related risk factors at different ages are inconsistent, which provides some insights for OHE. We should highlight the effects of feeding methods in the early stages of deciduous dentition and sugar habits in the late stages of deciduous dentition on ECC, as well as encourage preventive dental visit and supplemental training for oral health practices.