Should We Wait to Brush Our Teeth?: A Scoping Review Regarding Dental Caries and Erosive Tooth Wear

BACKGROUND

Tooth brushing is a universal recommendation. However, the recommendations related to the time of its execution are conflicting, especially when dealing with patients at risk of erosive tooth wear (ETW) or dental caries.

SUMMARY

Our objective was to summarize the evidence on the timing of brushing with fluoridated toothpaste in relation to ETW and cariogenic dietary challenges. We conducted a scoping review following the PRISMA-ScR checklist, using three databases searching for in-vivo, in-situ, or in-vitro studies involving human teeth exposed to either a cariogenic or an erosive challenge. Only models including human saliva and fluoride were assessed. Data selection, extraction, and risk of bias analysis were done in duplicate and independently. From 1,545 identified studies, 17 (16 related to ETW and 1 to dental caries) were included. Most evidence (n=10) supported that brushing with a fluoride-containing product does not increase ETW, independent of the moment of brushing. Delaying tooth brushing up to 1 hour (n=4) or individualized recommendations based on the patient's problem (n=2) were less frequent. Only one study reported that brushing pre- or post-meal does not affect Streptococcus mutans counts. Most data was in-situ (n=13), and the overall study quality was judged as sufficient/low risk of bias.

KEY MESSAGES

Although the available evidence lacked robust clinical studies, tooth brushing using fluoridated products immediately after an erosive challenge does not increase the risk of ETW and can be recommended, which is in line with recommendations for dental caries prevention. Furthermore, we suggest updating the international guidelines to promote individualized recommendations based on risk factors to prevent either ETW or dental caries.

Iron oxide nanozymes stabilize stannous fluoride for targeted biofilm killing and synergistic oral disease prevention

Dental caries (tooth decay) is the most prevalent human disease caused by oral biofilms, affecting nearly half of the global population despite increased use of fluoride, the mainstay anticaries (tooth-enamel protective) agent. Recently, an FDA-approved iron oxide nanozyme formulation (ferumoxytol, Fer) has been shown to disrupt caries-causing biofilms with high specificity via catalytic activation of hydrogen peroxide, but it is incapable of interfering with enamel acid demineralization. Here, we find notable synergy when Fer is combined with stannous fluoride (SnF 2 ), markedly inhibiting both biofilm accumulation and enamel damage more effectively than either alone. Unexpectedly, our data show that SnF 2 enhances the catalytic activity of Fer, significantly increasing reactive oxygen species (ROS) generation and antibiofilm activity. We discover that the stability of SnF 2 (unstable in water) is markedly enhanced when mixed with Fer in aqueous solutions without any additives. Further analyses reveal that Sn 2+ is bound by carboxylate groups in the carboxymethyl-dextran coating of Fer, thus stabilizing SnF 2 and boosting the catalytic activity. Notably, Fer in combination with SnF 2 is exceptionally effective in controlling dental caries in vivo , preventing enamel demineralization and cavitation altogether without adverse effects on the host tissues or causing changes in the oral microbiome diversity. The efficacy of SnF 2 is also enhanced when combined with Fer, showing comparable therapeutic effects at four times lower fluoride concentration. Enamel ultrastructure examination shows that fluoride, iron, and tin are detected in the outer layers of the enamel forming a polyion-rich film, indicating co-delivery onto the tooth surface. Overall, our results reveal a unique therapeutic synergism using approved agents that target complementary biological and physicochemical traits, while providing facile SnF 2 stabilization, to prevent a widespread oral disease more effectively with reduced fluoride exposure.

How to Intervene in the Caries Process in Older Adults: A Joint ORCA and EFCD Expert Delphi Consensus Statement

AIM

To provide recommendations for dental clinicians for the management of dental caries in older adults with special emphasis on root caries lesions.

METHODS

A consensus workshop followed by a Delphi consensus process were conducted with an expert panel nominated by ORCA, EFCD, and DGZ boards. Based on a systematic review of the literature, as well as non-systematic literature search, recommendations for clinicians were developed and consented in a two-stage Delphi process.

RESULTS

Demographic and epidemiologic changes will significantly increase the need of management of older adults and root caries in the future. Ageing is associated with a decline of intrinsic capacities and an increased risk of general diseases. As oral and systemic health are linked, bidirectional consequences of diseases and interventions need to be considered. Caries prevention and treatment in older adults must respond to the patient's individual abilities for self-care and cooperation and often involves the support of caregivers. Systemic interventions may involve dietary counselling, oral hygiene instruction, the use of fluoridated toothpastes, and the stimulation of salivary flow. Local interventions to manage root lesions may comprise local biofilm control, application of highly fluoridated toothpastes or varnishes as well as antimicrobial agents. Restorative treatment is often compromised by the accessibility of such root caries lesions as well as the ability of the senior patient to cooperate. If optimum restorative treatment is impossible or inappropriate, long-term stabilization, e.g., by using glass-ionomer cements, and palliative treatments that aim to maintain oral function as long and as well as possible may be the treatment of choice for the individual.

How to intervene in the caries process in adults: proximal and secondary caries? An EFCD-ORCA-DGZ expert Delphi consensus statement

OBJECTIVES

To provide consensus recommendations on how to intervene in the caries process in adults, specifically proximal and secondary carious lesions.

METHODS

Based on two systematic reviews, a consensus conference and followed by an e-Delphi consensus process were held with EFCD/ORCA/DGZ delegates.

RESULTS

Managing an individual's caries risk using non-invasive means (oral hygiene measures including flossing/interdental brushes, fluoride application) is recommended, as both proximal and secondary carious lesions may be prevented or their activity reduced. For proximal lesions, only cavitated lesions (confirmed by visual-tactile, or radiographically extending into the middle/inner dentine third) should be treated invasively/restoratively. Non-cavitated lesions may be successfully arrested using non-invasive measures in low-risk individuals or if radiographically confined to the enamel. In high-risk individuals or if radiographically extended into dentine, for these lesions, additional micro-invasive (lesion sealing and infiltration) treatment should be considered. For restoring proximal lesions, adhesive direct restorations allow minimally invasive, tooth-preserving preparations. Amalgams come with a lower risk of secondary lesions and may be preferable in more clinically complex scenarios, dependent on specific national guidelines. In structurally compromised (especially endodontically treated) teeth, indirect cuspal coverage restorations may be indicated. Detection methods for secondary lesions should be tailored according to the individual's caries risk. Avoiding false positive detection and over-treatment is a priority. Bitewing radiographs should be combined with visual-tactile assessment to confirm secondary caries detections. Review/refurbishing/resealing/repairing instead of replacing partially defective restorations should be considered for managing secondary caries, if possible.

CONCLUSIONS

An individualized and lesion-specific approach is recommended for intervening in the caries process in adults.

CLINICAL SIGNIFICANCE

Dental clinicians have an increasing number of interventions available for the management of dental caries. Many of them are grounded in the growing understanding of the disease. The best evidence, patients' expectations, clinicians' expertise, and the individual clinical scenario all need to be considered during the decision-making process.

Secondary caries: what is it, and how it can be controlled, detected, and managed?

OBJECTIVES

To assess how to control, detect, and treat secondary caries. This review serves to inform a joint ORCA/EFCD consensus process.

METHODS

Systematic and non-systematic reviews were performed or consulted and narratively synthesized.

RESULTS

Secondary (or recurrent) caries is defined as a lesion associated with restorations or sealants. While the restorative material itself has some influence on secondary caries, further factors like the presence and size of restoration gaps, patients' caries risk, and the placing dentist's experience seem more relevant. Current detection methods for secondary caries are only sparsely validated and likely prone for the risk of over-detection. In many patients, it might be prudent to prioritize specific detection methods to avoid invasive overtreatment. Detected secondary caries can be managed either by repair of the defective part of the restoration or its complete replacement.

CONCLUSIONS

There is sparse data towards the nature of secondary caries and how to control, detect, and treat it.

CLINICAL SIGNIFICANCE

Despite often claimed to be a major complication of restorations, there is surprisingly little data on secondary caries. Longer-term studies may be needed to identify differences in secondary caries risk between materials and to identify characteristic features of progressive lesions (i.e., those in need of treatment).

Topical ferumoxytol nanoparticles disrupt biofilms and prevent tooth decay in vivo via intrinsic catalytic activity

Ferumoxytol is a nanoparticle formulation approved by the U.S. Food and Drug Administration for systemic use to treat iron deficiency. Here, we show that, in addition, ferumoxytol disrupts intractable oral biofilms and prevents tooth decay (dental caries) via intrinsic peroxidase-like activity. Ferumoxytol binds within the biofilm ultrastructure and generates free radicals from hydrogen peroxide (H₂O₂), causing in situ bacterial death via cell membrane disruption and extracellular polymeric substances matrix degradation. In combination with low concentrations of H₂O₂, ferumoxytol inhibits biofilm accumulation on natural teeth in a human-derived ex vivo biofilm model, and prevents acid damage of the mineralized tissue. Topical oral treatment with ferumoxytol and H₂O₂ suppresses the development of dental caries in vivo, preventing the onset of severe tooth decay (cavities) in a rodent model of the disease. Microbiome and histological analyses show no adverse effects on oral microbiota diversity, and gingival and mucosal tissues. Our results reveal a new biomedical application for ferumoxytol as topical treatment of a prevalent and costly biofilm-induced oral disease.

Ferumoxytol is a nanoparticle formulation approved for systemic use to treat iron deficiency. Liu et al. show that topical use of ferumoxytol, in combination with low concentrations of H₂O₂, disrupts intractable oral biofilms and prevents tooth decay in vitro and in an animal model.

In vitro Detection of Occlusal Caries on Permanent Teeth by a Visual, Light-Induced Fluorescence and Photothermal Radiometry and Modulated Luminescence Methods

Background: The paradigm shift towards the nonsurgical management of dental caries relies on the early detection of the disease. Detection of caries at an early stage is of unequivocal importance for early preventive intervention. Objective: The aim of this in vitro study is to evaluate the performance of a visual examination using the International Caries Detection and Assessment System (ICDAS) criteria, two quantitative light-induced fluorescence (QLF) systems - Inspektor™ Pro and QLF-D Biluminator™ 2 (Inspektor Research Systems B.V., Amsterdam, The Netherlands) - and a photothermal radiometry and modulated luminescence, The Canary System® (Quantum Dental Technologies, Toronto, Ont., Canada) on the detection of primary occlusal caries on permanent teeth. Methods: A total of 60 teeth with occlusal surface sites ranging from sound to noncavitated lesions (ICDAS 0-4) were assessed with each detection method twice in a random order. Histological validation was used to compare methods for sensitivity, specificity, percent correct, and the area under the receiver operating characteristic curve (AUC), at standard and optimum sound thresholds. Interexaminer agreement and intraexaminer repeatability were measured using intraclass correlation coefficients. Results: Interexaminer agreement ranged between 0.48 (The Canary System®) and 0.96 (QLF-D Biluminator™ 2). Intraexaminer repeatability ranges were 0.33-0.63 (The Canary System®) and 0.96-0.99 (QLF-D Biluminator™ 2). The sensitivity range was 0.75-0.96 while that of specificity was 0.43-0.89. The AUC were 0.79 (The Canary System®), 0.87 (ICDAS), 0.90 (Inspektor™ Pro), and 0.94 (QLF-D Biluminator™ 2). Conclusion: ICDAS had the best combination of sensitivity and specificity followed by QLF-D Biluminator™ 2 at optimum threshold.

Caries management pathways preserve dental tissues and promote oral health

In May 2012, cariologists, dentists, representatives of dental organizations, manufacturers, and third party payers from several countries, met in Philadelphia, Pennsylvania, to define a common mission; goals and strategic approaches for caries management in the 21th century. The workshop started with an address by Mr. Stanley Bergman, CEO of Henry Schein Inc. which focused on the imperative for change in academia, clinical practice, and public health. For decades, new scientific evidence on caries and how it should be managed have been discussed among experts in the field. However, there has been some limited change, except in some Scandinavian countries, in the models of caries management and reimbursement which have been heavily skewed toward 'drilling and filling'. There is no overall agreement on a caries' case definition or on when to surgically intervene. The participants in the workshop defined a new mission for all caries management approaches, both conventional and new. The mission of each system should be to preserve the tooth structure, and restore only when necessary. This mission marks a pivotal line for judging when to surgically intervene and when to arrest or remineralize early noncavitated lesions. Even when restorative care is necessary, the removal of hard tissues should be lesion-focused and aim to preserve, as much as possible, sound tooth structure. Continuing management of the etiological factors of caries and the use of science-based preventive regimens also will be required to prevent recurrence and re-restoration. These changes have been debated for over a decade. The Caries Management Pathways includes all systems and philosophies, conventional and new, of caries management that can be used or modified to achieve the new mission. The choice of which system to use to achieve the mission of caries management is left to the users and should be based on the science supporting each approach or philosophy, experience, utility, and ease of use. This document also presents a new 'Caries Management Cycle' that should be followed regardless of which approach is adopted for caries prevention, detection, diagnosis, and treatment. To aid success in the adoption of the new mission, a new reimbursement system that third party payers may utilize is proposed (for use by countries other than Scandinavian countries or other countries where such systems already exist). The new reimbursement/incentive model focuses on the mission of preservation of tooth structure and outcomes of caries management. Also described, is a research agenda to revitalize research on the most important and prevalent world-wide human disease. The alliance of major dental organizations and experts that started in Philadelphia will hopefully propel over the next months and years, a change in how caries is managed by dentists all over the world. A new mission has been defined and it is time for all oral health professionals to focus on the promotion of oral health and preservation of sound teeth rather than counting the number of surgical restorative procedures provided.

Exploratory Randomized Clinical Trial of an Experimental Gel-to-Foam Fluoride Dentifrice Formulation Using an In Situ Caries Model

OBJECTIVE

To evaluate the in situ caries performance and safety of two experimental fluoride dentifrice formulations (1450 ppm fluoride) with and without 2% isopentane as an excipient, in comparison to a positive control, currently marketed dentifrice (1450 ppm fluoride) and a negative control dentifrice (0 ppm fluoride).

METHODS

This was a single-center, examiner-blind, randomized, controlled, four-treatment cross-over study. During each treatment period, the subject wore a modified mandibular partial denture fitted with two gauze-covered, partially demineralized human enamel specimens, and brushed at home for one timed minute, twice daily, for two weeks. At the end of each treatment period, the enamel specimens were removed from the dentures for analysis. During the week between treatment periods, subjects returned to their usual dental hygiene practices for four to five days, received a dental prophylaxis, and used a study-designated non-fluoride dentifrice for two to three days before starting the next treatment. Treatment effect on enamel specimen remineralization was assessed by surface microhardness (SMH). Enamel fluoride uptake was assessed using microdrill enamel biopsy.

RESULTS

All fluoride-containing dentifrices demonstrated significant, superior SMH recovery and levels of fluoride uptake compared to the negative control dentifrice. No significant differences were observed for either efficacy variable between the experimental dentifrice formulations and the positive control dentifrice. No significant difference was observed between the 2% isopentane dentifrice and the 0% isopentane dentifrice for SMH recovery.

CONCLUSION

The addition of 2% isopentane did not positively or negatively affect fluoride efficacy in this model.

Traditional preventive treatment options

Preventive treatment options can be divided into primary, secondary and tertiary prevention techniques, which can involve patient- or professionally applied methods. These include: oral hygiene (instruction), pit and fissure sealants ('temporary' or 'permanent'), fluoride applications (patient- or professionally applied), dietary assessment and advice (modification), other measures to help remineralize demineralized tissue and other measures to help modify the biofilm to reduce the cariogenic challenge. There is a considerable body of strong evidence supporting the use of specific techniques for primary prevention of caries in children, e.g. pit and fissure sealants and topically applied fluorides (including patient-applied fluoride toothpastes and professionally applied fluoride varnishes), but limited strong evidence for these techniques for secondary prevention--i.e. where early to established lesions with ICDAS codes 1-4 (and also the severer lesions coded 5 or 6) are involved--and in relation to adults. This lack of evidence reflects a shortage of high-quality trials in the area, as opposed to a series of good studies showing no effect. Since there is also limited longitudinal evidence supporting conventional operative care, and since controlling the caries process prior to first restoration is the key to breaking the repair cycle and improving care for patients, future research should address the shortcomings in the current level of supporting evidence for the various traditional preventive treatment options.

Xylitol: effects on the acquisition of cariogenic species in infants

PURPOSE

The purpose of this study was to examine the effects of xylitol gum (XG) on the acquisition pattern of 39 bacterial species, including mutans streptococci (MS), in infants.

METHODS

Ninety-seven mothers (MS counts > 10(5) CFU/ml) were randomly divided into 4 groups and received: (1) XG (4.2 gm/day); (2) XG (6 months after baseline exams); (3) sorbitol gum (4.2 gm/day); or (4) no gum. Groups 1 and 3 chewed gum 3 times a day for 9 months. Microbiota of plaque and saliva samples from the mother-child pairs were analyzed by culturing and via checkerboard DNA-DNA hybridization.

RESULTS

MS was isolated from 33% of the predentate infant (< or =5 months old) baseline saliva samples and from 41% of the saliva and 65% of the plaque samples at the final visit. At baseline, positive responses to "mother's checking of baby's food temperature using baby's spoon" and "starting a bottle after stopping breast-feeding" were significant predictors (P = .009 and P < .001, respectively) of infant's total streptococci counts. At the final visit (9 months later), there were no significant differences between treatment groups for infants' 39 microbial plaque species, including MS.

CONCLUSIONS

Maternal use of xylitol gum did not result in statistically significant differences in the microbial plaque composition of 9- to 14-month-old infants.

Bridging the gap in caries management between research and practice through education: the Indiana University experience

Although dentistry recognizes that dental caries management encompasses more than restoring the consequences of the disease, caries risk assessment and management that go beyond traditional restorative care have not always had a strong and organized voice during clinical curriculum development and competency assessment in U.S. dental schools. This has resulted in confusion and great variability between the need for risk-based caries management and prevention and how practitioners apply these concepts in private and community settings. Dental education is in the unique position of being able to help bridge the gap to improve dissemination of new information and to enhance communication between research and the practice of dentistry to accelerate adoption of validated approaches for the diagnosis and management of dental caries. This paper presents one example of how a dental school totally revamped its approach to teaching cariology--from a few lectures scattered throughout the curriculum to a Cariology Management Program that is integrated into all four years of the curriculum, that includes both didactic and clinical components, and that emphasizes critical thinking and problem solving. From its inception, the program was centered on a competency requirement for graduation and the principles of evidence-based practice. The process, competency, and initial programmatic outcomes assessment measures are discussed. Barriers encountered are briefly reviewed from the following perspectives: dental school structure, faculty support/calibration, students, reimbursement, and standard of care/public expectations.

Erosive tooth wear: diagnosis, risk factors and prevention

PURPOSE

To provide an overview on diagnosis, risk factors and prevention of erosive tooth wear, which is becoming an increasingly important factor when considering the long- term health of the dentition.

RESULTS

Awareness of dental erosion by the public is still not widespread due to the cryptic nature of this slowly progressing condition. Smooth silky-glazed appearance with the absence of perikymata and intact enamel along the gingival margin, with cupping and grooving on occlusal surfaces are some typical signs of enamel erosion. In later stages, it is sometimes difficult to distinguish between the influences of erosion, attrition or abrasion during a clinical examination. Biological, behavioral and chemical factors all come into play, which over time, may either wear away the tooth surface, or potentially protect it. In order to assess the risk factors, patient should record their dietary intake for a distinct period of time. Based on these analyses, an individually tailored preventive program may be suggested to patients. It may comprise dietary advice, optimization of fluoride regimes, stimulation of salivary flow rate, use of buffering medicaments and particular motivation for non-destructive tooth brushing habits. The frequent use of fluoride gel and fluoride mouthrinse in addition to fluoride toothpaste offers the opportunity to minimize abrasion of tooth substance.

A screening test for unstimulated salivary flow measurement

It is well established that saliva is an important factor for the health of both soft and hard tissues in the oral cavity. This study determined: 1) the correlation between unstimulated salivary flow assessed using the Modified Schirmer tear strip Test (MST), with gravimetric and volumetric measurements and 2) the MST value that would allow the most reliable identification of patients with severe (<0.1 ml/minute) and moderate (<0.2 ml/minute) hyposalivation. A retrospective clinical study was conducted using data from 90 patients seen at the Indiana University School of Dentistry. All patients had a sample of unstimulated whole saliva collected by drooling for five minutes for volumetric/gravimetric assessment, followed by placement of the Schirmer strip in the floor of the mouth for three minutes (MST). Results showed a non-linear association between the MST and volumetric/gravimetric methods, with moderate Spearman correlation coefficients (0.67-0.71). Analysis of ROC-curves suggests that a cutoff screening value of 25 mm/three minutes provides high sensitivity (77%) and positive predictive value (71%) without significantly affecting specificity (80%). In conclusion, this study supports use of the MST test as a screening tool for hyposalivation.

The Role of Diet in the Aetiology of Dental Erosion

Acids of intrinsic and extrinsic origin are thought to be the main etiologic factors for dental erosion. There is evidence that acidic foodstuffs and beverages play a role in the development of erosion. However, the pH of a dietary substance alone is not predictive of its potential to cause erosion as other factors modify the erosive process. These factors are chemical (pKa values, adhesion and chelating properties, calcium, phosphate and fluoride content), behavioural (eating and drinking habits, life style, excessive consumption of acids) and biological (flow rate, buffering capacity, composition of saliva, pellicle formation, tooth composition, dental and soft tissue anatomy). The interplay between erosion and abrasion (specially oral hygiene practices) may be the main driver leading to the clinical manifestation of this disorder. Recommendations for patients at risk for dental erosion such as reducing acid exposure by reducing the frequency and contact of acids will be discussed.

Clinical applications and outcomes of using indicators of risk in caries management

The aim of this review was to systematically assess clinical evidence in the literature to determine the predictive validity of currently available multivariate caries risk-assessment strategies (including environmental, sociodemographic, behavioral, microbiological, dietary/nutritional, and/or salivary risk factors) in: 1) primary teeth; 2) coronal surfaces of permanent teeth; and 3) root surfaces of permanent teeth. We identified 1,249 articles in the search, and selected 169 for full review. Inclusion and exclusion criteria were established prior to commencement of the literature search. Papers that conformed to these criteria were included (n = 15 for primary teeth; n = 22 for permanent teeth; and n = 6 for root surfaces), and 126 papers were excluded. Included articles were grouped by study design as: longitudinal, retrospective, and cross-sectional. The predictive validity of the models reviewed depended strongly on the caries prevalence and characteristics of the population for which they were designed. In many instances, the use of a single predictor gave equally good results as the use of a combination of predictors. Previous caries experience was an important predictor for all tooth types.

A comparison of the erosive potential of different beverages in primary and permanent teeth using an in vitro model

The aim of this study was to compare the erosive potential of different beverages and foodstuffs in primary and permanent teeth. Sixty primary and 60 permanent human teeth were immersed for 3 min in the solution under study (5 teeth per treatment group). Surface microhardness was measured before and after exposure. Initial (baseline) surface microhardness was lower for primary teeth than for permanent teeth. In both primary and permanent teeth, Sprite showed the highest decrease in surface microhardness, whereas yogurt showed an increase in surface microhardness in the primary teeth. Overall decrease was 27.2 +/- 17.5 KHN (mean +/- SD) for primary and 25.9 +/- 15.6 KHN for permanent teeth. The comparison of the erosive susceptibility in this in vitro model showed that primary teeth were not more susceptible to erosion compared to permanent teeth.

Protective effect of milk against in vitro caries

Additions of milk solids to laboratory "cakes" made of sucrose and starch reduced in vitro (Orofax) "caries" and the dissolution of granular enamel, but increased the amounts of fermentation acids produced. Withdrawal of the milk component of ice cream, yogurt, and chocolate milk resulted in increased Orofax "caries".