Lesion Arrest Research Articles

Evaluation of the Caries-Arresting Potential of Silver Diamine Fluoride Gel With Potassium Iodide Versus Sodium Fluoride Varnish: An Observational Study.

Introduction Silver diamine fluoride (SDF) with potassium iodide (KI) has emerged as a promising, aesthetic, non-invasive management by limiting the staining caused by SDF. However, no studies are comparing the caries-arresting potential of SDF gel with KI. The study aims to observe and evaluate the caries-arresting potential of SDF gel with KI compared to sodium fluoride (NaF) varnish. Materials and methods The present observational study was conducted with a split-mouth design. A total of 33 participants, in the age group of two to six years, with occlusal caries of the International Caries Detection and Assessment System (ICDAS) I and II involving both right and left upper or lower primary molar teeth, were included. SDF gel with KI and fluoride varnish (FV) was applied to the contralateral teeth on the same arch. Participants were recalled at 3, 6, 9, and 12-month intervals to monitor the progression or arrest of carious lesions. Result At the end of 12 months, 66.7% and 70.5% of the teeth showed arrest of caries with SDF gel with KI and FV, respectively. Intra-group analysis using the Friedman test shows significant differences in both groups across the timeline (p=0.001). Intergroup analysis using the Whitney U test reveals no significant difference in caries-arresting potential between the groups at various timelines (p=0.231). Conclusion There was no significant difference in arresting enamel caries of primary teeth between the use of 5% NaF and 38% SDF with KI. However, there was a significant difference within the group between the 3rd and 12th-month follow-up. Hence, the biannual application is recommended in both FV and SDF with KI.

Effectiveness of nanosilver fluoride and silver diamine fluoride in arresting early childhood caries: a randomized controlled clinical trial

BackgroundOne of the most prevalent health problems affecting children worldwide is untreated caries in primary teeth. Agents to arrest caries are used to manage untreated decay in children in disadvantaged communities. Nano Silver Fluoride (NSF) overcomes the staining problems of Silver Diamine Fluoride (SDF). This study compared the clinical cariostatic effect of NSF to 38% SDF for arresting caries lesions.MethodsThe study included 360 children younger than 4 years, with at least one active lesion, ICDAS score ≥ 3, recruited from nurseries in a rural area in Alexandria, Egypt, in 2022. They were randomly assigned to receive a single application of NSF at baseline, or two applications of SDF at baseline and after 6 months. The arrest of active carious lesions was assessed after 6 and 12 months using ICDAS criteria, and parents’ satisfaction with child appearance was also assessed. Chi-Square test was used to compare the groups and multi-level multiple logistic regression was used to assess the effect of the intervention on caries arrest at lesion level and binary logistic regression was used to assess the effect at patient level.Results1853 active lesions were included in children whose mean (SD) age was 42.3 (8.2) months. The arrest rate was significantly higher in the NSF than the SDF group at lesion level (78.4% and 65.0% at 6 months and 71.3% and 56.3% at 12 months, p < 0.001). In regression analysis, NSF had significantly higher odds of caries arrest than SDF at lesion level (at 6 months, AOR = 2.57, 95% CI: 1.55, 4.26 and at 12 month, AOR = 3.27, 95% CI: 1.89, 5.67). Parents of children receiving NSF had significantly greater satisfaction with their children’s dental appearance than those receiving SDF: (97.2% and 76.1%, respectively, p < 0.001).ConclusionNSF demonstrated greater effectiveness in arresting caries in preschool children without inducing black staining of teeth and with greater parental satisfaction than SDF. NSF can be an alternative to SDF in arresting caries especially in underprivileged communities.Trial registrationThe trial was registered in the clinicaltrials.gov registry (#NCT05255913)-16/02/2022.

Evaluation of rise in pH and oxygen release at the site of simulated external root resorption cavities using different oxygen-releasing biomaterials: An in vitro study.

External inflammatory root resorption has rapid onset and progresses aggressively. It leads to cementum loss, which allows communication between the infected pulp and the periodontium through the denuded dentinal tubules. Primary management strategy includes adequate chemomechanical debridement and lesion arrest for which maintaining alkaline pH and aerobic conditions is essential for healing and repair of the resorption defect. The aim of this study is to evaluate rise in pH and oxygen release at the site of simulated external root resorption cavities using different oxygen-releasing biomaterials. In 40 extracted single-rooted teeth access opening and chemomechanical debridement were done. Cavities simulating resorption defect are prepared on the roots. The samples are divided into four groups (n = 10) based on the biomaterial used. After placing the biomaterial, the root apices were sealed. Half of the samples from each group were tested for oxygen release using dissolved oxygen meter and the other half for rise in pH using pH meter at 7, 14, 21, and 28 days. The pH values were analyzed using Friedman 2-way analysis of variance (ANOVA) and Kruskal-Wallis test. Oxygen release was measured using the two-way and repeated-measures ANOVA. Calcium peroxide group showed the highest mean pH and oxygen release than other groups at any given point of time. Incorporating oxygen-releasing biomaterials such as calcium peroxide and perfluorodecalin into intracanal medicaments, such as calcium hydroxide, creates an alkaline and oxygen-enriched milieu in the periapical tissues.

Silver diamine fluoride with sodium fluoride varnish versus silver diamine fluoride in arresting early childhood caries: a 6-months follow up of a randomized field trial

BackgroundEarly childhood caries (ECC) is the most prevalent chronic health problem in young children, and it can be arrested using professionally applied fluoride such as Sodium fluoride (NaF) varnish and Silver Diamine Fluoride (SDF). This trial compared two interventions to arrest ECC lesions: 38% SDF combined with 5% NaF varnish versus 38% SDF and assessed whether the arrest rate was affected by baseline lesion severity measured by ICDAS.MethodsChildren aged ≤ 4 years from 4 nurseries in a rural area in Alexandria, Egypt joined the study in March 2022. They were included if they had at least one active carious lesion with ICDAS codes ≥ 3. They were randomized to receive either 38% SDF with 5% NaF varnish or 38% SDF alone. In both groups, the agents were applied at baseline and after 6 months on the caries lesions. NaF was additionally applied on all teeth in the oral cavity, and it was also applied after three months. The primary outcome was lesion arrest status after six months. Parents’ satisfaction with their children’s appearance was the secondary outcome. Pearson Chi-Square test was used for bivariate comparison and multi-level multiple logistic regression was used to assess the effect of the intervention on caries arrest controlling for confounders. The interaction between the intervention and baseline lesion severity (categorized into moderate and severe lesions) was assessed and the p value was calculated.ResultsThe study included 1606 lesions in 220 children, median (IQR) age = 48(9) months. The percentages of arrested lesions after the application of SDF + NaF and SDF only were 77.7% and 73.2% (p = 0.035). In multivariable analysis, SDF + NaF had significantly greater caries arrest effect than SDF alone (AOR = 2.12, p = 0.03) with significant difference (p = 0.03) between moderate (AOR = 4.10, p = 0.005) and advanced (AOR = 1.92, p = 0.08) lesions. Most parents were satisfied with their children’s appearance with no significant difference between groups (SDF + NaF = 84.5%, SDF = 78.18%, p = 0.23).ConclusionSDF + NaF had a higher arrest rate than SDF alone and this difference was significant in moderate but not advanced lesions. The findings have implications for the non-invasive management of ECC.Trial registrationThis trial was registered in the clinicaltrials.gov registry (#NCT05642494).

Factors that influence parental satisfaction with SDF treatment in healthy children and those with special healthcare needs

PurposeSilver diamine fluoride (SDF) is used as a caries management agent for the arrest of dentinal caries lesions. The purpose of this study was to evaluate the satisfaction with SDF treatment provided at a university pediatric dentistry clinic and to identify factors that may contribute to parental dissatisfaction.MethodsWe obtained retrospective data of children who received SDF treatment at our clinic from 1 February 2019 to 28 February 2021. Parents were contacted by phone to participate in a survey that evaluated their satisfaction with the treatment. Satisfaction was evaluated as a function of medical status, ease of treatment, outcome of SDF treatment, esthetics, and understanding of treatment goals and side effects using contingency tables and chi-square statistics.ResultsFrom 209 children who received SDF treatment, we were able to contact 91 parents by telephone, and 79 agreed to participate. Special healthcare needs (SHCN) patients were overrepresented in our sample, comprising 22.3% of all treated and 36.7% of participants. More than 90% were satisfied with the treatment, would do it again and would recommend it to others. Among the 49 children who complained of pain, SDF treatment resolved 82% of these complaints. In the subsample with follow-up in our clinic, approximately half of the treated teeth later received restorative treatment or were extracted, and the other half presented without further treatment. Some children received further treatment elsewhere. Parental dissatisfaction was related to staining of the anterior teeth (p = 0.04), the need for further treatment (p = 0.02) and a lesser understanding of side effects (p = 0.002).ConclusionMost parents were satisfied with SDF therapy as a dental treatment choice due to its easy application and desensitizing effects. Our findings indicate that parental understanding of the interim nature of the treatment and staining of the lesions is important to achieve parental satisfaction.

A Silver Fluoride Intervention to Improve Oral Health Trajectories of Young Indigenous Australians: Protocol for a Cluster Randomized Controlled Trial

Background Indigenous Australian children and adolescents experience profound levels of preventable dental disease. The application of silver fluoride (AgF) to active dental caries is a noninvasive alternative to traditional dental treatment approaches. There is particular utility among Indigenous children and young people with dental fear, who may not have access to timely or culturally safe dental service provisions. Objective The aims of this study are to: (1) assess levels of active dental caries among Indigenous children and young people in 6 Australian states and territories; (2) determine if an AgF intervention reduces levels of active disease over 12-24 months; (3) measure the impact of improved oral health on social and emotional well-being (SEWB) and oral health-related quality of life; and (4) calculate the cost-effectiveness of implementing such an initiative. Methods The study will use a 2-arm, parallel cluster randomized controlled trial design. Approximately 1140 Indigenous children and youth aged between 2 and 18 years will be recruited. Each state or territory will have 2 clusters. The intervention group will receive the AgF intervention at the start of the study, with the delayed intervention group receiving the AgF intervention 12 months after study commencement. The primary outcome will be the arrest of active carious lesions, with arrested caries defined as nonpenetration by a dental probe. Secondary outcomes will include SEWB, oral health-related quality of life, and dental anxiety, with covariates including dental behaviors (brushing and dental visits). Effectiveness measures for the economic evaluation will include the number of children and young people managed in primary oral health care without the need for specialist referral, changes in SEWB, the numbers and types of treatments provided, and caries increments. Results Participant recruitment will commence in May 2023. The first results are expected to be submitted for publication 1 year after a 24-month follow-up. Conclusions Our findings have the potential to change the way in which active dental disease among Indigenous children and young people can be managed through the inclusion of specifically tailored AgF applications to improve dental health and SEWB delivered by Indigenous health care workers. Desired impacts include cost savings on expensive dental treatments; improved SEWB, nutrition, social, and learning outcomes; and improved quality of life for both children and young people and their caregivers and the broader Indigenous community. The AgF application could be easily implemented into the training program of Indigenous health workers and yield critical information in the management armamentarium of health and well-being recommendations for Australia’s First Peoples. International Registered Report Identifier (IRRID) PRR1-10.2196/48558

Monitoring lesion activity on primary teeth with CP-OCT and SWIR reflectance imaging.

The purpose of this study was to use cross polarization optical coherence tomography (CP-OCT) and short wavelength infrared imaging (SWIR) reflectance imaging to monitor changes in the structure and activity of early occlusal caries on primary teeth over a period of 6 months during intervention with fluoride. Participants (n = 29) aged 6-10 each with two suspected active occlusal lesions on primary teeth completed the study. Fluoride varnish was applied to tooth surfaces every 3-months and participants were instructed to brush twice daily with a fluoride toothpaste. Images were acquired using CP-OCT every 3 months for 6 months. SWIR reflectance images were acquired during forced air-drying of the lesions for 30 s at 0 and 6-months. Most of the 42 lesions appeared initially active at baseline. Only 6 lesions appeared arrested at baseline based on the presence of a highly mineralized transparent surface layer (TSL) in CP-OCT images. At 6 months, 14 of the lesions appeared arrested including the 6 initially arrested lesions and the TSL thickness increased significantly (p < 0.0001). The mean lesion depth (Ld) and the integrated reflectivity over the lesion depth (ΔR) increased significantly (p < 0.05) after 6 months for the 42 lesions analyzed. SWIR reflectance images showed that there was a significantly higher (p < 0.05) delay before changes in intensity were measured for active lesions versus arrested lesions during lesion drying. CP-OCT was able to monitor changes in lesion structure and activity including the formation of a highly mineralized TSL indicative of lesion arrest during nonsurgical intervention. Time-resolved SWIR reflectance imaging also shows that there are differences in the dehydration kinetics between active and arrested lesions. This study demonstrates two independent imaging methods that can be used to monitor changes in lesion activity over time.

Active Surveillance of Root Caries in Vivo with CP-OCT.

The active surveillance of root caries lesions to monitor potential remineralization or decay progression is challenging for the clinician, due to unreliable diagnostic information. The conventional visual and tactile methods for assessing the lesion activity are not reliable, and the clinician is often unable to determine if the lesion is progressing or has been arrested. An important marker of an arrested lesion is a highly mineralized transparent surface zone (TSL) that forms when the mineral is deposited in the outer layer of the lesion. The purpose of this study was to determine if cross-polarization optical coherence tomography (CP-OCT) could be used to detect changes in the lesion severity and activity during active monitoring. In total, 18 subjects with 22 suspected active root caries lesions were evaluated using CP-OCT at the baseline, 3 months, and 6 months. All subjects were instructed to use a high fluoride dentifrice at the baseline. The results showed that CP-OCT was able to discriminate the active from the arrested lesions by identifying the presence of a TSL on arrested lesions. The results also indicated that the mean TSL thickness increased significantly (p < 0.05) for the nine lesion areas. In addition, CP-OCT was able to show the progression of demineralization, erosion, and changes in gingival contours in scanned areas. CP-OCT was valuable for monitoring the activity and severity of root caries lesions in vivo. CP-OCT can be used to assess the activity of root caries lesions at a single time point by detecting the presence of a TSL at the lesion surface indicative of the lesion arrest.

Assessment of the activity of secondary caries lesions with short-wavelength infrared, thermal, and optical coherence tomographic imaging.

Significance: Leakage in the interfaces between restorative materials and tooth structure allows for fluid and bacterial acid infiltration, causing restoration failure due to secondary caries. Dentists spend more time replacing composite restorations than placing new ones. Previous in vitro and in vivo studies on enamel and root surfaces using shortwave-infrared (SWIR) and thermal imaging during dehydration with forced air have been promising for assessing lesion activity. Aim: We hypothesized that SWIR reflectance and thermal imaging methods can be used to monitor the activity of secondary caries lesions around composite restorations. The objective of this study was to employ these methods to measure the rate of fluid loss from lesions during dehydration with forced air to assess lesion activity. Approach: Sixty-three extracted human teeth with total of 109 suspected secondary lesions were examined using SWIR and thermal imaging during dehydration. The thickness of the highly mineralized transparent surface layer (TSL) at lesion interfaces indicative of lesion activity was measured by optical coherence tomography (OCT). Micro-computed tomography (MicroCT) was used to further confirm lesion severity and structure. OCT and MicroCT measurements of lesion structure, depth, and severity were correlated with fluid loss rates measured with SWIR reflectance and thermal imaging. Results: TSL thickness measured with OCT correlated with both SWIR reflectance and thermal measurements of rates of fluid loss ( ). Increasing TSL thickness led to decreased permeability of lesions, potentially indicating full lesion arrest at . SWIR performed better than thermal imaging for secondary lesion activity assessment, although both methods performed best on smooth surface lesions. Conclusions: Nondestructive SWIR reflectance and OCT imaging methods are promising for clinically monitoring the activity of secondary caries lesions.

Chapter 9.4: Operative Treatment and Monitoring of Coronal Caries in Daily Practice.

After the caries lesion reaches a certain extent of tooth structure loss, a restoration is often needed to repair the defect. Operative interventions in cariology aim to aid biofilm removal and lesion arrest by cavity sealing, avoid pulpal damage, and restore form, function, and esthetics. There are no clear evidence-based parameters to determine the most appropriate treatment option for each clinical situation. Despite of this, direct composite resins have been the preferable restorative treatment. Scientific literature shows that composites and adhesive strategies play a minor role in treatment success. Patient-related risk factors (mainly those associated with lifestyle and health choices), in addition to the dentist's decision-making process, play a significant role in longevity of the restorations, which tend to fail for the same reasons that lead to the need for restoration (dental caries, tooth/restoration fracture, and esthetics). Therefore, monitoring old restorations in clinical service, even if those present clear signs of degradation, is possible and reasonable within the concept of minimal intervention in dentistry. Unnecessary reinterventions are harmful and costly to health systems, and the clinician's efforts must be directed to eliminating or reducing the etiological factors that can cause the restoration to fail. Thus, patient risk factors assessment is a crucial point in monitoring restorations. Clinician should - whenever possible - postpone operative reinterventions, monitoring the etiological factors that may compromise the restoration's longevity. Also, when operative reintervention is necessary, refurbishment, polishing, and repair should be prioritized over replacement.

Comparison of nano-silver fluoride, nano-hydroxyapatite and sodium fluoride varnishes in prevention and arrestment of initial carious lesions: a randomized controlled clinical trial

Comparison of nano-silver fluoride, nano-hydroxyapatite and sodium fluoride varnishes in prevention and arrestment of initial carious lesions: a randomized controlled clinical trial

Analysis of the transparent surface layer formed at the surfaces of arrested enamel caries lesions with tomographic imaging methods

BackgroundOptical coherence tomography (OCT) can acquire high-resolution images of lesion structure in vivo to assess lesion activity. The surface layers of arrested enamel caries lesions (ECLs) have a higher mineral content than the lesion body with a reduced porosity that inhibits the penetration of fluids into the lesion and appears with reduced reflectivity OCT. This study aimed to use microcomputed tomography (microCT) to measure the mineral content of the transparent surface layer (TSL) that appears on OCT images. MethodsOCT and microCT were used to measure the reflectivity and relative mineral density profiles of 20 bovine enamel samples that had simulated arrested ECLs, 44 extracted teeth with 17 proximal ECLs, 10 occlusal ECLs, and 17 lesions caused by fluorosis. TSL thickness (OCT), surface layer thickness (microCT), and the minimum and maximum densities of the TSLs were determined from matched OCT and microCT profiles. ResultsFor all samples, the TSL thickness measured with OCT was significantly less than the surface layer thickness measured with microCT (P < .05). Mean maximum mineral densities in the TSL were statistically similar to sound human enamel (P > .05) and significantly higher (P < .05) than the mean minimal mineral densities of the TSL. ConclusionsThe maximum mineral densities of the TSL measurable with OCT approach those of sound enamel suggesting that almost complete remineralization has occurred in the TSLs. This study provides further confirmation that the presence of a TSL in OCT images is a key indicator of lesion arrest.

The antibacterial effect of nanosilver fluoride in relation to caries activity in primary teeth: a protocol for a randomized controlled clinical trial

BackgroundMinimally invasive dentistry is a highly convenient and efficient method of managing caries in pediatric patients. Silver diamine fluoride (SDF) is commonly used to arrest active caries lesions. However, the associated black stain, possibility of soft tissue injury, and unpleasant taste often limit its use. Recently, nanosilver fluoride (NSF) emerged as a promising topical fluoride agent with potent cariostatic and antibacterial potentials. This novel anticaries agent has gained attention as an alternative to overcome the drawbacks of SDF in caries arrest.ObjectivesTo assess the antibacterial effect of NSF in relation to caries activity in dentin caries lesions, as well as to investigate the change in saliva bacterial levels in primary teeth in comparison to SDF after 1 and 3 months.Materials and methodsFifty children aged 4 to 6 years old with active dentin caries lesions (score 5 according to International Detection and Assessment System (ICDAS II) criteria) will be enrolled in the study. They will be equally and randomly allocated into 2 groups: a group receiving NSF and a control group receiving SDF treatment. Microbiological samples will be collected from the carious lesions and from unstimulated saliva at the baseline and at the 1 and 3 months’ follow-up appointments. Bacterial counts will be assessed using Mitis Salivarius agar (selective culture media for S. mutans) and Rogosa agar (selective culture media for lactobacilli), and the results will be expressed in colony-forming units. Data regarding the children’s oral health will be collected and their dmf index will be scored. The arrest of active carious lesions will be measured at the follow-up appointments according to ICDAS II criteria.ResultsThe relation between bacterial colony counts and lesion activity for both groups will be assessed, as well as the change in salivary bacterial counts. The collected data will be statistically evaluated and tabulated. This clinical trial has been registered on ClinicalTrials.gov in January 2022 (original version) with ID: NCT05221749.

In Vitro Study on the Influence of Silver Diamine Fluoride on the Adhesion Strength of Dental Restorative Materials

Silver diamine fluoride (SDF) has demonstrated its clinical success for years in the arrest of caries lesions; however, the influence it could have on the success of restorations after its application still remains unknown. The purpose of this research was to study the relationship between the use of SDF and the adhesive strength of the materials used in restorations made with glass ionomers and composite resin, as well as with different adhesive systems. A sample consisting of 240 teeth divided into eight groups with 30 teeth in each of them (n = 30) was used. In these groups, the use of restoration with composite resin and glass ionomer was compared using different adhesive systems, with and without prior application of SDF. Notable differences in adherence were observed among the different groups depending on the filling material. There is also a significant effect of tooth type on adhesion. We can conclude that there is a relationship between the use of SDF and the adhesion between the tooth and the restorative materials analyzed.

Effect of application time of 38% silver diamine fluoride solution on arresting early childhood caries in preschool children: a randomised double-blinded controlled trial protocol

BackgroundTo study the caries lesion activity response to topical 38% silver diamine fluoride (SDF) therapy with increasing treatment application time.Methods/designThe design is a stratified-randomised, double-blind, active-controlled, parallel-group clinical trial with nine treatment arms. The trial will involve recruiting at least 414 3- to 5-year-old kindergarten children with caries, who will receive approximately 0.004 mL of 38% SDF (the typical amount applied per the manufacturer’s instructions) to treat each caries lesion. The children will be stratified by caries status, randomised by blocks, and allocated to nine groups of SDF application times: 3, 5, 10, 15, 30, 45, 60, 120, and 180 s. The outcome measure is caries lesion activity (active/arrest) at the tooth-surface level at 6 months post-initial treatment. A calibrated dentist will conduct the blinded clinical examinations at baseline and at the 6-month follow-up. In addition, the parents will be surveyed to examine the effects of the moderating variables, such as oral hygiene, on caries lesion activity. The hypothesis is that a monotonically increasing trend can be found between the SDF application time and the proportion of caries lesions that are arrested. The Cochran-Armitage test for trends in proportions, corrected for clustering within children, will be used to determine the relationship between the exposure to SDF (the SDF application time) and the response (proportion of lesions arrested) in children, taking into consideration the effect of the moderating variables as well as the nesting of multiple caries lesions within an individual child. An EC 80 analysis (an 80% maximal concentration) will be used to determine the exposure (the SDF application time) for 80% caries lesion arrest. Bootstrap methods will be used for clustered data and will be resampled by clustering to determine the 95% confidence interval.DiscussionThis study will help with determining the optimal application time for SDF treatment. It will provide an evidence-based protocol for the use of SDF to arrest tooth decay in the primary teeth of young children. The results will inform an evidence-based SDF protocol to arrest caries, which affects 573 million children with tooth decay worldwide.Trial registrationClinicalTrials.gov NCT04655430. Registered on 7th December 2020.

Use of SWIR dehydration and OCT to assess the complete arrest of simulated incipient caries lesions.

Previous studies have shown that optical coherence tomography (OCT) can be used to show the formation of a transparent surface zone on caries lesions indicative of remineralization. Studies have also shown that monitoring changes in the diffuse reflectivity of caries lesions during drying with air can be used to assess lesion activity and that the largest changes occur at SWIR wavelengths coincident with high water absorption at 1450 and 1950 nm. The purpose of this study was to determine when remineralization has occurred by monitoring changes in SWIR reflectance measurements and OCT images of simulated lesions over an extended time period during exposure to a remineralization solution. Eight bovine enamel surfaces each with two treatment windows were exposed to a pH cycling regimen to produce simulated lesions 50-100 μm deep. OCT at 1310 nm was used to image the samples at each time point. An extended range tungsten halogen lamp with a 1450 nm band pass filter and a broadband amplified spontaneous emission source centered near the peak of the water-absorption band at 1950 nm were used as light sources. An extended range InGaAs camera (1000-2340 nm) was used to acquire reflected light images as the samples were dried with air. After 32 days of exposure to the remineralization solution there were no further changes to the samples suggesting they had been completely arrested.

Dynamic SWIR imaging near the 1950-nm water absorption band for caries lesion diagnosis.

.Significance: It is not sufficient to detect caries lesions on tooth surfaces; it is also necessary to measure the activity of the lesions to determine if intervention is needed. Changes in the reflectivity of lesion areas during dehydration with forced air at short wavelength infrared (SWIR) wavelengths can be used to assess lesion activity since these changes represent the evaporation dynamics of water from the lesion.Aim: The aim of this study is to develop new optical methods for assessing lesion activity on tooth surfaces utilizing the strong water absorption band near 1950-nm.Approach: The time-resolved reflectivity of 20 active and arrested caries lesions on the surfaces of human extracted teeth was monitored at 1300 to 2000 nm using broadband light sources and an extended range InGaAs camera during drying with air.Results: Multiple parameters representing the rate of change of the lesion reflectivity correlated with the presence of a highly mineralized outer surface zone indicative of lesion arrest measured with x-ray microtomography (microCT). Performance at 1950-nm was higher than for other wavelengths.Conclusions: This study demonstrates that SWIR imaging near 1950-nm has great potential for the assessment of lesion activity.

Evaluating the effectiveness of fluoride varnish in preventing caries amongst Long‐Term Care Facility Residents

To evaluate the effectiveness of professionally applied fluoride varnish on the incidence of dental caries amongst older adults resident in LTCFs in Northern Ireland. The oral health status of older adults within Long-Term Care Facilities (LTCFs) is significantly worse than their community living peers. Whilst evidence suggests an important role for fluoride varnish in preventing caries in this population, very few studies have evaluated this intervention. A quality improvement project was undertaken with dentate residents (n=190) in nine LTCFs who had fluoride varnish applied by Dental Care Professionals on two separate occasions during a 12-month period (intervention group). Nine LTCFs were chosen as matched controls (control group) with comparable numbers of residents of similar medical status (n=217). For the intervention group, oral hygiene training was also provided for the care home staff. A total of 407 patients (n=271 female) were included in the analyses (mean age [SD]: 84.1 [6.6] years). After 12months, the intervention group recorded a significant reduction in mean number of carious teeth (mean [95% CI]: -0.85 [-1.12, -0.58]; P<.001). Patients in the control group had significant increases in the mean number of carious teeth (mean [95% CI]: 0.21 [0.05, 0.37]; P=.012), mean plaque score (mean [95% CI]: 1.16 [0.28, 2.04]; P=.010) and mean DMFT score (mean [95% CI]: 0.13 [0.04, 0.22]; P=.004). This study demonstrates the potential role of fluoride varnish in combination with oral hygiene training for staff in the prevention and arrest of carious lesions among older adults in LTCFs.

O diamino fluoreto de prata no controle da cárie na primeira infância durante a pandemia da COVID-19

Objetivo: Abordar aspectos de interesse clínico relacionados ao uso do diamino fluoreto de prata (DFP) no controle da cárie na primeira infância (CPI) durante a pandemia da COVID-19. Métodos: A busca para revisão de literatura foi executada na base de dados PubMed. Os descritores foram escolhidos pela importância na delimitação do tema e a síntese da literatura foi realizada de acordo com os tópicos: (1) efetividade clínica, indicações e limites do DFP e (2) uso clínico do DFP no contexto da COVID-19. Resultados: A pandemia da COVID-19 afeta todos os setores da sociedade, e, especialmente para o odontopediatra, impõe desafios em um cenário de difícil tomada de decisão e passível de contaminação. O tratamento da doença cárie com DFP ganha uma conotação importante pela sua eficácia na paralização da atividade de cárie, prevenção de novas lesões, segurança, facilidade de uso e baixo custo. Além disso, o DFP é considerado uma terapia minimamente invasiva que dispensa uso de instrumentos rotatórios (que tem alto potencial contaminante via dispersão de aerossol), e reduz complicações como pulpite e perda dentária e, portanto, o número de consultas. O DFP é também uma opção clínica na qual há uma maior aceitação comportamental pela criança. Como ponto negativo, o DFP pode causar insatisfação estética devido ao escurecimento da superfície afetada. Conclusão: O controle de lesões de cárie em crianças com CPI utilizando DFP, durante a pandemia da COVID-19, é uma opção eficaz, barata, de fácil aplicação e que oferece menos riscos de contaminação pelo coronavírus.

Infrared imaging confirms the role of the transparent surface zone in arresting dental caries.

Several studies have demonstrated the potential of short wavelength infrared (SWIR) reflectance, thermal imaging and optical coherence tomography for the nondestructive assessment of the activity of caries lesions. The purpose of this study was to test the hypothesis that the activity of arrested caries lesions on the coronal surfaces of extracted teeth would be changed by reducing the thickness of the highly mineralized transparent surface layer, which was measured using polarization sensitive optical coherence tomography (PS-OCT). The lesion activity was assessed using SWIR reflectance and thermal imaging during forced air drying of the lesion before and after mechanical removal of a surface layer ~ 50-μm thick covering the lesion. Both the intensity change in SWIR reflectance images at 1500-1750-nm wavelengths after drying the lesions and the change in thermal emission measured with a thermal camera at 8-13-μm wavelengths increased significantly (P<0.05) after reducing the thickness of the mineralized surface layer in the lesions indicating the permeability of the lesion to fluids increased. These results provide further evidence that the presence of a highly mineralized outer surface layer is a key indicator of lesion arrest.