Non-cavitated Enamel Lesions Research Articles

Surface porosity of enamel white spot lesions and penetration of fluorapatite nanocrystals into their subsurface: proof-of-concept study

ObjectivesIn this study, we used atomic force microscopy (AFM) to quantify the size of surface pore apertures of enamel white spot lesions and then demonstrated the penetration of fluorapatite nanocrystals (nFA) into the subsurface of these lesions. MethodsFor the porosity study, enamel lesions were created on three sound human teeth using a demineralizing gel for 8 days. The interface between sound enamel and the artificial lesion was analyzed by AFM. To visualize the penetration of nFA tagged with a calcium-binding fluorophore (Fluo-4) into the subsurface of white spot lesions, we used two-photon microscopy. Sixteen extracted human teeth with either active, natural, or in vitro-created carious lesions in enamel were randomly divided into three groups. The teeth were treated for 2 min with either a suspension of tagged nFA crystals, Fluo-4 alone, or deionized water, and left for 30 min before being washed with distilled water and examined microscopically. ResultsA greater concentration of surface pores with larger areas was observed on the in vitro demineralized enamel (29 % of pores greater than 1.0 µm2) when compared with the adjacent sound enamel (8 % of pores greater than 1.0 µm2) (p=0.012, Fisher exact test). In vitro and natural lesions treated with tagged nFA showed fluorescence at depths ranging from 50 to 170 µm, demonstrating penetration of the nFA into the lesion subsurface. The lesions treated with Fluo-4 alone with no crystals showed mostly surface fluorescence (restricted to the outer 25 µm), while those treated with deionized water showed minimal (restricted to the outer 20 µm) to no fluorescence. ConclusionWe have demonstrated the use of AFM to quantify the surface pore apertures and two-photon microscopy to visualize nFA crystals in the subsurface of non-cavitated enamel lesions. Clinical SignificanceThe restoration of the subsurface of non-cavitated caries lesions is a clinical challenge. This study demonstrated that a 2 min application of nFA could penetrate through the surface apertures of non-cavitated enamel lesions into their subsurface.

Effect of N-Acetylcysteine on initial Carious Enamel Lesions in primary teeth: an In-vitro study

BackgroundDental caries initiates with non-cavitated enamel lesions as the first stage. The cariogenic potential of N-Acetylcysteine (NAC) may be due to its usage frequency and form. This study aimed to evaluate the impact of exposure time of NAC on initial enamel caries-like lesions in primary teeth by assessing the morphological alteration using a scanning electron microscope (SEM) and mineral content using energy dispersive x-ray spectroscopy (EDX).MethodsForty primary incisor teeth were randomly divided into 4 groups S, S1, S2, and S3 (10 specimens/group). Teeth crowns were cut from their roots and inserted into an acrylic mold with its buccal surface directed upward. Centrally isolated enamel window (2 × 2 mm) on the tooth was done. Ten specimens were selected to evaluate normal enamel while the remaining thirty specimens were immersed in demineralizing solution for 96 h to produce enamel caries-like lesions. PH cycling was performed by immersing each tooth sample in 20 mL of demineralizing solution for 3 h then, preserved for the remaining day hours in 10 ml of artificial saliva interspersed with treatments applications with 10 ml NAC for 10 min twice a day for one- or three-months different treatment modalities. Thermocycling was done for all specimens then they were subjected to SEM and EDX analysis. ANOVA and Bonferroni post hoc tests were utilized in data analysis.ResultsIn teeth treated by NAC for 3 months (group-S3), SEM images showed severe loss of enamel architecture with large NAC deposits detected. A meaningful difference was observed among different groups concerning calcium, phosphorus, fluoride, ca/P ratio, carbon, nitrogen, and oxygen contents (P < 0.05).ConclusionNAC had a detrimental impact on enamel caries-like lesions in human primary teeth.

Resin Infiltration of Non-Cavitated Enamel Lesions in Paediatric Dentistry: A Narrative Review.

The resin infiltration (RI) technique was introduced as one of the minimal intervention dentistry strategies in addressing dental caries among the paediatric population. This technique used the low-viscosity resin monomer to infiltrate the non-cavitated carious lesion and other developmental enamel porosities, thus allowing the conservation of the tooth structure. This narrative review aims to explore the value of RI in Paediatric Dentistry. Through our search of the literature, the development of the material, their clinical applications and shortcomings, as well as the innovation that has been carried out to improve the current RI, were discussed. There are number of high-level evidence supporting the use of RI in arresting non-cavitated proximal caries lesions in primary and permanent teeth, but its efficacy in managing anterior white spot lesions is still unclear. Limited penetration depth, not radiopaque and questionable long-term colour and material stability were among the limitation of the material. Various laboratory-based studies have been conducted to improve the current properties of RI. Nevertheless, RI has emerged as one of the important micro-invasive techniques in addressing non-cavitated and anterior white-spot enamel lesions in children and adolescents with great success.

Efficacy of 1.23% acidulated phosphate fluoride gel on non-cavitated enamel lesions: a randomized clinical trial

A randomized controlled parallel clinical trial was conducted to evaluate the efficacy of the association of 1.23% topical professional acidulated phosphate fluoride (APF) gel with oral hygiene and dietary instructions on the arrest of active non-cavitated lesions in permanent, mixed, and temporary dentition in children between 3 and 12 years of age. Ninety-eight caries-active children were randomly divided into two groups: a fluoride gel group (n = 49) and a non-fluoridated gel group (n = 49). Each group received up to eight weekly applications of gel, weekly professional toothbrushing with oral hygiene instructions and dietary counselling. Caries lesions were assessed qualitatively through visual-tactile criteria performed in three stages: initial, intermediate, and final. Regression models were applied to identify risk indicators for caries control. Between-group comparison regarding the time taken to arrest the lesions was performed using Chi-squared and Fisher's exact tests. Seventeen children did not receive the allocated intervention, and one was lost to follow-up (n = 80). There was no difference between the control and placebo groups regarding the time to the arrest of the lesion (p >.05). The treatments showed similar results without significant statistical difference (p = 0.33; 95%CI: 0.32-1.48). No adverse effects were observed. It can be concluded that no additional effect of the association of 1.23% APF gel with oral hygiene using fluoride dentifrice and dietary instructions on the arrest of active non-cavitated lesions could be established. We can also confirm the importance of toothbrushing frequency and, consequently, the visible plaque reduction in the control of caries activity. RBR-37V5S3.

Radiographic pattern of underlying dentin lesions (ICDAS 4) in permanent teeth.

To assess the radiographic pattern of underlying dentine shadows (UDS) in the occlusal surfaces of permanent teeth. A total of 282 permanent posterior teeth pertaining to 91 individuals, 142 UDS and 140 non-cavitated enamel lesions (NCEL), were included for comparison. UDS was defined as shadows of discolored dentin visible through the enamel surface which may or may not show signs of localized enamel breakdown, classified as code 4 by the International Caries Detection and Assessment System group. Data collection included the application of a questionnaire, clinical examination, and bilateral bitewing radiographs. The risk for presenting radiolucency was estimated using logistic regression model with generalized estimating equations. Approximately 79% of UDS exhibited no radiolucency. The proportion of teeth exhibiting a radiolucency restricted to the enamel-dentin junction was 20.4% for UDS and 3.6% for NCEL (p < 0.001, chi-square test). UDS had a sixfold increased risk for exhibiting radiolucency compared with NCEL (OR = 5.78, 95% CI = 2.73-12.22, p < 0.001). Despite this finding, it is important to highlight that virtually all cases were located at the enamel-dentin junction, and only one tooth in each category of clinical status exhibited radiolucency at the outer one half of dentin. No tooth exhibited radiolucency reaching the deep dentin. The present study showed that UDS presented radiolucency in very few cases. The vast majority of lesions showed no radiolucency. Our findings suggest that only a small proportion of UDS would demand restorative treatment.

Effects of different resin sealing therapies on nanoleakage within artificial non-cavitated enamel lesions.

The aim of this study was to evaluate nanoleakage within the different lesion-sealing therapies applied to artificial non-cavitated enamel lesions. Thirty-two human anterior teeth were used. Artificial subsurface enamel lesions were produced on the labial surfaces of teeth. The specimens were then randomly divided into three groups (n=10): Group I- Clinpro Sealant application; Group II- ExciTE F adhesive resin application; and Group III- ICON resin infiltrant application. Each group was further divided into two subgroups: control and thermocycler. Nanoleakage was calculated by the digital image analysis software. In the control and thermocycled groups, there was no statistically significant difference between the Groups I, II, and III (p>0.05). The only significant leakage scores were obtained between the Group III control and thermocycler groups (p=0.027). ICON infiltrant can be used as an alternative to dental adhesives and fissure sealants in the sealing of initial non-cavitated enamel lesions. But the resin may become more affected by the water sorption than other resin materials over time. More studies are needed to evaluate long-term durability of resin infiltrants.

In vitro study to evaluate laser fluorescence device for monitoring the effect of aluminum gallium arsenide laser on noncavitated enamel lesions

Objective: The objective of this study was to evaluate the efficacy of laser fluorescence (LF)-based diagnostic device for monitoring the effect of aluminum gallium arsenide (Al Ga As) laser on noncavitated enamel lesions. Background: Dental caries is a reversible disease, and scope of reversing the carious lesion is increased if it is diagnosed before there is surface cavitation. Variegated remineralization strategies including remineralizing pastes and different lasers have been explored. The efficacy of this surface treatment requires a valid and a reliable assessment tool. LF is one such adjunct to traditional methods of caries detection. Materials and Methods: Twenty-five intact freshly extracted molars were sectioned mesiodistally so as to obtain fifty samples which were coated with nail varnish so that 3 mm × 3 mm of windows are created to maintain uniformity. All sample surfaces were evaluated with LF device so as to obtain the baseline values, these values served as control. All the samples were then acid etched by 30% phosphoric acid for 20 s to simulate surface demineralization. The LF device was used to record the values of demineralized samples. The surfaces of the teeth were then irradiated with Al Ga As laser of 3.5 W for 30 s. The LF device was then used to record the reading. Statistical Analysis Used: Statistical analysis was done using paired t-test to compare control and test groups and calculation of the mean. Results: The demineralized surfaces have recorded statistically significant LF values greater than the untreated control sample values. Post laser irradiation, there is fall of the LF values and these values are closer to that of control. Conclusion: Laser fluorescence can be used as a tool to detect demineralization in situ and monitor changes in enamel surface during demineralization and remineralization phases. Surface treatment with laser irradiation gave values closer to that of control and this does indicate that laser irradiation brings about surface alteration as evaluated by laser fluorescence.

Comparison of two visual methods for detecting caries among obese andnon-obese children

Objective: The study aimed to compare two visual methods for detecting caries among obese and non-obese children in Salvador, Brazil.Materials and methods: A cross-sectional study was conducted from 2011–2012, which evaluated 180 paediatric patients, 6–14 years old, girls and boys, categorized into two groups: obese and non-obese (healthy weight), according to the body mass index. For the evaluation of dental caries, the decayed, missing or filled teeth index (DMFT/dmft) and International Caries Detection and Assessment System II (ICDAS II) visual criteria were used.Results: The mean DMFT value was 0.98 in obese children and 0.57 in the non-obese children, without significant differences between groups (p = 0.206). The mean dmft value in the non-obese children (1.66) was higher than in obese children (0.95), with significant differences between groups (p = 0.021). According to ICDAS II criteria, there was a higher prevalence of non-cavitated enamel lesions (D1–3) in obese children (n = 156, 10.5%) compared to the non-obese children (n = 55, 1.9%), with significant differences between the groups (p < 0.001).Conclusions: The inclusion of non-cavitated lesions during the caries evaluation represents a challenge in diagnosis, which allows for control of this process before the evolution of these lesions to cavitation.

NON - OPERATIVE TREATMENT OF NON - CAVITATED APPROXIMAL CARIOUS LESIONS OF PERMANENT CHIDREN’S TEETH

SUMMARY Aim: To apply and follow up in clinical conditions the success rate of microinvasive technique of infiltration with low viscosity resin ICON® (DMG) of non cavitated approximal caries lesions of permanent children’s teeth for a period of one year. Material and methods: The study included 18 children aged 7-16 years. They were divided into two groups children with medium and high caries risk. The survey include 20 teeth with approximal non-cavitated enamel lesions up to the outer third of dentin (E1, E2, D1 – according to the manufacturer’s instructions of ICON®). The size of the lesions was determined using bitewing radiographs and the activity - by Papilla Bleeding Index. The clinical application of the infiltr+ant (ICON® Caries Infiltrant Proximal, DMG) was conducted according to the manufacturer’s instructions. Bitewing radiographs were made at 6 and 12 months after infiltration in order to evaluate the success of the method. A test of the difference between two relative proportions and alternative test for analysis of the results were used. Results: Our study confirm the hypothesis that this method of infiltration is equally successful for permanent teeth in patients with moderate caries risk as well as those at high caries risk. Conclusion: This study is the first survey regarding the success of the application of ICON® for treatment of noncavitated approximal carious lesions in permanent dentition of children in the country. Research in this direction should continue in order to increase the conviction that caries can be controlled and arrested in its earliest stages.

Optical coherence tomography as an auxiliary tool for the screening of radiation-related caries.

The aim of this study was to evaluate the morphological alterations of radiation-related caries using optical coherence tomography. Thirty-six extracted teeth from 11 patients who had undergone radiotherapy were sectioned in the sagittal axis in the center of the carious lesion, and 100 μm thick sections were obtained from each specimen. One sample from each tooth was investigated by an optical coherence tomography (OCT) system, and the results were compared with histological images from polarized light microscopy. In OCT dentin caries images, the demineralized area appeared as a white region, whereas the translucent zone appeared as a dark area, a similar pattern also seen in coronal caries. In noncavitated enamel lesions clinically observed as brown discoloration, the area of high porosity, and also the dark color, absorbs part of the light, resulting in a dark pattern. Finally, the involvement of dentin-enamel junction (DEJ) or cement-enamel junction (CEJ) could be clearly observed, when present and marked alterations along the CEJ could be noted, as junction continuity loss, gap formation, and mineral loss tissue. The OCT technique was able to characterize radiation-related caries, from a morphological point of view. Also demonstrated was its potential benefit for use in the clinical monitoring of radiation-related carious process.

Infiltration of Natural Caries Lesions in Relation to Their Activity Status and Acid Pretreatment in vitro

This study aimed at testing how active and inactive enamel caries lesions differ by their degree of resin infiltration, and whether the choice of acid pretreatment plays a crucial role. Four examiners assessed 104 human molars and premolars with noncavitated enamel lesions and classified them as ‘active’ or ‘inactive’ using the Nyvad criteria. Forty-five teeth were included in this study after independent unanimous lesion activity assessment. Lesions were cut perpendicularly into 2 halves. Each half lesion was pretreated with either 15% hydrochloric acid or 35% phosphoric acid. The lesions were infiltrated after staining with rhodamine isothiocyanate. Thin sections of 100 µm were prepared and the specimens were bleached with 30% hydrogen peroxide. The specimens were then counterstained with sodium fluorescein, subjected to confocal laser scanning microscopy and analyzed quantitatively. Outcome parameters were maximum and average infiltration depths as well as relative penetration depths and areas. In active lesions no significant difference of percentage maximum penetration depth and percentage average penetration depth between lesions pretreated with hydrochloric or phosphoric acid could be observed. In inactive lesions, however, phosphoric acid pretreatment resulted in significantly lower penetration compared to hydrochloric acid pretreatment. Surface conditioning with hydrochloric acid led to similar infiltration results in active and inactive lesions. Moreover, inactive lesions showed greater variability in all assessed infiltration parameters than did active lesions. In conclusion, caries lesion activity and acid pretreatment both influenced the infiltration. The use of phosphoric acid to increase permeability of the surface layer of active lesions should be further explored.

Preparation, characterization and in vitro efficacy of an acid-modified β-TCP material for dental hard-tissue remineralization

A blended material composed of beta-tricalcium phosphate (beta-TCP) and fumaric acid (FA) was prepared using a mechanochemical process. The structure and properties of the TCP-FA material was probed using particle size analysis, infrared, (31)P and (13)C solid-state nuclear magnetic resonance (NMR) spectroscopy, powder X-ray diffraction and calcium bioavailability. NMR studies showed that orthophosphate environments within beta-TCP remain largely unaffected in the presence of FA during mechanochemical processing; alternately, (13)C data indicated the carboxylic groups of FA are strongly affected during processing with beta-TCP. X-ray results reveal beta-TCP diffraction plane shifting with lattice contractions likely arising at the C(3) symmetry site. While milled beta-TCP (mTCP) produces a higher flux of bioavailable calcium relative to native beta-TCP, the mechanochemical conditioning of TCP-FA generates more than seven times the level of ionic calcium relative to mTCP. Collectively, the results from these studies indicate FA interfaces with calcium oxide polyhedra of the beta-TCP hexagonal crystal lattice, especially with the underbonded CaO(3) cluster manifested within the C(3) symmetry site of the beta-TCP motif. An in vitro remineralization/demineralization pH cycling dental model was then used to assess the potential of the TCP-FA material in reversing early stage non-cavitated enamel lesions. Characterization of the remineralization via surface and longitudinal microhardness measurements demonstrated that the TCP-FA material provides statistically superior remineralization relative to milled and native beta-TCP.

Comparative Fluorescence Spectroscopy Shows Differences in Noncavitated Enamel Lesions

The aim of this study was to compare emission spectra from noncavitated enamel caries with different degrees of discoloration under a wide range of excitation wavelengths. Freshly extracted human molars with white spot, light discolored and dark discolored brown spot enamel caries were selected (n = 4 each). Rectangular blocks (3.5 × 3.5 mm) were cut from the carious area and a corresponding sound area of the same tooth. Emission spectra were recorded from carious and the corresponding sound areas using a fluorescence spectrophotometer at excitation wavelengths from 360 nm up to 580 nm in steps of 20 nm. The specimens were submerged in water during measurement. The spectra were corrected and normalized to peak intensity for comparisons between spectra from sound and carious areas of each tooth. Excitation spectra were recorded for selected emission wavelengths that showed maximum intensity. Emission spectra of all types of carious lesions were shifted towards longer wavelengths (red shift) when compared to the spectra of the corresponding sound enamel. The red shift was highest for dark brown spot lesions and lowest for white spot lesions (p ≤ 0.001). Distinct fluorescence bands within 600–700 nm typical for porphyrin compounds were strongest for excitation wavelengths from 400 to 420 nm and present in most of the lesions investigated.