Incipient Lesions Research Articles

Effectiveness of Remineralization Treatments on Incipient Lesions: A Controlled Clinical Trial

Twenty-nine subjects with a total of 218 teeth with (Diagnodent Pen) DD values > 0 were included. Subjects were divided randomly into four groups: Control [7 subjects, 54 teeth]; 5% Sodium fluoride varnish (FL-V) [8 subjects, 59 teeth]; Chlorhexidine varnish: 1% chlorhexidine diacetate and 1% thymol (CHX-V) [7 subjects, 54 teeth], and 10% Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) [7 subjects, 51 teeth]. All patients used fluoride-containing toothpaste, and the control group received fluoride gel every 3 months during the first 6 months.

Impact of toothbrushing frequency and toothpaste fluoride/abrasivity levels on incipient artificial caries lesion abrasion

ObjectivesTo investigate the interplay among brushing frequency, dentifrice slurry abrasivity, and fluoride content on the surface loss (SL) of incipient enamel caries-like lesions. MethodsLesions were created in 96 bovine enamel specimens (5 × 5 mm) using methylcellulose acid gel. Specimens were randomly allocated to 12 groups (n = 8), resulting from the association of three experimental factors: (1) slurry abrasive level [low: REA = 4/RDA = 69 and high: REA = 7/RDA = 208], (2) fluoride concentration [275 and 1250 ppm F as NaF], and (3) brushing frequency [1, 2 and 3× daily]. Specimens were kept in artificial saliva in between brushings and overnight. SL was determined by optical profilometry after lesion creation, 1, 3, 5, and 7 days. Data was analyzed with repeated measures ANOVA and Tukey’s tests (α = 0.05). ResultsHigh abrasive slurry caused significantly more SL than low with 275 ppm (p < 0.001) but not with 1250 ppm fluoride (p = 0.34). Fluoride at 275 ppm had significantly more SL than 1250 ppm with high abrasive slurry after 7 days (p = 0.008). Brushing 1×/day had significantly less SL than 3×/day after 7 days with high abrasive slurry (p = 0.016), especially in the 275 ppm fluoride groups. ConclusionsHigher fluoride concentration increased protection against the deleterious effect of high abrasive slurry. SL was higher if brushing was performed more than twice daily especially in low fluoride groups. Clinical significanceHighly abrasive toothpaste formulations might cause more surface wear to incipient caries lesions, especially at higher brushing frequencies. Increasing the fluoride content may be beneficial at these circumstances.

Effectiveness of sealants on incipient cavitaded lesions

Effectiveness of sealants on incipient cavitaded lesions

In-vitro subsurface remineralisation of artificial enamel white spot lesions pre-treated with chitosan

ObjectiveTo test the null hypothesis that chitosan application has no impact on the remineralisation of artificial incipient enamel white spot lesions (WSLs). Methods66 artificial enamel WSLs were assigned to 6 experimental groups (n=11): (1) bioactive glass slurry, (2) bioactive glass containing polyacrylic acid (BG+PAA) slurry, (3) chitosan pre-treated WSLs with BG slurry (CS-BG), (4) chitosan pre-treated WSLs with BG+PAA slurry (CS-BG+PAA), (5) remineralisation solution (RS) and (6) de-ionised water (negative control, NC). Surface and cross-sectional Raman intensity mapping (960cm−1) were performed on 5 samples/group to assess mineral content. Raman spectroscopy and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were used to identify the type of newly formed minerals. Surface and cross-sectional Knoop microhardness were implemented to evaluate the mechanical properties after remineralisation. Surface morphologies and Ca/P ratio were observed using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX). Data were statistically analysed using one-way ANOVA with Tukey’s test. ResultsBG+PAA, CS-BG, RS presented significantly higher mineral regain compared to NC on lesion surfaces, while CS-BG+PAA had higher subsurface mineral content. Newly mineralised crystals consist of type-B hydroxycarbonate apatite. CS-BG+PAA showed the greatest hardness recovery, followed by CS-BG, both significantly higher than other groups. SEM observations showed altered surface morphologies in all experimental groups except NC post-treatment. EDX suggested a higher content of carbon, oxygen and silicon in the precipitations in CS-BG+PAA group. There was no significant difference between each group in terms of Ca/P ratio. SignificanceThe null hypothesis was rejected. Chitosan pre-treatment enhanced WSL remineralisation with either BG only or with BG-PAA complexes. A further investigation using dynamic remineralisation/demineralisation system is required with regards to clinical application.

MT4-MMP deficiency increases patrolling monocyte recruitment to early lesions and accelerates atherosclerosis

Matrix metalloproteinases are involved in vascular remodeling. Little is known about their immune regulatory role in atherosclerosis. Here we show that mice deficient for MT4-MMP have increased adherence of macrophages to inflamed peritonea, and larger lipid deposits and macrophage burden in atherosclerotic plaques. We also demonstrate that MT4-MMP deficiency results in higher numbers of patrolling monocytes crawling and adhered to inflamed endothelia, and the accumulation of Mafb+ apoptosis inhibitor of macrophage (AIM)+ macrophages at incipient atherosclerotic lesions in mice. Functionally, MT4-MMP-null Mafb+AIM+ peritoneal macrophages express higher AIM and scavenger receptor CD36, are more resistant to apoptosis, and bind acLDL avidly, all of which contribute to atherosclerosis. CCR5 inhibition alleviates these effects by hindering the enhanced recruitment of MT4-MMP-null patrolling monocytes to early atherosclerotic lesions, thus blocking Mafb+AIM+ macrophage accumulation and atherosclerosis acceleration. Our results suggest that MT4-MMP targeting may constitute a novel strategy to boost patrolling monocyte activity in early inflammation.

Effect of resin infiltration and microabrasion on the microhardness, surface roughness and morphology of incipient carious lesions

Objective: The effects of resin infiltration and microabrasion on incipient carious lesions by surface microhardness, roughness and morphological assessments, and resistance to further acid attack of treated lesions were evaluated.Material and methods: Eighty artificially-induced incipient lesions were randomly divided into five groups (n = 16): resin infiltration with an adhesive resin (Excite F, Ivoclar Vivadent, Schaan, Liechtenstein), resin infiltration with a resin infiltrant (Icon, DMG, Hamburg, Germany), microabrasion without polishing (Opalustre, Ultradent, South Jordan, UT, USA), microabrasion with polishing (Opalustre, Ultradent, Diamond Excel, FGM, Joinville, SC, Brazil), and distilled water (control group). All specimens were exposed to demineralization for another 10 d. Microhardness, roughness and morphological assessments were done at baseline, following initial demineralization, treatment and further demineralization. Data were analysed by the Kruskal–Wallis, Friedman’s and Bonferroni tests (p < .05).Results: Enamel lesions treated with resin infiltrant and microabrasion demonstrated similar hardness values, with a nonsignificant difference compared with sound enamel. Resin infiltration demonstrated lower roughness values than those of microabrasion, and the values did not reach the values of sound enamel. Further demineralization for 10 d did not affect the hardness but increased the roughness of infiltrated and microabraded enamel surfaces. Polishing did not influence the roughness of microabraded enamel surfaces. After resin infiltration, porosities on enamel were sealed completely. The surface structure was similar to that of the enamel conditioning pattern for microabraded enamel lesions.Conclusions: Within the limitations of this study, the icon infiltration and microabrasion technique appeared to be effective for improving microhardness. Icon appeared to provide reduced roughness, although not equal to sound enamel. Further research is needed to elucidate their clinical relevance.

Effect of Two Remineralizing Agents on Initial Caries-like Lesions in Young Permanent Teeth: An in Vitro Study

To compare the effect of nano-hydroxyapatite (9000 ppm F) and casein phosphopeptide-amorphous calcium phosphate fluoride (900 ppm F) pastes on initial enamel carious lesions of young permanent teeth. Sixty extracted young premolars with a standardized window on enamel were immersed in a demineralizing solution for 48 hours to produce subsurface enamel lesions. They were divided into three groups according to remineralizing agents (n = 20) group I: nano-hydroxyapatite paste; group II: casein phosphopeptide-amorphous calcium phosphate fluoride paste; and group III: control (without an agent). The enamel surface microhardness (SMH) was measured at baseline, after the incipient enamel lesion, and after treatment. Additional twenty young premolars were selected and prepared as mentioned above for surface morphology evaluation by scanning electron microscope (SEM). No significant difference was found in mean surface microhardness in teeth treated with nano-hydroxyapatite paste and those treated with casein phosphopeptide-amorphous calcium phosphate fluoride p = 0.26. SEM showed improvement in surface defects of demineralized enamel in the two test groups. Nano-hydroxyapatite and casein phosphopeptide-amorphous calcium phosphate fluoride pastes were effec -tive in rehardening the initial enamel caries lesions in young permanent teeth. The best strategy for caries management is to focus on the methods of improving the reminer-alization process with the aid of the remineralizing agents. The current study compared the remineralizing effect of two remineralizing agents. Within the limitations of the study, both remineralizing agents were effective for remineralization of early caries-like lesions.

Performance of Different Methods for Detection of Incipient Occlusal Caries Lesions: An In Vitro Study.

The aim of this in vitro study was to evaluate the diagnostic performance of visual inspection (VI), laser fluorescence (LF pen), fluorescence camera (FC), and alternating current impedance spectroscopy technique (ACIST) for detection of incipient occlusal caries lesions. Histology was used as the gold standard to determine the interexaminer reliability of the methods, among three examiners with different levels of experiences (Examiner 1: 5 years; examiner 2: 10 years; and examiner 3: 25 years). One hundred two molar teeth were selected. The occlusal surfaces of teeth were evaluated with VI, LF pen, FC, and ACIST devices independently by three examiners. Diagnostic performances of methods were evaluated with binormal receiver-operating characteristics analysis. Interexaminer agreement of detection methods was assessed using Cohen's kappa coefficient values (p < 0.001). Incipient enamel lesions were determined more successfully with VI by all examiners. All detection methods were presented with statistically acceptable interexaminer agreement (p < 0.001). For D2 and D3 thresholds, FC for examiner 1, VI for examiner 2, and both VI and FC for examiner 3 demonstrated statistically high sensitivity and specificity (p < 0.05). It can be concluded that diagnostic performance of the methods was insufficient for detecting incipient occlusal caries lesions by itself. Performance can be improved by using them with VI as a traditional caries detection method.

The Use of Pit and Fissure Sealants-A Literature Review.

This paper reviews the literature and discusses the latest updates on the use of pit and fissure sealants. It demonstrates the effectiveness of pit and fissure sealants in preventing caries and the management of early carious lesions. It compares the use of different sealant materials and their indications. It describes the application technique for sealants. It also reviews the cost-effectiveness of sealants as a preventive strategy. From this review and after the discussion of recently published studies on pit and fissure sealants, it is evident that sealants are effective in caries prevention and in preventing the progression of incipient lesions. It is therefore recommended that pit and fissure sealant be applied to high-caries-risk children for optimum cost-effectiveness. It is a highly sensitive technique that needs optimum isolation, cleaning of the tooth surface, etching, and the application of a thin bonding layer for maximum benefit. Recall and repair, when needed, are important to maximize the effectiveness of such sealant use.

Th-17 cytokines are associated with severity of Trypanosoma cruzi chronic infection in pediatric patients from endemic areas of Mexico

In Chagas disease the clinical, acute and chronic manifestations are the result of the interaction between the parasite and the host factors. The balance between inflammatory and anti-inflammatory immune responses is essential for the increase or resolution of the manifestations in individuals infected with T. cruzi. To identify if children with chronic Chagas disease and heart injury is related with non-regulated Th1, Th2 and Th17 responses. We included 31 children with T. cruzi confirmed chronic infection from endemic areas of Mexico. Subsequently, they were separated according to their ECHO and ECG results into three groups according to the severity of cardiac involvement. Circulating Th1, Th2 and Th17 cytokine profiles were performed by Luminex assays and the results were analyzed by bivariate and multivariable analysis. Patients were classified in asymptomatic chronic (group 1, N=12); individuals with IRBBB in ECG and incipient lesions in ECHO (Group 2, N=8) and Patients with severe chronic symptomatic disease (Group 3, N=11). The analysis of immune mediators revealed that patients with severe cardiac manifestations had significant higher levels (p <0.05) of Th17 related cytokines including IL-17 and IL-6 as well as IFN-γ and IL-2. Also patients with severe cardiomyopathy exhibit increased levels of IL-13 (p <0.05) after multivariate analysis. High levels of Th17 related cytokines including IL-17, IFN-γ, IL-6 and IL-2 and pro-fibrotic factors such as IL-13 could be associated to the severity of cardiac involvement in children with chronic T. cruzi infection. These cytokines could be useful as indicators for the early identification of cardiac damage associated to the T. cruzi infection.

Performance of 5 different displays in the detection of artificial incipient and recurrent caries-like lesions

The aim of this study was to assess whether auto-calibrating medical-grade monitors perform better than off-the-shelf monitors and tablet computers in detecting artificial incipient and recurrent caries-like lesions. Sixty extracted teeth (30 premolars and 30 molars) were selected. All molars received class II amalgam and composite restorations. A 7-mm2 area on the crowns of half of the teeth was demineralized. Phantoms consisting of 4 teeth were created. Three observers using a 5-point scale evaluated digital periapical radiographs for the presence of caries on 5 displays: 2 autocalibrating medical-grade monitors, 2 tablets, and 1 off-the-shelf monitor. Sensitivity, specificity, accuracy, and receiver operating curve data were calculated and verified through analysis of variance and Tukey tests. Observer agreements were assessed using Cohen's κ test. Intraobserver agreement ranged from 0.347 to 0.612 (molars) and 0.617 to 0.811 (premolars). Interobserver agreement ranged from 0.239 to 0.559 (molars) and 0.657 to 0.858 (premolars). The performances of tablets and the off-the-shelf monitor were similar to medical monitors when the same tooth groups were compared. Medical-grade monitors presented fewer statistically significant differences when different lesions where compared within the same display and restorative material. Evaluations of similar lesions were not significantly different among the 3 types of displays. However, the autocalibrating medical-grade monitors performed better when incipient and recurrent lesions were compared.

Effectiveness of different preventive agents on initial occlusal and proximal caries lesions: A follow-up study

Background/purposeMonitoring the effects of different caries-preventive agents on initial caries lesions in orthodontic patients is important. Therefore, the purpose of this study is to investigate the efficacy of different preventive methods in preventing occlusal and proximal incipient lesions (ILs) during fixed orthodontic treatment. Materials and methodsForty-eight subjects at the beginning of fixed orthodontic treatment were included. All subjects were well educated and motivated to use the fluoride toothpaste (Colgate Total, 1450 ppm F) three times a day during the study period. Four different groups were created with a split-mouth design: placebo, fluoride gel, fluoride varnish, and chlorhexidine varnish. The occlusal surfaces of the second molar teeth were assessed with DIAGNOdent pen (DD) during the first 12 months (6th and 12th), and the proximal surfaces of each quadrant were monitored using bitewing radiographs until the 24th month (baseline and 24th month). ResultsThe mean DD values increased in each group during the first 6 months compared to the baseline, but a significant increment was only obtained in the control and fluoride gel groups (p < 0.05). Fluoride and chlorhexidine varnish had significantly more preventive effects than the control and the fluoride gel for occlusal surfaces at the 6th and 12th month and for intact proximal surfaces at the 24th month, but no significant differences were found between the two varnish groups (p > 0.05). No significant differences were found between the four methods in terms of caries progression for proximal ILs after 24 months. ConclusionEffective toothbrushing with 1450 ppm fluoridated toothpaste and topical fluoride gel application seems to be inadequate for prevention of new proximal ILs during fixed orthodontic treatment. Fluoride and chlorhexidine varnish showed more protection in relation to occlusal surfaces.

Diagnostic validity of ICDAS II, VistaProof and a combination of these two methods. An in vitro study in pre-cavitated lesions.

In view of the present fall in advanced cavitation lesion prevalence, diagnostic methods have been developed to assist in assessing and measuring pre-cavitation lesions. The purpose of this study was to assess the VistaProof fluorescence-based system in vitro and compare the results with those of visual examination using the ICDAS II criteria. 100 permanent teeth were collected and 65 were chosen at random for this study. Two separate examiners each examined them twice, 3 weeks apart, assessing them in accordance with ICDAS II. They were subsequently examined with the VistaProof system and the images were stored in the computer program. After obtaining all these data, the teeth were prepared for histological examination and the extent of the lesion was measured. The sensitivity with VistaProof was 0.705 for examiner 1 and 0.818 for examiner 2. With ICDAS II it was 0.796 and 0.864, respectively. The specificity was 0.810 and 0.619, respectively, for VistaProof and 0.810 and 0.952 for ICDAS II. The agreement with the histology results was 0.757 and 0.719, respectively, for VistaProof and 0.802 and 0.908 for ICDAS II. The intra-examiner and inter-examiner reproducibility of both methods was also assessed. For VistaProof the values were 0.76 and 0.78 intra-examiner agreement and 0.65 inter-examiner. For ICDAS II they were 0.82 and 0.91 intra-examiner and 0.76 inter-examiner. The data showed that both ICDAS II and VistaProof presented very good sensitivity but moderate specificity, as well as strong agreement (fair to good) with the histology results, and the intra-examiner and inter-examiner reproducibility was significant for both methods. ICDAS II criteria and the assistance provided by VistaProof increase the ability to diagnose incipient lesions and take early action to treat them. It is important to combine the two in order to obtain more significant results, considering non-opperative treatments for non-cavitated lesions diagnosed. Lasers Surg. Med. 50:166-173, 2018. © 2017 Wiley Periodicals, Inc.

Silver diamine fluoride remineralized artificial incipient caries in permanent teeth after bacterial pH-cycling in-vitro

ObjectivesTo investigate the remineralizing effect of 38% silver diamine fluoride (SDF) application on enamel artificial caries in adjunct to 1000ppm fluoride toothpaste compared with fluoride toothpaste alone by analyzing the mineral density, depth of remineralization, and remineralization percentage of the lesions. MethodsEighteen artificial caries slabs were created from the proximal surfaces of nine chemically demineralized premolars. The slabs were scanned by Micro-Computed Tomography (Micro-CT) to determine the baseline mineral density of the initial lesions and randomly allocated into 2 groups. The test group was applied with 38% SDF in adjunct to fluoride toothpaste and the control group was treated with fluoride toothpaste alone. The specimens underwent bacterial pH-cycling for 5 d and were re-evaluated using Micro-CT. The pre-treatment and post-treatment mineral densities were plotted and the areas under the curves were used to calculate the remineralization percentage of both groups. ResultsMineral density significantly increased in both groups after pH-cycling (p<0.05) although to different depths (control group=260μm, test group=300μm). The test group demonstrated a significantly higher mineral density to a depth of 120μm and higher remineralization percentage (p<0.05) compared with the control group. ConclusionThe adjunctive use of 38% SDF enhances the remineralization of initial carious lesions based on mineral density, depth, and remineralization percentage compared with the use of 1000ppm fluoride toothpaste alone. SDF might be used as an adjunct to fluoride toothpaste to remineralize incipient caries lesions on smooth tooth surfaces. Clinical significanceIn non-compliant patients, the application of 38% SDF might be used as an adjunct to fluoride toothpaste, to remineralize incipient caries lesions of permanent teeth where esthetics is not a concern.

Effect of CPP-ACP paste with and without CO2 laser irradiation on demineralized enamel microhardness and bracket shear bond strength.

ABSTRACTIntroduction: Many patients seeking orthodontic treatment already have incipient enamel lesions and should be placed under preventive treatments. The aim of this in vitro study was to evaluate the effect of CPP-ACP paste and CO2 laser irradiation on demineralized enamel microhardness and shear bond strength of orthodontic brackets. Methods: Eighty caries-free human premolars were subjected to a demineralization challenge using Streptococcus mutans. After demineralization, the samples were randomly divided into five equal experimental groups: Group 1 (control), the brackets were bonded without any surface treatment; Group 2, the enamel surfaces were treated with CPP-ACP paste for 4 minutes before bonding; Group 3, the teeth were irradiated with CO2 laser beams at a wavelength of 10.6 µm for 20 seconds. The samples in Groups 4 and 5 were treated with CO2 laser either before or through CPP-ACP application. SEM photomicrographs of a tooth from each group were taken to observe the enamel surface. The brackets were bonded to the buccal enamel using a conventional method. Shear bond strength of brackets and ARI scores were measured. Vickers microhardness was measured on the non-bonded enamel surface. Data were analyzed with ANOVA and Tukey test at the p< 0.05 level. Results: The mean shear bond strength and microhardness of the laser group were higher than those in the control group and this difference was statistically significant (p< 0.05). All groups showed a higher percentage of ARI score 4. Conclusion: CO2 laser at a wavelength of 10.6 µm significantly increased demineralized enamel microhardness and enhanced bonding to demineralized enamel.

Preventive and Therapeutic Proximal Sealing: A 3.5-Year Randomized Controlled Clinical Trial Follow-Up

Objective: The aim of this split-mouth, randomized controlled clinical trial was to evaluate the efficacy of proximal sealing for avoiding the development of new caries lesions or arresting incipient caries lesions on the mesial surface of first permanent molars (6m) abutting lesions on the distal surface of second primary molars (05d) in children at high caries risk. Methods: A total of 61 children 8-10 years old were selected based on the caries status of the proximal sites of 05d and 6m. Children with caries on 05d and caries-free 6m were placed in the preventive sealing group and children with caries on both 05d and 6m in the therapeutic group. The children in each group had one 6m surface pair and in each pair one 6m surface was randomly allocated to receive a preventive or therapeutic sealing. Using a split-mouth design, the other 6m surface in the pair served as control. Results: After 3.5 years, standardized follow-up radiographs were obtained for the 45 children who remained. In the preventive sealing group, 4 out of 30 (13.3%) sealed and 16 out of 30 (53.3%) unsealed sound 6m surfaces had developed new caries lesions (p = 0.004, McNemar test). In the therapeutic sealing group, the progression of the carious lesions on 6m was observed in 3 out of 15 sealed (20.0%) and 8 out of 15 (53.3%) unsealed caries control surfaces (p = 0.06). Conclusions: Preventive sealing on sound 6m surfaces abutting 05d lesions in children at high caries risk efficaciously prevents the development of caries lesions. Therapeutically sealing active non-cavitated caries lesions reduces the progression.

Dental Faculty Accuracy When Using Diagnostic Codes: A Pilot Study.

The aim of this study was to examine the accuracy of dental faculty members' utilization of diagnostic codes and resulting treatment planning based on radiographic interproximal tooth radiolucencies. In 2015, 50 full-time and part-time general dentistry faculty members at one U.S. dental school were shown a sequence of 15 bitewing radiographs; one interproximal radiolucency was highlighted on each bitewing. For each radiographic lesion, participants were asked to choose the most appropriate diagnostic code (from a concise list of five codes, corresponding to lesion progression to outer/inner halves of enamel and outer/middle/pulpal thirds of dentin), acute treatment (attempt to arrest/remineralize non-invasively, operative intervention, or no treatment), and level of confidence in choices. Diagnostic and treatment choices of participants were compared to "gold standard" correct responses, as determined by expert radiology and operative faculty members, respectively. The majority of the participants selected the correct diagnostic code for lesions in the outer one-third of dentin (p<0.0001) and the pulpal one-third of dentin (p<0.0001). For lesions in the outer and inner halves of enamel and the middle one-third of dentin, the correct rates were moderate. However, the majority of the participants chose correct treatments on all types of lesions (correct rate 63.6-100%). Faculty members' confidence in their responses was generally high for all lesions, all above 90%. Diagnostic codes were appropriately assigned by participants for the very deepest lesions, but they were not assigned accurately for more incipient lesions (limited to enamel). Paradoxically, treatment choices were generally correct, regardless of diagnostic choices. Further calibration is needed to improve faculty use and teaching of diagnostic codes.

Diagnosis of occlusal caries lesions in deciduous molars by coherent light scattering pattern speckle

BackgroundThis study presents the correlation between laser speckle images and detection of incipient caries lesions from changs in the microstructure of the surface of tooth enamel. MethodsWe used 30 healthy deciduous molar teeth collected from the Biobank Human Teeth, Faculty of Dentistry, University of São Paulo who had carious lesions induced by the pH cycling method. The samples were evaluated for the diagnosis of caries by two methods ICDAS and speckle pattern of coherent light scattering after 5, 10 and 15days and the results were statistically analyzed using α=0.05 significance level. ResultsA significant difference was observed between the image of the speckle scattering of healthy and injured areas within the 3 study groups, but not when comparing the three groups, showing us that it is an innovative technique that needs further study, but can be used as a diagnostic method for the detection of early caries lesions. ConclusionIt can be concluded that the analysis of scattering speckle pattern is a diagnostic technique that provides information on the microstructure of the surface of tooth enamel which has sensitivity for detection of incipient caries lesions.

Observations of Enamel Microstructure in Incipient Lesions Remineralized by NaF Dentifrices

Synchrotron Radiation (SR) Wide-angle X-ray Diffraction (WAXD) and Small-angle X-ray Scattering (SAXS) techniques were used to assess microstructure of bovine enamel white-spot lesions (WSL) evaluated in a 10-day pH cycling model comprising three different dentifrice groups: (A) 0.21% NaF plus TCP (Clinpro Tooth Crème), (B) 1.1% NaF plus TCP (Clinpro 5000), or (C) 0% NaF (Tom’s of Maine) dentifrice. Each day consisted of four 2-minute treatments, one 4-hour acid challenge (pH=5.0), and immersion in artificial saliva (pH=7.0) between these events. These specimens were also examined with cross-sectional microhardness, digital light microscopy and FE-SEM (field emission scanning electron microscope), and demonstrated the remineralization model effected changes in subsurface microstructure. X-ray diffraction data from WAXD and SAXS were collected on enamel slab cross-sections extending from 0 μm to 150 μm, in 6 μm microbeam increments. A primary outcome of this observational study was that simultaneous WAXD and SAXS measurements were able to resolve significant differences (ANOVA, Student’s t-test, p&lt;0.05) between the effects of the two fluoridecontaining dentifrices on subsurface lesion microstructure. In particular, enamel lesions treated with 1.1% NaF dentifrice group manifested an abundance of nanometer-sized crystallites, while treatment with the 0.21% NaF dentifrice produced larger apatite-like crystals. While the presence of fluoride in both cases promoted regularity in crystal size and orientation, this was not observed for lesions treated without fluoride. Altogether, our observations demonstrate the pathological processes for remineralization are markedly influenced by the presence and concentration of fluoride, the microstructural characteristics of which can be distinguished using the simultaneous WAXD and SAXS technique.

In-vitro quantitative evaluation of the effectiveness of different techniques on the of incipient enamel demineralization

Aim and objective: The aim of this study was to evaluate the effectiveness of three different techniques on treating induced incipient enamel demineralized lesions using digital subtraction radiography (DSR). Materials and methods: Fifteen human sound premolars were used in this study. White spot lesions (WSLs) were established on the buccal, palatal, or lingual surfaces of the samples. Samples were then randomly divided into three equal groups (n = 10). Samples in group A were treated with ACT anticavity fluoride mouthrinse, those of group B were treated with MI paste Plus cream, while those of group C were treated with ICON resin infiltrant. All groups were exposed to a pH cycling, for 30 days excluding weekends where samples were stored in distilled water, during which the treatment regimen was applied. All groups were then exposed to a secondary demineralization attack. Standardized periapical radiographs were taken at four times interval; before any treatment which is considered as the baseline, after WSL creation, after material application, and lastly, after the second demineralization attack. DSR was used for the assessment of WSLs progression. Results: Statistical analysis was conducted using one-way analysis of variance, Tukey's and paired t-tests (P Results: ACT mouthrinse, MI paste Plus, and ICON resin infiltrant are effective materials in treating the incipient lesions and in resisting caries recurrence.