Dentinal Lesions Research Articles

Mineral density changes in bovine carious dentin after treatment with bioactive dental cements: a comparative micro-CT study.

To evaluate the potential of conventional glass ionomer cement (GIC), Biodentine™, MTA, and Portland cement to induce mineral density changes in carious dentin compared to zinc oxide eugenol control cement (ZOE). Fifty blocks of bovine root dentin were prepared and a biofilm model using ATCC strains of S.mutans, S.sobrinus, and L.casei was used to promote artificial dentin lesions. After demineralization, the blocks were randomly divided into the five cement groups. Half of the surface of each specimen received the tested material and the other half was covered with wax (control). Samples were stored in phosphate buffered saline solution for 30days and after that were scanned in a micro-CT with standardized parameters. Dentin mineral density changes were calculated using differences in plot profiles of the exposed and control carious dentin. Friedman's test, followed by Wilcoxon signed-rank test was used with 5% significance. Mean ΔZ values for the cements were 48.63 ± 19.09 for the control (ZOE), 63.31 ± 32.59 for Biodentine™, 114.63 ± 72.92 for GIC, 109.56 ± 66.28 for MTA, and 106.88 ± 66.02 for Portland cement. All cements showed a statistically significant increase in ΔZ values compared to the control, but Biodentine™ values were statistically significantly lower compared to GIC and the other calcium silicate cements. Tested materials present potential to induce mineral density changes in carious bovine dentin. MTA, Portland, and GIC showed higher bioactivity potential than Biodentine™. Based on minimally invasive concept, materials with remineralization potential can be used to preserve diseased but still repairable dental tissue.

Analysis of glucosyltransferase gene expression of clinical isolates of Streptococcus mutans obtained from dental plaques in response to sub-lethal doses of photoactivated disinfection.

Dental caries is a disease caused by a group of oral streptococcal microorganisms, primarily Strptococcus mutans. Photoactivated disinfection (PAD) has been proposed as a conservative method for treatment of carious lesions. Therefore, the aim of this study was to assess the effectiveness of indocyanine green (ICG)- and toluidine blue O (TBO)-PAD as supplementary tools in reducing the bacterial load and expression profiling of the gene associated with the biofilm formation in S. mutans. S. mutans strains were isolated from dental plaque samples collected from 212 patients through conventional biochemical tests and molecular methods. After identification, S. mutans strains were photosensitized in vitro with TBO and ICG, which were excited at a specific light wavelength based on the photosensitizer. After evaluating doses of TBO- and ICG-PAD contributing to sub-significant reduction of CFU/mL, ROS levels were measured with DCFH-DA fluorescent probe. Eventually, TBO- and ICG-PAD effects on the gtfB gene expression were assessed using real-time quantitative reverse transcription polymerase chain reaction. S. mutans strains were isolated from 50 (23.5%) patients. In this study, maximum doses of TBO- and ICG-PAD contributing to sub-significant reduction of CFU/mL against S. mutans strains were 23.12 μM/mL TBO at fluence of 68.75 J/cm2 and 20.15 μM/mL ICG at fluence of 31.2 J/cm2. According to the results, 3.8- and 6.1-fold increases in the fluorescence were observed in ICG and TBO treated cells compared to the control, respectively. The expression of gtfB was down regulated to approximately 3.9- and 8.25-fold following treatment with TBO- and ICG-PAD, respectively. The gtfB gene expression profiling decreased in the bacterial cells, with ICG-PAD causing a greater reduction. PAD may be a promising therapy for dentinal carious lesions.

Comparison of International Caries Detection and Assessment System and digital radiographs for detecting occlusal dental caries: An In vivo Study

Abstract Aim: The aim of the present study was to evaluate the accuracy in the diagnosis of occlusal caries lesion using International Caries Detection and Assessment System II (ICDAS II) and digital radiographs in the primary molars. Materials and Methods: A total of 35 children was selected randomly and recruited for visual ICDAS II and digital bitewing radiographic examination by two independent trained examiners. A total of 249 teeth were examined at D1 (enamel caries lesions) and D3 (dentine caries lesions) thresholds. Results: Sensitivity at D1 for ICDAS II were 95%, and 22.97% for digital radiographs While specificity was 1005 for the both tools. At D3, threshold sensitivity of ICDAS II was 94.%, whereas it was 69% for digital radiographs, while specificity was almost the same for both methods and both D1 and D3 thresholds. Excellent inter- and intra-examiner reliabilities were evident. Conclusions: ICDAS II is better than digital radiographs in detecting carious lesions confined to enamel, and both are equally effective in the detection of dentinal carious lesions.

Treatment of various degrees of white spot lesions using resin infiltration\u2014in vitro study

BackgroundThis study was conducted to evaluate the efficiency of resin infiltration to improve the color of white spot lesions (WSLs) and to estimate the effect of different numbers of etching and resin infiltrant applications on the color change of WSLs with various depths. Ninety-six sound extracted premolars were subjected to acid attack inducing different depths of WSLs. Using a DIAGNOdent, teeth were divided into four main groups according to the depth of the WSLs: shallow enamel, deep enamel, shallow dentine, and deep dentine without cavitation. Then each of the main groups was subdivided into four groups: six teeth each with different protocols of resin infiltration as follows: 1 etching + 1 infiltrant application (EA), 1 etching + 2 infiltrant applications (EAA), 2 etchings + 1 infiltrant application (EEA), 2 etchings + 2 infiltrant applications (EEAA). Spectrophotometric analysis was measured at baseline (T0), after inducing the WSLs (T1), and following resin infiltration application (T2) for each group.ResultsIn shallow enamel, EA produced the least mean color difference (1.62 ± 0.85), with high significant difference (P < 0.001), when compared with the clinically detectable threshold (ΔE = 3.7). While in deep enamel, EAA showed the least mean color change (1.95 ± 0.4), with P < 0.001 when compared with the critical value. Also, in shallow dentine, the least mean change was noticed with EAA (3.0 ± 0.45), with P < 0.001 when compared with the clinical color detection threshold. Furthermore, in deep dentine, EAA had the least mean difference (3.76 ± 0.6) but with no significant difference, when compared with the clinically detectable threshold.ConclusionsAs the WSL got deeper, the color of the lesion became more clinically visible. In shallow enamel, the best treatment option was one etching with one resin infiltrant application. For deep enamel and shallow dentine, one etching with two applications of infiltrant gave the best lesion masking. In deep dentine, it is advisable to perform one etching with two infiltration steps, taking in consideration that all deep dentine lesions without cavitation were partially masked, remained clinically detectable, and might require more invasive restorative procedures.

Dental acid etchant as a sensitizing agent in photodynamic therapy to reduce S. mutans in dentinal carious lesions.

The study aims to assess the utility of dental acid etchant containing 37% phosphoric acid and methylene blue dye (DAE) as a sensitizing agent for photodynamic therapy (PDT) to reduce Streptococci mutans in dentinal caries. Forty-five permanent third molars were sectioned and the coronal dentin exposed. A cariogenic challenge was performed using brain-heart infusion (BHI) supplemented with 0.5% yeast extract, 1% glucose, 1% sucrose, and S. mutans ATCC 25175 standardized to 0.5 McFarland turbidity. Specimens were incubated in anaerobic jars at 37°C for 15days. During this period, BHI broth was renewed every 24h. After 15days, specimens were randomly divided into three groups (n = 15): DAE, application of dental acid etchant containing 37% phosphoric acid and methylene blue dye for 15s; LLL, application of low-level laser (wavelength 660nm, energy 4J/cm2, power 5W) for 15s; and PDT, application of DAE for 15s followed by LLL irradiation (660nm, 4J/cm2, 5W). Carious tissue from each specimen was collected before and after the applications. Five decimal dilutions were performed and the resulting solution was seeded in mitis-salivarius-bacitracin agar. Plates were incubated in anaerobic jars at 37°C for 48h. Analysis of variance (ANOVA) with post hoc Tukey's test was used to compare total S. mutans counts. Significant reductions in S. mutans were observed after DAE application (40.70%, p < 0.0001), LLL (12.35%, p = 0.0036), and PDT (55.22%, p < 0.0001). Dental acid etchant containing 37% phosphoric acid and methylene blue dye can be used as a photosensitizing agent for PDT to reduce S. mutans burden in dentinal caries.

Influence of fluoride on the mineralization of collagen via the polymer-induced liquid-precursor (PILP) process

ObjectiveThe polymer-induced liquid-precursor (PILP) mineralization process has been shown to remineralize artificial dentin lesions to levels consistent with those of native dentin. However, nanoindentation revealed that the moduli of those remineralized lesions were only ∼50% that of native dentin. We hypothesize that this may be due to the PILP process having been previously optimized to obtain high amounts (∼70wt%) of intrafibrillar crystals, but without sufficient interfibrillar mineral, another significant component of dentin. MethodsFluoride was added to the PILP-mineralization of collagen from rat tail tendon at varying concentrations to determine if a better balance of intra- versus inter-fibrillar mineralization could be obtained, as determined by electron microscopy. Nanoindentation was used to determine if fluoridated apatite could improve the mechanical properties of the composites. ResultsFluoride was successfully incorporated into the PILP-mineralization of rat tail tendon and resulted in collagen-mineral composite systems with the mineral phase of hydroxyapatite containing various levels of fluoridation. As the fluoride concentration increased, the crystals became larger and more rod-like, with an increasing tendency to form on the fibril surfaces rather than the interior. Nanomechanical testing of the mineralized tendons revealed that fluoride addition did not increase modulus over PILP mineralization alone. This likely resulted from the separated nature of collagen fibrils that comprise tendon, which does not provide lateral reinforcement and therefore may not be suited for the compressive loads of nanoindentation. SignificanceThis work contributes to the development of minimally invasive approaches to caries treatment by determining if collagen can be functionally mineralized.

Microleakage analysis of dental caries lesions sealed with flow resin and compared to microhybrid resin restorations in dentin

ABSTRACT Objective: To evaluate the sealing of cavities of dentinal occlusal caries lesions, reproduced in vitro, with flow resin compared to cavity restorations presenting healthy dentin using microhybrid composite resin. Methods: The sample consisted of 27 healthy deciduous molars where cavities of approximately 2 mm in the fossa region were performed and occlusal cleft of each tooth were sealed, impermeabilization was performed and the sample was randomly divided into 2 groups: group I underwent cariogenic challenge and occlusal sealing with resin flow. The teeth of group II were restored with microhybrid composite resin. The teeth were immersed in 5% methylene blue for 8 hours at 37° C and washed until all the dye was removed from the surface. The teeth were sectioned in the mesio-distal direction. The penetration of the dye was evaluated: 0- no penetration; 1- dye penetration up to 1/3 of the restoration; 2- dye penetration up to 2/3 of the restoration depth; 3 - penetration of dye into the pulp wall. The results were analyzed by the Biostat 4.0 program. Descriptive analysis and the mode among the examiners submitted to the Mann-Whitney test. Results: There was no significant difference in microleakage between restoration performed in healthy dentin with microhybrid composite resin or maintenance of infected dentin in primary teeth sealed with resin flow (p = 0.6035). Conclusion: It was concluded that the marginal infiltration of primary molars sealed with microhybrid composite resin and resin flow was not influenced by the removal -or not -of the carious tissue or the material used.

Effect of selective carious tissue removal on biomechanical behavior of class II bulk-fill dental composite restorations

ObjectivesThis study aimed to develop a method to induce carious lesions in the pulpal floor dentin of a class II cavity preparation, and to determine the effects of this carious lesion on the biomechanical behavior of the dental composite restoration. MethodsThe pulpal floor dentin of class I cavities in sound third molars were demineralised with acetic acid for 35days followed by a 7-day exposure to pooled human saliva biofilm and demineralization was verified by micro-CT. Subsequently, the proximal walls were removed forming a class II cavity and the caries lesion was left intact or was completely removed prior to restoration with a bulk-fill dental composite (n=10). Cuspal deflection was assessed by strain-gauge and micro-CT imaging. The presence of enamel cracks was assessed by transillumination before and after restoration, and again after 1,200,000 cycles of mechanical fatigue in a chewing simulator. Finally, resistance to fracture by axial compressive loading and failure mode was determined. Data were analyzed by 2-way repeated measures ANOVA, Fisher’s exact test, and t-test (α=0.05). ResultsThe presence of carious lesions had no significant effect upon cuspal deflection, formation of enamel cracks, and fracture strength of the dental composite restorations. The restorative procedure increased the number of enamel cracks, which was not affected by mechanical cycling. SignificanceMaintaining carious lesions does not affect the biomechanical behavior of class II restorations performed with bulk-fill dental composite.

Glass hybrid restorations as an alternative for restoring hypomineralized molars in the ART model

BackgroundThis study aimed to evaluate the survival rate of glass hybrid restorations placed under the atraumatic restorative treatment (ART) technique in first permanent molars affected by molar incisor hypomineralization (MIH).MethodsSixty teeth with severe MIH associated to carious dentin lesions without pulp involvement were included. Treatments were performed by one trained dentist using the ART approach and restored with a glass hybrid restorative system (Equia Forte, GC®) on school premises. Treatments were evaluated after 6 and 12 months by an independent examiner using the modified ART criterion. Data analysis involved descriptive statistics and actuarial success analysis.ResultsThe sample comprised 24 (54.54%) girls and 20 (45.45%) boys with a mean age of 10.55 (±1.25) years. In regard to the number of surfaces involved in the restorations, 29 (48.3%) comprised one surface and 31 (51.7%) two or more surfaces. Considering cavity extent, 25 (41%) presented dentin cavitation without cusp weakness, 23 (37.7%) with large dentin cavitation with cusp weakness and 13 (21.3%) with large dentin cavitation with the breakdown of one or more cusps. Only 4 teeth required local anesthesia. A success rate of 98.3% after 6 and 12 months was observed, as only one restoration failed. The only failure occurred in a restoration involving three or more sur-faces presenting the breakdown of all cusps.ConclusionRestorations using a glass hybrid restorative system and performed in the field with the ART technique proved, after 12 months of evaluation, to be an effective approach to preserving first permanent molars affected by MIH.Trial registrationREBEC-RBR-8drccq (17/06/15).

Caries assessment spectrum treatment: the severity score

To appraise the feasibility of the caries assessment spectrum and treatment (CAST) severity score according to the formula (F) recommended in the CAST manual. Data from an epidemiological survey of 680 schoolchildren (mean age ± standard deviation: 7.45± 0.91 years), living in a low-income area in Brasília, were used. The CAST instrument was used for assessing enamel carious lesions (CAST code=3), dentine carious lesions (CAST codes=4-7) and tooth loss from caries (CAST code=8). The prevalence of carious lesions including enamel and dentine in both deciduous and permanent dentitions was 49.41% and 69.12%, respectively. Calculating the CAST severity score per child using F was unsatisfactory because of the undiscriminating weight given for each CAST code. Modification of weights according to the accepted levels of disease severity for individual CAST codes resulted in a new formula (F1), in which the weight given to cavitated dentine lesions was quadrupled in relation to that given to enamel carious lesions; this was different from F, in which the weight given to such lesions was twofold. F1 was able to categorise satisfactorily the study children into one of three levels of dental caries severity: mild (34.1%); moderate (29.5%); or severe (36.4%). According to the outcomes of the present appraisal, it was concluded that the numerical score provided by the CAST severity scores allows an overview of the severity of caries disease and the classification of individuals into mild, moderate or severe levels of dental caries when the new formula (F1) is used.

Retention rates and caries-preventive effects of two different sealant materials: a randomised clinical trial.

The aim of this study was to compare the caries-preventive effect and the retention rates of sealants prepared with a new modified and a high-viscosity glass-ionomer cement (GIC) in recently erupted first permanent molars. MATERIALS AND METHODS: Fifty-six children (224 teeth) were included in a split-mouth randomised clinical trial. All children had their four first permanent molars sealed with either Clinpro XT Varnish (CXT) or Fuji IX GP FAST (FJ). FJ sealants were placed according to the ART protocol. Retention rates and caries-preventive effect of both materials were assessed clinically after 24months, and survival curves were created according to the Kaplan-Meier method. For sealant retention rates, analyses were performed according to both the traditional method and modified sealant retention categorisation. FJ sealants were retained longer in comparison to CXT sealants (p < 0.05), regardless of the categorisation used. In relation to the caries-preventive effect, no statistically significant differences were observed between materials (p = 0.99). Sealants prepared with the high-viscosity GIC according to the ART protocol survived longer than those prepared with the modified GIC, but both materials were equally effective in preventing cavitated dentine lesions over 24months. We concluded that GIC-based sealants are effective in preventing dentine caries lesions.

Transillumination and HDR Imaging for Proximal Caries Detection

The purpose of this study was to develop an in vitro model for the validation of near-infrared transillumination (NIRT) for proximal caries detection, to enhance NIRT with high-dynamic-range imaging (HDRI), and to compare both methods, using micro-computed tomography (µCT) as a reference standard. Both proximal surfaces of 53 healthy or decayed permanent human teeth were examined using the Diagnocam (DC) (KaVo) and NIRT with HDRI (NIRT-HDRI). NIRT was combined with HDRI to improve the diagnostic performance by reducing under- and overexposed image areas. For NIRT-HDRI, an exposure series was captured and merged into a single HDR image. A classification was applied according to lesion depth. All surfaces were assessed twice by 2 trained examiners, and additionally with µCT for validation. The Kappa statistic was used to calculate inter-rater reliability and agreement between DC and NIRT-HDRI. Inter-rater reliability (weighted Kappa, wκ) showed very good agreement for the DC (0.90) and NIRT-HDRI (0.96). The overall agreement (wκ) was almost perfect (0.85). In the individual categories (0 to 4), the agreement (simple Kappa) ranged from almost perfect (category 4) to moderate (1 and 2) to substantial (categories 0 and 3). Sensitivity and specificity of sound surfaces, enamel, and dentin caries ranged from 0.57 to 0.99 and were similar for both methods in the different categories. NIRT-HDRI had a higher sensitivity for sound surfaces and enamel caries, as well as a higher specificity for dentin caries. Regarding the obtained images, HDRI allowed for the detection of caries within a greater range of luminance levels, resulting in a more detailed visualization of structures without under- or overexposure. However, HDRI this did not improve the diagnostics significantly. Distinguishing between a processed demineralized enamel and dentin lesions appears to be a problem specific to NIRT and cannot be balanced using HDRI.

Methodological issues in assessing the association between periodontitis and caries among adolescents

We aimed to investigate the association between dental caries and periodontitis among adolescents participating in a case-control study of periodontitis. In addition, we compared 2 analytical approaches to estimate the association: conventional regression and structural equation modelling (SEM). Along with periodontal recordings, data were obtained on caries, just as subgingival plaque samples were collected. Sociodemographic information was collected with a questionnaire. We used factor analyses to express the many correlated clinical periodontal dimensions in a smaller number of factors. The association between caries (counts of enamel and dentin lesions, or dentin lesions only) and periodontitis was tested using negative binomial regression with robust variance (conventional regression) and weighted least squares (SEM) estimation. Factor analysis revealed 2 different latent periodontal variables: "extent" and "severity" of periodontitis. Using conventional regression, the "extent" of periodontitis was positively associated with higher counts of dentin caries lesions, even after adjustments for maternal education and subgingival microbial composition (rate ratio 1.34; 95% CI 1.07-1.68). The "severity" of periodontitis was associated with lower counts of enamel and dentin caries lesions (rate ratio 0.85 95% CI 0.77-0.92). The SEM revealed a positive association between periodontitis "extent" and number of dentin caries lesions (coefficient 0.29; P < .0001). The "severity" of periodontitis was negatively associated with enamel and dentin caries (coefficient -0.44; P < .0001). We found an association between caries and periodontitis among adolescents. The "severity" of periodontitis was negatively associated with enamel/dentin caries, whereas the "extent" of periodontitis was positively associated with dentin caries irrespective of the analytical approach employed.

Multispectral near-infrared reflectance and transillumination imaging of occlusal carious lesions: Variation in lesion contrast with lesion depth.

In vivo and in vitro studies have demonstrated that near-infrared (NIR) light at λ=1300-1700-nm can be used to acquire high contrast images of enamel demineralization without interference of stains. The objective of this study was to determine if a relationship exists between the NIR image contrast of occlusal lesions and the depth of the lesion. Extracted teeth with varying amounts of natural occlusal decay were measured using a multispectral-multimodal NIR imaging system which captures λ=1300-nm occlusal transillumination, and λ=1500-1700-nm cross-polarized reflectance images. Image analysis software was used to calculate the lesion contrast detected in both images from matched positions of each imaging modality. Samples were serially sectioned across the lesion with a precision saw, and polarized light microscopy was used to measure the respective lesion depth relative to the dentinoenamel junction. Lesion contrast measured from NIR cross-polarized reflectance images positively correlated (p<0.05) with increasing lesion depth and a statistically significant difference between inner enamel and dentin lesions was observed. The lateral width of pit and fissures lesions measured in both NIR cross-polarized reflectance and NIR transillumination positively correlated with lesion depth.

Lesion Dehydration Rate Changes with the Surface Layer Thickness during Enamel Remineralization.

A transparent highly mineralized outer surface zone is formed on caries lesions during remineralization that reduces the permeability to water and plaque generated acids. However, it has not been established how thick the surface zone should be to inhibit the penetration of these fluids. Near-IR (NIR) reflectance coupled with dehydration can be used to measure changes in the fluid permeability of lesions in enamel and dentin. Based on our previous studies, we postulate that there is a strong correlation between the surface layer thickness and the rate of dehydration. In this study, the rates of dehydration for simulated lesions in enamel with varying remineralization durations were measured. Reflectance imaging at NIR wavelengths from 1400-2300 nm, which coincides with higher water absorption and manifests the greatest sensitivity to contrast changes during dehydration measurements, was used to image simulated enamel lesions. The results suggest that the relationship between surface zone thickness and lesion permeability is highly non-linear, and that a small increase in the surface layer thickness may lead to a significant decrease in permeability.

Approximal sealings on lesions in neighbouring teeth requiring operative treatment: an in vitro study

Objectives: With this in vitro study we aimed to assess the possibility of precise application of sealant on accessible artificial white spot lesions (WSL) on approximal surfaces next to a tooth surface under operative treatment. A secondary aim was to evaluate whether the use of magnifying glasses improved the application precision.Material and methods: Fifty-six extracted premolars were selected, approximal WSL lesions were created with 15% HCl gel and standardized photographs were taken. The premolars were mounted in plaster-models in contact with a neighbouring molar with Class II/I–II restoration (Sample 1) or approximal, cavitated dentin lesion (Sample 2). The restorations or the lesion were removed, and Clinpro Sealant was placed over the WSL. Magnifying glasses were used when sealing half the study material. The sealed premolar was removed from the plaster-model and photographed. Adobe Photoshop was used to measure the size of WSL and sealed area. The degree of match between the areas was determined in Photoshop.Results: Interclass agreement for WSL, sealed, and matched areas were found as excellent (κ = 0.98–0.99). The sealant covered 48–100% of the WSL-area (median = 93%) in Sample 1 and 68–100% of the WSL-area (median = 95%) in Sample 2. No statistical differences were observed concerning uncovered proportions of the WSL-area between groups with and without using magnifying glasses (p values ≥ .19). However, overextended sealed areas were more pronounced when magnification was used (p = .01). The precision did not differ between the samples (p = .31).Conclusions: It was possible to seal accessible approximal lesions with high precision. Use of magnifying glasses did not improve the precision.

Sodium Trimetaphosphate as a Novel Strategy for Matrix Metalloproteinase Inhibition and Dentin Remineralization

The effect of sodium trimetaphosphate (STMP) as an antiproteolytic and remineralizing agent on demineralized dentin was evaluated in vitro. The inhibitory potential of STMP at 0.5, 1.5, 3.5, and 5% against recombinant matrix metalloproteinases (MMPs) MMPs-2 and -9 was assessed by zymography. To investigate its remineralization potential, 40 bovine root specimens were obtained and subjected to a demineralization protocol to produce caries-like dentin lesions. After that, dentin surfaces were divided into 3 areas: (1) mineralized (no treatment); (2) demineralized; and (3) demineralized/treated with STMP and submitted to a pH-cycling associated or not with STMP (1.5, 3.5, or 5% STMP, 10 min of treatment). After that, superficial hardness (SH) and cross-sectional hardness (CSH) were determined. Polarized light microscopy (PLM) was used to qualitatively evaluate mineralization within the caries-like lesions. The zymographic analysis showed that STMP solution is a potent inhibitor of the gelatinolytic activity of MMPs-2 and -9 depending on the dose, since the lowest concentration (0.5%) partially inhibited the enzyme activity, while the higher concentrations completely inhibited enzyme activity. Regarding remineralization effect, only 1.5% STMP solution enhanced both the SH and CSH. PLM showed that the area treated with 1.5% STMP presented similar birefringence as mineralized sound dentin. In conclusion, 1.5% STMP solution is effective as an antiproteolytic agent against MMPs and promotes dentin remineralization.

Remineralization of Natural Human Carious Dentin Lesions with an Experimental Whisker-Reinforced Atraumatic Restorative Treatment Composite.

To evaluate the remineralization of natural human dentin caries with an experimental whisker-reinforced Atraumatic Restorative Treatment (ART) composite. Teeth with moderate active dentin caries were prepared with caries-disclosing dye and hand instruments, restored with ART or resin-modified glass ionomer cement (RM-GIC), and then wet sliced into 120-µm sections with 15 sections in each group. After taking transverse microradiographs and implementing digital image analysis to determine the "mineral-loss-before," each section was incubated in artificial saliva solution (pH = 7.0) for 4 weeks and 8 weeks with 1 hour each workday in demineralization solution (pH = 4.3). Transverse microradiographs of each section were retaken, and the "mineral-loss-after" was determined. The remineralization was calculated from [1-("mineral-loss-after"/"mineral-loss-before")] × 100%. Results were statistically analyzed with a repeated-measures ANOVA with one within-subject factor (time: 4 and 8 weeks) and one between-subject factor (material: ART and RM-GIC) (α = 0.05). The statistical analysis indicated that ART composite resulted in significantly higher remineralization than the RM-GIC (p ≤ 0.05). For the remineralization of each material, there was a statistical difference between 4 weeks and 8 weeks (p ≤ 0.05). This experimental ART composite remineralized natural human dentin caries better than the RM-GIC.

THE EFFECTIVENESS OF PROPOLIS FLUORIDE APPLICATION IN INHIBITING DENTAL CARIES ACTIVITY IN SCHOOL CHILDREN AGE 6-9 YEARS OLD

Objective: To obtain the effectiveness of propolis fluoride application in inhibiting dental caries activity. Methods: The study was included 170 children aged 6–9 years old with active dentinal carries surface was 532 tooth surfaces, all of 532 tooth surface will applicate use propolis fluoride in school children at primary school SD Kukusan. Evaluation of the amount of dentinal caries lesion that has been arrested was conducted after 1 month, 2 months, and 4 months after topical application. Results: After propolis fluoride applicated shows, that the activated process caries of dentinal caries lesion after 1 month was found in 104 tooth surfaces, 2 months were 115 tooth surfaces, and after 4 months evaluated were found significant increase to be 226 tooth surfaces on dentinal caries activated from 2nd to 4th month after application propolis fluoride (p&lt;0.01). The percentages of arrested caries in, respectively, for 1st month after the application is 99.80%, 2nd month application is 78.32%, and in the 4th month is 57.52% while the score plaque of school children was decline significantly until 36.5% (p&lt;0.05) after 4 months intervention by tooth brushing every week at school. Conclusion: The application of propolis fluoride is effective in inhibiting dentinal caries lesion activity, has the advantage of making no black discoloration to the teeth.

Structure of the Bacterial Community in Different Stages of Early Childhood Caries.

To characterise in vivo the structure of bacterial communities in decayed and sound primary teeth. Samples of biofilms were collected from three groups of patients with complete and exclusively primary dentition (n = 45): G1: sound teeth (n = 15); G2: enamel lesion (n = 15); G3: dentin lesion (n = 15). DNA was extracted (CTAB 2%) from the biofilm, the partial 16S rRNA gene was amplified with Bacteria Universal Primers (BA338fGC - UN518r) and subjected to DGGE (denaturing gradient gel electrophoresis). Multidimensional scaling and ANOSIM (analysis of similarity) were employed to determine the structure of the bacterial communities. The amplicon richness was determined by averaging amplicons, with the differences between treatments determined with ANOVA, while means were compared using Tukey's test (p < 0.05). Compared to sound teeth, a greater variety of bacterial communities was found in decayed teeth. Despite the differences between the bacterial communities of sound teeth and decayed teeth, the Venn diagram showed that the samples had 38 amplicons in common. Greater amplicon richness was observed in samples of decayed teeth (enamel: 20.5 ± 2.7; dentin: 20.1 ± 2.8) compared with the sound samples (12.0 ± 4.3) (p <0.05), indicating enhanced growth for specific groups of bacteria on decayed teeth. Although there is less bacterial diversity on sound than ECC-decayed teeth, the bacterial communities are very similar.