Enamel Caries Research Articles

Effect of phosphate group on remineralization of early enamel caries regulated by amelogenin peptide.

To show the effect of the phosphate group on the remineralization process of early enamel caries mediated by amelogenin peptide. Freshly extracted, completed, and crack-free bovine teeth were used to create artificial early enamel caries, which were randomly divided into four groups: Group A: fluorination remineralized solution treatment group; Group B: pure remineralized solution treatment group. Group C: 100 g/ml recombinant Amelogenin peptide remineralized solution treatment group (with single phosphate group on N-terminus); Group D: 100 g/ml non-phosphorylated recombinant Amelogenin peptide remineralized solution treatment group (without single phosphate group on N-terminus). For 12 days, fresh remineralized solutions were replaced daily. Transverse microradiography (TMR) was used after remineralization to determine mineral loss and demineralization depth before and after each sample's remineralization. Each sample's depth of remineralization and mineral acquisition were then determined. The recombinant amelogenin peptide group significantly outperformed the non-phosphorylated amelogenin peptide group in terms of mineral acquisition and mineralization depth (P<0.05). The recombinant Amelogenin's solitary phosphate group at the N-terminus helps recombinant Amelogenin to encourage the remineralization process of early enamel caries.

Evaluation of incipient enamel-carious–like lesion treated with hydroxyapatite-chitosan nanocomposite hydrogel

Non-invasive restoration of tooth enamel is a topic of high relevance in dental material science. Multiple approaches have been proposed to reach optimum reconstruction results. The current study was performed to evaluate the cross-sectional microhardness besides mineral quality and content in artificially induced carious enamel after treatment with hydroxyapatite-chitosan (HAp-CS) nanocomposite gel. Artificially carious lesions were induced by immersion of teeth in acidic carboxymethyl cellulose gel (pH 4.95-5) for 24- and 72-hours periods. Two different compositions of HAp-CS nanocomposite hydrogel were prepared with two different ratios 50/50 (%) and 70/30 (%), respectively. Additionally, sodium fluoride gel (1000 ppm concentration) was prepared and used as reference. Gels were applied to carious lesions twice/day for 3 min/each. After 45 days of application, surface morphology, energy dispersive x-ray spectroscopy, micro-Raman analysis in addition to cross-sectional microhardness were evaluated. Statistical analysis was performed using two-way ANOVA and Tukey's post hoc statistical tests. Surface morphological evaluation of treated surfaces showed obliteration of surface irregularities. Groups demineralized for 24 hours and treated with 70/30 (HAp-CS) showed highest significant cross-sectional-microhardness (P ≤ 0.05). Evaluated subsurface cross-sectional microhardness showed better mineral quality for groups demineralized for 24 hours and treated with HAp-CS nanocomposite gels. Nanocomposite gel with 70/30 (HAp-CS) could efficiently improve cross-sectional microhardness and both minerals composition and quality for lesions demineralized for 24 hours. More severely induced lesions, as demineralized for 72 hours, need more powerful agent compositions and/or prolonged application protocols for improvement.

Effect of Bleaching Agents on Healthy Enamel, White Spots, and Carious Lesions: A Systematic Review and Meta-Analysis.

This systematic review examines studies focusing on tooth bleaching and its effects on healthy enamel or incipient caries and bacterial adhesion. The aim is to explore the impact of different bleaching agents on incipient caries lesions and healthy enamel. Clinical studies, in vitro studies, and observational studies that compared at least two groups were included. A search strategy was used to select studies from the MEDLINE via Pubmed and Scopus databases. Two evaluators performed data extraction, screening, and quality assessment independently. Only studies written in English were included. From 968 initial records, 28 studies were selected for a full-text evaluation. Of these, 7 studies were classified as cluster 1 (bacterial adherence on teeth), 12 studies as cluster 2 (no bacteria involved), 4 studies as cluster 3 (no teeth deployment), and 5 clinical studies were cluster 4. Of the selected studies, 6 (21.4%) supported increased bacterial attachment capacity and cariogenic dynamics, 4 (14.3%) decreased adhesion and cariogenic activity, 7 (25%) showed no difference, and 11 (39.3%) followed a different methodological approach and could not be categorized. The risk of bias appeared to be high, mainly because of the different methodologies in the studies, so we cannot reach a confident conclusion. Nevertheless, as far as carbamide peroxide bleaching is concerned, there does not seem to be a clinically significant alteration, neither in microorganism counts nor in enamel microstructure.

Progression of proximal caries in primary molars using the radiographic ICDAS: a retrospective cohort study.

To evaluate the proximal caries progression in primary molars using the radiographic International Caries Detection and Assessment System (ICDAS). A study was conducted on 196 children aged 3-9 years old who underwent the clinical examination and bitewing radiography during baseline and 6-month (and over) follow-up visits. The primary molars bitewing radiographs with initial enamel caries (RA1 and RA2) or outer dentine caries (RA3) of proximal surfaces were included. Caries advancement was scored using ICDAS criteria and statistical analyses with the chi-square test. Median survival time was evaluated using Kaplan-Meier survival curves and log-rank tests. A total of 439 surfaces of primary molars were included in this study and an averaged follow-up period of enamel and dentine caries group were 18.3 ± 9.6 months and 16.5 ± 9.5 months respectively. The progression of proximal enamel lesions significantly differed between primary maxillary and mandibular molars (p = 0.002) and among each patient's primary mandibular second molar and the others (p = 0.002). On the contrary, the outer dentine caries of each group of primary molars was not different. The median survival time of the initial enamel proximal caries (23.30 months) was non-significantly longer than that of the dentine (20.80 months). Progressions of the initial enamel proximal caries were significantly different among primary molars at the average 18.3-month follow-up. The median survival period of the enamel proximal caries was more extended than that of dentine but without statistical difference. These results provide essential information for dentists regarding an appropriate appointment for bitewing examinations.

Remineralization and Antibacterial efficacy of Ashwagandha, Maca and Ginger-based mouthwashes versus Fluoride-based mouthwash on initial enamel caries: An in-vitro study

Remineralization and Antibacterial efficacy of Ashwagandha, Maca and Ginger-based mouthwashes versus Fluoride-based mouthwash on initial enamel caries: An in-vitro study

Clinical and Radiographic Progression of Proximal Enamel Caries of Primary Molars Following the Application of Resin Infiltrant vs Tooth Mousse.

Resin infiltration is a technique in which a low-viscosity resin penetrates the proximal carious lesions and stops caries progression. This study aimed to compare the progression of proximal enamel caries of primary molars following the application of resin infiltrant clinically and radiographically vs Tooth Mousse. This case-control split-mouth study evaluated 64 proximal surfaces of primary molars in 32 patients. Each patient had one pair of noncavitated proximal caries in two primary molars from different quadrants with radiographic evidence of enamel involvement. The carious lesions in each patient were randomly treated with resin infiltrant and Tooth Mousse. Progression of carious lesions was evaluated clinically and radiographically after 12 months. The two groups were compared by Fisher's exact test. No caries progression was noted in the resin infiltrant group at 12 months, and all 32 surfaces (100%) showed cessation of caries. Four surfaces (12.5%) in the Tooth Mousse group showed caries progression. The two groups were not significantly different in this regard (p = 0.242). Resin infiltrant and Tooth Mousse were both effective in stopping the progression of proximal enamel caries of primary molars. Baniebrahim G, Seraj B, Ghonche Z, et al. Clinical and Radiographic Progression of Proximal Enamel Caries of Primary Molars Following the Application of Resin Infiltrant vs Tooth Mousse. Int J Clin Pediatr Dent 2024;17(4):385-389.

Exploration of Various Extracts of Adhatoda vasica for Use in Orthodontics

Fixed appliances used in orthodontics can alter the oral microbiota, leading to an increase in aggressive gram-positive and gram-negative bacterial species. These bacteria are strongly associated with enamel and dentin caries and periodontal disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for pain control during orthodontic treatment which can affect tooth movement and lengthen treatment time. The study evaluated the use of Adhatoda vasica in various aspects of orthodontics. The study involved the extraction of plant material, qualitative phytochemical analysis, GC-MS analysis, antibacterial activity testing, and in vitro toxicity testing on bone cell lines. The results showed that Adhatoda vasica extracts had antimicrobial activity against various pathogens and demonstrated cytocompatibility with bone cell lines. The hydroalcoholic and pet ether extracts showed the most promising results. The study highlights the impact of fixed appliances on oral microbiota, the potential role of Adhatoda vasica in orthodontics, and the need for further research in this area.

Examining the Efficacy of 38% Silver Diamine Fluoride in Halting Active Dental Caries Lesions Among Children: A Descriptive Study.

Dental caries, a prevalent issue among children, often leads to discomfort and potential complications. Utilizing caries-arresting treatments to slow down its progression offers a practical alternative. Previous research indicates that topical fluorides can deactivate and remineralize enamel caries. This study aims to evaluate the efficacy of 38% silver diamine fluoride (SDF) in halting active dental caries lesions in children. This descriptive case series was conducted at the Operative Dentistry Department of the Nishtar Institute of Dentistry in Multan, Pakistan. We enrolled 753 patients aged three to nine years, of both genders, each with at least one cavitated lesion graded 3-6 according to the International Caries Detection and Assessment System (ICDAS). SDF was directly applied to dried and isolated teeth using a micro brush and left to absorb for up to two minutes (adjusted based on the child's cooperation), and parents were instructed to ensure the child refrained from eating or drinking for an hour post-application. Baseline examinations were performed by consultant restorative dentists, and reexaminations were conducted after two to three weeks by a consultant unaware of the study. The study included children aged three to nine years, with a mean age of 6.02±1.35 years. The majority of patients (61.75%) were aged between three and six years. Among the 753 patients, 619 (82.20%) were male, and 134 (17.80%) were female, with a male-to-female ratio of 4.6:1. The efficacy of 38% SDF in arresting active dental caries lesions in children was observed in 720 (95.62%) patients. This study demonstrates that 38% SDF is highly effective in halting active dental caries lesions in children.

Effectiveness of CO2 laser conjugation with topical fluoride for caries prevention through improved enamel microhardness

Background: Dental caries is a major global health problem. According to Basic Health Research 2018, the prevalence of caries in Indonesia reached 45.3%, therefore preventions are needed to reduce the prevalence of caries. One of the preventions that can be done is the use of CO2 lasers combined with topical fluoride. Objective: To determine the effectiveness of CO2 laser conjugation with topical fluoride for caries prevention. Methods: In this article review, a method of finding theories and research articles was implemented using the keywords "CO2 laser, topical fluoride, enamel caries, microhardness, prevention" on sites Google Scholar and PubMed. Results: From the article search, 8 journals that met our requirements were found, included in them are 3 literature reviews and 5 research articles. Discussion: In several studies, it was found that a CO2 laser with a wavelength of 10.6 μm is effective to reduce the solubility of hydroxyapatite crystals on the enamel surface under acidic conditions. Meanwhile, the use of topical fluoride can also reduce demineralization and increase enamel remineralization through physical and chemical prevention. However, the effect of topical fluoride is partial and depends on its constant presence in the oral cavity. Conclusion: CO2 laser with the application of topical fluoride can work synergistically in increasing the microhardness of the enamel as an effort to prevent caries.

Combined Effect of a Bioinspired Self-Assembling Peptide and Fluoride Varnish on Remineralisation of Artificial Early Enamel Caries Lesion: An in vitro Study

Introduction: This study aimed to investigate the remineralisation effect of combined use of a bioinspired self-assembling peptide (P26) and fluoride varnish on artificial early enamel caries lesions. Methods: Bovine enamel blocks with artificial early enamel caries lesions were prepared. The blocks were randomly allocated to four experimental groups to receive the following treatments: A = P26 + fluoride varnish, B = P26, C = fluoride varnish, and D. distilled water (negative control). The treated blocks were subjected to pH cycling. Enamel blocks were collected at time points of 7 days (d7) and 21 days (d21). The mineral gain, elemental analysis and crystal characteristics of the caries lesion were assessed by micro-computed tomography, scanning electron microscopy with energy dispersive X-ray and X-ray diffraction (XRD), respectively. Results: The mean ± standard deviation of mineral gain of group A to D were 17.4 ± 4.2%, 10.7 ± 2.2%, 10.1 ± 1.2%, and 6.8 ± 0.5% at d7, respectively, and 15.2 ± 2.6%, 8.7 ± 3.1%, 9.7 ± 1.2%, and 7.8 ± 2.3% at d21, respectively. A significant higher mineral gain was observed in group A when compared to other groups at both d7 and d21 (p < 0.05). The calcium-to-phosphate ratio remained consistent across all groups, ranging between 1.2 and 1.4. XRD analysis indicated that crystal composition on the surfaces was apatite for all groups. Conclusion: In conclusion, the present study provided a first indication of better remineralisation effects of the combined use of the bioinspired self-assembling peptide P26 and fluoride varnish compared to the effects of the respective individual uses of P26 or fluoride varnish.

Occlusal Caries Detection with Intraoral Scanners in Pediatric Dentistry: A Comparative Clinical Study.

Background: The aim of this clinical study was to compare the occlusal caries detection (OCD) performance of the intraoral scanners (IOSs) Trios 4 (TIO, 3Shape) and Emerald S (EME, Planmeca) and the Diagnocam (DIA, KaVo) with the established visual (WHO) examination (VIS, reference method). Methods: Between 08/2022 and 02/2023, 60 children (mean age 9.6 ± 2.5 years) were examined as part of their regular dental checkups. OCD was performed at the tooth level, separately for primary and permanent unrestored teeth. Furthermore, two thresholds were analyzed: sound versus overall caries (pooled data of enamel and dentin caries, TH1) and pooled data of sound and enamel caries versus dentin caries (TH2). Results: The best agreement with the reference method (reliability) in both dentitions was obtained for DIA (ĸ = 0.829/ĸ = 0.846; primary/permanent teeth), followed by EME (ĸ = 0.827/ĸ = 0.837) and TIO (ĸ = 0.714/ĸ = 0.680). Similar results were shown for the diagnostic quality (sensitivity, specificity and area under the curve of the receiver operating characteristic curve), with higher values for TH1 than for TH2. Both IOSs and the DIA showed worse results than the reference method VIS. Conclusions: Currently, IOS should be used as an additional caries detection tool, especially for visualization, and cannot be recommended as a basic tool for diagnosis or invasive/noninvasive therapy decisions in OCD.

Effect of Different Tea in Remineralization of Artificially- Induced Initial Enamel Caries of Human Teeth (Study in Vitro)

One of the beneficial effects of consumption different types of tea is preventing tooth decay that attributed to their mineral contents. Purpose: to investigate the microscopical changes of different types of tea ; Camellia sinensis (black and green), Mentha spicata and Ocimum basilicum on artificially- induced initial enamel caries. Initial enamel caries-like lesions were introduced in 30 sound extracted human 1st premolar teeth using pH cycling procedure. Teeth were divided into 6 groups to test 4 types of tea ( black, green, Mentha spicata and Ocimum basilicum) and 2 control solutions (0.05%NaF and de-ionized water as positive and negative control respectively )for enamel re-mineralization, using polarized microscope. The concentration of calcium, inorganic phosphorous and fluoride ions in all tea solutions were also measured. Results revealed that green tea produced the best enamel remineralization, while black tea and Mentha spicata were coming next and result in different mode of re-mineralization. On the other hand, teeth treated Ocimum basilicum showed mild evidence of re-mineralization.The chemical analysis indicated that both Mentha spicata and Oci mum basilicum had the highest calcium and phosphorous ion s levels (higher than their fluoride concentration). Green tea had nearly equal concentration for the 3 tested ions, which were l ess than its counterpart black tea. All selected tea solutions were effective in remineralizing of initial enamel caries, in the following sequence: green tea, black / Mentha spicata , then Ocimum basilicum.

Integrated approach to the study of biodegradation of composite materials for the restoration of hard dental tissues

Objective. To study the stress-strain state of demineralized tooth enamel after its impregnation with a low-viscosity composite in a long-term period of functioning in the oral cavity in a series of equivalent cyclic tests; to study the correlation of the experimental results with clinical observations of the treatment of enamel caries using a modified infiltration technique. Materials and methods. The parameters of laser holographic interferometry and atomic force microscopy, reflecting the timing, type and severity of deformation defects in samples of demineralized tooth enamel were analyzed in a series of equivalent cyclic tests. During the experiment the samples underwent classical infiltration with composite using ICON technology (main group) and a 2-stage enamel caries treatment technique, including carrying out a time-modified conditioning of classical infiltration and the final stage (stages) of enamel coating with a bioactive hybrid glass ionomer (comparison group). Results. The first signs of the deformation defects generation in demineralized enamel filtered on the classical method (the appearance of perifocal microcracks) were recorded in 11.2 % of the tested samples after 0.9 · 106 cycles (equivalent to 9 months of functioning of a tooth with treated enamel caries in the oral cavity), during further cyclic tests the percentage of samples with local defects increased progressively. Signs of a violation of the stress-strain state in the enamel after combined treatment (samples of the comparison group) were revealed in cycles corresponding to 2–3 years of being in an artificial environment of the oral cavity. Experimental data correlated with the clinical observations both in time and frequency of complications (secondary/recurrent caries) in the long term after treatment of enamel caries by various methods. Conclusions. In the process of equivalent cyclic tests, heterogeneous elastic-plastic deformations develop in the thickness of a section of demineralized enamel impregnated with a flowing composite and along its perifocal zones, most pronounced at the interface between intact and treated enamel, which leads to the development of local defects, delaminations, cracks, and destruction of the structurally heterogeneous environment of tooth enamel. According to the results of the comparative analysis, the most favorable results in terms of the timing of development, frequency and severity of deformation defects were obtained in samples of demineralized enamel after its treatment using a modified caries infiltration technique followed by coating with a bioactive hybrid glass ionomer.

Dental student application of artificial intelligence technology in detecting proximal caries lesions.

This study aimed to investigate the caries diagnosis performances of dental students after training with an artificial intelligence (AI) application utilizing deep learning techniques, a type of artificial neural network. A total of 1200 bitewing radiographs were obtained from the institution's database and two specialist dentists labeled the caries lesions in the images. Randomly selected 1000 images were used for training purposes and the remaining 200 radiographs were used to evaluate the caries diagnostic performance of the AI. Then, a convolutional neural network, a deep learning algorithm commonly employed to analyze visual imagery problems, called "You Only Look Once," was modified and trained to detect enamel and dentin caries lesions in the radiographs. Forty dental students were selected voluntarily and randomly divided into two groups. The pre-test results of dental caries diagnosis performances of both groups were recorded. After 1 week, group 2 students were trained using an AI application. Then, the post-test results of both groups were recorded. The labeling duration of the students was also measured and analyzed. When both groups' pre-test and post-test results were evaluated, a statistically significant improvement was found for all parameters examined except precision score (p<0.05). However, the trained group's accuracy, sensitivity, specificity, and F1 scores were significantly higher than the non-trained group in terms of post-test scores (p<0.05). In group 2 (trained group), the post-test labeling time was considerably increased (p<0.05). The students trained by AI showed promising results in detecting caries lesions. The use of AI can also contribute to the clinical education of dental students.

Visualization of etching cycles efficacy at the resin infiltration into artificial enamel caries: in-vitro study on bovine teeth.

This study evaluated the effect of repeated etching cycles on resin infiltrant penetration. Enamel samples measuring 4 × 4 × 3 mm3 were obtained from the facial aspect of 50 extracted bovine teeth. Samples were immersed in a demineralization solution for 21 days to create artificial lesions and divided into five equal groups (n = 10). A 15% hydrochloric acid gel was administered to each group. The acid etching application time differed between groups: Group 1; 2 min, Group 2; 2 × 2 min, Group 3; 3 × 2 min, Group 4; 4 × 2 min, and Group 5; 5 × 2 min. Resin infiltration was visualized using a confocal laser scanning microscopy. The lesion, penetration and erosion depth (µm) were calculated, and data were statistically analyzed. The highest penetration depth (75.59 ± 9.42 µm) was seen in Group 5, followed by Groups 4, 3, 2 and 1. However, there were no statistically significant differences in the penetration depths between Groups 4 and 5 and between Groups 2, 3 and 4 (p > 0.05). In conclusion, a repeated etching cycle enhanced resin infiltrant penetration.

Potential impact of metal crowns at varying distances from a carious lesion on its detection on cone-beam computed tomography scans with several protocols.

This study evaluated the impact of artifacts generated by metal crowns on the detection of proximal caries lesions in teeth at various distances using cone-beam computed tomography (CBCT). Additionally, the diagnostic impacts of tube current and metal artifact reduction (MAR) were investigated. Thirty teeth were arranged within 10 phantoms, each containing 1 first premolar, 1 second premolar, and 1 second molar. A sound first molar (for the control group) or a tooth with a metal crown was placed. Of the 60 proximal surfaces evaluated, 15 were sound and 45 exhibited enamel caries. CBCT scans were acquired using an OP300 Maxio unit (Instrumentarium, Tuusula, Finland), while varying the tube current (4, 8, or 12.5 mA) and enabling or disabling MAR. Five observers assessed mesial and distal surfaces using a 5-point scale. Multi-way analysis of variance was employed for data comparison, with P<0.05 indicating statistical significance. The area under the curve (AUC) varied from 0.40 to 0.60 (sensitivity: 0.28-0.45, specificity: 0.44-0.80). The diagnostic accuracy was not significantly affected by the presence of a metal crown, milliamperage, or MAR (P>0.05). However, the overall AUC and specificity were significantly lower for surfaces near a crown (P<0.05). CBCT-based caries detection was not influenced by the presence of a metal crown, variations in milliamperage, or MAR activation. However, the diagnostic accuracy was low and was further diminished for surfaces near a crown. Consequently, CBCT is not recommended for the detection of incipient caries lesions.

Distinctions in molecular composition of the dental biofilm in a dependence of method of exo/endogeneous caries prevention and cariogenic condition of a patient

Comparative study of changes in the secondary structure of dental biofilm proteins in people with cariesogenic and cariesoprotective status using synchrotron IR microspectroscopy. Dental biofilm samples from 50 patients without caries (group 1) and with carious lesions of tooth enamel (group 2) were studied. The molecular composition of biofilms was studied using IR microspectroscopy. Changes in the secondary structure of dental biofilm proteins were evaluated based on deconvolution of Amide I or Amide II amide bands. using the analysis of variance. Patients of both groups took tablets containing a mineral complex with calcium glycerophosphate. Based on the deconvolution of the IR spectral profile of the Amide I and Amide II bands, the changes occurring in the secondary structure of dental biofilm proteins have been studied. Using a large set of spectra, it was shown that the prediction of the secondary structure of the biofilm protein network is influenced by both the cariesogenic situation in the oral cavity (with initial carious lesions of the enamel) and the fact that patients use a modulator - calcium glycerophosphate (a tableted mineral complex with calcium glycerophosphate). Significant intra-group and intergroup differences in the secondary structure of dental biofilm proteins were established for patients in normal and carisogenic situations in the mouth, including after the use of a tableted mineral complex with calcium glycerophosphate. This allowed us to give a mathematical assessment of shifts in the secondary structure of proteins depending on the activity of caries and external modulation. The results obtained can form the basis of a technique for spectroscopic diagnosis of changes (shifts) in the oral microbiome leading to the development of the carious process, as well as become the basis for choosing the optimal therapeutic ways to treat enamel caries, including through preventive measures aimed at restoring the microflora of the patient's oral cavity.

Dynamics of indices in the treatment of enamel caries in the stage of white (chalky) spots using microabrasion and infiltration methods

Dynamics of indices in the treatment of enamel caries in the stage of white (chalky) spots using microabrasion and infiltration methods

Encapsulation of a novel peptide derived from histatin-1 in liposomes against initial enamel caries in vitro and in vivo.

Biomimetic mineralization mediated by proteins and peptides is a promising strategy for enamel repair, and its specific application model needs more research. In this work, we exploited a liposomal delivery system for a novel peptide (DK5) derived from histatin-1 (DK5-Lips) as a new biomimetic mineralization strategy against initial enamel caries. The DK5-Lips was prepared using calcium acetate gradient method and then the in vitro release, salivary stability, and cytotoxicity were studied. Initial enamel caries was created in bovine enamel blocks and subjected to pH-cycling model treated with DK5-Lips. Surface microhardness testing, polarized light microscopy (PLM), and transverse microradiography (TMR) were analyzed. Then the biocompatibility of DK5-Lips was evaluated in the caries model of Sprague-Dawley rats, and the anti-caries effect was assessed using Micro-CT analysis, Keyes scores, and PLM in vivo. DK5-Lips provided a mean particle size of (97.63 ± 4.94)nm and encapsulation efficiency of (61.46 ± 1.44)%, exhibiting a sustained release profile, excellent stability in saliva, and no significant toxicity on human gingival fibroblasts (HGFs). The DK5-Lips group had higher surface microhardness recovery, shallower caries depth, and less mineral loss in bovine enamel. Animal experiments showed higher volume and density values of residual molar enamel, lower Keyes score, and shallower lesion depth of the DK5-Lips group with good biocompatibility. As a safe and effective application model, DK5-Lips could significantly promote the remineralization of initial enamel caries both in vitro and in vivo. The potential of liposome utilization as vehicle for oral delivery of functional peptides may provide a new way for enamel restoration.

SITUATION OF DENTAL CARIES AND GINGIVITIS AMONG ETHNIC MINORITY STUDENTS AT BOARDING SECONDARY SCHOOLS IN TUYEN QUANG PROVINCE IN 2017

Objectives: To describe the current status of dental caries and gingivitis among ethnic minority students at boarding secondary schools in Tuyen Quang province in 2017. Methods: A cross-sectional descriptive study on 1,665 ethnic minority students at 6 boarding secondary schools in Tuyen Quang Province. The characteristics of the incidence of dental caries and gingivitis were evaluated according to gender; the rates of caries of primary and permanent teeth were evaluated according to school; the rates of caries and the index of lost fillings of primary and permanent teeth, dental caries, the prevalence of tartar, and bleeding gums were evaluated according to school. Results: The rate of dental caries accounted for 59.3%, of which the rate of permanent tooth decay accounted for 52.3%; the rate of baby tooth decay was 44.6%. Among students with tooth decay, 44.4% had enamel caries; dentin caries rate accounted for 34.2%, and 21.5% had complicated caries. The index of decayed, missing, filled, teeth (DMFT) was 1.93, of which permanent teeth were 1.61, lost teeth were 0.20, and filling teeth were 0.11. The index of DMFT of milk teeth was 1.48, the index of decayed teeth was 1.21, the missing teeth were 0.15, and the filling teeth were 0.13. Gum disease accounted for 46.3% of the students studied. The rate of students with tartar was 34.1%. The average rate of students with bleeding gums was 12.3%. Conclusion: Dental caries, gingivitis, and tartar accounted for a relatively high rate among ethnic minority students at boarding secondary schools in Tuyen Quang Province.