High-Resolution Characterization of Enamel Remineralization Using Time-of-Flight Secondary Ion Mass Spectrometry and Electron Microscopy.

INTRODUCTION: The aim of this in vitro study was to assess the suitability of high-resolution time-of-flight secondary ion mass spectrometry (ToF-SIMS) for visualizing cross-sectional changes in human enamel microstructure and chemical composition during treatment and remineralization cycling of artificially generated caries lesions underneath an artificial plaque. METHODS: Treatments consisted of exposure to twice daily toothpaste/water slurries prepared from 0, 1,100, and 5,000 µg/g fluoride (F) NaF/silica toothpastes. In addition, treatments with slurries prepared from 1,100 µg/g F SnF2/silica toothpastes were done using 44Ca in the remineralization solution to allow for differentiation of newly formed mineral and exploration of incorporated metal dopants using ToF-SIMS. Complementary microhardness, scanning electron microscopy, and high-resolution transmission electron microscopy (HR-TEM) investigations were performed on enamel cross sections. RESULTS: HR-TEM was used for the first time to determine the change in crystallinity during remineralization revealing distinct microstructural zones within one lesion. Chemical mapping using ToF-SIMS demonstrated that the distribution of F, while observed primarily in the new mineral phase, was widespread throughout the lesion with 44Ca substantially limited to the remineralizing mineral. Both penetrated the inter-rod spaces of the sound enamel illustrating how acid damage propagates into the native mineral as the caries lesion deepens. HR-TEM examination revealed different regions within the lesion characterized by distinct micro- and ultrastructures. Importantly, HR-TEM revealed a return of crystallinity following remineralization. F dose-response observations verified the ability of these high-resolution techniques to differentiate remineralization efficacy. CONCLUSION: The collective results provided new insights such as the visualization of F or calcium penetration pathways, as well as new tools to study the caries process.

Casein phosphopeptide amorphous calcium phosphate and universal adhesive resin as a complementary approach for management of white spot lesions: an in-vitro study.

BACKGROUND: White spot lesion (WSL) is the most common consequence during and after orthodontic treatment. This study was conducted to investigate the ability of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) coupled with universal adhesive resin to treat white spot lesions. MATERIAL AND METHODS: Forty-five extracted premolars were sectioned to create 90 specimens. Seventy-five specimens were demineralized to generate artificially created WSLs. Different strategies have been applied for the management of the artificially created WSLs. Six experimental groups were employed: Group I: sound enamel (control), Group II: demineralized enamel (artificially-created WSLs), Group III: ICON resin-treated WSLs, Group IV: CPP-ACP-treated WSLs, Group V: universal adhesive resin-treated WSLs, and Group VI: CPP-ACP followed by universal adhesive resin-treated WSLs. Assessment of color stability using a spectrophotometer, surface microhardness using a Vickers tester, and surface roughness using a profilometer was done. The surface topography of representative specimens from each experimental group was inspected using a scanning electron microscope. Collected data were analyzed using one-way ANOVA followed by Tukey's post hoc test at p ≤ 0.05. RESULTS: White spot lesions treated with CPP-ACP and subsequently coated with universal adhesive resin (Group VI) exhibited a significantly lower ΔE than both CPP-ACP (Group IV) and universal adhesive resin-treated (Group V) groups (p ≤ 0.05), but it was not significantly different from the ICON resin-treated group (Group III). For surface microhardness, WSLs treated with CPP-ACP and consequently coated with universal adhesive resin (Group VI) recorded the highest mean that was significantly different from both ICON resin (Group III) and universal adhesive resin-treated (Group V) groups (p ≤ 0.05). All the tested strategies (ICON resin, CPP-ACP, universal adhesive resin, and CPP-ACP followed by universal adhesive resin) significantly lowered the surface roughness of the WSLs (p ≤ 0.05), while no significant difference was detected among them. CONCLUSIONS: Combining a considerable caries remineralizing program using CPP-ACP with subsequent universal adhesive resin infiltration could be a promising approach to manage WSLs efficiently through increasing surface microhardness and restoring esthetic while developing a smoother surface.

Current herbal medicine as an alternative treatment in dentistry: In vitro, in vivo and clinical studies.

Since the time that human population comprehended the importance of general health maintenance and the burden of disease, there has been a search for healing properties in the natural environment. Herbal medicine is the use of plants with medical properties for prevention and treatment of conditions that can affect general health. Recently, a growing interest has been observed toward the use of traditional herbal medicine alongside synthetic modern drugs. Around 80% of the population, especially in developing countries relies on it for healthcare. Oral healthcare is considered a major part of general health. According to the world health organization (WHO), oral health is considered an important part of general health and quality of life. The utilization of natural medications for the management of pathologic oro-dental conditions can be a logical alternative to pharmaceutical methods due to their availability, low costs, and lower side effects. The current literature review aimed at exploration of the variety and extent of herbal products application in oral health maintenance including different fields of oral healthcare such as dental caries, periodontal maintenance, microbial infections, oral cancers, and inflammatory conditions.

Farnesal-loaded pH-sensitive polymeric micelles provided effective prevention and treatment on dental caries.

BACKGROUND: Farnesol is a sesquiterpene from propolis and citrus fruit that shows promising anti-bacterial activity for caries treatment and prevention, but its hydrophobicity limits the clinical application. We aimed to develop the novel polymeric micelles (PMs) containing a kind of derivative of farnesol and a ligand of pyrophosphate (PPi) that mediated PMs to adhere tightly with the tooth enamel. RESULTS: Farnesal (Far) was derived from farnesol and successfully linked to PEG via an acid-labile hydrazone bond to form PEG-hyd-Far, which was then conjugated to PPi and loaded into PMs to form the aimed novel drug delivery system, PPi-Far-PMs. The in vitro test about the binding of PPi-Far-PMs to hydroxyapatite showed that PPi-Far-PMs could bind rapidly to hydroxyapatite and quickly release Far under the acidic conditions. Results from the mechanical testing and the micro-computed tomography indicated that PPi-Far-PMs could restore the microarchitecture of teeth with caries. Moreover, PPi-Far-PMs diminished the incidence and severity of smooth and sulcal surface caries in rats that were infected with Streptococcus mutans while being fed with a high-sucrose diet. The anti-caries efficacy of free Far can be improved significantly by PPi-Far-PMs through the effective binding of it with tooth enamel via PPi. CONCLUSIONS: This novel drug-delivery system may be useful for the treatment and prevention of dental caries as well as the targeting therapy of anti-bacterial drugs in the oral disease.

Influence of green tea extract in the color of composite resin restorations.

The aim of this study was to evaluate the color change of composite resin restorations in Class I cavity preparation with different depths, submitted to challenge of thermocycling in coffee, after the use of green tea extract (EGCG) as treatment on the dentin surface. Forty-eight human molars were divided into 6 groups according to dentin treatment and depth of restoration (n = 8): Group C3- Control/3 mm; Group C4- Control/4 mm; Group C5- Control/5 mm; Group EGCG3- EGCG/3 mm; Group EGCG4- EGCG/4 mm; and Group EGCG5- EGCG/5 mm. The teeth of the control groups were restored by the bulk fill technique (Filtek Bulk Fill), conditioning the dentin surface only with universal bonding system (Single Bond Universal). The teeth of the EGCG groups were also restored by the bulk filling technique, but conditioning the dentin surface with 0.5% EGCG for 30 s prior to the application of the adhesive system. Initial and final color readings were performed according to the CIE L*a*b* scale in UV-2450 spectroscope, before and after challenge of thermal cycling in coffee. The color change (ΔE) was then calculated based on the formula ΔE = [(ΔL*)2+(Δa*)2+(Δb*)2]½. The ΔE data were submitted to statistical tests of normality, two-way ANOVA and Tukey test to compare the means (p < 0.05). There was no statistically difference for both study factors analyzed (EGCG application and restoration depth), as well as the interaction between both, after aging in coffee (p > 0.05). It was concluded that the previous application of EGCG did not cause a significant color change at the dentin-resin interface.

Oral health and diet of a young Late Pleistocene woman from Quintana Roo, Mexico.

OBJECTIVES: To increase understanding of the subsistence practices of the first Americans through analysis of the near-complete dentition of a young woman dating to the terminal Pleistocene of the Yucatan Peninsula, Mexico. MATERIALS AND METHODS: The skeleton is that of "Naia" a 15 to 17-year-old female from the submerged natural trap of Hoyo Negro found in association with remains of numerous extinct species of megafauna. Superbly preserved remains included the skull with 28 teeth, which are analyzed for evidence of caries, periodontal disease, wear patterns, and malocclusion. RESULTS: Naia exhibits a high frequency of dental caries, along with aggressive periodontal disease that threatened all her teeth, particularly her incisors. Dental attrition was extremely light for a hunter-gatherer, reaching to four on the Molnar scale on only one tooth. Lack of wear is associated with severe mandibular retrognathia, and low masticatory forces. DISCUSSION: Naia's dental condition is compared with that of other northern Paleoamericans, mostly females, dating before 11,000 cal BP. These exhibit a high degree of variability in both caries and tooth wear. All, however, exhibit rapid anterior wear owing to technological use of the front teeth. Naia exhibits the highest rate of caries, similar to that of the earliest South Americans, and one of the lowest rates of attrition. This demonstrates that she had a nonabrasive diet that was at least seasonally rich in carbohydrates. This does not mean her diet was low in meat, however, because similarly light dental attrition is seen in the Arch Lake female, a Paleoamerican from a big-game hunting society.

Assessing subsistence and its relationship to cultural complexity in the late prehistoric upper Midwest: A new perspective provided by dental health.

OBJECTIVE: Previous researchers have assumed that the Late Prehistoric Oneota were less reliant on maize agriculture than their Middle Mississippian neighbors to the south. This assumption is based on the idea that intensive maize agriculture is related to sociopolitical complexity, and that the climate of the Great Lakes region was less conducive to full-scale agriculture than that of the American Bottom. Here, we assess the diet of the Oneota using dental pathology to test the hypothesis that the Oneota in Eastern Wisconsin were highly reliant on maize agriculture. MATERIALS AND METHODS: To test our hypothesis, skeletal remains representing 187 individuals and 1,102 teeth were examined from nine Oneota sites from the Middle Fox and Koshkonong Localities, as well as the Late Woodland/Middle Mississippian site of Aztalan. Dental caries, antemortem tooth loss (AMTL), and dental abscesses were assessed for each individual in the sample. Dental pathologies in the Oneota groups were compared to each other based on Locality and to the Aztalan population using chi-squared tests. RESULTS: Dental caries rates for the Oneota, based on the tooth count approach, were observed at 16.8% for the Middle Fox Locality, and 49% for the Koshkonong Locality. Comparatively, the Late Woodland/Middle Mississippian population from Aztalan had a tooth count rate of 19.5%. AMTL rates were similar across samples. Dental abscessing was universally low. DISCUSSION: The relatively high rate of dental caries among the Oneota is comparable to Middle Mississippian populations from throughout the Midwest, suggesting similar reliance on maize between the groups.

Propolis and its Dental Applications: A Technological Prospection.

BACKGROUND: Propolis is a resinous complex produced by Apis mellifera L. bees whose variety of pharmacological properties results from the complexity of its composition. In dentistry, propolis is used on the prevention of oral diseases such as dental caries and gingivitis. Prospective studies in intellectual property banks are important to increase market competitiveness and thus generate new products in the various research areas. In this way, investments in patents play an important role in the technological and economic development of a country. OBJECTIVE: To evaluate patents with dental products containing propolis, on intellectual property banks. METHOD: The research was conducted in 10 banks of intellectual property, including since the first deposits up to 2016. Relevant information that describes the invention in the patent document were collected, processed and described. RESULTS: The search performed in 62 patents using propolis in the dental topic. World Intellectual Property Organization (WIPO) has the largest number of filing patents (83.60%) and the National Institute of Industrial Property (INPI) in third place with 4 patents (6.55%). Built-in dental cream with propolis was the most patented product. The first patent date of 1998, followed by an increase in the number of deposits in the last 20 years. Most of the patents are A61K code (51) for medical, dental or hygienic purposes. CONCLUSION: This study has shown that propolis is a promising bioactive component in dental products, especially for use in Cariology and Periodontology. Although there has been a significant progress in applications of propolis, the field of dental products is still a growing area and it is important to encourage innovation and development of new products incorporating propolis based on knowledge of its composition and therapeutic properties.

Earliest evidence of caries lesion in hominids reveal sugar-rich diet for a Middle Miocene dryopithecine from Europe.

The formation of dental caries is mainly caused by dietary habits and therefore, may contain information for dietary reconstructions of fossil hominids. This study investigates the caries lesion in the 12.5 Ma old type specimen of Dryopithecus carinthiacus Mottl 1957 (Primates, Hominidae) from St. Stefan (Austria). Potential food sources are identified on associated palynological data, which allow conclusions about food quality, sugar availability and the hominid metabolism during the Middle Miocene. Using micro computed tomography (µCT) and scanning electron microscopy (SEM) we provide a detailed analysis and characterization of the individuals' caries type. Its lesion is compared with a dataset of 311 wild chimpanzees, indicating morphological and etiological differences in caries formation between both species. The affected molar of D. carinthiacus reveals features known from severe dental caries in humans: (1) Cavitation with steep walls and smooth surface; (2) Reparative dentine at the roof of the pulp chamber; (3) Sclerotic dentine below the cavitation; (4) Association with dental calculus and (5) Unilateral usage of the healthy right tooth row. Its advanced primary caries, initiating on the intact enamel surface, indicates a frequent intake of highly cariogenic sugar-rich fruits, which likely exceeds the frugivory of extant chimpanzees. This finding corresponds with the associated palynological record, which infers a habitat with nearly year-round supply (9-10 months/year) of high quality foods (>carbohydrates; < fibers). Our conclusions challenge the model of a step-wise increase in dietary quality during hominid evolution and support the uricase hypothesis, which discusses the hominid autapomorphy of a fructose-based fat accumulation for periods of starvation. This model receives further validation by the identification of soft-tissue preservation, interpreted as fossilized white adipose cells, in the articulated hominid skeleton of Oreopithecus bamboli from Italy.

Remineralisation of enamel white spot lesions pre-treated with chitosan in the presence of salivary pellicle.

OBJECTIVE: To investigate the remineralisation of chitosan pre-treated enamel white spot lesions (WSLs) by bioglass in the presence of the pellicle layer. METHODS: 50 artificial enamel white spot lesions were created by acidic gel. Two lesions were used to investigate the formation of the pellicle layer by treating with human whole saliva for 3 min. 48 lesions were assigned to 6 experimental groups (n = 8): (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) "standard" remineralisation solution (RS) and (6) de-ionised water (negative control, NC). Remineralisation was carried out using a pH-cycling model for 7 days. Before each treatment using remineralising agents, 3-min pellicle was formed on lesions' surfaces. Mineral content changes, surface and subsurface microhardness and ultrastructure were evaluated by Raman intensity mapping, Knoop microhardness and scanning electron microscopy, respectively. Data were statistically analysed using one-way ANOVA with Tukey's test (p < 0.05 is considered as significant). RESULTS: Despite the heterogeneously formed pellicle layer, all groups showed an increase in surface mineral content after pH-cycling. Chitosan pre-treatment enhanced the subsurface remineralisation of WSLs using bioglass as both pre-treated groups showed greater surface and subsurface microhardness compared to NC. CS-BG exhibited denser subsurface structure than BG, while in CS-BG + PAA the crystals were bigger in size but resemble more enamel-like compared to BG + PAA as shown in SEM observations. Remineralisation of RS was limited to the surface as no significant subsurface changes of mechanical properties and structure were found. CONCLUSIONS: Chitosan pre-treatment can enhance WSL remineralisation with bioglass biomaterials when a short-term salivary pellicle is present. A further investigation using a long-term pH-cycling model with mature pellicle is suggested with regards to clinical application. CLINICAL SIGNIFICANCE: Chitosan pre-treatment has the potential in clinical application to remineralise subsurface lesions to achieve lesion consolidation.

The dawn of dentistry in the late upper Paleolithic: An early case of pathological intervention at Riparo Fredian.

OBJECTIVES: Early evidence for the treatment of dental pathology is found primarily among food-producing societies associated with high levels of oral pathology. However, some Late Pleistocene hunter-gatherers show extensive oral pathology, suggesting that experimentation with therapeutic dental interventions may have greater antiquity. Here, we report the second earliest probable evidence for dentistry in a Late Upper Paleolithic hunter-gatherer recovered from Riparo Fredian (Tuscany, Italy). MATERIALS AND METHODS: The Fredian 5 human consists of an associated maxillary anterior dentition with antemortem exposure of both upper first incisor (I1 ) pulp chambers. The pulp chambers present probable antemortem modifications that warrant in-depth analyses and direct dating. Scanning electron microscopy, microCT and residue analyses were used to investigate the purported modifications of external and internal surfaces of each I1 . RESULTS: The direct date places Fredian 5 between 13,000 and 12,740 calendar years ago. Both pulp chambers were circumferentially enlarged prior to the death of this individual. Occlusal dentine flaking on the margin of the cavities and striations on their internal aspects suggest anthropic manipulation. Residue analyses revealed a conglomerate of bitumen, vegetal fibers, and probable hairs adherent to the internal walls of the cavities. DISCUSSION: The results are consistent with tool-assisted manipulation to remove necrotic or infected pulp in vivo and the subsequent use of a composite, organic filling. Fredian 5 confirms the practice of dentistry-specifically, a pathology-induced intervention-among Late Pleistocene hunter-gatherers. As such, it appears that fundamental perceptions of biomedical knowledge and practice were in place long before the socioeconomic changes associated with the transition to food production in the Neolithic.

Promotion of enamel caries remineralization by an amelogenin-derived peptide in a rat model.

OBJECTIVE: An amelogenin-derived peptide has been shown to promote remineralization of demineralized enamel in an in vitro model of initial caries induced by pH cycling. The present study examines whether the peptide exerts similar effects within the complex oral environment in vivo. DESIGN: Specific pathogen-free Sprague-Dawley rats (n=36) were infected with Streptococcus mutans, given ad libitum access to Diet 2000 and drinking water supplemented with sucrose (10%, w/v), and then randomly divided into three groups treated with 25µM peptide solution, 1g/L NaF or deionized water. Molar teeth were swabbed twice daily with the respective solutions for 24days. Then animals were killed, their jaws were removed and caries lesions were analyzed using the quantitative light-induced fluorescence-digital (QLF-D) technique to measure changes in mineral content. To verify QLF-D results, caries were scored for lesion depth and size using the Keyes method, and analyzed using polarized light microscopy (PLM). RESULTS: Mineral gain was significantly higher in teeth treated with peptide or NaF than in teeth treated with water (p<0.05), based on the QLF-D results (ΔF and ΔQ). Incidence of smooth-surface and sulcal caries based on Keyes scores was similar in rats treated with peptide or NaF, and significantly lower in these groups than in rats treated with water (p<0.05). Lesions on teeth treated with peptide or NaF were shallower, based on PLM. No significant differences were observed between molar enamel caries treated with peptide or NaF. CONCLUSIONS: This amelogenin-derived peptide can promote remineralization in a rat caries model, indicating strong potential for clinical use.

Histochemical changes of occlusal surface enamel of permanent teeth, where dental caries is questionable vs sound enamel surfaces.

AIM: This in vitro study was to classify questionable for caries occlusal surfaces (QCOS) of permanent teeth according to ICDAS codes 1, 2, and 3 and to compare them in terms of enamel mineral composition with the areas of sound tissue of the same tooth. METHODS: Partially impacted human molars (60) extracted for therapeutic reasons with QCOS were used in the study, photographed via a polarised light microscope and classified according to the ICDAS II (into codes 1, 2, or 3). The crowns were embedded in clear self-cured acrylic resin and longitudinally sectioned at the levels of the characterised lesions and studied by SEM/EDX, to assess enamel mineral composition of the QCOS. Univariate and multivariate random effect regressions were used for Ca (wt%), P (wt%), and Ca/P (wt%). RESULTS: The EDX analysis indicated changes in the Ca and P contents that were more prominent in ICDAS-II code 3 lesions compared to codes 1 and 2 lesions. In these lesions, Ca (wt%) and P (wt%) concentrations were significantly decreased (p = 0.01) in comparison with sound areas. Ca and P (wt%) contents were significantly lower (p = 0.02 and p = 0.01 respectively) for code 3 areas in comparison with codes 1 and 2 areas. Significantly higher (p = 0.01) Ca (wt%) and P (wt%) contents were found on sound areas compared to the lesion areas. CONCLUSIONS: The enamel of occlusal surfaces of permanent teeth with ICDAS 1, 2, and 3 lesions was found to have different Ca/P compositions, necessitating further investigation on whether these altered surfaces might behave differently on etching preparation before fissure sealant placement, compared to sound surfaces.

Dentin Topographic Features following Chemomechanical Caries Removal in Primary Teeth.

AIM: Study the topographic features of dentin after caries removal with a chemomechanical agent (Papacarie) compared with the conventional drilling method. STUDY DESIGN: The sample included 7 exfoliated and extracted primary teeth with carious dentin lesions, not reaching the pulp. Each tooth was sectioned longitudinally through the center of the carious lesions into two halves. The teeth were then divided into two groups according to the method of caries removal. Following caries removal, dentin topography and the cut section were examined using the scanning electron microscope. RESULTS: Papacarie produced an irregular, porous, rough and globular dentin appearance. The dentin surfaces were generally free of smear layer, visible bacteria and the dentinal tubules were opened. The dentin cut surfaces showed patent dentinal tubules with open orifices. The drilling method created a smooth and amorphous surface with a continuous smear layer occluding the dentinal tubules. Numerous bacteria were also observed. The cut dentin surfaces showed patent dentinal tubules with their orifices plugged with smear layer. CONCLUSIONS: Papacarie produced a rough and porous surface with partial or complete removal of the smear layer and opened dentinal tubules, while the drill produced a smooth surface with uniform smear layer occluding the dentinal tubules.

Effect of LongZhang Gargle on Biofilm Formation and Acidogenicity of Streptococcus mutans In Vitro.

Streptococcus mutans, with the ability of high-rate acid production and strong biofilm formation, is considered the predominant bacterial species in the pathogenesis of human dental caries. Natural products which may be bioactive against S. mutans have become a hot spot to researches to control dental caries. LongZhang Gargle, completely made from Chinese herbs, was investigated for its effects on acid production and biofilm formation by S. mutans in this study. The results showed an antimicrobial activity of LongZhang Gargle against S. mutans planktonic growth at the minimum inhibitory concentration (MIC) of 16% and minimum bactericidal concentration (MBC) of 32%. Acid production was significantly inhibited at sub-MIC concentrations. Biofilm formation was also significantly disrupted, and 8% was the minimum concentration that resulted in at least 50% inhibition of biofilm formation (MBIC50). A scanning electron microscopy (SEM) showed an effective disruption of LongZhang Gargle on S. mutans biofilm integrity. In addition, a confocal laser scanning microscopy (CLSM) suggested that the extracellular polysaccharides (EPS) synthesis could be inhibited by LongZhang Gargle at a relatively low concentration. These findings suggest that LongZhang Gargle may be a promising natural anticariogenic agent in that it suppresses planktonic growth, acid production, and biofilm formation against S. mutans.

Severe childhood caries associated with iron deficiency anemia: a case report.

This case showed an association between caries and anemia in a 3-year-old boy, whose crowns were destroyed by caries. Tests showed a low hematocrit as well as low levels of hemoglobin, ferritin, and serum iron. Impaired growth and delayed neuropsychomotor development were observed. The child was hospitalized for antibiotic administration, blood transfusion, multiple dental extractions, and iron supplementation. He was discharged after 20 days, when anemia and oral infection were resolved.

Galla chinensis Compounds Remineralize Enamel Caries Lesions in a Rat Model.

OBJECTIVES: To investigate the effect of Galla chinensis chemical compounds on enamel caries remineralization in rats. METHODS: A total of 40 rats were inoculated with Streptococcus sobrinus 6715 and fed a cariogenic diet (Keyes 2000). The rats were randomly divided into 4 groups and treated topically twice a day with each of the following extracts (or control) for 5 weeks: distilled and deionized water (DDW, negative control); 1,000 ppm NaF (positive control); 4,000 ppm G. chinensis crude aqueous extract (GCE), or 4,000 ppm gallic acid (GA). After the experimental period, Keyes' caries diagnosis and scoring technique was applied as a preliminary evaluation on the molar teeth. For more accurate remineralization data, the residual enamel volume of the first molar and the mineral density (MD) of the enamel were further analyzed by micro-CT. RESULTS: The severity of molar enamel caries decreased in the following order of treatment groups: DDW > GA > GCE > NaF (p < 0.05). In addition, the residual first molar enamel volume and MD values increased in the order of DDW, GA, GCE and NaF treatment groups (p < 0.05). In most molars, remineralization layers were observed on the surface of lesions. CONCLUSION: G. chinensis compounds remineralize enamel caries lesions in a rat model.

Clinical, mineral and ultrastructural changes in carious dentin of primary molars after restoration.

INTRODUCTION: Partial caries removal has been shown to be an effective method to treat deep carious lesions in deciduous teeth. Nevertheless, the possibility of keeping infected dentin in the cavity still requires additional investigation. The objective of this research was to describe changes in primary infected dentin after restoration with glass ionomer cement. METHODS: Dentin from 45 primary molars with deep and active carious lesions was evaluated using clinical and laboratory criteria, before and 60 days after restoration. The clinical analysis evaluated dentin colour (CO), dentin consistency (COS) and laser fluorescence (LF). The laboratory procedures assessed bacterial contamination and mineral content (MC), and evaluated the dentin ultrastructure and collagen content. Data on CO, COS, LF and colony forming units were analysed using the Wilcoxon signed-rank test; MC, bacterial counts and collagen evaluations were evaluated using the Student's t-test. RESULTS: After 60 days, lower values of LF were observed, together with a lower bacterial count, and a higher COS was found, with an increase in calcium, phosphorus and collagen contents. Differences were not detected for CO or for fluorine content. Baseline samples showed enlarged tubules with bacterial invasion; 60-day samples showed better organised tissue, with a more compact intertubular dentin and narrower tubules. CONCLUSION: It is concluded that appropriate cavity sealing can promote beneficial changes in deep carious lesions of primary teeth, even in the presence of infected dentin.

Chemical and Morphological Changes of Primary Teeth Irradiated with Nd:YAG Laser: An Ex Vivo Long-Term Analysis.

OBJECTIVE: The aim of this study was to assess any long-term chemical and morphological Nd:YAG laser modifications on irradiated primary enamel. BACKGROUND DATA: Previous studies on irradiated primary human enamel employed methodologies that evaluated the short-term effects only. METHODS: One hundred and eighty-six irradiated (with and/or without fluoride) primary enamel teeth from high-caries-risk children, which were exfoliated over a 1-year period, were collected, and the sample surface area was submitted for scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray energy-dispersive spectrometry (EDS). The subsurface was analyzed by Knoop microhardness and light microscopy (LM). Data were analyzed by one way ANOVA and Tukey tests (α=0.05) and Kruskall-Wallis and Tukey tests (α=0.05). RESULTS: FTIR analysis revealed a higher concentration of phosphate and carbonate in the irradiated (0.987±0.064) and lower concentration in the control groups (1.477±0.310). SEM analysis showed that the control samples exhibited a slightly smoother surface than the irradiated groups. The EDS analysis did not show any differences in the amount of calcium, phosphorus, or fluoride among the groups. The microhardness analysis revealed that sealant (249.86±7.15) and laser irradiation (262.44±22.69) led to higher hardness values than the negative control group (128.35±25.19). LM indicated significantly reduced caries formation in the laser (5.35±5.38%) and the laser plus acidulated phosphate fluoride (APF) groups (10.35±0.88%) compared with the negative control group (72.56±12.86%). CONCLUSIONS: Even with the limitations of the present study, these results suggest that Nd:YAG irradiation clinically modified the chemical composition of the enamel surface regardless of fluoride concentration, which successfully inhibited demineralization of primary tooth enamel over a 1-year period without significant morphological changes.

The role of glass ionomer cement on the remineralization of infected dentin: an in vivo study.

PURPOSE: This study's purpose was to investigate the effect of a glass ionomer cement as a liner over infected unexcavated dentin after 60 days and at 10 to 15 months. METHODS: Forty-five permanent molars with deep carious lesions were selected. Fragments of carious dentin were removed prior to lining the cavity (baseline sample) with glass ionomer cement (G1) or an inert wax material (G2). Cavities were restored with composite resin and reopened 60 days later, when other fragments were removed (60-day sample). The dentin morphology (scanning electron microscopy) and mineral content of calcium, phosphorus, and fluorine were assessed. During the follow-up periods (60 days and 10 to 15 months), restorations were evaluated and standardized radiographs were taken. A postprocessing routine was used to identify changes in the radiographic density between periods. RESULTS: After 60 days, the dentin exhibited a better organization, fewer bacteria, and signs of remineralization. The weight percents of calcium and phosphorus were higher 60 days after the cavity sealing, regardless of the group. Higher gray levels of carious and sound dentin were seen on the 10- to 15-month radiographs, irrespective of the group. The success rates of G1 and G2 were 89 percent and 88 percent, respectively. CONCLUSIONS: The lining material isn't fundamental for caries arrestment. Early (60-day) and late (10 to 15 months) dentin changes occurred, indicating the remineralization of dentin carious tissue.