Modulating stemness of mesenchymal stem cells from exfoliated deciduous and permanent teeth by IL-17 and bFGF.

Mesenchymal stem cells (MSCs) have been identified within dental pulp tissues of exfoliated deciduous (SHEDs) and permanent (DPSCs) teeth. Although differences in their proliferative and differentiation properties were revealed, variability in SHEDs and DPSCs responsiveness to growth factors and cytokines have not been studied before. Here, we investigated the influence of interleukin-17 (IL-17) and basic fibroblast growth factor (bFGF) on stemness features of SHEDs and DPSCs by analyzing their proliferation, clonogenicity, cell cycle progression, pluripotency markers expression and differentiation after 7-day treatment. Results indicated that IL-17 and bFGF differently affected SHEDs and DPSCs proliferation and clonogenicity, since bFGF increased proliferative and clonogenic potential of both cell types, while IL-17 similarly affected SHEDs, exerting no effects on adult counterparts DPSCs. In addition, both factors stimulated NANOG, OCT4, and SOX2 pluripotency markers expression in SHEDs and DPSCs showing diverse intracellular expression patterns dependent on MSCs type. As for the differentiation capacity, both factors displayed comparable effects on SHEDs and DPSCs, including stimulatory effect of IL-17 on early osteogenesis in contrast to the strong inhibitory effect showed for bFGF, while having no impact on SHEDs and DPSCs chondrogenesis. Moreover, bFGF combined with IL-17 reduced CD90 and stimulated CD73 expression on both types of MSCs, whereas each factor induced IL-6 expression indicating its' role in IL-17/bFGF-modulated properties of SHEDs and DPSCs. All these data demonstrated that dental pulp MSCs from primary and permanent teeth exert intrinsic features, providing novel evidence on how IL-17 and bFGF affect stem cell properties important for regeneration of dental pulp at different ages.

Regulation of the regenerative activity of dental pulp stem cells from exfoliated deciduous teeth (SHED) of children by TGF-ß1 is associated with ALK5/Smad2, TAK1, p38 and MEK/ERK signaling.

Transforming growth factor-ß1 (TGF-ß1) regulates wound healing/regeneration and aging processes. Dental pulp stem cells from human exfoliated deciduous teeth (SHED) are cell sources for treatment of age-related disorders. We studied the effect of TGF-ß1 on SHED and related signaling. SHED were treated with TGF-ß1 with/without pretreatment/co-incubation by SB431542, U0126, 5Z-7-oxozeaenol or SB203580. Sircol collagen assay, 3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyl tetrazolium bromide (MTT) assay, alkaline phosphatase (ALP) assay, RT-PCR, western blotting and PathScan phospho-ELISA were used to measure the effects. We found that SHED expressed ALK1, ALK3, ALK5, TGF-RII, betaglycan and endoglin mRNA. TGF-ß1 stimulated p-Smad2, p-TAK1, p-ERK, p-p38 and cyclooxygenase-2 (COX-2) protein expression. It enhanced proliferation and collagen content of SHED that were attenuated by SB431542, 5Z-7-oxozeaenol and SB203580, but not U0126. TGF-ß1 (0.5-1 ng/ml) stimulated ALP of SHED, whereas 5-10 ng/ml TGF-ß1 suppressed ALP. SB431542 reversed the effects of TGF-ß1. However, 5Z-7-oxozeaenol, SB203580 and U0126 only reversed the stimulatory effect of TGF-ß1 on ALP. Four inhibitors attenuated TGF-ß1-induced COX-2 expression. TGF-ß1-stimulated TIMP-1 and N-cadherin was inhibited by SB431542 and 5Z-7-oxozeaenol. These results indicate that TGF-ß1 affects SHED by differential regulation of ALK5/Smad2/3, TAK1, p38 and MEK/ERK. TGF-ß1 and SHED could potentially be used for tissue engineering/regeneration and treatment of age-related diseases.

Protective factors for caries of a school-based oral health program in Bangkok, Thailand: a retrospective cohort study.

OBJECTIVES: The aim of the study was to assess protective factors of a school-based oral health preventive program on caries in permanent teeth in students and to identify other risk and protective factors associated with caries in this group. STUDY DESIGN: This is a retrospective cohort study. METHODS: A total of 433 students were examined in the 1st grade and followed up until the 6th grade. Each student was annually assessed for caries as per the World Health Organization index. Binary simple and multiple logistic regressions were performed to assess risk or protective factors with a P-value ≤0.05. RESULTS: In 1st graders, the caries prevalence in deciduous teeth was 87.2%, and the mean decayed, missing and filled teeth (dmft) index was 6.44 (±4.4); in 6th graders, the caries prevalence in permanent teeth was 51.7%, and the mean DMFT was 1.37 (±1.84). Protective factors for caries in permanent teeth were complete participation in the program, receiving fluoride varnish >4 times, and sealant applications on all first molars. Risk factors were female sex and caries prevalence in deciduous teeth. After multiple logistic regression, sealant application only remained significant, with an odds ratio (OR) of 0.19 (95% confidence interval [CI] = 0.06-0.63, P = 0.007), and for risk factor, caries prevalence in deciduous teeth only remained significant, with an OR of 5.44 (95% CI = 2.23-13.27, P < 0.001). CONCLUSIONS: There is an association between deciduous dentition caries and permanent dentition caries. Early prevention in school settings by applying fluoride varnish and dental sealants onto molars is protective and feasible. The study suggests that regular fluoride varnish and sealant applications should be extended to similar low-income area schools.

Preventing early childhood caries with silver diamine fluoride: study protocol for a randomised clinical trial.

BACKGROUND: Silver diamine fluoride (SDF) solution is effective in arresting early childhood caries (ECC). Previous studies have suggested that it might exert a preventive effect in managing ECC. However, no well-designed clinical trials have yet been performed to study the effect of SDF on caries prevention. The objective of this randomised clinical trial is to determine whether 38% SDF solution is superior to 5% sodium fluoride (NaF) varnish in preventing new carious lesions in primary anterior teeth. METHODS/DESIGN: This is a phase II, single-centre, randomised, double-blind, active-controlled, parallel-group pragmatic trial. The hypothesis tested is that 38% SDF would be more effective than 5% NaF in preventing new caries development in primary anterior teeth. Approximately 730 3-year-old children who are generally healthy and with parental consent will be recruited from Hong Kong kindergartens. This sample size will be sufficient for appropriate statistical analysis of a superiority trial with 90% power, allowing for a 20% drop-out rate. Stratified randomisation will be adopted for allocating the intervention. The intervention will either be 38% SDF or 5% NaF (as a positive control) therapy on primary upper anterior teeth. A single trained examiner will conduct a dental examination every 6 months until 30 months in kindergarten. Another operator will provide fluoride therapy immediately after each dental examination. The examiner, children and children's parents will be blinded to the treatment allocation. A questionnaire survey will be conducted to study the children's oral health-related behaviours and socioeconomic backgrounds. Chi-square tests, t tests, regression analyses and survival analyses will be adopted for data analysis. DISCUSSION: The effectiveness of 38% SDF in preventing ECC remains uncertain. If the results are as anticipated, care standards using 5% NaF for ECC prevention will be changed. In addition, the results will be widely available and increase the adoption of SDF in other countries to reduce the global burden of ECC. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04075474. Registered on 30 Aug 2019.

Randomized controlled clinical trial of resin infiltration in primary molars: 2 years follow-up.

OBJECTIVE: The aim of this split-mouth, randomized, controlled clinical trial was to evaluate the efficacy of resin infiltration in controlling the progression of non-cavitated proximal lesions in primary molars after two-years follow-up. METHODS: Fifty healthy children presenting at least two primary molars with proximal lesion detected radiographically (in the inner half of enamel or the outer third of dentin) were included in the study. The proximal lesions were randomly allocated into resin infltration + flossing (test group) or flossing (control group). All patients received oral hygiene instructions for daily brushing with fluoride toothpaste (1100 ppmF) and flossing. The proportion of caries progression was compared using the McNemar test. The main outcome after 2-years, caries progression in the radiography was assessed by pair-wise reading by an independent examiner who was blind regarding the treatment. RESULTS: The sample comprised 28 (56%) girls and 22 (44%) boys with a defs of 7,3 (SD = 6,5), mainly of moderate (46%) to high (48%) caries risk. Results after one year were published previously. After 2-years, 29 (58%) patients were assessed. Caries progression was observed in 24.1% (7/29) of the test lesions, compared with 55.2% (16/29) of the control lesions (p = 0.012). The therapeutic effect was 31.1% and the relative risk reduction (RRR) was 56.3%. Eigth lesions from the control group and two lesions from the test group progressed to the inner third of dentin and were restored. CONCLUSIONS: In conclusion, resin infiltration was more efficacious in controlling proximal caries lesions in primary molars than non-invasive approach alone. CLINICAL SIGNIFICANCE: The results indicate that resin infiltration was an efficacious method in controlling proximal caries lesions in primary molars after 2 years, even in patients with high caries risk, reaffirming the results of 1-year follow-up.

Efficacy of 30% silver diamine fluoride compared to atraumatic restorative treatment on dentine caries arrestment in primary molars of preschool children: A 12-months parallel randomized controlled clinical trial.

OBJECTIVES: This clinical trial investigated the efficacy of silver diamine fluoride (SDF) in arresting dentine caries in primary molars of preschoolers. Time required for treatment, adverse effects, parental aesthetic perception, anxiety and oral health related to quality of life (OHRQoL) was evaluated. MATERIALS AND METHODS: Children, 2-5 years old, with active dentine caries lesions on the occlusal surface of primary molars were randomly allocated to test group (SDF) or control group (atraumatic restorative treatment/ART). The dmf-t/DMF-T and ICDAS indexes determined the presence of caries and activity. The main outcome after 3, 6 and 12-month follow-up was assessed by a blind examiner. The time required to perform the treatments was recorded and a facial image scale was applied to assess anxiety before and after treatment. Adverse events and aesthetic perception were assessed through questions addressed to caregivers; and the OHRQoL through the B-ECOHIS questionnaire. RESULTS: In 68 patients that were randomized, the mean number of treated teeth per child was 2.42(1.04) and 2.09(1.18) in the SDF and ART groups (p = 0.074), respectively. The mean difference of arrested lesions between the groups after 12 months was -0,07(0.05; - 0.17-0.30). The time required to treat with SDF was lower than the ART (p < 0.001). There was no difference in the percentage of adverse events + aesthetic perception (p = 0.709), and the change in anxiety (p = 0.155). There was a less impact in OHRQoL after ART treatment, but only when the parents' distress subscale was considered (p = 0.012). CONCLUSION: SDF requires much less chair-time and have similar results as ART in arresting caries lesion, anxiety, adverse effects, aesthetic perception and quality of life.

Protective effect of folic acid on vulnerability to oxidative stress in dental pulp stem cells of deciduous teeth from children with orofacial clefts.

Orofacial clefts (OFCs) are among the most common congenital craniofacial malformations, including cleft lip with or without cleft palate as the core symptoms. Developmental or functional defects in neural crest cells (NCCs) that contribute to craniofacial morphogenesis are involved in OFC development. Previous studies have suggested that oxidative stress in NCCs is involved in the development of OFCs, suggesting that the anti-oxidative activity of folic acid (FA) could have protective effects. However, studies of human-derived NCCs are limited, as these cells are predominantly active during the embryonic stage. In this study, the effects of oxidative stress and FA were evaluated in human OFCs. In particular, NCC-derived stem cells from human exfoliated deciduous teeth (SHEDs) were obtained from 3 children with non-syndromic cleft lip with cleft palate (CLPs) and from 3 healthy children (CTRLs). Mitochondrial reactive oxygen species (ROS) levels were significantly higher in CLPs than in CTRLs and were associated with lower mRNA expression levels of superoxide dismutase 1 (SOD1) and decreased cell mobility. In addition, significantly greater vulnerability to pyocyanin-induced ROS, mimicking exogenous ROS, was observed in CLPs than in CTRLs. These vulnerabilities to endogenous and exogenous ROS in CLPs were significantly improved by FA. These results indicated that the transcriptional dysregulation of SOD1 in NCCs is an oxidative stress-related pathological factor in OFCs, providing novel evidence for the benefits of perinatal anti-oxidant supplementation, including FA, for the management of these common deformities.

Efficacy of diode and CO2 lasers along with calcium and fluoride-containing compounds for the remineralization of primary teeth.

BACKGROUND: This study aimed to assess the efficacy of a 980-nm diode and 10.6-µm CO2 laser accompanied by tricalcium phosphate-5% sodium fluoride (fTCP) and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) for the remineralization of primary teeth. METHODS: In total, 117 extracted primary anterior teeth were randomly divided into eight experimental and one control group: (I) control (polished enamel), (II) fTCP varnish, (III) fTCP + diode laser, (IV) fTCP + CO2 laser, (V) CPP-ACP, (VI) CPP-ACP + diode laser, (VII) CPP-ACP + CO2 laser, (VIII) diode laser, and (IX) CO2 laser. The microhardness of 12 samples in each group and the enamel porosity of one sample in each group were assessed before and after demineralization and 28 days after remineralization. Data were analysed using two-way ANOVA. RESULTS: Significant differences existed in microhardness (P = 0.004) and percentage of remineralization (P < 0.001) after remineralization among the material groups such that the highest mean was noted in the CPP-ACP group. No significant difference was noted in microhardness (P = 0.052) or percentage of remineralization (P = 0.981) after remineralization among the laser groups. In all groups, porosities increased after demineralization and slightly decreased after remineralization; the greatest reduction in porosity of the material groups was noted in the fTCP group, and the CO2 group among the laser groups. The interaction effect of materials and lasers was not significant (P > 0.05). CONCLUSION: The highest microhardness was achieved after remineralization with CPP-ACP. The efficacy of the diode and CO2 lasers was the same. No synergistic effect was found between materials and lasers. TRIAL REGISTRATION: This is not a human subject research.

Deproteinization of primary enamel with sodium hypochlorite before phosphoric acid etching.

The aim of this study was to evaluate the deproteinization of primary enamel by analyzing etching pattern types, with and without the application of 5% NaOCl before acid etching with 37% H3PO4. Fifteen extracted human primary molars were randomly selected for the present in vitro study; 1mm x 1mm blocks were prepared and divided into two groups (n = 21). These groups were treated as follows: Group A- Acid Etching with 37% H3PO4 gel for 15 s; Group B- 5% NaOCl for 60 s + Acid Etching with 37% H3POfor 15 s. The specimens were prepared for scanning electron microscopy analysis. The images were evaluated for quality types I and II etching of the enamel surface using ImageJ software. Datasets were checked for normality by Kolgomorv-Smirnov test and the nonparametric unpaired Mann-Whitney test was applied. The mean surface area of type I and II etching pattern values was 1922.314 µm2for Group A and 3840.473 µm2Group B. We conclude that deproteinization with 5% NaOCl prior to acid etching can be used to increase the area of adhesion and the quality of the etching pattern.

El objetivo del estudio fue evaluar la desproteinización del esmalte primario a través de los tipos de patrones de grabado, con y sin NaOCl 5% utilizado antes del grabado ácido con H3PO4 37%. Quince dientes primarios humanos extraídos se seleccionaron al azar para el presente estudio in vitro, se prepararon bloques de 1mm x 1 mm y se dividieron en dos grupos (n = 21). Estos grupos se trataron de la siguiente manera: Grupo A: Grabado ácido con H3PO4 37% en gel durante 15 segundos; Grupo B: NaOCl 5% durante 60 segundos + Grabado ácido con H3PO4 37% durante 15 segundos. Las muestras se prepararon para el análisis de microscopía electrónica de barrido. Las imágenes obtenidas se evaluaron principalmente por la calidad de los grabados tipo I y II de la superficie del esmalte primario, utilizando el software Image J. Los datos se analizaron en cuanto a su normalidad mediante la prueba de Kolgomorv-Smirnov, se utilizó pruebas no paramétricas: Prueba de Mann-Whitney no pareada. Como resultado, se encontró que el área de superficie media de los valores de patrón de grabado de tipo I y II para el Grupo A era 1922,314 µm2 y el Grupo B era 3840,473 µm2. Finalmente, llegamos a la conclusión de que se puede usar la desproteinización con NaOCl 5% antes del grabado ácido para aumentar el área de adhesión y la calidad del patrón de grabado.

In Vitro evaluation of the wear of primary tooth enamel against different ceramic and composite resin materials.

BACKGROUND: Although there are several studies on permanent tooth wear caused by dental materials, studies concerning primary teeth are limited. AIM: To evaluate the wear of primary tooth enamel against different ceramic and composite resin materials. SETTINGS AND DESIGN: In vitro study. Materials and Methods: We assessed five materials (n = 10 per group): monolithic zirconia (group Z), lithium disilicate glass ceramic (group L), resin nanoceramic (group R), nanohybrid composite resin (group C), and primary tooth enamel (group E). The mesiopalatal cusps of primary maxillary second molars were used as antagonists. Wear tests were performed in a dual-axis chewing simulator, and the volume loss in the antagonist tooth was evaluated using a laser scanner and three-dimensional profiling system. STATISTICAL ANALYSIS USED: Data were statistically analyzed using one-way analysis of variance with Tukey's post hoc tests (P < 0.05). Results: The maximum antagonist tooth wear was observed in group L (3.84 ± 0.7 mm3), followed by groups C (3.68 ± 0.76 mm3), R (3.48 ± 0.71 mm3), Z (2.66 ± 0.65 mm3), and E (1.66 ± 0.42 mm3). Volume loss was significantly lesser in group Z than in groups L and C (P < 0.05), whereas there were no significant differences among groups L, C, and R. CONCLUSION: Within the limitations of this in vitro study, our findings suggest that zirconia should be used for full coronal coverage in primary tooth restorations because it causes lesser antagonist tooth wear than does lithium disilicate, resin nanoceramic, and nanohybrid composite resin.

Comparative evaluation of biodentine, 2% chlorhexidine with RMGIC and calcium hydroxide as indirect pulp capping materials in primary molars: An in vivo study.

BACKGROUND: Indirect pulp therapy (IPT) is conventional treatment of deep dentinal carious lesions without risk of pulp exposure. Development of new biomaterials with biocompatibility and seal has changed the attitudes toward IPT. AIM/OBJECTIVES: This study was conducted to evaluate and compare the clinical and radiographic success of biodentine, 2% chlorhexidine gluconate with resin-modified glass ionomer cement (RMGIC), and calcium hydroxide as indirect pulp-capping materials in primary molars over an observation period of 12 months. MATERIALS AND METHODS: A total of 54 primary molars within the age group of 3-9 years, which were indicated for IPT were randomized into three groups of 18 samples each; Group I: biodentine, Group II: 2% chlorhexidine gluconate followed by RMGIC, Group III: calcium hydroxide (Dycal). These cases were followed up for evaluation clinically and radiographically at 3, 6, and 12 months. The recorded data were subjected to statistical analysis using Chi-square test. RESULTS: After 12 months, the clinical and radiographic success of biodentine group was 100% (18/18), with 2% chlorhexidine gluconate disinfecting solution followed by RMGIC was 94.4% (17/18) and calcium hydroxide (Dycal) was 94.4% (17/18), failures included one at 3 months with RMGIC and another at 12 months with calcium hydroxide group; but there was no statistically significant difference observed between them with P = 0.361 at 3 months and P = 0.371 at 12 months interval. CONCLUSION: Biodentine can be effectively used as indirect pulp-capping medicament in primary teeth which has similar clinical and radiographic success as 2% chlorhexidine gluconate in conjunction with RMGIC and calcium hydroxide.

The effect of Er,Cr:YSGG laser, fluoride, and CPP-ACP on caries resistance of primary enamel.

The aim of this in vitro study was to determine the effect of different remineralization agents and laser on caries resistance of primary enamel. In the study, 150 sound primary molars were used. The initial microhardness values were measured and the teeth were randomly assigned to ten treatment groups (n = 15): no treatment/negative control (C), NaF, APF, fluoride varnish (FV), CPP-ACP, laser (L), L + NaF, L + APF, L + FV, L + CPP-ACP. The microhardness values were measured after the treatments and the pH cycle. The obtained data were analyzed statistically. One sample from each group was examined before treatment, after treatment, and after the pH cycle with a scanning electron microscope. While microhardness values after treatment compared to baseline increased, microhardness after the pH cycle decreased compared to after treatment values in all experimental groups (p < 0.05). In regard to the difference in microhardness after the pH cycle and baseline, there were no statistically significant differences between groups C and NaF and between C and CPP-ACP (p > 0.05). There was a significant difference between groups L and L + FV (p < 0.05), while no significant difference was noted between groups L and L + NaF, L + APF, L + CPP-ACP (p > 0.05). As a conclusion, FV is more effective when used in combination with laser than laser alone. NaF, CPP-ACP, and laser may be insufficient in protecting the primary teeth against acid attacks compared to FV used with laser.

Dental pulp-derived stem cell conditioned medium to regenerate peripheral nerves in a novel animal model of dysphagia.

In nerve regeneration studies, various animal models are used to assess nerve regeneration. However, because of the difficulties in functional nerve assessment, a visceral nerve injury model is yet to be established. The superior laryngeal nerve (SLN) plays an essential role in swallowing. Although a treatment for SLN injury following trauma and surgery is desirable, no such treatment is reported in the literature. We recently reported that stem cells derived from human exfoliated deciduous teeth (SHED) have a therapeutic effect on various tissues via macrophage polarization. Here, we established a novel animal model of SLN injury. Our model was characterized as having weight loss and drinking behavior changes. In addition, the SLN lesion caused a delay in the onset of the swallowing reflex and gain of laryngeal residue in the pharynx. Systemic administration of SHED-conditioned media (SHED-CM) promoted functional recovery of the SLN and significantly promoted axonal regeneration by converting of macrophages to the anti-inflammatory M2 phenotype. In addition, SHED-CM enhanced new blood vessel formation at the injury site. Our data suggest that the administration of SHED-CM may provide therapeutic benefits for SLN injury.

Costs and benefits of Papacarie in pediatric dentistry: a randomized clinical trial.

Papacarie gel is an agent that eliminates the need for local anesthesia and reduces the need for using a drill. However, there is no information regarding the cost per procedure. Therefore we analyzed the cost, per procedure, of Papacarie gel compared to the traditional method (drilling), and performed a comparison between these methods of carious tissue removal. A randomized clinical trial was performed with 24 children with an average age of 5.9 years old. Of these children, 12 were boys and 12 were girls, which resulted in a total of 46 restorations. Patients were separated into: Papacarie group (caries removal with the chemical-mechanical method - Papacarie gel) and Drill group (caries removal with the traditional method - drilling). Values of the materials used in the procedures, heart rate (before, 5 minutes during, and after dental treatment), and the total consultation duration were recorded. A level of significance of 5% was adopted. Papacarie had a lower cost per procedure ($ 0.91) when compared to the traditional method ($ 1.58). Papacarie provided a cost reduction of 42% compared to the traditional method. Using local anesthesia ($ 2.17), the cost reduction increased to 58%. In the procedure using drill + Papacarie ($ 1.37), the cost reduction was 33%. Heart rate, consultation duration, and number of restorations were not statistically different. Papacarie shows an excellent cost benefit for minimally invasive removal of carious tissue and is a feasible alternative for public health care.

Cellular profile of primary molars with pulp necrosis after treatment with antibiotic paste.

The interradicular region of primary molars is permeated by many foramina, channels and accessories that connect the pulp cavity with the periapical tissues anatomically. Thus, pulp decomposition products or drugs used in endodontic treatment can trigger inflammatory reactions. The aim of this study was to evaluate the blood cell profile of the alveolar region after extraction of primary molars treated with CTZ paste. Forty-eight primary molars were selected with clinical and radiographic signs of extraction. The sample was divided into three groups with 16 teeth each: Group 1-healthy teeth; Group 2-untreated decayed teeth; and Group 3-teeth treated with CTZ paste. Immediately after the extraction, blood from the interface of the tooth socket was collected and smears were performed for further evaluation. The slides were stained by the Fast Panoptic® method and analysed by two previously trained examiners who counted the leucocytes in sets of 100 cells/slide, differentiating them into neutrophils, lymphocytes, monocytes, eosinophils and basophils. The data were analysed statistically by the MANOVA test. The blood samples from Group 2 differed significantly from Group 1 samples for all classes of leucocytes, except basophils, with higher average for lymphocytes (62.56), monocytes (7.81) and eosinophils (2.31). For Group 3, there was a relative difference (P < 0.05) to Group 2, of monocytes and eosinophils values. The blood cellularity interface in the tooth socket of primary teeth treated with CTZ paste is similar to those of healthy, exfoliated teeth and physiologically different from untreated decayed teeth.

Effects of a potentially erosive antiasthmatic medicine on the enamel and dentin of primary teeth: An in situ study.

This study evaluates, in situ, the effect of an anti-asthmatic medicine on the enamel and dentin of primary teeth. Twenty-eight specimens of enamel and dentin were prepared, selected, sterilized, and stored. Microhardness, microscopic morphology, and initial surface roughness were evaluated. Fourteen volunteers wore palatal devices containing two dentin specimens and two enamel specimens. Volunteers underwent surface treatment three times a day for 5 days, with the dripping of 5 ml of salbutamol sulfate for 1 min, only on specimens from one side of the device. At the end of the experiment the microscopic morphology, roughness, surface loss, and microhardness were ascertained. For enamel surfaces exposed to the medicine, erosion was observed in the microscopy images, along with a significant increase in roughness (p = .0325) and tissue loss (p = .03251) and a significant decrease in microhardness (p = .0325). For the dentin surfaces, erosion was observed in the microscopy images, but there was no significant increase in roughness (p = .593) or tissue loss (p = .285) nor any decrease in microhardness (p = .1088). In conclusion, the salbutamol sulfate had an in situ erosive effect on primary teeth enamel and this effect was observed morphologically on primary dentin. RESEARCH HIGHLIGHTS: Asthma is considered a global health problem, and its prevalence has increased in many countries, especially among children, as well as dental erosion. This study has clinical relevance because provides data on the erosive effect of a commonly prescribed anti asthmatic drug on deciduous teeth.

Effect of fluoridated varnish and silver diamine fluoride on enamel demineralization resistance in primary dentition.

BACKGROUND: International data on caries epidemiology confirm that dental caries remains a significant disease of childhood in both developing and developed countries. Based on preventive dentistry, topical fluoride may be a useful measure to arrest caries lesions. Fluoride used in various forms have been proven to be effective in dental caries prevention. AIM: This study aims to compare the effect of fluoridated varnish and silver diamine fluoride (SDF) solution on primary teeth enamel resistance to demineralization. METHODS: Forty-five caries-free deciduous canine teeth extracted due to orthodontic reasons, devoid of any defects were selected. Teeth were mounted on acrylic blocks as their buccal surface was exposed and baseline surface microhardness (SMH) determination was accomplished. Enamel samples were randomly distributed into three groups with 15 specimens each. One group was used as control (distilled and deionized water) (C); in the other groups, either a fluoridated varnish (V) or an SDF solution was applied to the enamel blocks. The blocks of each group were submitted to pH-cycling solutions and treatment regimen. After pH-cycling process, SMH determination was done again for all samples. RESULTS: According to the present findings, the percentage of decrease in SMH of control group is numerically greater than other groups and also SDF group shows the most resistance against mineral loss. However, based on one-way ANOVA test, this difference is not statistically significant (P = 0.217). CONCLUSION: SDF solution and fluoride varnish display similar effectiveness in preventing the demineralization of deciduous anterior teeth, and no significant difference was observed.

Surface remineralization potential of nano-hydroxyapatite, sodium monofluorophosphate, and amine fluoride containing dentifrices on primary and permanent enamel surfaces: An in vitro study.

BACKGROUND: Organic amine fluorides and nano-hydroxyapatite dentifrices have shown remineralization potential in various studies. However, there is a lack of direct comparison between amine fluoride and nano-hydroxyapatite with conventional inorganic fluorides as sodium monofluorophosphate. AIM: The aim of the study is to evaluate remineralizing efficacy of the three dentifrices on both primary and permanent enamel surfaces. METHODS: Enamel sections were obtained from 40 sound molars - 20 primary and 20 permanent molars. Five enamel slabs were prepared from these extracted molars stored in artificial saliva, wherein one slab acted as control, second as demineralized (negative control), and other three slabs were brushed with sodium monofluorophosphate, amine fluoride, and nano-hydroxyapatite dentifrices, respectively, twice daily for 21 days. Scanning electron microscopy- Energy dispersive spectroscopy (SEM-EDS) analysis for surface morphology and calcium and phosphorus content and Vickers surface microhardness (SMH) values were evaluated at baseline, after demineralization, and postapplication of the experimental agents. RESULTS: Highly significant changes in calcium phosphorus ratio and SMH values were seen in enamel slabs treated with nano-hydroxyapatite and amine fluoride dentifrice as compared to sodium monofluorophosphate in both primary and permanent teeth. Surface morphology of enamel slabs treated with amine fluoride most closely resembled natural enamel morphology, while sodium monofluorophosphate-treated surfaces showed globular pattern of remineralization. Deposition of a separate highly mineralized layer over existing surface was seen in nano-hydroxyapatite-treated surfaces. CONCLUSIONS: Nano-hydroxyapatite exhibited highest remineralization potential in terms of mineral gain followed by amine fluoride and sodium monofluorophosphate dentifrice.

Antimicrobial Photodynamic Therapy as an Adjunct for Clinical Partial Removal of Deciduous Carious Tissue: A Minimally Invasive Approach.

This study aimed to evaluate the use of antimicrobial photodynamic therapy (aPDT) as an adjunct for minimally invasive treatment (partial removal of carious tissue-PRCT) of deciduous carious tissue evaluating its efficacy in reducing microorganisms. For that, a clinical study was design including children with deciduous molars with active deep caries lesions (DCL). PRCT was performed and remaining dentin was treated with 100 µg mL-1 methylene blue solution (5 min) and than irradiated with a low power laser emitting red light (InGaAIP-indium gallium aluminum phosphide; λ = 660 nm; 100 mW; 300 J cm-2 ; 90 s; 9 J). The colony forming units (CFU) count after PRCT and after PRCT + aPDT/mg of dentin were compared for total microorganisms, including Candida spp., the mutans streptococci group, Streptococcus spp. and Lactobacillus spp. The dentin was classified (color, consistency and humidity). The microbial reduction varied from 69.88% to 86.29% and was significantly observed for total microorganisms, mutans streptococci, Streptococcus spp. and Lactobacillus spp (P < 0.001). The dentin type did not influence reduction of microorganisms (P > 0.05). The aPDT presents a promising future for clinical use as an adjunct for the reduction of microorganisms in PRCT of DCL in all kinds of dentin.

Can Chlorhexidine enhance the Bond Strength of Self-etch and Etch-and-rinse Systems to Primary Teeth Dentin?

Introduction: Modifying the durability of resin bonding systems resulted in introducing materials with cross-link property, such as chlorhexidine (CHX) that can promote the strength of resin-dentin bonding. The aim of this study was evaluation of the effect of CHX on shear bond strength (SBS) of self-etch (SE) and etch-and-rinse (E&R) bonding systems to the primary teeth dentin. Materials and methods: In this in vitro study, 40 freshly extracted primary molars collected and were cut mesiodistally, and then the buccal and lingual surface enamel was grounded. The specimens were randomly divided into two groups: I: Single Bond adhesive and II: Clearfil SE Bond adhesive. Then, each group was divided into two subgroups: On the buccal surface of each sample CHX was applied for 30 seconds and on the lingual surface of (I2, II2 groups), CHX was not applied. The SBS (MPa) of samples was assessed using the Zwick universal testing machine. Data were analyzed by paired t-test and independent t-test using Statistical Package for the Social Sciences (SPSS), version 16. Results: The mean SBS was significantly higher in the Single Bond group with CHX (66.45 ± 8.3) than without CHX (25.43 ± 12.94) in the nonaging group (p = 0.002). There was no significant difference in the mean SBS in the Clearfil SE Bond group with CHX and without CHX in the aging and nonaging groups. Conclusion: CHX had positive influence on immediate SBS of Single Bond adhesive to primary teeth dentin. In addition, no positive effect has been seen in the Clearfil SE Bond system. Clinical significance: Now more researches are needed about the recommendation of CHX in resin restorations of primary teeth. Keywords: Chlorhexidine, Etch-and-rinse adhesive, Failure pattern, Self-etch adhesive, Shear bond strength.