Fernando Borba de Araujo

Dentin-derived BMP-2 and Odontoblast Differentiation

It is known that stem cells from exfoliated deciduous teeth (SHED) can be induced to differentiate into odontoblasts. However, the nature of dentin-derived morphogenic signals required for dental pulp stem cell differentiation remains unclear. The hypothesis underlying this work is that dentin-derived Bone Morphogenetic Proteins (BMP) are necessary for the differentiation of SHED into odontoblasts. We observed that SHED express markers of odontoblastic differentiation (DSPP, DMP-1, MEPE) when seeded in human tooth slice/scaffolds and cultured in vitro, or implanted subcutaneously into immunodeficient mice. In contrast, SHED cultured in deproteinized tooth slice/scaffolds, or scaffolds without a tooth slice, do not express these markers. SHED express the BMP receptors BMPR-IA, BMPR-IB, and BMPR-II. Notably, blockade of BMP-2 signaling inhibited the expression of markers of odontoblastic differentiation by SHED cultured in tooth slice/scaffolds. Collectively, this work demonstrates that dentin-derived BMP-2 is required to induce the differentiation of SHED into odontoblasts.

Endothelial Differentiation of SHED Requires MEK1/ERK Signaling

The discovery that dental pulp stem cells are capable of differentiating into endothelial cells raises the exciting possibility that these cells can be a single source of odontoblasts and vascular networks in dental tissue engineering. The purpose of this study was to begin to define signaling pathways that regulate endothelial differentiation of SHED. Stem cells from exfoliated deciduous teeth (SHED) exposed to endothelial growth medium (EGM-2MV) supplemented with vascular endothelial growth factor (VEGF) differentiated into VEGFR2-positive and CD31-positive endothelial cells in vitro. In vivo, VEGFR1-silenced SHED seeded in tooth slice/ scaffolds and transplanted into immunodeficient mice showed a reduction in human CD31-positive blood vessels as compared with controls (p = 0.02). Exposure of SHED to EGM2-MV supplemented with VEGF induced potent activation of ERK and Akt signaling, while it inhibited phosphorylation of STAT3. Notably, genetic (MEK1 silencing) or chemical (U0126) inhibition of ERK signaling restored constitutive STAT3 phosphorylation and inhibited the differentiation of SHED into endothelial cells. Collectively, analysis of these data unveiled the VEGF/MEK1/ERK signaling pathway as a key regulator of the endothelial differentiation of dental pulp stem cells.

Hydrops fetalis associated with erythrocyte pyruvate kinase deficiency

Abstract The authors report a case of hydrops fetalis due to severe pyruvate kinase deficiency, the most unusual clinical manifestation of this disease. Conclusion Pyruvate kinase deficiency, as other erythrocyte enzymopathies, must be considered in the differential diagnosis of non-immune hydrops fetalis. This has important implications for clinical investigations, therapy and genetic counselling.

Outcomes of one-step incomplete and complete excavation in primary teeth: a 24-month randomized controlled trial.

Aim: To compare 24-month pulp health outcomes of partial caries removal (PCR) and total caries removal (TCR) with composite restoration in primary molars. Methods: 48 children aged 3-8 years with at least one molar with a deep carious lesion were included. 120 teeth were randomized to control (TCR; n = 54; 69% class II) and test (PCR; n = 66; 63% class II) groups. Total absence of carious tissue was confirmed using a blunt-tipped probe in the TCR group. For PCR, excavation was stopped when hardened, dried dentin with a leathery consistency was achieved. Pulpotomy was performed in cases of pulp exposure. Results: Pulp exposure occurred in 2 and 27.5% of teeth treated with PCR and TCR, respectively (p < 0.01). The operative time was significantly higher for TCR than PCR. Success rates were 92 and 96% in the PCR and TCR groups, respectively (p = 0.34). The success rate tended to be lower in occlusoproximal (92%) than in occlusal (100%) lesions (p = 0.08). Conclusion: The clinical and radiographic success rates of PCR and TCR in primary teeth with deep carious lesions were high and did not differ significantly, indicating that PCR is a reliable minimally invasive approach in primary teeth and that the retention of carious dentin does not interfere with pulp vitality. Moreover, PCR provided other clinically relevant advantages over TCR, especially lower incidence of pulp exposure and lower operative time.

Vertical alveolar growth in subjects with infraoccluded mandibular deciduous molars

INTRODUCTION Our objective was to compare vertical alveolar growth in areas adjacent to infraoccluded deciduous molars with growth in areas of deciduous molars and normal occlusion for a period of at least 1 year by using digital subtraction radiography. METHODS This case-control study included 40 pairs of panoramic radiographs of growing patients with infraoccluded deciduous molars and 40 pairs of radiographs of patients without infraoccluded deciduous molars. One radiograph at baseline was obtained at diagnosis, and the other at least 1 year later. The subjects and the controls were matched according to chronologic age and time interval between the 2 radiographs. The 2 groups were compared with regard to vertical alveolar growth and vertical tooth movement. Measurements were assessed by using nonparametric tests (Mann-Whitney and Friedman) and a multiple comparison test. Significance was set at 5%. RESULTS A statistically significant difference was observed between the groups with regard to vertical alveolar growth measured on the bone crest between the first permanent molars and second premolars. CONCLUSIONS Vertical alveolar growth between the first permanent molar and the second premolar adjacent to the infraoccluded teeth was smaller than in areas adjacent to teeth with normal occlusion.

Randomized controlled clinical trial of the 24-months survival of composite resin restorations after one-step incomplete and complete excavation on primary teeth

OBJECTIVE This randomized clinical trial aimed to compare the 24-months survival of composite restorations in primary molars after partial caries removal (PCR) and total caries removal (TCR). METHODS Forty-eight children aged 3-8 years with at least one molar with a deep carious lesion were included (PCR; n=66; TCR; n=54). For PCR, excavation was stopped when dentine with a leathery consistency was achieved; in the TCR group, total absence of carious tissue was confirmed using a blunt-tipped probe. Pulpotomy was performed in cases of pulp exposure. Success was assessed by modified USPHS criteria with Alpha and Bravo scores recorded as success. RESULTS Pulp exposure occurred in 1 and 15 of the teeth treated with PCR and TCR respectively (p<0.01). The restorations survival rate after 24 months was 66% (PCR) and 86% (TCR) (p=0.03). When teeth that received pulpotomy were analyzed separately, the survival rate was 92% (p=0.09). PCR performed in occlusoproximal restorations demonstrated the lowest success rate (p=0.002). PCR increases 2.90 times the probability of having a restorative failure compared to TCR (p=0.03), after adjusting for cavity type. When pulp exposure and restoration failure were considered as the outcome, there was no significant difference between the two groups (p=0.10) with success rates of 64% (PCR) and 61% (TCR). CONCLUSION Collectively, deciduous teeth submitted to PCR prevented pulp exposure and, consequently, more invasive treatments; otherwise, PCR yielded lower longevity for composite restoration compared to TCR, suggesting that PCR restorations need to be followed over time, especially when multi-surface restorations are involved. CLINICAL SIGNIFICANCE Composite restorations on carious remaining tissue require monitoring over time, especially those performed in more than one surface. Even if the restorations present shortcomings over the time, the majority of them are subject to repair, allowing more conservative approaches for teeth with deep caries lesions.

Professional flossing as a diagnostic method for gingivitis in the primary dentition

The aim of this study was to evaluate flossing as a diagnostic method for interproximal gingival bleeding in children. For this crossover study, 23 pre-schoolchildren presenting neither restorations nor approximal carious cavities and with at least 15% of gingival bleeding sites were selected. Examinations were performed at three different moments (3-4 days interval). Examinations comprised repeated measurements of two gingival indices with a 10-minute interval in the following sequences: the Ainamo & Bay Gingival Bleeding Index (GBI) followed by the Carter & Barnes flossing index (CBI); CBI followed by GBI; and GBI followed by GBI. Data analysis was performed only for the interproximal sites, considering the GBI as the gold-standard. Agreement between indices, sensitivity (SE), specificity (SP), positive (PPV) and negative predictive values (NPV) were estimated. Percentage agreements in sequences GBI-CBI, CBI-GBI and GBI-GBI were 70.3%, 76.4% and 84.5%, respectively. Validation of flossing in the first sequence (GBI-CBI) resulted in values of 0.61 (95%CI 0.53 - 0.68), 0.72 (95%CI 0.69 - 0.76), 0.33 (95%CI 0.28 - 0.39) and 0.89 (95%CI 0.86 - 0.92) respectively for SE, SP, PPV and NPV. It can be concluded that professional flossing is a useful tool in the diagnosis of interproximal gingival inflammatory status in children, especially in conditions of gingival health.

Differential Impacts of Caries Classification in Children and Adults: A Comparison of ICDAS and DMF-T.

The aim of this study was to describe and compare findings regarding the prevalence and severity of dental caries when using ICDAS and DMFT/dmft in an epidemiological study with children and their mothers. This cross-sectional study evaluated 150 preschoolers and their mothers. Data were collected with ICDAS and then transformed into DMFT/dmft. ICDAS scores related to caries were analyzed according to three different cut-off-points: CP1 (0-healthy/1-6-caries), CP2 (0-1-healthy/2-6-caries) and CP3 (0-2-healthy/3-6-caries), representing the D/d of DMFT/dmft. ICDAS codes regarding restorations, except sealants, were considered the F/f and the code 97 as the M/m of DMFT/dmft index. Prevalence of caries and its severity with ICDAS were 92%, 84% and 31.3% in children and 97.3%, 96.6% and 80% in adults according to CP1/CP2/CP3, respectively. Admitting CP3 as the standard for data transformation of ICDAS in DMFT/dmft, it was observed that DMFT/dmft index would underestimate 60% of non-cavitated lesions in children and 16.6% in adults. The DMFT/dmft underestimated the presence of disease to disregard non-cavitated lesions for the pediatric population evaluated. The choice of which is the best index for epidemiological surveys will depend on the purpose of the research and the target population: if it is to estimate the needs of the population to determine clinical care in children and adults, the DMFT/dmft may be sufficient. However, if the objective is to have a more comprehensive diagnosis of caries at the population level in order to develop preventive strategies, to halt and reverse the disease, the detection of non-cavitated-lesions becomes important, mainly in young children.

Survival and Associated Risk Factors of Selective Caries Removal Treatments in Primary Teeth: A Retrospective Study in a High Caries Risk Population

Objective: The aim of this retrospective study was to analyze the survival probability of selective caries removal (SCR) treatments in the primary teeth of children with high caries experience and factors potentially associated with treatment failure. Methods: The sample included SCR treatments conducted in anterior and posterior teeth without sedation or general anesthesia among children attending a university dental service. Kaplan-Meier survival analysis was used to estimate the longevity of restorations and multivariate Cox regression with shared frailty was used to assess risk factors. Results: A total of 284 SCR treatments in 88 children (aged 5.2 ± 1.91 years) with high caries experience (mean dmft/DMFT = 11.1 ± 5.04) were analyzed. The 3-year survival reached 48.8%, with an annual failure rate of 21.2%. Restorative failures (n = 60) were found more frequently compared to pulp complications (n = 12). SCR performed in anterior primary teeth were more prone to failure (hazard ratio = 3.6, 95% CI: 1.94; 6.71). Patients with a higher amount of visible plaque experienced more failures in SCR treatments (hazard ratio 3.0, 95% CI:1.27; 7.07). Conclusions: In this retrospective study, SCR showed restricted survival when compared to other prospective clinical trials. Patient-related factors, especially the young age and high caries experience of the children, may represent a challenge for restoration survival. Regardless of the caries removal technique or restorative material, cariogenic biofilm has a negative effect on the survival of restorations, probably by acting directly on material deterioration and, particularly, on the development of new caries lesions of rapid progression.

A Longitudinal Study of Early Childhood Caries and Associated Factors in Brazilian Children

Early childhood caries (ECC) affects children all over the world and has high prevalence and severity in preschool children. Different social, biological and behavioral factors compose a network of causal factors for ECC. The aim was to evaluate the association between socioeconomic variables and caries at baseline, and the presence of Streptococcus mutans and Lactobacillus spp. microorganisms with the progression of caries lesions after two years of follow-up in a group of children. At baseline, 163 children (3-4 years old) living in the areas of 12 primary care services of the Hospital Group Conceição (GHC, Porto Alegre, RS, Brazil) were evaluated. After two years, 119 children were re-evaluated. Clinical examinations were conducted by calibrated examiners using the ICDAS criteria. A sociodemographic questionnaire was applied to the childrens parents and saliva samples were collected from the children for microbiological analysis. Descriptive statistics and multivariate Poisson regression analysis were performed in the statistical analysis. The factors associated with the caries progression were marital status of mothers (p=0.040), higher S. mutans counts (p=0.031) and the presence of cavitated lesions at baseline (p<0.001). The caries lesions progression in preschool children enrolled in primary health care was directly associated with marital status, presence of cavitated lesions at baseline and higher S. mutans counts at two-year follow-up.