Fundamentals in Biostatistics for Research in Pediatric Dentistry: Part I - Basic Concepts.

The purpose of this report was to provide the reader with some basic concepts in order to better understand the significance and reliability of the results of any article on Pediatric Dentistry. Currently, Pediatric Dentists need the best evidence available in the literature on which to base their diagnoses and treatment decisions for the children's oral care. Basic understanding of Biostatistics plays an important role during the entire Evidence-Based Dentistry (EBD) process. This report describes Biostatistics fundamentals in order to introduce the basic concepts used in statistics, such as summary measures, estimation, hypothesis testing, effect size, level of significance, p value, confidence intervals, etc., which are available to Pediatric Dentists interested in reading or designing original clinical or epidemiological studies.

Multiwall carbon nanotubes/polycaprolactone scaffolds seeded with human dental pulp stem cells for bone tissue regeneration.

Conventional approaches to bone regeneration rarely use multiwall carbon nanotubes (MWCNTs) but instead use polymeric matrices filled with hydroxyapatite, calcium phosphates and bioactive glasses. In this study, we prepared composites of MWCNTs/polycaprolactone (PCL) for bone regeneration as follows: (a) MWCNTs randomly dispersed on PCL, (b) MWCNTs aligned with an electrical field to determine if the orientation favors the growing of human dental pulp stem cells (HDPSCs), and (c) MWCNTs modified with ß-glycerol phosphate (BGP) to analyze its osteogenic potential. Raman spectroscopy confirmed the presence of MWCNTs and BGP on PCL, whereas the increase in crystallinity by the addition of MWCNTs to PCL was confirmed by X-ray diffraction and differential scanning calorimetry. A higher elastic modulus (608 ± 4.3 MPa), maximum stress (42 ± 6.1 MPa) and electrical conductivity (1.67 × 10(-7) S/m) were observed in non-aligned MWCNTs compared with the pristine PCL. Cell viability at 14 days was similar in all samples according to the live/dead assay, but the 21 day cell proliferation, measured by MTT was higher in MWCNTs aligned with BGP. Von Kossa and Alizarin red showed larger amounts of mineral deposits on MWCNTs aligned with BGP, indicating that at 21 days, this scaffold promotes osteogenic differentiation of HDPSCs.

Probiotics and their effect on oral bacteria count in children: a pilot study.

AIM: To assess the effect of the daily ingestion of a mixture of probiotics on the amount of Streptococcus mutans in the oral cavity of preschool-age patients with a high risk of caries. MATERIALS AND METHODS: Forty patients, aged between 4 and 6 years, with a high risk of dental caries were included in this pilot study. Patients were randomly assigned to two study groups: the Experimental Group (A) included patients who brushed their teeth and used fluoridated toothpaste in addition to consuming probiotics daily, and the Control Group (B) inclused patients who brushed their teeth and used fluoridated toothpaste but did not consume probiotics. Using the CariScreen, the microorganism count was determined at different times: baseline, 7, 14, 21 and 30 days. To identify the differences between both groups, a Mann-Whitney U test was performed, with a significance level of 0.05. RESULTS: It was observed that both groups showed similar microbial counts at the beginning of the trial (p>0.05), and a significant decrease in the count at the end of the study was found in the experimental group (p<0.05) 15 days after suspending ingestion. CONCLUSION: We found a significant reduction of RLU values in preschool children who ingested the tested probiotics in relation to the baseline values and 15 days after ceasing consumption.

Colonization levels of Streptococcus mutans between mother and infant: a postnatal prospective cohort study.

OBJECTIVE: To investigate the possible association between maternal S. mutans levels and those of the infant during the period between birth and 5 months and evaluate possible risk factors in the S mutans colonization. STUDY DESIGN: A prospective cohort study was carried out comprising 62 infants and their mothers, selected at the time of childbirth. For each infant, a sample swab was taken at 0, 15, 30, 90, and 150 days postpartum; on the same days, a sample was obtained from the mothers. TYCSB medium was employed for identifying the microorganism, which was later confirmed by Gram staining, the catalase activity test, and the API strep test. RESULTS: The final total sample consisted of 60 infants, from which S. mutans was detected in only 2 (3%) at the 150th day of oral sample collection. Of the sample of 60 mothers, 54 exhibited colonization levels. CONCLUSIONS: In the studied sample pairs up to 150 days, it was not possible to demonstrate the presence of a direct relationship between maternal S. mutans oral levels.

Comparison of the antibacterial effect of modified 3-mix paste versus Ultrapex over anaerobic microorganisms from infected root canals of primary teeth: an in vitro study.

OBJECTIVE: The aim of this study was to evaluate in vitro the antimicrobial efficacy of a modified 3-mix paste and to compare it with an iodoform paste (Ultrapex) against anaerobic microorganisms isolated from root canals of infected or necrotic primary teeth. STUDY DESIGN: An in vitro experimental assay was performed over isolated and identified anaerobic microorganisms of 21 samples, in order to compare the antimicrobial ability of both root canal filling materials, using a disc-diffusion method. RESULTS: A total of 21 microbial samples (15 polymicrobial and 6 monomicrobial) were obtained, from which 19 different strains were identified. Modified 3-mix paste showed an excellent antimicrobial effect against most of both kinds of microbial samples, although some of them exhibited resistance; on the other hand, Ultrapex showed only minimal antimicrobial ability (null or low categories). Clostridium ramosum exhibited the most resistance to both materials. CONCLUSION: The bactericidal effect of the modified 3-mix paste was superior to Ultrapex, with a statistically significant difference, against anaerobic microorganisms isolated from infected root canals of primary teeth.

Effectiveness of oxidative potential water as an irrigant in pulpectomized primary teeth.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of oxidative potential water (OPW) as an irrigating solution in reducing bacterial loading in necrotic pulpectomized primary teeth. STUDY DESIGN: Forty necrotic teeth were included, 20 irrigated with OPW (experimental group) and 20 with 1% NaOCl (control group); in both groups, 2 microbiological samples from within the canals were taken with a sterile paper point, the first before irrigation (immediately before opening the crown), and the second after instrumentation and final irrigation (before filling). All samples were evaluated by McFarland's scale. RESULTS: After the samples were analyzed before and after irrigation in the control group, there was a significant decrease in bacterial load, as in the experimental group (P < 0.0001). When both groups were compared post irrigation, no significant difference was observed (P = 0.1519). CONCLUSION: The OPW was as effective as the NaOCl and is suggested as an alternative for irrigating after pulpectomy of necrotic primary teeth.

Idiopathic ulcers as an oral manifestation in pediatric patients with AIDS: multidisciplinary management.

HIV infection is a major global health problem affecting developing and developed countries alike. HIV infection is associated with multiple oral lesions, some of which are of value in diagnosing the disease. The aim of this report is to describe the clinical manifestations and their multidisciplinary management, in a 6-year-old girl with AIDS. The findings of this case report indicate that, it is essential to be familiar with the early oral manifestations of AIDS in order to understand the patient's dental health needs, apply preventive methods, control caries, and understand the value of oral lesions as diagnostic markers of disease progression in children with HIV infection. A multidisciplinary management is fundamental.

Reduction in bacterial loading using 2% chlorhexidine gluconate as an irrigant in pulpectomized primary teeth: a preliminary report.

OBJECTIVE: The aim of this study was to evaluate the reduction in bacterial loading using 2% chlorhexidine gluconate as an irrigating solution in pulpectomized primary teeth. STUDY DESIGN: A randomized, controlled clinical trial was performed that included primary teeth with pulp necrosis. Forty necrotic teeth were included, 20 irrigated with 2% chlorhexidine gluconate (experimental group) and 20 with sterile saline solution (control group); in all cases, 2 microbiological samples from within the canals were taken with sterile paper points, the first after the canal opening and before the first irrigation, and the second after instrumentation and final irrigation, before filling. All samples were evaluated by McFarlands scale. RESULTS: The results were statistically analyzed by the Mann-Whitney U test. After analyzing samples before and after irrigation in the control group (saline), we found a significant decrease of bacterial load (P < 0.0002). The same occurred in the chlorhexidine group samples (P < 0.0001). When both groups were compared post-irrigation, a statistically significant difference was observed in favor of 2% chlorhexidine gluconate. CONCLUSION: Two percent chlorhexidine gluconate showed a greater reduction of intracanal bacterial loading compared with that observed with sterile saline solution. This irrigating solution is suggested as an alternative for pulpectomy of necrotic primary teeth.

[Fluorosis in primary dentition in a region with endemic water fluoride]. / Fluorosis en dentición temporal en un área con hidrofluorosis endémica.

OBJECTIVE: The aim of the present study was to estimate the prevalence of dental fluorosis in primary dentition of a San Luis Potosi children population, and its association to fluoride concentration in drinking water and urine. An additional objective was, to develop, validate, and test a specific index for dental fluorosis in primary dentition. MATERIAL AND METHODS: From May 1997, to January 1999, we conducted a cross-sectional study to assess the prevalence of dental fluorosis in primary dentition. Study subjects were 100 children aged 3-6 years, selected at random from three kindergartens in three risk areas of San Luis Potosi. The specific index of dental fluorosis for primary dentition (Dental Fluorosis for Primary Dentition Index--DFPDI) was validated by estimating fluoride concentrations in enamel of teeth with and without dental fluorosis. The Kruskal-Wallis test was used to assess the association between fluoride concentrations in drinking water and urine, with dental fluorosis; the association between risk area and dental fluorosis was assessed with the Mantel-Haenszel chi 2 test. RESULTS: The prevalence of dental fluorosis in primary dentition was 78%; primary molars were most affected in both maxillae and the predominant color was a non-glossy white appearance. We found a strong direct correlation (r = 0.93) between fluoride concentrations in primary teeth and the DFPDI. Associations were found between fluoride concentrations of drinking water and urine, with dental fluorosis (Kruskal-Wallis p = 0.00001), and between risk area and dental fluorosis (Mantel-Haenszel chi 2 p = 0.00001). CONCLUSIONS: DFPDI allowed adequate identification and grading of dental fluorosis in primary dentition. It is important to detect the initial toxic effects of fluoride exposure to predict dental fluorosis in permanent dentition and skeletal fluorosis.

[Bottled beverages as additional sources of exposure to fluoride]. / Bebidas embotelladas como fuentes adicionales de exposición a flúor.

OBJECTIVE: To evaluate and to report the concentration of floride in soft drinks and juices consumed in San Luis Potosi, S.L.P., Mexico, and its implications as a risk factor for developing dental fluorosis. MATERIAL AND METHODS: The contents of some products from 2 main national companies and 2 other local companies were studied. The samples were collected from 10 different batches in the case of the soft drinks, and from 5 batches in the case of the juices, with 3 samples per batch, during 3 months. The ion selective electrode method was used to determine the concentration of fluoride. RESULTS: Soft drinks from 2 main national companies showed high fluoride concentrations that were statistically significant between groups (p < 0.05). Fluoride levels of products from local and national companies also showed differences that were statistically significant between groups (p < 0.05). All natural juices tested showed high fluoride concentrations. CONCLUSIONS: Most soft drinks and juices consumed in SLP had high fluoride levels above Mexican regulations (0.7 ppm) and could be a substantial risk factor for developing dental fluorosis.