[Evaluation of dental treatment impact in a northwestern Mexican school children population]. / Evaluación del impacto del tratamiento odontológico en una población escolar del noroeste de México.

OBJECTIVE: To evaluate through functional teeth index, the impact in schoolchildren in communities with and without dental community support. MATERIAL AND METHODS: A cross-sectional study was carried out in communities with dental care provided by dental clinics of Sinaloa State University. The study sample was 2,083 schoolchildren. We used the criteria proposed by WHO for the index of decayed, missing-teeth (DMFT) for permanent dentition, index for prima- ry teeth (dmft) and the rate of functional teeth (RFT). For bivariate analysis, the nonparametric tests Pearson f and Mann-Whitney U were used. RESULTS: The comparisons of DMFT (0.20) and RFT (13.95) of children with and DMFT (0.43) and RFT (14.82) of children without community dental support showed statistical significant difference (p < 0.05). There was a statistically significant difference in DMFT and RFT between samples with and without community dental support (p < 0.05). The age showed a statistically significant difference between the DMFT and dmft (p < 0.05). Primary dentition required more dental care than permanent dentition. There was access for dental treatment, but it is not used for the population. CONCLUSIONS: The RFT provided precise information than DMFT, mainly due to register the changes of actions focused to recover the teeth function in the oral cavity.

[Predicting risk of caries in schoolchildren from northwestern Mexico: longitudinal study]. / Predicción de riesgo de caries en escolares del noroeste de México: estudio longitudinal.

OBJECTIVE: To analyze the caries risk through the Bratthall's Cariogram (BC) and the frequency of dental caries in a Mexican northwest children population for 12 months period. MATERIAL AND METHODS: A cohort of 583 scholar children between 6 and 10 years old from Sinaloa state was involved for 12 months period (2007-2008). The Bratthall's Cariogram was used to predict caries risk and the. WHO's criteria were used to obtain the caries index. The caries risk association with clinical variables was analyzed by logistic regression analysis and Sperman's Rho rank correlation test was used to evaluate the correlation between DMFT index and BC. RESULTS: The caries risk increased with respect to age (p < 0.05), the CB identified correctly children for high risk (85%) and low risk (65%) caries for a 12 months period. The baseline values of BC showed a positive correlation with DMFT index (0.86 and p = 0.0001); the diagnostic test evaluation showed the following values: positive predictive value of 87%, negative predictive value of 63%, sensitivity of 93% and specificity of 63%. CONCLUSIONS: The caries risk increased with the age in the studied population. The Bratthall's Cariogram is a useful screening test to evaluate the risk for dental caries at individual and population levels.

Comparative study of dental enamel loss after debonding braces by analytical scanning electron microscopy (SEM).

Clinical procedures when shear forces are applied to brackets suggest adhesion forces between 2.8 and 10.0 MPa as appropriate. In this study dental enamel was evaluated by scanning electron microscopy (SEM) before and after removing the brackets. Thirty bicuspids (previous prophylaxis) with metallic brackets (Roth Inovation 0.022 GAC), Transbond Plus SEP 3M Unitek adhesive and Transbond XT 3M resin were used. The samples were preserved to 37°C during 24 hr and submited to tangential forces with the Instron Universal machine 1.0 mm/min speed load strength resistance debonding. Also the Adhesive Remanent Index (ARI) test was made, evaluating the bracket base and the bicuspid surface. All the bracket SEM images were processed with AutoCAD to determine the enamel detached area. The average value was 6.86 MPa (SD ± 3.2 MPa). ARI value 1= 63.3%, value 2= 20%, value 3= 13.3% and 33% presented value 0. All those samples with dental enamel loss, presented different situations as fractures, ledges, horizontal, and vertical loss in some cases, and some scratch lines. There is no association between the debonding resistance and enamel presence. Less than half of the remanent adhesive on the dental enamel was present in most of the samples when the ARI test was applied. When the resin area increases, the debonding resistance also increases, and when the enamel loss increases, the resin free metallic area of the bracket base decreases in the debonding.

Phase composition of ProRoot mineral trioxide aggregate by X-ray powder diffraction.

INTRODUCTION: Composition and crystalline phases of the endodontic material mineral trioxide aggregate (MTA) is of fundamental importance for understanding its physical and chemical properties. This research was done to determine the composition of crystalline phases for ProRoot MTA. METHODS: For phase identification, powder of ProRoot MTA was analyzed by x-ray diffraction (XRD), comparing the MTA peaks with the data contained in the Powder Diffraction File of the International Centre for Diffraction Data (ICDD). To help the task of identifying a phase, chemical analysis by energy-dispersive spectrometry (EDS) and particle-induced x-ray emission (PIXE) were applied. Quantitative phase analysis was performed by applying Rietveld refinement to the XRD data. RESULTS: ProRoot MTA is composed of bismuth oxide (19.8%), tricalcium silicate (51.9%), dicalcium silicate (23.2%), calcium dialuminate (3.8%), and calcium sulfate dehydrated (1.3%). The trace elements detected were Fe, Ni, Cu, and Sr. CONCLUSIONS: Rietveld refinement was able to analyze the composition of ProRoot MTA, which is based basically on a mixture of Portland cement (with smaller quantities of calcium dialuminate and calcium sulfate dehydrated) and bismuth oxide for radiopacity.