The orthodontic miniscrew (TADs) is a device that is fixed into bone in the short term for the purpose of enhancing orthodontic anchorage. The aim of our study was to investigate the structural and surface properties of recovered TADs after orthodontic treatment, and compare them to new TADs. TADs (n = 15) from the same manufacturer (Absoanchor; Dentos, Daegu, Korea) were assessed; n = 10 were recovered from patients after orthodontic treatment and n = 5 were new. We performed electrochemical investigations, scanning electron microscopy (SEM) and microbiological analysis. Qualitative analysis on general electrochemical polarization revealed that the TADs retrieved from the patients provided much lower current densities in the passivity zone, and the oxidative processes taking place on their surface were of lower intensity. The surface morphologies of the tips of the retrieved mini-implants showed less sharp tips and smooth surfaces. Defects in the form of pores or cracks could be identified in both evaluated TAD groups. All retrieved TADs showed signs of biological materials (SEM analysis) and contamination on their surfaces. In conclusion, these results can assist orthodontists in comprehending the complexities of TAD behavior with respect to their design and structure.

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The aim of this study was to evaluate the correlations between the pH values of oral fluid and the epidemiologic indicators of dental caries in children aged between 6-12 years. Clinical examinations were performed on 1517 children and the analysis was made in groups of 6-8 years old (n=701) [male (n=353), female (n=348)], and 9-12 years old (n=786) [male (n=426), female (n=360)]. The research included the record the pH values of the oral fluid and clinical examinations for evaluation of the state of oral health, in conformity to the codes of the OMS carious affection level. For the determination and the record of pH values of the oral fluid we used GC Saliva pH Indicator kit. The study followed defs, deft, dmfs, dmft epidemiologic indices of dental caries. The determined values of oral fluid pH were between 5.0 and 6.4. The obtained values of indices in all studied groups and subgroups demonstrated the significant statistical difference between at least two values (p [ 0.001). 72% of the studied group presented with at least a dental surface affected in deciduous teeth, while only 40% of the children presented a carious process on the permanent teeth. The occlusal surface was the most frequently affected by dental caries, followed by the proximal surfaces (mesial and distal) and last being smooth surface caries. The study demonstrated the correlation between acidic values of oral fluid pH and the dental caries in the study group.

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