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Abstract. In this manuscript we consider the well-established problem of TDOA-based source localization and propose a comprehensive analysis of its solutions for arbitrary sensor measurements and placements. More specifically, we define the TDOA map from the physical space of source locations to the space of range measurements (TDOAs), in the specific case of three receivers in 2D space. We then study the identifiability of the model, giving a complete analytical characterization of the image of this map and its invertibility. This analysis has been conducted in a completely mathematical fashion, using many different tools which make it valid for every sensor configuration. These results are the first step towards the solution of more general problems involving, for example, a larger number of sensors, uncertainty in their placement, or lack of synchronization.

The objective of this study is to compare the effects of canine guidance (CG) and bilateral balanced occlusion (BBO) on denture satisfaction and kinesiographic parameters of complete denture wearers, by means of a cross-over trial. Fifty edentulous patients received new maxillary and mandibular complete dentures. After the intra-oral adjustments and adaptation period, 44 participants were enrolled in the trial and randomly received a sequence of occlusal schemes: BBO followed by CG, or CG followed by BBO. Outcomes were assessed after 30 days of each occlusal scheme. Participants answered a denture satisfaction questionnaire and a kinesiograph instrument recorded mandibular physiologic movements and pattern of maxillary denture movement during chewing. Wilcoxon test and paired sample t-test were used to compare satisfaction levels and kinesiographic data for each occlusal scheme, respectively (α=0.05). The results showed no differences between occlusal schemes on participant's satisfaction and in any of the kinesiographic parameters studied, except for the vertical intrusion of the maxillary complete denture during chewing, which was lower with CG. It can be concluded that the occlusal scheme did not influence on satisfaction and kinesiographic parameters evaluated, as long as volume and resilience of residual edentulous ridges of the participants were normal. Clinical Trial Registration Identifier: NC.T01420536.

Despite the large number of studies addressing the effect of microwave polymerization on the properties of acrylic resin, this method has received limited clinical acceptance. This study evaluated the influence of microwave polymerization on the flexural strength of a denture base resin. A conventional heat-polymerized (Clássico), a microwave-polymerized (Onda-Cryl) and a autopolymerizing acrylic (Jet) resins were used. Five groups were established, according to polymerization cycles: A, B and C (Onda-Cryl, short cycle – 500W/3 min, long – 90W/13 min + 500W/90 sec, and manufacturing microwave cycle - 320W/ 3 min + 0W/3 min + 720W/3 min); T (Clássico, water bath cycle – 74°C/9h) and Q (Jet, press chamber cycle – 50°C/15 min at 2 bar). Ten specimens (65 x 10 x 3.3mm) were prepared for each cycle. The flexural strength of the five groups was measured using a three-point bending test at a cross-head speed of 5 mm/min. Flexural strength values were analyzed by one-way ANOVA and the Tukey's test was performed to identify the groups that were significantly different at 5% level. The microwave-polymerized groups showed the highest means (p<0.05) for flexural strength (MPa) (A = 106.97 ± 5.31; B = 107.57 ± 3.99; C = 109.63 ± 5.19), and there were no significant differences among them. The heat-polymerized group (T) showed the lowest flexural strength means (84.40 ± 1.68), and differ significantly from all groups. The specimens of a microwavable denture base resin could be polymerized by different microwave cycles without risk of decreasing the flexural strength.

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Thermocycling decreased the bond strength, but not significantly for microwave and heat-polymerised cycles. Regarding the bond strength of denture teeth to acrylic resin, the fast microwave polymerisation cycle should be avoided when polymerising Onda-Cryl acrylic resin. In addition, Jet acrylic resin is not adequate for use in denture repair.

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The purpose of this study was to evaluate the relationship between Candida and denture wear during the night. Twenty-four edentulous volunteers were randomly divided into two groups. Group I (GI, n = 11) was composed of volunteers who wore their complete dentures day and night and Group II (GII, n = 13) was composed of volunteers who wore their complete dentures only during the day. Three examination periods were performed for both groups. In GI, the first examination (A) was carried out after overnight denture wearing. Subsequent examinations were conducted after one (B) and seven nights (C) without denture use during sleep. In GII, the first (A) was done without previous use during sleep, and the following were carried out after one (B) and seven nights (C) of overnight denture wearing. Total unstimulated saliva was collected in a sterile container and cultured in duplicate inside Petri dishes. The values of colony forming units (CFU mL(-1) +/- s.d.) were obtained: GI A - 10.1 x 10(3) +/- 1.2 x 10(4), B - 2.0 x 10(3) +/- 2.6 x 10(3), and C - 2.6 x 10(3) +/- 5.9 x 10(3) and GII: A - 0.4 x 10(3) +/- 0.6 x 10(3), B - 9.4 x 10(3) +/- 17.7 x 10(3) and C - 6.3 x 10(3) +/- 15.3 x 10(3). The mean counts for Candida sp. were expressed as log (CFU + 1) mL(-1) and statistical significance of differences among groups was tested by anova (alpha = 0.05). Multiple comparisons were performed according to Bonferroni test and indicated significant differences between A-B and A-C, but not between B and C for both groups. It was concluded that there is a significant relationship between continuous denture wear and Candida sp.