Preventive maintenance: A view of periodontists from Porto Alegre/RS

The aim of the present study was to evaluate the opinion of periodontists from Porto Alegre about aspects related to the understanding the clinical approach to periodic maintenance. Sixty one periodontists registered in the city participated in this study, answering to a questionnaire about how the face periodontal maintenance. The majority (86.9%) thinks that the maintenance interval should be variable, depending on individual characteristics. Risk factors were pointed as the reasons to choose the recall intervals. 73.8% of the interviewed dentists charges the same amount of money for treatment and maintenance appointments and more than 90% thinks that the difference between maintenance and retreatment is linked to disease recurrence. 81.9% of the periodontists performs maintenance in one single visit and the majority considers periodontal disease a disease that can be cured. The analysis of the results leads to the conclusion that the periodontal patient has the opportunity of being treated and maintained in a healthy status. It is important that the periodontista individually know his patient in order to establish the frequency of this maintenance

Elicited bid functions in (a)symmetric first-price auctions

We report on a series of experiments that examine bidding behavior in first-price sealed bid auctions with symmetric and asymmetric bidders. To study the extent of strategic behavior, we use an experimental design that elicits bidders' complete bid functions in each round (auction) of the experiment. In the aggregate, behavior is consistent with the basic equilibrium predictions for risk neutral or homogenous risk averse bidders (extent of bid shading, average seller's revenues and deviations from equilibrium). However, when we look at the extent of best reply behavior and the shape of bid functions, we find that individual behavior is not in line with the received equilibrium models, although it exhibits strategic sophistication.This research benefited from financial support from the European Commission through a TMR-ENDEAR Network Grant (FMRX-CT98-0238) and a Marie Curie Fellowship (Sadrieh: HPMF-CT-199-00312) and from the Deutsche Forschungsgemeinschaft through SFB 303

The Effect of Spironolactone on the Pathogenesis of Ligatureinduced Alveolar Bone Loss in Wistar Rats

Tumor necrosis factor (TNF) is a pro-inflammatory cytokine that has a straight relationship with tissue  destruction in the pathogenesis of periodontitis. Inhibitory effects of TNF production have been attributed  to spironolactone. The aim of this study was to evaluate the effect of spironolactone on the pathogenesis of  ligature-induced alveolar bone loss in rats. Experimental periodontitis was induced in 38 Wistar rats by ligature  placement in the left second maxillary molar. The contra-lateral maxillary molar served as intragroup  control. Animals were randomly divided into 4 groups and treated with spironolactone (50, 100, 200  mg·kg-1) or saline. Morphometrical registration of maxillary alveolar bone was performed after 28 days of  experimental periodontitis. Intra-group comparisons showed significantly higher alveolar bone loss mean  values in maxillary sides with ligature (paired sample t test, p<0.05). Mean alveolar bone loss was not significantly  different between groups, independently of the dosage (range: 0.63 – 0.66 mm, one-way  ANOVA, p>0.05). Although spironolactone has recognized TNF-inhibitory properties, the possibility of its  use on modulation of host immune-inflammatory response in periodontal disease was not confirmed.