Residual Infestation and Recolonization during Urban Triatoma infestans Bug Control Campaign,Peru

Chagas disease vector control campaigns are being conducted in Latin America, but little is known about medium-term or long-term effectiveness of these efforts, especially in urban areas. After analyzing entomologic data for 56,491 households during the treatment phase of a Triatoma infestans bug control campaign in Arequipa, Peru, during 2003–2011, we estimated that 97.1% of residual infestations are attributable to untreated households. Multivariate models for the surveillance phase of the campaign obtained during 2009–2012 confirm that nonparticipation in the initial treatment phase is a major risk factor (odds ratio [OR] 21.5, 95% CI 3.35–138). Infestation during surveillance also increased over time (OR 1.55, 95% CI 1.15–2.09 per year). In addition, we observed a negative interaction between nonparticipation and time (OR 0.73, 95% CI 0.53–0.99), suggesting that recolonization by vectors progressively dilutes risk associated with nonparticipation. Although the treatment phase was effective, recolonization in untreated households threatens the long-term success of vector control.     

Microbial succession in recolonizing deep periodontal pockets after a single course of supra- and subgingival debridement

In the present study, the effect of supra and subgingival plaque debridement on the dynamics of the subgingival microflora in deep pockets was investigated. 8 adult periodontitis patients participated in the study. In each patient, 4 clinically diseased sites were investigated microbiologically by phase contrast microscopy for the determination of both the %s as well as the total numbers of spirochetes and motile rods and by anaerobic cultivation for the determination of the different black-pigmented Bacteroides species. After base-line examination, patients were treated by mechanical removal of supra- and subgingival plaque deposits. 2 and 8 weeks after treatment, clinical and microbiological parameters were re-evaluated. During the experimental period, no oral hygiene procedures were performed in order to achieve fast recolonization of the pockets. Treatment resulted in a significant reduction in probing pocket depth and gain of probing attachment. 2 weeks after treatment, no further improvements could be observed. A positive correlation was found between the reduction in probing pocket depth and decrease in Bacteroides gingivalis (P less than 0.009) and between gain in probing attachment and reduction in the % of B. gingivalis (P less than 0.009). No correlation between these clinical parameters and B. intermedius, spirochetes or motile rods was apparent. An inverse relationship between B. gingivalis and B. intermedius was observed. We found that changes in %s of spirochetes and motile rods are not correlated with changes in total numbers of these bacterial groups. It was concluded that monitoring of %s of micro-organisms may not supply rational information on the microbiological conditions of the subgingival area.     

Microbiological and clinical effects of an antiseptic dental varnish after mechanical periodontal therapy

The aim of this study was to explore the microbiological and clinical effects of an antiseptic dental varnish when applied to periodontally diseased teeth after mechanical therapy. 20 subjects participated in this placebo controlled, double blind prospective longitudinal study. 2 experimental sites with a pocket probing depth > or =5 mm were chosen in each subject. The control varnish, consisting of ethanol, ethylacetate and polyvinylbutyral, was applied to one of the selected teeth and the test varnish, containing 1% chlorhexidine and 1% thymol in addition, was applied to the other one. Clinical parameters were assessed, and microbiological samples were obtained from the two study sites at baseline (6-10 weeks after completion of conventional periodontal therapy), and 2, 4 and 12 weeks thereafter. The mean PLI at baseline was very low and, therefore, only a minimal potential for a further improvement existed. During the 12-week observation period, the mean PLI increased significantly at sites treated with the placebo varnish, while no similar trend for an increase in PLI was detected in the test sites. The bleeding tendency seemed to remain unaffected by the application of the varnish. On the microbiological level, no relevant differences could be detected between placebo and test sites at baseline, or during the follow-up period. In conclusion, the application of a dental varnish with antimicrobial properties after mechanical periodontal therapy had little effect in subjects with good oral hygiene.     

磷酸钙生物陶瓷的孔性、内部连通性及表面形态对骨质再生的影响

磷酸钙生物陶瓷是一类具有良好生物相容性和骨传导性的生物活性材料,由于其成分与骨的无机组分基本相当,是目前公认的最具前途的硬组织修复材料,将该材料制成多孔结构,更有利于新生骨组织生长所需的物质交流,促进新生骨形成,因而成为近年来生物材料的研究热点之一。本文从多孔磷酸钙生物陶瓷与组织的响应关系角度出发,评述了近年来磷酸钙生物陶瓷的孔性、孔和孔间的内部连通性及孔的表面形态对骨质再生影响的研究进展。