Randomized clinical trial of the influence of impression technique on the fabrication of cast metal posts.

STATEMENT OF PROBLEM: Direct and indirect techniques are used for intracanal impression and fabrication of cast metal posts. However, whether those techniques affect the accuracy of cast metal posts is unknown. PURPOSE: The purpose of this randomized clinical trial was to evaluate the accuracy of cast metal posts depending on tooth position and impression technique. MATERIAL AND METHODS: Endodontically treated teeth (anterior or posterior) planned to receive cast metal posts and complete crowns were randomized according to impression technique (direct or indirect). Impressions were made by 2 operators, and time for the impression was recorded. All impressions and cast metal posts were photographed to assess any possible differences between techniques in length of the cast metal post. RESULTS: All cast metal posts were shorter than the impressions. The mean reduction for the metal posts was 2.3% for direct in anterior teeth, 5.7% for direct in posterior teeth, 6.3% for indirect in anterior teeth, and 7.2% for indirect in posterior teeth (all P<.05). Statistically significant differences were found between time of technique and tooth position (P=.031), with the direct technique more time consuming than the indirect technique (P<.001) for both tooth positions. For the indirect technique, the impression times for both tooth groups were similar (P=.459). CONCLUSIONS: Both of the intracanal impression techniques resulted in cast posts that were shorter than the impressed post space. The discrepancy was greatest for the indirect technique. Nevertheless, all posts were considered clinically acceptable and were cemented.

An alternative method for the fabrication of a root-supported overdenture: a clinical report.

The preservation of teeth to support an attachment-retained overdenture is an appropriate and stable alternative to extractions and complete dentures. A key to success is the strategic selection of teeth for retention. This clinical report discusses a method for fabricating an overdenture based on a combination of direct and indirect impression techniques. This technique is a simple and time-efficient alternative to traditional methods that aids in overcoming difficulties in fabricating overdentures.

Effect of triazine derivative added to denture materials on a microcosm biofilm model.

The aim of this study was to assess the effect of triazine incorporation to denture materials on biofilm formation of saliva derived from microcosms of patients who are positive for Candida albicans. Biofilms were formed on microwave-cured acrylic resin, one hard denture liner, and two soft denture liners containing 0, 2.5, 5, and 10% triazine. For experimental subset (n = 10), mechanical properties of the materials and colony-forming unit counts from the biofilms formed on the materials were assessed. Flexural strength and modulus decreased with the addition of 2.5% triazine (p < 0.01). In general, the addition of 5 and 10% triazine leaded to more soluble materials (p < 0.001). Saliva donor with candidiasis resulted in higher counts of total microorganisms (p = 0.0294) and Streptococci (p = 0.0008). Soft denture liners showed the highest counts for total microorganisms, Streptococci, and Candida species (p < 0.001). The addition of triazine directly to denture materials was not beneficial in reducing biofilm formation in a complex biofilm model.