Do dental impression materials play a role in cross contamination?

OBJECTIVE: Dentists are required to institute infectious control procedures. Dental impression materials possessing antimicrobial properties may aid in reducing the risk of cross contamination since impression materials might play a role as carriers. The purpose of this study was to evaluate the antimicrobial properties of four impression materials. METHOD AND MATERIALS: Four impression materials--Orthoprint, Impregum Penta, Aquasil Ultra Monophase, and Permlastic--were evaluated by the direct contact test. The materials were tested in contact with Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. The materials were mixed; allowed to set; and examined immediately and after aging for 24, 48, and 72 hours and 1 week. Two-way ANOVA, one-way ANOVA, and Tukey multiple comparison procedures were applied to the results. RESULTS: Impregum Penta presented the broadest antibacterial spectrum of all the materials tested. There was a complete growth inhibition of S aureus and S epidermidis, and it sustained this ability for at least 7 days. It also showed an antifungal effect by partially inhibiting the growth of C albicans, a quality that was seen only immediately after setting. Aquasil Ultra showed an antifungal effect only immediately after setting. Permlastic showed a complete growth inhibition when in contact with C albicans and sustained this ability for at least 7 days. No significant antimicrobial properties were recorded for Orthoprint. When in contact with E faecalis, no significant antibacterial properties were recorded for any of the materials. CONCLUSION: None of the tested materials exhibited a long-lasting or complete antibacterial and antifungal property. Therefore, disinfection of impressions is essential.

In vitro antibacterial evaluation of flowable restorative materials.

OBJECTIVES: The microgap at the tooth-restoration interface is inevitable and may allow bacterial penetration that could lead to failure. The purpose of this in vitro study was to assess the antibacterial potential of 4 flowable composite restorative materials. METHOD AND MATERIALS: The antibacterial potential of Aeliteflo (Bisco), Filtek Flow (3M ESPE), Tetric Flow (Ivoclar Vivadent), and Dyract Flow (Dentsply) was tested against Streptococcus mutans. Agar diffusion test (ADT) and direct contact test (DCT) were the methods used. For ADT, wells were punched in S mutans-inoculated plates. The materials were placed in the wells and polymerized. Inhibition zones were measured after 48 hours' incubation at 37 degrees C. In the DCT, 8 samples of each tested material were placed on the side walls of wells in a 96-microtiter plate and polymerized. A suspension of S mutans was placed on the surface of each sample. Bacterial growth was monitored by optical density changes at 650 nm every 30 minutes for 16 hours. The experiment was repeated after the samples were aged in phosphate-buffered saline for 1 and 7 days. RESULTS: In both tests, only Dyract Flow showed inhibition of S mutans growth. Except for Dyract Flow samples, aged samples did not statistically differ in S mutans inhibition when compared to their 1-hour control counterparts. Dyract Flow samples lost their S mutans inhibitory potential after 24 hours. CONCLUSION: The flowable composites tested do not possess effective long-term antibacterial ability.

Restoration of endodontically treated teeth review and treatment recommendations.

Coronal restorations and posts can positively influence the long-term prognosis of teeth following root canal therapy. Final sealing the canal by placing an appropriate post and core will minimize leakage of oral fluids and bacteria into the periradicular area and is recommended as soon as possible after completion of root canal filling. Glass ionomer or MTA placed over the residual root canal filling after post space preparation may be effective to prevent bacterial leakage. A ferrule of 1-2 mm of tooth tissue coronal to the finish line of the crown significantly improves the fracture resistance of the tooth and is more important than the type of the material the core and post are made of.

Fracture resistance of endodontically treated teeth restored with combined composite-amalgam restorations.

OBJECTIVE: To evaluate the resistance to fracture of endodontically treated teeth restored with combined composite-amalgam restorations in comparison to all-amalgam restorations. METHOD AND MATERIALS: Forty-eight human premolar teeth were equally divided into 4 groups. Mesio-occlusodistal (MOD) cavities were prepared in 3 groups, and in the fourth group, a modified MOD preparation was designed with an additional buccolingual groove. All teeth were endodontically treated and restored using 1 of several restorative modalities: all amalgam (AM), all amalgam plus dentin adhesive (ADA), amalgam plus dentin adhesive plus composite resin (ADAC), and amalgam plus dentin adhesive plus composite resin with a modified preparation design (ADACM). Specimens were tested in a universal testing machine (Instron). The load (in kilonewtons) at fracture was recorded and statistically analyzed using a Bonferroni one-way statistical analysis (significance: P

Endodontic failure caused by inadequate restorative procedures: review and treatment recommendations.

A review of the literature was performed to determine whether prompt placement of coronal restorations, including sealing and placement of posts and cores, can positively influence the long-term prognosis of teeth after root canal therapy. Both hand and MEDLINE searches were employed to identify peer-reviewed articles on radicular apical integrity after coronal restorations, especially where root canal space was used for post and core fabrication. A total of 41 articles published between 1969 and 1999 (the majority from the 1990s) were reviewed. The literature suggests that the prognosis of root canal-treated teeth can be improved by sealing the canal and minimizing the leakage of oral fluids and bacteria into the periradicular areas as soon as possible after the completion of root canal therapy.