Microbiological Comparison of Different Sealing Materials for the Access Holes of Implant Restorations.

PURPOSE: To evaluate the performance of sealing materials used in the screw-access holes of screw-retained implant final superstructures in vivo and in vitro. MATERIALS AND METHODS: Twenty-one screw-access holes in the final superstructures were randomly divided into three groups (each group, n = 7). Following disinfection and isolation, all access holes were initially filled with sterilised cotton pellets of the same weight. Depending on the group, the access holes were finally sealed with either provisional composite restorations (group A), self-curing resin for provisional sealing (group B), or acrylic resin (group C). After one month of the functional period, the inner cotton pellets were collected as bacterial reservoirs. RESULTS: Total aerobic bacteria and total gram-negative anaerobic bacteria were measured after bacterial culture for 48 h and 72 h, respectively. In vitro evaluation of porosity using scanning electron microscopy (SEM) was also performed. Samples from superstructures sealed with provisional composite restorations showed fewer bacteria and less porosity than samples from superstructures sealed with self-curing resin for provisional sealing and acrylic resin. In this study, provisional composite restorations showed the best sealing properties. Provisional composite restorations may prevent bacterial invasion of the access holes of the final superstructures. CONCLUSION: In this study, provisional composite restorations showed the best sealing properties. Provisional composite restorations may prevent bacterial invasion of the access holes of the final superstructures.

Evaluation of a Cetylpyridinium Chloride-, Dipotassium Glycyrrhizinate-, and Tranexamic Acid-based Mouthwash after Implant Placement: A Double-blind Randomised Clinical Trial.

PURPOSE: To evaluate the positive effects of a CPC-, GK2-, and TXA-based (CPC/GK2/TXA) mouthwash after implant placement. MATERIALS AND METHODS: Twenty patients (n = 20) who underwent posterior implant-placement surgery were randomly and evenly allocated to the study or the placebo group. After the mouthwash was used 3x/day for 7 to 10 days postoperatively, sutures were analysed by counting the colony-forming units (CFU) for total aerobes, total G [-] anaerobes, total enterobacteria and total H. influenzae, followed by Real-Time PCR of bacterial-specific DNAs of A. actinomycetemcomitans, P. gingivalis, T. forsythia, T. denticola, P. intermedia, P. micra, F. nucleatum, C. rectus, and E. corrodens. In vitro resistance of P. gingivalis, S. aureus, and P. aeruginosa was analysed. The compatibility of the mouthwash with Straumann SLA implant surfaces was evaluated by scanning electron microscopy (SEM). RESULTS: Sixteen patients (n = 16) completed the trial. A statistically significantly greater number of CFU was found in the placebo group for almost all species, especially for total G [-] anaerobes. No statistically significant in vitro resistance was found for P. gingivalis, S. aureus, and P. aeruginosa. SEM revealed no surface alteration after exposure to the mouthwash. CONCLUSION: The use of a CPC/GK2/TXA mouthwash inhibited propagation of the bacteria extracted from the post-surgical sutures after implant placement.

Homogeneous dihydroxylation of olefins catalyzed by OsO(4)(2-) immobilized on a dendritic backbone with a tertiary nitrogen at its core position.

OsO(4)(2-) immobilized on a poly(benzyl ether) dendrimer with a tertiary nitrogen at its core position efficiently catalyzed the homogeneous dihydroxylation of olefins with a low level of osmium leaching. The dendritic osmium catalyst could be applied to the wide range of olefins. Furthermore, the dendritic osmium catalyst was recovered by reprecipitation and then reused up to five times.