The effect of a novel crystallised bioactive glass-ceramic powder on dentine hypersensitivity: a long-term clinical study.

The aim of this comparative clinical study was to evaluate a novel bioactive glass-ceramic (Biosilicate® 1-20 µm particles) to treat dentine hypersensitivity (DH). Volunteers (n = 120 patients/ 230 teeth) received the following treatments: G1-Sensodyne® , G2-SensiKill®, G3-Biosilicate® incorporated in a 1% water-free-gel and G4-Biosilicate® mixed with distilled water at 1:10 ratio. G1 and G3 were applied at home, daily for 30 days; G2 and G4 were applied once a week by a dentist (four applications). A visual analogue scale (VAS) was employed to evaluate pain for each quadrant in one sensitive tooth at baseline, weekly during treatment and during a 6-month follow-up period. Dentine hypersensitivity values (G1/n= 52), (G2/n =62), (G3/n = 59) and (G4/n = 59) were analysed with Kruskal-Wallis/Dunn tests. All the products were efficient in reducing DH after 4 weeks. Among the four materials tested, G4 demonstrated the best clinical performance and provided the fastest treatment to reduce DH pain. Distilled water proved to be an adequate vehicle to disperse Biosilicate®. Low DH scores were maintained during the 6-month follow-up period. The hypothesis that the novel bioactive glass-ceramic may be an efficient treatment for DH was confirmed.

Preparation and antimicrobial activity of gelatin microparticles containing propolis against oral pathogens.

Gelatin microparticles containing propolis ethanolic extractive solution were prepared by spray-drying technique. Particles with regular morphology, mean diameter ranging of 2.27 microm to 2.48 microm, and good entrapment efficiency for propolis were obtained. The in vitro antimicrobial activity of microparticles was evaluated against microorganisms of oral importance (Enterococcus faecalis, Streptococcus salivarius, Streptococcus sanguinis, Streptococcus mitis, Streptococcus mutans, Streptococcus sobrinus, Candida albicans, and Lactobacillus casei). The utilized techniques were diffusion in agar and determination of minimum inhibitory concentration. The choice of the method to evaluate the antimicrobial activity of microparticles showed be very important. The microparticles displayed activity against all tested strains of similar way to the propolis, showing greater activity against the strains of E. salivarius, S. sanguinis, S. mitis, and C. albicans.

Tensile bond strength of a polymeric intra-buccal bioadhesive: the mucin role.

The intra-bucal polymeric bioadhesive systems that can stay adhered to the oral soft tissues for drug programmed release, with the preventive and/or therapeutic purpose have been employed for large clinical situations. A system based on hydroxypropyl methyl cellulose/Carbopol 934TM/magnesium stearate (HPMC/Cp/StMg), was developed with the sodium fluoride as an active principle. This kind of system was evaluated according to its resistance to the removal by means of physical test of tensile strength. Swine buccal mucosa extracted immediately after animals' sacrifice was employed as a substrate for the physical trials to obtain 16 test bodies. Artificial saliva with or without mucin was used to involve the substrate/bioadhesive system sets during the trials. Artificial salivas viscosity were determined by means of Brookfield viscometer, and they showed 10.0 cP artificial saliva with mucin, and 7.5 cP artificial saliva without mucin. The tensile strength assays showed the following averages: 12.89 Pa for the group "artificial saliva with mucin", and 12.35 Pa for the group "without mucin". Statistical analysis showed no significant difference between the assays for both artificial salivas, and we can conclude that the variable mucin did not interfere with the bioadhesion process for the polymeric devices.

Capacity of denture plaque/biofilm removal and antimicrobial action of a new denture paste.

The efficacy of a paste for complete dentures was analyzed in terms of denture plaque/biofilm removal and antimicrobial action against specific microorganisms by determination of colony forming units of mutans group streptococci and yeast from 120 full denture wearers with a healthy palatine mucosa. The patients were given a questionnaire to evaluate the experimental product in terms of important characteristics. The paste was widely accepted by the patients, and effective in denture plaque removal and antimicrobial action. The species of yeasts most frequently isolated were C. albicans, C. tropicalis and C. glabrata. We conclude that it is possible for complete denture wearers to keep their dentures clean with the regular use of a paste-like hygienic product.

Comparative bioavailability of sulfamethoxazole in co-trimoxazole suspensions containing different thickness agents.

Many workers have attempted to determine the bioavailability of pharmaceutical formulations, which is important to assure the efficacy and safety of medications. In the present study, we investigated the bioavailability of five formulations of the combination of 0.8% trimethoprim (TMP) and 4% sulfamethoxazole (SMZ) (co-trimoxazole) as a suspension, containing different types of thickness agents. The blood levels of a single oral dose administered to rats were compared. Bioavailability was determined by comparing the time to peak concentration (Tmax), peak serum concentration (Cmax), total area under the concentration time curve (AUC) and the elimination rate constant (Kel). Analysis of the pharmacokinetic parameters of SMZ showed significant differences between the formulations, indicating that the absorption of SMZ was affected by thickness type. The calculated bioavailabilities of oral TMP and SMZ were 381, 558, 695, 480, 559 and 554 micrograms/mL, respectively, and the preparation containing hydroxyethyl cellulose 4.400 H as a thickness agent showed the best bioavailability (AUC 0-infinity = 695.24; micrograms/mL; Cmax = 35.2 micrograms/mL).