ABSTRACT
This study examined the antibacterial activities of the bonding systems Syntac, EBS and Scotchbond 1, the polyacid-modified composite resins Hytac and Compoglass, and the composite resins Tetric, Z100 and Scalp-it. They were evaluated using the cariogenic bacteria Streptococcus mutans, Lactobacillus salivarius, Streptococcus sorbinus and Actinomyces viscosus in vitro with a modified cylinder drop plate agar diffusion assay. All adhesives of the dentin bonding systems and the polyacid-modified composite resins exhibited various degrees of antibacterial activity against all of the test bacteria. On the contrary, composite resins did not affect bacterial growth. The data suggest that the use of these adhesives and polyacid-modified composite resins may reduce the consequences of microleakage owing to their antibacterial properties.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Compomers/pharmacology , Composite Resins/pharmacology , Dentin-Bonding Agents/pharmacology , Silicon Dioxide , Zirconium , Actinomyces viscosus/drug effects , Actinomyces viscosus/growth & development , Composite Resins/chemistry , Dental Leakage/microbiology , Glass Ionomer Cements/chemistry , Humans , Lactobacillus/drug effects , Lactobacillus/growth & development , Methacrylates/chemistry , Phosphoric Acids/chemistry , Resin Cements/chemistry , Streptococcus mutans/drug effects , Streptococcus mutans/growth & development , Streptococcus sobrinus/drug effects , Streptococcus sobrinus/growth & developmentABSTRACT
An ideal cement base material in order to protect the pulpal tissue from several external irritations (microbial, mechanical, thermal, galvanic and osmotic irritations) must present the following requirements: to attach or bond to the residual dentin, to be biocompatible, to present suitable physicomechanical, antimicrobial and optical properties, to be color stable, easy to use and rapid to set. Thermal phenomena developed during the mixing and setting are a factor influencing the biocompatibility properties of these materials. Cement base materials are used under various types of filling materials (amalgams, composite resins, gold and porcelain inlays) and are placed in contact with the dentin that contains exposed dentinal tubules. The purpose of this study was to investigate the possible exothermic reaction of these materials and to measure the developing temperatures for a time period from their mixing up to the completion of their setting. We studied the following types of cement base materials: a) Zinc oxide eugenol cement, b) Zinc phosphate cement, c) Zinc polycarboxylate cement and d) Glass ionomer cement both light- and self-cured. From the obtained results we observed that ZOE cements developed the lowest temperatures ranging from 32.8 degrees C to 37 degrees C, while Zinc phosphate cements developed the highest temperatures ranging from 44.4 degrees C to 52 degrees C. The other two types of materials Zinc polycarboxylate and Glass ionomer cements developed biocompatible temperatures ranging from 38 degrees C to 40.8 degrees C, which usually do not cause deteriorations and harms to the pulp. We concluded that the ZOE cements presented the best thermal behaviour followed by Zinc polycarboxylate and Glass ionomer cements. Hence, these materials can be safely used without causing any pulpal response.
Subject(s)
Biocompatible Materials/chemistry , Dental Cements/chemistry , Hot Temperature , Materials Testing/instrumentation , Materials Testing/methodsABSTRACT
Interfacial tensile bond strengths of self-cured and light-activated composite resins, repaired with the same or another composite resin were measured. The bond strengths were measured as a function of age of the substrate or as a function of the adhered surface treatment. One control group of solid resin samples was tested for tensile strength. Other groups of specimens, matured for 48 hours, 7 days, and 1 year, were cut in half and ground flat before a fresh mass of composite resin was added. Six groups were coated with a thin layer of intermediate resin or bonding agent before the fresh composite resin was added. In general, the repaired composite resins revealed lower strength than did the cohesive samples, with bond strengths ranging from 19% to 52% of the strengths of the unrepaired resins. The intermediate resin increased the bond strength in all cases.
