Evaluation of chemical-physical properties and cytocompatibility of TheraCal LC.

TheraCal LC (TLC, Bisco Inc., Schaumburg, IL, USA) is a light-cured, resin-modified, calcium silicate-filled base/liner material designed for direct and indirect pulp-capping. In this study the result of the evaluation in vitro of the biocompatibility and chemical-physical properties of TLC are reported. TLC specimens were prepared under aseptic conditions in strict compliance with the manufacturer’s instructions and sterilized. Osteoblast-like cells (MG63) were used. For different time points, solubility, water uptake, alkalinizing activity and cytotoxicity were evaluated. In ddH20 and in DMEM+FBS, TLC showed a loss of material increasing simultaneously with the absorption capacity. The increase of water uptake of the material promoting the solubilization of mineral ions in medium is a requisite for a bioactive material. The alkalinizing activity is correlated to antimicrobial/bacteriostatic activity and to the ability to favor the formation of apatite deposits. The pH values for water absorption after immersion of the disks ranged between 8 and 9 at each times of evaluation. Cytotoxicity was not observed in MG63 cells treated with TLC and after 5 days, the cells were organized to form a confluent monolayer as demonstrated by fluorescence microscopy observation. TLC showed biocompatibility on MG63 cells allowing a physiologic cell growth and differentiation. The chemical-physical properties and biocompatibility of TLC observed in vitro in the present study, allows considering this cement as an innovative pulp-capping material for the vital pulp therapy.

Periodontal disease associated with red complex bacteria in dogs.

OBJECTIVE: Red complex bacteria (Treponema denticola, Tannerella forsythia and Porphyromonas gingivalis) play a major role in the aetiology of periodontal disease in humans. This study was designed to evaluate the association of such bacteria with periodontal disease in dogs. METHODS: Seventy-three subgingival samples taken from dogs ranging from 2 months to 12 years (median age 4 years) were tested for red complex bacteria using a polymerase chain reaction assay. RESULTS: Thirty-six of 73 (49 · 3%) dogs were found to be positive for T. forsythia and P. gingivalis. Dogs with gingivitis or periodontitis were more likely to be infected with T. forsythia and P. gingivalis [odds ratio (OR) 5 · 4 (confidence interval (CI) 1 · 9-15 · 6), P = 0 · 002] than healthy animals. Only 3 (4 · 1%) of 73 samples were positive for red complex bacteria, but the association with periodontal disease was not significant. CONCLUSION AND CLINICAL RELEVANCE: The results indicate that involvement of red complex bacteria in periodontal disease in dogs is similar to that observed in humans. Only the concurrent presence of T. forsythia and P. gingivalis were correlated to periodontal disease in dogs in this study.

Methicillin-resistant staphylococci carriage in the oral cavity: a study conducted in Bari (Italy).

OBJECTIVES: The oral cavity may represent a site of colonization by antibiotic-resistant bacteria, such as methicillin-resistant staphylococci (MRS). To define the prevalence of staphylococci and MRS in the oral cavity, an observational study was carried out in the city of Bari (Italy). METHODS: Sixty subjects were asked to provide oral samples and a questionnaire about risk factors of colonization by MRS. An enrichment medium specific for staphylococci was used for the isolation. RESULTS: Swabs and corresponding questionnaires were available from 36 out of 60 patients. Staphylococci were isolated from seven out of 36 samples (prevalence 19.4%). Among the seven staphylococcal isolates, three were Staphylococcus aureus, and one strain, belonging to S. epidermidis species, was found to be MR (1.7%). No methicillin-resistant S. aureus were isolated. Five out of seven staphylococcal isolates exhibited resistance to more than two classes of non-beta-lactams antimicrobials. None of the risk factors analysed correlated with the status of MRS carriers, except the presence of oral disease. CONCLUSIONS: The results underline the potential role of the oral cavity as a reservoir of staphylococci.