The three-point bending test of fiber-reinforced composite root canal posts.

BACKGROUND: The primary reason for using a post is to retain the core with the objective to restore the missing coronal tooth structure. To achieve optimum results, the materials that are used to restore endodontically treated teeth should have physical and mechanical properties that are similar to that of dentin. OBJECTIVES: To characterize the strength parameters of fiber-reinforced composite (FRC) posts with the application of a three-point test. The mean fracture load, flexural strength and flexural modulus were taken into consideration. MATERIAL AND METHODS: For the three-point strength tests, 5 kinds of fiberglass root-posts were used: GC Fiber Post (GC America, Alsip, USA), Mirafit White (Hager Werken, Duisburg, Germany), Innopost (InnoTech, Verona, Italy), Rebilda Post (Voco, Cuxhaven, Germany), and EverStick Post (GC Europe, Leuven, Belgium). For each system, 15 FRC posts were tested. All posts had the same diameter, length and shape. The three-point test was carried out in accordance with ISO 10477:2004, using the Instron-5944 testing machine (Instron, Norwood, USA). The test was carried out until the sample was broken. RESULTS: The highest force values (67.6 N) were recorded for the GC posts, and the lowest force required to break the sample (29.6 N) was noted for the EverStick Posts. In the case of bending strength, the highest values were also recorded for GC posts (912.4 MPa). Low bending strengths were obtained for the Mirafit White posts (537.2 MPa); however, the EverStick Posts were the weakest (436.2 MPa). Rebilda posts showed the highest modulus of elasticity - 31.1 GPa. The lowest values of the elastic modulus were registered for EverStick Posts - 12.5 GPa. CONCLUSIONS: There were statistically significant differences in fracture loads, flexural strengths and flexural modulus of the FRC-post systems tested. Individually polymerized FRC material showed lower flexural properties than compared prefabricated FRC posts.

A clinical evaluation denture adhesives used by patients with xerostomia.

The purpose of study was to analyze the participants' opinions concerning the effectiveness of 6 denture adhesives (DA). The study group included 60 participants. Criteria for selecting the patients were as follows: reduced retention and stabilization of maxillary complete dentures and xerostomia. These features were evaluated on basis of clinical examination and standard sialometry tests (u-SFR). Retention of maxillary dentures was scored by modified Kapur index before application of DA. All participants were divided randomly into 6 groups regarding the use of the 6 DA during a 6-month period. After this time, participants completed an HRQL questionnaire. DA noticeably improved retention and stabilization of maxillary complete dentures. DA in the glue form had the best retention effectiveness in participants with xerostomia. These materials are difficult to clean from the denture base. The data are presented in tables and figures. The results of the study collected positive influence of adhesives on retention of dentures in xerostomia patients. The cleaning dentures and denture bearing tissues was difficult. DA help in the use of prostheses, but it is also necessary for the treatment of the causes and symptoms of xerostomia.

Follow-up visits as a measure of adaptation process to removable prostheses.

OBJECTIVES: The paper was aimed to establish the influence of some general and local factors on adaptation process to removable prostheses (RPs). The adaptation process is a complex issue, which is often associated with painful reactions. Those complaints force patients to visit a dentist who makes alterations to reduce the patient's discomfort. MATERIAL AND METHODS: The study involved analysis of 300 dental records of patients who visited our Department for RPs. The authors analysed the influence of gender, age, condition of general health, maintenance of the prosthetic base tissues and the kind of prostheses on the process of adaptation. It was measured by means of a number of follow-up visits of the patients to our polyclinic. The findings were analysed statistically by means of chi-squared test. The level of significance was assumed to be p < 0.05. RESULTS AND CONCLUSIONS: Adaptation to RPs without any correction was revealed by about one-fifth of patients. Men adapted to RPs better than women. The biggest problems with adaptation to RPs were observed in patients using a complete and partial prosthesis simultaneously. The number of follow-up visits by patients who were treated with RPs for the first time or had been treated before was almost the same. Adaptation of RPs on an atrophic muco-osseous ridge was associated with more multiple visits than in the case of a well-preserved ridge. Healthy patients adapt to RPs better than patients with systemic disorders. Taking into account the limitations of the study, the number of follow-up visits may be used as a helpful indicator of the adaptation process.