Influence of intracoronal bleaching agents on the bond strength of MTA cements to composite resin and their surface morphology.

The objective of the present in vitro study was to evaluate micro-tensile bond strength (µSBS) of MTA cements to composite resin using a universal adhesive after internal bleaching procedure, and to examine surface characteristics of MTA cements exposed to bleaching agents. MTA specimens were divided into three subgroups according to the bleaching agent used which were, 37% carbamide peroxide (CP), 35% hydrogen peroxide (HP), and no exposure as a control group (n = 12). After exposure to bleaching agent, composite resins were applied to MTA surfaces using a universal adhesive in self-etch mode. The specimens were exposed to a shear force until failure to evaluate bond strength. MTA surfaces were investigated using scanning electron microscopy (SEM) to observe the effects of the bleaching agents. Differences between groups were analyzed using two-way ANOVA test and intergroup comparisons were assessed with Tukey test (p < 0.05). Although there was a slight difference in bond strength between bleaching agents (CP and HP), no significant difference was found, irrespective of MTA cement. After the HP application, the bond strength values decreased approximately by half compared with the controls. SEM results demonstrated distinct morphological differences between the intact MTA surface (control) and treated MTA surface. Distinct micro-cracks, surface irregularities, and capillary voids formed due to the superficial dissolution caused by peroxides. Exposure to the intra-coronal bleaching agents had a negative influence on the surface morphology of MTA cements and their bond strength to composite resin.

Reaction to at-home air purifiers installed to reduce traffic-related air pollution in near-highway residences.

BACKGROUND AND AIM: Traffic-related ultrafine particle pollution near highways is associated with adverse health. Reducing exposure by use of portable air purifiers in homes is one approach to reducing this risk. However, the reaction of residents to having air purifiers in homes is not well studied. METHODS: Within the framework of our randomized crossover trial of air purifiers in homes near a major highway, we collected data about participants' use and reactions to air purifiers using questionnaires at their 30-day and 90-day home visits, recorded electricity consumption using HOBO monitors, and conducted structured interviews with participants. RESULTS: Nearly all 150 participants reported running the air purifiers virtually 24 h every day in both their living room and their bedroom in the prior month. The units' HOBO electricity use, from a subset of 45 participants, supported the participants' responses from the questionnaire. Approximately 80% of participants reported setting their air purifier on the medium setting. Tolerance to air purifier noise increased significantly between the 30-day and 90-day home visits, with approximately two thirds reporting not being bothered at all by the noise. The qualitative interviews in a subset of 26 participants yielded consistent responses to those from the questionnaires. Size of unit, airflow, and energy consumption were additional concerns that emerged during the interviews. CONCLUSIONS: Results from the questionnaires, HOBO data, and structured interviews all suggest participants had positive reactions towards the presence of in-home APs, and therefore may be receptive to using air purifiers in their homes on a regular basis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04279249 . Registered 09 October 2019.

Clinical and radiographic evaluation of indirect pulp capping with three different materials: a 2-year follow-up study.

AIM: Indirect pulp capping (IPC) is a treatment that preserves pulp vitality. Several materials have been used for this procedure. The aim of this study is to evaluate the radiographic and clinical outcomes of TheraCal LC (Bisco Inc., Schaumburg, IL, USA) and to compare it with mineral trioxide aggregate (MTA) (Pro Root MTA, Dentsply Tulsa, Johnson City, TN, USA) and calcium hydroxide [Ca(OH)2] (Dycal, Dentsply De Trey Konstanz, Germany) biomaterials in IPC treatment. MATERIALS AND METHODS: A total of 295 teeth, including second primary molars and first permanent molars with IPC indications from healthy and cooperative children aged between 4-15 years, were included in this study. Teeth were divided into three groups according to the materials used for pulp capping. Indirect pulp treatment was applied using Dycal for 91 teeth, ProRoot MTA for 89 teeth and TheraCal LC for 115 teeth. Primary molars were restored with the compomer material, and permanent molars were restored with the resin composite material. Restorations were evaluated with the Modified United States Public Health Service (modified USPHS) criteria. Clinical and radiographic findings were evaluated for 24 months at follow-up. STATISTICS: Statistical analysis was performed using the IBM SPSS Statistics 22 (IBM SPSS, Turkey) program, with descriptive statistical methods (means, standard deviations) and Chi-square, Fisher's exact test, and Yates's continuity correction (p<0.05 significance level) to evaluate the data. RESULTS: There were no statistically significant differences between the materials (p>0.05). The respective success rates of ProRoot MTA, Theracal LC, and Dycal were 94.4%, 87.8%, and 84.6%. There was no statistically significant difference between primary and permanent teeth according to the modified USPHS criteria (p>0.05). CONCLUSION: These results support the idea that the success of IPC is independent from the capping material. Recently produced calcium-silicate based materials can also be used for IPC. The most important factors are to apply the indirect pulp treatment carefully, avoiding bacterial contamination, and to seal the teeth with hermetic restoration. More clinical studies with longer follow-up periods are required for understanding the clinical efficiency of these materials.

[Microorganisms growing on the inner surfaces of prefabricated houses and their control]. / Prefabrik konutlarin iç yüzeylerinde gelisen mikroorganizmalarin tesbiti ve önlenmesi üzerine arastirmalar.

Microorganisms which isolated from the plasters of prefabricated houses, constructed by Yübetas company in Oran Ankara Were examined. As a result of isolations, Alternaria, Penicillium and Stemphylium species of fungi were founded on the plasters. The growth of the fungi was tested on Agrisan megess and Dyo Sadosan make plastic wall paints and it was found that these fungi showed a profuse growth in the former make paint, but not in the second one. When mancozeb (Dithan-M-45) in 0.2% and copper oxychloride (Mavi Bakir Sandoz) in 0.5% were added to the plaster the growth of the fungi were completely prevented, but Wettable powder sulfur in 0.4% did not prevent their growth but stimulated it.