Adhesive luting of orthodontic devices to silica-based ceramic crowns-comparison of shear bond strength and surface properties.

OBJECTIVES: The aim of this study was to analyse the impact of different clinical conditioning approaches and an ammonium polyfluoride- and trimethoxysilylpropyl methacrylate-based experimental primer for intraoral luting of buccal tubes on silica-based ceramic surfaces. MATERIALS AND METHODS: A total of 60 leucite-reinforced glass ceramic molar crowns were conditioned using different methods (n = 10): I-roughening, hydrofluoric acid, silane; II-roughening, silane; III-roughening, experimental coupling agent; IV-experimental coupling agent; V-roughening; VI-no treatment. A buccal tube was adhesively luted to the ceramic surface. Subsequently, water storage, thermocycling and chewing simulation were carried out. The shear bond strength (SBS) was determined, and changes in the surface were assessed. RESULTS: All tubes of the control group (group VI) debonded after incubation. The conditioning methods using coupling agents revealed mean values for SBS of 61.56 MPa (group I), 45.53 MPa (group III), 41.65 MPa (group II), and 23.14 MPa (group IV). In groups I-III, both composite residues and cracks/tear-outs were detected. CONCLUSIONS: The conditioning of silicate ceramic surfaces with a suitable coupling agent system appears to allow sufficient adhesive luting of buccal tubes. The intraoral luting of fixed appliance elements on silicate ceramic surfaces using an ammonium polyfluoride- and trimethoxysilylpropyl methacrylate-based ceramic primer can withstand orthodontic forces. CLINICAL RELEVANCE: Ammonium polyfluoride- and trimethoxysilylpropyl methacrylate-based ceramic primers revealed promising results for the intraoral adhesive luting of orthodontic devices to silica-based ceramic crowns.

The Impact of the COVID-19 Pandemic on Avoidance of Health Care, Symptom Severity, and Mental Well-Being in Patients With Coronary Artery Disease.

The COVID-19 pandemic affected regular health care for patients with chronic diseases. However, the impact of the pandemic on primary care for patients with coronary artery disease (CAD) who are enrolled in a structured disease management program (DMP) in Germany is not clear. We investigated whether the pandemic affected primary care and health outcomes of DMP-CAD patients (n = 750) by using a questionnaire assessing patients' utilization of medical care, CAD symptoms, as well as health behavior and mental health since March 2020. We found that out of concern about getting infected with COVID-19, 9.1% of the patients did not consult a medical practitioner despite having CAD symptoms. Perceived own influence on infection risk was lower and anxiety was higher in these patients compared to symptomatic CAD patients who consulted a physician. Among the patients who reported chest pain lasting longer than 30 min, one third did not consult a medical practitioner subsequently. These patients were generally more worried about COVID-19. Patients with at least one worsening CAD symptom (chest pain, dyspnea, perspiration, or nausea without apparent reason) since the pandemic showed more depressive symptoms, higher anxiety scores, and were less likely to consult a doctor despite having CAD symptoms out of fear of infection. Our results provide evidence that the majority of patients received sufficient medical care during the COVID-19 pandemic in Germany. However, one in ten patients could be considered particularly at risk for medical undersupply and adverse health outcomes. The perceived infection risk with COVID-19 might have facilitated the decision not to consult a medical doctor.

A Glass Fiber-Reinforced Resin Composite Splint to Stabilize and Replace Teeth in a Periodontally Compromised Patient.

Combined periodontal and prosthodontic treatment demands of patients require a structured coordination of pretreatments and an adequate choice of restorations. This is especially true if multiple teeth are missing and insufficient crown-root ratios are obvious. A 40-year-old patient with a severe periodontitis (Stage IV, Grade C) was treated with active, nonsurgical periodontal therapy. Afterwards, a supportive periodontal therapy was provided with a recall interval of three to four months. Due to a high tooth mobility of the anterior teeth in the upper jaw and a missing left canine, a combination of a resin composite (Signum composite, Kulzer, Hanau, Germany) and a unidirectional glass prepreg fiber (Tender Fiber Quattro, MICERIUM, Avegno, Italy) was utilized to fabricate a splint in a labside approach to stabilize the remaining teeth. Moreover, an artificial denture tooth was adhesively luted to the splint. A temporary polymer-based material (Vita CAD-Temp, VITA Zahnfabrik, Bad Säckingen, Germany) was selected to supply the posterior teeth of the patient with a 3-unit fixed dental prosthesis (FDP), and both restorations were adhesively cemented. 19 months after insertion, a fracture of the fiber-reinforced resin composite splint occurred that was intraorally repaired. In spite of the fracture of the splint, all materials were functionally and esthetically stable over the follow-up period of 22 months.