Endodontic treatment-related antibiotic prescribing patterns of South African oral health professionals

AIMTo assess the antibiotic prescribing patterns of South African dentists for patients undergoing endodontic treatment. METHODOLOGY This study used data from 2013 health insurance claims submitted by South African oral health professionals to determine the antibiotic prescribing patterns related to endodontic treatment. A logistic regression model was used to test the fully adjusted statistical significance of the association between the exploratory variables (gender, age group, event type, abscess treatment, chronic health) and the dependent variable (antibiotic prescription). Odds ratios with 95% confidence intervals (CI) are reported, and a 95% CI excluding 1 was considered statistically significant. RESULTS Almost 10% of endodontic treatments were prescribed an antibiotic. There were no significant differences in prescribing patterns by gender, age and chronic health status. Prescriptions were more common at the preparatory stage (9.4%) of root canal treatment compared to the therapy (4.7%) and canal filling (2%) stages. Patients who received apical surgery (OR = 2.28; 95% CI 1.38–3.76) and treatment of an abscess (OR = 2.57; 95% 1.82–3.63) had a significantly increased odds of being prescribed an antibiotic. Almost three-quarters of prescriptions were for narrow spectrum antibiotics. CONCLUSION The frequency of antibiotic prescribing by South African dental practitioners for patients undergoing endodontic treatment is relatively low and predominantly involved narrow spectrum antibiotics. It, however, remains important that antibiotics are only prescribed when clinically essential, such as when there are obvious systemic effects. These include fever above 37 degrees, malaise, lymphadenopathy, trismus, increase swelling, cellulitis, osteomyelitis and persistent infection. The wider dissemination and adherence to clear evidence-based prescribing guidelines for antibiotics in this clinical area are important.IS

Fatigue behavior of CAD-CAM composites versus lithium disilicate glass-ceramic.

peer reviewed[en] OBJECTIVE: To assess the fatigue properties of four CAD-CAM composites and compare them with lithium disilicate glass-ceramic. METHODS: The materials studied were: Brilliant Crios (BRI); Cerasmart 270 (CER); Grandio (GRN); and Tetric CAD (TET), and a lithium disilicate glass-ceramic (IPS e.max CAD, EMX) as a reference. Blocks were cut into bars and used for: 1) 3-point flexural test (n = 30/material); and 2) constructing S-N curves (n = 35/material). Fatigue tests were conducted in 36 °C water bath at a frequency of 1 Hz lasting up to 3 × 106 cycles. The S-N curves were plotted using the Basquin model, assuming a distribution of fatigue life following the Weibull statistics. Digital microscopy was used to study the creep of a runout composite sample (CER), and fractured surfaces of selected samples were analyzed using laser confocal microscopy and scanning electron microscopy. RESULTS: Compared to EMX, CAD-CAM composites have a shorter lifespan but comparable fatigue degradation (fatigue to flexural strength ratios) at 5 × 104 cycles (0.57-0.65 versus 0.58). Their slow crack growth parameter (n) were close, ranging from 10.4 to 13.3 for CAD-CAM composites and 14.2 for EMX. Fatigue data of CAD-CAM composites showed less variability than EMX. Creep was detected in CAD-CAM composites at 3 × 106 cycles. SIGNIFICANCE: Despite CAD-CAM composites having shorter lifetimes than EMX, they show similar resistance to fatigue degradation. Time-dependent factors seem to significantly influence composites fatigue at lower stress levels. Thus, extended fatigue testing in water, despite being time-consuming and costly, is essential for understanding material behavior under clinical conditions

The effect of different storage media on the monomer elution and hardness of CAD/CAM composite blocks

ObjectiveThis study aimed to assess the effect of different storage media on the hardness and monomer elution of CAD/CAM composite blocks.MethodsFive resin-composite blocks (RCB), one polymer-infiltrated ceramic network (PICN) block (Enamic (EN)), one ceramic-filled poly ether ether ketone (PEEK) block (Dentokeep (DK)), and one feldspathic ceramic block. Microhardness was measured using a Vickers indenter tester (FM-700, Future Tech Corp., Japan). In addition 4 conventional resin-composites were investigated for monomer elution using high performance liquid chromatography (HPLC) after storage in different media for 3 months. The data were analysed by three-way ANOVA, two-way ANOVA, one-way ANOVA, Tukey’s post hoc test and the independent t-test (α = 0.05 for all tests).ResultsThe specimens stored in the water had a hardness reduction ranging from 0.9% to 24.4%. In artificial saliva, the specimens had a hardness reduction ranging from 2.8% to 23.2%. The hardness reduction percentage in 75% Ethanol/Water (E/W) ranged between 3.8% and 35.3%. All materials, except GR (resin-composite block) and DK (Polyetheretherketone (PEEK)), showed a variable extent of monomer elution into 75% E/W with significantly higher amounts eluted from conventional composites. GRA and GND (conventional resin-composites) eluted TEGDMA in artificial saliva and GRA eluted TEGDMA in water.SignificanceThe hardness of CAD/CAM composite blocks was affected by different storage media, and they were not as stable as ceramic, with PICN exhibited superior hardness stability to all of the resin-composite blocks in all the storage media and was comparable to ceramic block. The hardness reduction percentage of the CAD/CAM composite blocks was influenced by the filler loading and resin-matrix composition.Minimal or no monomer elution from CAD/CAM blocks was detected.<br/

Bonding of different self-adhesive resins to high-strength composite resin block treated with surface conditioning

Purpose: This study aimed to evaluate the effects of chemical conditioning and self-adhesive resins (SARs)on the bonding of mechanically conditioned high-strength composite resin block (HSCRB). Methods: Eighteen sections of HSCRB (KZR-CAD HR 3 Gammatheta, Yamakin) were treated with alumina air abrasion and randomly divided into 3 groups according to the SARs for bonding: RelyX Unicem 2 (RXU), SA Luting Plus (SAL), and G-Cem ONE (GCO). The sections were further divided into 3 subgroups according to the chemical conditioning of the adherend surfaces: no conditioning (C), universal adhesive (UA), and a mixture of γ-MPTS and 10-MDP (MM). After the surface conditioning, the sections were cemented with the SARs. Each cemented section was cut into 40 beams. Half of the beams were thermocycled (4 °C/60 °C, 10,000 cycles). The micro-tensile bond strength (μTBS) values were measured using a universal testing machine.Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), contact angles, and surface roughness measurements were performed on the adherend surfaces of each subgroup.Results: RXU showed the highest μTBS values among the 3 SARs tested, while MM application exhibited the highest μTBS values among the 3 chemical conditioning methods tested. After thermocycling, the samples in the RXU/MM, RXU/UA, and GCO/MM groups showed no significant changes in the μTBS values,whereas the others showed a significant reduction. Conclusions: The bond strength of HSCRB was influenced by the chemical conditioning, SARs, and aging. γ-MPTS and 10-MDP application yielded higher μTBS values of mechanically treated HSCRB than the UA

Polymethacrylates.Material Selection For Medical Applications:Requirements For Several Kinds of Medical Applications

This chapter reviews several cases of methacrylate-based polymers used for medical applications. The main chemicals and fillers used for elaborating biomaterials are presented, together with the main synthesis reactions. Their properties are recalled and discussed using the well-established structure-properties relationships of polymer physicochemistry. Last, the main degradation mechanisms are recalled, together with their consequences on the engineering properties of polymethacrylates, in order to predict the long-term in vivo behavior of such complex materials