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A photocrosslinkable gelatin methacryloyl (GelMA) hydrogel has been widely examined in regenerative engineering because of its good cell–tissue affinity and degradability in the presence of matrix metalloproteinases. A halloysite aluminosilicate nanotube (HNT) is a known reservoir for the loading and sustained delivery of therapeutics. Here, we formulate injectable chlorhexidine (CHX)-loaded nanotube-modified GelMA hydrogel that is cytocompatible and biodegradable and provides sustained release of CHX for infection ablation while displaying good biocompatibility. The effects of HNTs and CHX on hydrogel degradability and mechanical properties, as well as on the kinetics of CHX release, and on the antimicrobial efficacy against oral pathogens were systematically assessed. Cytocompatibility in stem cells from human exfoliated deciduous teeth and inflammatory response in vivo using a subcutaneous rat model were determined. Our hydrogel system, that is, (CHX)-loaded nanotube-modified GelMA showed minimum localized inflammatory responses, supporting its ability for drug delivery applications. Moreover, we showed that the incorporation of CHX-loaded nanotubes reduces the mechanical properties, increases the swelling ratio, and diminishes the degradation rate of the hydrogels. Importantly, the presence of CHX-loaded nanotubes inhibits bacterial growth with minimal cell toxicity. Our findings provide a new strategy to modify GelMA hydrogel with chlorhexidine-loaded nanotubes for clinical use as an injectable drug delivery strategy for dental infection ablation.

The aim of this study was to evaluate the solubility of three types of root canal sealers in three organic solvents used in endodontics. The solubility of calcium-hydroxide-based (Sealer 26), silicon-polydimethylsiloxane-based (RoekoSeal), and zinc-oxide-eugenol based (Endofill and Intrafill) sealers was assessed in eucalyptol, xylol, orange oil, and distilled water. Eighty samples of each filling material were prepared according to the manufacturers' instructions and then divided into four groups for immersion in solvent for 2 or 10 min. The means of sealer dissolution in solvents were obtained by the difference between the original preimmersion weight and the postimmersion weight in a digital analytical scale. Data were statistically analyzed with the Student's t test, and multiple comparisons were performed with Student-Newman-Keuls. Xylol and orange oil showed similar effects, with significant solubilization (P<0.05) of the tested cements. Endofill and Sealer 26 did not show any significant difference in solubilization at the two immersion times, whereas RoekoSeal and Intrafill showed a more pronounced solubility at 10 min. The lowest levels of solubilization occurred in RoekoSeal, Sealer 26, Endofill, and Intrafill. It is concluded that xylol and orange oil presented similar solvent effects with a significant solubility of the tested cements.

The aim of this study was to evaluate the solubility of gutta-percha in four organic solvents used in endodontics. The solubility of gutta-percha (Dentsply) was assessed in xylol, orange oil, eucalyptol, chloroform and distilled water. A hundred and fifty samples of gutta-percha were prepared using a standardized stainless steel mould and divided into five groups for immersion in the different solvents tested and in distilled water (control group) for 2, 5 and 10 minutes. The means of gutta-percha dissolution in the solvents were obtained by the difference between the pre-immersion original weight and the post-immersion weight in a digital analytical scale (Gehaka-AG2000). Data were statistically analyzed by Analysis of Variance (ANOVA) and multiple comparisons with Scheffes test (p<0.05). The best solvency capacity was obtained with xylol. Chloroform, orange oil and eucalyptol presented similar results, and distilled water did not promote alterations in the gutta-percha.

This retrospective study evaluated the clinical performance and the reasons for failure of anterior and posterior composite restorations placed by undergraduate dental students over a 3-year period. All cavities were restored using Prime & Bond 2.1 and TPH (Dentsply), according to the manufacturer's indications. One hundred and two patients who had received composite restorations by third and forth year undergraduate students were recalled and examined to analyze the quality of the restorations. The restorations were evaluated using the modified USPHS system. Two hundred and fifty-six composite restorations, 170 in anterior teeth and 86 in posterior teeth, were evaluated. Eighty-five percent of the restorations were considered satisfactory after 3 years. Class II and class IV restorations presented the highest prevalence of failure. Loss of the restoration and deficient marginal adaptation were the main causes of failure. No restoration failed due to secondary caries. Most restorations placed by dental students were considered satisfactory after long-term evaluation. Failure was more prevalent in larger restorations and was not associated with secondary caries.

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The aim of this study was to review the effectiveness of methods used for teaching dental anatomy carving to dental students in operative dentistry as evaluated in published studies. This systematic review is described in accordance with the PRISMA statement. Two independent reviewers performed a systematic literature search of research published from January 1945 until May 2014. Seven databases were screened: MedLine (PubMed), Lilacs, IBECS, Web of Science, Scopus, SciELO, and The Cochrane Library. After removing duplicates, only studies using dental carving to assess the practical knowledge of anatomy were selected. The tabulated data were organized by title of article, names of authors, number of students assessed, assessment method, material used, groups tested, main results, and conclusions. The methodology quality was assessed according to the Cochrane Handbook for Systematic Reviews of Interventions. Initially, 2,258 studies were identiied in all databases. Five articles met the eligibility criteria and were included in this review. According to these studies, the geometric method, teaching step-bystep along with the teacher, and adjuvant methods such as the use of tutors and teaching through digital media with DVDs proved to be effective in improving learning. There is no standard technique that is widely accepted for the teaching of dental carving, nor is there an appropriately validated method of evaluation to verify whether the teaching methods used are effective for the acquisition of skills and expertise in dental anatomy by students.

ObjectivesThe aim of this study was to assess technical preferences of general dental practitioners when restoring anterior composite restorations. How the level of clinical experience or post-graduate training infuenced their options was also tested. Material and MethodsA cross-sectional study was performed using a questionnaire with general dental practitioners (GDPs) (n=276) in Southern Brazil. Information regarding post graduation training (specialization, master's or PhD degree) and linical experience (years since completing graduation) were gathered. The options regarding anterior composite restorations (type of composite, adhesive system, light curing unit, polishing procedures and rubber dam use) were collected. Data were submitted to descriptive analysis and associations were tested. ResultsResponse rate was 68% (187). GDPs selected microhybrid composite (52%) and 2-step total etch adhesive system (77%). LED was the preferred method of activation for 72.8%. Immediate polishing was preferred by 75%, using a combination of techniques. Most of the respondents (74.3%) did not use rubber dam. More experienced clinicians used more halogen lights (p<0.022), performed more light monitoring (p<0.001) and were resistant to use rubber dam (p<0.012). Dentists with post-graduation training used 3-etch-and-rinse system more frequently (p<0.04), usually monitored light intensity (p<0.014) and placed rubber dam more frequently (p<0.044). ConclusionsHybrid composite, simplifed adhesives, LED units and immediate polishing were preferred by Southern Brazilian dentists for anterior composite restorations. Few dentists used rubber dam to perform composite restorations in anterior teeth. Clinical experience and post-graduation training infuenced the dentists' choices.