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Objectives The aim of this study was to investigate, by the means of microtensile bond strength (μTBS) test, gelatin and in situ zymography, the influence of 0.2% CHX contained within a commercially available adhesive on long-term bond strength and endogenous enzymatic activity. Methods Non-carious teeth were subjected to μTBS test (N = 15 for each group) and stressed until failure. μTBS was evaluated immediately and after 12-month storage in artificial saliva at 37 °C. Dentin powder was obtained from additional teeth (N = 7) for gelatin zymography, while for in situ zymography, 3 teeth for each group were selected. Gelatin and in situ zymography were performed in dentin powder and slices of dentin, respectively, to assess the ability of 0.2% CHX blended within the adhesive to inhibit endogenous enzymatic activity. Results μTBS bond strength was higher in the CHX-containing groups, immediately as well as after aging. The bond strength significantly decreased after 12-month aging. The activation of endogenous MMPs was found to be related to the presence of CHX within the adhesive system and the bonding strategy employed. Conclusions Under this perspective 0.2% CHX blended within Peak Universal adhesive monomer seems to increase immediate bond strength, to preserve bond strength over time and to efficiently inhibit endogenous enzymatic activity in dentin. Hence, blending the CHX in low concentrations within the adhesive could be recommended as a feasible technique in every-day clinical practice. Clinical significance Using CHX-containing adhesives could be recommended due to several benefits: it seems to increase the longevity of the hybrid layer; the inhibitor appears to be efficiently delivered to the dentinal substrate and to inhibit endogenous enzymatic activity, without prolonging chair time.

Objectives: The present in vitro study evaluated the effect of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), a cross-linking agent used as an additional therapeutic primer for luting fiber posts to radicular dentine to prevent hybrid layer degradation. Methods: Root canal treatment was performed on 80 extracted single-rooted human teeth. A 10-mm post space was prepared and pecimens were randomly assigned to four groups (n=20) according to the bonding system: 1) All Bond 3 (Bisco); 2) All Bond 3 + 0.3M EDC; 3) Prime&Bond XP (Dentsply Sirona); 4) Prime&Bond XP + 0.3M EDC. In groups 2 and 4, EDC was applied on phosphoric acid-etched dentine for 1 min. Fiber posts (RelyX Fiber Post, 3M ESPE) were luted with a dual-cured resin cement (Core-X flow, Dentsply Sirona). Slices were prepared for micro push-out test and interfacial nanoleakage evaluation of the coronal and apical region of the canal space after 24 h and 1 year storage in artificial saliva. In-situ zymography was performed to investigate endogenous matrix metalloproteinase activities within the hybrid layer. Results were statistically analysed with three-way ANOVA test or Chi Square test. Statistical significance was set at α=0.05. Results: No significant influence was identified between the two adhesives. The use of EDC significantly improved fiber post bond strength at 1 year but not at 24 h. Application of 0.3 M EDC prior to bonding significantly reduced gelatinolytic activities within the radicular hybrid layers. Conclusions: Carbodiimide was effective in preserving fibre post bond strength over time, through reducing the activities of intra-radicular endogenous proteases. Clinical Significance: Inhibition of matrix metalloproteinases using EDC over radicular dentin could play an important role in bond strength preservation. However, the clinical relevance of these findings needs to be proven.

Objectives: Matrix metalloproteinases (MMPs) are dentinal endogenous enzymes claimed to have a vital role in dentin organic matrix breakdown. The aim of the study was to investigate presence, localization and distribution of MMP-7 in sound human dentin. Methods: Dentin was powdered, demineralized and dissolved in isoelectric focusing buffer. Resolved proteins were transferred to nitrocellulose membranes for western blotting (WB) analyses. For the zymographic analysis, aliquots of dentin protein were electrophoresed in 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis containing fluorescently labeled gelatin. Further, the concentrations of dentinal MMPs were measured using Fluorescent Microsphere Immunoassay with a human MMP-MAP multiplex kit. Pre- and post-embedding immunolabeling technique was used to investigate the localization and distribution of MMP-7 in dentin. Dentin was cryo-fractured, the fragments partially decalcified and labeled with a primary monoclonal anti-MMP-7 and a secondary antibody conjugated with gold nanoparticles. MMP-7 labelings were identified in the demineralized dentin matrix as highly electron-dense dispersed gold particles. Results: WB and zymographic analysis of extracted dentin proteins showed presence of MMP-7 (similar to 20-28 KDa). Further, MMP-7 was found in the supernatants of the incubated dentin beams using Fluorescent Microsphere Immunoassay. FEI-SEM and TEM analyses established MMP-7 as an intrinsic constituent of the human dentin organic matrix. Conclusion: This study demonstrated that MMP-7 is an endogenous component of the human dentin fibrillar network. Clinical significance: It is pivotal to understand the underlying processes behind dentin matrix remodeling and degradation in order to develop the most optimal clinical protocols and ensure the longevity of dental restorations.

Made available in DSpace on 2018-12-11T17:16:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Objectives The objective of the present study was to investigate the long-term effect of 0.01% acrolein (ACR) aqueous solution, employed as an additional primer, on the mechanical durability and enzymatic activity of resin-dentine interfaces created with a simplified etch-and-rinse adhesive. Methods Dentine surfaces were etched with 35% phosphoric acid for 15 s, rinsed and blot-dried. Specimens were then assigned to: Group 1: dentine pre-treated with 0.01% ACR aqueous solution for 1 min and bonded with Adper Scotchbond 1 XT (SB1XT), a 2-step etch-and-rinse adhesive; Group 2: SB1XT was applied on untreated acid-etched dentine (control). Resin composite build-ups were made using Filtek Z250. Microtensile bond strength was tested by stressing sectioned specimens to failure immediately or after 1 year of storage in artificial saliva at 37 °C. Zymography and in-situ zymography assays were performed for examining dentine matrix metalloproteinase (MMP) activities. Results The use of 0.01% ACR as conditioning primer appeared to have contributed better to preservation of bond strength over time without affecting immediate bond strength. Zymography and in-situ zymography showed reduction in MMP activities after the application of ACR. Conclusion Dentine collagen cross-linking produced by an ACR-based primer increases the longevity of resin-dentine bonds by reinforcement of the adhesive interface and reduction of dentine MMP activities. Further studies are required to evaluate the potential in vivo and in vivo cytotoxicity of ACR. Clinical significance The acrolein-based primer is a potentially useful clinical bonding tool because it demonstrates good collagen cross-linking ability within a clinically-acceptable working time. Although a low ACR concentration was employed in the present study, the cytotoxicity of ACR should be tested prior to clinical use. Department of Biomedical and Neuromotor Sciences DIBINEM University of Bologna - Alma Mater Studiorum School of Dentistry Faculty of Medicine University of Novi Sad Department of Restorative Dentistry School of Dentistry University of São Paulo Private Practice Department of Pediatric Dentistry and Orthodontics Araraquara School of Dentistry UNESP – University of Estadual Paulista The Dental College of Georgia Augusta University Department of Pediatric Dentistry and Orthodontics Araraquara School of Dentistry UNESP – University of Estadual Paulista

Objectives To evaluate the influence of surface treatments of different resin-based composites (RBCs) on S. mutans biofilm formation. Methods 4 RBCs (microhybrid, nanohybrid, nanofilled, bulk-filled) and 6 finishing-polishing (F/P) procedures (open-air light-curing, light-curing against Mylar strip, aluminum oxide discs, one-step rubber point, diamond bur, multi-blade carbide bur) were evaluated. Surface roughness (SR) (n = 5/group), gloss (n = 5/group), scanning electron microscopy morphological analysis (SEM), energy-dispersive X-ray spectrometry (EDS) (n = 3/group), and S. mutans biofilm formation (n = 16/group) were assessed. EDS analysis was repeated after the biofilm assay. A morphological evaluation of S. mutans biofilm was also performed using confocal laser-scanning microscopy (CLSM) (n = 2/group). The data were analyzed using Wilcoxon (SR, gloss) and two-way ANOVA with Tukey as post-hoc tests (EDS, biofilm formation). Results F/P procedures as well as RBCs significantly influenced SR and gloss. While F/P procedures did not significantly influence S. mutans biofilm formation, a significant influence of RBCs on the same parameter was found. Different RBCs showed different surface elemental composition. Both F/P procedures and S. mutans biofilm formation significantly modified this parameter. Conclusions The tested F/P procedures significantly influenced RBCs surface properties but did not significantly affect S. mutans biofilm formation. The significant influence of the different RBCs tested on S. mutans biofilm formation suggests that material characteristics and composition play a greater role than SR. Clinical significance F/P procedures of RBCs may unexpectedly play a minor role compared to that of the restoration material itself in bacterial colonization.

Made available in DSpace on 2018-12-11T17:19:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-01 National Natural Science Foundation of China Objectives: The water-associated attributes of resin-dentin interfaces created by contemporary adhesives are important determinants of bond integrity and stability. In the present work, these attributes were estimated from the perspectives of causality, to examine the behavior of the first and most-recently launched versions of universal adhesives when applied in either the etch-and-rinse mode or the self-etch mode. Methods: The immediate cause of interfacial permeability and the time-dependent cause of water sorption were investigated in conjunction with the intermediate effect of interface degradation and the more long-term effect of loss of mechanical strength, before and after thermomechanical cycling. The results were compared with control etch-and-rinse and self-etch adhesives. Results: Although the introduction of this new class of universal adhesives has brought forth significant changes to the dental adhesion arena, including more application options, reduced bonding armamentarium and increased user friendliness, the water-associated attributes that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large, when compared with benchmarks established by former classes of adhesives. Conclusion: It appears that the current trend of adhesive development has brought forth significant changes but lacks the vigor that demarcates progress and technological sublimity. Clinical significance: The advent of the user friendly universal adhesives has brought forth significant changes to the dental adhesion arena. However, the elements that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large. Department of Restorative Dentistry Institute of Science and Technology São Paulo State University UNESP São Jose dos Campos Department of Operative Dentistry and Endodontics Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology Sun Yat-sen University State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology School of Stomatology The Fourth Military Medical University Department of Endodontics The Dental College of Georgia Augusta University Department of Biomedical and Neuromotor Sciences DIBINEM University of Bologna – Alma Mater Studiorum The Third Affiliated Hospital of Xinxiang Medical University Department of Restorative Dentistry Institute of Science and Technology São Paulo State University UNESP São Jose dos Campos National Natural Science Foundation of China: 81720108011 National Natural Science Foundation of China: 81722015

Objectives To evaluate retrospectively the longevity of endodontically treated teeth restored with direct resin composite without cusp coverage, with or without the insertion of fibre posts. The null hypothesis was that direct restorations with fibre posts perform better than those without fibre posts. Methods Patients recruited for this study were treated in the Department of Cariology and Operative Dentistry, University of Turin, between 2008 and 2011. In total, 247 patients with 376 root treated posterior teeth, restored with direct resin composite, were recalled for a control visit. Only second-class cavities were considered. Two groups were defined based on the absence (Group A) or presence (Group B) of fibre post. Failures and complications, such as periodontal failure, endodontic failure, tooth extraction, root fracture, post fracture, post debonding, replacement of restoration, crown displacement, and coronal-tooth fracture, were noted. Functional restoration quality was evaluated following the modified USPHS criteria. Data were evaluated statistically with ANOVA. Results Group A consisted of 128 patients with 178 restorations (88 premolars, 90 molars) with a median follow-up of 34.44 months. Group B consisted of 119 patients with 198 teeth (92 premolars, 106 molars) with a median follow-up of 35.37 months. Direct restorations with fibre posts were statistically significantly more functional (95.12% success) than those without fibre posts (80% success) because of less marginal discolouration, better marginal integrity, and higher restoration integrity. Conclusions The null hypothesis was accepted because direct post-endodontic restorations with fibre posts performed better than restorations without posts after 3 years of masticatory function. Clinical significance An evaluation of the longevity of post endodontic direct restoration would seem to enhance the fiber post insertion within a composite restoration to reduce clinical failures.

Objectives The study evaluated the fracture resistance and fracture patterns of endodontically treated mandibular first molars restored with glass-fiber-reinforced direct composite restorations. Methods In total, 60 extracted intact first molars were treated endodontically; a mesio-occluso-distal (MOD) cavity was prepared and specimens were then divided into six groups: sound teeth (G1), no restoration (G2), direct composite restoration (G3), fiber-post-supported direct composite restoration (G4), direct composite reinforced with horizontal mesio-distal glass-fibers (G5), and buccal-palatal glass-fibers (G6). Specimens were subjected to 5000 thermocycles and 20,000 cycles of 45° oblique loading force at 1.3 Hz and 50 N; they were then loaded until fracture. The maximum fracture loads were recorded in Newtons (N) and data were analyzed with one-way ANOVA and post-hoc Tukey tests (p

Objectives Tuberculosis transmission among healthcare workers (HCWs) and patients is due to the level of Mycobacterium tuberculosis (MT) circulation in the community and in the healthcare settings where HCWs are active. In contrast, most papers about dentistry report that dental HCWs (DHCWs) and patients are at relatively high risk, mainly based on tuberculosis case series that occurred in the 80’s–90’s. This meta -narrative review was designed to evaluate the tuberculosis risk in dentistry accounting for the historical-geographical contexts. Data All available studies reporting data on MT infection (active/latent tuberculosis, tuberculin skin test) among patients and DHCWs. Sources PubMed, Scopus, GOOGLE Scholar. Keywords MT/tuberculosis and dentistry/dentist/dental/dent*. Results 238 of the 351 titles were excluded because did not concern dental healthcare providing, 94 papers were excluded because they did not provide original data. Thirteen studies on occupational risk, nine on transmission to patients remained. Some, often non-confirmed, cases of MT infection among patients were reported in specific historical-geographical contexts where MT was endemic. The risk of active pulmonary tuberculosis transmission from infected DHCWs to patients is minimal today, provided that the basic infection control guidelines are applied. The development of active tuberculosis among DHCWs is occasional and is associable to MT circulation rather than dental healthcare providing. Clinical significance Tuberculosis transmission in dental healthcare settings was due to the lack of basic infection control measures, while the risk is acceptable (i.e., similar to the general population) nowadays. Therefore, tuberculosis transmission can be safely prevented wearing gloves and surgical mask and providing regular air changes in the operative and non-operative dental healthcare settings. Precautionary Principle-based measures are implementable when patients with active pulmonary tuberculosis are routinely treated.