Stefano Cianetti

Hydrogen Sulphide Induces μ Opioid Receptor-Dependent Analgesia in a Rodent Model of Visceral Pain:

BackgroundHydrogen sulphide (H2S) is a gaseous neuro-mediator that exerts analgesic effects in rodent models of visceral pain by activating KATP channels. A body of evidence support the notion that KATP channels interact with endogenous opioids. Whether H2S-induced analgesia involves opioid receptors is unknown.MethodsThe perception of painful sensation induced by colorectal distension (CRD) in conscious rats was measured by assessing the abdominal withdrawal reflex. The contribution of opioid receptors to H2S-induced analgesia was investigated by administering rats with selective μ, κ and δ opioid receptor antagonists and antisenses. To investigate whether H2S causes μ opioid receptor (MOR) transactivation, the neuronal like cells SKNMCs were challenged with H2S in the presence of MOR agonist (DAMGO) or antagonist (CTAP). MOR activation and phosphorylation, its association to β arrestin and internalization were measured.ResultsH2S exerted a potent analgesic effects on CRD-induced pain. H2S-induced analgesia required the activation of the opioid system. By pharmacological and molecular analyses, a robust inhibition of H2S-induced analgesia was observed in response to central administration of CTAP and MOR antisense, while κ and δ receptors were less involved. H2S caused MOR transactivation and internalization in SKNMCs by a mechanism that required AKT phosphorylation. MOR transactivation was inhibited by LY294002, a PI3K inhibitor, and glibenclamide, a KATP channels blocker.ConclusionsThis study provides pharmacological and molecular evidence that antinociception exerted by H2S in a rodent model of visceral pain is modulated by the transactivation of MOR. This observation provides support for development of new pharmacological approaches to visceral pain.

Effect of fibre posts, bone losses and fibre content on the biomechanical behaviour of endodontically treated teeth: 3D-finite element analysis

The aim of this work was to evaluate the stress distribution inside endodontically treated teeth restored with different posts (glass fibre, carbon fibre and steel posts) under different loading conditions by using a 3D-finite element analysis. The effect of masticatory and impact forces on teeth with different degrees of bone loss was analysed. The model consists of: dentine, post, cement, gutta-percha, core and crown. Four simulations were conducted with two static forces (170N horizontal and 100N oblique) and two sections constrained: 1mm (alveolar bone position in a normal periodontium) and 6mm (middle of root) below the crown. Von Mises and the principal stresses were evaluated and analysed with a 3-way ANOVA and Tukey test (α=0.05) and the effect of fibre percentage analysed. Significant differences were found among the stress values for all conditions (p<0.05). Impact load was always responsible for the most critical situation especially when the bone loss was more evident. The system with steel posts showed the highest principal stresses at the post-cement interface with horizontal load and top constraints (compressive stress of 121MPa and tensile stress of 115MPa). The use of glass posts provides a more homogeneous behaviour of the system with lower stresses. Higher fibre percentages gave higher stress in the posts. Moreover, larger bone losses are responsible for important increase in stress. Thus, this work demonstrated that periodontal disease has an important role in the success of tooth restoration after endodontic therapy, influencing the choice of post material and depth.

Sonic and ultrasonic oscillating devices for the management of pain and dental fear in children or adolescents that require caries removal: a systematic review

Objectives To evaluate the effectiveness and degree of acceptance by children and adolescents of the use of oscillating tips compared with rotating drills. Design Systematic review. Data sources PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library and Web of Science (October 2017). Eligibility criteria Controlled randomised or non-randomised trials that evaluated sonic and ultrasonic oscillating devices versus rotating drill. Data extraction Eligible studies were selected and data extracted independently by two reviewers. Risk of bias was assessed using the Cochrane Method. Results Two controlled clinical trials comprising 123 children aged 2–12 years old were identified. Both trials were at high risk of selection bias and unclear risk of detection bias. In one trial, pain due to the use of oscillating drill resulted lower than employing rotating drill (Verbal Hochman Scale: RR 0.64 (95% CI 0.41 to 1.00); Visual Facial Expression Scale: RR 0.64 (95% CI 0.44 to 0.94)). In another study, compared with traditional drill ultrasonic tip was associated with a lower level of patient’s discomfort (RR 0.40 (95% CI 0.20 to 0.79)) but not with dental anxiety (RR 1.29 (95% CI 0.97 to 1.71)). The effectiveness of the removal of caries as well as fillings durability were only considered in one study, but no statistically significant differences were found between the two interventions. Conclusions The evidence based on two low-quality studies was insufficient to conclude that the use of oscillating tips for the management of pain and dental fear in children or adolescents compared with rotating drills was more effective.

Evidence of pharmacological and non-pharmacological interventions for the management of dental fear in paediatric dentistry: a systematic review protocol

Introduction Several techniques have been proposed to manage dental fear/dental anxiety (DFA) in children and adolescents undergoing dental procedures. To our knowledge, no widely available compendium of therapies to manage DFA exists. We propose a study protocol to assess the evidence regarding pharmacological and non-pharmacological interventions to relieve dental anxiety in children and adolescents. Methods and analysis In our systematic review, we will include randomised trials, controlled clinical rials and systematic reviews (SRs) of trials that investigated the effects of pharmacological and non-pharmacological interventions to decrease dental anxiety in children and adolescents. We will search the Cochrane Database of Systematic Reviews, the Cochrane Database of Abstracts of Reviews of Effects=, the Cochrane Central Register of Controlled Trials, PubMed, PsycINFO, Cumulative Index to Nursing and Allied Health Literature and the Web of Science for relevant studies. Pairs of review authors will independently review titles, abstracts and full texts identified by the specific literature search and extract data using a standardised data extraction form. For each study, information will be extracted on the study report (eg, author, year of publication), the study design (eg, the methodology and, for SRs, the types and number of studies included), the population characteristics, the intervention(s), the outcome measures and the results. The quality of SRs will be assessed using the A Measurement Tool to Assess Reviews instrument, while the quality of the retrieved trials will be evaluated using the Cochrane Handbook for Systematic Reviews of Interventions criteria. Ethics and dissemination Approval from an ethics committee is not required, as no participants will be included. Results will be disseminated through a peer-reviewed publications and conference presentations.

Valutazione della capacità di taglio di tre punte diamantate a diversa granulometria nella preparazione protesica di elementi dentari

Riassunto Obiettivi Lo studio si propone un duplice obiettivo: valutare la granulometria piu idonea nella rimozione di tessuto dentale da parte di tre punte diamantate utilizzate per preparazioni protesiche e verificare la relazione tra la capacita di taglio delle tre punte e la densita dei grani di diamante disposti sulla testa lavorante. Materiali e Metodi Sono state utilizzate tre punte diamantate da preparazione protesica con tre diverse granulometrie: grana media 100xa0μm (Komet 878), grana grossa 120xa0μm (Komet 6878) e grana supergrossa 180xa0μm (Komet 5878). Dette punte sono state utilizzate su un manipolo moltiplicatore di giri (anello rosso) azionato da un braccio meccanico, per standardizzare le condizioni di taglio. Le prove di taglio sono state condotte su prismetti di macor (CS Ltd, Newport, UK), un materiale sintetico vetroceramico con caratteristiche di durezza ed elasticita confrontabili a quelle del dente naturale. Le tre punte abrasive, inoltre, sono state analizzate al microscopio ottico a dieci ingrandimenti (10X) a luce polarizzata e processate mediante un software di analisi di immagini (Scientific Image-Analysis, ImageJ, National Institutes of Health, USA), prima del loro impiego, per valutare la densita di disposizione dei cristalli nelle tre differenti granulometrie. Risultati La punta abrasiva a media granulometria (100xa0μm) ha mostrato la migliore capacita di taglio, pari a 0,217xa0mm/s (millimetri di affondamento dello strumento rotante nei prismetti di macor nell’unita di tempo). La grana media e stata seguita, in efficacia di taglio, dalla punta abrasiva a grana grossa (120xa0μm) con un valore pari a 0,181xa0mm/s e dalla grana supergrossa (180xa0μm) con un valore pari a 0,145xa0mm/s. In ciascuna punta abrasiva la capacita di taglio e diminuita con il numero dei tagli eseguiti. La densita di disposizione dei cristalli nelle tre punte abrasive, analizzata prima delle prove di taglio, e risultata sostanzialmente equivalente: nella media granulometria (100xa0μm) i grani occupavano una superficie complessiva dell’85,1%, nella grossa granulometria (120xa0μm) un’area dell’83,4% e nella super-grossa (180xa0μm) un’area dell’85,3%. Discussione L’ottima capacita di taglio mostrata dalla punta a media granulometria (100xa0μm) costituisce una condizione vantaggiosa nella preparazione del dente. La media granulometria, infatti, produce una rugosita iniziale delle superfici del moncone dentario contenuta, inferiore a quella ottenibile con le altre due granulometrie piu voluminose (120xa0μm e 180xa0μm), rendendo piu facili ed efficaci le successive operazioni di rifinitura dentinale. La densita della disposizione dei cristalli di diamante, essendo sostanzialmente analoga nelle tre granulometrie, non puo essere causa della diversa efficacia di taglio mostrata dalle tre punte testate. Si suppone, pertanto, che la differente attitudine al taglio mostrata dalle tre diverse granulometrie dipenda dalle caratteristiche dei singoli grani di diamante anziche dalla loro disposizione. Conclusioni L’esito del nostro lavoro costituisce una nota di dissonanza rispetto a quanto emerso dall’analisi della letteratura relativa agli studi assimilabili al presente per campo di interesse e metodologia sperimentale. Dalla letteratura, infatti, in alcuni lavori si evince una mancata relazione tra capacita di taglio e dimensione dei grani di diamante; in altri studi una ridotta attitudine abrasiva delle punte diamantate a grana media rispetto alle granulometrie maggiori, in particolare quando l’impiego si prolunga nel tempo. La mancata univocita di risultati relativa agli studi su questa tecnica dovrebbe costituire uno stimolo per nuovi studi preferibilmente di ordine clinico piuttosto che di laboratorio.

Biological, thermal and mechanical characterization of modified glass ionomer cements: The role of nanohydroxyapatite, ciprofloxacin and zinc l-carnosine

The study evaluated the effects of 4u202fwt% nanohydroxyapatite (HA), 6u202fwt% zinc l-carnosine (MDA) and 1.5u202fwt% Ciprofloxacin (AB) on the mechanical, thermal and biological properties of glass ionomer cements (GIC). Filler and additive concentrations were selected after a previous study had tested single components and different percentages. Specimens included five silicon molds of each GIC cement for all tests. They were stored at room temperature for 24u202fh from specimen collection to analysis. Mechanical tests, calorimetric analysis, morphological investigation, antibacterial and cell viability assays were conducted. One-way analysis of variance (ANOVA) was used for data analysis with significance set at pu202f<u202f0.05. Adding HA, MDA and AB to GICs modified their thermal, mechanical and microbiological properties. Polymerization increased. A slight decrease in the compressive strength of modified GICs was observed in dry condition (pu202f<u202f0.05). Cement extracts affected cell viability in relation to extract dilution. Mechanical behavior improved in modified glass ionomer cements, especially with the powder formulated antibiotic. Overall cytotoxicity was reduced. Therefore adding nanohydroxyapatite, antibiotic and a mucosal defensive agent to conventional glass ionomer cement in special need patients could improve the clinical, preventive and therapeutic performance of the cements, without altering their mechanical properties.

I nuovi anticoagulanti orali e la loro gestione nella pratica clinica odontoiatrica

Riassunto Obiettivi Scopo dello studio e valutare le implicazioni dei nuovi anticoagulanti orali (Novel Oral Anticoagulants, NOA) nelle terapie odontoiatriche, alla luce della recente letteratura. Materiali e metodi E stata eseguita una valutazione comparativa degli studi condotti negli ultimi cinque anni per confrontare gli effetti dei NOA rispetto agli anticoagulanti tradizionali nelle procedure odontoiatriche. Risultati Rapidita d’azione, minori interazioni farmacologiche ed esigenza di monitoraggio non continuo renderebbero i NOA vantaggiosi rispetto agli anticoagulanti tradizionali. Ulteriori indagini sono tuttavia necessarie. Conclusioni La letteratura conferma la possibilita di mantenere la terapia con i NOA durante le principali procedure odontoiatriche. Importante e definire specifici criteri clinici.