The relationship between mood disorders, personality disorder and suicidality in adolescence: does general personality disturbance play a significant role in predicting suicidal behavior?

INTRODUCTION: Current research points to the importance personality pathology and Major Depression e as relevant psycopathological risk factors for understanding suicidal risk in adolescence. Literature has mainly focused on the role of BPD, however current orientations in personality pathological functioning suggest that BPD may be the representative of a general personality disturbance, a factor of vulnerability underlying diverse psychopathological variants and aspects of maladaptive functioning. However, recent studies seem to have neglected the contributions that other specific personality disorders and personality pathology as a general factor of vulnerability for suicidality; and only marginally investigated the interaction of personality disorder (PD) as an overall diagnosis and individual PDs and major depression (MDD). In this paper, the independent and cumulative effects of MDD and DSM-IV PDs on suicidal risk are investigated in a sample of adolescents observed in a longitudinal window of observation ranging from three months preceding the assessment to a six-month follow up period of clinical monitoring. METHODS: A sample of 118 adolescents (mean age = 15.48 ± 1.14) referred for assessment and treatment on account of suicidal ideation or behavior were administered the CSSRS, SCID II, Kiddie-SADS at admission at inpatient and outpatient Units. All subjects included in the study had reported suicidal ideation or suicide attempts at the C-SSRS; The CSSRS was applied again to all patients who reported further suicidal episodes during the six-months follow-up period of clinical monitoring. Dimensional diagnoses of PDs was obtained by summing the number of criteria met by each subject at SCID-%-PD 5, In order, to test the significance of the associations between the variables chosen as predictors (categorical and dimensional PDs and MD diagnosis), and the suicidal outcomes variables suicide attempts, number of suicide attempts and potential lethality of suicide attempt, non-parametric bivariate correlations, logistic regression models and mixed-effects Poisson regression were performed PD. RESULTS: The categorical and dimensional diagnosis of PD showed to be a significant risk factors for suicide attempt and their recurrence, independently of BPD, that anyway was confirmed to be a specific significant risk factor for suicidal behaviors. Furthermore, PD assessed at a categorical and dimensional level and Major Depression exert an influence on suicidal behaviors and their lethality both as independent and cumulative risk factors. LIMITATIONS: Besides incorporating dimensional thinking into our approach to assessing psychopathology, our study still relied on traditionally defined assessment of PD. Future studies should include AMPD-defined personality pathology in adolescence to truly represent dimensional thinking. CONCLUSION: These results point to the importance of early identification of the level of severity of personality pathology at large and its co-occurrence with Major Depression for the management of suicidal risk in adolescence.

Restorative Materials Exposed to Acid Challenge: Influence of Temperature on In Vitro Weight Loss.

Consumption of acidic beverages and foods could provoke erosive damage, both for teeth and for restorative materials. Temperatures of consumption could influence the erosive effects of these products. The aim of this in vitro study is to assess the influence of an acidic challenge on the weight loss of different restorative materials. Resin composites and glass-ionomer cements (GIC) were tested. The medium of storage was Coca-Cola (Coca-Cola, Coca-Cola Company, Milano, Italy) at two different temperatures, 4 and 37 °C, respectively for Group A and Group B. For each group, nine specimens were prepared for each material tested. After 7 days, weight was assessed for each sample, and the percentage weight loss was calculated. For all the resin composites (Groups 1−13), no significant weight losses were noticed. (<1%). Conversely, GICs (Groups 14 and 15) showed significant weight loss during the acidic challenge, which was reduced in the case of these materials that included a protective layer applied above. Significant differences were registered with intra-group analysis; weight loss for specimens immersed in Coca Cola at 37 °C was significantly higher for almost all materials tested when compared to specimens exposed to a cooler medium. In conclusion, all the resin composites showed reliable behaviour when exposed to acidic erosion, whereas glass-ionomer cements generally tended to solubilize.

Two-year follow-up and changes in reflective functioning in specialist and nonspecialist treatment models for personality disorder.

There is a growing body of studies linking impairments in mentalizing or reflective functioning (RF) with childhood adversity, the development of personality disorder (PD), and psychiatric morbidity. Fewer studies have investigated the purported role of changes in RF in relation to clinical outcome in treatments focusing on this capacity. Moreover, it is as yet unclear whether specialist and nonspecialist treatment models are equally effective in bringing about change in RF in conjunction with symptomatic improvement. This study aimed to investigate the association between changes in RF in 3 samples of individuals with PD treated in 2 specialist psychosocial programs (a mixed residential and community-based step-down program [RT-CBP] and a residential-only psychotherapy treatment program [RT]) and in an outpatient general psychiatric service over a 2-year period after intake into treatment. RF was assessed using the Reflective Functioning Scale scored on the Adult Attachment Interview, and clinical outcome was assessed in terms of psychiatric distress, social adjustment, and global functioning. Changes in RF were most marked in RT-CBP compared with RT and general psychiatric service. Changes in RF explained differences between treatment models for social and global adjustment outcomes, but not for disparities in psychiatric distress. A medium-intensity treatment approach to PD such as RT-CBP was more effective in improving RF and provided a balance between psychotherapy input and efforts at social integration, by bringing patients into closer contact with their social world. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Influence of Different Surface Pretreatments on Shear Bond Strength of an Adhesive Resin Cement to Various Zirconia Ceramics.

The aim of this in vitro study was to assess the influence of surface pretreatment on shear bond strength (SBS) of an adhesive resin cement (G-CEM Link Force TM, GC Corporation, Tokyo, Japan) to three different yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics: (1) Copran Zirconia Monolith HT, COP; (2) Katana ML Zirconia, KAT; and (3) Metoxit Z-CAD HTL Zirconia, MET. In total, 45 cylinders (5 mm in diameter, 1 mm height) for each type of zirconia ceramic were prepared used a computer-aided design and computer-aided manufacturing (CAD/CAM) machine (software CEREC 4.2). Each type of zirconia was subdivided into three groups and each group received a different surface pretreatment; 15 samples were not conditioned as control (groups COP 1, KAT 1, MET 1), 15 samples were air-borne particle abraded with aluminum dioxide particles of 50-µm size at 0.3 MPa for 20 s (groups COP 2, KAT 2, MET 2), and 15 samples were hot-etched with a solution of hydrochloric acid and ferric chloride (groups COP 3, KAT 3, MET 3). After specimen fabrication, the adhesive cement-ceramic interface was analyzed using an SBS test. Subsequently, the adhesive remnant index (ARI) was measured. Data were submitted to statistical analysis. Air-borne particle abraded specimens showed the highest SBS values for COP and KAT groups. For MET, no significant difference was reported between air-borne particle abraded specimens and untreated controls. The lowest values were detected for acid-etched groups. A higher frequency of ARI = "1" and ARI = "2" was reported in control and air-borne particle abraded groups, whereas ARI = "3" was detected in hot-etched groups. No correlation was found between ARI score and shear bond strength. Air-borne particle abrasion is considered the best treatment for Zirconia Copran and Zirconia Katana ML, if it is followed by using dual-curing resin cement.

Clinical Associations Between Severity of Impulsivity, Psychiatric Morbidity, Dysfunctional Defences and Personality Disorder: A Comparative Study With Axis-I Disorders.

OBJECTIVE: Psychiatric morbidity, impulsive behaviour and use of dysfunctional and maladaptive defences are core features of personality disorder (PD). This study aims to evaluate the significance of the strength of the association between these three core dimensions and PD. METHOD: Using a cross-sectional design, a sample of co-morbid Axis-I & -II disorders, and a sample of Axis-I disorders with no co-morbid PD were recruited at three general psychiatric mental health resource centres and then compared.PD as dependent variable was analysed both as a categorical and as a dimensional entity using the Structured Clinical Interview for DSM-IV. The Symptoms Checklist 90-R general severity index (GSI), the Barratt Impulsivity Scale (BIS) and the Defense Style Questionnaire (DSQ) were used to measure severity of psychiatric morbidity, impulsivity and defensive style, respectively. RESULTS: BIS was a highly significant predictor of categorical PD (ß = .13, SE = .03, p < .001), but not GSI and DSQ. BIS and GSI significantly predicted PD as a dimensional construct (ß = 0.32, SE = .08, t = 4.05, p < 0.001; and ß = 5.04, SE = 1.54, t = 3.28, p = 0.002, respectively). The diagnostic efficiency statistics found that BIS had greater sensitivity (.82) and specificity (.79), and overall predictive power (.87) of correctly identifying true positive and true negative PD diagnosis compared to the other two measures. CONCLUSIONS: BIS may be used in routine clinical practice as a screening measure to identify the presence of PD in complex presentations.

Vickers Micro-Hardness of New Restorative CAD/CAM Dental Materials: Evaluation and Comparison after Exposure to Acidic Drink.

CAD/CAM (computer-aided design/computer-aided manufacturing) for indirect restorative materials has been recently introduced in dentistry. The purpose of this study was to evaluate the change of the surface micro-hardness of different restorative CAD/CAM materials after exposure to a carbonated acidic drink (Coca-Cola, Coca-Cola Company, Milan, Italy). One hundred and eighty specimens of identical size (2 mm thickness) were obtained by sectioning each tested CAD/CAM block of four materials: a hybrid ceramic (CERASMART™, GC Corporation, Tokyo, Japan), a resin nano ceramic (Lava™ Ultimate, 3M, Monrovia, CA, USA), a nanohybrid composite (Grandio blocs, VOCO GmbH, Cuxhaven, Germany), and a zirconia-reinforced lithium silicate glass ceramic (VITA SUPRINITY® PC; VITA Zahnfabrik, Bad Sackingen, Germany). Forty-five specimens of each material were tested. Micro-hardness was measured at baseline, after 7 days and after 28 days. The data were analyzed. The micro-hardness of each material varied significantly after immersion in Coca-Cola. The nanohybrid composite had a high initial micro-hardness and the greatest percentage loss after acid exposure. The hybrid ceramic and the resin nano ceramic had similar percentage losses of micro-hardness values even if the second material had higher initial values. The zirconia-reinforced lithium silicate glass ceramic had the highest baseline values and the lowest percentage loss of micro-hardness. The different CAD/CAM materials presented different micro-hardness values before and after acid exposure.

Flexural Properties and Elastic Modulus of Different Esthetic Restorative Materials: Evaluation after Exposure to Acidic Drink.

BACKGROUND: Acidic beverages, such as soft drinks, can produce erosion of resin composites. The purpose of the present study was to investigate mechanical properties of different esthetic restorative materials after exposure to acidic drink. METHODS: Nine different composites were tested: nanofilled (Filtek Supreme XTE, 3M ESPE), microfilled hybrid (G-ænial, GC Corporation), nanohybrid Ormocer (Admira Fusion, Voco), microfilled (Gradia Direct, GC Corporation), microfilled hybrid (Essentia, GC Corporation), nanoceramic (Ceram.X Universal, Dentsply De Trey), supranano spherical hybrid (Estelite Asteria, Tokuyama Dental Corporation), flowable microfilled hybrid (Gradia Direct Flo, GC Corporation), and bulk fill flowable (SureFil SDR flow, Dentsply De Trey). Thirty specimens of each esthetic restorative material were divided into 3 subgroups (n=10): specimens of subgroup 1 were used as control, specimens of subgroup 2 were immersed in 50 ml of Coca Cola for 1 week, and specimens of subgroup 3 were immersed in 50 ml of Coca Cola for 1 month. Flexural strength and elastic modulus were measured for each material with an Instron Universal Testing Machine. Data were submitted to statistical analysis. RESULTS: After distilled water immersion, nanofilled composite showed the highest value of both flexural strength and elastic modulus, but its flexural values decreased after acidic drink immersion. No significant differences were reported between distilled water and acidic drink immersion for all other materials tested both for flexural and for elastic modulus values. CONCLUSIONS: Even if nanofilled composite showed highest results, acidic drink immersion significantly reduced flexural values.

Effect of different protective agents on enamel erosion: An in vitro investigation.

BACKGROUND: The purpose of this in vitrostudy was to compare the effect of different protective agents on enamel erosion by measuring mean percentage weight loss. MATERIAL AND METHODS: Extracted teeth were sectioned into uniform slabs and enamel specimens were randomly distributed to different groups. Initial weight of all enamel specimens was registered. The protective agents used in this study were Tooth Mousse, MI Paste Plus, Remin Pro and Remin Pro Forte. A control group was treated just with tap water. All the specimens were immersed in Coca-Cola for a total of 8 min at room temperature, dried and weighed. Enamel dissolution caused by acidic soft drink was analyzed: specimens were weighed after each immersion period and mean percent weight loss was calculated. Weight loss data were subjected to Analysis of Variance (One-way ANOVA) followed by Bonferroni's post hoc tests. RESULTS: All the groups showed a statistically significant loss of weight (p<0.01) during the testing periods, increased after 8 days (~55%) and 12 days (~70%) of exposure. Specimens treated with protective agents showed significantly lower % of weight loss especially with Remin Pro or Remin Pro Forte. CONCLUSIONS: Soft drinks can cause enamel erosion, but protective agents tested may enhance enamel resistance against erosion. Key words:Enamel, erosion, protective agents, soft drinks, toothpastes.

Effect of different finishing/polishing procedures on surface roughness of Ormocer-based and different resin composites.

BACKGROUND: The aim of this study was to evaluate and compare the surface roughness of six esthetic restorative materials (Gradia Direct Anterior, GC Corporation, Tokyo, Japan; Filtek Supreme XTE, 3M ESPE, St. Paul, MN, USA; Ceram.X Universal, Dentsply DeTrey, Konstanz, Germany; Essentia enamel, GC Corporation, Tokyo, Japan; Admira Fusion, Voco, Cuxhaven, Germany; and Estelite, Tokuyama Dental corporation, Taitou-ku, Tokyo, Japan) achieved using three different finishing and polishing techniques. MATERIALS AND METHODS: In this in vitro study Forty specimens of each material (6 mm in diameter, 2 mm high) were created and divided into four groups, one per each finishing and polishing procedure and a control group, only cured and not polished. All specimen preparation and finishing and polishing procedures were performed by the same investigator, to reduce variability, following strictly the manufacturer's instructions. Specimens were analyzed using a profilometer to measure the mean surface roughness (Ra, µm), and microscopy images were taken during the measurements through the microscope of the profilometer. Two-way ANOVA test was applied to determine significant differences with respect to material, finishing/polishing technique, and interaction between both variables. Post hoc comparison was done using Tukey's honestly significant difference test. Significance for statistical tests was predetermined at P < 0.05. RESULTS: Finishing and polishing procedure using tungsten carbide burs provided the best values in terms of surface roughness. All materials of this study treated with this method have provided superimposable values, and no material can be considered more performing than the others. Similar values were also found in the control group. CONCLUSION: This study demonstrated that the finishing technique with carbide burs produced an excellent surface smoothness, even if the best surface smoothness is achieved curing the restorative material under a polyester matrix.

Microhardness of different esthetic restorative materials: Evaluation and comparison after exposure to acidic drink.

BACKGROUND: Acidic beverages, such as soft drinks (orange juice and cola), can produce erosion of resin composites. The aim of this in vitro study was to evaluate the effect of immersion in acidic drink on the Vickers microhardness (VK) of different esthetic restorative materials (one nanohybrid Ormocer-based composite, one nanoceramic composite, one nanofilled composite, and one microfilled hybrid composite). MATERIALS AND METHODS: In this in vitro study, thirty specimens of each esthetic restorative material were divided into three subgroups (n = 10): specimens of group 1 were used as control, specimens of group 2 were immersed in 50 ml of acidic drink for 1 day, specimens of group 3 were immersed in 50 ml of acidic drink for 7 days. Data were analyzed by Shapiro-Wilk test to assess the normality of the distributions followed by nonparametric Kruskal-Wallis analysis of variance and Mann-Whitney U-test comparison test among groups. A significant level of α = 0.05 was set for comparison between the groups. RESULTS: Mann-Whitney U-test showed that each material showed lower microhardness values after immersion in acidic solution (P < 0.05). Paired t-test confirmed that microhardness for each composite did not change after immersion in distilled water (Control group) (P > 0.05). Significant changes were registered for all restorative materials after immersion in acidic solution for 1 day and 7 days (P < 0.05). CONCLUSION: The Filtek Supreme XTE, a nanofilled composite, and Admira Fusion, a nanohybrid ormocer-based composite, showed the best behavior. The Ceram X Universal (nanoceramic composite) although reached lower hardness values than the previous materials, but resisted well to the 1 week immersion in soft-drink. Finally, the Gradia Direct achieved the most disappointing results: Low microhardness values are justified by the nature of its filling (microfilled hybrid composite).

Shear bond strength of one-step self-etch adhesives to dentin: Evaluation of NaOCl pretreatment.

BACKGROUND: The aim of this study was to evaluate the influence of dentin pretreatment with NaOCl on shear bond strength of four one-step self-etch adhesives with different pH values. MATERIAL AND METHODS: Bovine permanent incisors were used. Four one-step self-etch adhesives were tested: Adper™ Easy Bond, Futurabond NR, G-aenial Bond, Clearfil S3 Bond. One two-step self-etch adhesive (Clearfil SE Bond) was used as control. Group 1- no pretreatment; group 2- pretratment with 5,25 % NaOCl; group 3- pretreatment with 37 % H3PO4 etching and 5,25 % NaOCl. A hybrid composite resin was inserted into the dentin surface. The specimens were tested in a universal testing machine. The examiners evaluated the fractured surfaces in optical microscope to determine failure modes, quantified with adhesive remnant index (ARI). RESULTS: Dentin pretreatment variably influenced bond strength values of the different adhesive systems. When no dentin pretreatment was applied, no significant differences were found (P >.05) among four adhesives tested. No significant differences were recorded when comparing NaOCl pretreatment with H3PO4 + NaOCl pretreatment for all adhesive tested (P >.05) except Clearfil S3 Bond that showed higher shear bond strength values when H3PO4 was applied. Frequencies of ARI scores were calculated. CONCLUSIONS: The influence of dentin pretreatment with NaOCl depends on the composition of each adhesive system used. There was no difference in bond strength values among self-etch adhesives with different pH values. Key words:Dentin, pretreatment, self-etch adhesives.

Analysis of the current world biofuel production under a water-food-energy nexus perspective.

This paper assesses the sustainability of bioenergy production under a nexus perspective through a new efficiency type index. The index describes 1st generation biofuel production under the perspective of the implied consumption of natural resources. We consider the sustainability of energy production as a sequence of steps, each characterised by its efficiency, and propose an index which returns an overall efficiency value describing the adequacy or inadequacy of the considered processes under a nexus perspective. The direct application of the nexus index entails an indication of the possible improvements needed to move production towards most sustainable processes or places. Moreover, it allows evaluating the efficiency of the main crops currently used in biofuel production with respect to the water-food-energy nexus. The results depict countries presently capable of performing sustainable production of 1st generation biofuel from particular crops. Furthermore, the analysis of the single components of the nexus index allows understanding the effects of possible improvements (e.g. soil and water management, new generation biofuels) on the overall production efficiency under a nexus perspective.

Experimental demonstration of a 24-port packaged multi-microring network-on-chip in silicon photonic platform.

A 24-port packaged multi-microring optical network-on-chip has been tested for simultaneous co- and counter-propagating transmissions at the same wavelength at 10 Gbps. In the co-propagating scenario communications up to five hops with one interfering signal have been tested, together with transmissions impaired by up to three interfering signals. In the counter-propagating scenario the device performance has been investigated exploiting the ring resonators in both shared-source and shared-destination configurations. The spectral characterization is in good agreement with the theoretical results. Bit-error-rate measurements indicate power penalties at BER=10-9 limited to (i) 0.5 dB in the co-propagating scenarios independently from the number of interfering transmissions, (ii) 0.8 dB in the counter-propagating scenario with shared-source configuration, and (iii) 2 dB in the counter-propagating scenario with shared-destination configuration.

Remineralizing effect of a zinc-hydroxyapatite toothpaste on enamel erosion caused by soft drinks: Ultrastructural analysis.

BACKGROUND: The aim of the present in vitro study was to evaluate the protective effects of a zinc-hydroxyapatite toothpaste on repairing enamel erosion produced by a soft drink (Coca-Cola) compared to toothpastes with and without fluoride using Scanning Electron Microscopy (SEM). MATERIAL AND METHODS: Fifty specimens were assigned to 5 groups of 10 specimens each. (Group 1: no erosive challenge, no toothpaste treatment, group 2: erosive challenge, no toothpaste treatment, 3: erosive challenge, toothpaste without fluoride, group 4: erosive challenge, fluoride toothpaste treatment, group 5: erosive challenge, zinc-hydroxyapatite toothpaste treatment). Repeated erosive challenges were provided by immersing bovine enamel specimens (10 per group) in a soft drink for 2 min (6mL, room temperature) at 0, 8, 24 and 32 h. After each erosive challenge, the toothpastes were applied neat onto the surface of specimens for 3 min without brushing and removed with distilled water. Between treatments the specimens were kept in artificial saliva. The surface of each specimen was imaged by SEM. RESULTS: Statistically significant differences were found between the samples used as control and those immersed in Coca-Cola (group 1 and 2): indeed among all groups the highest grade of damage was found in group 2. Instead the lowest grade was recorded in the samples of group 5 (Zinc hydroxyapatite toothpaste). CONCLUSIONS: The results of this study confirmed the potential benefit the Zn-HAP technology could provide in protecting enamel from erosive acid challenges. The treatment of erosively challenged enamel with Zn-Hap toothpaste showed a clear protective effect. Key words:Dental erosion, enamel, SEM, toothpaste.

Radiographic technical quality of root canal treatment performed by a new rotary single-file system.

AIM: The aim of the present study was to evaluate radiographically the technical quality of root canal filling performed by postgraduate students with a new single-file Nickel-Titanium System (F6 Skytaper Komet) in clinical practice. METHODS: Records of 74 patients who had received endodontic treatment by postgraduate students at the School of Dentistry, Faculty of Medicine, University of Pavia in the period between September 2015 and April 2016 were collected and examined: the final sample consisted 114 teeth and 204 root canals. The quality of endodontic treatment was evaluated by examining the length of the filling in relation to the radiographic apex, the density of the obturation according to the presence of voids and the taper of root canal filling. Chi-squared analysis was used to determine statistically significant differences between the technical quality of root fillings according to tooth's type, position and curvature. RESULTS: The results showed that 75,49%, 82,84% and 90,69% of root filled canals had adequate length, density and taper respectively. CONCLUSIONS: Overall, the technical quality of root canal fillings performed by postgraduates students was acceptable in 60,78% of the cases.

Four years comparative follow-up evaluation of community-based, step-down, and residential specialist psychodynamic programmes for personality disorders.

Although the fulcrum of service provision for personality disorder (PD) has shifted from hospital-based to psychodynamically- and cognitively-oriented outpatient programmes, very few studies have attempted to compare specialist moderate intensity outpatient programmes with specialist high-intensity residential models, or to explore whether a period of inpatient treatment may be necessary to improve outcome and prognosis. In this article, we prospectively compare changes over a 4-year period in 3 groups of patients with personality disorders (N = 162) treated in a specialist community-based (CBP, N = 30), a step-down (RT-CBP, N = 87), and a specialist residential programme (RT, N = 45) in psychiatric distress, deliberate self-injury, and suicide attempt using multilevel modelling and multivariate logistic regression analyses. The results showed that percentages of early-dropout were significantly different (p = .0001) for the 3 programmes (CBP = 13.4%, RT-CBP = 10.2%, and RT = 41.4%). A significant interaction between treatment model and time was found for psychiatric distress (p = .001), with CBP and RT-CBP achieving more marked changes (g = 1.20 and g = 0.68, respectively) compared to RT (g = 0.30) at 48-month follow-up. CBP and RT-CBP were found to significantly reduce impulsive behaviour (deliberate self-injury and suicide attempt) compared to RT. Severity of presentation was not found to be a significant predictor of outcome. Long-term RT showed no advantage over long-term CBP, either as stand-alone or as step-down treatment. Replication may be needed to confirm generalizability of results, and a number of limitations in the study design may moderate the inferences that can be drawn from the results.

Influence of dentin pretreatment on bond strength of universal adhesives.

Objective: The purpose of the present study was to compare bond strength of different universal adhesives under three different testing conditions: when no pretreatment was applied, after 37% phosphoric acid etching and after glycine application. Materials and methods: One hundred and fifty bovine permanent mandibular incisors were used as a substitute for human teeth. Five different universal adhesives were tested: Futurabond M+, Scotchbond Universal, Clearfil Universal Bond, G-Premio BOND, Peak Universal Bond. The adhesive systems were applied following each manufacturer's instructions. The teeth were randomly assigned to three different dentin surface pretreatments: no pretreatment agent (control), 37% phosphoric acid etching, glycine pretreatment. The specimens were placed in a universal testing machine in order to measure and compare bond strength values. Results: The Kruskal-Wallis analysis of variance and the Mann-Whitney test were applied to assess significant differences among the groups. Dentin pretreatments provided different bond strength values for the adhesives tested, while similar values were registered in groups without dentin pretreatment. Conclusions: In the present report, dentin surface pretreatment did not provide significant differences in shear bond strength values of almost all groups. Acid pretreatment lowered bond strength values of Futurabond and Peak Universal Adhesives, whereas glycine pretreatment increased bond strength values of G Praemio Bond adhesive system.

Comparative cytotoxicity evaluation of eight root canal sealers.

BACKGROUND: The aim of the present study is to evaluate and compare the cytotoxic effects of eight root canal sealers (BioRoot RCS, TotalFill BC Sealer, MTA Fillapex, Sealapex, AH Plus, EasySeal, Pulp Canal Sealer, N2) on immortalized human gingival fibroblasts over a period of 24, 48 and 72 hours. MATERIAL AND METHODS: Immortalized human gingival fibroblast-1 HGF-1 (ATCC CRL-2014) were incubated. Root canal sealers were then placed into sterile, cylindrical Teflon moulds. The extraction was made eluting the sealers in cell culture medium. Cells (1 × 104) were seeded in each well of a 96-well plate and incubated for 24 h at 37°C. Cultures were then exposed to 100 µL of the extracts medium. The percentage of viable cells in each well was calculated relative to control cells set to 100%. RESULTS: BioRoot RCS and TotalFill BC Sealer extracted for 24h showed no cytotoxic effect, while it was mild by using 48 and 72 h extracts. No cytotoxic effect was measured by using AH Plus medium eluted for 24 h, while it was moderate after 48 h and severe after 72 h. Pulp Canal Sealer, Sealapex and N2 showed moderately cytotoxic activity for all the extraction times. EasySeal and MTA Fillapex remained severely or borderline mildly cytotoxic for all the extraction times. CONCLUSIONS: In the present study only BioRoot RCS, TotalFill BC Sealer and AH Plus showed no cytotoxic effects at least in the first 24h. All the other sealers revealed moderately or severely cytotoxic activity during all the extraction times. Key words:Cytotoxicity, gingival fibroblast, MTT test, root canal sealer.