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1.
Quintessence Int ; 52(2): 132-137, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33433079

RESUMEN

The extraction of a tooth with root resorption can be a complicated procedure and can result in the removal of a significant amount of alveolar bone. In the anterior maxilla, esthetic rehabilitation of damaged sites with implant-supported crown could require multiple surgeries. Patients often ask for an alternative, and minimally invasive treatments are generally preferred. In this paper, a clinical case of implant-supported crown in a site affected by root resorption is described. Immediate implant was placed leaving some root fragments in the osteotomy site, thus avoiding invasive extractive surgeries. A minimally invasive flapless technique with a computer-guided implant placement procedure was used. After ?8 years, clinical and radiologic data were stable, gingival tissues around the implant appeared healthy, no dark translucency appeared through marginal gingiva around the implant, and there was no pathologic probing pocket depth ?or bleeding on probing. In the presence of root resorption and ankylosis, computer-guided surgery could be helpful to prepare a precise implant site through various tissues, such as partially resorbed root remnants. (Quintessence Int 2021;52:132-137; doi: 10.3290/j.qi.a45432).


Asunto(s)
Implantes Dentales de Diente Único , Implantes Dentales , Carga Inmediata del Implante Dental , Computadores , Coronas , Implantación Dental Endoósea , Prótesis Dental de Soporte Implantado , Estética Dental , Humanos , Maxilar/cirugía , Extracción Dental , Resultado del Tratamiento
2.
Eur J Dent Educ ; 2020 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-33269536

RESUMEN

INTRODUCTION: The outbreak and diffusion of the novel SARS-CoV2 coronavirus have caused an emergency status in the dental education system. MATERIALS AND METHODS: An anonymous survey composed of 34 questions was delivered to students of the Master Degree Program in Dentistry and Dental Prosthodontics of the Universities of Emilia-Romagna, the fifth Italian region most affected by the pandemic. The psychological impact of COVID-19 was assessed by means of the Generalized Anxiety Disorder-7 scale (GAD-7). Numerically recoded data were analysed using the Analysis of Variance (ANOVA), whilst to investigate the association between quantitative variables, the Pearson correlation coefficient (R) was computed. RESULTS: The questionnaire was completed by 399 students (75%) out of 532. Most students experienced difficulties in working at the thesis during the COVID-19 emergency. For over half of them online teaching could only partially replace traditional face-to-face lessons. The negative impact on the study career was judged as particularly high by sixth-year students. Clinical training activities were considered as exposing to the risk of contracting COVID-19 infection by the majority of the students. The level of concern of contracting COVID-19 infections during future university activities was positively correlated to risk perception related to clinical training. CONCLUSION: The results of this survey could be used to train students to a correct risk assessment. Students reported experiencing concern while thinking of COVID-19 and 6.5% of them showed symptoms related to high levels of anxiety. These data may guide Universities in trying to reduce students' anxiety by means of correct communication strategies.

3.
Materials (Basel) ; 13(21)2020 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-33172215

RESUMEN

In the present study, the cytotoxicity and the antimicrobial activity of two silver citrate-based irrigant solutions were investigated. Cytotoxicity of various concentrations (0.25%, 0.5%, 1%, 2.5%, 5%) of both solutions (BioAKT and BioAKT Endo) was assessed on L-929 mouse fibroblasts using the MTT assay. For the quantitative analysis of components, an infrared (I.R.) spectroscopy was performed. The minimum inhibitory and minimal bactericidal concentrations (M.I.C. and M.B.C., respectively) were ascertained on Enterococcus faecalis strain ATCC 4083. For biofilm susceptibility after treatment with the irrigating agent, a minimum biofilm eradication concentration (M.B.E.C.) and confocal laser scanning microscope (C.L.S.M.) assays were performed. Quantification of E. faecalis cell biomass and percentage of live and dead cells in the biomass was appraised. Normality of data was analyzed using the D'Agostino & Pearson's test and the Shapiro-Wilk test. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test. Both silver citrate solutions showed mouse fibroblasts viability >70% when diluted to 0.25% and 0.5%. Conversely, at higher concentrations, they were extremely cytotoxic. F.T.-IR spectroscopy measurements of both liquids showed the same spectra, indicating similar chemical characteristics. No substantial contrast in antimicrobial activity was observed among the two silver citrate solutions by using broth microdilution methods, biofilm susceptibility (MBEC-HTP device), and biomass screening using confocal laser scanning microscopy (C.L.S.M.) technique. Both solutions, used as root canal irrigants, exhibited significant antimicrobial activity and low cytocompatibility at dilutions greater than 0.5%.

4.
Quintessence Int ; : 2-7, 2020 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-33118005

RESUMEN

The extraction of a tooth with root resorption can be a complicated procedure and can result in the removal of a significant amount of alveolar bone. In the anterior maxilla, esthetic rehabilitation of damaged sites with implant-supported crown could require multiple surgeries. Patients often ask for an alternative, and minimally invasive treatments are generally preferred. In this paper, a clinical case of implant-supported crown in a site affected by root resorption is described. Immediate implant was placed leaving some root fragments in the osteotomy site, thus avoiding invasive extractive surgeries. A minimally invasive flapless technique with a computer-guided implant placement procedure was used. After 8 years, clinical and radiologic data were stable, gingival tissues around the implant appeared healthy, no dark translucency appeared through marginal gingiva around the implant, and there was no pathologic probing pocket depth or bleeding on probing. In the presence of root resorption and ankylosis, computer-guided surgery could be helpful to prepare a precise implant site through various tissues, such as partially resorbed root remnants.

5.
Materials (Basel) ; 13(17)2020 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-32847048

RESUMEN

To evaluate the properties of two nickel-titanium (NiTi) reciprocating endodontic instruments (commercially known as Procodile and Reziflow), a total of 40 size 25 and 0.06 taper new Procodile and Reziflow instruments (n = 20) were subjected to cyclic fatigue tests (60° angle of curvature, 5-mm radius) at 20 °C and 37 °C and a torsional test based on ISO 3630-1. The fracture surface of each fragment was examined. The morphological, mechanical, chemical, thermal, and phase composition characteristics of the files were investigated by field-emission gun scanning electron microscopy (FEG-SEM) equipped with an energy-dispersive X-ray (EDX) detector, focused ion beam analysis (FIB), micro-Raman spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Auger electron spectroscopy (AES). Reziflow showed higher cyclic fatigue resistance than Procodile at 37 °C (p < 0.05). The maximum torsional strength of Procodile was lower than that of Reziflow (p < 0.05). No difference was found between their angular rotations to fracture (p > 0.05). SEM, FIB, Micro-Raman, and AES analyses revealed the presence of an Nb/Nb2O5 coating on the Procodile surface. DSC and XRD analysis confirmed that both files consist of an almost austenitic phase structure at 37 °C. The cyclic fatigue resistance of Procodile and Reziflow significantly decreases upon exposure to body temperature.

6.
J Oral Implantol ; 2020 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-32780815

RESUMEN

In 2020, a highly infective new pathogen (Sars-CoV-2) spread from China to the whole globe, and became responsible of an acute respiratory syndrome, often asymptomatic but potentially lethal, named COVID-19. Airborne and direct contact contamination are the major infection pathways of Sars-CoV-2 and it has been shown that virus spread can also happen in absence of clinical symptoms. SARS-CoV-2 transmission during dental procedures can happen through inhalation of droplets from infected patients or direct contact with mucous membranes, oral fluids, and contaminated instruments. Both sinus lift and implant surgeries often involve bleeding and exposure to oral fluids, and a rubber dam could be used to reduce direct contact and the amount of potentially infected aerosol. The aim of this short case presentation is to illustrate how the use of a rubber dam could be extremely useful in preventing COVID-19 exposure during flapless trans-crestal sinus lift procedures.

7.
Artículo en Inglés | MEDLINE | ID: mdl-32650590

RESUMEN

This review provides a detailed description of matrix metalloproteinases (MMPs), focusing on those that are known to have critical roles in bone and periodontal disease. Periodontal disease is an inflammatory process initiated by anaerobic bacteria, which promote the host immune response in the form of a complex network of molecular pathways involving proinflammatory mediators such as cytokines, growth factors, and MMPs. MMPs are a family of 23 endopeptidases, collectively capable of degrading virtually all extracellular matrix (ECM) components. This study critically discusses the available research concerning the involvement of the MMPs in periodontal disease development and progression and presents possible therapeutic strategies. MMPs participate in morphogenesis, physiological tissue turnover, and pathological tissue destruction. Alterations in the regulation of MMP activity are implicated in the manifestation of oral diseases, and MMPs comprise the most important pathway in tissue destruction associated with periodontal disease. MMPs can be considered a risk factor for periodontal disease, and measurements of MMP levels may be useful markers for early detection of periodontitis and as a tool to assess prognostic follow-ups. Detection and inhibition of MMPs could, therefore, be useful in periodontal disease prevention or be an essential part of periodontal disease therapy, which, considering the huge incidence of the disease, may greatly improve oral health globally.


Asunto(s)
Metaloproteinasas de la Matriz , Enfermedades Periodontales , Periodontitis , Citocinas , Humanos , Enfermedades Periodontales/metabolismo , Periodontitis/metabolismo
8.
Odontology ; 108(3): 396-405, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32112364

RESUMEN

This study aimed to evaluate the antimicrobial and antibiofilm activity of two chelating agents: ethylenediaminetetraacetic acid (EDTA) combined or not with detergents, and etidronic acid combined with sterile saline. The bacterial inhibitory and bactericidal concentrations (MIC and MBC, respectively) were determined on Enterococcus faecalis ATCC 4083 strain. Antimicrobial tests were performed on a biofilm model after treatment with the chelating agents at different times (1, 3, and 5 min) using a biofilm eradication concentration (MBEC) and confocal laser scanning microscope (CLSM) assays. Quantification of cell biomass and percentage of live and dead cells in the biomass was assessed for each group. The normality of the distributions for each variable was assessed using the D'Agostino and Pearson's omnibus normality test. The comparison of bacterial viability among groups and between any two groups was performed using the non-parametric Kruskal-Wallis one-way analysis of variance and the Dunn's test, respectively. No significant between-group difference was observed regarding biomass reduction. On the other hand, EDTA combined with detergents displayed a substantial increase of the dead bacteria ranging between 35 and 43%; whereas, the number of cells killed in the control group and in the other treated groups always ranged between 1 and 6%, at all experimental times. The addition of detergents to EDTA can improve its anti-biofilm activity by reducing EPS production and enhancing the killing of sessile bacterial cells. Clinical relevance EDTA presents a relevant antimicrobial activity when combined with surface-active agents.


Asunto(s)
Antiinfecciosos , Enterococcus faecalis , Antibacterianos , Biopelículas , Ácido Edético , Ácido Etidrónico , Microscopía Confocal , Irrigantes del Conducto Radicular
9.
J Endod ; 46(3): 431-436, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31911005

RESUMEN

INTRODUCTION: The aim of this study was to compare the influences from different access angles and curvature radii on cyclic fatigue resistance of nickel-titanium rotary files. METHODS: Two file systems (2Shape [TS; MicroMega, Besançon, France] and HyFlex CM [HCM; Coltène/Whaledent, Allstätten, Switzerland]) were used. A total of 192 instruments of TS #25/.04 (TS1), TS #25/.06 (TS2), HCM #25/.04, and HCM #25/.06 were evaluated at 3 insertion angles (0°, 10°, and 20°) and 2 radii (5 mm and 3 mm) in 16-mm stainless steel artificial canals with a 60° curvature. Cyclic fatigue resistance was determined by the number of cycles to failure (NCF) using a customized testing device. Data were analyzed statistically with the significance level established at 95%. RESULTS: In the 3-mm radius canal, the instruments showed lower cyclic fatigue resistance than in the 5-mm radius canal (P < .05). HCM #25/.06 and all .04 taper instruments had a significant NCF reduction at 20° and 10° in the 3-mm radius canal (P < .05), whereas TS2 showed no significant differences. In the 5-mm radius of curvature, although .06 taper instruments had no significant NCF reduction for each angle tested, .04 taper files exhibited significant NCF reduction when tested at 20° (P < .05). Comparing the same size instruments, HCM had higher NCF than TS (P < .05). Instruments with a .04 taper exhibited higher NCF than the .06 ones with the same heat treatment (P < .05). CONCLUSIONS: An inclined insertion into the canals decreased cyclic fatigue resistance of thermal-treated instruments with a .04 taper at all radii of curvature tested. The synergistic effect of a small radius of curvature and access angulation of heat-treated instruments decreases their fatigue resistance.


Asunto(s)
Aleaciones Dentales , Instrumentos Dentales , Falla de Equipo , Níquel , Titanio , Cavidad Pulpar , Diseño de Equipo , Ensayo de Materiales , Radio (Anatomía) , Preparación del Conducto Radicular
10.
Clin Oral Investig ; 24(2): 1001-1011, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31286261

RESUMEN

OBJECTIVES: To compare the clinical and histological response of supracrestal periodontal tissues to subgingival composite restorations versus natural root surfaces MATERIAL AND METHODS: In 29 subjects with a single tooth requiring subgingival restorations, a deep margin elevation (DME) procedure with composite resin was applied. Full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), and focal probing depth (PD) were measured at baseline, before DME, and after 3 months. The distance between the coronal marked (CM) point to the apical margin of the composite reconstruction (AMR), at baseline, and to the tip of the periodontal probe inserted to reach the bottom of the sulcus (APP), 3 months later, was measured. An all-around secondary flap, harvested to ensure the subsequent single-crown prosthetic rehabilitation was histologically processed. The histological inflammation degree was evaluated in areas of gingival tissues adjacent to the composite (group B) and adjacent to the natural surface of each single tooth (group A). RESULTS: Significant FMPS, FMBS, and PD decreases were observed (p < 0.05). CM-AMR and CM-APP were significantly different (p < 0.05), suggesting an attachment gain after 3-months. The inflammation level of gingival tissue was similar in groups A and B (p > 0.05). CONCLUSIONS: For the first time, this topic was clinically and histologically studied in humans. Subgingival restorations resulted compatible with gingival health, with levels similar to that of untreated root surfaces. CLINICAL RELEVANCE: Deep margin elevation procedure produces favorable clinical and histological outcomes allowing a routine utilization in reconstructive dentistry.


Asunto(s)
Periodoncio , Resinas Compuestas , Coronas , Encía , Humanos , Índice Periodontal
11.
Int J Mol Sci ; 20(19)2019 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-31590328

RESUMEN

Bone physiology relies on the delicate balance between resorption and formation of its tissue. Bone resorption depends on a process called osteoclastogenesis in which bone-resorbing cells, i.e., osteoclasts, are produced by the differentiation of more undifferentiated progenitors and precursors. This process is governed by two main factors, monocyte colony-stimulating factor (M-CSF) and receptor activator of NFκB ligand (RANKL). While the former exerts a proliferating effect on progenitors/precursors, the latter triggers a differentiation effect on more mature cells of the same lineage. Bone homeostasis requires a perfect space-time coordination of the involved signals. When osteoclastogenesis is poorly balanced with the differentiation of the bone forming counterparts, i.e., osteoblasts, physiological bone remodelling can turn into a pathological state, causing the systematic disruption of bone tissue which results in osteopenia or osteolysis. Examples of these conditions are represented by osteoporosis, Paget's disease, bone metastasis, and multiple myeloma. Therefore, drugs targeting osteoclastogenesis, such as bisphosphonates and an anti-RANKL monoclonal antibody, have been developed and are currently used in the treatment of such diseases. Despite their demonstrated therapeutic efficacy, these agents are unfortunately not devoid of side effects. In this regard, a condition called osteonecrosis of the jaw (ONJ) has been recently correlated with anti-resorptive therapy. In this review we will address the involvement of osteoclasts and osteoclast-related factors in the pathogenesis of ONJ. It is to be hoped that a better understanding of the biological mechanisms underlying bone remodelling will help in the design a medical therapeutic approach for ONJ as an alternative to surgical procedures.


Asunto(s)
Osteonecrosis de los Maxilares Asociada a Difosfonatos/metabolismo , Diferenciación Celular , Osteoclastos/metabolismo , Animales , Osteonecrosis de los Maxilares Asociada a Difosfonatos/epidemiología , Osteonecrosis de los Maxilares Asociada a Difosfonatos/patología , Humanos , Osteoclastos/citología
12.
Odontology ; 107(4): 521-529, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31197618

RESUMEN

The aim of this study was to evaluate the surface tension and the antimicrobial activity in infected dentin of a NaOCl solution combined with an etidronate powder (Dual Rinse® HEDP), compared to pure NaOCl and the classic NaOCl + EDTA irrigating sequence, respectively. The surface tension of three irrigants was measured by Wilhelmy technique. To evaluate the antimicrobial activity of the solutions, 26 human teeth were contaminated for 5 days with E. faecalis. After bacterial contamination, ten samples were irrigated with NaOCl followed by EDTA, another ten with NaOCl/Dual Rinse® HEDP, and four were used as positive controls. Two specimens not contaminated were used as negative controls. After live/dead BacLight staining, samples were examined by CLSM for analyzing % of residual live and dead cells. Comparison of bacterial viability between and within groups was performed using the Mann-Whitney test for independent samples and the Wilcoxon signed-rank test, respectively. The mean surface tension of EDTA was significantly lower than that of the other irrigants tested (p < 0.001). Conversely, the surface tension of NaOCl/Dual Rinse® HEDP solution was significantly higher than that of all the other solutions (p < 0.001). Residual bacterial viability in the NaOCl/Dual Rinse® HEDP (1.71%) was significantly lower (p = 0.019) than in the NaOCl + EDTA group (3.77%). All of the experimental groups showed significantly lower proportion of viable bacterial cells than the positive control group (p < 0.01). Clinical relevance adding etidronate to NaOCl increases its antimicrobial effect in dentinal tubules even though increases its surface tension.


Asunto(s)
Ácido Etidrónico , Irrigantes del Conducto Radicular , Dentina , Desinfección , Ácido Edético , Enterococcus faecalis , Humanos , Hipoclorito de Sodio , Tensión Superficial
13.
Clin Oral Investig ; 23(8): 3407, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30937542

RESUMEN

The author names in the original version of this article were inadvertently interchange. Correct presentation of author names is reflected here.

14.
Odontology ; 107(4): 473-481, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30924034

RESUMEN

The aim of this study was to characterize the main features and the usage-induced degradation of the Genius file after four severely curved root canal instrumentations and to compare their properties to the Reciproc files. Brand new and ex vivo used files were analysed by scanning electron microscopy (SEM) with energy-dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), X-ray diffraction (XRD), optical metallography, and nano-indentation to disclose their morphological, chemical, mechanical, thermal, and phase composition features. Nano-indentation data were statistically analysed using the Student's t test for normal distribution or the Kolmogorov-Smirnov test for not-normal distributions. SEM analysis showed the presence of micro-cracks near the tip on both files after ex vivo usage test. EDS analysis confirmed that both files are manufactured from an almost equiatomic NiTi alloy. DSC analysis revealed that the transition temperature of the Genius is below 20 °C, while that of the Reciproc is above 20 °C. XRD analysis of Genius files identified cubic B2 austenite with minor peaks of residual monoclinic B19 martensite, while the contemporaneous presence of martensite, austenite and hexagonal R-phase was observed in the Reciproc files. Significant differences in nanohardness and modulus of elasticity (P < .05) were observed in both Genius and Reciproc files before and after use. The collected results showed that both instruments can be safely used as single-use files.


Asunto(s)
Níquel , Titanio , Aleaciones , Rastreo Diferencial de Calorimetría , Aleaciones Dentales , Instrumentos Dentales , Elasticidad , Diseño de Equipo , Humanos , Ensayo de Materiales , Preparación del Conducto Radicular , Propiedades de Superficie
15.
Clin Oral Investig ; 23(8): 3367-3377, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30519823

RESUMEN

OBJECTIVES: Retrospective description of the 10-year success rate of endodontic treatments with Thermafil (TF). MATERIALS AND METHODS: Patients treated by postgraduate students in an Endodontics Master's Program (2006-2008) were enrolled. All treated root canals were filled with TF and AH Plus. Teeth satisfying the inclusion criteria (206 teeth in 89 patients) were reexamined clinically and radiographically to estimate a 10-year survival and periapical health. Demographic and medical data were registered; collected information included pre-, intra-, and postoperative variables. Teeth were classified as "healthy" (PAI ≤ 2 in absence of signs/symptoms), "endodontically diseased" (presenting at least one of the following: PAI ≥ 3, signs/symptoms, retreated in the course of the follow-up, or extracted for endodontic reasons), or "non-endodontically diseased" (extracted for non-restorable fractures or periodontal disease). For teeth lost during the 10-year follow-up, details and reason of extraction were analyzed. Two PAI-calibrated examiners assessed outcomes blinded to preoperative status. Bivariate and multilevel analyses were performed (α level set at 0.05). RESULTS: At 10 years, 179 (87%) teeth survived and 27 were extracted: 20 for non-endodontic reasons (excluded from success analysis) and 7 for endodontic reasons (considered "endodontically diseased"). Multilevel analysis revealed that the probability of extraction was increased by the presence of preoperative pain (odds ratio = 6.720; 95% confidence interval, 1.483-30.448) and by maxillary location (odds ratio = 2.950; 95% confidence interval, 1.043-8.347). Concerning periapical status, 159/186 teeth (85%) were assessed as "healthy." Multilevel analysis confirmed that maxillary location (odds ratio = 3.908; 95% confidence interval, 1.370-11.146), presence of flare up (odds ratio = 9.914; 95% confidence interval, 2.388-41.163), and fracture occurrence (odds ratio = 35.412; 95% confidence interval, 3.366-372.555) decreased the odds of healing, respectively. CONCLUSIONS: After 10 years, teeth filled with Thermafil in a specialist master's program presented a survival and a periapical health comparable to cohorts where root canals were filled with other obturation techniques. CLINICAL RELEVANCE: Carrier-based techniques provide time savings for clinicians while satisfying clinical quality criteria for the root filling and consequently the clinical outcome.


Asunto(s)
Cavidad Pulpar , Tratamiento del Conducto Radicular , Femenino , Humanos , Masculino , Estudios Retrospectivos , Resultado del Tratamiento
16.
Clin Oral Investig ; 23(7): 3095-3102, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30397734

RESUMEN

OBJECTIVES: To evaluate the impact of a modified motion on the fatigue life of four brands of nickel-titanium (NiTi) reciprocating instruments. MATERIALS AND METHODS: Cyclic fatigue (CF) resistance of 160 instruments was evaluated in an artificial stainless-steel canal (90° angle, 5-mm radius of curvature). WaveOne and WaveOne Gold (Denstply Maillefer, Baillagues, Switzerland) and Reciproc and Reciproc Blue (VDW, Munich, Germany) were tested with two different motions: (1) X-Smart Plus (Denstply Maillefer) endodontic motor and (2) a 4:1 contra-angle with an experimental motion (EVO) with different rotation angles and based on a sinusoidal acceleration. Motions with X-Smart Plus and EVO were recorded and analyzed at a reduced speed with VLC Media Player software for a more accurate analysis. Mean half-life, beta, and eta Weibull parameters were determined and compared. RESULTS: Reciproc Blue resulted the most resistant instruments either with EVO or X-Smart. WaveOne Gold lasted significantly longer than WaveOne with EVO (probability of 91%) while no significant differences were found with X-Smart. Considering NCF, Reciproc, WaveOne Gold, and Reciproc Blue lasted significantly longer with EVO (probabilities of 66%, 80%, and 89% respectively). WaveOne Gold showed the highest beta parameter. CONCLUSIONS: The experimental motion was found to have a positive impact on fatigue lifetime of reciprocating instruments. CLINICAL RELEVANCE: Current findings provide insight for future improvements in the clinical use of reciprocating files. Experimental motions may be considered when searching for additional strategies in order to increase the safer use of NiTi files during endodontic procedures.


Asunto(s)
Níquel , Preparación del Conducto Radicular , Titanio , Instrumentos Dentales , Diseño de Equipo , Falla de Equipo , Ensayo de Materiales
17.
J Conserv Dent ; 22(5): 449-453, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-33082660

RESUMEN

Aim: The aim of this study was to evaluate the cyclic fatigue resistance of Reciproc (RCP) and RPC Blue (RCPB) instruments used in continuous rotation, "RECIPROC" mode, and "WAVEONE" mode. Materials and Methods: Sixty RCP and 60 RCPB R25 files were used. For each file type, three groups (n = 20) were defined depending on the used kinematics: continuous rotation, "RECIPROC" mode, and "WAVEONE" mode. A stainless-steel artificial canal with 60° angle and 5-mm radius of curvature was milled reproducing the size and taper of the used files. The test device was electrically heated to 35°C to simulate the clinical environment. All files were reciprocated or rotated until fracture. The time to failure and the length of the fractured fragments were measured. A fractographic examination was performed by scanning the electron microscopy to confirm the cause of fracture. Collected data underwent a two-way analysis of variance (α = 0.05). Results: RCPB files exhibited better cyclic fatigue resistance than RCP. The "RECIPROC" motion yielded greater cyclic fatigue resistance than the "WAVEONE" movement; the least resistance was observed in the continuous rotation groups. No significant differences were found among groups in terms of length of the fractured fragment. The fractographic analysis confirmed that all scanned samples separated due to cyclic fatigue. Conclusions: Within the limitation of the present study, the "RECIPROC" mode increased the cyclic fatigue resistance of the tested instruments compared to "WAVEONE" mode and continuous rotation. To prevent RCP and RCPB file separation, motion kinematics other than the native "RECIPROC" movement should be discouraged in the clinical setting.

18.
Oral Dis ; 24(7): 1326-1335, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29766617

RESUMEN

INTRODUCTION: It is debated whether composite resin marginal/submarginal direct restoration can be usefully performed without inflammatory consequences. This histological study is the first human analysis aimed to compare, in the same tooth, the gingival tissue close to composite resin restorations with gingival tissue close to hard tissue. METHODS: Eight healthy patients with almost a residual strategic tooth needing endodontic therapy, and post-and-core restoration, then indirect prosthetic restoration, were selected. Direct margin relocation with composite resin was necessary to perform endodontic treatment. The crown lengthening with a secondary flap harvested was necessary to perform prosthetic rehabilitation. Three months after marginal relocation, the secondary flap was harvested, embedded in PMMA, 4-µm sectioned, and stained to analyze the inflammation degree. RESULTS: All patients completed post-and-core reconstruction and the planned prosthetic therapy, maintaining the stringent hygienic protocol plan. The inflammation level comparison, slightly lower in gingiva close to the teeth (3.62 ± 0.38) than in gingiva close to the composite (3.75 ± 0.26), results in a p-value of 0.11 after Wilcoxon test. CONCLUSIONS: Results highlight a minimal, statistically not significant difference in the inflammation degree after margin relocation, conceivably due to patients, teeth and cases selection, together with adopted stringent methodological and supportive measures.


Asunto(s)
Resinas Compuestas/efectos adversos , Gingivitis/inducido químicamente , Adulto , Femenino , Gingivitis/patología , Humanos , Masculino , Persona de Mediana Edad , Técnica de Perno Muñón
19.
G Ital Dermatol Venereol ; 153(3): 383-388, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29512980

RESUMEN

The involvement of the oral mucosa in patients affected by pemphigus vulgaris (PV), paraneoplastic, IgA pemphigus, and in some cases iatrogenic pemphigus is common and often a prelude to skin lesions. Intraepidermal bullae are caused by acantholysis, induced by IgG autoantibodies directed against the desmosomes and the domain of numerous keratinocytes self-antigens desmogleins (namely cadherins), thus supporting the autoimmune nature of the disease. Apoptosis may contribute to the acantholysis. Oral mucosal lesions are more commonly refractory to treatment compared to skin lesions and have been associated with disease duration, disease location and possibly the presence of HSV DNA in the oral cavity. Recent publications have stressed the positive role of Rituximab in early disease treatment.


Asunto(s)
Inmunoglobulina G/inmunología , Mucosa Bucal/patología , Pénfigo/patología , Acantólisis/inmunología , Apoptosis/inmunología , Autoanticuerpos/inmunología , Humanos , Factores Inmunológicos/uso terapéutico , Pénfigo/tratamiento farmacológico , Pénfigo/inmunología , Rituximab/uso terapéutico
20.
Odontology ; 106(4): 454-459, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29594826

RESUMEN

The aim of this study was to compare the effects of Manual Dynamic Agitation and Passive Ultrasonic Irrigation on sodium hypochlorite (NaOCl) penetration into dentinal tubules using its bleaching ability. Thirty-four single-rooted teeth with round-shaped root canals were distributed in two homogeneous groups and one control group, characterized by different NaOCl activation systems: Manual Dynamic Agitation and Passive Ultrasonic Irrigation. After instrumentation, all root canals were stained with 10% copper sulphate solution followed by 1% rubeanic acid alcohol solution under vacuum. Final irrigation was performed with 5 mL of 5.25% NaOCl solution for 1 min and activated with Manual Dynamic Agitation or Passive Ultrasonic Irrigation for another 1 min depending on the treatment group. The teeth were transversely sectioned at the middle portion of the apical, middle, and coronal thirds and observed under light microscope. NaOCl solution penetration was evaluated by measuring the percentage of bleached circumference of the root canal relative to the stained circumference, bleached areas, mean, and maximum penetration depth. No differences in the evaluated parameters were observed between groups (p > 0.05). Within groups, an increase of values was recorded from apical to coronal direction as for percentage of staining, percentage of bleaching and bleached area. NaOCl penetration into dentinal tubules did not significantly vary among the three levels. No significant differences in penetration of sodium hypochlorite into dentinal tubules when activated by means of Manual Dynamic Agitation or Passive Ultrasonic Irrigation were observed in the apical, middle, and coronal thirds of teeth with single straight round root canals.


Asunto(s)
Dentina/efectos de los fármacos , Irrigantes del Conducto Radicular/farmacocinética , Hipoclorito de Sodio/farmacocinética , Ultrasonido , Humanos , Técnicas In Vitro , Coloración y Etiquetado , Tensoactivos/farmacocinética , Irrigación Terapéutica
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