Experimental Periodontitis Worsens Dopaminergic Neuronal Degeneration.

Aim: To investigate the hypothesis supporting the link between periodontitis and dopaminergic neuron degeneration.

Materials And Methods: Adult male Wistar rats were used to induce dopaminergic neuronal injury with 6-hydroxydopamine (6-OHDA) neurotoxin and experimental periodontitis via ligature placement. Motor function assessments were conducted before and after periodontitis induction in controls and 6-OHDA-injury-induced rats.

Could Low-dose Cone-beam CT be Used for Endodontic Intraoperative Diagnosis?

Introduction: Cone-beam computed tomography (CBCT) allows three-dimensional evaluation and has high diagnostic accuracy of endodontic conditions. Considering that the most indicated protocol for endodontics should have smaller field-of-view and higher spatial resolution, a higher radiation dose may be associated. Thus, this study evaluated the accuracy of an optimized CBCT protocol for the detection of intraoperative endodontic complications.

Association between single-nucleotide polymorphisms in serotonin receptor 2A and melatonin receptor 1A genes and pain after root canal treatment.

Aim: This study aimed to investigate whether single-nucleotide polymorphisms (SNPs) in the genes encoding 5-HTR2A (5-Hydroxytryptamine (serotonin) receptor 2A) and MTNR1A (melatonin receptor 1A) may contribute to postoperative pain perception after root canal treatment. We hypothesised that SNPs in HTR2A and MTNR1A genes were associated with postoperative pain after root canal treatment.

Methodology: This genetic cohort study enrolled patients with single-rooted teeth diagnosed with pulp necrosis and asymptomatic apical periodontitis before root canal treatment.

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This case describes the treatment and follow-up of a mandibular molar in an 18-year-old female with a periapical cyst. Thus, it becomes important to know which options should we take when faced with a clinical situation that we cannot resolve through conventional methods, and which techniques and approaches we have to achieve treatment success. This case showed the treatment plan and follow-up, by the use of CBCT images, from a previously treated mandibular molar with a large periapical abscess and cystic lesion, in which, the first treatment plan approach was to make the endodontic retreatment.

Cytotoxicity and Inflammatory Mediators Release by Macrophages Exposed to Real Seal XT and Sealapex Xpress.

This study evaluated the cytotoxicity of Sealapex Xpress and Real Seal XT and their effect on macrophage activation. J774.1 macrophages were incubated with Sealapex Xpress and Seal Real XT (0.

Temperature changes affect the rheological properties of a silicone-based and an epoxy resin-based root canal sealers.

To evaluate temperature changes on the rheological properties (setting time and complex viscosity (η*)) of GuttaFlow Bioseal (GFB) and AH Plus Jet (AHPJ). Rheological measurements were performed in oscillating mode at the strain amplitude and angular frequency of 0.01% and 10 rad s , respectively.

Happiness among dentists: a multi-scale, multi-national study from 21 countries.

Objectives: The extent to which dentists are happy with their profession and their life has not been well studied. The present study aimed to explore the level of happiness, satisfaction with life and psychological well-being among a sample of dental professionals from 21 countries.

Materials And Methods: The sample comprised 2,200 dentists from 21 countries.

Micro-computed tomographic assessment of the variability and morphological features of root canal system and their ramifications.

Objectives: This study assessed the incidence and variability features of root canals system (RCS) and their ramifications according to Pucci & Reig (PR) (1944) and the American Association of Endodontists (AAE) (2017) by micro-computed tomography (μCT).

Methodology: 500 representative extracted human teeth of each tooth group (n=50) (maxillary/mandibular central and lateral incisors, canines, first and second premolars and molars) were scanned by μCT with a resolution of 26.70 μm.

Do Contaminating Substances Influence the Rheological Properties of Root Canal Sealers?

Introduction: This study evaluated the effect of residual substances derived from irrigant solutions and intracanal medications on the rheological properties of a silicone, gutta-percha, and bioactive glass-based sealer in comparison with an epoxy resin-based sealer.

Methods: Thin films of contaminants (0.5 μL) (3% sodium hypochlorite [NaOCl], chlorhexidine digluconate [CHX], 17% EDTA, calcium hydroxide, 40% citric acid, or distilled water [DW]) were applied along with freshly mixed GuttaFlow Bioseal (GFB; Coltene/Whaledent, Langenau, Germany) or AH Plus Jet (Dentsply DeTrey, Konstanz, Germany) on the lower plate of a dynamic rheometer.

The Effect of Diode and Er,Cr:YSGG Lasers on the Bond Strength of Fiber Posts.

Laser irradiation modifies the topography and composition of dentin surface aiming to increase the retention of bonded posts. To assess the effect of dentin irradiation with Er,Cr:YSGG or diode lasers on the bond strength of fiber posts using self-adhesive resin cement. Sixty bovine root canals were root-canal treated, post spaces were prepared, and subsequently fiber posts were cemented.

In vitro evaluation of tooth discoloration induced by regenerative endodontic therapy and the effectiveness of the walking bleach technique.

Background: The present study evaluated the coronal discoloration induced by different materials or blood as well as the effect of internal bleaching on discoloration.

Methods: After tooth color measurement at baseline with a sphere spectrophotometer (CIE L*a*b*), the root canals of molars were partially filled with white mineral trioxide aggregate (MTA), triple antibiotic paste (TAP), or a cotton pellet with bovine blood (control) was placed into the pulp chamber. The color changes were assessed at 30, 60, and 180 days after the procedure.

Changes in Geometry and Transportation of Root Canals with Severe Curvature Prepared by Different Heat-treated Nickel-titanium Instruments: A Micro-computed Tomographic Study.

Introduction: The aim of this study was to compare the shaping ability of 4 different nickel-titanium systems, considering their variation in alloy treatment, kinematics, and design, used to prepare canals with severe curvature using micro-computed tomographic analysis.

Methods: Thirty-two mesial roots of mandibular molars with severe curvature were matched based on similar morphologic dimensions and assigned to 4 experimental groups (n = 8) according to the canal preparation: ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Reciproc (RC; VDW GmbH, Munich, Germany), Reciproc Blue (RCB, VDW GmbH), and TRUShape (TRU; Dentsply Tulsa Dental Specialties, Tulsa, OK) systems. Changes in 2-dimensional (area and perimeter) and 3-dimensional (volume, surface area, and structure model index) morphologic parameters as well as canal transportation were compared among groups using the analysis of variance post hoc Tukey tests with the significance level set at 5%.

Genetic Polymorphisms in RANK and RANKL are Associated with Persistent Apical Periodontitis.

Introduction: The outcome of root canal treatment has been reported as intimately related to the host response. Genetic polymorphisms might be associated with apical periodontitis repair. The aim of this study was to evaluate the association between receptor activator of nuclear factor kappa B (RANK), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) genetic polymorphisms with persistent apical periodontitis (PAP) in Brazilian subjects.

Analysis of reciprocating system real-time torque variation during root canal preparation.

Objective: This study monitored real-time torque variation of the WaveOne Gold (WOG) and Reciproc Blue (RB) during root canal preparation of mandibular molars. Thirty-six mandibular molars were prepared with WOG Primary 25.07 (WOGP, n = 36) and the RB R25 25.

Effect of radiotherapy on the chemical composition of root dentin.

Background: The radiotherapy can directly affect the bond strength of the adhesive materials, interfering in the prognosis of restorative treatments, which may be caused by chemical changes in dentin structure.

Methods: Twenty inferior homologues premolars were distributed in 2 groups (in vitro study) (n = 10): nonirradiated and irradiated. The specimens were submitted to the analysis of phosphate (ν PO ;ν PO ;ν PO ), carbonate (ν CO ), amide I, CH , amide III, and amide I/III ratio by confocal Raman spectroscopy.

How to improve root canal filling in teeth subjected to radiation therapy for cancer.

The aim of this study was to evaluate the influence of radiation therapy on root canal sealer push-out bond strength (BS) to dentin and the sealer/dentin interface after different final irrigation solutions (NaOCl, EDTA, and chitosan). Sixty-four maxillary canines were distributed into two groups (n=30): non-irradiated and irradiated with 60 Gy. Canals were prepared with Reciproc-R50 and subdivided (n=10) for final irrigation (NaOCl, EDTA, chitosan) and filled.

Root canal preparation using micro-computed tomography analysis: a literature review.

This literature review has critically analyzed the published research related to the biomechanical preparation of root canals with three-dimensional analysis using micro-computed tomography (micro-CT). In December 2017, six databases (PubMed, Cochrane, Web of Science, Embase, Scopus, and Science Direct) were accessed using keywords to find articles including the use of the micro-CT analysis in biomechanical root canal preparation. There were 60 full articles that were selected, which were screened and read by two authors.

CAD/CAM diamond tool wear.

Objective: This study evaluated the wear of computer-aided design/computer-assisted manufacture (CAD/CAM) burs and the morphologic changes after a number of millings.

Method And Materials: Diamond burs (cylinder and step-bur) were divided into four milling groups: zero millings (G0); 15 millings (G1); 25 millings (G2); and 35 millings (G3). Seventy-five premolar crowns were milled using the Cerec Compact Milling unit and VitaBlock Mark II.

Effectiveness of different final irrigation techniques and placement of endodontic sealer into dentinal tubules.

The aim of this study was to compare two irrigation techniques and four devices for endodontic sealer placement into the dentinal tubules. Ninety-nine single-rooted human teeth were instrumented and allocated to either the control (CO) (n=11) or experimental groups according to the irrigation method: syringe and NaveTip needle (NT) (n=44), and EndoActivator (EA) (n=44). These groups were subdivided according to sealer placement into K-File (KF), lentulo spiral (LS), Easy Clean (EC), and EndoActivator (EA) subgroups.

Micro-CT Evaluation of Root and Canal Morphology of Mandibular First Premolars with Radicular Grooves.

The aim of this study was to evaluate morphological features of 70 single-rooted mandibular first premolars with radicular grooves (RG) using micro-CT technology. Teeth were scanned and evaluated regarding the morphology of the roots and root canals as well as length, depth and percentage frequency location of the RG. Volume, surface area and Structure Model Index (SMI) of the canals were measured for the full root length.

Are the bite force and electromyographic activity altered in muscle TMD patients with abfraction lesions?

Objective: To verify if the maximal molar bite force (BF) and the electromyographic activity (EMG) are altered in TMD patients with abfraction lesions (AL) when compared to those without AL.

Methods: The sample was composed of 45 patients (18-60 years old), 30 diagnosed with TMD (RDC/TMD) (15 with AL and 15 without AL) and 15 controls. The BF and the EMG of the masticatory muscles (maximal voluntary contraction (MVC) and chewing gum) were measured.

Effect of laser activated bleaching on the chemical stability and morphology of intracoronal dentin.

Objectives: To evaluate the effect of the bleaching with 35% hydrogen peroxide either activated or not by a 970nm diode laser on the chemical stability and dentin surface morphology of intracoronary dentin.

Methods: Twenty-seven slabs of intracoronary dentin specimens (3×3mm) were distributed into three groups (n=9), according to surface treatment: HP - 35% hydrogen peroxide (1×4'), DL - 970nm diode laser (1×30"/0,8W/10Hz), HP+DL - 35% HP activated with 970nm diode laser (1×30"/0,8W/10Hz leaving the gel in contact to the surface for 4' after activation). Three Raman spectra from each fragment were obtained to calculate the mean intensity of peaks of inorganic component (a.

Effect of different diode laser wavelengths on root dentin decontamination infected with Enterococcus faecalis.

The objective of this study was to evaluate the antibacterial effect and the ultrastructural alterations of diode laser with different wavelengths (808nm and 970nm) and its association with irrigating solutions (2.5% sodium hypochlorite and 2% chlorhexidine) in root dentin contaminated by a five days biofilm. Thirteen uniradicular teeth were sectioned into 100 dentin intraradicular blocks.

Efficacy of Different Cone-beam Computed Tomographic Protocols in the Identification of Mesiobuccal Canals of Maxillary First Molars: A Tomographic and Ex Vivo Study.

Introduction: Complementary methods of anatomic diagnosis, including cone-beam computed tomographic (CBCT) imaging, may be useful in the diagnosis of mesiobuccal (MB) canals of maxillary molars.

Methods: Thirty-five maxillary first molars were subjected to ex vivo analysis and 4 CBCT protocols: i-CAT Classic (Imaging Sciences International, Hatfield, PA) (ICC group), i-CAT Next Generation (Imaging Sciences International) (ICN group), PreXion 3D (PreXion, San Mateo, CA) (16.8-second acquisition time; PX1 group), and PreXion 3D (33.