Impacts of Contracted Endodontic Cavities on Primary Root Canal Curvature Parameters in Mandibular Molars.

Introduction: The purpose of this study was to provide information regarding the debate on contracted endodontic cavities (CECs); their impacts on angle, location, and radius of the primary canal curvature (PCC) were assessed in type IV mesial root canals of mandibular molars at different stages of instrumentation. Impacts on treatment time were also assessed.

Methods: Twenty-four teeth were matched by radiographic and micro-computed tomographic criteria and accessed via CECs (CEC, n = 12) or nonextended traditional endodontic cavities (TECs, n = 12).

Effect of access design on intracoronal bleaching of endodontically treated teeth: An ex vivo study.

Objectives: To determine the effect of access design on intracoronal bleaching with 35% carbamide peroxide on discolored teeth.

Materials And Methods: Forty-two intact maxillary central incisors were selected, sectioned and artificially stained using whole blood. Color measurements were performed with a spectrophotometer: before staining (T1), after staining (T2), at 7 (T3), and 14 (T4) days postbleaching.

Removal of calcium hydroxide from Weine Type II systems using photon-induced photoacoustic streaming, passive ultrasonic, and needle irrigation: a microcomputed tomography study.

Objective: This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars.

Material And Methods: Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.

Effect of Instrument Design and Access Outlines on the Removal of Root Canal Obturation Materials in Oval-shaped Canals.

Introduction: The aim of this study was to compare the effectiveness of TRUShape (TS) instruments with ProFile Vortex Blue (VB) instruments for the removal of obturation materials during retreatment of single-canal mandibular premolars performed through 2 access outlines.

Methods: Initial root canal treatment was completed through a contracted endodontic cavity (CEC) design. Canals were instrumented to an F2 ProTaper instrument, obturated with warm lateral condensation of gutta-percha with AH Plus sealer, and allowed to set for 30 days at 37°C and 100% humidity.

Interventions for treating traumatised ankylosed permanent front teeth.

Background: Teeth that have suffered trauma can fuse to the surrounding bone in a process called dental ankylosis. Ankylosed permanent front teeth fail to erupt during facial growth and can become displaced, thus resulting in functional and aesthetic problems. Dental ankylosis is also associated with root resorption, which may eventually lead to the loss of affected teeth.

Interventions for the management of external root resorption.

Background: External root resorption is a pathological process, which tends to occur following a wide range of mechanical or chemical stimuli such as infection, pressure, trauma or orthodontic tooth movement. Although it is predominantly detected by radiography, in some cases root resorption may be identified by clinical symptoms such as pain, swelling and mobility of the tooth. Treatment alternatives are case-dependent and aim to address the cause of the resorption and aid the regeneration of the resorptive lesion.

Micro-Computed Tomographic Evaluation of the Influence of Root Canal System Landmarks on Access Outline Forms and Canal Curvatures in Mandibular Molars.

Introduction: This study investigated the influence of anatomic root canal system landmarks on access outline forms of mandibular molars and correlated these to the theoretical distance of orifice relocation and changes in canal primary curvature.

Methods: Thirty relatively calcified human mandibular molars were selected and examined by micro-computed tomographic imaging. Three-dimensional volume reconstructions were made, root canal system landmarks identified, and plotted: canal orifices, canal position at the furcation level, and pulp horn location.

Influence of apical enlargement in cleaning and extrusion in canals with mild and moderate curvatures.

Optical microscopy and morphometric analysis were used in this study to evaluate, in vitro, the cleaning of the apical region in root canals with mild or moderate curvatures subjected to biomechanical preparation with a rotary system, as well as to assess the amount of extruded material to the periapical area. Lateral incisors (n = 32), 16 with curvature angles smaller or equal to 10º (GI) and 16 between 11º and 25º angles (GII) were submitted to Hero 642 rotary instrumentation with different surgical diameters: (A) 30.02 and (B) 45.

Influence of Hero Apical instruments on cleaning ovoid-shaped root canals.

The cleaning capacity of Hero 642 nickel-titanium files, complemented by the Hero Apical instruments in flattened roots, was determined by histological analysis, considering the area of action of the instruments on the coronal walls and the presence of remaining debris. Twenty-four single-canal, human mandibular incisors were divided into three groups and prepared as follows: GI, instrumented with Hero 642 NiTi files 30/.06, 25/.

Dentin permeability of the apical third in different groups of teeth.

This ex vivo study evaluated dentin permeability of the root canal in the apical third of different human groups of teeth. Eighty teeth were used, 8 from each dental group: maxillary and mandibular central incisors, lateral incisors and canines, maxillary first premolars (buccal and palatal roots), mandibular first premolars, and maxillary and mandibular second premolars, totalizing 88 roots that were distributed in 11 groups. The root canals were instrumented, irrigated with 1% NaOCl and 15% EDTA.

Interventions for the management of external root resorption.

Background: External root resorption is a pathological process which tends to occur following a wide range of mechanical or chemical stimuli such as infection, pressure, trauma or orthodontic tooth movement. Although it is predominantly detected by radiography, in some cases, root resorption may be identified by clinical symptoms i.e.

Ultra-structural changes at the apical stop irradiated with CO2 laser.

Objective: This study evaluated ultra-structural dentine changes at the apical stop after CO(2) laser irradiation used during biomechanical preparation.

Background: Most studies evaluating the sealing efficiency of CO(2) lasers have been carried out after apical root canal resections and retro-filling procedures.

Methods: Sixty human canines were prepared with #1 to #6 Largo burs.

Interventions for treating traumatised ankylosed permanent front teeth.

Background: Teeth that have suffered trauma can fuse to the surrounding bone - the process referred to as dental ankylosis. Ankylosed permanent front teeth fail to erupt during facial growth and can become displaced, thus resulting in functional and aesthetic problems. Dental ankylosis is also associated with root resorption, which eventually leads to the loss of affected teeth.

Permeability of different groups of maxillary teeth after 38% hydrogen peroxide internal bleaching.

This study evaluated the influence of internal tooth bleaching with 38% hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38% H2O2.

Antibacterial agents in composite restorations for the prevention of dental caries.

Background: Dental caries is a multifactorial disease in which the fermentation of food sugars by bacteria from the biofilm (dental plaque) leads to localised demineralisation of tooth surfaces, which may ultimately result in cavity formation. Resin composites are widely used in dentistry to restore teeth. These restorations can fail for a number of reasons, such as secondary caries, excessive wear, marginal degradation, tooth sensitivity, pulpal death, and restorative material fracture.

Ultrastructural evaluation of radicular dentin after Nd:YAG laser irradiation combined with different chemical substances.

This aticle sought to evaluate the dentin morphology after irradiation by a Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser, using different chemical substances to irrigate radicular canals: distilled water, 17% ethylenediaminetetraacetic acid plus Cetavlon (EDTAC), 1% sodium hypochlorite, and 2% chlorhexidine. Groups were subdivided according to the protocol of laser application (n=9). The specimens were analyzed by scanning electron microscopy (SEM).

Coronal resistance to fracture of endodontically treated teeth submitted to light-activated bleaching.

Objectives: The aim of this study was to assess the fracture resistance of endodontically treated teeth submitted to bleaching with 38% hydrogen peroxide activated by light-emitting diode (LED)-laser system.

Methods: Fifty maxillary incisors were endodontically treated, received a zinc phosphate barrier and were embedded in acrylic resin until cemento-enamel junction. The specimens were distributed into five groups (n=10) according to the number of bleaching sessions: GI, no treatment (control); GII, one session; GIII, two sessions; GIV, three sessions and GV, four sessions.

Effectiveness of root canal debris removal using passive ultrasound irrigation with chlorhexidine digluconate or sodium hypochlorite individually or in combination as irrigants.

Aim: The aim of this in vitro study was to evaluate the cleaning capacity of different auxiliary chemical substances energized with ultrasound in radicular dentin using morphologic analysis.

Methods And Materials: Twenty-eight single-canal, mandibular incisors were prepared with the Hero 642 canal preparation system following the sequence: 25/12, 30/06, 35/02, and 40/02, 1 mm from the apex. The specimens were then divided into four groups of seven teeth.

Ultrastructural analysis of root canal dentine irradiated with 980-nm diode laser energy at different parameters.

Objective: The purpose of this in vitro study was to investigate using the scanning electron microscope (SEM) the ultrastructural morphological changes of the radicular dentine surface after irradiation with 980-nm diode laser energy at different parameters and angles of incidence.

Background Data: There have been limited reports on the effects of diode laser irradiation at 980 nm on radicular dentin morphology.

Materials And Methods: Seventy-two maxillary canines were sectioned and roots were biomechanically prepared using K3 rotary instruments.

Effect of 980-nanometer diode laser on root canal permeability after dentin treatment with different chemical solutions.

This study evaluated the effect of 980-nm diode laser at different parameters on root canal dentin permeability associated with different irrigants. Seventy-five canines were sectioned at 15 mm from the apex, prepared mechanically up to #40 .02 instrument, and irrigated with 2 mL distilled water.

Temperature changes in the deciduous pulp chamber during cavity preparation with the Er:YAG laser.

Purpose: The purpose of this in vitro study was to evaluate the temperature changes in the pulp chambers of deciduous molars during cavity preparation with an Er:YAG (erbium substituted: yttrium aluminium garnet) laser.

Methods: Two cavities were prepared in 14 maxillary deciduous molars: one with the Er:YAG laser and other with a diamond bur using a high-speed handpiece (control), providing 4 groups with 7 cavities each. The laser treatment was applied for 30 seconds (group 1) and 60 seconds (group 3).

Oral undifferentiated high-grade pleomorphic sarcoma: report of a case.

The current World Health Organization classification considers the existence of an undifferentiated unclassifiable category of pleomorphic sarcomas, defined as a group of pleomorphic high-grade sarcomas. Undifferentiated high-grade pleomorphic sarcoma represents about 5% of all soft tissue sarcomas in adults and occurs more commonly in the extremities. In the oral cavity, undifferentiated pleomorphic sarcoma is extremely rare.

Influence of different endodontic filling materials on root fracture susceptibility.

Objective: To evaluate the influence of different endodontic materials on root fracture susceptibility.

Methods: Seventy-two mandibular incisors were sectioned 1mm below the cementoenamel junction to obtain roots of 12 mm length. Roots were submitted to chemomechanical preparation with the rotary instruments of Profile system.

Chemical analysis of the flocculate formed by the association of sodium hypochlorite and chlorhexidine.

Objective: The association of chlorhexidine (CHX) and sodium hypochlorite (NaOCl) to enhance their chemical properties during root canal biomechanical preparation can lead to a brown flocculate being formed. Therefore, this study evaluated the metals present in their association by atomic absorption spectrophotometry, and evaluated a possible reagent that could dissolve the flocculate, allowing its clinical use.

Study Design: Five concentrations of CHX and NaOCl were mixed (2.

Smear layer removal and chelated calcium ion quantification of three irrigating solutions.

The purpose of this study was to evaluate, by scanning electron microscopy (SEM), smear layer removal and quantify, by atomic absorption spectrophotometry, the amount of calcium ion present in the chelating solutions after their use. Sixteen extracted canines were instrumented using the step-back technique and were assigned to 3 groups according to the irrigating solution used: G1: 1 mL 17% EDTAC between each file; G2: 1 mL 17% CDTA; G3: 1 mL 17% EGTA. The solutions were collected after use.