Inferior alveolar nerve injury resulting from different implant rotary instruments: An ex vivo comparative study in human cadaveric mandibles.

The present study aimed to evaluate the degree of nerve injury on inferior alveolar nerve (IAN) by different implant drills resulting from direct canal intrusion into inferior alveolar canal (IAC). A cadaveric study involving 7 human mandibles was performed to evaluate mechanical injury of canal enclosed IAN resulting from different drills. In group 1, osteotomies were created using different drills with 1 mm of intracanal intrusion, simulating accidental drill intrusion into canal. In group 2, drilling was stopped when the tip has breached into IAC, limited by tactile feedback of operator. The depth and width of nerve defects were assessed using optical coherence tomography. A significant difference in defect depth was found (p < 0.001) in group 1. A sinus lift reamer inflicted the least damage (0.068 ± 0.022 mm). It was also found that the mean defect depth was significantly different when a twist drill was used (p = 0.016). Sinus lift reamer can be used safely for osteotomy preparation in mandible when bone height is limited or when radiographic visualization of canal is poor. Bone corticalization around IAC does not provide adequate protection for IAN in the event of accidental intracanal intrusion.

Cervicofacial and mediastinal emphysema following minor dental procedure: a case report and review of the literature.

BACKGROUND: Subcutaneous cervical emphysema is a clinical sign associated with many conditions, including laryngotracheal trauma, pneumothorax and necrotizing deep tissue infections. CASE PRESENTATION: We discuss a case of a 76-year-old man presenting with extensive cervical emphysema a few hours after a minor dental filling procedure. The CT-scan revealed a significant amount of air within the cervical and mediastinal spaces, reaching lobar bronchi. Vitals were within normal values Bloodwork demonstrated an elevation of creatinine kinase (3718; normal < 150) and mild leukocytosis (WBC = 11.6). We decided to proceed to an urgent cervical exploration to exclude necrotizing fasciitis. This revealed air but no tissue necrosis nor abnormal fluid. The patient improved clinically and was discharged two days later with oral antibiotics. Although cervicofacial subcutaneous emphysema following dental procedures has been reported, it is usually less extensive and involving more invasive procedures using air-driven handpieces. CONCLUSION: As an otolaryngologist confronted with extensive subcutaneous emphysema following a potential entry route for an aggressive infection, given the seriousness of this diagnosis, the decision of whether or not to perform a diagnostic surgical exploration should remain.

Factors influencing incidents of complications while using nickel-titanium rotary instruments for root canal treatment.

BACKGROUND: To investigate the complications associated with the use of nickel titanium rotary instruments (NiTi-RIs) for root canal treatments (RCTs), in Saudi Arabia dental practice, and to explore the influencing factors. METHODS: After obtaining an ethical approval, two pilot studies were conducted to formulate the final questionnaire. The sample size was measured taking into consideration 60% expected response rates and confidence level of 99.9%. The questionnaire was emailed to 600 general dentists (GDs) randomly selected from the dental register and all of the endodontists (175). The email's introduction clarified objectives of the study and guaranteed that all of the collected information would remain confidential. A reminder was sent after 10 weeks. The data were collected and analyzed using the chi-squared test at a 0.05 significance level. RESULTS: With a 51% overall response rate, 71.9% off the respondents used NiTi-RIs. The majority (83.1%) experienced complications while using NiTi-RIs; with the instruments' fracture being significantly the most common complication (52.7%) (p < 0.001). The majority (87.7%) experienced NiTi-RIs' fracture at least once; with more endodontists (94.3%) than GDs (83.3%) (p < 0.001). The greater the number of weekly performed RCTs and participants' experiences, the more NiTi-RIs fractures and the greater the number of fracture incidents (p < 0.001). While 60% of those who performed 1-3 RCTs per week experienced NiTi-RIs fractures, 100% of those who performed more than 12 RCTs per week did so. The highest percentage of those who experienced more than 10 fractured NiTi-RIs (60%) was within the group who performed more than 12 RCTs per week. Although fracture incidents decreased with a smaller number of reuses, there was no significant correlation between the number of fractured instruments and NiTi-RIs discard strategy (p ≥ 0.05). CONCLUSION: Fracture incidence was the most common complication while using NiTi-RIs, regardless of the clinicians' experiences and skills. While the single use may reduce NiTi-RIs fractures, to some extent, the greater number of RCTs performed per week was the most influential factor.

Heat Production and Drill Wear Following Osseous Resective Surgery: A Preliminary In Vitro SEM Study Comparing Piezosurgery and Conventional Drilling.

The aim of this pilot in vitro study was to evaluate material wear and temperature variations after using conventional rotating bur and piezosurgical insert for osseous resective surgery in bovine bone blocks under physiologic irrigation. Wear evaluation was carried out by measuring cutting time, and wear mechanisms were analyzed by scanning electron microscopy. Time analysis showed greater material wear and higher heat production with the piezoelectric insert. However, temperatures remained below values of clinical concern even after a cutting time of 20 minutes. Conversely, bone surface appeared irregular in shape with bone debris and signs of thermal damage on the bur-drilled surface, probably due to the more traumatic action of the diamond-coated bur.

Comparative Evaluation of Stress Distribution in Experimentally Designed Nickel-titanium Rotary Files with Varying Cross Sections: A Finite Element Analysis.

INTRODUCTION: Single cross-sectional nickel-titanium (NiTi) rotary instruments during continuous rotations are subjected to constant and variable stresses depending on the canal anatomy. This study was intended to create 2 new experimental, theoretic single-file designs with combinations of triple U (TU), triangle (TR), and convex triangle (CT) cross sections and to compare their bending stresses in simulated root canals with a single cross-sectional instrument using finite element analysis. METHODS: A 3-dimensional model of the simulated root canal with 45° curvature and NiTi files with 5 cross-sectional designs were created using Pro/ENGINEER Wildfire 4.0 software (PTC Inc, Needham, MA) and ANSYS software (version 17; ANSYS, Inc, Canonsburg, PA) for finite element analysis. The NiTi files of 3 groups had single cross-sectional shapes of CT, TR, and TU designs, and 2 experimental groups had a CT, TR, and TU (CTU) design and a TU, TR, and CT (UTC) design. The file was rotated in simulated root canals to analyze the bending stress, and the von Mises stress value for every file was recorded in MPa. Statistical analysis was performed using the Kruskal-Wallis test and the Bonferroni-adjusted Mann-Whitney test for multiple pair-wise comparison with a P value <.05 (95 %). RESULTS: The maximum bending stress of the rotary file was observed in the apical third of the CT design, whereas comparatively less stress was recorded in the CTU design. The TU and TR designs showed a similar stress pattern at the curvature, whereas the UTC design showed greater stress in the apical and middle thirds of the file in curved canals. All the file designs showed a statistically significant difference. CONCLUSIONS: The CTU designed instruments showed the least bending stress on a 45° angulated simulated root canal when compared with all the other tested designs.

Cyclic Fatigue Resistance of Heat-treated Nickel-titanium Instruments after Immersion in Sodium Hypochlorite and/or Sterilization.

INTRODUCTION: The purpose of this study was to assess the effects of sodium hypochlorite (NaOCl) immersion and sterilization on the cyclic fatigue resistance of heat-treated nickel-titanium (NiTi) rotary instruments. METHODS: Two hundred ten new 25/.06 Twisted Files (TFs; SybronEndo, Orange, CA) and Hyflex CM (Coltene Whaledent, Cuyahoga Falls, OH) files were divided into 7 groups (n = 15) for each brand. Group 1 (control group) included new instruments that were not immersed in NaOCl or subjected to autoclave sterilization. Groups 2 and 3 were composed of instruments dynamically immersed for 3 minutes in 5% NaOCl solution 1 and 3 times, respectively. Groups 4 and 5 consisted of instruments only autoclaved 1 and 3 times, respectively. Groups 6 and 7 recruited instruments that received a cycle of both immersion in NaOCl and sterilization 1 and 3 times, respectively. Instruments were subsequently subjected to a fatigue test. The surface morphology of fractured instruments was studied by field-emission scanning electron microscopy and x-ray energy-dispersive spectrometric (EDS) analyses. The means and standard deviations of the number of cycles to failure (NCF) were calculated and statistically analyzed using 2-way analysis of variance (P < .05). RESULTS: Comparison among groups indicated no significant difference of NCF (P > .05) except for the groups of TFs sterilized 3 times without and with immersion in NaOCl (P < .05). HyFlex CM files exhibited higher cyclic fatigue resistance than TFs when files were sterilized 3 times, independently from immersion in NaOCl (P < .05). EDS analysis showed the presence of an oxide-rich layer on the Hyflex CM files' external surface. No morphologic or chemical differences were found between files of the same brand subjected to different treatments. CONCLUSIONS: Repeated cycles of sterilization did not influence the cyclic fatigue of NiTi files except for TFs, which showed a significant decrease of flexural resistance after 3 cycles of sterilization. Immersion in NaOCl did not reduce significantly the cyclic fatigue resistance of all heat-treated NiTi files tested.

Low Environmental Temperature Influences the Fatigue Resistance of Nickel-titanium Files.

INTRODUCTION: The purpose of this study was to evaluate the effect of different temperatures (0°C, 10°C, 22°C, 37°C, and 60°C) on the cyclic fatigue life of nickel-titanium (NiTi) files using a new fatigue test model in zirconium oxide. METHODS: Three superelastic NiTi files (EndoSequence [Brasseler USA, Savannah, GA], ProFile [Dentsply Tulsa Dental Specialties, Tulsa, OK], and K3 [SybronEndo, Orange, CA]), and 3 heat-treated (K3XF [SybronEndo], Vortex [Dentsply Tulsa Dental Specialties], and HyFlex CM [Coltene-Whaledent, Allstetten, Switzerland]) NiTi files, all size 25/.04, were subjected to cyclic fatigue tests inside a novel, artificial ceramic canal with a curvature of 60° and a 5-mm radius. The model was immersed in water at 5 different preset temperatures. The number of cycles to failure (NCF) was recorded, and the fracture surface of the fragments was examined by a scanning electron microscope. The data were analyzed using 2-way analysis of variance with the significance level at 0.05. RESULTS: When the temperature was reduced from 60°C to 0°C, the NCF significantly increased from over 2 to 10 times for the NiTi file groups (P < .01). K3XF had the highest fatigue resistance of all files at 0°C (P < .05). Vortex files had the highest NCF at 10°C-60°C. The NCF of heat-treated files was significantly higher than superelastic NiTi files at 10°C and 20°C (P < .05). There was no significant difference in the NCF of HyFlex CM at 0°C and 22°C. There was little difference in the fractographic appearance among different temperatures, except that the fraction area occupied by the dimple region of some instruments at 0°C was slightly smaller than at 60°C. CONCLUSIONS: Cooling down to low temperatures may be an interesting strategy to improve the fatigue resistance of rotary NiTi files.

Debris extrusion and foraminal deformation produced by reciprocating instruments made of thermally treated NiTi wires

Abstract Objective To evaluate the amount of apically extruded debris, percentage of foraminal enlargement and apical foramen (AF) deformation that occurred during root canal preparation with different reciprocation systems: Reciproc, WaveOne (M-Wire), and ProDesign R (Shape Memory Technology Wire) at two different working lengths (WLs): 0.0 and 1.0 mm beyond the AF. Material and methods The AF of 120 root canals in 60 mesial roots of mandibular molars were photographed with stereomicroscope and randomly assigned into four groups: manual, Reciproc (REC), WaveOne (WO), and ProDesign R (PDR); subsequently, they were further subdivided according to the WL (n=15). Teeth were instrumented, coupled to a dual collecting chamber, and then another photograph of each AF was captured. Extrusion was analysed by determining the weight of extruded debris. Each AF diameter was measured in pre- and post-instrumentation images to determine deformation, which was analysed, and afterwards the final format of AFs was classified (circular/oval/deformed). Results We found no significant differences when analysing each system at different WLs. When considering each WL, REC and WO showed highest extrusion values (P<.05); for AF enlargement, differences were observed only for WO, when it was used beyond the AF; differences were observed among M-Wire groups beyond the AF (P<.05). AF deformation was observed in all groups; PDR showed the lowest AF deformation values at both WLs; M-Wire groups showed 50% strain beyond the AF. Conclusion Authors concluded that beyond the apical limit, the alloy and taper are important aspects when considering extrusion and deformation.

Fatigue Resistance of Nickel-titanium Instruments Exposed to High-concentration Hypochlorite.

INTRODUCTION: The purpose of this study was to introduce a new fatigue test model that simulates the clinical situation for evaluating the corrosion effect of 5.25% sodium hypochlorite (NaOCl) on nickel-titanium (NiTi) files and to evaluate the effect of 3 different temperatures (22°C, 37°C, and 60°C) on the cyclic fatigue of these files. METHODS: Three NiTi files (size 25/.04), K3 (SybronEndo, Orange, CA), K3XF (SybronEndo), and Vortex (Dentsply Tulsa Dental Specialties, Tulsa, OK), were subjected to cyclic fatigue tests inside a novel artificial ceramic canal with a curvature of 60° and a 5-mm radius. A 19-mm-long file segment from the tip was introduced into the canal and immersed in water or 5.25% NaOCl at 3 different temperatures, and the number of revolutions to fracture (Nf) was recorded. The fracture surface of all fragments was examined by a scanning electron microscope. Data were analyzed using univariate analysis of variance with the significance level at 0.05. RESULTS: The Nf of Vortex files was the highest followed by K3XF and K3 (P < .05) at all conditions. The Nf of all files was highest at 22°C and lowest at 60°C (P < .05). However, no difference in Nf was detected in Vortex files between 22°C and 37°C. The Nf of all files in 5.25% NaOCl was shorter than that in water although there was no statistically significant difference. No pitting or crevice corrosion was observed on the fracture surface. CONCLUSIONS: NaOCl, 5.25%, does not significantly affect the fatigue behavior of NiTi files. The fatigue resistance should be tested under specific temperature conditions. The austenite finish temperature of a file is important in determining the fracture risk at body temperature.

Displacement of a Broken Dental Injection Needle Into the Perivertebral Space.

Dental injection needle breakage is an uncommon problem in dental practice. Displacement of the broken fragment into anatomical spaces is, on the other hand, a serious complication that occurs most commonly during inferior alveolar nerve blocks as a result of material wear, incorrect application of the anesthesia technique, or sudden movement of the patient during injection. Further complications such as infection, trismus, and nerve paralysis may exacerbate the condition and, if not treated adequately, life-threatening conditions may develop over time as the fragment dislodges deeper in soft tissues. Clinical symptoms of the patient, as well as the findings gathered from detailed physical examination and radiographic evaluation, are important factors to consider before performing an exploratory surgery. Removal of a broken needle may be troublesome due to its proximity to vital anatomic structures. Multislice computed tomography is a reliable imaging modality that provides accurate information to pinpoint the exact location of the needle fragment.This report describes a case of needle breakage occurred during inferior alveolar nerve block which was performed to extract a third molar tooth and the migration of the broken fragment from the right mandibular ramus area into the perivertebral space, with special emphasis on the surgical retrieval technique with multiplanar computed tomography imaging guidance.

Postoperative pain intensity after using different instrumentation techniques: a randomized clinical study

Abstract Postoperative pain is a frequent complication associated with root canal treatment, especially during apical instrumentation of tooth with preexisting periradicular inflammation Objectives The aim of this clinical study was to evaluate the influence of the instrumentation techniques on the incidence and intensity of postoperative pain in single-visit root canal treatment. Material and Methods Ninety patients with single root/canal and non-vital pulps were included. The patients were assigned into 3 groups according to root canal instrumentation technique used; modified step-back, reciprocal, and rotational techniques. Root canal treatment was carried out in a single visit and the severity of postoperative pain was assessed via 4-point pain intensity scale. All the participants were called through the phone at 12, 24 and 48 h to obtain the pain scores. Data were analyzed through the Kruskal–Wallis test. Results There was significant difference between all groups (p<0.05). The modified step-back technique produced postoperative pain significantly lower than the rotational (p=0.018) and reciprocal (p=0.020) techniques. No difference was found between the reciprocal and rotational techniques (p=0.868). Postoperative pain in the first 12 h period (p=0.763) and in the 24 h period (p=0.147) was not significantly different between the groups. However, the difference in the 48 h period was statistically different between the groups (p=0.040). Conclusion All instrumentation techniques caused postoperative pain. The modified step-back technique produced less pain compared to the rotational and reciprocal techniques.

Use of an intraoperative navigation system for retrieving a broken dental instrument in the mandible: a case report.

BACKGROUND: A fracture of root canal instruments, with a fractured piece protruding beyond the apex, is a troublesome incident during an endodontic treatment. Locating and retrieving them represents a challenge to maxillofacial surgeons because it is difficult to access due to the proximity between the foreign body and vital structures. Although safe and accurate for surgery, radiographs and electromagnetic devices do not provide a precise three-dimensional position. In contrast, computer-aided navigation provides a correlation between preoperatively collected data and intraoperatively encountered anatomy. However, using a navigation system for mandible treatment is difficult as the mobile nature of the mandible complicates its synchronization with the preoperative imaging data during surgery. CASE PRESENTATION: This report describes a case of a dental instrument breakage in the mandible during an endodontic treatment for a restorative dental procedure in a 65-year-old Japanese woman. The broken dental instrument was removed using a minimally invasive approach with a surgical navigation system and an interocclusal splint for a stable, identically repeatable positioning of the mandible. Using the three-dimensional position of the navigation probe, a location that best approximated the most anterior extent of the fragment was selected. A minimally invasive vestibular incision was made at this location, a subperiosteal reflection was performed, and the foreign body location was confirmed using a careful navigation system. The instrument was carefully visualized and extruded from the apical to the tooth crown side and was then removed using mosquito forceps through the medullary cavity of the crown side of the tooth. Follow-up was uneventful; her clinical course was good. CONCLUSIONS: The use of a surgical navigation system together with an interocclusal splint enabled the retrieval of a broken dental instrument in a safe and minimally invasive manner without damaging the surrounding vital structures.

Fracture resistance of dental nickel-titanium rotary instruments with novel surface treatment: Thin film metallic glass coating.

BACKGROUND/PURPOSE: Dental nickel-titanium (NiTi) rotary instruments are widely used in endodontic therapy because they are efficient with a higher success rate. However, an unpredictable fracture of instruments may happen due to the surface characteristics of imperfection (or irregularity). This study assessed whether a novel surface treatment could increase fatigue fracture resistance of dental NiTi rotary instruments. METHODS: A 200- or 500-nm thick Ti-zirconium-boron (Ti-Zr-B) thin film metallic glass was deposited on ProTaper Universal F2 files using a physical vapor deposition process. The characteristics of coating were analyzed by scanning electron microscopy, transmission electron microscopy, and X-ray diffractometry. In cyclic fatigue tests, the files were performed in a simulated root canal (radius=5 mm, angulation=60°) under a rotating speed of 300rpm. The fatigue fractured cross sections of the files were analyzed with their fractographic performances through scanning electron microscopy images. RESULTS: The amorphous structure of the Ti-Zr-B coating was confirmed by transmission electron microscopy and X-ray diffractometry. The surface of treated files presented smooth morphologies without grinding irregularity. For the 200- and 500-nm surface treatment groups, the coated files exhibited higher resistance of cyclic fatigue than untreated files. In fractographic analysis, treated files showed significantly larger crack-initiation zone; however, no significant differences in the areas of fatigue propagation and catastrophic fracture were found compared to untreated files. CONCLUSION: The novel surface treatment of Ti-Zr-B thin film metallic glass on dental NiTi rotary files can effectively improve the fatigue fracture resistance by offering a smooth coated surface with amorphous microstructure.

Electrochemical dissolution of fractured nickel-titanium instruments in human extracted teeth.

AIM: To assess the effect of sodium chloride concentration in fluoridated solutions during the electrochemical dissolution of fractured rotary endodontic instruments. METHODOLOGY: Two solutions were assessed (solution 1: NaF 12 g L-1  + NaCl 1 g L-1 , pH = 5.0; and solution 2: NaF 12 g L-1  + NaCl 180 g L-1 , pH = 5.0) using two tests: the ProTaper Universal F1 (PTU F1) instrument polarization test and the polarization test for intracanal PTU F1 fragments fractured in mandibular incisors. In the first test, two sets of five instruments were separately and partially immersed in each solution, and the electrical current was evaluated over 30 min. In the second test, 45 PTU F1 instruments were fractured within the root canals of mandibular incisors and subjected to potentiodynamic polarization for 30 min. The electrical current and the variations in the length of PTU F1 fragments were measured. The data were analysed statistically (anova and Wilcoxon and Mann-Whitney tests, respectively). RESULTS: Solution 2 was associated with more corrosive effects in both tests. In the first test, the PTU F1 instruments immersed in solution 2 had a higher electrical current (P < 0.001) and had a total dissolution time of approximately 540 s. In the second test, a larger difference between the baseline and final lengths of the fragments was noted in solution 2 (P = 0.011). CONCLUSION: Saturation of fluoridated solution with sodium chloride led to an increase in electrical current and microscopic reductions in the length of fractured instrument fragments subjected to electrochemical dissolution.

Drill-related root injury caused by intraoperative intermaxillary fixation: an analysis of 1067 screw applications.

BACKGROUND/AIMS: Intermaxillary fixation is a standard procedure for the treatment of mandibular fractures or in orthognathic surgery. Predrilling for screws poses the risk of accidental tooth root injury, potentially leading to further pathological processes. Limited evidence about accidental tooth injury during intermaxillary fixation is available due to heterogenous study designs. The aim of this study was to evaluate the risk of root trauma using predrilled transgingival fixation screws and the clinical consequences for the affected teeth. MATERIALS AND METHODS: In this retrospective study, the data of open reduction and internal fixation surgery files with intraoperative application of predrilled intermaxillary fixation screws were analysed. The postoperative radiographic images were evaluated for the occurrence of tooth root injury. Patients diagnosed with root injury were clinically followed up with respect to the dental health for the affected teeth. RESULTS: A total of 133 radiologically diagnosed tooth root injuries were recorded (12.5% of screws). The median follow-up interval was 16 months (range: 3-77 months). The return rate was 49.5% for all patients. Of these, four of the injured teeth (3%) needed endodontic treatment. No toothache was reported, no tooth was lost, and no negative impact on periodontal health was clinically evident. CONCLUSION: Intermaxillary fixation with predrilled transgingival screws is a safe way to manage mandibular fractures. The incidence of tooth root injury is not uncommon, but the adverse side effects are rare and the health of the affected teeth is mostly not compromised.

Evaluation of Two Trephine Techniques for Removal of Fractured Rotary Nickel-titanium Instruments from Root Canals.

INTRODUCTION: The aim of this in vitro study was to evaluate the effects on root dentin of 2 trephining techniques using an ultrasonic tip or a trepan bur in the mesial canals of mandibular molars during attempts to remove fractured file fragments using micro-computed tomographic imaging. METHODS: Twenty-one teeth with a similar anatomic configuration in mesial (buccal and lingual) canals were selected. A 4-mm apical segment of K3 file size 25/.06 was fractured in each mesiobuccal and mesiolingual canal 5 mm apically from the canal orifice. A staging platform was prepared at the coronal aspect of the broken instrument followed by either ultrasonics or a new trepan bur technique to expose a 1- to 1.5-mm length of the fragment. If the broken instrument could not be removed by exposing it either by ultrasound or the trepan bur, a microtube device was used to attach to and withdraw the fragment. Micro-CT scanning was performed before and after removing the broken instrument. Canal volume, diameter, and furcal root dentin thickness were measured by using image analysis software. The time required for the removal of the instrument fragments was recorded. The result was statistically analyzed using the paired t test. RESULTS: The trepan bur technique had significantly less impact on canal volume, diameter, and furcal root dentin thickness change than the ultrasonic technique (P < .001). The time consumed for successful removal of the fragments was significantly less in the trepan bur group (8.9 ± 3.5 minutes) than in the ultrasonic group (25 ± 11.9 minutes) (P < .001). CONCLUSIONS: A new small-sized trepan bur technique was superior to the use of ultrasound with regard to the amount of dentin removed and the speed in the removal of fractured instruments from root canals.

Evaluación de la portación de cándida spp en pinzas ortodóncicas post utilización / Evaluation of candida spp carriage on orthodontic pliers, after using them

Objetivo: evaluar el nivel de contaminación por Candida spp, post uso del instrumental de ortodoncia que se utiliza intrabucalmente en pacientesColombianos y Argentinos. Materiales y métodos: Se incluyeron pacientesentre 16 y 65 años, de ambos sexos, con armado de brackets superior e inferior. Criterios de Exclusión: pacientes con brackets de autoligado, con enfermedades autoinmunes, con enfermedades sistémicas con manifestaciones en el periodonto, pacientes fumadores, menores de 16 años y con armado de brackets en un solo maxilar. Se analizaron los alicates de corte distal Hu Friedy luego de ser utilizados para seccionar el arco por distal del último tubo presente enboca. Se estudiaron 80 pacientes agrupados en: Grupo A 40 pacientesColombianos, Grupo B 40 pacientes argentinos. Se realizó una primer tomaintrabucal con un hisopo estéril y se llevó a un tubo con medio de Stuart. Se cortaron las 4 secciones distales de los arcos en boca tardando al menos 1 minuto. Con un segundo hisopo estéril se frota toda la superficie del alicate post uso y se llevaron a otro tubo. Se sembraron en Chromagar Candida y se realizaron pruebas microbiológicas convencionales. Resultados: Las pinzas estériles aparecen contaminadas post corte distal delos alambres en el 95% de los casos en ambos países. Hubo diferencia entrelos pacientes colombianos y los argentinos respecto a las especies, ya que enlos primeros la especie con mayor prevalencia fue Candida tropicalis tanto en lapinza como en la cavidad bucal, mientras que en los argentinos fue Candidaalbicans. Conclusión: las pinzas de ortodoncias se contaminan con Candidaspp post utilización en boca y son un fómite a partir del cual puede generarsediseminación sistémica así como infección cruzada.

The effect of various kinematics on postoperative pain after instrumentation: a prospective, randomized clinical study

ABSTRACT Objective: To evaluate various kinematic movements on postoperative pain using a Reciproc system. Material and Methods: Fifty-six molar teeth were divided into four groups according to kinematics as follows: continuous rotation, 360° CCW – 30° CW, 270° CCW – 30° CW, and 150° CCW – 30° CW. Preoperative and postoperative pain levels using visual analogue scale (VAS), percussion pain, and analgesic intake were recorded for each subject. Postoperative pain levels at 1, 3, 5, and 7 d were evaluated. Data were analyzed statistically using the Kruskal-Walis, Mann-Whitney-U, one-way analysis of variance, and chi-square tests (p=0.05). Results: Continuous rotation resulted in more pain at Day 1 when compared with the reciprocating groups (360° CCW – 30° CW and 270° CCW – 30° C) (p<0.05). Conclusions: Continuous rotation resulted in more postoperative pain at Day 1 than in reciprocating groups, and thereafter no significant pain was found among the groups.