Capacidad de sellado apical entre dos técnicas de obturación con instrumentos rotatorios fracturados en tercio apical / Apical sealing capacity between two obturation techniques with rotary instruments broken in third apical

Introducción: La finalidad del tratamiento de conductos es conseguir la máxima desinfección, conformación y sellado tridimensional. Objetivo: Comparar la capacidad del sellado apical entre dos técnicas de obturación en conductos mesiales de molares inferiores con limas fracturadas en tercio apical. Material y métodos: Se utilizaron 60 raíces mesiales de molares inferiores, instrumentados con Protaper Universal, se desgastó 4 milímetros la parte activa del instrumento y se fracturó intencionalmente en tercio apical. Se formaron dos grupos de 30 raíces mesiales (n = 30) cada uno y se utilizaron dos técnicas de obturación: grupo 1: condensación lateral clásica y grupo 2: Obtura II. Las muestras se sumergieron en tubos de ensayo y en su interior contenían 5 mL de tinta china, se diafanizaron y observaron con un microscopio estereoscópico (LEICA, EZ4D) a 35x para medir la penetración de tinta china dentro del conducto radicular. Resultados: Se encontró una mayor microfiltración apical con suficiente evidencia estadística en el grupo de Obtura II comparado con el grupo de condensación lateral clásica (p < 0.002). Conclusiones: Ambos grupos presentaron microfiltración apical; sin embargo, en el grupo que se utilizó el sistema de obturación termoplastificada Obtura II se detectó mayor filtración apical comparada con el grupo de condensación lateral clásica (AU)

Introduction: The purpose of root canal treatment is to achieve maximum disinfection, shaping and three-dimensional sealing. Objective: To compare the apical sealing capacity between two obturation techniques in mesial canals of mandibular molars with broken files in the apical third. Material and methods: 60 mesial roots of lower molars were used, instrumented with Protaper Universal, the active part of the instrument was worn by 4 millimeters and it was intentionally broken in the apical third. Two groups of 30 mesial roots (n = 30) each were formed and two filling techniques were used: group 1: classic lateral condensation and group 2: Obtura II. The samples were immersed in test tubes and contained 5 mL of Chinese ink inside, they were clear and observed with a stereomicroscope (LEICA, EZ4D) at 35x to measure the penetration of Chinese ink into the root canal. Results: A higher apical microfiltration with sufficient statistical evidence was found in the Obtura II group compared to the classic lateral condensation group (p < 0.002). Conclusions: Both groups presented apical microfiltration, however, in the group that used the Obtura II thermoplastic obturation system, greater apical filtration was detected compared to the classic lateral condensation group (AU)

Water jet as a novel technique for enamel drilling ex vivo.

To investigate the usage of a water jet for enamel drilling ex vivo, 210 individual extracted molars without lesions or fillings were collected. Then, the specimens were drilled by a water jet or a high-speed dental drill. The cavities of 50 teeth were reconstructed digitally by micro-computed tomography (micro-CT) to measure the height and width. The cavities of 10 teeth were longitudinally incised and their surfaces were observed by scanning electronic microscopy (SEM). After the cavities were filled, 50 fillings were vertically incised. The bonding interface between tooth and filling was observed by SEM. 50 teeth with fillings were stained in 0.1% rhodamine B solution, and then the dye penetration between tooth and filling was observed under the stereomicroscope and confocal laser scanning microscopy (CLSM). The bonding strength between enamel and filling of 50 teeth was simulated and predicted with finite element analysis (FEA). At 140-150 MPa and for 2-3 s, cavities were made with a depth of approximately 764 µm in each tooth. SEM showed the cavity surface in the water jet group had a more irregular concave and convex structure than that in the high-speed dental drill group. There was a trend that the microleakage and bonding width was smaller in the water jet group than in the high-speed dental drill group. FEA indicated that the stress on the resin surface was greater than on the enamel surface in the water jet group. Compared with the tooth drilled by a high-speed dental drill, the tooth drilled by a water jet gained better retention of the filling material and suffered less bonding strength on the enamel surface. Water jet drilling is effective for enamel drilling.

Actualización acerca del riesgo de pérdida auditiva inducida por ruido en el personal odontológico / Upgrade about the risk of hearing loss in the dental personal

La relación entre la exposición a los ruidos y la pérdida auditiva se considera desde hace muchos años. La comunidad odontológica no está exenta de este problema, ya que los profesionales trabajan a diario, y durante tiempos prolongados, con instrumentos ruidosos. Esta revisión bibliográfica tiene como propósito realizar una actualización acerca del riesgo de pérdida auditiva inducida por ruido en el personal que trabaja en la clínica odontológica. En la actualidad, se afirma que los odontólogos y el personal en la clínica dental corren el riesgo de contraer diversas patologías auditivas ­como es el caso de la hipoacusia­ debido al ruido que producen los equipos de alta velocidad. Las enfermedades profesionales del tipo auditivas que se abordan en este trabajo constituyen factores que comprometen no solo el buen estado de salud de los odontólogos y demás profesionales, sino su calidad de vida (AU)

The relationship between noise exposure and hearing loss has been known for many years. The dental community is not exempt from this problem, because they work every day and for long periods of time with noisy instruments. This literature review aims to update the risk of noise-induced hearing loss in personnel working in the dental clinic. The risk to which dentists and staff in the dental clinic are subjected to the high-speed and other noisy equipment is well known, and that can cause various auditory problems such as hearing loss. The occupational diseases of the auditory type that were addressed in this article constitute factors that compromise not only the good state of health of dentists and other professionals who work in similar conditions, but also in their quality of life (AU)

Iatrogenic subcutaneous facial emphysema secondary to a Class V dental restoration: a case report.

Subcutaneous facial emphysema (SFE) following routine dental operative procedure is an uncommon but potentially life-threatening complication. The present case details a Class V restoration where air was introduced into the fascial tissue planes via the gingival sulcus from the use of an air-driven dental handpiece. Although the SFE is usually self-limiting within 3-10 days, such instances should be regarded as a medical emergency as in severe cases, the air may spread to the neck, mediastinum and thorax to result in cervicofacial emphysema with potential pneumomediastinum and pneumothorax.

Sudden Onset of Subcutaneous Air Emphysema After the Application of Air to a Maxillary Premolar Located in a Nonsurgical Field.

Although rare, subcutaneous air emphysema can occur during dental procedures such as endodontic treatment, surgical extractions, and preparing a tooth for an indirect or direct dental restoration. We report the development of a subcutaneous air emphysema that was introduced through the periodontal ligament of an untreated premolar after the use of an air syringe to dry the tooth.

Subcutaneous emphysema secondary to dental extraction: A case report.

Although less frequently encountered in dental practices, subcutaneous emphysema of the face and neck has been reported in patients following dental extractions, particularly when lower molar teeth are extracted with the use of a high-speed air-turbine drill designed for restorative treatment, which forces air into the cervical fascial spaces. As facial swelling and pain are the most common presentations, subcutaneous emphysema can often be misdiagnosed as an allergic reaction or odontogenic infection. While usually a benign and self-limiting condition, subcutaneous emphysema may have life-threatening complications such as tension pneumothorax, cardiac tamponade, air embolism, tracheal compression and mediastinitis, which are important to recognize in an emergency setting. Dentists should be aware of the serious risks of inducing subcutaneous emphysema and avoid performing tooth extractions with high-speed air-turbine drills which are specifically designed for use for restorative treatments only.

Statistical Analysis for Subjective and Objective Evaluations of Dental Drill Sounds.

The sound produced by a dental air turbine handpiece (dental drill) can markedly influence the sound environment in a dental clinic. Indeed, many patients report that the sound of a dental drill elicits an unpleasant feeling. Although several manufacturers have attempted to reduce the sound pressure levels produced by dental drills during idling based on ISO 14457, the sound emitted by such drills under active drilling conditions may negatively influence the dental clinic sound environment. The physical metrics related to the unpleasant impressions associated with dental drill sounds have not been determined. In the present study, psychological measurements of dental drill sounds were conducted with the aim of facilitating improvement of the sound environment at dental clinics. Specifically, we examined the impressions elicited by the sounds of 12 types of dental drills in idling and drilling conditions using a semantic differential. The analysis revealed that the impressions of dental drill sounds varied considerably between idling and drilling conditions and among the examined drills. This finding suggests that measuring the sound of a dental drill in idling conditions alone may be insufficient for evaluating the effects of the sound. We related the results of the psychological evaluations to those of measurements of the physical metrics of equivalent continuous A-weighted sound pressure levels (LAeq) and sharpness. Factor analysis indicated that impressions of the dental drill sounds consisted of two factors: "metallic and unpleasant" and "powerful". LAeq had a strong relationship with "powerful impression", calculated sharpness was positively related to "metallic impression", and "unpleasant impression" was predicted by the combination of both LAeq and calculated sharpness. The present analyses indicate that, in addition to a reduction in sound pressure level, refining the frequency components of dental drill sounds is important for creating a comfortable sound environment in dental clinics.

Hearing loss associated with long-term exposure to high-speed dental handpieces.

The purpose of this study was to record and compare audiometric pure tone thresholds of dental clinicians (DCs), dental professionals (DPs), and dental students (DSs); determine the percentage of these groups who use hearing protection devices while at work in the clinic; and measure the sound intensities generated by a few representative high-speed handpieces while they are being used on patients. Participants included DCs who regularly used these handpieces (n = 16), DPs who did not use these handpieces (n = 13), and DSs (n = 8). A questionnaire was used to collect demographic information, assess occupational and recreational noise exposure, and note the level of hearing protection used. A sound level meter was used to measure the sound intensity generated by dental instruments near a clinician's ear. Results showed that DCs who regularly used high-speed handpieces had worse hearing than did members of the other study groups. These results indicate that the implementation of protective strategies should help to reduce the prevalence of occupational hearing loss among DCs.

Operator's ability at assessing a high-speed (air turbine) handpiece before use: an audit.

BACKGROUND: The 'high-speed' (air turbine) handpiece is used extensively across many dental disciplines and the ability of clinicians to detect faulty handpieces is essential. AIM: The primary aim of this audit was to determine the proportion of participants who could correctly identify unsafe handpieces. Secondary aims were to determine the proportion that had previous training on the topic and determine whether an educational video could improve scores. METHOD: Eighty participants completed the first round of audit. They were asked to inspect seven handpieces, five of which were faulty, with three being classed as unsafe. After the intervention (educational sessions and distribution of a video) a second round of audit was completed on 69 participants. RESULTS: The ability to detect the three unsafe handpieces increased from 10% to 44% over the two rounds of audit. In the second round the highest score obtained was by those who had received the intervention, 77%. The lowest score, 14%, was by those who had not received the intervention. Nine percent of participants in the first round stated they had previously had training on handpiece inspection and none of these participants identified the three unsafe handpieces. CONCLUSION: This audit has highlighted that there is a knowledge deficiency with regards to air turbine handpiece safety and inspection. We have shown that introduction of a simple education video can have an impact on dentists and students abilities to detect unsafe faults. We have already introduced this into the undergraduate curriculum in our school and we aim to also raise awareness within the dental community.

Evaluation and prevention of enamel surface damage during dental restorative procedures.

BACKGROUND: This study examined the effect of operator experience, dominance, tooth position and access, on frequency and extent of iatrogenic damage to approximal tooth surfaces during conventional Class II cavity preparations. The effectiveness of protective devices in minimizing damage was also explored. METHODS: 10 students and 10 experienced dentists each prepared 24 Class II cavity preparations in typodont teeth without protection; 10 utilizing stainless steel matrix bands and 10 utilizing protective wedges. The frequency and extent of damage were analysed with respect to the above variables. Subsequently, 20 natural and 20 typodont teeth were utilized to establish the relationship in depth of damage caused by a high-speed diamond bur on typodont versus natural teeth. RESULTS: Dentists caused iatrogenic damage on 74% of approximal surfaces without protection, which fell to 50% and 46% respectively when matrix bands and wedges were used as guards. The corresponding rates of damage for students were 94%, 80% and 44%. There was no difference in depth of damage caused on the two types of teeth when bur was in contact with teeth for a very short time. CONCLUSIONS: Greater operator experience and the use of guards reduces iatrogenic damage to proximal surfaces during preparation with high-speed rotary instruments.

Pérdida auditiva inducida por ruido en estudiantes de la carrera de odontología / Noise induced hearing loss in dentistry students

Introducción: Los odontólogos se exponen desde su formación universitaria a sonidos potencialmente dañinos en forma rutinaria. Objetivo: Determinar si la presencia de escotoma en las frecuencias 3,4 y 6 kHz está asociada a la exposición a ruido de implementos dentales. Material y método: Se realizó un estudio de corte transversal en estudiantes expuestos a ruido en sus actividades prácticas dentales y otro grupo no expuesto. Se realizaron evaluaciones auditivas a ambos grupos, además de una sonometría y dosimetría en el laboratorio dental. Resultados: Se incluyeron 50 estudiantes de odontología expuestos a ruido de implementos dentales y 107 de otras carreras no expuestos. No se observaron diferencias significativas al comparar los umbrales de ambos grupos. Sin embargo, la frecuencia de escotoma en 4 kHz como en 6 kHz del oído izquierdo fue significativamente mayor en el grupo expuesto. Finalmente, la posibilidad de presentar un escotoma en 4 y 6 kHz del oído izquierdo estuvo significativamente asociada a exposición a ruido dental. Conclusión: La exposición a ruido derivado de prácticas dentales está asociado a escotoma en las frecuencias agudas. Sin embargo, la gran mayoría de los sujetos expuestos no evidenció una elevación de los umbrales por sobre el límite considerado normal.

Introduction: Starting with their time at college, dentists are routinely exposed to potentially harmful sounds. AIM: To determine whether the presence of notch in 3, 4 and 6 kHz frequencies is associated with exposure to noise from dental tools. Material and method: A cross-sectional study was performed with a group of students exposed to noise in their dental practices and with another group that was not exposed. Hearing tests were performed with both groups, along with a sound measurement and dosimetry in the dental laboratory. Results: Fifty dental students were exposed to the noise of dental implements and 107 students were not exposed. No significant differences were observed when comparing the thresholds of both groups. However, the frequency of notch at 4 kHz, as at 6 kHz in the left ear, was significantly higher in the exposed group. Conclusion: Noise exposure derived from dental practices is associated with notch at high frequencies. However, the vast majority of the subjects showed no evidence of a threshold higher than the limit that is considered normal.

Subcutaneous emphysema and pneumomediastinum complicating a dental procedure.

Cervicofacial emphysema and pneumomediastinum are rarely observed complications of dental interventions. The complications are associated with the use of a high-speed air-turbine dental drill. It is a potentially life-threatening condition, but the majority of cases are self-limiting and benign. We describe a patient with remarkable subcutaneous emphysema, pneumomediastinum, and partial pneumothorax after right second mandibular molar extraction. Dentists and physicians more often attribute the rapid onset of dyspnea in patients after a dental procedure to an allergic reaction to the anesthesia used during the procedure. Dentists and physicians should be aware that soft tissue emphysema can cause acute swelling of the cervicofacial region after dental procedures, which may mimic an allergic reaction.

General dental practitioners and hearing impairment.

OBJECTIVE: Hearing impairment (HI) remains a problem among dentists Hearing loss at speech frequencies was recently reported among dentists and dental hygienists. This study aimed to investigate prevalence and factors associated with perceived HI among dentists. METHODS: In 2009-2010, 100 general dental practitioners (GDPs) and 115 general (medical) practitioners (GPs) (mean ages, 43.7 and 44.4 years) from Rome (Italy), who commenced practice ≥ 10 years ago, were interviewed on a series of occupation- and recreation-related HI risk factors and on HI-associated symptoms (tinnitus, sensation of fullness, hypoacusis). Prevalence of presumptive HI (≥ 1 symptom perceived during workdays and weekends) was assessed and factors associated with presumptive HI were investigated. RESULTS: Prevalence was 30.0% (95% confidence interval, 21.0-39.0%) and 14.8% (95% confidence interval, 8.3-21.3%) among GDPs and GPs, respectively. Occupation (GDP vs. GP), family history of hypoacusis, hypertension, ear diseases and smoking were significantly associated with presumptive HI. Within GDPs alone, significant associations were found for frequent use of ultrasonic scalers, use of dental turbines aged≥1 year and prosthodontics as prevalent specialty. CONCLUSIONS: GDPs experienced HI risk than GPs. Such a risk was not generalized to all dentists, but was specific for those who frequently used noisy equipment (aged turbines, ultrasonic scalers) during their daily practice. CLINICAL SIGNIFICANCE: GDPs with 10 or more years of practice who routinely use potentially noisy equipment, could be at risk of HI. In order to prevent such condition, daily maintenance and periodical replacement of dental instruments is recommended.

Cervicofacial emphysema and pneumomediastinum after a high-speed air drill endodontic treatment procedure.

Cervicofacial subcutaneous emphysema is defined as the abnormal introduction of air in the subcutaneous tissues of the head and neck. It is mainly caused by trauma, head and neck surgery, general anesthesia, and coughing or habitual performance of Valsalva maneuver. The occurrence of subcutaneous emphysema after dental treatment is rare, and diffusion of gas into the mediastinum is much rarer, especially when the procedure is a nonsurgical treatment. The most common dental cause of pneumomediastinum is the introduction of air via the air turbine handpiece during surgical extraction of an impacted tooth. Only 6 cases of pneumomediastinum after endodontic treatment have been reported between 1960 and 2008. Pneumothorax is defined clinically as an "accumulation of air or gas between the parietal and visceral pleurae," and although it is often not a medical emergency, it can result in respiratory distress, tension pneumothorax, shock, circulatory collapse, and even death. Although there are many possible causes of dyspnea during a dental procedure, 1 rare complication is pneumothorax. Although specific closed turbine systems are available for oral surgical procedures, these drills may be used in exodontia to section teeth and facilitate tooth extraction. We report a case of cervical subcutaneous emphysema and pneumomediastinum occurring after an endodontic treatment of right first molar using an air-tribune drill. We present here in a case of massive pneumomediastinum and cervicofacial subcutaneous emphysema that occurred after opening the access cavity for endodontic treatment. We describe its etiologies and guidelines for its prevention during nonsurgical endodontic treatment.

Aerial dispersal of blood-contaminated aerosols during dental procedures.

OBJECTIVES: Dental procedures with high-speed instruments produce large amounts of aerosols. The present study aimed to clarify whether blood-contaminated aerosols were existent and floating in air during dental procedures and to evaluate the effect of an extraoral evacuator system. METHOD AND MATERIALS: An extraoral evacuator system with a test filter was used for sample collection at distances from 50 cm (n = 102) and 100 cm (n =124) behind the patient. A leucomalachite green presumptive test was performed on the test filter. One or more positive reactions on the test filter was considered a positive result, and the positive ratio in each procedure was compared. To assess the effect of the extraoral evacuator, an additional extraoral evacuator was introduced, and the positive ratio during third molar extractions at 100 cm behind the patient was compared (n = 55). RESULTS: At 50 cm from the mouth of the patient during third molar surgery, full-crown preparation, inlay cavity (Black Class II) preparation, and scaling with an ultrasonic scaler, positive results were obtained in 92% (12/13), 70% (21/30), 35% (9/26), and 33% (11/33) of cases, respectively. At a distance of 100 cm, positive ratios sustained 90% (35/39), 48% (15/31), 29% (6/21), and 12% (4/33), respectively. When the second extraoral evacuator was utilized, the positive ratio, at a distance of 100 cm, decreased significantly from 90% (35/39) to 60% (33/55) (P = .0015, chi-square test). CONCLUSION: This study showed that blood-contaminated aerosols can be suspended in air, even in general dental settings, and that extraoral evacuators are useful for reducing contaminated aerosols.

Subcutaneous emphysema during third molar surgery: a case report.

Extraction of third molars is the most common surgical procedure performed in oral surgery on a daily basis and, despite surgical skills and expertise, complications may occur. Complications observed during or after third molar removal may include pain, swelling, bleeding, infection, sinus perforation and nerve damage. Fortunately, with a proper management and a good surgical technique, the incidence of such events is low. Subcutaneous emphysema associated with dental extraction occurs when the air from the high-speed dental handpiece is forced into the soft tissue through the reflected flap and invades the adjacent tissues, leading to swelling, crepitus on palpation and occasionally spreading through the tissue spaces of the fascial planes. Although rare, iatrogenic subcutaneous emphysema can have serious and potentially life-threatening consequences. Care should be taken when using air-driven handpieces. The access of air into the facial tissues is not limited to tooth extractions, but may also occur through other portals of entrance, such as endodontically treated teeth, periodontium and lacerations of intraoral soft tissues. When subcutaneous emphysema occurs, it must be quickly diagnosed and properly managed to reduce the risk of further complications. This report presents a case of subcutaneous emphysema occurred during extraction of a mandibular third molar extraction with the use of an air turbine handpiece. Case management is described and issues relative to the diagnosis and prevention of this surgical complication are discussed.