Patients with persistent idiopathic dentoalveolar pain in dental practice.

AIM: To assess whether persistent idiopathic dentoalveolar pain (PIDAP), a diagnosis of exclusion, exhibits common features that can facilitate its diagnosis. PIDAP is defined by the International Classification of Orofacial Pain (ICOP 6.3.) as 'Persistent unilateral intraoral dentoalveolar pain, rarely occurring in multiple sites, with variable features but recurring daily for more than 2 h per day for more than 3 months, in the absence of any preceding causative event'. METHODOLOGY: In this observational study, participants fulfilling the new ICOP diagnostic criteria of PIDAP were included, covering 16 years of consecutive data. A systematic, retrospective assessment of patients utilizing the new PIDAP criteria on complaints of chronic tooth pain in a referral-based endodontic practice was undertaken. Non-idiopathic cases were excluded on the basis of clinical and radiologic findings. A modified neuropathic pain questionnaire was used to describe the painful sensations. Furthermore, allodynia in the periodontal space and sensory changes in the oral mucosa were assessed using a periodontal probe. RESULTS: Amongst the 160 patients assessed, 78 (63 women) fulfilled the strict PIDAP criteria. Pain history of PIDAP included no nocturnal awakening (85%) and a 'pulling/dragging' pain quality (59%). In 69% of the patients with PIDAP, pain was associated with a root filled tooth at the same site. In 14% of the cases, no endodontic treatment was performed in the affected quadrant. Mechanical allodynia in the gingival sulcus was observed in 91% of patients with painful teeth or implants. CONCLUSIONS: In this observational study, PIDAP mainly affected females and was associated with undisturbed sleep and periodontal allodynia.

A multicentric survey to evaluate preclinical education in Endodontology in German-speaking countries.

AIM: To evaluate preclinical education in Endodontology at Austrian, German and Swiss dental schools using an online survey. METHODOLOGY: An online survey divided into nine categories was sent using SurveyMonkey software to 37 dental schools, before the spread of the COVID-19 pandemic. The questionnaire included 50 questions to evaluate preclinical endodontic education, such as faculty-to-student ratios, topics taught and materials used, in preclinical phantom head courses. Seven and 14 days after the first e-mail contact, dental schools received a reminder e-mail. After four and six weeks, the dental schools were contacted by telephone and asked to participate in the online survey. The processing time was eight weeks in total. RESULTS: The response rate was 89%. Preclinical endodontic education at the participating dental schools differs considerably. Theory classes ranged from 1 to 70 h (15 h mean), and practical classes ranged from 3 to 78 h (39 h mean). The faculty-to-student ratio varied between 1:4 and 1:38 (1:15 mean). Forty-five per cent of the dental schools had a specialist in endodontics teaching theory. Several dental microscopes were available for preclinical teaching purposes at 82% of the dental schools. The majority (82%) taught root canal preparation with rotary or reciprocating NiTi instruments. Overall, 85% of the dental schools taught lateral compaction, amongst other methods, for canal filling. CONCLUSION: A substantial divergence amongst the dental schools regarding the time dedicated to theory and practical instruction in Endodontology was reported. However, convergence in the use of root canal treatment techniques and materials was reported.

Image quality of a portable X-ray device (Nomad Pro 2) compared to a wall-mounted device in intraoral radiography.

OBJECTIVES: The aim of this study was to determine whether a handheld (HH) X-ray device (Nomad Pro 2) is capable of producing equivalent or even superior X-ray image quality in comparison to a wall-mounted (WM) dental X-ray unit (Heliodent Plus) on the basis of objectifiable image quality parameters. METHODS: Anatomical, radiological and biological dental X-ray image quality parameters of a handheld dental X-ray device (Nomad Pro 2, Kavo Kerr, Biberach, Germany) were compared to a standard wall-mounted dental X-ray unit (Heliodent Plus, Sirona Dental Systems, Bensheim, Germany) using a maxillofacial phantom. In addition, the effect of different operators (dentists, dental students, dental assistants) on the dental X-ray image quality was measured. RESULTS: HH and WM devices showed comparable image quality for anterior teeth, premolars, molars and bitewing images. During the two-month investigational period, the radiation exposure level for the operator of the Nomad Pro 2 was 0.1 mSv for 203 images. Dentists as the highest trained personnel enrolled in the study achieved better image quality with the Nomad Pro 2 as compared to dental students and dental assistants, especially in the molar region. CONCLUSIONS: A HH device delivers a comparable image quality to a WM device. In addition, there seem to be short learning curves with regard to image acquisition when using a handheld device, which is further minimised by the previous training of the operating personnel. HH dental X-ray devices, such as the Nomad Pro 2 are a promising adjunct for dental radiology in cases where WM units are of limited practicability.

When and how do endodontic specialists use cone-beam computed tomography?

This study investigated the use of cone-beam computed tomography (CBCT) by endodontists in Germany and Switzerland. Sixty-eight German endodontic specialists (G-ES), 22 Swiss endodontic specialists (CH-ES) and 95 dentists with a German Master of Science in endodontics (MSc) were invited to participate. Data on the timing of diagnostic assessments, endodontic case difficulty and indications for CBCT use were collected by questionnaire. The frequencies of pre-, intra- and postoperative use of periapical radiography and CBCT were analysed by case difficulty level. In high difficulty cases, access to a CBCT device was significantly associated with the frequency of both pre- and intraoperative CBCT use. The type of endodontic qualification had a significant impact on the rate of preoperative CBCT use in high difficulty cases. German endodontic specialists used preoperative CBCT more frequently than CH-ES and MSc. Our findings show that CBCT is a valuable imaging tool for endodontists, particularly in high difficulty cases.

Accuracy and consistency of electronic root canal length determination with electrically isolating rubber stoppers.

The aim of this study was to investigate the influence of an isolating silicone stopper on the measuring accuracy and display consistency of three electrometric apex locators. The length of the canal to the major foramen was determined electrometrically using an ISO size 10 file in 20 extracted teeth each with natural crowns (Group I), amalgam fillings (Group II) or base-metal crowns (Group III), The measurements were performed with isolating or conventional silicone stoppers using three different apex locators with a four-level scale consistency rating. The use of isolating stoppers resulted in a more consistent display than with conventional stoppers, independent of the presence or type of coronal restoration (P = 0.017). Across all coronal restorations, the position of the major foramen could be determined to within ± 0.5 mm without significant differences (P = 0.79) using conventional and isolating stoppers. The use of modified isolating stoppers provides a significant increase in display consistency.

Biliary Stenosis and Gastric Outlet Obstruction: Late Complications After Acute Pancreatitis With Pancreatic Duct Disruption.

OBJECTIVES: Pancreatic duct disruption (PDD) after acute pancreatitis can cause pancreatic collections in the early phase and biliary stenosis (BS) or gastric outlet obstruction (GOO) in the late phase. We aimed to document those late complications after moderate or severe acute pancreatitis. METHODS: Between September 2010 and August 2014, 141 patients showed pancreatic collections on computed tomography. Percutaneous drainage was primarily performed for patients with signs or symptoms of uncontrolled pancreatic juice leakage. Pancreatic duct disruption was defined as persistent amylase-rich drain fluid or a pancreatic duct cut-off on imaging. Clinical course of the patients who developed BS or GOO was investigated. RESULTS: Among the 141 patients with collections, 33 patients showed PDD in the pancreatic head/neck area. Among them, 9 patients (27%) developed BS 65 days after onset and required stenting for 150 days, and 5 patients (15%) developed GOO 92 days after onset and required gastric decompression and jejunal tube feeding for 147 days (days shown in median). All 33 patients recovered successfully without requiring surgical intervention. CONCLUSIONS: Anatomic proximity of the bile duct or duodenum to the site of PDD and severe inflammation seemed to contribute to the late onset of BS or GOO. Conservative management successfully reversed these complications.

A Comparison of 2- and 3-dimensional Healing Assessment after Endodontic Surgery Using Cone-beam Computed Tomographic Volumes or Periapical Radiographs.

INTRODUCTION: The aim of this study was to compare the assessment of healing after endodontic microsurgery using 2-dimensional (2D) periapical films versus 3-dimensional (3D) cone-beam computed tomographic (CBCT) imaging. METHODS: The healing of 51 teeth from 44 patients was evaluated using Molven's criteria (2D) and modified PENN 3D criteria. The absolute area (2D) and volume (3D) changes of apical lesions preoperatively and at follow-up were calculated by segmentation using OsiriX software (Pixmeo, Bernex, Switzerland) and ITK-Snap (free software). RESULTS: There was a significant difference between the mean preoperative lesion volumes of 95.34 mm3 (n = 51, standard deviation [SD] ±196.28 mm3) versus 6.48 mm3 (n = 51, SD ±17.70 mm3) at follow-up (P < .05). The mean volume reduction was 83.7%. Preoperatively, mean lesion areas on periapical films were 13.55 mm2 (n = 51, SD ±18.80 mm2) and 1.83 mm2 (n = 51, SD ±.68 mm2) at follow-up (P < .05). According to Molven's criteria, 40 teeth were classified as complete healing, 7 as incomplete healing, and 4 as uncertain healing. Based on the modified PENN 3D criteria, 33 teeth were classified as complete healing, 14 as limited healing, 1 as uncertain healing, and 3 as unsatisfactory healing. The variation in the distribution of the 2D and 3D healing classifications was significantly different (P < .05). Periapical healing statuses incomplete healing or uncertain healing according to Molven's criteria could be clearly classified using 3D criteria. CONCLUSIONS: CBCT analysis allowed a more precise evaluation of periapical lesions and healing of endodontic microsurgery than periapical films. Significant differences existed between the 2 methods. Over the observation period, the mean periapical lesion sizes significantly decreased in volume. Given the correct indications, the use of CBCT imaging may be a valuable tool for the evaluation of healing of endodontic surgery.

Intracanal use of heated rinsing solutions: A pilot study.

OBJECTIVE: The tissue-dissolving and bactericidal activity of sodium hypochlorite (NaOCl) can be increased by warming the NaOCl solution without concurrently increasing its toxicity. The present study was set up to determine if and to what extent a heated liquid reaches the apical region. METHOD AND MATERIALS: A temperature sensor was introduced from the apical aspect into a human canine 22 mm in length prepared to size 40.04. At 37°C in the incubator the canal was irrigated with water 10 times each at temperatures of 10°C, 21°C, 45°C, 60°C, and 37°C (control group). The apical temperature curve was recorded with a one-second resolution from the time the irrigation started until at least 2 minutes after its end. RESULTS: None of the measurements yielded the same temperature in the apical region as that of the coronally introduced liquid. At 60°C, a maximum value of 52.2°C ±â€¯1.39°C, and at 10°C, a minimum value of 16.09°C ±â€¯0.39°C, was achieved apically. At 1 minute after the end of active rinse cycle, the temperature at the apical probe differed only 4.8°C to 0.9°C ±â€¯1.41°C from the initial value (about 37°C). Only with the cold 10°C solution was the temperature difference higher, at 7.5°C ±â€¯2.14°C. CONCLUSION: The benefit of heating irrigants accrues primarily during the period of active rinsing; immediately after the end of the rinsing cycle, body temperature is reached again. A positive aspect to be noted is that an irrigant stored at room temperature is quickly warmed to 37°C in the root canal by the temperature of the body.

Better Outcomes if Percutaneous Drainage Is Used Early and Proactively in the Course of Necrotizing Pancreatitis.

PURPOSE: To compare outcomes after percutaneous catheter drainage (PCD) for acute necrotizing pancreatitis versus those in a randomized controlled trial as a reference standard. MATERIALS AND METHODS: Between September 2010 and August 2014, CT-guided PCD was the primary treatment for 39 consecutive patients with pancreatic necrosis. The indication for PCD was the clinical finding of uncontrolled pancreatic juice leakage rather than infected necrosis. Subsequent to PCD, the drains were proactively studied with fluoroscopic contrast medium every 3 days to ensure patency and position. Drains were ultimately maneuvered to the site of leakage. These 39 patients were compared with 43 patients from the Pancreatitis, Necrosectomy versus Step-up Approach (PANTER) trial. RESULTS: The CT severity index was similar between studies (median of 8 in each). Time from onset of acute pancreatitis to PCD was shorter in the present series (median, 23 d vs 30 d). The total number of procedures (PCD and subsequent fluoroscopic drain studies) per patient was greater in the present series (mean, 14 vs 2). More patients in the PANTER trial had organ failure (62% vs 84%), required open or endoscopic necrosectomy (0% vs 60%), and experienced in-hospital mortality (0% vs 19%; P < .05 for all). CONCLUSIONS: Even though patients in the present series had a similar CT severity index as those in the PANTER trial, the former group showed lower incidences of organ failure, need for necrosectomy, and in-hospital mortality. The use of a proactive PCD protocol early, before the development of severe sepsis, appeared to be effective.

A percutaneous drainage protocol for severe and moderately severe acute pancreatitis.

BACKGROUND: According to the revised Atlanta classification, severe and moderately severe acute pancreatitis (AP) includes patients with pancreatic and peripancreatic collections with or without organ failure. These collections suggest the presence of pancreatic juice leakage. The aim of this study was to evaluate the efficacy of a percutaneous catheter drainage (PCD) protocol designed to control leakage and decrease disease severity. METHODS: Among 663 patients with clinical AP, 122 were classified as moderately severe or severe AP (all had collections). The computed tomography severity index (CTSI) score was calculated. The indication for PCD was based on progressive clinical signs and symptoms. Drain patency, position, and need for additional drainage sites were assessed using CT scans and drain studies initially every 3 days using a proactive protocol. Drain fluid was examined for amylase concentration and microbiological culture. Clinicopathological variables for patients with and without PCD were compared. Since there was no mortality, we used prolonged drainage time to measure the success of PCD. Within the group treated with PCD, variables that resulted in prolonged drainage time were analyzed. RESULTS: PCD was used in 47/122 (39 %) patients of which 33/47 (70 %) had necrosis. PCD cases had a median CTSI of 8 and were classified as moderately severe AP (57 %) and severe AP (43 %). Inhospital mortality was zero. Surgical necrosectomy was not required for patients with necrosis. Independent risk factors for prolonged drainage time were persistent organ failure >48 h (P = 0.001), CTSI 8-10 (P = 0.038), prolonged duration of amylase-rich fluid in drains (P < 0.001), and polymicrobial culture fluid in drains (P = 0.015). CONCLUSIONS: A proactive PCD protocol persistently maintaining drain patency advanced to the site of leak controlled the prolonged amylase in drainage fluid resulting in a mortality rate of zero.

Homogeneity of root canal fillings performed by undergraduate students with warm vertical and cold lateral techniques.

OBJECTIVES: The aim of this study was to determine radiographic and microscopic appearances of root canal fillings performed by undergraduate students using vertical and lateral compaction techniques. STUDY DESIGN: Thirty dental students were instructed how to fill curved simulated canals with gutta-percha and sealer using lateral and vertical compaction. Digital radiographs were taken in buccolingual and mesio-distal projections; radiographs were evaluated for homogeneity and root canal wall contact. Plastic blocks with simulated canals were sectioned and cross sections were assessed under a light microscope for voids. Probabilities were expressed as odds ratios (OR) with 95% confidence intervals (CI). RESULTS: Radiographs showed that the chances of obtaining a homogeneous root canal filling by using a vertical compaction technique were 3 times higher in the coronal canal third (OR 3.2; CI: 1.9, 5.3), the same in the middle third, and 2 times higher in the apical third (CI: 1.1, 2.4) than when using lateral compaction. Microscopic evaluation of the same canals revealed that the chances of obtaining a homogeneous root canal filling by vertical compaction were 3 times higher in the coronal canal third (CI: 1.6, 5.8), almost 3 times higher in the middle canal third (CI: 1.6, 4.7), and about 10 times higher in the apical canal third (OR 9.8; CI: 2.2, 43.4) than by lateral compaction. The chances of transporting filling material beyond the apex were almost 5 times higher (OR 4.6; CI: 2.8, 7.6) when using vertical rather than lateral compaction. CONCLUSION: Inexperienced students obtained more homogeneous root canal fillings with the vertical compaction method; however, the probability of overextruding filling material with this method was high.

A highly conserved alanine in the S6 domain of the hERG1 K+ channel is required for normal gating.

The central cavity of K(+)-selective ion channels is lined by four S6 transmembrane alpha-helices. An Ala residue is located near the midpoint of each S6 and marks the narrowest point of the central cavity. In hERG1 channels, we determined the functional consequences of substituting this conserved Ala (Ala653) with other hydrophobic or charged amino acids. Mutant channels were expressed in Xenopus oocytes and ionic currents measured by using the two-microelectrode voltage clamp technique. Substitution of Ala653 with bulkier hydrophobic residues (Val, Leu, Ile, Met, Phe, Trp) did not prevent ion conduction, but the mutant channels activated at more negative potentials compared to wild-type channels. The half-point for voltage dependent activation was shifted by -54 mV for the most conservative hydrophobic mutation, A653V. Oxidation of A653C hERG1 channels induced a maintained current at negative membrane potentials. This effect was not reversible with dithiothreitol, indicating that the sulfhydryl side-chains of Cys653 were oxidized to a negatively charged sulfinic or sulfonic acid. Substitution of Ala653 with acidic (Asp, Glu) or basic (Arg, Lys) residues prevented channel deactivation. Thus, an Ala at position 653 in hERG1 is required for normal voltage dependence of channel gating and a charged residue in this position prevents channel closure.

Root canal preparation with the NiTi systems K3, Mtwo and ProTaper.

The aim of this paper was to examine the result of rotary root canal preparation with the nickel-titanium (NiTi) systems K3, ProTaper and Mtwo. One hundred and fifty curved artificial root canals and 60 mesial canals of human mandibular molars were selected. In the group of curved artificial canals, all canals were prepared to size 35/0.04 taper with the three systems. In the group of human mandibular molars, the teeth with mature root canals were radiographed with silver points inserted in bucco-lingual and in mesio-distal positions. In the artificial root group, one K3 instrument separated. Mtwo (20%) showed significantly (P = 0.003) less zips than K3 (46.9%) or ProTaper (50%). There were no significant differences in ledge and elbow formation. K3 and Mtwo had the lowest percentage of canal transportation. There was no significant difference regarding the preparation length or the condition of the apical foramina following the preparation. Canals prepared with K3 (26.5%) were significantly (P < 0.001) less tapered than ProTaper (62%) and Mtwo (82%). In the human mandibular molar group, one Mtwo and one ProTaper instrument separated. No significant differences were found in the preparation length, transportation or taper. The three systems tested, K3, Mtwo and ProTaper, achieved good preparation results.

Effect of prion decontamination protocols on nickel-titanium rotary surfaces.

Decontamination of instruments is a prerequisite for their potential reuse but may affect surface integrity. Hence, the effect of prion removal protocols on 7 brands of nickel-titanium files was investigated. Baseline debris scores were determined under magnification after staining with van Gieson's solution. After shaping root canals in vitro, rotaries were mechanically and ultrasonically cleaned followed by immersion for 24 hours in 2 M sodium hydroxide (NaOH), 6 M CH(5)N(3), or 3% sodium hypochlorite (NaOCl); control files were stored dry. After sterilization, files were again stained and evaluated. Two of seven file brands demonstrated significantly higher baseline debris scores compared to final scores. Uniformly, debris could not be completely removed; there were no significant differences among groups. After immersion in NaOCl, 27.8% of instruments showed corrosion; however, no deterioration after immersion in the other solutions was found in the other groups. Regarding corrosion, no significant difference was found between brands. Based on these findings, single use of nickel-titanium rotaries appears beneficial.

Mutational biases associated with potential iron-binding DNA motifs in rodent lacI and human p53 mutational databases.

The role of Fenton oxidants in DNA damage, aging, and cancer is appreciated, but not well understood. Six potential iron-binding (PIB) DNA motifs were previously identified as sites of preferential strand cleavage. Since DNA-metal binding domains are a known determinant of oxidative DNA damage, and the location of strand breaks explains where oxidant attack occurs, we sought to determine whether the likelihood of base change mutations is a function of neighboring PIB motifs. We developed a sliding window function that computes the density of PIB motifs on both strands, within 4-12bp, for each location along a target gene. This range of window sizes reflects known diffusion distances of Fenton reaction products. Using mutational databases, odds of mutation at each base were calculated relative to PIB motif density, for all PIB motif types in aggregate, or for individual PIB motifs. Using mutational data from lacI transgenic animals, we observed a non-random distribution of PIB motifs, associated with increased odds of mutation, showing a strand bias. Sensitivity analysis confirmed that the optimum association between PIB motif density and mutations occurs when a 7bp radius is used for the window size. Randomly simulated mutations showed no association with PIB motif density. When the method was applied to human TP53 mutation data, we saw similar results, but no strand bias. As PIB motif density rises, linear trends are observed for increasing odds of mutation. Sensitivity analysis revealed associations between PIB motifs and GC --> AT transitions and GC --> TA transversions-the most commonly observed types of mutations arising from oxidative DNA damage. DNA-metal binding motifs are found in a wide variety of biological contexts, including many where conformational sensitivity to redox state is important. These techniques can help elucidate how DNA-iron-binding may affect lesions and subsequent mutations from multiple agents.