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At least 433 records · Page 24Linked to original sources
PubMed2006

Accuracy of electronic apex locator in length determination in the presence of different irrigants: An in vitro study.

Determining the root canal length accurately had been a challenge in endodontics. Introduction of apex locators have definitely served as an effective adjuvant to radiographs. This in vitro study had attempted to compare the effectiveness of electronic apex locator in the presence of various canal contents. Comparison of the length determined by apex locators with the radiographic length was also made. The results of the study had shown that the length of root canals can be accurately made irrespective of the canal contents.

Bicuspid↗
PubMed1996

Use of an electronic apex locator on a cardiac pacemaker patient.

Modern cardiac pacemakers are complex and heterogenous devices. The potential effect of electrically powered instruments on a patient's pacemaker function must be carefully evaluated before treatment. Interference with the pacemaker's function by the instrument depends on the specific type of pacemaker placed and the patient's dependence on it. A case is presented in which an electronic apex locator was used on a patient with a pacemaker, despite the manufacturer's written warning to the contrary. The patient's cardiologist was consulted before treatment.

Arrhythmias, Cardiac↗
PubMedDate not supplied

A comparative evaluation of apical linear dye penetration of Glass ionomer based sealers with conventional root canal sealers. An in vitro study.

This study was done to evaluate the clinical practicality of a new Water mixable Glass ionomer root canal sealer with conventional type 11a Glass ionomer cement, if used as a sealer, along with Zinc oxide Eugenol and Calcium Hydroxide containing sealers. Forty freshly extracted single rooted Maxillary incisors were selected for the study. Ten teeth were assigned for each sealer group. Access cavity was prepared, wording length determined, modified step-back preparation and obturation of the root canal done with lateral condensation technique. Assigned groups were Group 1--Type 11a Glass ionomer cement, Group 11--Mixed Tubliseal, Group 111--Mixed Sealapex, Group IV--Endion. Micro leakage Values were assessed by the amount of linear dye penetration in to the apical pulp space. Statistical analysis was done with one way analysis (ANOVA), using Fisher's 'F' test and students unpaired 't' test. Seal apex exhibited the least micro leakage value and found to be the best sealer among the four sealer groups.

Analysis of Variance↗
PubMed1997

Root canal system of the mandibular incisor.

To better assess the efficiency of the mechanical preparation of root canals, 1085 transparent specimens of extracted mandibular incisors were examined for canal configuration, thickness and curvature of the root canals, condition of any accessory canals, and location of the apical foramen. Greater than 85% of the root canals possessed a single canal (Type I). Of specimens in which furcation was observed, only 3% possessed two separate canals (Type III and IV). Fewer than 30% of the specimens showed accessory canals that were mechanically impossible to clean. The majority of the lateral branches were small, greater than 80% of the specimens were smaller than a #15 reamer, and none of the branches were larger than a #30 reamer. Although apical foramina located distal to the apex were observed in about 50% of the specimens, 83.6% of all apical foramina were within 0.5 mm of the apex, and 99.5% were within 1.0 mm. Data on the thickness of the root and main canal in the apical portion and curvature of the root canal suggest that for adequate apical preparation, a #40 reamer must be able to reach the apical constriction.

Dental Pulp Cavity↗
PubMed1999

Super-EBA as an endodontic apical plug.

Forty extracted human single-rooted teeth were sequentially instrumented with nickel-titanium rotary files to a size 0.36 mm at the working length. Ten teeth were randomly assigned to the two control groups. The other 30 teeth were randomly divided into three groups and were obturated by a 5-mm apical plug of either Super-EBA, IRM, or laterally condensed gutta-percha and Roth's sealer. After 2 days, and at 1 month, the samples were tested for microleakage by the fluid filtration system under 15 psi. The negative controls were used to consider the time that it took the fluid filtration system to stabilize. A one-way analysis of variance showed that, at 1 month post obturation, there was no statistical difference in the ability of the three materials to seal the apex from coronal microleakage. However, at 2 days, Super-EBA gave a significantly better seal than IRM or laterally condensed gutta-percha and sealer.

Analysis of Variance↗
PubMed2005

Ex vivo comparison of two electronic apex locators with different scales and frequencies.

AIM: To compare ex vivo the accuracy of two impedance quotient apex locators with different scales and frequencies of the measuring circuit. METHODOLOGY: In each root of 193 extracted human teeth, electronic working length determination (ELD) was carried out with a newly constructed measuring unit. In all cases, ELD was performed using the apex locators Justy II (Hager & Werken, Duisburg, Germany) and Raypex (VDW, Munich, Germany) on the scale points (sp) 0/0.5/1 of each device. A Miller Needle reaching working length was fixed with composite. The corresponding sp and the differences to the other sp were recorded. After histological preparation of the apical region, the teeth were examined under a light microscope. The distances of the Miller Needle tips to the target intervals 'minor foramen-major foramen' and 'apical canal constriction' (apical constriction) were determined for each sp for both devices. The data were statistically analysed by a chi-square test. RESULTS: Precise determination of the target interval 'minor foramen-major foramen' was successful with Raypex 4 in 94.8% (sp 1), 90.7% (sp 0.5) and 72.5% (sp 0) of cases and with Justy II in 59.6% (sp 1), 92.2% (sp 0.5) and 68% (sp 0) of cases. No measurement carried out by Raypex 4 and by Justy II on sp 1 was beyond the major apical foramen. However, on sp 0.5, there were eight measurements for Raypex 4 and four measurements for Justy II beyond the major apical foramen. Overinstrumentation was also recorded for sp 0 in 49 specimens (Raypex 4) and 59 specimens (JustyII). The major apical constriction was met exactly by Raypex 4 in 50.7% (sp 1), 14% (sp 0.5) and 5.2% (sp 0) of cases and by Justy II in 32.1% (sp 1), 23.8% (sp 0.5) and 4.1% (sp 0) of cases. The differences between the determination made with the sp suggested by the manufacturers for Raypex 4 (sp 1) and Justy II (sp 0.5) were not significant (P > 0.05) for the target interval 'minor foramen-major foramen' and significant (P <or= 0.05) for the apical constriction. The differences between the sp of each device were significant (P <or= 0.05) for both target intervals. CONCLUSIONS: It is possible to determine the region between the minor and major apical foramen with electronic apex locators ex vivo. The best results were obtained using the sp advised by the manufacturers. Raypex 4 gave the best results on sp one without any measurement beyond the apical foramen. Use of ELD does not result in precise determination of the apical constriction.

Dental Pulp Cavity↗
PubMed2001

Detection of the apical lesion and the mandibular canal in conventional radiography and computed tomography.

OBJECTIVE: The purpose of this study was to compare the information gathered from dental radiography and high resolution computed tomography (CT) scans with regard to the detection of the endodontic lesion and its relation to the important neighboring anatomic structures such as the mandibular canal. STUDY DESIGN: Fifty patients with a persistent apical lesion referred for endodontic surgery were selected. The teeth involved were 6 mandibular premolars and 44 mandibular molars. Eighty roots were evaluated. For each case 1 CT scan and 1 periapical radiograph were taken. The apical lesion and the mandibular canal were evaluated for possible identification in CT scan or radiograph. The presence of the lesion was correlated to the findings during the surgical procedure. The CT scans of the involved roots were further evaluated with regard to the bone thickness and differentiation between cancellous and cortical bone. The position of the lesion/root within the mandible was studied in all dimensions. RESULTS: All 78 lesions diagnosed during surgery were also visible with the CT scan. In contrast, only 61 of the lesions were noted by conventional radiographs. The mandibular canal could be identified in 31 cases in dental radiographs, whereas in the oblique cuts of the corresponding CT scans the mandibular canal was detected in all patients. The amount of cortical and cancellous bone and the bone thickness as well as the three-dimensional extent of the lesion could only be adequately interpreted in CT scans. CONCLUSIONS: The use of CT provides additional, beneficial information not available from dental radiographs for treatment planning in apical surgery of mandibular premolars and molars. When the mandibular canal cannot be detected in dental radiographs or is in close proximity to the lesion or root apex, CT should be considered before endodontic surgery. The presence, extent, and location of the lesion and its relation to the mandibular canal can be predictably evaluated in a CT scan of the area.

Adult↗
PubMed2006

Root canal transportation with a Ni-Ti rotary file system and stainless steel hand files in simulated root canals.

OBJECTIVE: The purpose of this study was to compare the root canal transportation of the crown-down technique performed with the Ni-Ti rotary ProFile system (Dentsply/Maillefer), with the step-back technique using stainless steel K-Flexofiles (Dentsply/Maillefer). METHOD AND MATERIALS: Thirty simulated root canals in resin blocks were equally divided into 2 groups. The first group was instrumented with the ProFile system in a crown-down technique and the second group with hand K-Flexofiles in a step-back technique. After instrumentation, resin blocks of both groups were scanned by a transparency scanner, and the derived images were superimposed with the scanned image of an uninstrumented block. Transportation was digitally calculated by a computer software, and results were statistically evaluated by Student t test. RESULTS: Statistically significant differences (P < .05) were found among the 2 groups at 1, 2, 4, 5, and 6 mm from the apical foramen. No statistically significant difference was detected at 3 mm from the apical foramen. CONCLUSION: ProFile caused less transportation at 1 and 2 mm from the apex, whereas at 3 mm, both instrumentation techniques caused the same transportation. Standard deviation was less in the ProFile group than in the hand file group, indicating a more standardized preparation.

Dental Alloys↗
PubMed2000

Location of the apex of the lower central incisor.

Clinicians have always had difficulty finding the apex of the lower central incisor on a lateral cephalometric radiograph. This study was undertaken to define the radiographic anatomy surrounding the true apex. Standard cephalograms were taken of 38 skulls with metallic markers in the socket apex of 1 lower central incisor. Similar cephalograms were taken with the lower central incisor apex positioned in the central ray of the x-ray source. The comparison of the marked apices in the complete skulls and their separate mandibles showed that there was no distortion. Measurements from the markers to the lingual and labial symphyseal borders located the apices labial of center.

Adolescent↗
PubMed2000

Persistent pain related to root canal filling and apical fenestration: a case report.

Endodontic treatments may give rise to persistent pain whose origin is sometimes difficult to determine. Although it is unusual, pain may occur due to apical fenestrations following endodontic treatment. If this occurs, the solution is surgical intervention. This surgical procedure consists of raising a flap to expose the fenestration, followed by curettage of any overextended canal filling materials that may be potentially irritating to the underlying mucosa, remodeling of the apex, and its repositioning below the level of the cortical bone. A case is described that illustrates this clinical situation. The case also demonstrates information that can be obtained from tomodensitometric films.

Apicoectomy↗
PubMed2000

Apical microleakage of radiolabeled lysozyme over time in three techniques of root canal obturation.

The three methods of obturation assessed in this study were lateral condensation (80 teeth), Thermafil (40 teeth), and McSpadden (40 teeth). All teeth were prepared to the master apical file 30 and widened coronally by Gates Glidden burs before being randomly assigned to experimental groups to be filled by each technique; they were then sealed with nail polish, except for the apical 1 mm. Quantitative evaluation of apical microleakage for each technique was obtained after periods of 1 day, 7 days, 14 days, and 28 days of immersion in a lysozyme solution labeled with radioactive iodine by preparing horizontal sections of the teeth and measuring the level of radioactivity in each section using a gamma counter. Initial (1-day) leakage was least in the Thermafil group and was significantly different from the other techniques. Leakage was greatest in the laterally condensed samples. By the end of the study (28th day) values for lateral condensation were lowest, but were significantly different only for the McSpadden group. For all techniques leakage was most significant in the first 3 mm from the apex and was very low below this level so that all methods can be considered as giving a hermetic seal below 3 mm.

Analysis of Variance↗
PubMed2006

[Evaluation of antibacterial activity of apex-phoresis].

Effects of apex-phoresis on dental root canal microflora were studied and optimal dosage parameters were determined. Microbiological study in vitro has established that optimal antibacterial effect was achieved with the apex-phoresis dosage in the range between 2.5-5 mA/min. Study of the effects of apex-phoresis on dental root canal microflora in vivo disclosed its high antibacterial activity both in cases of pulpitis and destructive forms of chronic periodontitis. For the first time the data are confirmed by molecular-genetic method of detection of hard to cultivate virulent anaerobic bacteria. The results of the study allow to recommend apex-phoresis for wide use in clinical practice as an effective way to sterilize difficult to traverse dental root canals.

Adolescent↗
PubMed2000

Apical terminus location of root canal treatment procedures.

The apical termination of root canal treatment is considered an important factor in treatment success. The exact impact of termination is somewhat uncertain; most publications on outcomes are based on retrospective findings. After vital pulpectomy, the best success rate has been reported when the procedures terminated 2 to 3 mm short of the radiographic apex. With pulpal necrosis, bacteria and their byproducts, as well as infected dentinal debris may remain in the most apical portion of the canal; these irritants may jeopardize apical healing. In these cases, better success was achieved when the procedures terminated at or within 2 mm of the radiographic apex (0 to 2 mm). When the therapeutic procedures were shorter than 2 mm from or past the radiographic apex, the success rate for infected canals was approximately 20% lower than that when the procedures terminated at 0 to 2 mm. Clinical determination of apical canal anatomy is difficult. An apical constriction is often absent. Based on biologic and clinical principles, instrumentation and obturation should not extend beyond the apical foramen.

Dental Pulp Cavity↗
PubMed1998

Apical seal of roots obturated with laterally condensed gutta-percha, epoxy resin cement, and dentin bonding agent.

The apical seal of roots obturated with either of two kinds of dentin bonding agent, gutta-percha and epoxy-resin-based root canal sealer, was compared by a die leakage test with that of an epoxy resin root canal sealer and gutta-percha without a bonding agent. Thirty-two roots were prepared chemomechanically and divided into three experimental groups. Group 1 was filled with gutta-percha, epoxy-resin sealer, and All-Bond 2 Adhesive. Group 2 was filled with gutta-percha, epoxy-resin sealer, and Scotchbond Multi-Purpose Plus adhesive. Group 3 was filled with gutta-percha and epoxy resin sealer. The teeth were immersed in 2% methylene blue solution. Groups 1 and 2 leaked significantly less than group 3. The materials most frequently observed at the apex were in group 1 dental adhesive and in group 2 gutta-percha. The interface between dentin and the adhesive materials in groups 1 and 2 was examined by scanning electron microscope and showed a hybrid-like layer.

Dental Leakage↗
PubMed2005

The effect of disruption of apical constriction on periapical extrusion.

The aim of this study was to compare the amount of apical extrusion during manual instrumentation and engine-driven rotary instrumentation in teeth with disrupted apical constriction. Fifty-two teeth were divided into two groups comprising 26 teeth each. Teeth in each group were further divided into two sub-groups, the apices of which were enlarged approximately to a diameter of 0.2 mm and 0.4 mm. One group was instrumented using standardized technique with K-files and the other with ProFile .04 Taper Series 29, while irrigating with sodium hypochlorite. Glass vial model was modified for collection of extruded debris and irrigant as well as to integrate an electronic apex locator to the experimental assemble. The statistical analysis using Student's t test revealed no significant difference between instrumentation with K-files and ProFile .04 taper files (p > 0.05). There was a tendency with both techniques to extrude apically more material as the diameter of the apical patency increased.

Debridement↗
PubMed2004

Morphology of the physiological foramen: I. Maxillary and mandibular molars.

Information concerning the anatomy of the physiological foramen is limited. The aim of this study was to investigate the distance between the physiological and anatomical apex, accessory foramina frequency, and the shape and diameter of the physiological foramen in maxillary and mandibular molars. The apical anatomy of 523 maxillary and 574 mandibular molars from an Egyptian population was investigated by means of a computer-aided stereomicroscope (40 x magnification). The following results were obtained:

Dental Pulp Cavity↗
PubMed2000

Development of a frequency-dependent-type apex locator with automatic compensation.

Among apex locators, the frequency dependent type is more accurate and convenient to use than others. However, the accuracy of the apex locator is still influenced by the presence of various electrolytes used in root canal treatments. In this study, we developed a frequency-dependent electronic apex locator minimizing the influence of electrolytes on the measurement of root canal lengths. It was confirmed that the two frequencies of 0.5 and 10 kHz are better than the conventional ones of 0.4 and 8 kHz. The impedance ratio of the two different frequencies represents the position of the file in root canal, and the voltage difference of the two frequencies represents the status of the fluid in the root canal. As a result of compensation using the voltage differences of the two frequencies, the errors decreased significantly on average from +0.54 mm to +0.18 mm in H2O2 solution (p < 0.01), and from -0.33 mm to -0.01 mm in NaOCl solution (p < 0.01) in the tooth model experiments.

Analysis of Variance↗