Radiographic Working Length Research Articles

Tactile working length determination for root canal therapy in underserved settings.

Multicentre randomised controlled clinical trial in a rural underserved African setting. The technical and electrical infrastructure still remains unstable in Gambia. Therefore, block randomisation was chosen. Patients included in 2010 were treated according to the original BRT method with tactile working length determination, whereas patients included in 2011 were treated with radiographic working length control. During the latter study period and the 24-month evaluation, a generator was provided to ensure sufficient power supply to run a radiographic unit. The primary end point was the apical extension score of the radiographic quality parameter of root canal fillings. The secondary radiographic end point was the periapical index, and the secondary clinical end point was tooth tender to percussion. The safety end point was tooth loss as a consequence of endodontic failure. BRT with tactile working length determination compared with standard radiographic working length control did not significantly differ in terms of radiographic and clinical outcomes after 24 months. The apical extension of the root canal fillings and the periapical anatomic structures showed no significant differences according to radiographic analyses (P = 0.5). Corresponding results were found in clinical aspects of tooth tender to percussion (P = 0.6) and tooth loss (P = 0.7). Within the limits of this randomised controlled trial it was shown that tactile working length determination in BRT resulted in comparable treatment outcomes in radiographic and clinical aspects compared with standard endodontic treatment with radiographic working length determination. Tactile working length determination turned out to be an accurate method in BRT.

Clinical Effectiveness of Basic Root Canal Treatment after 24 Months: A Randomized Controlled Trial

IntroductionThe purpose of this study was to investigate the effectiveness of basic root canal treatment (BRT) with tactile working length determination in terms of radiographic and clinical outcome parameters compared with endodontic treatment with standard radiographic working length control. MethodsThis was a clinical, multicenter, controlled, open-label trial to evaluate BRT effectiveness after 24 months. The primary end point was the apical extension score of the radiographic quality parameter of root canal fillings. The secondary radiographic end point was the periapical index, and the secondary clinical end point was tooth tender to percussion. The safety end point was tooth loss as a consequence of endodontic failure. Statistical analyses of binary and categoric data were calculated using cross tables and the chi-square test. ResultsBRT with tactile working length determination compared with standard radiographic working length control did not significantly differ in terms of radiographic and clinical outcomes after 24 months. The apical extension of the root canal fillings and the periapical anatomic structures showed no significant differences according to radiographic analyses (P = .5). Corresponding results were found in clinical aspects of tooth tender to percussion (P = .6) and tooth loss (P = .7). ConclusionsTactile working length determination in BRT resulted in comparable treatment outcomes compared with standard endodontic treatment with radiographic working length control and turned out to be an accurate method in BRT.

Radiographic assessment of endodontic working length

The use of radiographs for working length determination is usual practice in endodontics. Exposing radiographs following the principles of the paralleling technique allows more accurate length determination compared to the bisecting-angle method. However, it has been reported that up to 28.5% of cases can have the file tip extending beyond the confines of the root canals despite an acceptable radiographic appearance. The accuracy of radiographic working length determination could be affected by the location of the apical foramen, tooth type, canal curvature and superimposition of surrounding structures. Variations among observers by virtue of training and experience may also influence the accuracy of the procedure. The interpretation of radiographs could be affected by film speed and viewing conditions, with the superiority of digital imaging over conventional radiography for working length determination remaining debatable. The combination of several methods is recommended for acquiring the most accurate working length.

Efficiency of 2 electronic apex locators on working length determination: A clinical study

Aims:The aim of this clinical study was to evaluate the clinical accuracy of two electronic apex locators (EALs).Materials and Methods:A total of 120 patients with 283 roots were randomized into three groups including, traditional radiographic method, EAL (Root ZX mini), and apex locating endodontic motor (VDW Gold) for working length (WL) determination. Root canals were instrumented to a size ProTaper F3 nickel titanium file. The obturation quality of matched tapered master cone (ProTaper F3) was determined for the accuracy of WL.Statistical Analysis Used:Descriptive statistics were expressed as numbers and percentages. Pearson Chi-square test was used to determine for differences between groups. P < 0.05 was considered statistically significant for all tests.Results:There was no statistically significant difference between the three tested groups (P = 0.894).Conclusions:The success of both apex locators was similar to the radiographic WL determination technique.

The use of radiography and the apex locator in endodontic treatment within the UK: a comparison between endodontic specialists and general dental practitioners

To investigate the attitudes of general dental practitioners (GDPs) and specialist endodontists working in the UK in the use of radiography and apex locators during root canal treatment and to see if use was related to respondent's age and the year of graduation. A postal questionnaire was sent to 857 randomly selected GDPs and all endodontic specialists working in the UK (170). Non-responders were sent a further two mailings. Chi-squared tests were used to compare both groups at the P < 0.05 level of significance. For nonparametric data, the Mann-Whitney U test was employed. The overall response rate was 73%. There were significant differences between endodontic specialists and GDPs in the prescription of the preoperative, the cone-fit and the postoperative radiograph. A total of 114 (86.4%) endodontic specialists and 321 (53.2%) GDPs reported using an apex locator (P < 0.001). Eighty-eight (66.7%) endodontists and 217 (36%) GDPs used an apex locator and a radiograph to determine the working length for a single-rooted tooth (P < 0.001). For multi-rooted teeth, 91 (68.9%) endodontists and 229 (38%) GDPs used a combined approach of an electronic apex locator and a working-length radiograph (P < 0.001). One-millimetre short of the radiographic apex was employed by 56.2% of respondents as the apical limit. There were significant differences (P < 0.001) between the two groups with regard to routine radiographic follow-up. Both endodontists and GDPs were found to be observing national guidelines when performing root canal treatment. Greater use of apex locators was found amongst endodontists who tended to use a combined approach of an apex locator and periapical radiography.

Influence of clinical experience on the radiographic determination of endodontic working length

To determine the influence of clinical experience on the accuracy and consistency of estimation of radiographic working length (WL) for the root canal treatment of single-rooted teeth. Forty conventional WL periapical radiographs that included variations in file length were selected. They were digitally scanned and arranged in PowerPoint presentations on CDs. These were distributed to three assessor groups; fourth-year undergraduates at two stages of training (Groups 1 and 2) and endodontic postgraduates (Group 3). Participants were asked to determine the adjustment needed in millimetres to position the file tip at the correct WL for each image. A gold standard file position was provided by three experienced endodontists. For inter-group comparison of scores, the Kruskal-Wallis, ANOVA and post hoc Bonferroni tests were used. Evaluation of intra-examiner consistency was with the Kappa test. To evaluate intra-group consistency, the Wilcoxon signed rank test was used to compare the frequency of weighted correct scorings. File adjustments of Group 3 were significantly more accurate than those of Group 1 (P = 0.006). The scores of Group 3 were also better than those of Group 2, although the difference was not significant. When the scores of the undergraduate groups were compared, the difference was not statistically significant. The consistency of the groups was not affected by a 2-week pause between assessments, and no definite pattern could be detected across any of the groups with the Kappa test. Clinical experience after graduation influenced the accuracy of estimating the adjustments needed for correct radiographic WL of single-rooted teeth. The most experienced group was significantly more accurate than the other groups.

Influence of pulp condition on the accuracy of an electronic foramen locator in posterior teeth: an in vivo study

The aim of this study was to assess, in vivo, the accuracy of the NovApex® electronic foramen locator in determining working length (WL) in vital and necrotic posterior teeth. The NovApex®was used in 144 canals: 35 teeth with vital pulps (68 canals) and 42 teeth with necrotic pulps (76 canals). WL was measured with the NovApex® locator and confirmed using the radiographic method. Differences between electronic and radiographic measurements ranging between 0.0 and 0.4 millimeters were classified as acceptable; differences equal to or greater than 0.5 millimeter were considered unacceptable. Pearson's chi-square test was used to assess the influence of pulp condition on the accuracy of NovApex®(a = 0.05). Regardless of pulp condition, differences between electronic and radiographic WL measurements were acceptable in 73.61% of the canals. No statistically significant differences in accuracy were observed when comparing vital and necrotic canals (p > 0.05). There were 38 unacceptable measurements. In none of these cases was the file tip located beyond the radiographic apex; in 32, it was located short of the NovApex® measurement. Pulp condition had no significant effect on the accuracy of NovApex®.

Clinical evaluation of Root ZX II electronic apex locator in primary teeth

To evaluate the accuracy of Root ZX II electronic apex locator (EAL) for root canal working length determination in primary teeth. Forty primary maxillary incisor teeth were included in the study. Root ZX II EAL was used to determine the electronic working length (EL). The working length obtained with EAL was evaluated using digital radiography with the measuring file set to EL. The samples were categorised into three groups. Group 1 (acceptable): file tip 0-1mm short of the radiographic apex; Group 2 (short): file tip > 1mm short of the apex and Group 3 (long): file tip beyond the apex. Digital radiographic working length (RL) was derived by adjusting EL to the radiographic apex. The assigned calibrations were tabulated and statistically analysed. Group 1 included 28 out of 40 teeth indicating a clinical accuracy of 70%. Group 2 contained 10 (25%) teeth whereas group 3 had only 2 (5%) teeth. Pearson correlation coefficient statistical analysis showed a high correlation (r = +0.82; p<0.001) among the groups. Root ZX II EAL can be used as a reliable device for obtaining root canal length in primary maxillary incisor teeth.

Working length determination in general dental practice: a randomised controlled trial

To evaluate the ability of apex locators as a tool in determining working length in comparison to traditional working length radiographs in general dental practice. Randomised controlled clinical trial. General dental practices in the North West of England.Subjects Adults requiring root canal treatment of at least one tooth with minimal or moderate difficulty. Root canal treatment was carried out with the working length determined by apex locator in the treatment group (AL), and periapical radiograph in the control group (PA). The acceptability of the master cone gutta percha measured from a radiograph before obturation was used as the primary outcome. Twenty-one of 23 fillings in the AL group were judged as acceptable, compared to 17 of 23 fillings in the PA group. This difference was not statistically significant. In general dental practice, no significant difference was found in working length determined using apex locator combined with a master cone GP radiograph or using the conventional method. There is a need for larger trials to investigate these methods further.

Comparison Between the Accuracy of NovApex Apex Locator and Radiographs in Determining Radiographic Apex.

Determination of the canal working length with radiographs has many drawbacks. Electronic apex locators have been developed to overcome some of these problems. Recently, a newly designed apex locator called NovApex has been introduced. All the studies conducted to determine the accuracy of NovApex have been carried out in-vitro on extracted teeth. The aim of this in vivo study was to evaluate the accuracy of NovApex compared with traditional radiographic method. Twenty-five patients whose lower molars that were candidates for extraction were selected. The teeth were accessed, and the radiographic working length was determined by measuring the length of the initial file 0.5mm short of the radiographic apex. Then, NovApex apex locator was used to measure the electronic working length. Subsequently, the tooth was extracted, and the actual working length was measured by introducing a size #15 K-file into each canal until the file tip was visible at the apex, then 1.5mm was subtracted to attain the working length. Cohen's Kappa was computed for each of the methods versus actual working length as a measure of reliability. The accuracies were compared using Chi-square test. The accuracy of NovApex apex locator and radiographic method in detecting the apical end point within ±0.5mm was 74.7% and 68%, respectively; this was not significantly different (P<0.001). The NovApex apex locator is useful in detecting the apical end point with the accuracy similar to radiographic method. However, neither technique is fully reliable in detecting the apical end point of the canal.

Radiographic versus electronic root canal working length determination

The aim of this ex vivo study was to compare the accuracy of radiographic and electronic root canal length determination methods, compared with actual root canal length obtained with stereomicroscope. Thirty extracted single-rooted permanent teeth were used for this study. After access preparation, actual length (AL) of the root canal were determined for each tooth by inserting a #15 file until the tip of the file was visible at the apical foramen under a stereomicroscope. The radiographic working length determination was determined with a digital radiographic system and for the electronic measurement all teeth were embedded in an alginate model to test apex locator in-vitro. Data was analyzed using the descriptive statistic and intraclass correlation coefficient. No significant difference was found between the radiographic and electronic root canal working length determination (P>0.05). The percentage of electronic measurements within ± 0.5 mm to the apical constriction was 93.34% and 90% for radiographic methods within ± 0.5 mm of all cases compared with AL. The present ex vivo study showed that electronic root canal working length determination is not superior to radiographic methods. Both methods provided a good performance in determining the root canal working length.

Effect of Working Length Measurement by Electronic Apex Locator or Radiography on the Adequacy of Final Working Length: A Randomized Clinical Trial

Introduction Obtaining a correct working length is critical to the success of endodontic therapy. The aim of this clinical study was to compare the effect of working length determination using electronic apex locator or working length radiograph on the length adequacy of final working length as well as the final obturation. Methods A total of 84 patients with 188 canals were randomized into two groups; in group 1, the working length was determined by working length radiograph, whereas in group 2, it was determined by the Raypex5 electronic apex locator (VDW, Munich, Germany). Length adequacy was assessed in each group for master cone and final obturation radiography and categorized into short, acceptable, and over cases. Results There was no statistically significant difference between the rates of acceptable (master cone radiography: group 1 = 82.1% and group 2 = 90.4%; final radiography: group 1 = 85.7% and group 2 = 90.4%) and short cases (master cone radiography: group 1 = 7.1% and group 2 = 8.7%; final radiography: group 1 = 1.2% and group 2 = 1%) between the two groups. Over cases in master cone radiography were significantly more in group 1 (10.7%) than group 2 (1%) (χ 2, p = 0.00). However, this category did not show a significant difference for final obturation between group 1 (13.1%) and group 2 (8.7%). Conclusion The results of endodontic treatment using the Raypex5 electronic apex locator are quite comparable, if not superior, to radiographic length measurement regarding the rates of acceptable and short cases. Furthermore, in addition to reducing the radiographic exposure, electronic apex locators are superior in reducing overestimation of the root canal length.

Consistency of Apex Locator Function: A Clinical Study

The consistency of apex locators was determined by calculating the dysfunction frequency. Electronic working length (EWL) was determined in 507 patients requiring endodontic treatment. Different clinical parameters were recorded including tooth vitality, presence of obliteration, and metallic restoration. Two apex locators were used (Root ZX [Morita, Tokyo, Japan] and Raypex5 [VDW, Munich, Germany]). Apex locator performance was considered “consistent” when the scale bars were stable and moved only in correspondence to the movement of file in the root canal. A working length radiograph with files set to the EWL was performed. EWL were considered “acceptable” when the file tip was located 0 to 2 mm short of the radiographic apex. The function of apex locators was consistent in 85% of the patients (429/507 [99% confidence interval, 80-88]). The inconsistent measurements were strongly associated with partially or totally obliterated root canals (p < 0.0001). Radiographically, 97% of consistent measurements were “acceptable.”

An in vivo comparison of working length determination by only root-ZX apex locator versus combining root-ZX apex locator with radiographs using a new impression technique

The objective of this study was to compare, in vivo, the accuracy of working length determination using only the Root-ZX electronic apex locator versus adjusting Root-ZX measurements after obtaining a working length radiograph. The working length was determined in 25 premolar root canals using Root-ZX and K-files were fixed at these positions. Radiographs were acquired and interpreted, and the recorded working length measurement was adjusted, if necessary, for a combined measurement. The teeth were then extracted in an effort to determine the position of the file tip to the root canal constriction. On the basis of the position of the file tip to the apical foramen, polyvinylsiloxane impressions of the root apex were taken, or the root was imbedded in acrylic resin and ground in order to measure the position of the file tip to the apical constriction. The Root-ZX alone detected the apical constriction within +/- 0.5 mm in 84% of the samples (21 of 25 canals). However, 96% (24 of 25 canals) were within this range when the combination of Root-ZX and radiographs was used. We noted no statistical significance between these 2 methods (P > .05). Using a Root ZX Electronic Apex Locator combined with radiographs is recommended for the determination of working length, although there was no statistical significance between those 2 groups in this study.

A comparative study of three periapical radiographic techniques for endodontic working length estimation

To compare the diagnostic quality of endodontic working length estimation films produced using film holders with those taken using the bisecting angle technique and to assess the level of acceptance of film holders by operator and patient. Five post-graduate and 20 final year undergraduate students attending a UK Dental School produced working length radiographs using either the paralleling or the bisecting angle technique. The paralleling group used one of two film holders, the Endoray II or the XCP Endodontic Instrument, on alternate patients. An assessment of the ease of use of the device and the patients' views on the comfort of the examination were recorded. Each radiograph was examined simultaneously by two assessors, scored for film faults and diagnostic acceptability. Statistical data was derived using the Mann-Whitney U test and Cohen's kappa. The rates of unacceptable radiographs for the XCP Endodontic Instrument, Endoray II and the bisecting angle techniques were 12.2%, 21.4% and 48.6%, respectively. The combined percentage of unacceptable paralleling technique films (16.7%) was highly significantly different (P < 0.001) when compared with the bisecting angle technique (48.6%). The paralleling technique produced a significant reduction in incorrect vertical angulation (P < 0.001), cone cutting (P < 0.001) and incorrect film placement (P < 0.001). Film holders were rated either excellent or good in 90% of examinations by operators and 47.5% of patients reported no discomfort. These results support the use of the film holders for endodontic working length estimation.

A comparison between in vivo radiographic working length determination and measurement after extraction

A comparison between in vivo radiographic working length determination and measurement after extraction

The role for ‘reminders’ in dental traumatology: 2. The effectiveness of a reminder stamp compared with the current clinical practice for documenting the diagnostic working length

The aim of this study was to establish if a predesigned prompt in the form of a reminder stamp placed in a patient's dental records is more effective for recording the essential details of a diagnostic working length compared to the current practice without any specific prompts. Following a pilot study of current practice, a stamp was introduced. Twelve months following the introduction of the stamp, 198 patient records were examined, where endodontic treatment had been carried out mainly for traumatic injuries. The following parameters were specifically investigated whether a radiograph had been taken to establish working length and was it available for examination, whether the working length was recorded in the notes and whether a reference point for the measurements was given. The working length was conventionally recorded by 127 notes, whereas 71 used the stamp. A working length radiograph was taken and a working length recorded for 95% of the cases where no stamp had been used, compared to 100% of the stamp group. Where no stamp had been used only 83% of working length radiographs were available compared to 100% of the stamp group. Interestingly, a reference point from where the working length had been measured was only recorded in 5% of the cases where the stamp had not been used compared to 94% using the predesigned stamp. This result was statistically significant using a chi-squared test (P < 0.001). The stamp was generally more effective than the conventional method of recording the working length for endodontics.

A Comparison between In Vivo Radiographic Working Length Determination and Measurement after Extraction

The purpose of this study was to compare the difference between the in vivo working length established by viewing a periapical radiograph and the in vitro measurement from the file tip to the apical foramen of the extracted tooth. Twenty-six canals from teeth that had been treatment planned for extraction were accessed under rubber dam isolation. The coronal portion of each canal was flared using Gates Glidden drills, and a K-type file was inserted down the canal until an electronic apex locator indicated that the file had reached the apex. A size 20 K-type file was locked into place with glass ionomer cement at this position. A radiograph was exposed and the tooth was extracted. Each tooth was viewed using a videomicroscope at 30× original magnification, and the distance from the file tip to the most coronal aspect of the major foramen was measured. Six examiners viewed each radiograph and assessed the working length of each canal. χ 2 analysis of the data revealed a significant difference (p < 0.01) between the estimation of working lengths and the microscopic measurements. The examiners overestimated the distance between the file tip and the apical foramen of the tooth when the file was placed short, and underestimated the distance when the file was placed long. In conclusion, when the file is short it is actually closer to the apical foramen than it appears radiographically; when it is long it is actually longer than it appears radiographically.

Comparison between two methods of working length determination and its effect on radiographic extent of root canal filling: a clinical study [ISRCTN71486641

BackgroundObtaining a correct working length is critical to the success of endodontic therapy. Different methods have been used to identify this crucial measurement. The Aim of this clinical study was to compare the effect of working length determination using apex locator alone or in combination with working length radiograph on the apical extent of root canal filling.MethodsA total number of 66 patients, 151 canals were randomized into two groups, In group (I) working length was determined by apex locator alone, while in group (II) working length was determined by apex locator confirmed by working length radiograph, length of obturation was assessed, and the total number of radiographs was recorded. The data were analyzed using SAS system and T. tests were carried out. Statistical significance was considered to be P ≤ 0.05.ResultsSixty seven canals in group I were treated with a mean distance from the tip of root canal filling to radiographic apex -0.5 mm ± 0.5 and a mean of a total number of radiographs of 2.0, while in group II eighty four canals were treated with a mean distance from the tip of root canal filling to radiographic apex -0.4 mm ± 0.5 and a mean of a total number of radiographs of 3.2. There was no statistically significant difference in the mean distance from the tip of root filling to radiographic apex between group I and group II (P > 0.05).ConclusionThe practice of using electronic apex locator in the determination of working length is useful and reliable with no statistical difference of the radiographic extent of root canal filling when using apex locator alone or in combination with working length radiograph. Under the clinical conditions of this study, it is suggested that the correct use of an apex locator alone could prevent the need for further diagnostic radiographs for determination of working length. This method can be useful in patients who need not to be exposed to repeated radiation because of mental, medical or oral conditions.

The Ability of Root ZX Apex Locator to Reduce the Frequency of Overestimated Radiographic Working length

The aim of this in vitro study was to evaluate the ability of the Root ZX device to avoid instrumentation beyond the apical foramen in premolars after conventional working length radiography. Thirty extracted premolars with 43 root canals were subjected to radiographic and electronic working length determination. Radiographic working length determination resulted in overestimation in 51% of the root canals, although the measuring file tip was located to be 0 to 2 mm short of the radiographic apex. Electronic working length measurements with the Root ZX reduced the percentage of overestimation to 21%. In 6 root canals (14%), both radiographic and electronic working length measurements led to overestimation. It is concluded that complementing radiographic working length determination with electronic apex locator measurements may help to avoid overestimation beyond the apical foramen in premolars.