Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Odontometry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMed1989

An in vitro comparison of five root canal length measuring instruments.

Several new root canal length measuring instruments (RCLMI) have recently been introduced claiming superiority over older systems. The purpose of this study was to compare five models of these instruments with respect to their accuracy under a given set of specified conditions. The five RCLMI tested were: the, Exact-a-pex, the Endocater, the Neosono-D, the Apex Finder, and the Sono-Explorer, Mark III. The conditions tested were the accuracy of the instruments in determining the working length, the consistency of measurement following canal instrumentation and with conductive gutta-percha points in place, and the operation of the RCLMI in the presence of fluids frequently found in root canals during endodontic treatment. An in vitro model was used to test these instruments. A set of 20 teeth was tested using the conditions specified above. All data were compared using the mean difference from the actual canal length of the teeth. The results indicated that there were no significant differences among measurements derived from the five instruments, under the specified conditions. There was a slight variation of the measurements by all instruments when they were used following instrumentation and with the use of conductive gutta-percha points. When fluids were present in the canals, the reliability of the RCLMI depended on the electrical conductivity of the fluid tested. The poorest results were obtained when either sodium hypochlorite or blood were present in the canals.

Dental Instruments↗
PubMed1996

An in vivo evaluation of Root ZX electronic apex locator.

The Root ZX has been introduced recently as a device capable of performing accurately in the presence of sodium hypochlorite, blood, water, local anesthetic, and pulpal tissues. The Root ZX was used to locate the apical foramen in 26 root canals of vital teeth. After extraction of the teeth, a stereomicroscope was used to confirm visually the relationship of the tip of the endodontic file to the apical foramen. The Root ZX located exactly the apical foramen in 17 canals (65.4%), was short in 1 canal (3.8%), and was overextended in 8 canals (30.8%). When a potential error of +/-0.5 mm from the foramen is accepted as a tolerable range for the clinical application of an electronic apex locator, the Root ZX was able to locate the foramen within this range in 25 teeth for a clinical accuracy rate of 96.2%.

Dental Instruments↗
PubMed1996

Comparison of radiographic and electronic working lengths.

The purpose of this study was to compare the ability of radiographic and electronic methods to determine reliably the location of the apical constriction. The working length of root canals in human cadaver teeth was determined by positioning an endodontic file at the apical termination point as indicated by an apex locator. These same teeth were radiographed at various angles with the file in place. The radiographs were evaluated by five examiners to determine a radiographic termination point for each canal. Teeth were extracted and examined histologically to determine the ideal termination point. The deviations of the two experimental termination points from the ideal termination point were compared. The mean of the absolute value of the deviations from the apical constriction for the apex locator was significantly less (p < 0.05) than that for the radiographic method. Thus, the method using the apex locator was slightly more reliable.

Dental Pulp Cavity↗
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↗
PubMed1996

An evaluation of the Canal Master, balanced force, and step-back techniques.

The step-back (SB), balanced-force (BF) , and Canal Master (CM) instrumentation techniques were compared in 53 mesial canals of mandibular molars using two different instrument types: Flex-R and CM. Canal angulation changes from preoperative to postrotary and postinstrumentation were measured using the Schneider technique (ST) and the long-axis technique (LAT). Instrumentation times were recorded, and then the roots were sectioned at 1, 3, and 5 mm from the apex. Measurements were made of the minimal remaining root structures and canal diameter. Rotary instrumentation resulted in a average loss of curvature of 2.37 degrees, as measured by the ST. The ST showed significant changes in canal angulation between CM (-7.74 degrees) and SB (-5.28 degrees) groups, with p < 0.05. LAT showed significant changes for CM versus BF and SB (p<0.001), with a mean change in angulation of -7.69 degrees, -1.68 degrees, and _0.1 degrees respectively. The BF technique (5.5) was significantly faster than either SB (7.1 min) or CM (8.3 min), with p < 0.05. The remaining mesial-distal root structure at all levels was similar among groups.

Analysis of Variance↗
PubMed1997

The degrees and configurations of mesial canal curvatures of mandibular first molars.

The objective of this study was to determine the frequency, degree of curvature, and the configuration of mesiobuccal and mesiolingual root canals of mandibular first molars. The degree of curvature and configuration of root canals creates some technical difficulties to the clinician during biomechanical preparation. Therefore this knowledge is essential for successful endodontic therapy. Six hundred and ninety-seven freshly extracted mandibular first molars were used in this study. After introducing 0.8 to 15 K reamers into the mesial root canals, the teeth were radiographed in buccolingual (clinical) and mesiodistal (proximal) directions. All samples showed curvatures at varying degrees in both views. There was a significant correlation between the degree of primary curvature of mesiobuccal and mesiolingual canals in clinical directions for total samples. When the primary curvature values of the mesial root canals were evaluated in Vertucci classification, the mesiobuccal and mesiolingual canals in Vertucci type VI were found as significantly correlated (r = 0.7173, p < 0.05). A significant correlation was seen between the secondary curvature values of clinical and proximal views of mesiolingual canal in Vertucci type VI (r = 0.9891, p < 0.05). The secondary curvature values in the clinical views of mesiobuccal and mesiolingual canals were found as significantly correlated in Vertucci type II.

Dental Pulp Cavity↗
PubMed1997

Evaluation of a digital radiography to estimate working length.

The working lengths obtained with different methods in single-rooted teeth were compared. An endodontic rule in millimeters and calipers was used as a direct method of measurement (on endodontic files). As indirect methods, measurements were taken from conventional x-rays with calipers and with a digital radiological measurement system. No statistically significant differences were obtained between the direct and indirect methods. Three vertical angulations were taken for the indirect methods (0 degree, 15 degrees, and 30 degrees). No significant differences were found between results for the two indirect methods versus the standard method except for the 30 degrees angulation, which resulted in an impression of a shortened image of about 1.5 mm when using the indirect methods (significance level: alpha = 0.05).

Dental Pulp Cavity↗
PubMed1997

A new engine-driven canal preparation system with electronic canal measuring capability.

A new cordless engine-driven root canal preparation system has been developed that electronically monitors the location of the file tip and the torque applied to the file during all instrumentation procedures. The Root ZX is mounted inside the handpiece to measure the canal length. The engine is driven with a rechargeable battery, and it works more than 40 minutes without a recharge. Nickel-titanium files are used for this preparation system. The file is rotated at 240 to 280 rpms. When the file tip reaches the apical constriction, the revolution of the file can be automatically reversed (Auto-apical-reverse mechanism). If there is too much torque, the rotation is automatically reversed (Auto-torque-reverse mechanism). These automatic functions promise a safer engine preparation of the canal with nickel-titanium files.

Dental Alloys↗
PubMed1998

A SEM study of in vivo accuracy of the Root ZX electronic apex locator.

Twenty-nine unprepared, vital teeth were used to evaluate the accuracy of the Root ZX in locating the root canal foramen. After extraction of the teeth, a scanning electron microscope analyzed the relation of the file tip to the foramen. The sample was divided into two groups (Group A and Group B) according to the presence of a normal apical foramen (along the root main axis) or of a lateral foramen (deviating from the root main axis). With a tolerance level of +/- 0.5 mm, a clinical accuracy rate of 82.75% was recorded in the total sample. With a +/- 1.0-mm tolerance level, an accuracy of 100% was found. The error in locating the apex was significantly smaller in cases with a normal apical foramen (Group A) than in cases with a lateral foramen (Group B) (p < 0.001). An accuracy of 100% at the +/- 0.5-mm tolerance level was registered in Group A.

Dental Instruments↗
PubMed1998

Influence of the concentration of ions and foramen diameter on the accuracy of electronic root canal length measurement--an experimental study.

Investigations on the concentration of cations in human pulp have shown that pathological changes in the pulp lead to changes in the concentration of ions in the tissue. Consequently, its electrophysiological characteristics are changed, which affects the accuracy of electronic root canal length measurements (ERCLMs). The aim of this study was to examine the effect of concentrations of Na+, K+, and Ca2+ cations in medium within the canal and around the tooth, and also foramen diameter, on the accuracy of ERCLMs. The model comprised 21 extracted single-rooted human teeth divided into two experimental groups and one control group, with seven teeth each. Two aqueous solutions of different concentrations of NaCl, KCl, and CaCl2 were mixed with agar. The concentrations of Na+, K+, and Ca2+ corresponded to the results of analyses performed by atomic spectrophotometry on the extirpated human pulps. Agar containing cations was injected into the root canal prepared with a foramen diameter of 0.25 mm. In the control group, the teeth were then completely immersed in agar of the same concentration of cations as the agar inside the canal. In the first experimental group (group 1), the concentration of ions was higher inside the canal, compared with the concentration outside the canal. In the second experimental group (group 2), the order of concentrations was inverse. In all three groups, ERCLMs was performed in the previously described model. Then, the size of the apical foramens was enlarged and ERCLMs repeated at foramen diameters of 0.45 mm and 0.70 mm diameters, respectively. Results indicate that at 0.25 diameters, the most accurate measurements were taken when the concentrations of ions inside the canal were higher than outside the canal (Xdif = 1.39 +/- 1.21 mm) (group 1). At diameters of 0.45 and 0.70 mm, no significant differences were found (p < 0.05) between the experimental groups (error amounted to Xdif = 6.27 +/- 1.47 mm). In the control group measurement, error increased with enlargement of the foramen.

Calcium↗
PubMed1998

An in vivo evaluation of an electronic apex locator that uses the ratio method in vital and necrotic canals.

The purpose of this study was to compare the canal length determined by an apex locator to the apical constriction in both vital and necrotic canals. Informed consent was obtained from patients waiting to have teeth extracted. The teeth were anesthetized, isolated, and accessed. The pulp was considered vital if bleeding was present in the pulp chamber. The Root ZX was used to measure the root canal length. The file was cemented into place, and the tooth was extracted. Twenty-nine teeth containing 34 cemented files were studied, and the distance from the apical constriction was measured. The Root ZX was 82.3% accurate to within 0.5 mm of the apical constriction. The mean distance from the apical constriction was 0.21 mm in vital cases versus 0.49 mm for necrotic cases. There was no statistical difference between the ability of the Root ZX to determine the apical constriction in vital canals versus necrotic canals.

Adult↗
PubMed1998

An evaluation of Ektaspeed Plus film versus Ultraspeed film for endodontic working length determination.

Thirteen teeth in human cadaver sections were accessed and #15 K-files were placed at various lengths in one root canal of each tooth. Using a positioner to ensure duplicate views, radiographs were taken with both Ultraspeed and Ektaspeed Plus X-ray film. Each of the 26 radiographs was coded and then placed in random order. Six endodontic specialists measured the distance from the file tip to the radiographic apex on each film. The results were analyzed by analysis of variance and Cronbach's generalizability theory. It was found that 94% of the variance in measurements was due to differences among the viewers, whereas 5% was due to a combination of viewers and tooth. Only 1% was due to differences between the two types of film. It was concluded that Ektaspeed Plus film may be used for working length radiographs because it requires only approximately 50% of the radiation needed for Ultraspeed film.

Analysis of Variance↗
PubMed1999

An in vitro comparison of two modern apex locators.

Two apex locators were compared regarding their ability to accurately locate the apical constriction in the presence of various canal fluids at different meter readings. Forty-one root canals were filled with 1% NaOCl, 3% H2O2, and 0.9% NaCl, respectively. Electronic working length (EWL) measurements were recorded with the apex locators Root ZX (meter readings: "Apex", "0.5", and "1") and Apit (meter readings: "Apex" and "3"). The deviation of the EWL from the apical constriction was determined. The proportion of measurements within +/- 0.5 mm of the apical constriction ranged between 0.76 and 0.85 for Root ZX at the meter readings "Apex" and "0.5," regardless of the canal contents. Apit consistently displayed shorter measurement values than Root ZX and reached the highest proportions at the meter reading "Apex": 0.59 (1% NaOCl), 0.61 (3% H2O2), and 0.68 (0.9% NaCl). In the presence of NaOCl, Root ZX provides the more accurate EWL measurements at the meter reading "0.5" and "Apex."

Dental Instruments↗
PubMed1999

Direct digital radiography versus conventional radiography for estimation of canal length in curved canals.

A recent development in direct digital radiography (DDR) has made it possible to make additive multiple point (click) measurements of onscreen images. Canal length was examined using four estimation methods: measurement of a conventional D-speed film radiograph, and onscreen DDR allowing two clicks, six clicks, and an unlimited number of clicks of the measuring device. Thirty extracted human teeth with root curvatures ranging from 7 degrees to 47 degrees (Schneider method) were examined. Actual canal length was measured using a millimeter rule and x 2 magnification. Teeth were mounted and prepared for conventional and DDR imaging. Estimated canal length was determined by three board-certified endodontists using each of the four techniques. A two-way analysis of variance indicated that all radiographic techniques resulted in canal lengths that were significantly different from the true canal length, and there was no significant difference between experimental groups, regardless of the canal curvature.

Dental Pulp Cavity↗
PubMed1999

An analysis of canal centering using mechanical instrumentation techniques.

The purpose of this study was to compare canal transportation in moderately curved canals using mechanical instrumentation systems. Mesial roots of mandibular first or second molars were mounted in resin using a modified Bramante muffle system and divided into four groups. The roots were cross-sectioned 2 mm from the working length and at the height of root curvature. Tracings of the canal were made from preinstrumentation slides of the cross-sections. The canals were prepared using ProFile Series 29 rotary instruments, Quantec 2000 rotary instruments, Flex-R files in the Endo Gripper contra-angle handpiece, and Shaping Hedstrom files in the M4 contra-angle handpiece. Tracings of the prepared canals were made onto the originals from postinstrumentation slides. A canal centering ratio was calculated along the line of maximum transportation. Quantec 2000 rotary instruments yielded significantly greater transportation at the apical level when compared with the Profile Series 29 system. There were no other significant differences in transportation at either level. There were no differences in the direction of canal transportation between instrument systems, and the direction of canal transportation was not related to the direction of canal curvature. Canal preparation time was shortest with Profile Series 29 system followed by Flex-R files in the Endo Gripper, Quantec 2000, and Shaping Hedstrom files in the M4.

Dental High-Speed Equipment↗
PubMed1999

Residual thickness of root in first maxillary premolars with post space preparation.

It has been suggested that, to ensure tooth strength, a minimum of 1 mm of root wall thickness should be left after post preparations. The purpose of this study was to determine the instrument diameter that will not affect this measurement in maxillary first premolars. Post preparations were made in 106 teeth with one and two root canals at a working depth equal to the anatomical crown length, with 0.70, 0.90, 1.10, 1.30, 1.50, and 1.70 mm diameter instruments. Sections were cut perpendicular to the long axis of the tooth at the cervical and apical ends of each preparation, and the minimum width of residual root was measured on each wall, at both sites. A binocular microscope with a micrometer eyepiece was used. At the cervical level of the preparation, no group showed a wall thickness < 1 mm. Data for the apical sections was statistically analyzed, and the corresponding confidence limits were calculated with 95% confidence on the mean. The results show that the minimum residual thickness was only preserved when 0.70 mm instruments were used in single-canal roots and when 1.10 mm or smaller instruments were used for two-canal roots. This seemingly anomalous result occurs because fluting on both the mesial and distal sides of the root impinge on single canals, whereas dual canals are buccally or lingually displaced to an area of thicker root diameter.

Bicuspid↗
PubMed1999

Effect of preflaring on Root ZX apex locators.

The Root ZX apex locator is an example of a generation of apex locators that identify the terminus of the canal by measuring a ratio between two electrical impedances. Studies have shown this device to have a high degree of accuracy. However, the manufacturer warns that the performance of these devices is limited by the presence of calcifications and dentinal shaving obstructions. An in vitro study was designed to determine if preflaring of canals would facilitate the passage of files to the apical foramen by eliminating cervical interferences and to see what effect this would have on the performance of the Root ZX apex locator. Thirty-two canals were divided into two groups. Group 1 was not manipulated before use of the Root ZX apex locator and served as control. In group 2, the canals were preflared before the use of the Root Zx apex locator. The working length files were secured in place and measured with the linear measurement tool used by the Visilog 5 imaging program. Results of this study suggest that preflaring of canals will allow working length files to more consistently reach the apical foramen (p = 0.015), which in turn increases the efficacy of the Root ZX apex locator.

Dental Instruments↗
PubMed1999

Apical canal diameter in the first upper molar at various ages.

The shape of root canals cross-sectioned through their roots at 2 mm from their apices and its correlation with the D0 diameter of endodontic instruments was evaluated in 40 first upper molars. The molars were grouped according to age: under 13 yr (children), 18 to 20 yr (adolescents), 30 to 40 yr (adults), and over 50 yr. Evaluation of the root canal diameters revealed that the shapes were predominantly circular in the palatal canal, mostly flat in the mesiobuccal canal, and circular or flat in equal proportions in the distobuccal root. Age does not seem to affect the shape of the canals. Narrowing with age was statistically significant (p < 0.05) for palatal and mesiobuccal canals only. Correlation between the maximum diameter of the canals and the instruments was varied. Even in old age, diameters were observed that would require instruments of a size that would be impossible to use, because one internal diameter would exceed the root's external diameter in a different direction (i.e. intimal buccolingual diameter of #80 and external mesiodistal diameter of #70).

Adolescent↗