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 487 records · Page 27Linked to original sources
PubMed1994

An in vitro test of a simplified model to demonstrate the operation of electronic root canal measuring devices.

This article describes an in vitro test of the accuracy of a model for demonstrating the operation of electronic canal length measuring devices (ECLMDs). The model is made from commercially available gelatin which is mixed with sterile saline solution. Extracted human canine and anterior teeth with fully formed apices had access preparations and complete pulpectomies before drying the canals with paper points. The tooth length was determined with an Exact-A-Pex using the gelatin test model. When the apex locator green light-emitting diode indicated 1.5 mm from the apex, the file length to the nearest 0.5 mm was measured with a rubber stop. This length was compared with the length determined by visualization of the tip of a #10 K-Flex file at the foramen. This method was repeated with the Foramatron IV using the instrument's digital reading of zero as the apex location and root canal length. There was complete agreement as to canal length between electronic root canal measuring devices and visual observations. This indicates that the gelatin test model is an accurate in vitro method of determining canal length.

Cuspid↗
PubMed1994

Radiographic determination of canal length direct digital radiography versus conventional radiography.

This research compared the length determination images produced by Trophy and Regam direct digital radiographic systems with conventional E-speed radiographs. Size #15 K files were placed in the canals of 19 teeth of cadaver specimens and radiographed in a geometrically standardized bench device. Three evaluators estimated the length adjustment necessary to position the file at the apex. The mean estimated adjustment lengths were compared with the true, anatomically determined adjustment lengths. Statistical analysis with analysis of variance and the Student-Newman-Keuls test indicated no significant difference between direct digital thermal print images and conventional radiographs (p > 0.10). Length adjustment estimates with conventional radiographs were significantly more accurate than Regam high-resolution computer monitor images (p < 0.01). Additionally, it was determined that length adjustment estimates were significantly more accurate when the file was placed short of the apex (p < 0.001). The clinical relevance of these differences is discussed.

Analysis of Variance↗
PubMed1996

An in vivo comparison of gradient and absolute impedance electronic apex locators.

Two electronic apex locators based on the gradient (Apit) and absolute (Odontometer) impedance principles were evaluated. Distances of file tips to apical foramina were determined in vivo with the electronic apex locators and subsequently verified after extraction. Mean differences between file tips and apical foramina were +0.14 +/- 0.27 mm and -0.36 +/- 0.71 mm for the Apit and Odontometer, respectively. These differences were statistically significant (p < 0.001). the Apit's and Odontometer's results ranged from +0.85 to -0.65 mm and from +0.35 to 2.45 mm from the apical foramen, respectively. Ninety-three and 73% of the findings for the Apit and the Odontometer, respectively, were within the +/- 0.5 mm range, whereas 100% and 86%, respectively, were within the +/- 1.0 mm range. Thirty-three and 43% of the results for the Apit and the Odontometer, respectively, were 1.0 mm or less coronal to the apical foramen. The Apit tended to yield the more reliable results because of the narrower range.

Adult↗
PubMed1995

Radiovisiography versus conventional radiography for detection of small instruments in endodontic length determination. II. In vivo evaluation.

Radiovisiography was compared clinically to conventional D-speed and E-speed radiographs viewed with X 2 magnification using the mesiobuccal root of maxillary molars of 22 patients. Clarity of size 8 and 10 endodontic file tips in relation to the radiographic apex was the object of comparison. Five images of radovisiography, (original, enhanced, negative-to-positive mode), were compared to D-speed and E-speed radiographs. D-speed radiographs were also compared to E-speed radiographs. D-speed radiographs were statistically superior to all five radiovisiography images. Four of the radiovisiography images were equivalent to E-speed radiographs. D-speed radiographs provided superior recognition of small file tips when compared to E-speed radiographs 100% of the time. Accurate identification of the small file tips was achieved on 95% of D-speed and 70% of E-speed radiographs. With radiovisiography, identification was achieved on 95% of the zoom images in the negative-to-positive mode, 86% of enhanced, 82% of standard zoom, and 77% of the images in negative-to-positive conversion.

Adult↗
PubMed1995

Root canal morphology of human permanent teeth in a Turkish population.

An in vitro study was performed to determine the number and the type of root canals, their ramifications, transverse anastomoses, apical foramina locations, and frequency of apical deltas in a Turkish population. One thousand four hundred human permanent teeth were injected with India ink, decalcified, and cleared after the length of each was measured. The examination of root canal systems of the teeth was based on Vertucci's classification. The findings were used to classify the teeth into four groups. Variable root canal configurations were found in the second premolar and the mesiobuccal roots of first and second molars among the maxillary teeth and in all of the mandibular teeth, except the mandibular second premolar.

Dental Pulp Cavity↗
PubMed1993

An in vivo evaluation of Endex electronic apex locator.

Because of technical problems and hazards of radiation, dentists have desired alternative ways to determine the working length during root canal therapy. Attention has turned to electronic devices for measuring root canal length. Several such devices are now available. They show promise but their accuracy is hampered because moisture in the root canal can result in inaccurate responses. Recently, a new device, Endex, has been introduced, claiming ease of operation and accuracy in moist environments. Ten operators used the Endex to measure 185 root canal lengths (in 99 teeth). Endex measurements were compared with radiographic measurements. The Endex located the apical constriction accurately within +/- 0.5 mm in 89.64% of moist canals.

Adolescent↗
PubMed1992

A three-dimensional study of canal curvatures in the mesial roots of mandibular molars.

The degree and configuration of canal curvature was studied in the mesial roots of 100 randomly selected mandibular first and second molars. The teeth were radiographed in buccolingual (clinical) and mesiodistal (proximal) directions with #8 K files in place. One hundred percent of the specimens demonstrated curvature in both views. No correlation in degree of curvature was found to exist between the clinical and proximal views. Secondary curvature, in a direction opposite to that of the principle curve, was seen more frequently in the proximal view. In the proximal view, canals exhibited greater mean curvature than in the clinical view 38% of the time. Weine type II morphology (two canals, one foramen) demonstrated the greatest range in canal curvature when viewed from the proximal. Coronal flaring with Canal Master rotary instruments to a level just coronal to the curve significantly reduced the severity of curvatures in both views for most cases.

Dental Pulp Cavity↗
PubMed1995

A mathematically based classification of root canal curvatures on natural human teeth.

Testing of root canal-shaping instruments on natural human teeth has many difficulties, because of the different anatomical forms of root canals. There is a lack of an internationally accepted and mathematically based classification of root canal morphology. The aim of this study was to give a mathematical description of root canal forms with the help of differentiated geometrical pattern analysis and computer graphics. The measurements of 433 roots were conducted on isometric radiographs taken from the clinical view. Measured points of the same radiographs were approximated using fourth degree polynomial functions describing the imaginary axis of canals. The classification of root canal morphology on the basis of Schneider's angle differs from the classification of geometrical pattern analysis. Fourth-degree function approximation as a new method for the description of the shape of root canal curvatures seems to be exact and reliably repeatable. This type of classification of root canals is suitable for standardizing test specimens, including natural human teeth used for testing root forms: I (straight), J (apical curve), C (entirely curved), or S (multicurved).

Chi-Square Distribution↗
PubMed1995

In vitro evaluation of the accuracy of several electronic apex locators.

This study describes two tests of the in vitro accuracy of several models of electronic canal length measuring devices (ECLMDs) using a gelatin test model and extracted human teeth with fully formed apices. In part 1, four previously untested ECLMDs were used in dry canals after access and pulpectomy. File lengths with wth file tip just visible at the foramen were compared to ECLMD lengths. Clinically significant ECLMD measurements of > or + 0.5 mm than visual length were noted with two ECLMDs 16.6% and 10% of the time. The other two ECLMDs had no measurements >0.5 mm than the visual measurement. The gelatin test model proved highly accurate with 4 of 6 ECLMDs tested thus far. Part 2 compared the accuracy of a previously tested ECLMD using the gelatin model when taking length measurements with canals both dry and wet with distilled water in them. There was no difference between measurements in wet or dry canals. Irrigation with distilled water may be a clinical aid when using resistance ECLMDs.

Cuspid↗
PubMed1995

Radiovisiography versus conventional radiography for detection of small instruments in endodontic length determination. Part 1. In vitro evaluation.

Radiovisiography is a new intraoral radiographic imaging system. In this in vitro investigation, radiovisiography was compared with conventional radiographs viewed with x2 magnification. Twenty-five extracted maxillary molars were evaluated for clarity of size 8 and 10 endodontic file tips in relation to the radiographic apex. Five images of radiovisiography were compared with D-speed and E-speed radiographs: original, enhanced, negative-to-positive, standard zoom, and zoom in the negative-to-positive mode. D-speed radiographs were also compared with E-speed radiographs. Zoom in the negative-to-positive mode was statistically equivalent to D-speed radiographs (p = 0.264) and superior to E-speed radiographs (p < 0.001). The standard zoom was also superior to E-speed radiographs (p = 0.025). D-speed radiographs were statistically superior to E-speed radiographs; being judged better than E-speed 90% of the time. Accurate identification of the position of the tips of size 8 and 10 files was achieved on all D- and E-speed radiographs with the use of magnification.

Dental Pulp Cavity↗
PubMed1993

Accuracy of the Endex with variations in canal irrigants and foramen size.

Several electronic apex locators (EALs) are currently available. The manufacturer of a new device, the Endex, claims that it is accurate regardless of canal conditions. This study compared the accuracy of the Endex with that of the Exact-a-pex, the Sono-Explorer Mark III, and the Neosono-D SE as to the effects of fluids in the canal and variation in foramen size. Sixty extracted single-canaled teeth were divided into two groups (narrow and wide foramina), depending on whether the apical foramina permitted the tip of a #30 K file to pass through. An in vitro model was used, in which teeth were fitted in test tubes with the roots immersed in 1% agar in phosphate-buffered saline. Root canal lengths were measured in dry canals, then with ethanol, Xylocaine, and sodium hypochlorite in the canals by each electronic apex locator. These lengths were compared with those of the actual root canal lengths. No significant differences were noted among the instruments in dry canals regardless of the foramen size. The endex was generally superior to the other instruments examined in canals containing conductive fluids, especially where the apical foramen was widened.

Chi-Square Distribution↗
PubMed1992

Thickness of cementum/dentin in mesial roots of mandibular first molars.

The mesial roots of 15 human first lower molars, along with the corresponding half of the tooth crown, were studied to determine the thickness of dentin-cementum. A device was developed whereby these could be embedded in resin with a precisely known orientation in space. The roots were radiographed in mesiodistal and vestibular-lingual projections, then sectioned perpendicular to the canal axis in the coronal third. Thickness of dentin-cementum was compared on sections and radiograms; results showed that the amount of hard tissue is effectively about one fifth less than that appearing on the radiogram.

Densitometry↗
PubMed1993

In vivo measurement accuracy in vital and necrotic canals with the Endex apex locator.

Currently apex locators are being used to determine working length. This study was undertaken to see what is actually being measured and if the pulp status, i.e. vital or necrotic, makes a difference in the determination. In this in vivo study, 33 teeth, both vital and necrotic, were measured by the Endex apex locator and then radiographed. After the length determination, the file was cemented to place, the tooth extracted, and then shaved back until the file and the apex were exposed. The position of the file was measured in relation to the apical foramen. Results indicate that all measurements were within a narrow range (-0.86 mm to 0.50 mm). There was no statistical difference in measurements between vital and necrotic canals.

Dental Pulp Cavity↗
PubMed1993

Accuracy of an electronic apex locator: a clinical evaluation in maxillary molars.

Identifying the point of apical termination in endodontic therapy is of indisputable importance. In this study, the accuracy of an electronic apex locator was clinically evaluated in 26 maxillary molar teeth, and comparisons were made to the radiographic and direct anatomical measurements of tooth length. The results indicated that a higher percentage of acceptable measurements were obtained by the radiographic method as compared with the electronic method (88.5% to 73.1%). Additionally, inaccurate electronic estimates were long in every instance. The results of this study do not support the replacement of radiographs with electronic devices in endodontic therapy.

Aged↗
PubMed1992

Root canal configuration of the mandibular first premolar.

One hundred six human mandibular left and right first premolars, previously extracted due to nonrestorable caries, periodontal disease, or orthodontic reasons, were sectioned perpendicular to the long axis of the root starting at the cementoenamel junction. Three-millimeter sections were made with an ultrathin separating disc to the level of the anatomical apex. After 1 day in 5.25% NaOCl, each section was rinsed in phosphate-buffered saline, evaluated with a stereomicroscope, and photographed. The slides were projected and the shape of the canal, incidence of multiple canals, level of bifurcation, and any other variant anatomy were recorded. Seventy-six percent of the premolars demonstrated Type I canals and 24% contained Type IV. The shape of the canals was predominantly oval or round. An interesting finding was the number of C-shaped canals which were associated predominantly with Type IV canal systems. This occurred in 14% of the roots.

Bicuspid↗
PubMed1992

Modified endodontics for lengthy canals.

A review of the dental literature concerning lengths of maxillary cuspids and reports of cuspid gigantism are presented. Endodontic therapy in these cases requires variations and modifications in conventional therapy for successful treatment. A case report is presented which illustrates some of these treatment modifications.

Cuspid↗
PubMed1993

An evaluation of the durability of apex locator insulated probes after autoclaving.

The purpose of this study was to evaluate the durability of insulated probes designed to be used with the Endocater Apex Locator when put through multiple cleaning and autoclaving cycles. The manufacturer has reported that the plastic coating on the probes is reliable with normal use and sterilizable up to a maximum of three cycles. The quality of the seal provided against electrical conductivity by the coating was evaluated using 60 probes of various sizes (10, 15, 20, 25, 40) before and after autoclaving. Visual and electrical field methods were used to detect any leakage in the insulated coating. Defects were detected electronically before they could be detected visually. Statistically significant differences in millimeters of coating lost were found between the original evaluation and after each autoclaving cycle. The size 40 probes lost statistically significantly more coating than did any of the other sizes. The loss of coating seemed to be related to the millimeter markings. The quality of the probes as they came from the manufacturer was excellent; no defects were found in the coating prior to autoclaving.

Dental Cavity Preparation↗