Alexander Katz

An Evaluation of Endodontically Treated Vertical Root Fractured Teeth: Impact of Operative Procedures

Vertical root fractures of endodontically treated teeth are a frustrating complication that leads to extraction. The aim of the current survey was to evaluate the role of operative procedures in the etiology of this complication. A total of 154 endodontically treated vertical root fractured teeth were cleaned and washed after extraction and maintained in individual vials. Periapical radiographs before extraction, clinical findings and previous operative procedures were recorded. A post was observed in 95 teeth (61.7%), with 66 of these ending at the coronal third of the root. Most were screw posts of the Dentatus type (n = 64) and tapered cast posts (n = 14). A full crown was observed in 118 teeth, and 65 of these (55%) were extracted between 1 to 5 yr after final restoration. In 24 crowned teeth extraction was conducted within 1 yr after restoration and in 28 teeth after >5 years. It was concluded that post placement and root canal treatment are the major etiological factors for root fractures. Because signs and symptoms can appear years after the operative procedures in the root have been completed, coronal restorations would not interfere with the correct clinical diagnosis of vertical root fractures. Frequent recalls are recommended to diagnose vertical root fractures early, especially in susceptible teeth, such as premolars and mesial roots of mandibular molars.

Evaluation of the apical seal produced by a hybrid root canal filling method, combining lateral condensation and thermatic compaction

The apical seal afforded by laterally condensed or thermomechanically compacted gutta-percha has been investigated. The present study measured apical leakage to a dye in roots filled by a combination of the two techniques (hybrid technique). The canals of 40 extracted teeth were endodontically prepared and separated into two equal groups. Lateral condensation with sealer was used in one group. The roots of the second one were filled using the hybrid technique. After immersion in Procion brilliant green, the roots were cleared for measuring the depth of penetration of the dye. The roots filled with the hybrid technique leaked significantly less (p

Radiopacity of Endodontic Sealers: Development of a New Method for Direct Measurement

Radiopacity is an essential attribute of endodontic filling materials. It is important to see clearly the root canal filling to detect its presence, extent, and apparent condensation. National and international standards require a minimal radiopacity equivalent to 3 or 4 mm of aluminum, yet some products made by reputed companies do not meet this requirement. The result may be unjustified downgrading of clinical cases. The purpose of this investigation was 2-fold: to develop a novel and easily reproducible technique for assessing the radiopacity of endodontic sealers and to apply it to measure the opacity of 21 current cements poured in 6- x 1-mm wells. As in the currently recommended technique, the standardized samples are radiographed alongside an aluminum stepwedge but instead of using an optical densitometer to measure the density and then calculate the radiopacity, the image is digitized. The gray pixel value of the test material is compared with the stepwedge, using computer software, to find the corresponding step. The opacity of the samples ranged from 1.6 mm to more than 11 mm of aluminum. The technique can be advanced to a dry, chemical-less variant by using radiation captors, as for periapical X-rays, instead of film.

Comparison of digital with conventional radiography in detection of vertical root fractures in endodontically treated maxillary premolars: an ex vivo study

OBJECTIVE The purpose of the present study was to compare the diagnostic ability of conventional intraoral film radiography and a charged-coupled device (CCD) sensor in detecting vertical root fractures (VRF) in endodontically treated single-rooted extracted human maxillary premolars. STUDY DESIGN The study consisted of 60 extracted single-rooted endodontically treated maxillary premolars: 30 with clinically confirmed VRF (experimental group) and 30 with no VRF (control group). An intraoral CCD sensor and conventional Kodak Insight Film were used. Two observers evaluated the digital and conventional radiographs twice with an interval of 4 weeks. Specificity and sensitivity for each radiographic technique were calculated and subjected to statistical analysis. Kappa values were calculated for intra- and interobserver agreement. Fishers exact test was used to evaluate detection of VRF. The overall differences in sensitivity and specificity between radiographic techniques were evaluated by McNemar test. RESULTS The specificity of the digital system was significantly better (P = .016) for the second observer at the first reading. There were no significant differences in sensitivity and specificity for both observers between the 2 systems for other readings (P > .05). CONCLUSIONS No difference was found between the intraoral CCD sensor and conventional radiography in detecting vertical root fractures for single rooted maxillary premolars ex vivo.

Tooth length determination : a review

Tooth length determination is a crucial step in endodontic treatment. Until the late 1970s, tooth length determination was based mainly on radiographic interpretation. The advent of apex locators, which identify the difference in the electrical resistance between the root canal and the periodontal membrane, ushered in a new era for measuring tooth length. However, the accuracy of these devices has been questioned. Pertinent literature is discussed with the aim of providing information on the development of the concept, techniques, and devices for tooth length determination.

Densitometric measurement of radiopacity of gutta-percha cones and root dentin

National and international standards require that gutta-percha cones be sufficiently radiopaque to be distinguished from natural structures such as dentin and to permit evaluation of the density of the root canal filling. Discs, 1-mm thick, made from 15 commercial and experimental brands of gutta-percha cones, were tested for their compliance with the requirements. The radiopacity of 1-mm thick root dentin slabs was similarly measured with a photo-densitometer. All radiographs were made on D-speed occlusal film and replicated on E-speed film. The mean radiopacity of the gutta-percha discs on D-speed film was 7.26 mm of aluminum equivalent and 7.53 mm on E-speed film, greatly exceeding the minimal requirement of 3 mm. The difference in the values obtained with the two film types was not significant, suggesting that E-speed films may be used for the test. Dentin slabs were uniform in their radiopacity, equivalent to 1 mm of aluminum, confirming previous findings. In view of complaints of insufficient clinical performance, the present minimal requirement for radiopacity of gutta-percha cones seems too low.

Furcation groove of buccal root of maxillary first premolars--a morphometric study.

Furcation grooves on the palatal aspect of the buccal roots of 35 maxillary first premolars, randomly selected, were assessed and found to exist in 97% of the sample. The buccal roots were sectioned into slices, 1 mm thick, and morphometric horizontal and vertical measurements were taken by a Toolmaker Microscope. The slice with the deepest invaginations served as the reference plane. The deepest invaginations were found to be at a mean distance of 1.18 mm from the bifurcation, with a mean depth of 0.4 mm. The canal had a kidney-shaped appearance in cross-section, and the mean distance from the invagination to the canal wall was 0.81 mm. It is thus hazardous to use rotary instruments for flaring these roots and any circular-shaped post space preparation at this level is contraindicated. The outcome of such procedures might be root thinning, perforation, or vertical root fracture, thus causing a poor prognosis.

Residual dentin thickness in mesial roots of mandibular molars prepared with Lightspeed rotary instruments and Gates-Glidden reamers

OBJECTIVE We sought to measure the residual dentin thickness (RDT) in the mesial roots of mandibular molars after instrumentation with Lightspeed and Gates-Glidden rotary instruments. Study design Thirty extracted, untreated human mesial roots of mandibular molars were separated from the distal roots and embedded in clear polyester resin. The roots were cut horizontally at 1, 4, and 7 mm short of the anatomic apex. The diameter of each mesiobuccal canal was measured by using a stereo measuring microscope at each level in the buccolingual and mesiodistal directions. The dentin thickness was measured in each level in the mesial, distal, buccal, and lingual directions. Sections were reassembled with a muffle. The canals were enlarged to the working length with Lightspeed rotary instruments, of which the average size used was a No. 50 file. The coronal third was flared with No. 2 Gates-Glidden reamers. Slices were separated again, and the RDT and canal diameters were measured. RESULTS The minimal measured RDT after instrumentation at the 1-, 4-, and 7-mm levels was 0.70 +/- 0.28 mm, 1.04 +/- 0.18 mm, and 1.09 +/- 0.19 mm, respectively. The average diameter of the canals after instrumentation at the 1-, 4-, and 7-mm levels was 0.50 +/- 0.04 mm, 0.52 +/- 0.05 mm, and 0.74 +/- 0.08 mm, respectively. The canal diameter did not exceed one third of the root diameter at all levels. CONCLUSIONS Root canal preparation of mandibular mesial roots with Lightspeed instruments to No. 50 in the apical third and Gates-Glidden reamers to No. 2 in the coronal third does not significantly decrease the RDT.

Efficacy of apical seal of Engine Plugger condensed root canal fillings—Leakage to dyes

A new rotatory instrument, the Engine Plugger, that is claimed to be less fragile than the McSpadden Compactor, has been introduced since the recognition of thermomechanical compaction as a valid technique for root canal filling. The purpose of this study was to test the efficacy of the apical seal afforded by the Engine Plugger in comparison with that of an established technique, lateral condensation. Eighty roots with round canals prepared to size 45 were randomly divided into two groups: one compacted with the Engine Plugger (Group 1) and the other with the lateral condensation technique (Group 2). AH-26 sealer was used in half the specimens. Four additional roots served as controls. The roots were cleared following immersion in Procion brilliant green, and the maximal depth of penetration of the dye was measured with a stereomicroscope. Severe leakage occurred in both groups when sealer was not used (mean depth: 3.17 mm in Group 1; 4.3 mm in Group 2). Addition of sealer reduced leakage significantly (p less than 0.001). There was no statistically significant difference in the depth of penetration of the dye between the two groups when AH-26 was used, although a trend in favor of the Engine Plugger method (0.15 mm versus 0.425 mm for lateral condensation) was noted.

Life and AH26 as sealers in thermatically compacted gutta-percha root canal fillings: Leakage to a dye

Calcium hydroxide-containing root canal sealers may encourage apical obturation by cementum. Hard-setting bases with calcium hydroxide induce calcification, but set too quickly to permit lateral condensation of gutta-percha. Since thermatic compaction requires less time than lateral condensation, the possibility of using this method with Life as a sealer was investigated. Seventy roots were prepared and filled with gutta-percha using the Engine Plugger for thermatic compaction. In one group of 20 Life was used as a sealer. AH26 was used in another group of 20. The remainder served as controls. Leakage was tested by linear penetration of Procion B Blue dye measured after clearing the teeth. In the Life group the mean dye penetration was 0.575 mm versus 1.025 mm in AH26, but the difference was not statistically significant. The results indicated that Life could be used in thermatic compaction of gutta-percha and that it provided a seal comparable to that obtained with AH26.