Lateral Condensation Of Gutta-percha Research Articles

Comparison of laterally condensed and low-temperature thermoplasticized gutta-percha root fillings

The aim of this study was to evaluate and compare the radiographic quality and sealability of root fillings in extracted human teeth using lateral condensation of gutta-percha or low-temperature thermoplasticized gutta-percha (Ultrafil). One hundred freshly extracted human, mature singlerooted teeth were divided into four identical groups of 25 teeth on the basis of root canal shape. The root canals of two groups were prepared in such a way to produce a relatively parallel shape with little or no flare toward the coronal orifice. The root canals of the other two groups were prepared in such a way as to produce a canal shape that was deliberately more flared to ensure that they were wider at the orifice than at the end point of the preparation. All root canals were flushed with 17% EDTA solution and 2.5% NaOCl to remove the dentinal smear layer. The canals of one flared group and one parallel group were obturated using cold lateral condensation, and the canals of the other two groups were obturated using low-temperature thermoplasticized gutta-percha. The sealability of each technique was assessed by a dye penetration method. The radiographic quality of obturation was determined for each canal using a 4-point scale. Canals filled with thermoplasticized gutta-percha had significantly less apical dye penetration than those obturated by lateral condensation (p < 0.001). Lateral condensation achieved significantly better scores for radiographic quality than thermoplasticized gutta-percha from both the buccolingual (p < 0.005) and mesiodistal views (p < 0.001). Low-temperature thermoplasticized gutta-percha root fillings were associated with significantly more apical extrusion of sealer (p < 0.001) and gutta-percha (p < 0.005). Under laboratory conditions the low-temperature thermoplasticized gut

Leakage Along Apical Root Fillings in Curved Root Canals. Part I: Effects of Apical Transportation on Seal of Root Fillings

Occurrence of apical transportation (AT) may complicate the root filling procedure and result in a compromised seal. In part I of this study, human mandibular premolars with single, curved (21 to 39 degrees), or straight canals were prepared by Lightspeed or a step-back hand filing technique. An AT index was determined using a double exposure radiographic technique. The prepared canals were obturated using lateral condensation of gutta-percha. Leakage along the apical 3 mm of root filling was measured with a fluid transport model. After hand filing, AT and perforation occurred in 87% of the curved canals. The AT indices were > or = 0.4 mm. After Lightspeed preparation, AT occurred in only 19% of the curved canals. The hand filing/curved group leaked statistically significantly more than the hand filing/straight and Lightspeed/curved groups (p = 0.002). We conclude that occurrence of AT is a factor that negatively influences the apical seal when curved canals are obturated by lateral condensation of gutta-percha.

Coronal leakage of two root canal sealers containing calcium hydroxide after exposure to human saliva

This in vitro study evaluated the coronal leakage of human saliva into root canals filled by lateral condensation of gutta-percha using two root canal sealers containing calcium hydroxide. Obturated canals with gutta-percha and either Sealapex of Sealer 26 were mounted in an apparatus and then exposed to saliva. The number of days required for total recontamination of the root canal was recorded. Evaluation was conducted for 60 days. Thirty-five percent of the specimens of the Sealer 26 group showed entire recontamination at 60 days. Eighty percent of the root canals obturated with Sealapex showed complete recontamination at 60 days. Sealer 26 presented significantly less leakage than Sealapex (p < 0.01).

Stress analysis during root canal filling by vertical and lateral condensation procedures: a three-dimensional finite element model of a maxillary canine tooth.

To investigate the distribution of stresses that occur in a maxillary canine tooth during vertical and lateral condensation of gutta-percha in the root canal. An elaborate three-dimensional finite element model of a maxillary canine tooth was developed for the purposes of stress analysis. A sample stress analysis was also performed to demonstrate the variations in stress values that occur between different solutions of the same problem. A 3D finite element analysis was performed on a maxillary canine tooth model which was created using the dimensions of computer tomographic scans of a cadaveric maxilla as reference. If the manual operations of the endodontist are transcribed to the software by considering the finite size of the plugger or the spreader, then the maximum stresses generated in the dentine are much smaller than the reported tensile strength of this material. The causes of the fractures in the dentine reported by previous investigators must be traced to conditions which were not considered in this study. These include aspects of modelling, which is the most important single parameter on which the final results depend. Stresses calculated by means of the complicated 3D model appear to agree with those recovered from a simpler 2D idealisation.

As time goes by: Forgetting and remembering in 9- and 10-month-olds

The frequency of the creation of apical dentin plugs in unifected monkey teeth with vital pulps and their effect on healing of filled and unfilled canals were investigated. Two male monkeys, one Macaca mulattaand one Macaca speciosa, were used for a 9-and 12-month study.Forty-three root canals in 33 teeth prepared 0.5 to1 mm from the radiographic apex were studied histologically. Thirty-one experimental canals were not filled after instrumentation and 12 control canals were filled by lateral condensation of gutta-percha and sealer after instrumentation.After both 9 and 12 months, there was a less than23% incidence of inflammation associated with the periapices of the experimental group that had his-tologically apparent apical dentin plugs. Similarly, there was a less than 18% incidence of inflammation associated with the periapices of the control canals that had plugs. Inflammation was much more common (90%) in both the experimental and control canals without plugs. Statistical analysis showed that canals with plugs (experimental and control) had less inflammation than canals without plugs.

Apical sealing using two thermoplasticized gutta-percha techniques compared with lateral condensation

This study was conducted to compare the apical sealing capacity of three filling techniques, a multiphase gutta-percha obturation technique, JS Quickfill, and lateral gutta-percha condensation. A four-stage stepback preparation was executed with circumferential filing in a total of 70 recently extracted permanent maxillary incisors and canines. Three experimental groups (20 teeth in each group) and two control groups (5 teeth in each group) were formed at random. Each experimental group was obturated with a different technique. The positive control group was not obturated. In the negative control group, the whole root was covered with two full nail varnish layers. Teeth were immersed in India ink for 48 h, demineralized, cleared with methyl salicylate, and examined with a stereomicroscope. None of the specimens obturated with the multiphase gutta-percha obturation system showed any penetration of India ink beyond the end of the preparation. In the groups of teeth obturated by JS Quickfill or lateral gutta-percha condensation, leakage was detected in one specimen from each group. No statistically significant differences were seen among groups. We conclude that the newer thermoplasticized filling techniques can be used successfully to obturate root canals in large, straight roots.

Sealing properties of a new epoxy resin‐based root‐canal sealer

In this study a new epoxy-resin-based endodontic sealer, AH Plus, was tested in vitro for apical leakage. The conventional sealer AH26, for which information is already available, was used as the control. The root canals of 72 single-rooted teeth were prepared biomechanically using a stepback technique before lateral condensation of gutta-percha with one of the two sealers. Teeth were immersed in 5% methylene blue dye for 2, 4 or 10 days. The roots were split longitudinally so that the extent of dye penetration could be measured with a stereomicroscope. The mean extent at 2 days was 0.4 mm for AH26 and 1.4 mm for AH Plus. Neither material produced a complete apical seal and leakage increased with the duration of immersion in dye. The differences between observation periods as well as between materials with respect to dye penetration were statistically significant ANOVA, (P < 0.005).

Prevalence of teaching apical patency and various instrumentation and obturation techniques in united states dental schools

Maintaining an open apex beyond the apical constriction with an endodontic file during canal instrumentation is a concept that has been advocated by several authors and clinicians. To ascertain the prevalence of teaching the patency concept as well as various instrumentation and obturation techniques in the United States dental schools, a survey was conducted. Forty-eight out of a total of 53 dental schools (91%) responded to the survey. Results indicate that 50% of the schools surveyed teach the concept of patency to their undergraduates or graduates or both; 83% teach a step-back instrumentation technique; and 89.6% teach lateral condensation of gutta percha as their primary obturation technique.

An in vitro comparison of apical microleakage after obturation with JS quick-fill or lateral condensation

Thirty extracted human single-root teeth were instrumented to #45 file size while creating a continuous coronal taper. Canals were obturated with Roth 801 sealer and either JS Quick-Fill or lateral condensation of gutta-percha. Mean apical linear microleakage of India Ink was evaluated in cleared teeth using a stereomicroscope. Significantly less leakage (p < 0.1) occurred with lateral condensation than with JS Quick-Fill.

A comparative study of the sealing ability of two root canal obturation techniques

A comparison was made of the ability of two root canal obturating techniques to prevent dye microleakage: gutta-percha lateral condensation and mechanically plasticized gutta-percha (JS Quick-fill). Twenty central incisors were prepared and obturated by each technique. After rendering the teeth transparent, linear dye penetration was found to be 0.48 and 0.52 mm, respectively. The difference between the two techniques was not significant. As for the distribution of the sealing cement (AH26) in the teeth obturated with JS Quickfill, the cement was located in the most peripheral zone of the obturation alongside the dentinal walls, whereas the gutta-percha was found in the central part of the canal obturating material.

PC 27 Apical and coronal microleakage of two root canal filling techniques

Root Canal Filling Techniques. M. Carter, S. Frost, V. Karapanou*, C. Pastan, M. Goldman, R. White, Tufts University, Boston, MA This study assessed apical and coronal dye leakage of a single gutta percha cone, resin sealer, filling technique compared with lateral condensation of gutta percha and sealer. 68 single canal teeth were instrumented to an apical size of 40 using a crown-down, step-back technique. To remove the smear layer, final irrigation with 15% E.D.T.A. was followed by 5.25% NaOCl. The teeth were then randomly divided into 2 groups of 30 and 4 controls. 30 samples in Gr. A were filled using lat. condensed g.p. and Z.O.E. sealer. A single fitted cone and resin sealer were used to fill the 30 teethin Gr. B. (+) controls were filled with loosely fitted g.p. w/out sealer. (-) controls were covered with sticky wax. Wax covered all but the apical foramen in 15 teeth from Gr. A and B. Wax covered all surfaces except the coronal access of the remaining 15 teeth in each group. After 7 days, all samples were placed in 2% methylene blue under a vacuum. The samples were then split longitudinally and measured for leakage by 2 examiners. Inter-examiner reliability correlated_. A students' T test demonstrated that the resin sealer demonstrated siqnificantly less coronal leakaqe than lateral condensation. There was no siqnificant difference in the apical leakaqe.

A new non-instrumental technique for cleaning and filling root canals.

The aim of this in vitro study was to test the ability of a novel non-instrumental technique to prepare and obturate root canals. Cleaning of the root canal system was achieved with a device which was able to develop, under reduced pressure, controlled cavitation. The same device was used for proper drying and subsequent obturation of the root canal system. A total of 55 freshly extracted molars with 120 canals were treated either by the step-back technique and lateral condensation of gutta-percha and AH26 as a sealer or by the new device. The teeth were then sectioned horizontal to the long axis of the root canal and examined by light microscopy. The cross-sectional area, area with residual pulpal tissue and voids were assessed morphometrically. Overall, the treatment with the new device resulted in similar cleanliness and obturation quality when compared with the control group. Total treatment time using the new non-instrumental technique, however, was less than half of that using hand instrumentation.

Comparison of apical leakage between Ketac Endo sealer and Grossman sealer

Forty-eight extracted human teeth were prepared for study to compare ketac Endo cement with Grossman's cement in preventing leakage of a dye. Four groups were formed: (1) Grossman's sealer with a single gutta percha cone; (2) Grossman's sealer with lateral condensation of gutta percha; (3) Ketac Endo sealer with a single cone of gutta percha; and (4) Ketac Endo sealer with lateral condensation of gutta percha. The teeth were immersed in the dye for 10 days, after which they were rinsed in running tap water and cleared for observation. In the groups of teeth evaluated by three individual evaluators, the results consistently showed less leakage with glass ionomer sealers (groups 3 and 4) than with the Grossman's sealers (groups 1 and 2). The best results were noted when Ketac Endo sealers were used with lateral condensation.

RS 7 Reliability of apical dye sealability studies with and without vacuum removal of air inclusions

The reliability of two commonly used methods of sealability testing, dye leakage under normal atmospheric pressure and dye leakage in a vacuum, was tested using a repeated studies design. Forty extracted teeth were instrumented and obturated using lateral condensation of gutta-percha and Sealapex® sealer. One half of the teeth were placed in India ink under normal atmospheric pressure and the other half underwent air evacuation before immersion in the ink. After 24 hours the teeth were removed from the ink and rendered transparent for linear leakage analysis. A second study, repeated within the exact parameters of the first, was performed approximately one month later. MannWhitney U tests indicated that there was no significant difference between the air and vacuum groups or within each group (air or vacuum) between trials, indicating that the methodology is repeatable and that application of vacuum did not enhance the reliability. Most of the teeth placed under vacuum showed evidence of vacuum induced artifacts that may negate the vacuum's value as a research tool.

Dentinal wall adaptation of thermoplasticized gutta-percha in the absence or presence of smear layer: A scanning electron microscopic study

The dentinal adaptation of injected thermoplasticized gutta-percha and thermoplasticized gutta-percha resulting from Ultrafil and Thermafil systems was evaluated by scanning electron microscopy and compared with adaptation obtained with the lateral condensation of gutta-percha. Each method was evaluated with and without the smear layer removed. Scanning electron microscopic observations showed the thermoplasticized gutta-percha resulting from either system to have better dentinal wall adaptation than lateral condensation of gutta-percha in either the absence or presence of the smear layer. In the absence of smear layer, the adaptation of gutta-percha was improved in all groups. Although sealer was used, removing the smear layer was found to enhance the ability of the thermoplasticized gutta-percha to enter the patent tubules.

Obturation of a C-shaped canal using an improved method of warm lateral condensation

Pilot studies conducted by the authors seem to indicate that obturation of a root canal system by the lateral condensation of gutta-percha using an electrically heated spreader results in a more homogeneous mass of gutta-percha than standard lateral condensation. This article describes an improved variation which prevents inadvertent dislodgement of the mass of gutta-percha during the obturation. The authors refer to this technique as "zap and tap" and a case report describes its use to obturate a C-shaped canal system of a mandibular second molar.

An assessment of the plastic Thermafil obturation technique

Adaptation and placement of alpha-phase gutta-percha delivered with a plastic core-carrier, Thermafil, was compared to the lateral condensation of gutta-percha in a specific tooth model. Fifty-one mandibular molar roots with separate canals, patent canal orifices and curvatures greater than 15 degrees were cleaned and shaped with K-files and 2.5% sodium hypochlorite to a size 30 at the apex, and flared with Hedstrom files to create a continuously tapering funnel preparation. Canals were randomly obturated with Sealapex root canal sealer and either alpha-phase gutta-percha on a plastic Thermafil carrier, or standard beta-phase gutta-percha with lateral condensation. Roots were radiographed from the proximal and evaluated by three examiners, based on established criteria for overall material adaptation, apical adaptation, and filling material extrusion. Thermafil provided a statistically significant better overall canal obturation (P < 0.001), while, in the apical third, both techniques were not significantly different (P > 0.05). When the apical orifice was patent there was a significant propensity for the extrusion of filling materials beyond the apex (P < 0.001) with the Thermafil technique.

An in vitro study of the quality of root fillings in teeth obturated by lateral condensation of gutta‐percha or Thermafil obturators

The aim of this in vitro study was to assess the quality of root canal obturation and degree of linear apical dye penetration in teeth root filled with either laterally condensed gutta-percha or Thermafil obturators. A total of 150 teeth with single roots were included in the study. All canals were prepared using a standard step-back technique with anticurvature filing. Radiographs taken of the teeth to show the maximum degree of canal curvature were then exposed and the angle, radius and position of curvature determined. This information about the canals, together with their working length and diameter at end-point, was used to divide the teeth into two experimental and two control groups. A total of eight teeth were excluded because of technical difficulties, 65 were filled with Thermafil obturators, 63 were filled with laterally condensed gutta-percha whilst 14 teeth remained unfilled and acted as controls. Following obturation, the teeth were radiographed in two planes and the technical quality of fill assessed on a four-point scale. All access cavities were then sealed and the teeth immersed in dye for 48 h before being split longitudinally. Linear dye penetration via the apical foramen was then assessed. Canal obturation with Thermafil obturators (0.7 min) was significantly quicker (P < 0.001) than lateral condensation (6.4 min). Apical extrusion of sealer and gutta-percha occurred significantly more often with Thermafil obturators but there was little difference in the technical quality of the fillings and no significant difference in dye penetration. Under the conditions of this study. Thermafil obturators proved a satisfactory alternative to lateral condensation of gutta-percha.

An evaluation of the number of condenser insertions needed with warm lateral condensation of guttapercha

The purpose of this investigation was to determine the number of condenser insertions needed to obturate root canal systems using warm lateral condensation. Forty epoxide blocks with one major and five lateral canals placed at varying angles were used. The blocks received either one, three, five, or seven insertions of the warm instrument. The findings revealed gutta-percha and or sealer in every lateral canal. Cold compaction of the heated gutta-percha produced more material in the lateral canals than did the use of the heated condenser alone. The optimum number of condenser insertions depended upon the position of the lateral canal, the size of the canal, and the bulk of material being heated. The areas of the main canal with a smaller diameter required fewer insertions of the warm condenser to push the gutta-percha into the lateral canals located in those areas.

Endodontic leakage studies reconsidered. Part I. Methodology, application and relevance.

An increasing number of endodontic leakage studies have been published. In the 1990 volumes of Journal of Endodontics and International Endodontic Journal, there was one leakage study to every 4.3 scientific articles. The most popular method was linear measurement of tracer (dye or radioisotope) penetration along a root filling. Comparing some data on linear measurement of dye penetration following the cold lateral condensation of gutta-percha that were published between 1980 and 1990, a high level of variation has been found, although the experimental methods used in these studies were quite similar. In almost all studies evaluating various techniques, the cold lateral condensation technique has been used as a standard control for comparison. The reliability of these results is questionable. The problems with such studies are discussed. It seems that more research should be done on leakage study methodology, instead of continuing to evaluate the sealing ability of different materials and techniques by methods that may give little relevant information.