Temperature change within gutta-percha induced by the System-B Heat Source

Venturi, M.; Pasquantonio, Guido; Falconi, Mirella; Breschi, Lorenzo

doi:10.1046/j.1365-2591.2002.00553.x

Cited by 52 publications

(68 citation statements)

References 20 publications

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“…The root canals were rinsed, dried and a cotton pellet was fixed on the external surface to cover the apical foramina and simulate the clinical apical patency conditions (12). Specimens were then immersed in a base of impression material (Express Putty, 3M/ESPE, St. Paul, MN), connected to a grid, and immersed in a thermostatic bath of water at 37°C, so that the access of every pulp chamber was above the water surface (26).…”

Section: Methodsmentioning

confidence: 99%

“…Specimens were randomly divided in two groups (A and B) of thirty roots, treated as previously described, and subsequently connected to a grid and immersed in a thermostatic bath of water at 37°C (26).…”

Section: Filling Techniquesmentioning

confidence: 99%

“…Three major reasons may be involved in determining these results: the viscosity of the gutta-percha that allows to better fill large spaces compared to tight ones; the small temperature increases that can be obtained in the apical gutta-percha also using electric heat-carriers (9,26) and finally the thermo-mechanical compaction of the gutta-percha that could be more effective in the middle and coronal thirds (11,12). In fact the "vertical compaction with apical backfilling" involves the placement of a condensed filling plug at apical level to allow a protracted and effective compaction without risk of apical extrusion (12) up to 5 mm from the apex.…”

Section: Shape and Diameter Of Lateral Canals May Also Influence Cleamentioning

confidence: 99%

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An In Vitro Model to Investigate Filling of Lateral Canals

Venturi

Lenarda

Prati

et al. 2005

Journal of Endodontics

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Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of group 1 were filled with Schilder's technique, canals of group 2 were filled with vertical compaction with apical backfilling. Stereomicroscopic analysis of lateral canal filling revealed lower filling rates in apical canals compared to coronal ones and higher filling rates with "vertical compaction with apical backfilling" compared to Schilder's group. The tested procedure appears to be a reliable technique to obtain standardized lateral canals and to compare filling procedures. (5), other studies demonstrated a their potential pathogenicity after healing of periradicular lesions in relation with full filling of lateral canals (6 -8). Key WordsThe capability of an endodontic filling technique to ensure obturation and sealing of thin and irregular ramifications is an important clinical parameter, and may represent a favorable aspect of the filling technique. Among different techniques proposed over the years, the Schilder's technique has been shown to effectively fill lateral canals (9). Brothman (10) demonstrated that vertical compaction of warm gutta-percha approximately doubled number of filled lateral canals if compared to gutta-percha lateral compaction. Recently, the capability of filling lateral canals of a new obturation technique (11, 12) has also been investigated.Several in vitro models have been proposed to compare results of different filling techniques. For this purpose artificial lateral canals were created using various methods and resulting in different shape and size. Wong et al. (13) and Tagger and Gold (14) used a split and hinged hard metal model containing a main canal with extensions mimicking lateral canals, while other authors proposed resin blocks with a main curved canal with lateral ramifications (15-17). Tooth embedded in acrylic block was also proposed (18 -21): the resin block containing the tooth was longitudinally sectioned and root canal irregularities were subsequently produced with a one-half round bur, before re-approximate and secure the two halves. Goldberg et al. (22) created simulated lateral ramifications with reverse taper in human teeth by using a #15 engine reamer to drill into the center of the canal. Similarly Dulac et al. (16) used a #20 K file to fabricate lateral canals in epoxy resin blocks in which simulated root curved canals had been previously mechanically prepared. All these models of lateral canals have diameters greater than natural ones. In fact previous studies showed that 61.3% lateral branches in mandibular incisors and 70.1% in maxillary central incisors had thickness less than #10 reamer (23,24).Considering the high number of in vitro techniques proposed ov...

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Section: Methodsmentioning

confidence: 99%

Section: Filling Techniquesmentioning

confidence: 99%

Section: Shape and Diameter Of Lateral Canals May Also Influence Cleamentioning

confidence: 99%

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An In Vitro Model to Investigate Filling of Lateral Canals

Venturi

Lenarda

Prati

et al. 2005

Journal of Endodontics

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“…Without sufficient compaction, voids will be created inside the obturated canal. 10 When too much excessive force is delivered to the stiffened material, it will result in iatrogenic vertical root fractures. 9 A combination of controlled compaction stress and timely manipulation needs to be in accordance with the material consistency, particularly when the material rapidly undergoes phase transition with decreasing temperature.…”

Section: Discussionmentioning

confidence: 99%

Rheological characterization of thermoplasticized injectable gutta percha and resilon

Chang

Baek

Lee

2011

J Korean Acad Conserv Dent

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Objectives:The purpose of this study was to observe the change in the viscoelastic properties of thermoplasticized injectable root canal filling materials as a function of temperature and to compare the handling characteristics of these materials. Materials and Methods: Three commercial gutta perchas and Resilon (Pentron Clinical Technologies) in a pellet form were heated in the Obtura-II system (Obtura Spartan) at 140℃ and 200℃, and the extrusion temperature of the thermoplasticized materials was measured. The viscoelastic properties of the materials as a function of temperature were evaluated using a rheometer. The elastic modulus G', viscous modulus G'', loss tangent tan δ , and complex viscosity η * were determined. The phase transition temperature was determined by both the rheometer and a differential scanning calorimeter (DSC). The consistency of the materials was compared under compacting pressure at 60℃ and 40℃ by a squeeze test. Results: The three gutta perchas had dissimilar profiles in viscoelastic properties with varying temperature. The phase transition of softened materials into solidification occurred at 40℃ to 50℃, and the onset temperatures obtained by a rheometer and a DSC were similar to each other. The onset temperature of phase transition and the consistency upon compaction pressure were different among the materials (p < 0.05). Resilon had a rheologically similar pattern to the gutta perchas, and was featured between high and low-flow gutta perchas. Conclusions:The rheological characteristics of the thermoplasticized root canal filling materials changed under a cooling process. The dissimilar viscoelastic properties among the materials require different handling characteristics during an injecting and compacting procedure.

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“…This depends on heating temperature, application time, and insertion depth (13). Smith et al (14) showed that the heat must be applied to within 3 mm short of WL to soften the master cone and ensure good adaptation to the canal wall.…”

Section: Discussionmentioning

confidence: 99%