ProTaper System Research Articles

Canal transportation and centering ability of curved root canals prepared using rotary and reciprocating systems

Aim: To evaluate canal transportation and centering ability of Protaper and WaveOne systems in curved root canals by cone-beam computed tomography. Methods: Twenty human molars were randomly divided into two groups according to the system used: Group GP (ProTaper Universal(r)) and group GW (WaveOne(tm)). CT scans were performed before and after the chemo-mechanical preparation on three points: 2 mm, 3 mm and 4 mm from the tooth apex. The cuttings in dentin were measured and results were statistically analyzed. Results: In GP, there was higher percentage in transport at 2 mm and 4 mm toward the mesial wall of the tooth root compared to GW (p<0.05). There was no difference between the systems regarding their centering ability. Conclusions: None of the systems was able to touch all the dentin walls and stay centered during the chemical-mechanical preparation.

Effect of Ultrasonic Activation of Irrigants on Smear Layer Removal

IntroductionThe objective of this study was to evaluate the efficacy of passive ultrasonic irrigation (PUI) with 17% EDTA and 1% NaOCl solutions on smear layer removal. MethodsRoot canal preparations of 32 human teeth were performed with the ProTaper system. Next, they were longitudinally fractured to permit quantitation of smear layer creation from the cervical, middle, and apical thirds of the roots by using scanning electron microscopy. After reassembling the fractured tooth halves, they were divided into 4 groups according to different final irrigation protocols: group1, EDTA + NaOCl; group 2, EDTA with PUI + NaOCl; group 3, EDTA + NaOCl with PUI; and group 4, EDTA + NaOCl, both with PUI. After irrigation, the tooth halves were separated to permit imaging the same areas by scanning electron microscopy, and a percentage of opened dentinal tubules in irrigated areas as a percent of the total area was obtained. The results were submitted to Kruskal-Wallis, analysis of variance, and Bonferroni tests (α = 0.05). ResultsThe cervical third of the samples from all groups showed higher percentage of smear layer removal and open dentinal tubule areas, followed by the middle and apical thirds. Among the irrigation groups, there were statistically significant differences in cervical third between group 2 and group 4 samples, with the highest and lowest percentage of smear layer removal, respectively. ConclusionsPUI by using 1% NaOCl and ultrasonic tip placed within 1 mm of the apical foramen did not show higher efficacy in smear layer removal compared with conventional irrigation.

Comparison of different irrigation activation techniques on smear layer removal: an in vitro study.

The purpose of this study was to evaluate the efficiency of different irrigation activation techniques on smear layer removal. About 80 single-rooted human maxillary central teeth were decoronated to a standardized length.The samples were prepared by using ProTaper system to size F4 and divided into eight equal groups (n = 10) according to the final irrigation activation technique; distilled water was used as an irrigant in Group 1. The other groups were treated with 2.5% NaOCl and 17% EDTA, respectively. Conventional syringe irrigation (CSI) was used in Group 2. Irrigation solutions were activated using passive ultrasonic irrigation (PUI, Group 3), EndoVac apical negative pressure (ANP, Group 4), diode laser (Group 5), Nd:YAG laser (Group 6), Er:YAG laser (Group 7), and Er:YAG laser using with photon-induced photoacoustic streaming (PIPS™, Group 8). Teeth were split longitudinally and subjected to scanning electron microscope (SEM). PIPS showed the best removal of smear layer when compared with PUI, ANP, Nd:YAG, and Er:YAG, but the difference was not statistically significant (P > 0.05). Smear layer scores obtained with PIPS technique were statistically significant different from those of obtained with control, CSI and diode laser groups (P < 0.05). All experimental irrigation techniques except ANP and diode laser removed smear layer more effectively at the coronal and middle levels compared to the apical level (P < 0.05). Irrigation activated/delivered techniques except diode laser have a positive effect on removing of smear layer.

Apically Extruded Debris and Irrigant Using the Revo-S System

Objective: To evaluate the weight of debris and irrigant volume extruded apically from root canals using the Revo-S system compared to that of ProTaper and HERO Shaper systems. Methods: Sixty single rooted teeth were selected and randomly divided into three groups. Each group was assigned to one of the three instrumentation systems: ProTaper, HERO Shaper and Revo-S system. The canals were irrigated with a total of 6 ml of distilled water using a conventional needle. Apically extruded debris and irrigant were collected and measured. Results: The mean and the standard deviation values of dry debris weight with ProTaper system, HERO Shaper system and the Revo-S system were 1.71 ± 0.11 mg, 1.63 ± 0.12 mg and 1.56 ± 0.08 mg respectively and the mean irrigant volume and the standard deviation values were 17.5 ± 2.4 ml, 15.8 ± 1.8 ml and 14.4 ± 3.1 ml respectively. The differences between the three groups were not statistically significant (P > .05). Conclusion: The Revo-S system was comparable to the ProTaper and HERO shaper systems in terms of apically extruded debris and irrigant.

Evaluation of the cleaning efficiency of the isthmus using different rotary instrumentation techniques (In vitro study)

Background: The aims of the study were to evaluate the unclean/clean root canal surface areas with a histopathological cross section view of the root canal and the isthmus and to evaluate the efficiency of instrumentation to the isthmus using different rotary instrumentation techniques. Materials and Methods:The mesial roots of thirty human mandibular molars were divided into six groups, each group was composed of five roots (10 root canals)which prepared and irrigated as: Group one A: Protaper system to size F2 and hypodermic syringe, Group one B: Protaper system to size F2 and endoactivator system, Group two A:Wave One small then primary file and hypodermic syringe, Group two B:Wave One small then primary file and endoactivator system, Group three A: step back technique to size 25 file as MAFand hypodermic syringe, Group three B: step back technique to size 25 file as MAFand endoactivator system . All the roots were sectioned at 2mm, 6mm ,12mm from the apex and studied by histopathological cross section. The degree of cleaning of each section was measured by the use of Autocade 2004 software system. Result :the least uncleaned isthmus surface area at coronal, middle and apical section was found by the Protaper system with endoactivator which represented the mean of the percentage of uncleaned surface area of 16.87%, 14.32% and 9.55% respectively. The system that produced least uncleaned canal wall was by Protaper system with endoactivator at coronal ,middle ,and apical sections of 12.21%, 9.14% and 18.55% respectively . The mean of highest percentage of increased canal diameter which was Protaper system, Wave One system and then step back. The comparison between the groups in the means which showed that the highest percentage of decrease in isthmus area was with the Protaper system, Wave One system and lastly the step back. Conclusions:The Protaper system with endoactivator was the best system in canal and isthmus cleaning.

In vitro evaluation of root canal preparation with two rotary instrument systems - Pro Taper and Hero Shaper.

Background and aimsThe purpose of this study was to compare several parameters of root canal preparation using two different rotary Nickel-Titanium instruments: Pro-Taper (Dentsply Maillefer, Ballagigues, Switzerland) and Hero-Shaper (Micro Mega, Besancon, France).MethodsTwelve extracted maxillary premolars were randomly divided into two groups and embedded into a muffle system. All root canals were prepared to size 25 using Pro-Taper or Hero-Shaper rotary instruments. The following parameters were evaluated: root canal form, centering capacity of the instrument, the presence of residual dentinal debris and smear layer on the root canal walls, working time and the occurrence of intraoperative accidents. Statistical analysis was performed using the chi2 test (p=0.05).ResultsThe majority of the root canals prepared with Hero Shaper (88.89%) and ProTaper (77.78%) showed a round or oval cross-section postoperatively. Superposition of pre- and postoperative photographs of the cross-sections showed that for the coronal third of the root canals the Hero Shaper performed in a superior manner, while for the apical third better results were obtained with the Pro Taper system. Cleanliness of the root canal walls was investigated under the SEM, in the middle third of the canal, using a five-score system for debris and smear layer. For debris Hero Shaper and Pro Taper rotary systems achieved 66.67% and 50% scores of 1 or 2, respectively. The results for the smear layer were similar: cleaner root canal walls were found after preparation with Hero Shaper (66.67% scores 1, 2), followed by Pro Taper (50%). Mean working time was shorter for Hero Shaper (124s) than for Pro Taper (184s); the difference was not significant.ConclusionsWithin the limits of this study, both systems had almost the same cleaning ability and excellent centering capacity.

Micro-computed tomography evaluation of root canal preparation using rotary system and hand instrument in young permanent molars

The aim of this study was to evaluate the shaping potentials of the ProTaper system and nickel-titanium (Ni-Ti) hand-files using micro-computed tomography (μCT) in young permanent teeth. Thirty-second permanent molar teeth extracted from patients 15 to 18 years of age were divided into two groups with 15 samples of each. Group I: were instrumented using the traditional step-back technique by Ni-Ti K-files. Group II were instrumented using the crown-down technique by ProTaper rotary instruments. Before and after root canal preparation, the μCT data were analyzed for the canal volume changes, the percentage differences between these volumes and unprepared surface area ratio of the total surfaces. At all root canals in both groups, the difference between the percentage of the root canal volume before-after preparation was significant (P 0.05). There was no difference between the systems in terms of shaping ability. Considering the shortening session time of the child patient ProTaper system appeared to be beneficial.

Fracture resistance of roots obturated with novel hydrophilic obturation systems.

Aim:Comparative assessment of fracture resistance of roots obturated with three hydrophilic systems — novel CPoint system, Resilon/Epiphany system, and EndoSequence BC sealer; and one hydrophobic gold standard gutta-percha/AHPlus system.Materials and Methods:Ninety freshly extracted, human, single-rooted mandibular premolars were selected. The specimens were decoronated and standardized to a working length of 13 mm. The teeth were randomly divided into six groups (n = 15). In Group A, teeth were left unprepared and unfilled (negative control). Rest of the groups were prepared by using ProTaper system up to a master apical file F3; followed by which Group B was left unobturated (positive control); Group C, novel CPoint System; group D, Resilon/Epiphany system, Group E EndoSequence BC sealer, and Group F gutta-percha and AH Plus. Specimens were stored for 2 weeks at 100% humidity. Each group was then subjected to fracture testing by using a universal testing machine. The force required to fracture each specimen was recorded and the data was analyzed statistically using analysis of variance (ANOVA) test and Tukey's post-hoc test.Results:The hydrophilic obturation systems have shown to exhibit significantly higher fracture resistance as shown by the values in Groups C, D, and E (P < 0.05) when compared with Group F. Within hydrophilic groups there was significant difference between Group D and Groups C and E (P < 0.05), while Groups C and E had no significant difference (P > 0.05).Conclusion:In contrast to hydrophobic systems, hydrophilic systems showed higher fracture resistance in a single-rooted premolar.

In Vitro Comparison of Apically Extruded Debris during Root Canal Preparation of Mandibular Premolars with Manual and Rotary Instruments

Background and aims. During root canal preparation, debris extruded beyond the apical foramen may result in periapical inflammation and postoperative pain. To date no root canal preparation method has been developed that extrudes no periapical debris. The purpose of this study was to identify a system leading to minimal extrusion of debris from the apical foramen. The study was conducted to comparatively evaluate the amount of apical extrusion of debris during root canal preparation using hand ProTaper and GT rotary and RaCe rotary instruments using crown-down technique.Materials and methods. Ninety freshly extracted human single-rooted mandibular premolars were equally assigned to three groups (n=30). The root canals were instrumented using hand ProTaper, GT rotary and RaCe rotary systems. Debris and irrigant extruded from the apical foramen were collected into vials. The mean weight of the remaining debris was calculated for each group and subjected to statistical analysis.Results. ANOVA was used to compare the mean dry weights of the debris extruded in the three groups, followedby post hoc Tukey tests for multiple comparisons the between groups. Highly significant differences were found in the amount of debris extruded among all the groups (P<0.001). The ProTaper group exhibited the highest mean debris weight (0.8293±0.05433 mg) and the RaCe system exhibited the lowest mean debris weight (0.1280±0.01606 mg).Conclusion. All the systems tested resulted in apical extrusion of debris. However, the hand ProTaper files extruded a significantly higher amount of debris than GT and RaCe systems.

Comparison of Endodontic Retreatment in Teeth Obturated With Resilon or Gutta-Percha: A Review of Literature.

Introduction:Retreatment of endodontically treated teeth is a challenge that requires complete removal of the previous filling material. Several techniques are indicated for this procedure. The present review tries to identify the most efficient method for extirpation of Resilon (RS) root fillings and to compare the speed and efficacy of RS and gutta-percha (GP) root filling removal. Methods and Materials: Three trained evaluators conducted a search through three major databases (PubMed, Cochrane Library and Lilacs) over the articles published in the period from 2001 to 2014. The search keywords were Epiphany Sealer, Resilon, Retreatment and Removal Procedure.Results:Twelve articles were included in the final sample (three in vitro studies and nine randomized trials). Conclusion:The ProTaper (manual or rotatory) system in combination with chemical solvents is the most efficient method for removing Resilon root filling. Retreatment of Resilon is more rapid and associated with less remnants of debris.

Root Canal Shaping by Continuous or Reciprocating Rotation : The Protaper System versus the Endo-Eze Tilos System

Root Canal Shaping by Continuous or Reciprocating Rotation : The Protaper System versus the Endo-Eze Tilos System

Comparative Analysis of Canal Centering Ability of Different Single File Systems Using Cone Beam Computed Tomography- An In-Vitro Study

The ability of an endodontic instrument to remain centered in the root canal system is one of the most important characteristic influencing the clinical performance of a particular file system. Thus, it is important to assess the canal centering ability of newly introduced single file systems before they can be considered a viable replacement of full-sequence rotary file systems. The aim of the study was to compare the canal transportation, centering ability, and time taken for preparation of curved root canals after instrumentation with single file systems One Shape and Wave One, using cone-beam computed tomography (CBCT). Sixty mesiobuccal canals of mandibular molars with an angle of curvature ranging from 20(o) to 35(o) were divided into three groups of 20 samples each: ProTaper PT (group I) - full-sequence rotary control group, OneShape OS (group II)- single file continuous rotation, WaveOne WO - single file reciprocal motion (group III). Pre instrumentation and post instrumentation three-dimensional CBCT images were obtained from root cross-sections at 3mm, 6mm and 9mm from the apex. Scanned images were then accessed to determine canal transportation and centering ability. The data collected were evaluated using one-way analysis of variance (ANOVA) with Tukey's honestly significant difference test. It was observed that there were no differences in the magnitude of transportation between the rotary instruments (p >0.05) at both 3mm as well as 6mm from the apex. At 9 mm from the apex, Group I PT showed significantly higher mean canal transportation and lower centering ability (0.19±0.08 and 0.39±0.16), as compared to Group II OS (0.12±0.07 and 0.54±0.24) and Group III WO (0.13±0.06 and 0.55±0.18) while the differences between OS and WO were not statistically significant. It was concluded that there was minor difference between the tested groups. Single file systems demonstrated average canal transportation and centering ability comparable to full sequence Protaper system in curved root canals.

Effect of intracanal medicaments on push-out bond strength of Smart-Seal system.

Aim:To evaluate the effects of calcium hydroxide (CH), triple and double antibiotic pastes (DAPs) on the bond strength of Smart-Seal obturation, C-points with Endosequence Bio-ceramic (BC) sealer to the root canal dentin.Materials and Methods:Sixty-four freshly extracted single-rooted human mandibular premolars were de-coronated and prepared using rotary Pro-taper system with full sequence till F3. The specimens were randomly divided into a control group (without intracanal dressing) and 3 experimental groups that received an intracanal dressing with either CH, DAP, or triple antibiotic paste (TAP) (n = 16). The intracanal dressing was removed after 3 weeks by rinsing with 10 mL 17% ethylenediaminetetraacetic acid, followed by 10 mL 3% sodium hypochlorite. The root canals were then obturated with C-points and Endosequence BC sealer. A push-out test was used to measure the bond strength between the root canal dentin and the obturating system. The data were analyzed using two-way analysis of variance and Tukey post-hoc test.Results:The push-out bond strength values were significantly affected by the intracanal medicaments (P < 0.001), but not by the root canal thirds (P > 0.05). In the middle and apical third, the bond strength of the TAP group was higher than those of the CH and DAP groups (P < 0.05).Conclusions:The DAP and CH did not affect the bond strength of the novel hydrophilic obutrating system. TAP improved the bond strength of Smart-Seal system in the middle and apical thirds.

Effectiveness of different irrigation techniques on smear layer removal in apical thirds of mesial root canals of permanent mandibular first molar: A scanning electron microscopic study.

Aim:The aim of this study was to compare smear layer removal after final irrigant activation with sonic irrigation (SI), manual dynamic agitation (MDA), passive ultrasonic irrigation (PUI), and conventional syringe irrigation (CI).Materials and Methods:Forty mesial canals of mandibular first molars (mesial roots) were cleaned and shaped by using ProTaper system to size F1 and sodium hypochlorite 3% and 17% ethylenediaminetetraacetic acid. The specimens were divided into 4 equal groups (n = 10) according to the final irrigation activation technique: Group 1, PUI; group 2, manual dynamic activation (MDA); group 3, SI; and group 4, control group (simple irrigation). Samples were split longitudinally and examined under scanning electron microscope for smear layer presence.Results:Control groups had the highest smear scores, which showed the statistically significant highest mean score at P < 0.05. This was followed by ultrasonic, MDA, and finally sonic, with no significant differences between them.Conclusions:Final irrigant activation with sonic and MDA resulted in the better removal of the smear layer than with CI.

Effect of advanced irrigation protocols on self-expanding Smart-Seal obturation system: A scanning electron microscopic push-out bond strength study.

Introduction:The aim of this study was to evaluate the effect of different final irrigation activation techniques affect the bond strength of self-expanding Smart-Seal obturation at the different thirds of root canal space.Materials and Methods:One hundred single-rooted human teeth were prepared using the Pro-Taper system to size F3, and a final irrigation regimen using 3% sodium hypochlorite and 17% EDTA was performed. The specimens were randomly divided into five groups (n = 20) according to the final irrigation activation technique used as follows: No activation (control), manual dynamic activation (MDA), CanalBrush activation, ultrasonic activation (UA) and EndoActivator. Five specimens from each group were subjected to scanning electron microscopic observation for assessment of the smear layer removal after the final irrigation procedures. All remaining roots were then obturated with Smart-Seal obturation system. A push-out test was used to measure the bond strength between the root canal dentin and Smart-Seal paste. The data obtained from the push-out test were analyzed using two-way analysis of variance and Tukey post-hoc tests.Conclusions:It was observed that UA improved the bond strength of Smart-Seal obturation in the coronal and middle third and MDA/EndoActivator in the apical third of the root canal space.

A comparative evaluation of the canal centering ability of three rotary nickel-titanium retreatment systems in the mesio-buccal canals of mandibular first molars using computed tomography.

Background:During endodontic retreatment, relative difficulty exists in removing the filling material and maintaining the canal anatomy. Usage of nickel-titanium (NiTi) rotary retreatment instruments is widely accepted, but there is a lack of adequate literature evidence about their canal centering ability.Aim:To compare the canal centering ability of rotary NiTi retreatment systems.Materials and Methods:Mandibular first molars with mesiobuccal canals with canal access angle of 20-40° were used. Canals prepared until ISO 25, 0.06 taper. Obturated with three different techniques lateral compaction, Thermafil, and Resilon/Epiphany. Retreatment was carried using three different systems ProTaper retreatment, Mtwo R and REndo. Specimens were subjected to computed tomography analysis at coronal, middle, and apical third of the root canal preobturation and postretreatment procedure.Statistical Analysis Used:One-way ANOVA and post-hoc Tukey test.Results:No statistically significant difference with three retreatment systems. Variation existed among all the subgroups at the coronal, middle, and apical third of the root canal.Conclusion:All retreatment systems with three obturation techniques showed eccentricity within acceptable limits. REndo, MtwoR showed better canal centering and ProTaper retreatment system showed tendency for eccentric canal preparation, especially in apical third.

Conservation of dentin thickness in the root canals orifice following two preparation techniques

Objective: The aim of this study was to evaluate the amount of dentine removed after canal preparation using ProTaper (PT) and Greater Taper (GT) rotary instruments. Materials and Methods: Twenty extracted human teeth with single roots were selected and sectioned at the level of CEJ. The roots were distributed in two groups (n= 20) using stratified randomization, and prepared under simulated clinical conditions with ProTaper (PT) and Greater Taper (GT) rotary NiTi system. The pre- and post-preparation photographs were traced and superimposed, dentin thickness was measured at the levels of canal periphery, canal area, tooth area, mesial dentin thickness, distal dentin thickness, buccal dentin thickness and lingual dentin thickness both before and after preparation. Results: The thickness of removed dentin was significantly different between the two preparation techniques (p&lt;0.01) at the level of both tooth and canal area with more conservation for GT system while ProTaper system more conservative at buccolingual width than mesiodistal width, and GT system was more conservative at mesiodistal dimension than buccolingual dimension. Conclusion: GT rotary instrumentation prepares root canals has greater conservation of dentine structure on the overall dimensions of the root, while the ProTaper system is more conservative at buccolingual dimension.

Manual and Rotary Instrumentation Ability to Reduce Enterococcus faecalis Associated with Photodynamic Therapy in Deciduous Molars

This aim of this study was to assess the ability of manual or rotary instrumentation associated with photodynamic therapy (PDT) to reduce Enterococcus faecalis using three combinations of light/photosensitizers: toluidine blue O/laser, fuchsin/halogen light and fuchsin/LED. Twenty deciduous molars were selected and contaminated with Enterococcus faecalis (McFarland 0.5 scale). Working length determination was performed by visual method. The teeth were randomly divided into two groups: G1 (n=10): manual instrumentation (Kerr-type files) and G2 (n=10): rotary instrumentation (ProTaper system). The bacteria were collected three times using sterile paper cones compatible with the anatomic diameter of the root canal for 30 s before and after instrumentation and after PDT. The samples were diluted in peptone water, seeded on blood agar plates and incubated in an oven at 37 °C for colony-forming units counting. The decrease of E. faecalis counts after instrumentation and after PDT was compared using the Wilcoxon test, t-test and Kruskal Wallis test. A significant reduction of E. faecalis occurred after manual and rotary instrumentation and after PDT using the three combinations of light/photosensitizer (p<0.05). It may be concluded that both rotary and manual instrumentation reduced E. faecalis. Fuchsin with halogen light or LED irradiation and toluidine blue O with laser irradiation can be used to reduce E. faecalis in root canals of primary molars. PDT can be used as an adjuvant to conventional endodontic treatment.

The Effect of Medicaments Used in Endodontic Regeneration Technique on the Dislocation Resistance of Mineral Trioxide Aggregate to Root Canal Dentin

IntroductionThe aim of this study was to evaluate the effect of calcium hydroxide (CH) and antibiotic pastes, including a mixture of metronidazole and ciprofloxacin, with and without minocycline or cefaclor, on the dislocation resistance of mineral trioxide aggregate (MTA) to root dentin. MethodsEighty single-rooted human mandibular premolars were selected. The teeth were prepared by using the ProTaper system. The prepared teeth were then instrumented to a #6 Peeso reamer to obtain a standard internal diameter of 1.5 mm. The reamers were passed 1 mm beyond apex to simulate immature teeth. The specimens were then randomly divided into a control group (no intracanal medicament was used) and 4 experimental groups that were treated with an intracanal medicament: CH, double antibiotic paste (DAP) with metronidazole and ciprofloxacin, triple antibiotic paste (TAP) with minocycline, or TAP with cefaclor (n = 16). After 3 weeks, the medicaments were removed, and approximately 3 mm of MTA was placed in the coronal third of the canals. A push-out test was used to measure the dislocation resistance between the root dentin and MTA. Data were analyzed by using one-way analysis of variance and Tukey post hoc tests. ResultsThe dislocation resistance values of the CH, TAP with minocycline, and TAP with cefaclor groups were similar to those of the control group (P > .05), whereas the DAP group had the lowest dislocation resistance when compared with the other groups (P < .05). Overall, there was a predominance of cohesive failures between root dentin and MTA. ConclusionsThe results of this study indicate that the application of DAP as an intracanal medicament reduced the dislocation resistance of MTA to root dentin.

Calcium hydroxide fillings in curved canals: influence of apical enlargement using the rotary systems ProTaper, K3, and two hand instrumentation techniques

Objective: This study aimed to analyze the influence of the instrumentation technique (hand or rotary), and apical enlargement on calcium hydroxide (CH) fillings in curved canals. Materials and method: One hundred and ten simulated root canals were divided into eleven experimental groups (G). Canals were prepared with K-Flexofile hand instruments, using either crown-down (GCD 25, GCD 30 and GCD 35) or step-back (GSB 25, GSB 30 and GSB 35) techniques; and with rotary instruments, using either ProTaper (GPT F1 and GPT F2) or K3 (GK3 25, GK3 30 and GK3 35) systems. The apical diameter correspon- ded to 0.20 mm (GPT F1), 0.25 mm (GCD 25, GSB 25, GPT F2 and GK3 25), 0.30 mm (GCD 30, GSB 30, GK3 30), and 0.35 mm (GCD 35, GSB 35, GK3 35). A CH paste, previously colored with blue Indian ink, was injected into the canals using a special syringe. The four sides of the blocks with simulated canals were scanned and the images were transferred to the AutoCAD-2008 software, for assessing the amount (%) of filling in the apical 5 mm (ANOVA; Tukey’s Test; α=0.05). Qualitative analysis was also performed regarding the presence or absence of voids (Chisquare Test; α=0.05). Results: In GSB, there was significant difference between diameters 25 and 30. GSB showed lower amount of filling (P<0.05) than GK3, when the apical diameter corresponded to 0.30 mm. GCD showed lower amount of filling (P<0.05) than the other groups (SB, PT, and K3), when the apical diameter corresponded to 0.25 mm. No significant difference was detected when comparing the four sides of the blocks. Conclusion: Preparation technique and apical diameter had slight or no relevant influence on CH paste filling in simulated curved root canals. Statistical differences found in this study may be clinically irrelevant, since the amount of filling, regardless of preparation technique and apical diameter, was very close or equal to 100%. Keywords: Endodontics. Root canal preparation. Calcium hydroxide.