Cervical Thirds Research Articles

Avaliação do preparo de canais radiculares achatados a partir da diafanização

Objective: To evaluate, by diaphanization, the cleaning ability three different instruments on walls of flattened root canals. Methods: Thirty lower incisors, which had their root canals filled with India ink after coronal access and determination of the working length, were selected. The samples were randomly divided into three groups, of 10 teeth each, according to the instrument used during preparation: Group 1– hand files instrumentation; Group 2– instrumentation with ProTaper Universal rotary files; Group 3 – instrumentation with iRace rotary files. After instrumentation, the teeth were diaphanized and evaluated for cleaning ability, by analyzing the amount of dentin walls in which Indian ink was not removed. Results: When performing the Kruskal-Wallis test (p>0.05) there were not significant statistical differences between groups, as well as for the arithmetic average of the scores at cervical, middle and apical thirds. Conclusion: None of the instruments used for root canal preparation of flattened root canals was able to perform a complete cleaning of the dentin walls.

Influence of Cervical and Apical Enlargement Associated with the WaveOne System on the Transportation and Centralization of Endodontic Preparations

IntroductionThe aim of this study was to evaluate through computed microtomography the transportation and centralization of root canals instrumented using the WaveOne system (Dentsply Maillefer, Ballaigues, Switzerland) associated or unassociated with previous apical and cervical enlargements. MethodsThirty-six mandibular molars were selected with independent mesial roots and curvatures and randomized into the following groups: PathFile (Dentsply Maillefer) before WaveOne Primary (the PFWO group), ProTaper Universal SX (Dentsply Maillefer) before WaveOne Primary (the SXWO group), and WaveOne Primary (the WO group). Computed microtomographic imaging was performed pre- and postpreparation to obtain measurements of mesial and distal dentin walls and calculations of root canal transportation (%) and centralization. One-way analysis of variance was performed to compare the different groups, repeated measures analysis of variance for comparison of the root thirds in each group, and the Student t test for comparisons between the mesiobuccal and mesiolingual canals. ResultsTransportation of the cervical and middle thirds to the danger zone was observed in both roots, whereas the apical thirds were transported to the outer face of the curvature. In the PFWO and SXWO groups, less transportation was observed in the middle thirds of the mesiobuccal canals compared with the WO group (P < .05). Centralization remained almost unchanged in the SXWO group (P < .05). ConclusionsIn each group, transportation toward the danger zone was mostly observed in the cervical thirds of the mesiobuccal canals. Cervical or apical enlargement resulted in reduced transportation and improved centralization of the middle thirds compared with the exclusive use of the WaveOne system.

“Comparative evaluation of dentinal penetration of three different endodontic sealers with and without smear layer removal” - Scanning electron microscopic study

Aim and Objectives: The aim of this study was to test the dentinal tubule penetration of mineral trioxide aggregate (MTA) Fillapex (Angelus, Londria, PR, Brazil), GuttaFlow® 2 sealer (Coltene/Whaledent) with standard sealer AH Plus (Dentsply Detrey, Konstanz, Germany) in instrumented root canals obturated by using cold lateral compaction techniques in either the presence or absence of the smear layer. Materials and Methods: Sixty extracted human mandibular premolars with a single root canal were used for this study. All teeth were prepared using F2 Pro Taper nickel–titanium rotary system. Teeth were randomly divided into three groups of 20 teeth each. GuttaFlow 2, MTA Fillapex and AH Plus were used as sealers in Group I, Group II, and Group III, respectively. Groups were divided into two subgroups in which either the smear layer was removed or retained. Removal of smear layer was achieved by continuous irrigation with 5.25% sodium hypochlorite and 2 ml of 17% ethylenediaminetetraacetic acid. The canals were dried and obturated using respective sealers by cold lateral compaction techniques. After storage at 37°C and 100% humidity for 14 days, the roots were then split into two halves using chisel and mallet. On each section, sealer penetration in the dentinal tubules at cervical, middle, and apical levels was examined by using scanning electron microscope. Results: Sealer penetration into the dentinal tubules was noticed in all groups. AH plus showed deeper penetration, followed by MTA Fillapex and GuttaFlow® 2. The penetration depth of the sealers at the cervical and middle third of root was significantly more than those at apical third. Conclusions: Within the parameters of the present study it was concluded, with the removal of smear layer AH plus sealer showed deeper penetration into the dentinal tubules at cervical and middle third of root compared with apical third.

A finite element study to determine the occurrence of abfraction and displacement due to various occlusal forces and with different alveolar bone height.

Background:Noncarious cervical lesions (NCCLs) are rarely described in the periodontal literature, perhaps because no direct link between NCCLs and periodontal lesions has been demonstrated.Aim:The aim of this study is to determine the stress and displacement produced in the tooth at different bone levels under different occlusal load using finite element model (FEM) study.Materials and Methods:Four FEMs of maxillary incisor were designed consisting of the tooth, pulp, periodontal ligament, and alveolar bone at the various level of bone height (25%, 50%, and 75%). Different occlusal load (5 kg, 15 kg, 24 kg, and 29 kg) at an angle of 50° to the long axis of the tooth was applied on the palatal surface at the level of middle third of the crown. All the models were assumed to be isotropic, linear and elastic, and the analysis was performed on a Pentium IV processor computer using the ANSYS software.Results:The maximum stress in the tooth was seen in the cervical region and to a greater extent at the apex for all models. The maximum tooth displacement for all the occlusal loads applied in this study was at the incisal edge with the minimum tooth displacement at the cervical third of the root which shifted apically with the reduction of alveolar bone support.Conclusion:The cumulative effect of increased stress and displacement at the cervical region of the tooth would result in abfraction as the age advances along with other wasting diseases.

Effect of Citric Acid and Ethylenediaminetetraacetic Acid on the Surface Morphology of Young and Old Root Dentin.

Introduction:The aim of this in vitro study was to evaluate the effect of 10% citric acid and 17% ethylenediaminetetraacetic acid (EDTA) irrigating solutions on the surface morphology of young and old root dentin by determining the number and diameter of dentinal tubules using scanning electron microscopy (SEM). Methods and Materials:Fifty healthy human teeth collected from young (≤30 years) and old (≥60 years) individuals (n=25) were first prepared with a Largo bur #2 to produce smear layer on the root canal surface. Subsequently, the crowns and the root middle and apical thirds were sectioned and removed, and the cervical thirds were sectioned vertically in the buccal-lingual direction into two equal halves. The obtained samples were then immersed in 2.5% sodium hypochlorite for 30 min and randomly separated into two treatment groups for each age group. In each age group, ten samples were selected as controls and did not receive any type of treatment. The rest of the specimens were then rinsed, dried and treated for 4 min with 10% citric acid or 17% EDTA. The samples were then assessed with SEM regarding the number and diameter of dentinal tubules. All data were assessed using Student’s t-test. The level of significance was set at 0.05. Results:Regardless of the type of treatment, no significant differences were observed in the number of open tubules between the young and old root dentin (P>0.05). Nonetheless, the diameter of the tubules in the old root dentin was larger when 17% EDTA was used (P<0.05). Both, young and old root dentin did not differ with the 10% citric acid treatment (P>0.05). Conclusion:The results showed that 17% EDTA treatment induced a significant demineralization in old root dentin.

Management of Horizontal Root Fracture in the Middle Third via Intraradicular Splinting Using a Fiber Post.

Radicular fractures in permanent teeth are uncommon injuries and account for only 0.5–7% of dental traumas. These fractures commonly result from a horizontal impact and are transverse to oblique in direction. Their incidence is more in the middle third of the root than at the apical and cervical thirds. This paper describes a case of complicated crown fracture of maxillary incisors along with horizontal root fracture at the middle third of maxillary right central and lateral incisor. The fractured root fragments of the upper right central and lateral incisor were united with the help of a glass fiber post after receiving an endodontic treatment. The other two incisors were treated endodontically followed by post endodontic restorations. Eventually the four incisors were restored with porcelain fused to metal crowns. A one-year follow-up revealed a well stabilized assembly of the root fragments and the post.

Influence of operating microscope in the sealing of cervical perforations.

Context:Accidental root canal perforations are among the main complications of endodontic treatment.Aim:This study evaluated the influence of operating microscope (OM) in the marginal adaptation of mineral trioxide aggregate (MTA) (Angelus®) and glass ionomer (Vitremer) inserted into cervical perforations.Materials and Methods:Perforations were made in the cervical third of the buccal wall of the root canal in mandibular incisors. Next, the teeth were divided into four groups (N = 10): MG — MTA without OM; VG — Vitremer without OM; MOMG — MTA with OM; VOMG — Vitremer with OM. The perforations were sealed according to the group and the teeth were prepared for analysis by confocal laser scanning microscope. Images of perforation region (1,024×) were made and the gap presented by the materials was measured using the Image J program. LEXT OLS4100 three dimensional (3D) measuring laser microscope measured the volumetric misfit. Data of gap were analyzed by Kruskal-Wallis and Dunn's tests. Analysis of variance (ANOVA) and Tukey's tests compared the volumetric misfits.Results:The results showed lower volume and gap in the interface dentin/material in VOMG compared to the other groups (P < 0.05).Conclusion:The use of OM improved the quality of cervical perforations sealed with Vitremer, being indicated in clinical situations of iatrogenic cervical perforations.

A scanning electron microscope evaluation of smear layer removal from root canals prepared by manual or rotary instrumentation using three different irrigating systems: An in vitro study

Introduction: Smear layer removal after root canal instrumentation requires the use of irrigating solutions, either alone or in combination. The mechanical debridement efficacy of an irrigation delivery/agitation system is dependent on its ability to deliver the irrigant to the apical and noninstrumented regions of the canal space and to create a strong enough current to carry the debris away from the canal walls. Materials and Methods: Ninety extracted single-rooted anterior teeth were included in the study and divided into two groups of 45 each. Biomechanical preparation was done with hand files in Group A and with rotary files in Group B. Three subgroups were further made from each group, wherein Max-I-Probe, Endosonic files, and EndoActivator irrigation systems were used in subgroups I, II, and III, respectively. After irrigation with 10% citric acid, specimens were split and the root surfaces were evaluated under scanning electron microscope at cervical, middle, and apical levels. Results: The removal of smear layer was more complete in coronal and middle thirds than in the apical third. No significant difference was found on the removal of smear layer in manually or rotary instrumented groups. When mean scores for all the groups were obtained, Max-I-Probe hand file (Group IA) was found to be most effective in cleaning smear layer in cervical third of root canals, whereas Endosonic rotary showed the best result in both middle and apical third. Conclusion: EndoActivator system did not enhance the removal of smear layer as compared with Endosonic system and the conventional Max-I-Probe irrigation with NaOCl and 10% citric acid. removal of smear layer was more complete in coronal and middle thirds than in the apical third.

Comparison of Tooth Discoloration Induced by Calcium-Enriched Mixture and Mineral Trioxide Aggregate.

Introduction:The aim of this in vitro study was to evaluate the tooth discoloration induced by calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA). Methods and Materials:Forty five endodontically treated human maxillary central incisors were selected and divided into three groups (n=15) after removing the coronal 3 mm of the obturating materials. In the MTA group, white MTA plug was placed in pulp chamber and coronal zone of the root canal. In CEM cement group, CEM plug was placed in the tooth in the same manner. In both groups, a wet cotton pellet was placed in the access cavity and the teeth were temporarily sealed. After 24 h the teeth were restored with resin composite. In the negative control group the teeth were also restored with resin composite. The color change in the cervical third of teeth was measured with a colorimeter and was repeated 3 times for each specimen. The teeth were kept in artificial saliva for 6 months. After this period, the color change was measured again. Data were collected by Commission International de I'Eclairage's L*a*b color values, and corresponding ΔE values were calculated. The results were analyzed using the one-way ANOVA and post-hoc Tukey’s test with the significance level defined as 0.05. Results:There was no significant differences between CEM group and control group in mean discoloration. The mean tooth discoloration in MTA group was significantly greater than CEM and control groups (P<0.05). Conclusion:According to the result of the present study CEM cement did not induce tooth discoloration after six months. Therefore it can be used in vital pulp therapy of esthetically sensitive teeth.

The effect of three different antioxidants on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin: An in vitro study.

Objective:The effect of 10% ascorbic acid, 10% tannic acid, and 10% gallic acid on the dentinal tubular penetration of Resilon and Real Seal SE on sodium hypochlorite-treated root canal dentin was evaluated.Materials and Methods:Fifty human premolars were decoronated to attain 14-mm root length and divided into five groups of 10 teeth each. Biomechanical preparation was done with rotary instruments. Group I specimens were irrigated with saline and 17% ethylenediaminetetraacetic acid (EDTA). Specimens from groups II, III, IV, and V were irrigated with 5.25% sodium hypochlorite and 17% EDTA. Specimens from groups III, IV, and V underwent additional irrigation with antioxidants–10% ascorbic acid, 10% tannic acid, and 10% gallic acid, respectively. Following obturation with Resilon and Real Seal SE, scanning electron microscope (SEM) analysis was done to note the maximum dentinal tubular penetration at the cervical, middle, and apical thirds of each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA), Post hoc and Dunnett's test.Results:Maximum dentinal tubular penetration of Resilon and Real Seal SE was obtained following irrigation with 10% gallic acid.Conclusion:10% gallic acid was superior among the antioxidant irrigants that enabled the increased dentinal tubular penetration of Resilon and Real Seal SE.

An in vitro Comparative Evaluation of Three Remineralizing Agents using Confocal Microscopy.

The caries process has been thought to be irreversible, resulting in the permanent loss of tooth substance and eventually the development of a cavity. Recent approaches focused on application of remineralizing agents to incipient carious lesions, aim at controlling demineralization and promoting remineralization. Remineralizing agents create a supersaturated environment around the lesion; thus, preventing mineral loss and forces calcium and phosphate ions in the vacant areas. To compare and evaluate the remineralization potential of Fluoride Varnish, CPP-ACP Paste (Casein Phosphopeptide-Amorphous Calcium Phosphate) and fTCP Paste (functionalized Tricalcium Phosphate) using confocal microscope. Two windows of 3X3mm were created on the labial cervical and incisal thirds in 60 permanent maxillary central incisors. The teeth were demineralized to create artificial caries and divided into three groups of 20 each. Group I specimens were coated with Fluoride Varnish once whereas those in CPP-ACP paste group and fTCP group were brushed for 2 minutes, twice daily for 20 and 40 days. The specimens were stored in artificial saliva during the study period and were later sectioned and observed under confocal microscope. Data obtained was statistically analyzed using Fischer's exact test, ANOVA and post-hoc Bonferroni's test. Fluoride Varnish, CPP-ACP Paste and fTCP Paste showed remineralization of artificial carious lesions at both the time intervals. Fluoride varnish showed the highest remineralization followed by CPP-ACP Paste and fTCP Paste. A statistically significant increase in remineralization potential of CPP-ACP Paste and fTCP Paste was observed at the end of 40 days as compared to 20 days. Fluoride varnish showed the greatest remineralization potential of artificial carious lesions followed by CPP-ACP Paste and fTCP Paste respectively.

Influence of the Cement Film Thickness on the Push-Out Bond Strength of Glass Fiber Posts Cemented in Human Root Canals.

The present study evaluated the influence of the cement film thickness on the push-out bond strength of glass fiber posts in the cervical, medium, and apical thirds of root canal spaces. Thirty roots were randomly divided into three groups, according to the fiber post system's drills: (G1) #2; (G2) #3; (G3) #4. The posts were cemented using a self-adhesive cement, and a small amount of powdered Rhodamine B was used as a stain. Images of both sides of each slice were obtained before and after the push-out test. To determine the cement thickness, a macro routine was developed using the software KS 400. The data were analyzed statistically using Kruskal-Wallis and Dunn's test. G2 (14.62 ± 5.15 MPa) showed statistically higher bond strength values than G1 (10.04 ± 5.13 MPa) and G3 (7.68 ± 6.14 MPa). All groups presented higher bond strength values in the apical third. The bur diameter significantly influenced the results of the shear bond strength for the push-out test. The slight increase in the cement thickness allowed an increase in the values of shear bond strength when compared to very thin or very thick cement films.

Examination of natural tooth color distribution using visual and instrumental shade selection methods

Aim: Although visual color determination is the most frequently applied method in dentistry, instrumental color analysis offers advantages like objectivity, measurability and rapidity. The aim of this study was to evaluate the natural teeth color in teeth without any restoration visually, and by using a computerized shade measuring and analyzing system in the population. Materials and Methods: 202 patients were inspected. Before instrumental shade matching visual matching was done by the inspector with Vitapan 3D Master Shade Guide in the day light. Images were taken with computerized shade measuring and analyzing system from patients ' natural right or left maxillary incisors and canines without any restoration. Then these images were evaluated by the original software of its own. Results: Value differences between visual and instrumental shade matching were statistically significant. Darker value levels were obtained with instrumental measurement. The distribution of hue was more reddish in instrumental examination than visual examination. Significant difference was found at cervical and middle third of the tooth in both visual and instrumental determination of chroma. Chroma of the tooth was higher at these two regions in visual assessment. Conclusions: Teeth colors were distributed more uniform in visual shade matching compared to instrumental matching. However, some teeth shades were more common in instrumental matching. Value scores were found higher with instrumental shade matching. Individual selection of shades for each tooth and different regions of a tooth instead of a single color is considered to be a factor to increase the success of the restoration.

Push-out bond strength of different translucent fiber posts cemented with self-adhesive resin cement.

Purpose:Evaluate the bond strength of different translucent fiber posts in the cervical, middle, and apical root thirds cemented with self-adhesive resin cement.Materials and Methods:Sixty single-rooted teeth were randomly divided into five groups according to the fiber post used: Reforpost (opaque [control]), exacto, white post, radix, and Macro-Lock Illusion X-RO. The roots were subjected to chemomechanical preparation and cemented with self-adhesive resin cement. The teeth were sectioned into slices of the different root thirds and tested for bond strength (push-out). Two-way analysis of variance and Bonferroni test were used to verify statistical differences between groups (P < 0.05).Results:No significant difference between the root thirds was detected (P > 0.05). However, the performance of the posts demonstrated a significant difference (P < 0.05). RDX had a lower performance in the apical third (P < 0.05). The other fiber posts had the same performance irrespective of the root third evaluated. The predominant failure pattern was adhesive between resin cement and root dentin.Conclusion:In general, the different translucent fiber posts showed the same performance. Yet, translucent fiber posts did not show superior bond strength compared with the opaque fiber post in any of the root thirds evaluated.

Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files.

AimTo evaluate the incidence of apical crack initiation during canal preparation with stainless steel K-files and hand protaper files (in vitro study).Materials and methodsSixty extracted mandibular premo-lar teeth are randomly selected and embedded in an acrylic tube filled with autopolymerizing resin. A baseline image of the apical surface of each specimen was recorded under a digital microscope (80×). The cervical and middle thirds of all samples were flared with #2 and #1 Gates-Glidden (GG) drills, and a second image was recorded. The teeth were randomly divided into four groups of 15 teeth each according to the file type (hand K-file and hand-protaper) and working length (WL) (instrumented at WL and 1 mm less than WL). Final image after dye penetration and photomicrograph of the apical root surface were digitally recorded.ResultsMaximum numbers of cracks were observed with hand protaper files compared with hand K-file at the WL and 1 mm short of WL. Chi-square testing revealed a highly significant effect of WL on crack formation at WL and 1 mm short of WL (p = 0.000).ConclusionMinimum numbers of cracks at WL and 1 mm short of WL were observed with hand K-file and maximum with hand protaper files.How to cite this articleSoni D, Raisingani D, Mathur R, Madan N, Visnoi S. Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files. Int J Clin Pediatr Dent 2016;9(4):303-307.

Analysis of the effect of ultrasonic agitation on the cleaning of root canals using different periods during the final irrigation

The ultrasonic agitation was introduced as an adjuvant to conventional chemo-mechanical debridement during endodontic treatment to overcome the persistence of biofilms. Objective: To verify the cleaning of root canals irrigated with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), with or without an ultrasonic agitation, using different time periods and images obtained by scanning electron microscope (SEM). Material and methods: Forty mandibular incisors were cleaned, shaped and randomly divided into five groups according to the final irrigation protocol: SH10 group (ultrasonic agitation with NaOCl for 10 s), SH30 group (ultrasonic agitation with NaOCl for 30 s), SHE30 group (ultrasonic agitation with NaOCl and EDTA for 10 s), SHE90 group (ultrasonic agitation with NaOCl and EDTA for 30 s), and control group (NaOCl and EDTA without ultrasonic agitation). The teeth were prepared and analyzed by SEM at ×2000. The Kruskal–Wallis test was used with a 5% level of significance. Results: For the cervical and medial thirds, there was no statistically significant difference in cleaning among the protocols used (p &gt; 0.05). For the cleaning of the apical third, SHE90 group demonstrated a significant difference (p &lt; 0.05), as compared to the control and SH10 groups. Conclusion: For the final irrigation, an ultrasonic agitation with NaOCl and EDTA for 30 s allowed a better cleaning of the debris in the apical third of the root canal.

Effect of Resin Cement Porosity on Retention of Glass-Fiber Posts to Root Dentin: An Experimental and Finite Element Analysis.

The aim of this study was to evaluate the effect of porosity of self-adhesive resin on the stress distribution, post retention and failure mode of fiber post cemented to human root dentin. Ten human central upper incisors with circular root canal were selected. They were sectioned with 15 mm and were endodontically filled. The roots were scanned using micro-CT after post space preparation for root filling remaining evaluation. Fiber posts were cemented using self-adhesive resin cement (Rely X U200, 3M-ESPE). Two 1-mm-thick slices from the cervical, medium and apical thirds were scanned for resin cement bubbles volume measurements and submitted to a push-out test (PBS). Three operators using stereomicroscopy and confocal laser microscopy classified the failure mode. Stress distributions during the push-out test were analyzed using 3D finite element analysis. PBS values (MPa) were submitted to one-way ANOVA and Tukey's post hoc tests and the failure modes using the Kappa coefficient to assess inter-operator agreement. Chi-square test was used to determine significant differences between the methods ( = 0.05). Push-out bond strength was significantly affected by the bubbles presence in all root depth (p<0.05). The stress concentration was higher when the bubbles were present. Adhesive dentin/resin cement interface failure was the most frequent type of failure. Confocal microscopy was better than stereomicroscopy for failure analysis. Bubbles generated during resin cement insertion into the root canal negatively affect the stress distribution and the bond strength. The use of confocal microscopy is recommended for failure analysis.

The impact of periodontal disease on cementochronology age estimation

Estimating an individual’s age at death is essential for post-mortem identification, paleopathology and paleodemography. With substantial development over the past 10 years in cementochronology analyses, some concerns have arisen that oral pathological conditions may artificially reduce or increase cementum apposition.The objective of this study was to observed the impact of periodontal disease on acellular cementum and on the reliability of cementochronology to test its accuracy for estimating individual age at death. The study included 41 teeth presenting different degrees of bone destruction, extracted from 18 individuals affected by untreated periodontal disease.The results demonstrated that the degree of alveolysis had only limited effects on the counting of cementum annulations in the middle (rp=0.92, p<0.01 between estimated and civil age) and the cervical (rp=0.85, p<0.01) thirds of the root, whereas in the apical third, the increments were affected considerably. This cementum reactive process compensates for bone destruction and loss of the attachment apparatus. These data suggest that cementum could continue to grow at a slower rate despite bone destruction due to periodontal disease. Cementochronology can thus be applied to teeth with a damaged periodontium by sectioning the middle third of the root.

ANÁLISE DA CAPACIDADE DE LIMPEZA DE TRÊS TÉCNICAS DE INSTRUMENTAÇÃO EM CANAIS RADICULARES ACHATADOS: DIAPHANIZATION STUDY

O objetivo desse estudo foi avaliar utilizando a diafanização, a capacidade de limpeza das paredes de canais radiculares achatados preparados com três diferentes instrumentos. Foram selecionados 30 incisivos inferiores que após abertura coronária e odontometria tiveram os canais preenchidos com tinta nanquim, em seguida foram divididos aleatoriamente em três grupos de 10 dentes cada, de acordo com o instrumento utilizado no preparo: Grupo 1 – instrumentação com limas manuais; Grupo 2 – instrumentação com limas rotatórias ProTaper Universal; Grupo 3 – instrumentação com limas rotatórias iRace. Após a instrumenta- ção, os dentes foram diafanizados e avaliados quanto a capacidade de limpeza, analisando-se a quantidade de paredes dentinárias em que a tinta nanquim não foi removida. Ao se realizar o teste de Kruskal Wallis (p&gt;0,05) não foram observadas diferenças estatisticamente significantes entre os grupos, quanto a média aritmética dos escores nos terços cervical, médio e apical. Nenhum dos instrumentos utilizados no preparo biomecânico de canais radiculares achatados foi capaz de realizar uma completa limpeza das paredes dentinárias.

ANÁLISE DA CAPACIDADE DE LIMPEZA DE TRÊS TÉCNICAS DE INSTRUMENTAÇÃO EM CANAIS RADICULARES ACHATADOS: DIAPHANIZATION STUDY

The purpose of this study was to evaluate by diaphanization the cleaning ability of walls of flattened root canals prepared with three different instruments. Thirty lower incisors, which had their root canals filled with India ink after coronal access and determination of the work length, were selected. The samples were randomly divided into three groups of 10 teeth each, according to the instrument used in the preparation: Group 1– hand files instrumentation; Group 2– instrumentation with ProTaper Universal rotary files; Group 3 – instrumentation with iRace rotary files. After instrumentation, the teeth were diaphanized and evaluated by cleaning ability, analyzing the amount of dentin walls in which India ink was not removed. When performing the Kruskal-Wallis test (p&gt;0.05) there were not statistical significant differences between the groups, as the arithmetic average of the scores at cervical, middle and apical thirds. None of the instruments used in root canal preparation of flattened root canals was able to perform a complete cleaning of the dentin walls.