Efficacy of an iodoform-based filling material for pulpectomy of primary teeth: A 24-month non-inferiority randomized clinical trial.

AIM: The aim of this non-inferiority randomized clinical trial was to compare the efficacy of an iodoform-based paste (Guedes-Pinto -(GP)) as a filling material in pulpectomies of primary teeth, and a standard material composed by calcium hydroxide and iodoform (CaOH/Iodof paste; Vitapex® ). DESIGN: A total of 104 teeth from 61 children (3-8 years old) were randomly allocated to two groups according to filling materials. Children were followed up for 24 months. The primary endpoint was the treatment success rate evaluated through clinical and radiographic examinations at follow-up, and the secondary outcome was the analysis of the canal filling quality. Differences in the proportion of treatment success was calculated based on 95% confidence intervals (95% CI) and with the Miettinen and Nurminen method in the intention-to-treat population, considering a -20% of the non-inferiority limit. RESULTS: From 104 randomized teeth, 102 were followed up after 24 months (attrition rate of 1.9%). The success rate of teeth treated with the GP paste was 86.8% (95% CI: 69.9-94.9) and 78.4% (95% CI: 61.8-89.1) with the CaOH/Iodof paste. Consequently, a non-inferiority of the GP paste was observed when compared to the CaOH/Iodof paste (P < .001). CONCLUSION: The GP paste has a non-inferior success rate than the CaOH/Iodof paste used as filling material for pulpectomy in primary teeth.

Laser for bone healing after oral surgery: systematic review.

The purpose of this study is to perform a systematic review on the use of lasers in oral surgery for bone healing. Selection of articles was carried out by two evaluators in Pubmed and Web of Science databases for published articles and OpenGray for gray literature. Search strategy was developed based on the PICO Question "Does the use of lasers after oral surgery improve bone healing?". Eligibility criteria were: being on laser; evaluate bone healing; involve oral surgery; do not be about implant, periodontics, orthodontics, osteonecrosis or radiotherapy, nor revisions, clinical cases, etc. Data were collected from each article in a structured spreadsheet and a descriptive analysis was performed. Risk assessment of bias of the articles was carried out through the tool elaborated by the Cochrane collaboration. A total of 827 potentially relevant references were identified. No articles were found in OpenGray. Eleven articles met the eligibility criteria and were included in the systematic review. Most of studies were in vivo and in jaw, being conducted with low-power lasers which were applied immediately after the surgical procedure of extraction. Neoformation and bone density were the outcomes of choice and there was a tendency of increase in bone density, neoformation, regeneration, mineralization, or bone condensation when laser was applied. Regarding the bias risk assessment, studies were not clear in reporting most of the parameters. Low-power laser therapy seems to reduce time of bone healing in oral surgery, although there are no defined protocols and the level of evidence is still considered weak.

Use of artificial primary teeth for endodontic laboratory research: experiments related to canal length determination.

BACKGROUND: Due to the scarcity of exfoliated/extracted human primary teeth with complete roots, artificial teeth were developed as an alternative to be used for educational and laboratory research purposes. This study aimed to assess the feasibility of using artificial primary teeth for conducting laboratory research through an experiment related to canal length determination, comparing artificial teeth with natural teeth. METHODS: Thirty anterior and 21 posterior artificial teeth, and the same number of natural primary teeth were selected. After preparing the access cavity, the root canal length was determined by two examiners twice using three different methods: radiography and two electronic apex locators. Then, the actual root canal length was measured by inserting a K-file up to the apical foramen (reference standard). Accuracy was calculated using Bland-Altman analysis and intraclass correlation coefficient (ICC). The inter- and intra-examiner reproducibility was also calculated using the ICC. RESULTS: The methods using the electronic apex locators showed better accuracy in both artificial and natural teeth. Trends observed with artificial primary teeth were similar to those observed with natural teeth, except for the results in artificial anterior teeth. CONCLUSIONS: The model of artificial teeth might be a good alternative for educational purposes; however, improvements are necessary to employ these teeth for research purposes when considering experiments for canal length determination.

Pulp Calcification in Traumatized Primary Teeth - Classification, Clinical And Radiographic Aspects.

OBJECTIVE: The aim of this study was to standardize the nomenclature of pulp alteration to pulp calcification (PC) and to classify it according to type, quantity and location, as well as relate it to clinical and radiographic features. STUDY DESIGN: The dental records of 946 patients from the Research and Clinical Center for Dental Trauma in Primary Teeth were studied. Two hundred and fifty PC-traumatized upper deciduous incisors were detected. RESULTS: According to radiographic analysis of the records, 62.5% showed diffuse calcification, 36.3% tube-like calcification, and 1.2% concentric calcification. According to the extension of pulp calcification, the records showed: 80% partial calcification, 17.2% total coronal calcification and partial radicular calcification, and 2.8 % total coronal and radicular calcification. As for location, only 2.4% were on the coronal pulp, 5.2% on the radicular pulp and 92.4% on both radicular and coronal pulp. Regarding coronal discoloration, 54% were yellow and 2% gray. In relation to periradicular changes, 10% showed widened periodontal ligament space, 3.1% internal resorption, 10% external resorption, 10.4% periapical bone rarefaction. CONCLUSIONS: Since PC is a general term, it is important to classify it and correlate it to clinical and radiographic changes, in order to establish the correct diagnosis, treatment and prognosis of each case.

Do the ball-ended probe cause less damage than sharp explorers?-An ultrastructural analysis.

BACKGROUND: No evidence about damage caused by ball-ended probes on tooth is available. No study compared probing defects caused by ball-ended probes with sharp explorers during tactile examinations of primary teeth. This exploratory study aimed to compare ultrastructural defects caused by ball-ended probes with sharp explorers during tactile examinations of primary teeth. METHODS: Forty-nine primary extracted teeth were tactile examined as performed for caries activity assessment. Surfaces were randomly divided into groups based on probe type (ball-ended probe or sharp explorer). Two examiners probed different surfaces using the sharp explorer and the ball-ended probe. The order for examination was randomly determined. Images were captured using environmental scanning electron microscopy (ESEM) before and after probing. Two external examiners evaluated independently the ESEM images and scored them as: 0) no damage, 1) slight marks, 2) distinct marks, 3) marks with discontinuity, 4) enamel break-offs. Multilevel Poisson regression models were used to analyze associations between probing ultrastructural damage and surface type, baseline condition and probe type. Prevalence ratios (PR) were calculated with 95 % confidence interval (CI). RESULTS: The most common defects observed on the dental surfaces were probing marks without discontinuity (scores 1 and 2). Ball-ended probes caused significantly less severe damage than sharp explorers (PR: 0.28; CI: 0.11-0.76, p = 0.01). CONCLUSION: Ball-ended probes cause less damage than sharp explorers when probing gently dental surfaces of primary teeth.

Effect of chemical and Er:YAG laser treatment on bond strength of root canal resin-based sealers.

Different treatments of dentin walls, as laser irradiation, prior to obturation can influence the adhesion ability of endodontic sealers. Therefore, the objective of this study was to compare in vitro the shear bond strength of four resin-based sealers to dentin treated with citric acid solution or erbium: yttrium, aluminum, garnet (Er:YAG) irradiation. A total of 240 slices with 1.6 mm of thickness were cut using middle third of 84 teeth. Each slice was widened using a #45 taper.06 rotary K3 instrument. The sample was divided into groups according to dentin pretreatment (15 % citric acid or Er:YAG laser) and sealer used (AH Plus, Acroseal, EndoREZ, or RealSeal). Shear bond strength was measured using a universal materials testing machine. As results, significant differences were found when comparing sealers between all groups (p < 0.05) by Kruskal-Wallis test, regardless of the pretreatment used. Comparing pretreatments, 15 % citric acid solution had better outcomes than Er:YAG laser, with significant differences in all groups, except for Acroseal groups (p < 0.05). It was concluded that RealSeal and 15 % citric acid solution achieved the best results regarding the sealer and pretreatment used, respectively.

Bactericidal effects of two parameters of Er:YAG laser intracanal irradiation: ex-vivo study.

The success of endodontic treatment depends on the complete elimination of microorganisms from the root canal system, thus the search for new procedures to eliminate them is justified. The aim of this study was to assess bacterial reduction after intracanal irradiation with the Er:YAG laser. The canals of 70 extracted human maxillary canines were prepared up to file #40 using 1% NaOCl, irrigated with 17% EDTA, and then washed with physiological solution activated by ultrasound. The roots were sterilized by autoclaving, inoculated with 10 µl of a suspension containing 1.5 × 10(8) CFU/ml of Enterococcus faecalis ATCC 29212 and incubated at 37°C for 72 h. The canals were irradiated with the Er:YAG laser using two energy settings: 60 mJ and 15 Hz, and 100 mJ and 10 Hz. The remaining bacteria were counted immediately and 48 h after laser irradiation. The results showed a high bacterial reduction at both time points. With 60 mJ and 15 Hz there was an immediate reduction of 99.73% and the reduction was 77.02% after 48 h, and with 100 mJ and 10 Hz there was an immediate reduction of 99.95% and the reduction was 84.52% after 48 h. Although the best results were observed with 100 mJ of energy, the difference between the two settings was not statistically significant. The count performed 48 h after irradiation showed that E. faecalis were able to survive, and can grow even from small numbers.

Optical magnification has no benefits on the detection of occlusal caries lesions in permanent molars using different visual scoring systems: An in vitro study.

BACKGROUND: Some studies have addressed the influence of optical magnification on the detection of caries lesions using a visual scoring system. However, there is a lack of research related to the use of the CAST and ADA-CCS visual scoring systems. In addition, the reliability and accuracy of ADA-CCS index in permanent teeth were not studied yet. So, the aim of this study was to evaluate, in vitro, the influence of different levels of optical magnification on the detection of occlusal caries lesions in permanent molars using three visual scoring systems. MATERIAL AND METHODS: One occlusal site per tooth was analyzed in 120 extracted permanent molars. Two trained examiners inspected the teeth using ICDAS (International Caries Detection and Assessment System), CAST (Caries Assessment Spectrum and Treatment), and ADA-CCS (American Dental Association-Caries Classification System) visual criteria, twice with each scoring system, with a one-week interval between examinations. The study was conducted in three phases: (A) without optical magnification, (B) using a binocular lens (3.5× magnification), and (C) using an operating microscope (16× magnification). Then, the teeth were sectioned longitudinally through the center of the selected site and the section with the more severe lesion was histological evaluated considering the D1 (lesions in enamel and dentin) and D3 (dentin lesions) thresholds. RESULTS: Kappa values for intra- and inter-examiner reproducibility were good to excellent for all systems. At the D1 threshold, sensitivity, accuracy, and area under the ROC curve were high for ICDAS and CAST in all phases. However, this was not the case for the ADA-CCS in phase C (<0.05). At the D3 diagnostic threshold, there was no significant difference between the visual scoring systems during the study phases (>0.05). CONCLUSIONS: The magnification does not improve the accuracy of the visual scoring systems in the detection of occlusal caries lesions in permanent molars. Key words:Dental caries, caries detection, permanent teeth, visual examination, magnification.

Physicochemical properties and filling capacity of an experimental iodoform-based paste in primary teeth.

In this study, we evaluated the physicochemical properties (PCP; radiopacity, flow, pH, and solubility) and the quality of root canal filling provided by an experimental industrialized paste (EP), with the same active ingredients as those of the Guedes Pinto paste, compared with the Vitapex® paste. PCP were analyzed according to the ANSI/ADA laboratory testing methods for endodontic filling and sealing materials. To analyze filling capacity, 120 artificial primary teeth (60 maxillary incisors [MIs] and 60 mandibulary molars [MMs]) were endodontically treated. The teeth were divided into eight groups based on the dental group (MIs or MMs), filling material (Vitapex® or EP), and insertion method (syringe or lentulo). The Image J® software was used to analyze the initial an final digital radiographies of each tooth, measuring and comparing root canal and void areas. The percentage of filling failure areas was obtained. Data were submitted to ANOVA and Tukey test of mean comparison. Regarding PCP, both pastes presented results according the ANSI/ADA standards. Flow capacity: Vitapex: 19.6 mm, EP: 25 mm (p < 0.01); radiopacity: Vitapex: 4.47 mmAl, EP: 6.06 mmAl (p < 0.01); pH after 28 days: Vitapex: 7.79, EP: 8.19 (p = 0.12); and solubility after 28 days: Vitapex: 2.68%, EP: 2.89% (p > 0.05). Regarding filling capacity analysis, EP demonstrated 12.5% of failure against 31.5% of Vitapex (p < 0.01). Compared to Vitapex, EP presented statistically significantly better results in flow, radiopacity, pH, and filling capacity. Molars presented more filling failures than incisors. The insertion method using a syringe and a thin tip was significantly better than that using Lentulo spiral carriers.

Morphologic changes and removal of debris on apical dentin surfaces after Nd:YAG laser and diode laser irradiation.

OBJECTIVE: To verify the effects of laser energy on intracanal dentin surfaces, by analyzing the morphologic changes and removal of debris in the apical third of 30 extracted human teeth, prepared and irradiated with the Nd:YAG laser and diode laser. BACKGROUND DATA: Lasers have been widely used in endodontics. The morphologic changes in dentin walls caused by Nd:YAG and diode laser irradiation could improve apical seals and cleanliness. MATERIALS AND METHODS: The protocol used for Nd:YAG laser irradiation was 1.5 W, 100 mJ, and 15 Hz, in pulsed mode, and for diode laser was 2.5 W in continuous mode. Each specimen was irradiated four times at a speed of 2 mm/sec with a 20-sec interval between applications. Five calibrated examiners scored the morphologic changes and debris removal on a 4-point scale. RESULTS: In analyzing the scores, there were no statistically significant differences between the two types of laser for either parameter, according to Kruskal-Wallis testing at p = 0.05. The SEM images showed fusion and resolidification of the dentin surface, with partial removal of debris on the specimens irradiated with the Nd:YAG laser and the diode laser, compared with controls. CONCLUSION: Both lasers promote morphologic changes and debris removal. These alterations of the dentin surface appeared to be more evident in the Nd:YAG laser group, but the diode laser group showed more uniform changes.

Influence of Nd:YAG and diode laser irradiation on apical sealing when associated with AH plus and EndoREZ endodontic cements.

OBJECTIVE: This study aims to evaluate the influence of Nd:YAG and diode laser irradiation on apical sealing when applied before root canal filling done with two different resin-based cements (AH Plus and EndoREZ). BACKGROUND DATA: Lasers have been widely used in endodontics. The morphologic changes in dentin walls caused by Nd:YAG and diode laser irradiation could improve sealing ability of endodontic cements. METHODS: Eighty canine teeth were analyzed by apical leakage of methylene blue dye and by scanning electron microscope (SEM) images of the filling's adaptation to the apical third dentin walls. The laser irradiation parameters for the Nd:YAG laser were 100 mJ, 15 Hz, and 1.5 W, and for the diode laser was 2.5 W (continuous mode). RESULTS: The apical leakage results showed statistically significant differences at the 5% level of significance (Tukey's test, p < 0.05) among the different root canal wall treatments, independently of the root canal filling cement used. The cements also showed significant differences between them on the lased groups. The SEM analysis revealed better filling adaptation for AH Plus and the Nd:YAG laser group, confirming the microleakage results. CONCLUSION: We concluded that the combination of the Nd:YAG laser and AH Plus showed the best results.

Influence of preoperative pain in the success rate of indirect pulp capping: a retrospective study.

BACKGROUND: The association of preoperative pain and indirect pulp treatment in permanent teeth is still unknown. This study aimed to evaluate the influence of preoperative pain in the success rate of indirect pulp capping. METHODS: The sample of this retrospective study was constituted for 133 teeth treated in a Private clinic in Joinvile, Brazil, by one experienced dentist between 2007 and 2012. Data related to clinical and demographic variables that could influence in the success rate of indirect pulp capping were also collected, such patient age and sex, type of teeth and arch. Chi­square test was used to evaluate the association between preoperative pain with postoperative one and success of the treatment. Logistic regression was performed to identify significant clinical and demographical factors associated with the success of the indirect pulp capping. RESULTS: The overall success rate was 100% in the absence of preoperative pain. However, when the preoperative pain was present, the failure rate was 18.3%. Statistical analysis showed significant association between preoperative pain and postoperative one and failure rate of the indirect pulp capping. The other independent variables were not associated with the success rate of the treatment. CONCLUSIONS: The presence of preoperative pain is associated with the decrease of the success rate of indirect pulp capping.

In vitro evaluation of methylene blue removal from root canal after Photodynamic Therapy.

In Endodontics, photosensitizers' such as methylene blue and toluidine blue have been used in Photodynamic Therapy due to their positive results. However, they can stain the dentin from the root canal after Photodynamic Therapy (PDT). The present in vitro study aimed to evaluate different stain removal protocols from root canal after PDT using methylene blue (MB) dye. After mechanical preparation of the root canal of 40 uni-radicular human teeth, PDT was performed using 0,01% MB with parameters of 3min of pre-irradiation and a diode laser irradiation emitting at 660nm, 40mW, 4min, 9.6J. After PDT, different protocols of MB removal were performed: Group 1 - control (0.9% saline solution); Group 2 - sodium hypochlorite (2.5% NaOCl); Group 3-17% ethylenediamine tetraacetic acid (EDTA); Group 4 - passive ultrasonic irrigation (PUI); The color of the dentin of the root canal was measured, before, immediately after the PDT and immediately after the cleaning using a spectrophotometer. The ΔE values found were statistically compared using the ANOVA and Tukey's tests (α=0.05). All the treatments lead to some cleaning of root canal after PDT, however, none of the treatments tested completely removed all staining caused by MB photosensitizer of the root canal. Among the treatments tested, PUI and Hypochlorite 2.5% promoted greater cleaning, with no statistically significant difference between them. In conclusion, within the protocols tested in the present study, no treatments were able to completely remove MB staining of the root canal after PDT.

Low-intensity laser phototherapy enhances the proliferation of dental pulp stem cells under nutritional deficiency.

Dental trauma in immature permanent teeth can damage pulp vascularization, which leads to necrosis and cessation of apexogenesis. Studies on tissue engineering using stem cells from human exfoliated deciduous teeth (SHEDs) have yielded promising results. Laser phototherapy (LPT) is able to influence the proliferation and differentiation of these cells, which could improve tissue engineering. SHEDs (eighth passage) were seeded into 96-well culture plates (103 cells/well) and were grown in culture medium supplemented with 15% defined fetal bovine serum (FBS) for 12 h. After determining the appropriate nutrition deficiency status (5% FBS), the cells were assigned into four groups: 1) G1 - 15% FBS (positive control); 2) G2 - 5% FBS (negative control); 3) G3 - 5% FBS+LPT 3 J/cm2; and 4) G4 - 5% FBS+LPT 5 J/cm2. For the LPT groups, two laser irradiations at 6 h intervals were performed using a continuous wave InGaAlP diode laser (660 nm, with a spot size of 0.028 cm2, 10 mW) in punctual and contact mode. Cell viability was assessed via an MTT reduction assay immediately after the second laser irradiation (0 h) and 24, 48, and 72 h later. We found that G3 and G4 presented a significantly higher cell growth rate when compared with G2 (p < 0.01). Moreover, G4 exhibited a similar cell growth rate as G1 throughout the entire experiment (p > 0.05). These findings indicate that LPT with 5 J/cm2 can enhance the growth of SHEDs during situations of nutritional deficiency. Therefore, LPT could be a valuable adjunct treatment in tissue engineering when using stem cells derived from the dental pulp of primary teeth.

Giant Cell Fibroma in a Two-Year-Old Child.

The giant cell fibroma is a benign nonneoplastic fibrous tumor of the oral mucosa. It occurs in the first three decades of life in the mandibular gingiva, predominantly, showing predilection for females. This article reports a case of giant cell fibroma in a 2-year-old girl, which is an uncommon age for this lesion. The patient was brought for treatment at the Research and Clinical Center of Dental Trauma in Primary Teeth, where practice for the Discipline of Pediatric Dentistry (Faculty of Dentistry, University of São Paulo, Brazil) takes place. During clinical examination, a tissue growth was detected on the lingual gingival mucosa of the lower right primary incisors teeth. The lesion was excised under local anesthesia and submitted to histological examination at the Oral Pathology Department of the Faculty of Dentistry, University of São Paulo, which confirmed the diagnosis of giant cell fibroma. There was no recurrence after 20 months of monitoring. This instance reinforces the importance of oral care from the very first months of life in order to enable doctors to make precocious diagnosis and offer more appropriate treatments for oral diseases, as well as to promote more efficient oral health in the community.

Evaluation of the Root Canal Morphology of Molars by Using Cone-beam Computed Tomography in a Brazilian Population: Part I.

INTRODUCTION: One of the factors influencing the success of endodontic treatment is anatomic knowledge of the root canal system. Because of the difficulties of using conventional radiographic methods to evaluate root canals, cone-beam computed tomography (CBCT) has been very useful for evaluating the morphology of root canals. The purpose of this study was to use CBCT to evaluate differences in the anatomy of the mandibular first molars with respect to the patient's sex and the location of the tooth in a Brazilian population. METHODS: The study included CBCT images from 198 patients (106 women and 92 men), representing a total of 342 teeth. RESULTS: Of the 342 mandibular first molars included in the study, 0.3% had 2 canals, 75.1% had 3 canals, 23.7% had 4 canals, and 0.9% had 5 canals. The ages of the patients ranged from 19 to 81 years old, with an average age of 48.9 years. Women were more likely to have 2 canals on the distal root of the right side than men were (P < .05). CONCLUSIONS: Because the Brazilian population has differences in root canal morphology compared with other populations around the world, further studies are needed to aid endodontic diagnosis and treatment.

Changes in irradiance and energy density in relation to different curing distances.

The present study aimed to assess the influence of curing distance on the loss of irradiance and power density of four curing light devices. The behavior in terms of power density of four different dental curing devices was analyzed (Valo, Elipar 2, Radii-Cal, and Optilux-401) using three different distances of photopolymerization (0 mm, 4 mm, and 8 mm). All devices had their power density measured using a MARC simulator. Ten measurements were made per device at each distance. The total amount of energy delivered and the required curing time to achieve 16 J/cm(2) of energy was also calculated. Data were statistically analyzed with one-way analysis of variance and Tukey's tests (p < 0.05). The curing distance significantly interfered with the loss of power density for all curing light devices, with the farthest distance generating the lowest power density and consequently the longer time to achieve an energy density of 16 J/cm(2) (p < 0.01). Comparison of devices showed that Valo, in extra power mode, showed the best results at all distances, followed by Valo in high power mode, Valo in standard mode, Elipar 2, Radii-Cal, and Optilux-401 halogen lamp (p < 0.01). These findings indicate that all curing lights induced a significant loss of irradiance and total energy when the light was emitted farther from the probe. The Valo device in extra power mode showed the highest power density and the shortest time to achieve an energy density of 16 J/cm(2) at all curing distances.

Penetration of a resin-based filling material into lateral root canals and quality of obturation by different techniques.

The aim of this study was to evaluate the penetration of a resin/polyester polymer-based material (Resilon Real Seal; SybronEndo Corp., Orange, USA) into simulated lateral canals, and the quality of obturations by different techniques. A total of 30 standardized simulated canals were divided into three groups according to the technique of obturation used: MS (McSpadden), SB (SystemB/Obtura II), and LC (Lateral Condensation). To analyze the penetration of the filling material, the simulated canals were digitalized and the images were analyzed using the Leica QWIN Pro v2.3 software. The data of the middle and apical thirds were separately submitted to analysis of variance (ANOVA), followed by the Tukey's test for the comparison of the techniques. Results showed a significant difference (p < 0.05) between groups (LC < SB) in the middle third, and a significant difference (p < 0.05) between groups (LC < SB and MS < SB) in the apical third. To analyze the quality of the obturations, the canals were radiographed and evaluated by three examiners. The Kappa test on interexaminer agreement and the nonparametric Kruskal-Wallis test indicated no significant difference between filling techniques. It was concluded that Resilon achieves greater levels of penetration when associated with thermoplastic obturation techniques.

Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers.

This research analyzed the quality of resin-based sealer adaptation after intracanal laser irradiation. Extracted teeth (n = 168) were root canal treated and divided into four groups, according to dentin surface treatment: no laser; Nd:YAG laser (1.5 W, 100 mJ, 15 Hz); diode laser (2.5 W in CW), and Er:YAG laser (1 W, 100 mJ, 10 Hz). The teeth were divided into four subgroups according to the sealer used: AH Plus, EndoREZ, Epiphany, and EpiphanySE. For testing the sealing after root canal obturation, the penetration of silver nitrate solution was measured, whereas to evaluate the adaptation and penetration of the sealer into the dentin, environmental scanning electron microscopy (ESEM) was used. The ESEM images were analyzed using a four-grade criteria score by three evaluators. The inter-examiner agreement was confirmed by Kappa test and the scores statistically compared by the Kruskal-Wallis' test (p < 0.05). Both adaptation and sealer penetration in root canals were not affected by the laser irradiation. Nd:YAG and diode laser decreased the tracer penetration for AH Plus, whereas EndoREZ and EpiphanySE performances were affected by Nd:YAG irradiation (p < 0.05). It can be concluded that intracanal laser irradiation can be used as an adjunct in endodontic treatment; however, the use of hydrophilic resin sealers should be avoided when root canals were irradiated with Nd:YAG laser.

CT study of the performance of reciprocating and oscillatory motions in flattened root canal areas.

Root canal preparation is an important step in endodontic treatment. The anatomical complexity of the middle third of the root compromises the effective cleaning of this area. Thus, advances have been made in instrumentation techniques and instruments for this purpose. The aim of this study was to evaluate the effects of three different instrumentation systems on the enlargement of the middle thirds of root canals in mandibular incisors. The preparation methods used were the reciprocating systems Reciproc (Group I) and WaveOne (Group II) and the oscillatory system Tilos (Group III). Comparisons were made by three-dimensional image reconstruction with cone-beam computed tomography before and after instrumentation. Changes in area, perimeter, centering ability, and pattern of preparation were analyzed. The results were subjected to ANOVA complemented by the Tukey's test. Changes in area, perimeter, and tendency of transportation showed similar results among groups. The transportation index of the Tilos system was significantly lower than that of the other groups. Qualitative analysis of the preparation pattern showed that the Tilos system had a more uniform preparation, although Reciproc and WaveOne preparations appeared more rounded, incompatible with the original canal anatomy. There was similarity in the systems' performance on flattened areas, although the Tilos system presented a better pattern of root canal preparation and a lower index of transportation.