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.

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.

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

Abstract 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.

Craneosinostosis sindrómica: Características craneodentofaciales, tratamiento ortodón-tico-quirúrgico y factores asociados a tipos de síndrome / Craniossinostose sindrômica: Características craniodentofaciais, tratamento ortodônti-co-cirúrgico e fatores associados aos tipos de síndrome / Syndromic Craniosynostosis: Craniodentofacial features, orthodontic-surgical treatment and factors associated to types of syndrome

Objetivos: Describir las características craneodentofaciales, tratamientos ortodónticos-quirúrgicos y establecer una aso-ciación entre los tipos de síndrome presentes en pacientes con craneosinostosis sindrómica (CS). Material y métodos: Estudio retrospectivo de registros médicos y de ortodoncia de pacientes con CS. Los datos se recogieron en una forma específica y se sometieron a un análisis estadístico descriptivo para observar la distribución de frecuencias y se utilizó la prueba de Chi cuadrado con un nivel de significación del 5% para asociar el síndrome y los tipos de variables. Resultados: El síndrome de Crouzon fue el tipo predominante (59.2%) y la braquicefalia fue el tipo más frecuente de craneosinostosis (63.6%). Hubo una asociación significativa entre las variables braquicefalia (p = 0,014), presencia de paladar hendido (p = 0,043), mordida cruzada posterior (p = 0,013), distracción osteogénica realizada por elásticos intermaxilares (p = 0,030), barra de Erich (p = 0.007) y la extracción (p = 0.041) y los síndromes estudiados. Conclusión: Los pacientes con CS a menudo tienen cambios craneodentofaciais y algunas variables tienen asociaciones significativas en relación con los tipos de síndromes.

Objectives: Describe the craniodentofacial characteristics, orthodontic-surgical treatments and establish an association between the syndrome types present in patients with syndromic craniosynostosis (SC). Material and methods: Retros-pective study of medical and orthodontic records of patients with SC. Data was collected on a specific form and subjected to descriptive statistical analysis to observe the distribution of frequencies and chi-square test with level of significance of 5% was used to associate syndrome and the types of variables. Results: Crouzon syndrome was the predominant type (59.2%) and brachycephalia was the most prevalent type of craniosynostosis (63.6%). There was a significant association between the variables brachycephaly (p=0.014), presence of cleft palate (p=0.043), posterior cross bite (p=0.013), distrac-tion osteogenesis performed by intermaxillary elastics (p= 0.030), Erich bar (p= 0.007) and extraction (p=0.041) and the syndromes studied. Conclusion: Patients with SC often have craniodentofaciais changes and some variables had signifi-cant associations in relation to the types of syndromes.

Descrever as características craniodentofaciais, tratamentos ortodôntico-cirúrgicos e estabelecer uma associação entre os tipos de síndrome presentes em pacientes com craniossinostose sindrômica (CS). Material e métodos: Estudo retrospectivo de prontuários médicos e ortodônticos de pacientes com CS. Os dados foram coletados em formulário específico e submetidos à análise estatística descritiva para observar a distribuição das frequências e o teste qui-quadrado com nível de significância de 5% foi utilizado para associar a síndrome e os tipos de variáveis. Resultados: A síndrome de Crouzon foi o tipo predominante (59,2%) e a braquicefalia foi o tipo mais prevalente de craniossinostose (63,6%). Houve associação significativa entre as variáveis braquicefalia (p = 0,014), presença de fissura de palato (p = 0,043), mordida cruzada posterior (p = 0,013), distração osteogênica realizada pelos elásticos intermaxilares (p = 0,030), barra de Erich (p= 0,007) e extração (p = 0,041) e as síndromes estudadas. Conclusão: Pacientes com CS frequentemente apresentam alterações craniodentofaciais e algumas variáveis apresentaram associações significativas em relação aos tipos de síndromes.

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.

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.

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.

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.

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.

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.

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.

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

Abstract 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.

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.

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.

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.

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.