João Humberto Antoniazzi

Efficacy of Final Irrigation—A Scanning Electron Microscopic Evaluation

The purpose of this in vitro study was to determine the degree of removal of pulpal remnants and smear layer from root canals after final irrigation with three different solutions. During instrumentation the step-back preparation and 1% NaOCl were used. The final 4-min, 30-ml irrigation varied as follows: group I, 10 ml of 1% NaOCl + 10 ml of 10% citric acid + 10 ml of distilled water; group II, 15 ml of 0.5% NaOCl + 15 ml of EDTA-T; and group III, 10 ml of 5% NaOCl + 10 ml of 3% H2O2 + 10 ml of 5% NaOCl. Scanning electron microscopic photomicrographs were evaluated for the mean number of visible open dentinal tubules by three observers. The largest number of visible tubules in the three groups was in the cervical third, followed by the middle and apical thirds. There was no statistically significant difference between groups I and II when third was compared with third; however, groups I and II had significantly more visible dentinal tubules than group III.

Influence of different volumes of EDTA for final rinse on smear layer removal

OBJECTIVE The aim of this study was to analyze the influence of different volumes of 17% EDTA for final rinse on smear layer removal on the different areas of the root canal. STUDY DESIGN Forty single-rooted teeth were instrumented using rotary instruments. The teeth were divided into 3 test groups according to the EDTA volume for final rinse (5 mL, 10 mL, 15 mL) and 1 control group (10 mL of 1% sodium hypochlorite). The roots were axially split into halves, and the smear layer removal from the canals was determined under scanning electron microscope. The data were analyzed using Kruskal Wallis and Dunn tests. RESULTS The 3 experimental groups showed no statistical difference (P > .05); however, when the test groups were compared to the control group statistically significant differences were found (P < .01). The root canal wall surfaces of teeth in the control group showed the presence of heavy smear layer through the entire length of the root canals. The other groups showed mainly smear layer-free surfaces or a small amount of debris. When coronal, middle and apical thirds were compared, there was no statistically significant difference (P > .05). CONCLUSIONS Based on the results, it appears that a final rinse with 5 mL of EDTA per canal provides good smear layer removal, with root canal walls free of debris and mostly open dentinal tubules in all areas.

Collagen analysis in human tooth germ papillae

The extracellular matrix (ECM) performs a very important role in growth regulation and tissue differentiation and organization. In view of this, the purpose of this study was to analyze the collagen, the major organic component of dental pulp ECM, in papillae of human tooth germs in different developmental phases. The maxillas and mandibles of 9 human fetuses ranging from 10 to 22 weeks of intrauterine life were removed and 16 tooth germs (1 in the cap stage, 8 in the early bell stage and 7 in the late bell stage) were obtained. The pieces were processed for histological analysis and stained with hematoxylin-eosin, Massons Trichrome and picrosirius staining technique. Both types of collagen in the dental papilla were only detected by the picrosirius staining technique under polarized light microscopy. Type III collagen was detected in all specimens. Type I collagen was present in focal areas of the dental papilla only in some specimens. In conclusion, the findings of this study showed that type III collagen is a regular component of the papillae of human tooth germs whereas type I collagen is present in a significantly lesser amount.

Coronal and apical leakage analysis of two different root canal obturation systems

This study compared the coronal and apical leakage of AH Plus with gutta-percha to that of Epiphany with Resilon. Twenty-four single rooted teeth were instrumented and divided into 2 groups according to the solutions for smear layer removal and the obturation materials employed: Group A - 17% EDTA-T and AH Plus with gutta-percha; Group B - primer and Epiphany with Resilon. The Group B specimens were light-cured in the coronal area for 20 s. The external root surfaces were covered with a double layer of ethyl cyanoacrylate, except for the apical foramen and the cavity access. The teeth were immersed in 0.5% methylene blue for 48 h. The specimens were rinsed, dried and axially split for dye penetration measurement with the ImageLab 2.3 software. The t-test showed no significant differences for coronal leakage between the groups, but there were significant differences for apical leakage between the groups (P < 0.05). AH Plus with gutta-percha and Epiphany with Resilon provided the same coronal seal, whereas Epiphany with Resilon provided the best apical seal.

Influence of Er:YAG laser irradiation on apical sealing of four different sealers.

The sealing of the root canal system is of fundamental importance for successful endodontic treatment. To obtain an adequate apical seal, many factors must be considered such as the presence of smear layer and the sealer applied. After canal preparation, this layer must be removed because it prevents close contact between the dentinal walls and the sealing material. The goal of this study was to evaluate the sealing ability of four different sealers after smear layer removal with either 17% EDTA-T irrigation or Er:YAG laser irradiation of 46 teeth. The canals were sealed with four different sealers: Sealapex, Ketac Endo, AH Plus and N-Rickert. The method for smear layer removal did not influence apical sealing. AH Plus and N-Rickert allowed less dye leakage when compared to Sealapex and Ketac Endo.

Does a final rinse to remove smear layer interfere on dentin permeability of root canals

OBJECTIVE The objective of this study was to assess the influence of different final irrigating solutions on dentin permeability and smear layer removal using the same specimens and relate the results obtained. STUDY DESIGN Forty anterior human teeth were instrumented and divided into 4 groups (n = 10) at the final rinse step, according to the irrigant used: G I (control) - 1% NaOCl; G II - 17% EDTA; G III - 17% EDTAT; and G IV - Biopure MTAD. The canals were filled with 0.5% methylene blue and maintained in bottles for 48 hours. The roots were transversally split in coronal, middle, and apical fragments. The specimens were photographed and analyzed regarding dye penetration. The fragments were then axially split and prepared for SEM. The photomicrographs were analyzed and qualified by scores. RESULTS Only the EDTA-T group exhibited statistical difference in which the apical third had less dentin permeability (P < .05). When a decalcifying agent was used, smear layer was removed, which did not happen in the NaOCl group. Regarding smear layer removal, differences were found only in the EDTA group in which the apical third presented more smear layer (P < .05). No correlation was found for both studies (r = 0.4207). CONCLUSIONS There was not an even relationship between the results from both studies, which inferes that higher or lower dentinal permeability does not necessarily correspond to a higher or lower amount of smear layer. The analysis of dentin permeability and smear layer removal was shown to be a feasible procedure using the same specimens.

Presence of Voids after Continuous Wave of Condensation and Single-Cone Obturation in Mandibular Molars: A Micro-Computed Tomography Analysis

Introduction The objective of this study was to assess the presence of voids in mesial root canals of mandibular molar teeth obturated by using the single‐cone (SC) and continuous wave of condensation (CWC) obturation techniques, and results were analyzed by using micro–computed tomography. Methods Twenty‐four mandibular molars with fully developed roots and mesial root curvature ranging from 25° to 35° were instrumented by using Reciproc R25 files, and then they were obturated by using the SC and CWC techniques. Specimens were scanned before and after obturation for micro–computed tomography analysis (voxel size, 17.42 &mgr;m). After volumetric analysis and tridimensional reconstruction of the root canals, data were analyzed by using analysis of variance and the Tukey test. Results No significant differences were observed between the 2 techniques in terms of total percentage volume of voids: CWC = 3.91% ± 0.72%; SC = 6.52% ± 1.16% (P > .05). Only in the cervical third, CWC showed a significantly lower percentage of voids when compared with SC, namely 2.86% ± 0.94% vs 8.00% ± 1.86%, respectively (P < .05). Conclusions The percentage volume of voids was similar in the 2 groups and was influenced by the obturation technique only in the cervical third. HighlightsWe assessed the presence of voids in mesial root canals of mandibular molars after obturation.We compared the single‐cone and the continuous wave of condensation obturation techniques.Total percentage volume of voids was similar in the 2 groups.In the cervical third, CWC performed better.

The benefits and newly required practices brought about by innovations in the communication between professionals

In the last decades, communications was one of the areas of sciences that gained the most resourcefulness, with innovations of its own, and, above all, with the recent technological advances made available to an ever growing public. This resourcefulness has unquestionably contributed to scientific knowledge by facilitating the sharing of information between professionals. Unfortunately, however, this exchange can take on an illegal character, sometimes with questionable purposes. In the health care field, applying scientific knowledge often requires bringing different opinions together. This is particularly the case in Dentistry, owing to its inherent technical complexity. In order to choose the most appropriate conduct for each particular case – from diagnosing it properly to administering the most suitable therapy – it is necessary to acquire an overall picture based on experienced opinions that look at the problem from various standpoints and with different levels of knowledge. This process of querying and consolidation is called “Second Opinion”, which can be more easily shared today because of the constant innovation in the communication media. An important aspect in this issue is preserving the relationship between patient and dental professional, observing the principles of secrecy, individuality, confidentiality and both personal and delegated property. The exclusive and indivisible responsibility of the professional that provides care to the patient in a direct and personal fashion stands unquestioned. Other concurring professionals merely contribute to the process of building the best possible judgment by the first professional. These are the underlying circumstances guiding the cautionary measures required in the relationship between the professional directly involved in seeing the patient and the professional providing a second opinion to assist in the case directly or at a distance via internet, whether formally or informally. The ethical responsibility of those who send and receive protocols, images, case reports and other data pertaining to the case – including lab information and data used by lab professionals – is at stake. Here, the required ethical conduct is the same as that recommended in working with any other database, whether physical, digital or of any other nature. Digital databases should be set up with the same secrecy and reliability as physical ones. Encrypting the information will allow access solely and exclusively by those who have the correct passwords and code keys, but it also involves the costs of building access environments run by encryption systems. On the other hand, the simple exchange of email mesMary Caroline Skelton Macedo(a) João Humberto Antoniazzi(b)

POSICIONADOR RADIOGRÁFICO PERSONALIZADO PARA CONTROLE DO TRATAMENTO ENDODÔNTICO

O estudo das imagens do dente em tratamento endodontico e das suas estruturas anexas favorece a identificacao precoce das alteracoes capazes de comprometer o prognostico de sucesso. A perfeita informacao radiografica e a correta interpretacao comprovadamente orientam a conduta terapeutica, estreitando a relacao entre a cura e a patologia. Assim sendo, e devido a importância da fidelidade desse procedimento, os autores apresentam um dispositivo que, acoplado a qualquer posicionador comercializado, possibilita a tomada de imagens semelhantes sob o aspecto das suas dimensoes. A importância desse fato surgiu da necessidade do confronto das imagens obtidas entre as sessoes do tratamento. Os estudos clinicos indicaram que o posicionador personalizado obtido atraves de moldagem com material pesado favoreceu sensivelmente as analises comparativas das areas da superficie radicular externa acometidas de reabsorcao cemento-dentinaria, como sequela de trauma dental, bem como as regioes portadoras de rarefacao ossea periapical no decorrer da avaliacao da neoformacao.

Ozone therapy as an adjuvant for endondontic protocols: microbiological – ex vivo study and citotoxicity analyses

ABSTRACT Objectives This study evaluated the antimicrobial efficacy of ozone therapy in teeth contaminated with Pseudomonas aeruginosa, Enterococcus faecalis, and Staphylococcus aureus using a mono-species biofilm model. Parallel to this, the study aimed to evaluate the cytotoxicity of ozone for human gingival fibroblasts. Material and Methods: One hundred and eighty single-root teeth were contaminated with a mono-species biofilm of Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus. Groups were formed: Group I – control; Group II – standard protocol; Group III – standard protocol + ozone gas at 40 µg/mL; and Group IV – standard protocol + aqueous ozone at 8 µg/mL. In parallel, human gingival fibroblasts were submitted to the MTT test. Cells were plated, then ozone was applied as follows: Group I (control) – broth medium; Group II – aqueous ozone at 2 µg/mL; Group III – aqueous ozone at 5 µg/mL; and Group IV – aqueous ozone at 8 µg/mL. Data were submitted to the Kruskal Wallis test and Bonferroni post hoc analyses to assess microbiology and cytotoxicity, respectively (p<0.05%). Results The results revealed antimicrobial efficacy by Group IV with no CFU count. The cytotoxicity assay showed Groups III and IV to be the most aggressive, providing a decrease in cell viability at hour 0 from 100% to 77.3% and 68.6%, respectively. Such a decrease in cell viability was reverted, and after 72 hours Groups III and IV provided the greatest increase in cell viability, being statistically different from Groups I and II. Conclusion According to the applied methodology and the limitations of this study, it was possible to conclude that ozone therapy improved the decontamination of the root canal ex vivo. Ozone was toxic to the cells on first contact, but cell viability was recovered. Thus, these findings suggest that ozone might be useful to improve root canal results.