Elaine Vianna Freitas Fachin

Apical Transportation: A Comparative Evaluation of Three Root Canal Instrumentation Techniques with Three Different Apical Diameters

This study conducted an in vitro analysis of the level of apical transportation in mesiobuccal roots of upper molars after manual instrumentation with stainless steel files, preparation with the K3 system, and with a reciprocating NSK handpiece. Sixty roots were mounted in muffles and then longitudinally sectioned. A digital image was acquired of the inner surface of one root half. After instrumentation, the inner surfaces of the same root halves were digitized with file sizes #30, #35, and #40. Each image obtained was superimposed over the corresponding preoperative image, and the apical transportation was measured. The Friedman and Wilcoxon tests were used to compare results for the file sizes, and comparison of the groups was made with the Kruskal-Wallis test, demonstrating statistically significant differences (P = .000). The stainless steel file sizes #35 and #40 caused significant apical transportation, and K3 system proved safe for apical preparation, with little deviation.

Mineral Trioxide Aggregate–based Sealer: Analysis of Tissue Reactions to a New Endodontic Material

INTRODUCTION The aim of this study was to evaluate the subcutaneous connective tissue reaction to mineral trioxide aggregate (MTA)-based sealer (Endo CPM Sealer; CPM Sealer; EGEO SRL, Buenos Aires, Argentina), MTA, and an epoxy resin-based sealer (AH Plus; Dentsply HERO Indústria e Comércio Ltda, Petrópolis, RJ, Brazil). METHODS Polyethylene tubes containing the test materials and empty tubes (control group) were implanted in the subcutaneous tissue of 18 rats. After 7, 30, and 60 days, observations were made for cellular inflammatory components, fibrous condensation, and abscess formation. Comparisons between groups and periods of time were made using the Friedman test and the Kruskall-Wallis test. RESULTS Lymphocytes and plasmacytes were more intensely observed in the reaction to AH Plus sealer after 30 days (p < 0.05). MTA and the Endo CPM Sealer presented a behavior similar to that of the control group throughout the whole experiment. CONCLUSION The Endo CPM Sealer presented biological potential. Characteristics of the inflammatory reaction were equivalent to those produced by MTA.

Effect of betamethasone on the pulp after topical application to the dentin of rat teeth: vascular aspects of the inflammation

Objective: This study investigated the pulpal effect of topically applied betamethasone to the dentin of rat molars in the vascular phase of inflammation. Material and Methods: Deep cavities were prepared on the occlusal face of the maxillary right and left 1st molars with non-refrigerated inverted-cone steel burs at low speed. Three groups were formed: Group I was composed of right 1st molars; Group II was composed of left 1st molars that received the application of a drop of betamethasone on dentin surface for 5 min; and Group III (control) was composed of right 2nd molars that received no cavity preparation or betamethasone application. Changes in the vascular characteristics of the pulp tissue were checked by calculating the pulp vascular area in relation to its total area and the number of blood vessels per unit area. Data were subjected to ANOVA and Tukeys test (α=0.05). Results: Group I presented a significantly larger number of vessels (p<0.05) than Group II. Regarding the vascular/total area ratio (%), Group I presented statistically significantly higher values (p=0.01) than Groups II and III. Conclusion: Betamethasone applied on the dentin of rat teeth proved to reduce the vascular phase of pulp inflammation regarding vessel diameter and number of blood vessels.

Retreatment using a modified-tip instrument

The purpose of this article is to present a technique in which a modified file is used with reaming motion and apical pressure in retreatment cases.

Histology and Lysosomal Cytochemistry of the Postsurgically Inflamed Dental Pulp after Topical Application of Steroids. I. Histological Study

The purpose of this study was to histologically investigate steroid effects on the dental pulp. Three steroid preparations, hydrocortisone, betamethasone and triamcinolone, were locally applied to the exposed pulp tissue in rat incisor after pulpectomy. After 24 h, the effects on the tissues were assessed by light microscopy. The results showed that topical application of corticosteroids as an intracanal medicament reduced inflammatory changes in the pulp as compared with controls. Furthermore, triamcinolone and betamethasone demonstrated more potent anti-inflammatory effects than did hydrocortisone.

Apical transportation: Two assessment methods

Root canal transportation can lead to treatment failure. A large number of methodologies for assessing root canal preparation have been tried in the past. This study compared two methods for apical transportation measurement: digitised images of longitudinal root sections and radiographs. Sixty upper molar mesiobuccal root canals prepared for endodontic treatment were assessed. The results did not demonstrate statistically significant differences between the two imaging methods used to evaluate root canal transportation. The two methods were proven to be equally reliable.

Influence of smear layer removal on the obturation of root canal ramifications

Objective: This study evaluated whether smear layer removal has any influence on the filling of the root canal system, by examining the obturation of lateral canals, secondary canals and apical deltas. Material and Methods: Eighty maxillary and mandibular canines were randomly divided into two groups, according to their irrigation regimen. Both groups were irrigated with 1% NaOCl during canal shaping, but only the teeth in Group II received a final irrigation with 17% EDTA for smear layer removal. The root canals were obturated with lateral condensation of gutta-percha and the specimens were cleared, allowing for observation under the microscope. Results: In Groups I and II, 42.5% and 37.5% of the teeth, respectively, presented at least one filled canal ramification. Although a larger number of obturated ramifications was found in Group I, there were no statistically significant differences between the two groups (p = 0.4957). Conclusion: Smear layer removal under the conditions tested in this study did not affect the obturation of root canal ramifications when lateral condensation of gutta-percha was the technique used for root canal filling.

Permeabilidade dentinária como via terapêutica em endodontia - estudo in vitro

O objetivo deste estudo foi verificar a difusao do corticosteroide betametasona nos tubulos dentinarios. Em 28 dentes, terceiros molares extraidos, apos a realizacao de preparos cavitarios profundos nas faces oclusais, foi aplicada betametasona 0,5% em solucao aquosa, corada com azul-de-metileno 0,5%. Os dentes foram cortados longitudinalmente no sentido vestibulolingual. De acordo com o nivel de infiltracao, foram atribuidos escores para cada dente, variando de 0 a 4, sendo 0 sem infiltracao e 4 infiltracao maxima. Posteriormente, foi adaptado um papel-filtro ao teto da câmara pulpar e o medicamento foi reaplicado. Os resultados mostraram, no primeiro experimento, que o medicamento penetrou nos tubulos dentinarios de todos os dentes analisados, variando o nivel de infiltracao. Em 50% dos dentes o medicamento atingiu apenas o teto da câmara pulpar; em 28,6%, o teto e uma das paredes e em 3,6%, o teto e as duas paredes da câmara pulpar. Ja em 17,8% dos dentes, o medicamento atingiu o teto, o assoalho e as duas paredes da câmara pulpar. No segundo experimento o medicamento penetrou em 71,43% das amostras. Atribuem-se esses diferentes resultados ao fato de os dentes em que o medicamento nao penetrou terem sido marcados apenas pelo corante. Concluiu-se que a medicacao corticosteroide betametasona tem a potencialidade de se difundir pelos tubulos dentinarios e que suas propriedades terapeuticas, utilizando essa via de acesso, deveriam ser mais bem exploradas.