Assessment of a Cavity to Optimize Ultrasonic Efficiency to Remove Intraradicular Posts.

INTRODUCTION: The study assessed an in vitro protocol for the removal of cast metal posts using ultrasonic vibration in multirooted teeth by drilling a cavity in the coronal portion of the post followed by ultrasound application in the cavity. METHOD: Forty endodontically treated molars received intraradicular cast posts and were divided into 4 groups according to the removal protocol: the control group, no cavity and no ultrasonic vibration; the ultrasonic group, no cavity and ultrasonic vibration in the coronal portion of the core; the cavity group, a cavity in the core and no ultrasonic vibration; and the cavity ultrasonic group, a cavity in the core and ultrasonic vibration inside the cavity. The traction test was performed on all samples using a universal testing machine (EMIC DL-2000; EMIC Equipamentos e Sistemas de Ensaio LTDA, São José dos Pinhais, PR, Brazil) at a speed of 1 mm/min, obtaining values in Newtons. The data were statistically analyzed using analysis of variance and the Tukey-Kramer test (P < .05). RESULTS: The results showed statistically significant differences between the tested groups (control group = 322.74 N, ultrasonic group = 283.09 N, cavity group = 244.00 N, and cavity ultrasonic group = 237.69 N). The lowest mean strength was found in the group that received ultrasonic vibration inside the cavity. CONCLUSIONS: Preparing a cavity in the coronal core followed by ultrasonic vibration reduces the traction force required for removal. The removal protocol was effective for removing posts in multirooted teeth cemented with zinc phosphate.

Apical Transportation, Centering Ability, and Cleaning Effectiveness of Reciprocating Single-file System Associated with Different Glide Path Techniques.

INTRODUCTION: The aim of this study was to evaluate the apical transportation, the centering ability, and the cleaning effectiveness of a reciprocating single-file system associated to different glide path techniques. METHODS: The mesial root canals of 52 mandibular molars were randomly distributed into 4 groups (n = 13) according to the different glide path techniques used before biomechanical preparation with Reciproc System (RS): KF/RS (sizes 10 and 15 K-files), NGP/RS (no glide path, only reciprocating system), PF/RS (sizes 13, 16, and 19 PathFile instruments), and NP (no preparation). Cone-beam computed tomography analysis was performed before and after instrumentation for apical third images acquisition. Apical transportation and its direction were evaluated by using the formula D = (X1 - X2) - (Y1 - Y2), and the centering ability was analyzed by the formula CC = (X1 - X2/Y1 - Y2 or Y1 - Y2/X1 - X2). The samples were submitted to histologic processing and analyzed under a digital microscope for debris quantification. The values were statistically analyzed (Kruskal-Wallis, the Dunn multiple comparisons test, P < .05). RESULTS: All groups had similar apical transportation values, with no significant difference among them (P > .05). Groups had a tendency toward transportation in the mesial direction. No technique had perfect centering ability (=1.0), with no significant difference among them. KF/RS had larger amount of debris, with statistically significant difference in comparison with NGP/RS (P > .05). CONCLUSIONS: The different glide path techniques promoted minimal apical transportation, and the reciprocating single-file system tested remained relatively centralized within the root canal. Also, the different techniques interfered in the cleaning effectiveness of the reciprocating system.

Cytotoxicity evaluation of a copaiba oil-based root canal sealer compared to three commonly used sealers in endodontics.

BACKGROUND: The constant development of new root canal sealers has allowed the solution of a large number of clinical cases in endodontics, however, cytotoxicity of such sealers must be tested before their validation as filling materials. The aim of this study was to evaluate the cytotoxic effect of a new Copaiba oil-based root canal sealer (Biosealer [BS]) on osteoblast-like Osteo-1 cells. MATERIALS AND METHODS: The experimental groups were formed according to the culture medium conditioned with the tested sealers, as follows: Control group (CG) (culture medium without conditioning); Sealer 26 (S26) - culture medium + S26; Endofill (EF) - culture medium + EF; AH Plus (AHP) - culture medium + AHP; and BS - culture medium + BS (Copaiba oil-based sealer). The conditioned culture medium was placed in contact with 2 × 10(4) cells cultivated on 60 mm diameter Petri dishes for 24 h. Then, hemocytometer count was performed to evaluate cellular viability, using Trypan Blue assay. The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for cellular viability were statistically analyzed (1-way ANOVA, Tukey's test - P < 0.05), with a significance level of 5%. RESULTS: S26, EF and AHP presented decreased cellular viability considerably, with statistical significance compared with CG (P < 0.05). BS maintained cellular viability similar to CG (P > 0.05). CONCLUSION: The Copaiba oil-based root canal sealer presented promising results in terms of cytotoxicity which indicated its usefulness as a root canal sealer.

Evaluation of a new protocol for removing metal retainers from multirooted teeth.

INTRODUCTION: The aim of this study was to evaluate in vitro a new protocol for removing intraradicular retainers from multirooted teeth applying ultrasonic vibration. METHODS: Forty mandibular molars were endodontically treated to receive cast intraradicular retainers, which were distributed into the following 4 groups: group 1: control without a slot and without ultrasound, group 2: control with a slot and without ultrasound, group 3: ultrasonic vibration in the core without a slot, and group 4: ultrasonic vibration in the core with a slot. After the intraradicular retainers were cemented with zinc phosphate, ultrasonic vibration was applied for 1 minute. The test specimens were then submitted to the traction test in the universal testing machine at a speed of 1 mm/min. The maximum traction force required to remove the intraradicular retainer was recorded in newtons, and the data were statistically analyzed using analysis of variance and the Tukey-Kramer test (P < .05). RESULTS: The results showed statistically significant differences among the groups tested (group 1 = 234.34 N, group 2 = 201.67 N, group 3 = 139.57 N, and group 4 = 83.23 N). The lowest mean value of traction force recorded was when ultrasonic vibration was applied on the core with a slot. CONCLUSIONS: Creating a slot in the core and the ultrasound application on all surfaces and inside the slot reduced the force required for removing intraradicular metal retainers from multirooted teeth cemented with zinc phosphate.

Avaliação in vitro da atividade antimicrobiana de pastas endodônticas à base de extrato glicólico de Musa paradisiaca frente a Enterococcus faecalis / In vitro evaluation of the antimicrobial activity of endodontic pastes made of Musa paradisiaca glycolic extract over Enterococcus faecalis

Os produtos de Musa paradisiaca (bananeira) são usados como sedativo para odontalgia, cicatrizante de feridas cirúrgicas de exodontia, úlcera gástrica, entre outras indicações em comunidades que têm por tradição o uso das plantas como Medicina alternativa. Na Endodontia, almeja-se uma medicação intracanal ideal contra cepas resistentes em infecções endodônticas refratárias. Por esse motivo, o objetivo desse trabalho foi testar a atividade antimicrobiana do extrato glicólico de Musa paradisiaca (Mp) sobre Enterococcus faecalis (Ef). Para realizar o experimento, o extrato glicólico de Musa paradisiaca (EGB) substituiu o Polietilenoglicol 400 (PEG), que é um veículo que compõe algumas medicações intracanal. Foi utilizado o teste de difusão em ágar, pelo método do poço, para a avaliação da atividade antimicrobiana contra a cepa de Ef, normalmente relacionada a infecções refratárias endodônticas. Experimento “A”: G1, PEG (controle negativo); G2, PEG e Ca(OH) 2 ; G3, EGB; G4, EGB e Ca(OH) 2 e G5, gel de clorexidina 2% (CHX – controle positivo). Experimento “B”: G1, PEG (controle negativo); G2, PEG e ZnO; G3, PEG, Ca(OH) 2 e ZnO; G4, EGB e ZnO; G5, EGB, Ca(OH) 2 e ZnO e G6, CHX (controle positivo). Apenas a pasta de EGB e ZnO obteve atividade antimicrobiana estatisticamente significante, podendo ser uma propriedade importante para a composição de medicação intracanal. Todo novo biomaterial baseado na etnobotânica deve ser testado criteriosamente para viabilizar sua aplicabilidade clínica, o que justificou a pertinência deste estudo preliminar. No entanto, testes físico-químicos e de biocompatibilidade são imprescindíveis para futuro emprego de fitoterápicos na Endodontia

The products of Musa paradisiaca (banana plantain) are used as a sedative for dental pain, healing of tooth extraction surgical wounds, gastric ulcer, among other indications in communities that have the tradition of using plants as alternative Medicine. Endodontics searchs for an ideal intracanal medication for resistant strains on refractory endodontic infections. Therefore, the objective of this study was to test the antimicrobial activity of Musa paradisiaca (Mp) glycolic extract over Enterococcus faecalis (Ef). To perform the experiment, the Polyethyleneglycol 400 (PEG), used to make some intracanal medication, was replaced by Musa paradisiaca glycolic extract. Agar well diffusion test was used to evaluate antimicrobial activity over Ef. Strains normally related to refractory endodontic infections. Experiment “A”: G1, PEG (negative control); G2, PEG and Ca(OH)2; G3, EGB; G4, EGB and Ca(OH)2; and G5, 2% chlorhexidine gel (CHX - positive control). Experiment “B”: G1, PEG (negative control); G2, PEG and ZnO; G3, PEG, Ca(OH)2 and ZnO; G4, ZnO and EGB; G5, EGB, Ca(OH)2 and ZnO; and G6, CHX (positive control). Only the EGB and ZnO paste has obtained statistically significant antimicrobial activity, indicating that it can be an important property for a new intracanal medication. Every new biomaterial based on ethnobotanic should be carefully tested to allow its clinical applicability reinforcing the relevance of this preliminary study. However, physicochemical and biocompatibility tests are essential to future utilization of herbal medicines in Endodontics

Management of dens invaginatus type III with large periradicular lesion.

AIM: This study describes a clinical case of type III dens invaginatus with an extensive periradicular lesion treated successfully. BACKGROUND: Dens invaginatus is a maldevelopment of the dental germ which occurs as a result of the invagination of the enamel organ. These cases may present difficulties with respect to its diagnosis and treatment because of canal morphology. The success of endodontic therapy requires a knowledge of dental anatomy and its anomalies. CASE REPORT: A 17-year-old female patient is reported presenting right maxillary lateral incisor (tooth no. 7) classified as type III dens invaginatus with necrotic pulp and presence of an extensive radiolucid lesion. Endodontic treatment was recommended for tooth. However, intracanal exudate was present, suggesting a resistant infection. Enucleation of the lesion was performed as a complementary approach. The root canal obturation was carried out by the gutta-percha thermoplastification technique with root canal sealer, followed by restoration of the tooth. Healing of the lesion with hard tissue formation was confirmed at follow-up. CONCLUSION: A combination of endodontic and surgical treatments were fundamental to the maintenance of the tooth. The treatment was considered successful. CLINICAL SIGNIFICANCE: Root canal therapy of dens invaginatus should be based on a thorough clinical and radiographic evaluation. The knowledge of classification and anatomical variations of teeth with dens invaginatus are of great importance for correct treatment.

Tip diameter of 0.04 and 0.06 tapered gutta-percha points from different commercial brands / Diâmetro da ponta (d0) de cones de guta-percha de conicidades 0, 04 e 0, 06 de diferentes marcas comerciais

Objective: The aim of this study was to determine the correlation between the diameter D0 of guttapercha points from three different commercial brands (Tanari Man, Cone Tech and Dentsply) and their original respective values. Materials and methods: A high precision micrometer was used by a single calibrated operator to evaluate if the gutta-percha points are in aggrement with the n. 57 ANSI/ADA specification. Results: For the 0.04 tapered points, Cone Tech showed lower percentage of inadequate points (52%), followed by Dentsply (56%) and Tanari (80%). For the 0.06 tapered points, Cone Tech showed lower percentage of inadequate points (50%), followed by manufacturers Dentsply (53%) and Tanari (81%). Conclusions: It can be concluded that there is no standardization in the diameter D0 of the gutta-percha points of different commercial brands.

Objetivo: O objetivo deste estudo foi determinar a correlação entre o diâmetro D0 dos cones de guta-percha detrês diferentes marcas comerciais (Tanari Man, Cone Tech e Dentsply) com seus respectivos valores originais. Materiais e métodos: Um micrômetro de alta precisão foi utilizado por um único operador devidamente calibradopara avaliar se os cones de guta-percha estavam de acordo com a norma n. 57 da ANSI/ADA. Resultados:Para a conicidade 0.04, Cone Tech apresentou menor percentual de cones inadequados (52%), seguido deDentsply (56%) e Tanari (80%). Para a conicidade 0.06, Cone Tech apresentou menor percentual de conesinadequados (50%), seguido de Dentsply (53%) e Tanari (81%). Conclusões: Pôde-se concluir que não há padronizaçãono diâmetro D0 dos cones de guta-percha das diferentes marcas comerciais.

Dimensional alterations and solubility of new endodontic sealers.

This study evaluated the dimensional alterations and the solubility of two experimental endodontic sealers based on Copaifera multijuga oil-resin (Biosealer) and castor oil bean cement (Poliquil), maintained in different storage solutions. Twenty specimens (3 mm diameter and 2 mm height) of each sealer were assigned to 2 groups (n=10) according to the storage solution: simulated tissue fluid (STF) or distilled water (DW). The specimens were stored in these solutions during 90 days, being removed every 30 days for weighting. The solutions were renewed every 15 days. The results were subjected to statistical analysis by Dunn's and Mann-Whitney tests (a=0.05). The solubility of Poliquil was higher in STF (38.4 ± 36.0) than in DW (28.4 ± 15.0), while Biosealer showed higher solubility in DW (34.61 ± 6.0) than in STF (18.59 ± 8.0). The storage solution influenced the behavior of sealers in relation to the weight variation (p=0.0001). Poliquil presented higher variation of weight independent of the solution (p=0.239). Biosealer also presented higher variation of weight regardless of the solution (p=0.0001). The solubility of Biosealer was different from that of Poliquil, but both sealers showed low solubility in STF. Under the tested conditions, neither of the materials were according to the ADA'S specification.

Dimensional alterations and solubility of new endodontic sealers

This study evaluated the dimensional alterations and the solubility of two experimental endodontic sealers based on Copaifera multijuga oil-resin (Biosealer) and castor oil bean cement (Poliquil), maintained in different storage solutions. Twenty specimens (3 mm diameter and 2 mm height) of each sealer were assigned to 2 groups (n=10) according to the storage solution: simulated tissue fluid (STF) or distilled water (DW). The specimens were stored in these solutions during 90 days, being removed every 30 days for weighting. The solutions were renewed every 15 days. The results were subjected to statistical analysis by Dunn's and Mann-Whitney tests (a=0.05). The solubility of Poliquil was higher in STF (38.4 ± 36.0) than in DW (28.4 ± 15.0), while Biosealer showed higher solubility in DW (34.61 ± 6.0) than in STF (18.59 ± 8.0). The storage solution influenced the behavior of sealers in relation to the weight variation (p=0.0001). Poliquil presented higher variation of weight independent of the solution (p=0.239). Biosealer also presented higher variation of weight regardless of the solution (p=0.0001). The solubility of Biosealer was different from that of Poliquil, but both sealers showed low solubility in STF. Under the tested conditions, neither of the materials were according to the ADA'S specification.

O presente estudo avaliou a alteração dimensional e solubilidade de 2 cimentos experimentais (à base de resina do óleo de Copaíba - Biosealer e cimento do polímero da mamona - Poliquil), mantidos em diferentes meios de armazenamento. Foram confeccionados 20 espécimes de cada cimento com 3 mm de diâmetro e 2 mm de altura os quais foram divididos em 2 grupos (n=10) de acordo com o meio de armazenamento (fluido tissular simulado ou água destilada). Os espécimes foram atidos nas soluções durante 90 dias, sendo removidos a cada 30 dias para pesagem das amostras, no entanto as soluções foram trocadas a cada 15 dias. Os resultados foram submetidos aos testes de Dunn (5 por cento) e Mann-Whitney. Os meios de armazenamento causaram influência no comportamento dos cimentos em relação ao peso (p=0,0001). Poliquil apresentou alta variação de peso independente da solução (p=0,239). Biosealer também apresentou alta variação de peso independente da solução (p=0,0001). A solubilidade do Biosealer foi diferente do Poliquil, entretanto, ambos cimentos mostraram baixa solubilidade no fluido tissular simulado. Nas condições do experimento, nenhum cimento está de acordo com a especificação da ADA.

Evaluation of root external temperature during the application of ultrasound in removal of intraradicular posts.

This study evaluated the temperature rise on external root surfaces by simulating the removal of metallic posts by applying ultrasound, with or without refrigeration and at different times. The crowns of 30 healthy maxillary central incisors were removed and the roots were treated endodontically. The prosthetic spaces were prepared and impressions were taken with self-curing acrylic resin. After casting with a copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with resin cement. The specimens were randomly assigned to three groups according to the time of ultrasonic vibration (30, 60, or 120 seconds) and were subdivided into two groups, those cooled with and without water refrigeration. A thermocouple connected to a digital thermometer was positioned on the root external surface and the maximum temperature was recorded. Data were submitted to ANOVA and Tukey's test. Analysis of the results revealed statistical difference among groups (p < 0.01). Ultrasound (with and without water spray) increased root temperature significantly, reaching values of more than 50 degrees C. The exception was the group that used 30 seconds of ultrasound with refrigeration; root temperature reached 35.4 degrees C, making it the only tested condition that remained below the critical value (50 degrees C).

Influence of ultrasound, with and without water spray cooling, on removal of posts cemented with resin or zinc phosphate cements.

The efficacy of ultrasound, with and without water spray, was evaluated in vitro on the amount of force necessary to dislodge posts cemented with resin or zinc phosphate. Forty-two samples were divided into six groups: groups 1, 2, and 3, posts cemented with zinc phosphate; groups 4, 5, and 6, posts cemented with resin (Panavia F); groups 1 and 4 (controls), no ultrasound; groups 2 and 5, ultrasound without water spray; and groups 3 and 6, ultrasound with water spray. The Instron testing machine was used. Ultrasound without water spray significantly reduced (71%) the force necessary to displace posts cemented with Panavia F (p < 0.01); however, this value was similar to the efficacy of ultrasound with water spray for posts cemented with zinc phosphate (reduction of 75%). We conclude that cooling with ultrasound interferes with the force necessary for post removal, depending on the type of cement used.