Effect of sonic and ultrasonic activation on physicochemical properties of root canal sealers

Abstract Objective: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. Methodology: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers' instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). Results: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. Conclusions: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling.

Evaluation of the physicochemical properties of silicone- and epoxy resin-based root canal sealers

Abstract To assess the physicochemical properties of AH Plus, GuttaFlow 2, GuttaFlow BioSeal, and MM Seal, five samples of each root canal sealer were evaluated to determine their setting time (ST), dimensional change (DC), solubility (SL), flow (FL), and radiopacity (RD) according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 57. The distilled and deionized water obtained from the SL test were subjected to atomic absorption spectrometry to observe the presence of Ca2+, K+, and Na+ ions. Statistical analysis was performed by using one-way ANOVA and Tukey-Kramer tests (p < 0.05). The following results were obtained: ST (min) (AH Plus 463.6 ± 13.22; GuttaFlow 2 24.35 ± 2.78; GuttaFlow Bioseal 17.4 ± 0.55; MM Seal 47.60 ± 4.39), DC (%) (AH Plus 0.06 ± 0.12; GuttaFlow 2 −26.06 ± 1.24; GuttaFlow Bioseal 2.10 ± 1.47; MM Seal 8.47 ± 2.41), SL (%) (AH Plus 0.41 ± 0.21; GuttaFlow 2 5.13 ± 4.11; GuttaFlow Bioseal 3.03 ± 1.05; MM Seal 0.94 ± 0.17), FL (mm) (AH Plus 36.42 ± 0.40; GuttaFlow 2 36.44 ± 0.05; GuttaFlow Bioseal 35.4 ± 0.03; MM Seal 52.75 ± 0.60), and RD (mmAl) (AH Plus 7.52 ± 1.59; GuttaFlow 2 6.85 ± 0.14; GuttaFlow Bioseal 7.02 ± 0.18; MM Seal 3.32 ± 0.90). ST, DC, SL, FL, and RD showed statistical differences among the root canal sealers (p < 0.05). As AH Plus showed the lowest DC and SL values (p < 0.05), the findings indicate that this sample is the only sealer conforming to ANSI/ADA standards.

In vitro antibacterial activity of a silicone-based endodontic sealer and two conventional sealers

Abstract The aim of this study was to evaluate whether the modification in the silver component is capable of providing GuttaFlow 2 with antibacterial activity against Enterococcus faecalis compared with epoxy resin-based (AH Plus) and zinc oxide and eugenol-based (Endofill) sealers. The antibacterial activity was evaluated using a reference strain of E. faecalis (ATCC 29212). Freshly mixed sealers were subjected to the agar diffusion test (ADT), while the direct contact test (DCT) was performed after materials setting. ADT results were obtained through measurements, in millimeters, of the inhibition zones promoted by the materials, using a digital caliper. In DCT, values of CFU/mL promoted by the three sealers were compared in three experimental periods (1 min, 1 h, and 24 h). The data were analyzed using Kruskal-Wallis and Dunn post-hoc tests (p < 0.05). In both ADT and DCT, GuttaFlow 2 presented no effect against E. faecalis, while Endofill and AH Plus showed similar inhibition zones. Endofill was the only material capable of reducing bacterial growth in DCT. In conclusion, modifications in the silver particle of GuttaFlow 2 did not result in a sealer with antibacterial effect against E. faecalis.

Sequela de injeção de silicone em lábio inferior: correção cirúrgica pela técnica do biquíni modificada / Sequelae of inferior lip silicone injection: surgical correction using the modified "bikini" technique

Pacientes portadores de sequelas devido a injeções de substâncias inabsorvíveis tem se tornado cada vez mais frequentes. O silicone injetável ou polidimetilsiloxano fluido é um polímero manufaturado que contém silicone elementar. As complicações consequentes ao uso desta substância podem ser precoces ou tardias. Apresentamos um relato de caso onde uma deformidade por injeção de silicone em lábios foi tratada cirurgicamente usando a técnica do biquíni modificada obtendo um bom resultado funcional e estético.

Increasing numbers of patients have sequelae due to the injection of non-absorbable substances. Injectable silicone or polydimethylsiloxane fluid is a manufactured polymer containing elemental silicon. The complications associated with the use of this substance can present early or late. Here we present a case report in which a deformity due to a silicone injection in the lips was surgically treated using the modified "bikini" technique that produced a functionally and aesthetically favorable result.

Effect of different disinfecting procedures on the hardness and color stability of two maxillofacial elastomers over time

Objective Disinfection procedures often cause deterioration in a maxillofacial prosthesis. Color and hardness alterations could lead to a replacement of the prosthesis. Material and Methods An experimental chlorinated polyethylene (CPE) and a commercial polydimethyl siloxane (PDMS) sample were treated with four different disinfection procedures for a period which simulates 1 year of clinical service. The applied disinfection procedures included microwave exposure and immersion in three solutions, sodium hypochlorite, neutral soap and a commercial disinfecting soap. Shore A hardness (∆H) and color differences (∆E) were determined before and after each procedure. All data were analyzed by Two Way Analysis of Variance (ANOVA) and Tukey's post hoc tests at a level of α=0.05. Results The samples presented significant alterations in color and hardness after the different disinfection treatments. The color differences (∆E) were at least eye detectable in all cases and clinically unacceptable in most of the cases, with values ranging from 1.51 to 4.15 and from 1.54 to 5.92 for the PDMS and CPE material, respectively. Hardness was decreased after all the disinfection procedures in the PDMS, while for the CPE, a decrement was observed after disinfection with sodium hypochlorite and neutral soap and an increment after microwave exposure and the disinfection with a commercial antimicrobial agent. The PDMS samples presented greater alterations in color and hardness after disinfection with sodium hypochlorite solution, while the microwave exposure caused negligible effects. The CPE samples were affected most after disinfection when treated with neutral soap, and more slightly when disinfected with sodium hypochlorite solution. Conclusions The disinfection procedures caused alterations in color and hardness of the examined materials. The most suitable disinfection procedure for ...

Hardness evaluation of prosthetic silicones containing opacifiers following chemical disinfection and accelerated aging

We evaluated the effects of disinfection and aging on the hardness of silicones containing opacifiers and intended for use in facial prosthetics. A total of 90 samples were produced using a cylindrical metal mold 3 mm in height and 30 mm in diameter. The samples were fabricated from Silastic MDX 4-4210 silicone in three groups: GI contained no opacifier, GII contained barium sulfate (Ba), and GIII contained titanium dioxide (Ti). The samples were disinfected using effervescent tablets (Ef), neutral soap (Ns), or 4 percent chlorhexidine (Cl) 3 times a week for 60 days. After this period the samples underwent 1,008 hours of accelerated aging. The hardness was measured using a durometer immediately following the disinfection period and after 252, 504, and 1,008 hours of aging. The data were statistically analyzed using 3-way ANOVA and the Tukey test (p < .05). The GIII group exhibited the greatest variation in hardness regardless of elapsed time. All groups displayed greater hardness after 1,008 hours of accelerated aging independent of disinfectant type. All of the hardness values were within the clinically acceptable range.

Evaluation of single root canals filled using the lateral compaction, tagger's hybrid, microseal and guttaflow techniques

The aim of this study was to determine the percentage of voids, gutta-percha and root canal sealer using 4 different filling techniques. Fifty-two extracted maxillary lateral incisors were prepared using the crown-down pressureless technique. The teeth were randomly divided in 4 groups (n=13): Lateral compaction (LC), Tagger's hybrid (TH), MicroSeal (MS) and GuttaFlow (GF) techniques. Horizontal cross-sections were made at the 2, 10 and 15 mm levels from the apex. Digital images of the root canal areas were acquired using a stereomicroscope and examined using the Image Tool 3.0 software. Statistical analysis was performed using the Kruskal-Wallis test (α=0.05). In general, a significant decrease in the gutta-percha filled area and increase of sealer area were observed at the apical level for all the evaluated techniques (p<0.05). With regard to the presence of voids, no significant difference was found. MS and TH techniques showed a larger gutta-percha filled area than LC and GF techniques at the coronal and middle third level (p<0.05). From the results of the present study, it may be concluded that the gutta-percha filled area of fillings decrease at the apical level, regardless of the filling technique used.

O objetivo do estudo foi determinar a porcentagem de espaços vazios, guta-percha e cimento após a obturação por 4 diferentes técnicas. Cinquenta e dois incisivos laterais superiores humanos extraídos foram instrumentados pela técnica coroa-ápice sem pressão. Os dentes foram randomicamente divididos em 4 grupos (n=13): Condensação lateral (LC), Técnica híbrida de Tagger (TH), MicroSeal (MS) e GuttaFlow (GF). Foram feitas secções horizontais a 2, 10 e 15 mm do ápice. Imagens digitais foram obtidas dos canais por meio de estereomicroscópio e analisadas no programa Image Tool 3.0. A análise estatística foi feita utilizando o teste de Kruskal-Wallis (α=0,05). Em geral foi observado um significante decréscimo na área de guta-percha e um aumento na área de cimento para todas as técnicas analisadas (p<0,05). Com relação à presença de espaços vazios, não houve diferença estatística entre as técnicas (p>0,05). As técnicas MS e TH apresentaram área de guta-percha maior que as técnicas LC e GF nos terços médio e cervical (p<0,05). Após análise dos resultados foi possível concluir que a área de guta-percha nas obturações diminui em sentido apical, independente da técnica utilizada.

Effect of conventional and experimental gingival retraction solutions on the tensile strength and inhibition of polymerization of four types of impression materials

In the present study, two types of tests (tensile strength test and polymerization inhibition test) were performed to evaluate the physical and chemical properties of four impression materials [a polysulfide (Permlastic), a polyether (Impregum), a condensation silicone (Xantopren) and a polyvinylsiloxane (Aquasil) ,3; when polymerized in contact with of one conventional (Hemostop) and two experimental (Vislin and Afrin) gingival retraction solutions. For the tensile strength test, the impression materials were mixed and packed into a steel plate with perforations that had residues of the gingival retraction solutions. After polymerization, the specimens were tested in tensile strength in a universal testing machine. For the polymerization inhibition test, specimens were obtained after taking impressions from a matrix with perforations that contained 1 drop of the gingival retraction solutions. Two independent examiners decided on whether or not impression material remnants remained unpolymerized, indicating interference of the chemical solutions. Based on the analysis of the results of both tests, the following conclusions were reached: 1. The tensile strength of the polysulfide decreased after contact with Hemostop and Afrin. 2. None of the chemical solutions inhibited the polymerization of the polysulfide; 3. The polyether presented lower tensile strength after polymerization in contact with the three gingival retraction agents; 4. The polyether had its polymerization inhibited only by Hemostop; 5. None of the chemical solutions affected the tensile strength of the condensation silicone; 6. Only Hemostop inhibited the polymerization of the condensation silicone; 7. The polyvinylsiloxane specimens polymerized in contact with Hemostop had significantly lower tensile strength; 8. Neither of the chemical solutions (Afrin and Vislin) affected the tensile strength of the polyvinylsiloxane and the condensation silicone; 9. Results of ...

Comparative study of the sealing ability of a polydimethylsiloxane-based root canal sealer

O objetivo deste estudo foi comparar a capacidade de selamento de três cimentos endodônticos, RSA (cimento à base de silicone), Endion (cimento à base de ionômero de vidro) e Topseal (cimento à base de resina epóxica), com e sem remoção de smear layer. Noventa dentes humanos extraídos foram selecionados e distribuídos em 6 grupos (n=15), de acordo com os seguintes protocolos: em 3 grupos, a smear layer foi mantida e os canais radiculares foram obturados com cones de guta-percha e com os cimentos RSA, Endion e Topseal, respectivamente. Nos outros 3 grupos, a smear layer foi removida e os canais radiculares foram obturados da mesma forma. A microinfiltração foi avaliada aos 7 dias, 1 mês e 2 meses, utilizando o sistema de transporte de fluído. Os resultados foram expressos em µL/24 h. Os dados foram analisados estatisticamente por meio dos testes não-paramétricos de Kruskall-Wallis e Mann-Whitney. Os resultados demonstraram que o grupo obturado com Topseal sem smear layer apresentou infiltração significativamente menor (p<0.05) que o grupo obturado com cimento RSA sem smear layer, em todos os períodos avaliados. Não houve diferença estatisticamente significante (p>0.05) entre os outros grupos, nos intervalos de avaliação estabelecidos. Os achados deste estudo demonstraram que o cimento à base de silicone (RSA) não apresentou melhor capacidade de selamento que os outros cimentos, na presença ou ausência de smear layer. Dentre os cimentos endodônticos avaliados, o Topseal apresentou os menores valores de microinfiltração.