Avaliação da microinfltração coronária de três materiais utilizados na restauração provisória da cavidade endodôntica: estudo in vitro. / Coronal leakage of three materials used for temporary restoration of endodontic access cavities: an in vitro study

O objetivo deste trabalho foi avaliar a capacidade seladora de um material restaurador provisório, Villevie, e de uma resina composta, Tetric Ceram, associada a dois tipos de sistema adesivos, XENO III e Single Bond. Quarenta incisivos inferiores unirradiculares foram distribuídos em três grupos de dez dentes cada e cinco dentes para cada grupo controle, positivo e negativo. Os espécimes, após a cirurgia de acesso, foram preparados por meio de sistema de instrumentação rotatória e irrigados com água destilada e deionizada. A porção externa dos dentes foi impermeabilizada até 2 mm aquém da margem externa da cirurgia de acesso. Colocou-se no interior do canal radicular um cone de papel seguido de uma pensa de algodão impregnados com solução alcoólica de dimetilglioxima 1%. A cavidade endodôntica foi selada de acordo com os seguintes grupos: GA- sistema adesivo autocondicionante XENO III + resina composta; GB- sistema adesivo Single Bond + resina composta; e GC- selador provisório. Os espécimes foram imersos em recipientes contendo solução de sulfato de níquel 5% e submetidos à ciclagem térmica por 72h. Os testes de Kruskal-Wallis e Dunn foram utilizados para análise dos resultados com nível de 5% de signifcância. O menor nível de microinfltração foi observado no grupo do restaurador provisório (GC), com diferença estatística signifcante em relação aos demais grupos (P<0,001). Os grupos A e B mostraram-se semelhantes ao controle positivo (P>0,05), com os maiores índices de microinfltração. Concluiu-se que nenhum dos materiais avaliados foi capaz de impedir a microinfltração coronária.

The purpose of this study was to evaluate the sealing capacity of a temporary restorative material (Villevie) and a composite resin, Tetric Ceram, associated with two adhesive systems (XENO III and Single Bond). Forty single-rooted mandibular incisors were distributed into three experimental groups of 10 teeth each, and two control groups (positive and negative) of 5 teeth each. After preparation of the access cavities, the canals were instrumented with a rotary system and irrigated with distilled deionized water. The external surfaces of the teeth were rendered water-proof up to 2 mm from the external margins of the access cavities. A paper point and a coton mesh impregnated with an alcoholic 1% dimethylglyoxime were placed inside the root canals, and the endodontic access cavities were sealed according to the following groups: GA- XENO III self-etch adhesive system + composite resin; GB- Single Bond etch-and-rinse adhesive system + composite resin; and GC- temporary restorative material. The specimens were immersed in receptacles containing a 5% nickel sulfate solution and subjected to a thermal cycling regimen during 72 h. The Kruskal-Wallis and Dunn's tests were used for statistical analysis of the results at 5% signifcance level. The group restored with the temporary restorative material (GC) presented statistically signifcant less coronal leakage than the other groups (p<0.001). GA and GB were statistically similar to the positive control (p>0.05), showing the highest levels of coronal leakage. None of the tested materials was able to prevent the occurrence of coronal leakage.

Ex vivo evaluation of coronal and apical microbial leakage of root canal - Filled with gutta-percha or Resilon/Epiphany root canal filling material.

Objective: This ex vivo study compared coronal and apical microleakage of root canals filled with Resilon/Epiphany (RE) or gutta-percha/Grossman sealer (GP), using either lateral condensation (LC) or System B (SB) technique. Materials and Methods: Specimens in eight experimental groups were obturated using the following materials and techniques: Groups 1 and 3 - GP and LC; groups 2 and 4 - GP and SB; groups 5 and 7 - RE and LC; groups 6 and 8 - RE and SB. Apical and coronal leakages were tested using bacterial methods. For coronal analysis, the number of days required for complete contamination of the root canals was recorded according to observation of the brain heart infusion broth turbidity for 15 weeks. For apical analysis, the teeth were cleaved and the leakage was measured at 30 days. Data were collected for each sample and analyzed statistically with the Chi-square and ANOVA tests. Results: Leakage was found in all groups. The difference between filling materials, obturation techniques, and median time of leakage was not statistically significant for coronal ( P=0.847) and apical ( P=0.5789) leakages. Conclusion: There were no differences between the different filling materials (gutta-percha/Grossman sealer and Resilon/Epiphany) and obturation techniques (lateral condensation and system B technique) in coronal or apical leakages.

Coronal leakage of four intracanal medications after exposure to human saliva in the presence of a temporary filling material.

Aim: To determine the time required for the recontamination of root canals medicated with four different materials. Materials and Methods: A total of 60 intact, caries-free, human single-rooted teeth with straight roots were selected for this study. After chemo-mechanical preparation they must be changed in the specimens into seven groups: 10 teeth medicated with calcium hydroxide (Ca(OH) 2) + Camphorated paramonochlorophanol (CPMC) (G.1); 10 medicated with 2.5% Sodium hypochlorite (NaOCL) (G.2); 10 medicated with 2% Chlorhexidine gluconate (CHX) in gel (G.3); 10 medicated with 2% CHX in gel + Ca(OH) 2 (G.4); 10 without intracanal medicament and sealed with a coronal temporary filling (G.5). Five teeth were without intracanal medicament and coronally unsealed, used as the positive control group (PC) (G.6) and 5 teeth with intact crowns used as the negative control group (NC) (G.7). Glass vials with rubber stoppers were adjusted for use. The medicaments were prepared and injected into the root canals using sterile plastic syringes. An apparatus was used to evaluate for 30 days leakage. The chamber was filled with 3 ml of human saliva and Brain Heart Infusion (BHI) broth, incubated at 37°C and checked daily for the appearance of turbidity in the BHI broth. Results: Recontamination was detected after an average time of 2.6 days in group 2, 15.9 days in group 3, 30 days in group 1, 27.6 days in group 4, 2.9 days in group 5, 1 day in the positive control, and there was no contamination in the negative control group. Conclusion : The NaOCl group showed the highest worst average of recontamination; on the other hand, high averages were also shown by Ca(OH) 2 + CPMC and Ca(OH) 2 + 2% CHX in gel.

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment: study in dogs

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35 percent of microbial leakage in the groups without plugs and 15 percent of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

O propósito deste trabalho foi avaliar a influência da infiltração coronária no reparo dos tecidos periapicais após obturação dos canais radiculares, preparo para pino e proteção ou não de um "plug" de cimento temporário. Quarenta canais de dentes de cães foram instrumentados e obturados pela técnica da condensação lateral ativa com cones de guta-percha e os cimentos Endomethasone e CRCS. Após preparo para pino os remanescentes do material obturador foram protegidos ou não com um "plug" do cimento temporário Coltosol e expostos ao meio oral por 90 dias. Decorrido este período, os animais foram mortos e os espécimes foram removidos e preparados para análises histomorfológica e histobacteriológica. Foi observado 35 por cento de casos de infiltração bacteriana nos grupos sem "plug" e 15 por cento nos grupos com "plug". Concluiu-se estatisticamente que o "plug" de Coltosol foi eficiente no controle da infiltração coronária de microorganismos (p=0,05), e que os cimentos CRCS e Endomethasone apresentaram resultados semelhantes (p>0,05).

Bacteriologic in vitro coronal leakage study of before and after post space preparation / 대한치과보존학회지

The purpose of present study was to compare the speed of coronal leakage before and after post space preparation using Streptococcus mutans. Forty straight extracted human teeth were selected. The crowns were removed to a uniform remaining root length 14 mm. Canals were enlarged by 06 taper Profiles(R) to a size #40 as a master apical file. And these were filled with gutta percha point and Tubuliseal(R) sealer, using continuous wave technique. Groupings are as follows. Group 1 - These teeth were obturated without sealer. Group 2 - These teeth were obturated and covered the surface of the root completely with sticky wax. Group 3 - These teeth were obturated. Group 4 - These teeth were obturated and prepared for post space remaining 5 mm of gutta percha. The teeth were suspended in plastic tubes. The upper chamber received the bacterial suspension everyday to simulate clinical situation. The lower chamber consisted of BHI added Andrade's indicator. All roots in the positive control group (Group 1) turned yellow within 24 h and those of negative control group (Group 2) remained red throughout the experimental period (70 days). The samples of group 3 were contaminated within an average of 27.2 days. The samples of group 4 were contaminated within an average of 15.7 days, ranging from 9 to 22 days. There was significant difference between group 3 and group 4 statistically (p < 0.05).

The effect of the endodontic access cavity on the marginal leakage of crowns / 대한치과보존학회지

The marginal integrity of the crown can be broken during endodontic access cavity preparation due to the vibration of burs. Therefore, the purpose of this study was to evaluate the effect of endodontic access cavity preparation on the marginal leakage of full veneer gold crowns. 24 intact molars were mounted in acrylic resin blocks and prepared for crowns by a restorative dentist and crowns were cast with gold alloy. 20 Crowns were cemented with glass ionomer cement and 2 crowns were not cemented for positive control. 200 thermo-cycles from 5degrees C to 50degrees C with a travel time of 20s were completed. Then samples were randomly divided into 2 experimental groups of 9 each. Endodontic access preparation and zinc-oxide eugenol temporary fillings were done in Group 1. Teeth in Group 2 were not treated. Samples were coated with 2 layers of nail varnish and were immersed in 1% methylene blue dye for 20 hrs. Endodontic access was prepared in 2 samples, which were coated with nail varnish on all surfaces for negative control. After washing in running water, gold crowns were cut with a #330 bur. Four buccolingual sections, 2 mm apart, were cut from the central section of each tooth and were examined and scored under the microscope for dye leakage. Score 1: leakage to the cervical 1/3 of the axial wall, Score 2: leakage to the middle 1/3 of the axial wall, Score 3: leakage to the coronal 1/3 of the axial wall, Score 4: leakage to the occlusal surface. The median value for Group 1 is 4 and for Group 2 is 2. The result of this study showed that samples in Group 1 leaked more than those in Group 2. This finding was significant(P<0.001).