Radiographic analysis the obturation's quality in root canal treatment performed by a South Brazilian sample of undergraduate students / Análise radiográfica da obturação em tratamentos endodônticos realizados por alunos de Odontologia de uma amostra do sul do Brasil

ABSTRACT Objective to investigate the quality of root canal treatments performed by undergraduate students. Methods 274 root-filled teeth (excluding molars) from the Department of Endodontology of the Federal University of Santa Catarina in a nine-year period were selected and evaluated by two calibrated examiners. The evaluation was based on tooth type, number of root canals, presence or absence curvature, length of filling material considered the radiographic apex as reference (considered adequate shorter than 2mm from radiographic apex), filling material density, filling taper, and overall quality of RCT. Chi-square and Fisher exact tests were performed to analyze associations between variables of interest (p<0.05). Results 197 RCT were classified as acceptable (71.9%). The frequency of adequate RCT was significantly higher in incisor (79.4%) than in premolars (66.4%) or canines (58.1%) (p=0.015). The number of canals did not influence root canal quality in this sample (p>0.05). The factor more frequently identified as unacceptable was filling length (26.6%). All RCT performed in curved teeth and classified as unacceptable were underfilled. Procedural errors, such as perforations or instrumental separation, were not found in this sample. Conclusion The most common criteria identified as unacceptable was the length of the filling material. Incisors had better quality assessment rates than canines and premolars. The high-quality rates found in this sample may be linked to the professor/student rates.

RESUMO Objetivo Investigar a qualidade dos tratamentos endodônticos realizados por alunos de graduação em odontologia. Métodos 274 dentes (excluindo molares) com endodontia realizada no Departamento de Endodontia da Universidade Federal de Santa Cataria durante 9 anos foram avaliados por dois examinadores calibrados. A avaliação foi baseada no tipo de dente, número de condutos radiculares, presença ou ausência de curvatura, nível da obturação em relação ao ápice radiográfico (considerado adequado quando a menos de 2mm do ápice radiográfico), densidade do material obturador, espessura da obturação e qualidade geral do tratamento. Teste qui quadrado e exato de Fisher foram usados para avaliar a associação entre as variáveis de interesse (p<0.05). Resultados 197 tratamentos foram considerados adequados (71.9%). A frequência de tratamentos adequado foi maior em incisivos (79.4%), do que em pré-molares (66.4%) e caninos (58.1%) (p=0.015). O número de canais não influenciou a qualidade do tratamento nessa amostra (p>0.05). O fator mais associado a tratamentos com qualidade inadequada foi o nível da obturação (26.6%). Todos os tratamentos inadequados, em dentes com curvatura, estavam com obturação mais do que 2mm aquém do ápice. Não houveram erros, como perfuração ou separação de instrumentais. Conclusão O critério mais frequentemente identificado como inadequado foi o nível apical da obturação. Tratamentos realizados em incisivos resultaram em qualidade superior aos em caninos e pré-molares. A alta qualidade dos tratamentos dessa amostra pode estar relacionada com a razão estudante/professor.

Alternative to Avoid Tooth Discoloration after Regenerative Endodontic Procedure: A Systematic Review.

This systematic review aimed to evaluate whether alternative materials to conventional triple antibiotic paste (TAP - metronidazole, ciprofloxacin, and minocycline) and grey mineral trioxide aggregate (GMTA) could avoid tooth discoloration in teeth submitted to Regenerative Endodontic Procedure (REP). It was also investigated if dental bleaching is able to reverse the color of darkened teeth due to REP. The search was conducted in four databases (Medline via PubMed, Scopus, ISI Web of Science and BVS - Virtual health library), following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The retrieved papers were uploaded in the software EndNoteTM and two reviewers independently selected the studies and extracted the data. Only studies in humans (case reports, case series, clinical trials) were included in the review. From 1,122 potentially eligible studies, 83 were selected for full-text analysis, and 38 were included in the review. The included studies were mainly case reports (76.3 %). The studies described a total of 189 teeth submitted to REP. From these, about 54% of teeth presented some degree of discoloration. Most teeth presenting color alteration were treated with TAP, especially when combined with GMTA. Only three studies performed dental bleaching to restore the color of teeth and neither bleaching technique was able to restore the original color of the crowns. The use of alternative materials to TAP and GMTA, such as double antibiotic paste or Ca(OH)2 pastes and white mineral trioxide aggregate or BiodentineTM, reduces the occurrence of tooth discoloration.

Alternative to avoid tooth discoloration after regenerative endodontic procedure: a systematic review

Abstract This systematic review aimed to evaluate whether alternative materials to conventional triple antibiotic paste (TAP - metronidazole, ciprofloxacin, and minocycline) and grey mineral trioxide aggregate (GMTA) could avoid tooth discoloration in teeth submitted to Regenerative Endodontic Procedure (REP). It was also investigated if dental bleaching is able to reverse the color of darkened teeth due to REP. The search was conducted in four databases (Medline via PubMed, Scopus, ISI Web of Science and BVS - Virtual health library), following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The retrieved papers were uploaded in the software EndNoteTM and two reviewers independently selected the studies and extracted the data. Only studies in humans (case reports, case series, clinical trials) were included in the review. From 1,122 potentially eligible studies, 83 were selected for full-text analysis, and 38 were included in the review. The included studies were mainly case reports (76.3 %). The studies described a total of 189 teeth submitted to REP. From these, about 54% of teeth presented some degree of discoloration. Most teeth presenting color alteration were treated with TAP, especially when combined with GMTA. Only three studies performed dental bleaching to restore the color of teeth and neither bleaching technique was able to restore the original color of the crowns. The use of alternative materials to TAP and GMTA, such as double antibiotic paste or Ca(OH)2 pastes and white mineral trioxide aggregate or BiodentineTM, reduces the occurrence of tooth discoloration.

Resumo Esta revisão sistemática teve como objetivo avaliar se materiais alternativos à pasta tri-antibiótica convencional (TAP, em Inglês - metronidazol, ciprofloxacina e minociclina) e ao agregado trióxido mineral cinza (MTA cinza) poderiam evitar a descoloração dentária em dentes submetidos ao procedimento endodôntico regenerativo (REP, em Inglês). Também foi investigado se o clareamento dental é capaz de reverter a cor dos dentes escurecidos devido ao REP. A busca foi realizada em quatro bases de dados (Medline via PubMed, Scopus, ISI Web of Science e BVS - Biblioteca Virtual de Saúde), seguindo os Principais Itens para Relatar Revisões Sistemáticas e Meta-análises. Os artigos obtidos foram carregados no software EndNoteTMe dois revisores independentes selecionaram os estudos e extraíram os dados. Apenas estudos em humanos (relatos de casos, séries de casos, ensaios clínicos) foram incluídos na revisão. De 1.122 estudos potencialmente elegíveis, 83 foram selecionados para análise do artigo completo, e 38 foram incluídos na revisão. Os estudos incluídos foram principalmente relatos de casos (76,3%). Os estudos descreveram um total de 189 dentes submetidos ao REP. Destes, cerca de 54% dos dentes apresentaram algum grau de descoloração. A maioria dos dentes com alteração de cor foi tratada com TAP, principalmente quando combinada com MTA-cinza. Apenas três estudos realizaram o clareamento dental para restaurar a cor dos dentes e nem a técnica de clareamento conseguiu restaurar a cor original das coroas. O uso de materiais alternativos à TAP e ao MTA cinza, como a pasta bi-antibiótica, pasta de Ca(OH)2e MTA branco ou BiodentineTM, reduz a ocorrência de descoloração dentária.

Effect of Milk Renewal on Cell Viability In Vitro at Different Time Frames.

The purpose of this study was to evaluate if the renewal of milk as a storage medium, every 12, 24 and 48 h, is able to increase its ability to maintain human periodontal ligament fibroblasts (PDLF) viability over time. PDLF were soaked in Minimum Essential Medium at 37 °C (MEM-37) (positive control), tap water (Water) (negative control) and in skimmed milk (44 wells) at 5 °C and 20 °C. The skimmed milk was renewed every 12 h (Milk-12), 24 h (Milk-24) and 48 h (Milk-48) in 11 wells of each plate, and the milk in the remaining 11 wells of each plate was maintained in situ (not renewed milk) (NRM). After 24, 48, 72, 96 and 120 h, cell viability was determined by the tetrazolium salt-based colorimetric (MTT) assay. Data were statistically analyzed by Kruskal-Wallis, Scheffé and Mann-Whitney tests (a=5%). At 5 °C, only Milk-48 was significantly better than NRM. At 20 °C, NRM was more effective than Milk-12 and Milk-24 in all time periods. In relation to the temperature (5 °C or 20 °C), renewal of milk at 5 °C was better in maintaining cell viability than the renewal at 20 °C. In conclusion, the renewal of milk was able to increase its ability to maintain cell viability only when performed every 48 h in milk maintained at 5 °C.

Effect of Milk Renewal on Cell Viability In Vitro at Different Time Frames

Abstract The purpose of this study was to evaluate if the renewal of milk as a storage medium, every 12, 24 and 48 h, is able to increase its ability to maintain human periodontal ligament fibroblasts (PDLF) viability over time. PDLF were soaked in Minimum Essential Medium at 37 °C (MEM-37) (positive control), tap water (Water) (negative control) and in skimmed milk (44 wells) at 5 °C and 20 °C. The skimmed milk was renewed every 12 h (Milk-12), 24 h (Milk-24) and 48 h (Milk-48) in 11 wells of each plate, and the milk in the remaining 11 wells of each plate was maintained in situ (not renewed milk) (NRM). After 24, 48, 72, 96 and 120 h, cell viability was determined by the tetrazolium salt-based colorimetric (MTT) assay. Data were statistically analyzed by Kruskal-Wallis, Scheffé and Mann-Whitney tests (a=5%). At 5 °C, only Milk-48 was significantly better than NRM. At 20 °C, NRM was more effective than Milk-12 and Milk-24 in all time periods. In relation to the temperature (5 °C or 20 °C), renewal of milk at 5 °C was better in maintaining cell viability than the renewal at 20 °C. In conclusion, the renewal of milk was able to increase its ability to maintain cell viability only when performed every 48 h in milk maintained at 5 °C.

Resumo O objetivo deste estudo foi avaliar se a renovação do leite, a cada 12, 24 e 48 h, é capaz de aumentar sua capacidade de manter a viabilidade de fibroblastos do ligamento periodontal humano (FLPH) ao longo do tempo. FLPH foram conservados em Meio Essencial Mínimo a 37 °C (MEM-37) (controle positivo), água da torneira (água) (controle negativo) e em leite desnatado (44 poços) a 5 °C e 20 °C. O leite desnatado foi renovado a cada 12 h (leite-12), 24 h (leite-24) e 48 h (leite-48) em 11 poços de cada placa, e em outros 11 poços de cada placa o leite foi deixado in situ (leite não renovado) (LNR). Depois de 24, 48, 72, 96 e 120 h, a viabilidade celular foi determinada pelo ensaio colorimétrico à base de sal tetrazólio (MTT). Os dados foram analisados estatisticamente pelos testes de Kruskal-Wallis, Scheffé e Mann-Whitney (α=5%). A 5 °C, somente o leite-48 foi significantemente melhor do que o LNR. A 20 °C, LNR foi mais efetivo do que o leite-12 e leite-24 em todos os períodos de tempo. Em relação à temperatura (5 °C ou 20 °C), a renovação do leite a 5 °C foi melhor na manutenção da viabilidade celular do que a renovação a 20 °C. Concluindo, a renovação do leite foi capaz de aumentar sua habilidade em manter a viabilidade celular apenas quando realizada a cada 48 h no leite mantido a 5 °C.

Crown discoloration promoted by materials used in regenerative endodontic procedures and effect of dental bleaching: spectrophotometric analysis.

OBJECTIVES: To assess tooth crown's color after intracanal treatment with triple antibiotic paste (TAP) or calcium hydroxide (CH); cervical sealing with glass ionomer cement (GIC) or mineral trioxide aggregate (MTA); and bleaching with carbamide peroxide. MATERIAL AND METHODS: After pulp removal and color spectrophotometer measurement, 50 bovine incisors were divided into 4 experimental groups and one control (untreated). Experiments were performed in phases (Ph). Ph1: TAP (ciprofloxacin, metronidazole, minocycline), TAPM (ciprofloxacin, metronidazole, amoxicillin), DAP (ciprofloxacin, metronidazole), or CH treatment groups. After 1 and 3 days (d); 1, 2, 3 weeks (w); and 1, 2, 3 and 4 months (m), color was measured and medications were removed. Ph2: GIC or MTA cervical sealing, each using half of the specimens from each group. Color was assessed after 1d, 3d; 1w, 2w, 3w; 1m and 2m. Ph3: Two bleaching sessions, each followed by color measurement. Data were analyzed with ANOVA and post-hoc Holm-Sidak method. RESULTS: Ph1: Specimens of TAP group presented higher color alteration (ΔE) mean than those of TAPM group. No significant difference was found among TAP or TAPM and CH, DAP or Control groups. Ph2: cervical sealing materials showed no influence on color alteration. Ph3: Different ΔE means (from different groups), prior to bleaching, became equivalent after one bleaching session. CONCLUSIONS: TAP induces higher color alteration than TAPM; color alteration increases over time; cervical sealing material has no influence on color alteration; and, dental bleaching was able to recover, at least partially, the tooth crown's color.

Crown discoloration promoted by materials used in regenerative endodontic procedures and effect of dental bleaching: spectrophotometric analysis

Abstract Regenerative endodontic procedure (REP) has been proposed as a new approach to treat immature permanent teeth. However, materials used in REP for root canal disinfection or cervical sealing may induce tooth discoloration. Objectives To assess tooth crown’s color after intracanal treatment with triple antibiotic paste (TAP) or calcium hydroxide (CH); cervical sealing with glass ionomer cement (GIC) or mineral trioxide aggregate (MTA); and bleaching with carbamide peroxide. Material and Methods After pulp removal and color spectrophotometer measurement, 50 bovine incisors were divided into 4 experimental groups and one control (untreated). Experiments were performed in phases (Ph). Ph1: TAP (ciprofloxacin, metronidazole, minocycline), TAPM (ciprofloxacin, metronidazole, amoxicillin), DAP (ciprofloxacin, metronidazole), or CH treatment groups. After 1 and 3 days (d); 1, 2, 3 weeks (w); and 1, 2, 3 and 4 months (m), color was measured and medications were removed. Ph2: GIC or MTA cervical sealing, each using half of the specimens from each group. Color was assessed after 1d, 3d; 1w, 2w, 3w; 1m and 2m. Ph3: Two bleaching sessions, each followed by color measurement. Data were analyzed with ANOVA and post-hoc Holm-Sidak method. Results Ph1: Specimens of TAP group presented higher color alteration (ΔE) mean than those of TAPM group. No significant difference was found among TAP or TAPM and CH, DAP or Control groups. Ph2: cervical sealing materials showed no influence on color alteration. Ph3: Different ΔE means (from different groups), prior to bleaching, became equivalent after one bleaching session. Conclusions TAP induces higher color alteration than TAPM; color alteration increases over time; cervical sealing material has no influence on color alteration; and, dental bleaching was able to recover, at least partially, the tooth crown’s color.

Effect of temperature and seven storage media on human periodontal ligament fibroblast viability.

BACKGROUND/AIM: Natural resources, such as coconut water, propolis, and egg whites, have been examined as possible storage media for avulsed teeth. However, there is a lack of research focused on the efficacy of these three products together compared with Hank's balanced salt solution and milk. The aim of this study was to evaluate the capacity of seven storage media to maintain the viability of human periodontal ligament fibroblasts (PDLFs). MATERIAL AND METHODS: PDLFs were kept at 5°C and 20°C, in skimmed milk (SMilk), whole milk (WMilk), recently prepared Hank's balanced salt solution (HBSS), Save-A-Tooth® system's HBSS (Save), natural coconut water (Coconut), Propolis, and egg white (Egg) for 3, 6, 24, 48, 72, 96, and 120 h, through the analysis of tetrazolium salt-based colorimetric (MTT) assay. RESULTS: At 5°C, SMilk and WMilk were better than HBSS in maintaining cell viability, from 24 h onward. At 20°C, HBSS was the best storage medium at 96 and 120 h. At both temperatures, from 6 h onward, Coconut, Propolis and Egg were less effective than SMilk, WMilk, and HBSS. In general, the performance of Coconut, Propolis and Egg were not influenced by storage temperature. However, the lowest temperature undermined the effectiveness of HBSS from 24 h and favored SMilk and WMilk, from 96 and 48 h onward, respectively. Save and water were the worst storage media. CONCLUSION: SMilk was the best storage medium, followed by WMilk and HBSS. Coconut, Propolis, and Egg can be indicated for the conservation of PDLF up to 3 h. The lower temperature (5°C) undermined the effectiveness of HBSS and favored SMilk and WMilk.

Avaliação radiográfica e em microscopica eletrônica de varredura de remanescentes de obturação após a re-instrumentação endodôntica / Radiographic and scanning electron microscopic assessment of root canal filling remnants after endodontic re-instrumentation

Objetivo: Falhas no tratamento endodôntico podem ocorrer por várias razões. O retratamento endodôntico é uma alternativa interessante para tratar esse problema clínico. No entanto, não é possível remover completamente o material obturador do canal radicular por qualquer das técnicas atuais de retratamento. O objetivo deste estudo foi avaliar a presença de resíduos de material obturador após a re-instrumentação endodôntica. Material e Métodos: Sessenta dentes anteriores humanos foram preparados pela técnica escalonada com Flexofiles, limas K e brocas GatesGlidden (GG). Entre o uso de cada instrumento ou broca, os canais radiculares foram irrigados com hipoclorito de sódio (NaOCl). A lama dentinária foi removida por irrigação com ácido etilenodiaminotetraacético e NaOCl. Após secagem com pontas de papel, os canais radiculares foram divididos aleatoriamente em 5 grupos (n = 12), de acordo com o material obturador: cones Resilon/cimento Real Seal ou cones de guta-percha e cimento Endofill, Sealapex, AH Plus ou MTA Fillapex. Após uma semana, o material obturador foi removido usando Eucaliptol e K-files. Os canais radiculares foram re-instrumentados com limas K e brocas GG de tamanhos maiores do que as anteriormente usadas. A presença de remanescente de material obturador no canal radicular foi analisada por radiografia e microscopia eletrônica de varredura (MEV). A análise estatística foi realizada pelo teste de Regressão Logística Binária (P < 0,05). Resultados: As análises radiográfica e por MEV mostraram que o material do grupo MTA Fillapex foi melhor removido do que o dos grupos Endofill, Sealapex, AH Plus e Real Seal. Conclusão: Após a re-instrumentação, o grupo MTA Fillapex apresentou menos remanescentes nos canais radiculares que os grupos Endofill, Sealapex, AH Plus e Real Seal. O material residual foi encontrado mais frequentemente no terço apical. (AU)

Objective: Failures in endodontic treatment may occur by several reasons. Endodontic retreatment is an interesting alternative to manage this clinical problem. However, it is not possible to completely remove the root canal filling by any current retreatment technique. The aim of this study was to evaluate the presence of residual root canal filling materials after endodontic reinstrumentation. Material and Methods: Sixty extracted anterior human teeth were prepared by step-back technique with Flexofiles, K-files and Gates-Glidden (GG) burs. Between the use of each file or bur, root canals were irrigated with sodium hypochlorite (NaOCl). Smear layer was removed by irrigation with ethylenediaminetetraacetic acid and NaOCl. After drying with paper points the root canals were randomly divided into 5 groups (n = 12), according to filling material: Resilon cones/Real Seal sealer or gutta-percha cones and Endofill, Sealapex, AH Plus or MTA Fillapex sealers. After one week, root canal fillings were removed using Eucaliptol and K-files. Root canals were reinstrumented with K-files and GG burs sized larger than the first ones. The removal of root canal filling material was analyzed by radiography and scanning electron microscopy (SEM). Statistical analysis was performed using Binary Logistic Regression test (P < 0.05). Results: Radiographic and SEM analysis showed that material from the MTA Fillapex group was better removed than that from Endofill, Sealapex, AH Plus and Real Seal groups. Conclusion: After re-instrumentation, MTA Fillapex group showed less remnants into the root canals than Endofill, Sealapex, AH Plus and Real Seal groups. Residual material was most often found in the apical third(AU)

Fibroblast Viability after Storage at 20 °C in Milk, Hank's Balanced Salt Solution and Coconut Water.

The objective of this study was to evaluate the effectiveness of various storage media at 20 °C in maintaining the viability of human periodontal ligament fibroblasts (HPLF) over time. HPLF were maintained at 20 °C in skim milk (SM), whole milk (WM), freshly prepared Hank's balanced salt solution (HBSS), Save-A-Tooth(r), natural coconut water (NCW), coconut water industrialized (ICW) and tap water (negative control) for 3, 6, 24, 48, 72, 96 and 120 h. Cells maintained in Minimal Essential Medium (MEM-37) at 37 °C served as a positive control. Cell viability was determined by MTT assay. Statistical analysis was performed by Kruskal-Wallis test and Scheffe test (α = 5%). From 24 h, NCW was significantly better in maintaining cell viability than all other tested storage media (p<0.05). SM and WM were significantly better than HBSS for up to 72 h. Save-A-Tooth(r) and ICW were the worst conservation storage media. In conclusion, the effectiveness of the tested storage media to maintain the viability of the periodontal ligament cells was as follows, in a descending order: NCW > MEM-37> SM and IM> HBSS> ICW > Save-A-Tooth(r)> tap water.

Tissue characterization following revascularization of immature dog teeth using different disinfection pastes.

Revascularization of immature teeth with necrotic pulps traditionally involves the use of triple antibiotic paste, which may sometimes lead to undesirable complications. The objective of this study was to assess tissue repair in immature dog teeth with apical periodontitis subjected to revascularization, comparing two different pastes used for root canal disinfection. Apical periodontitis was induced in 30 dog premolars. Teeth were randomly divided into three experimental groups: root canals filled with triple antibiotic paste (n = 10); root canals filled with 1% propolis paste (n = 10); and no medication (n = 10). An additional group (n = 10, no intervention) was used as control. After 7 months, the jaws were histologically evaluated for the following variables: newly formed mineralized tissue (present/absent); vital tissue in the canal space (absent/periodontal ligament-like/pulp-like); apical extension of root (present/absent); and severity of inflammatory process (absent/mild/moderate/severe). There were no statistically significant differences among the experimental groups in new mineralized tissue formation and apical root development. The formation of vital tissue in the canal space, in turn, was statistically different between the triple paste and propolis groups: vital tissues were present in all revascularized teeth disinfected with propolis paste (100%), compared to 71% of those disinfected with the triple paste. Severity of inflammatory process was different between the triple paste and no medication groups. The new tissues formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. Propolis may have some advantages over the triple paste for the revascularization of immature teeth.

Fibroblast Viability after Storage at 20 °C in Milk, Hank's Balanced Salt Solution and Coconut Water

Abstract The objective of this study was to evaluate the effectiveness of various storage media at 20 °C in maintaining the viability of human periodontal ligament fibroblasts (HPLF) over time. HPLF were maintained at 20 °C in skim milk (SM), whole milk (WM), freshly prepared Hank's balanced salt solution (HBSS), Save-A-Tooth(r), natural coconut water (NCW), coconut water industrialized (ICW) and tap water (negative control) for 3, 6, 24, 48, 72, 96 and 120 h. Cells maintained in Minimal Essential Medium (MEM-37) at 37 °C served as a positive control. Cell viability was determined by MTT assay. Statistical analysis was performed by Kruskal-Wallis test and Scheffe test (α = 5%). From 24 h, NCW was significantly better in maintaining cell viability than all other tested storage media (p<0.05). SM and WM were significantly better than HBSS for up to 72 h. Save-A-Tooth(r) and ICW were the worst conservation storage media. In conclusion, the effectiveness of the tested storage media to maintain the viability of the periodontal ligament cells was as follows, in a descending order: NCW > MEM-37> SM and IM> HBSS> ICW > Save-A-Tooth(r)> tap water.

Resumo O objetivo deste estudo foi avaliar a efetividade de vários meios de conservação a 20 °C em manter a viabilidade de fibroblastos do ligamento periodontal humano (FLPH) ao longo do tempo. FLPH foram conservados a 20 °C em leite desnatado (LD), leite integral (LI), solução salina balanceada de Hank (HBSS) recém preparada, Save-A-Tooth(r) (Save), água de coco natural (ACN), água de coco industrializada (ACI) e água de torneira (água - controle negativo) por 3, 6, 24, 48, 72, 96 e 120 h. Células conservadas em Meio Essencial Mínimo (MEM-37) a 37 °C serviram como controle-positivo. A viabilidade celular foi determinada pelo ensaio MTT. A análise estatística dos dados foi realizada pelos testes Kruskal-Wallis e Scheffé (α=5%). A partir de 24 h, ACN foi significantemente melhor em manter a viabilidade celular do que todos os outros meios testados (p<0,05). LD e LI foram significantemente melhores do que a HBSS por até 72 h. Save e ACI foram os piores meios de conservação. Concluindo, a efetividade dos meios de conservação testados em manter a viabilidade das células do ligamento periodontal foi a seguinte em ordem decrescente: ACN > MEM-37 > LD e LI > HBSS > ACI > Save > água.

Effect of passive ultrasonic irrigation on diffusion of hydroxyl ion through radicular dentine.

OBJECTIVE: This study investigated the effect of passive ultrasonic irrigation (PUI) on diffusion of hydroxyl ions through radicular dentine. MATERIALS AND METHODS: After chemomechanical preparation of root canals in 60 human teeth, the cementoenamel junction and the apical 3 mm of each root were covered with fast-setting adhesive. Four final irrigation protocols were applied (n = 10): group (G)1: irrigation with EDTA + NaOCl; G2: EDTA + PUI + NaOCl; G3: EDTA+(NaOCl + PUI); G4: (EDTA + PUI) + (NaOCl + PUI). Ten teeth irrigated with distilled water followed by PUI (G5) served as the negative control. After drying, the canals were filled with calcium hydroxide paste (CH), sealed and kept in individual vials containing 10 mL of distilled water with known pH values. At 7, 14, and 21 days, the pH of the water in the vials was measured. The pH values in various groups were analyzed with two-way ANOVA (irrigation protocol and time period as factors) and Holm-Sidak multiple comparison test (α = 0.05). RESULTS: Changes in pH was not significantly different among groups (P = 0.651) but was significant different among different time periods (P < 0.0001). For all groups, ion diffusion was higher at 14 and 21 days than at 7 days. CONCLUSIONS: PUI has no effect on diffusion of hydroxyl ions through radicular dentine. When CH is used as temporary filling material, a waiting period of at least 14 days is required to create an alkaline environment within the radicular dentine. CLINICAL RELEVANCE: The use of PUI during final irrigation phase does not improve the action of CH when it is used as temporary filling material.

Tissue characterization following revascularization of immature dog teeth using different disinfection pastes

Abstract Revascularization of immature teeth with necrotic pulps traditionally involves the use of triple antibiotic paste, which may sometimes lead to undesirable complications. The objective of this study was to assess tissue repair in immature dog teeth with apical periodontitis subjected to revascularization, comparing two different pastes used for root canal disinfection. Apical periodontitis was induced in 30 dog premolars. Teeth were randomly divided into three experimental groups: root canals filled with triple antibiotic paste (n = 10); root canals filled with 1% propolis paste (n = 10); and no medication (n = 10). An additional group (n = 10, no intervention) was used as control. After 7 months, the jaws were histologically evaluated for the following variables: newly formed mineralized tissue (present/absent); vital tissue in the canal space (absent/periodontal ligament-like/pulp-like); apical extension of root (present/absent); and severity of inflammatory process (absent/mild/moderate/severe). There were no statistically significant differences among the experimental groups in new mineralized tissue formation and apical root development. The formation of vital tissue in the canal space, in turn, was statistically different between the triple paste and propolis groups: vital tissues were present in all revascularized teeth disinfected with propolis paste (100%), compared to 71% of those disinfected with the triple paste. Severity of inflammatory process was different between the triple paste and no medication groups. The new tissues formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. Propolis may have some advantages over the triple paste for the revascularization of immature teeth.

Histologic Analysis of the Influence of a Gelatin-based Scaffold in the Repair of Immature Dog Teeth Subjected to Regenerative Endodontic Treatment.

INTRODUCTION: Regenerative endodontic treatment is a new and promising approach to manage immature teeth with necrotic pulps and apical periodontitis. The use of scaffolds is essential to treatment success, but many materials are difficult to acquire and have a high cost. This study assessed tissue repair in immature dog teeth with necrotic pulps and apical periodontitis after using a gelatin-based scaffold (Gelfoam; Pharmacia & Upjohn Co, Kalamazoo, MI). METHODS: Apical periodontitis was induced in 20 immature dog teeth. After disinfection with triple antibiotic paste for 2 weeks, canals were irrigated, dried, and filled with a blood clot alone (10 teeth) or combined with Gelfoam (10 teeth). Another 10 teeth were used as negative controls (no intervention). After 7 months, the dogs were euthanized. Histologic sections were stained with hematoxylin-eosin and analyzed in relation to tissue repair. Categoric data were analyzed using the Fisher exact test (P < .05), numeric data (histomorphometric analysis), and the Mann-Whitney U test. RESULTS: Histologic analysis revealed a higher percentage of roots with new cementumlike mineralized tissue and connective tissue inside the canal in the blood clot + Gelfoam group (P < .001). Histomorphometric analysis showed a higher area of mineralized tissue in the same group (P = .029). Apical extension of root and inflammation were similar between the experimental groups. The new tissue formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. CONCLUSIONS: The use of a gelatin-based scaffold (Gelfoam) combined with a blood clot improved repair in immature dog teeth with apical periodontitis subjected to regenerative endodontic treatment.

Influence of phosphate buffered saline on the bond strength of endodontic cement to dentin

Aim: To analyze the influence of exposure and time of exposure to phosphate buffered saline (PBS) on the push-out bond strength (BS) of Biodentine to dentine. Methods: Eighty 2-mm-thick dentin discs were obtained from transversal sections of human teeth roots. The space of the canal was enlarged using #2-#5 Gates-Glidden burs to obtain 1.3-mm-diameter standardized cavities. The discs were immersed in 17% EDTA followed by 1% NaOCl and dried. The spaces of the canals were filled with Biodentine and the samples were divided into 2 groups (n=40) according to the storage: G1: exposure to moistened cotton pellet; G2: exposure to PBS. After 30 min, 1, 3 and 28 days, 10 samples of each group were subjected to the push-out test. Data were analyzed using ANOVA and Tukey test (p < 0.05). Results: The specimens exposed to PBS had lower BS (p < 0.05), except for the 1-day period (p = 0.6017). In specimens of Group 1 the BS increased up to 3 days (p < 0.05). In specimens in Group 2, the BS increased from 30 min to 1 day (p < 0.0001) and remained stable up to 3 days (p = 0.9876). At 28 days, a significant decrease was observed in the BS values of both groups (p < 0.05). Conclusions: The exposure of Biodentine to PBS led to lower BS values. In general, the BS increased gradually up to 3 days and reduced at 28 days.

Adhesive interface and bond strength of endodontic sealers to root canal dentine after immersion in phosphate-buffered saline.

This study evaluated the bond strength (BS) and the adhesive interface of four endodontic sealers to root canal dentine, before, and after immersion in phosphate buffered saline (PBS) to simulate an in vivo environment. Eighty roots were instrumented using ProTaper rotatory files, under irrigation with 17% EDTA and 1% NaOCl. Posteriorly were divided into four groups (n = 20) according to the sealer used: Endofill, AH Plus, Sealapex, and MTA Fillapex. Each group was divided into two subgroups (n = 10) and stored at 37°C immersed in water for 7 days and in PBS for 60 days. From each subgroup, 1 mm thick sections were obtained. One section of each region (coronal, middle, and apical) was submitted to the push-out test and failures were observed. Twelve sections of each subgroup (four from each region) were evaluated under SEM. Three-way ANOVA evaluation for BS showed significant differences between groups and regions (P < 0.0001), but not between subgroups (P > 0.05). AH Plus had significantly higher BS than the others sealers, regardless of the analyzed subgroup (Tukey's test, P < 0.5). The most common failures were adhesive to dentine and cohesive of the sealer. The SEM evaluation (Kruskal-Wallis, Mann-Whitney) showed homogeneous adhesive interface formed and sealer tags in all groups with significant statistical differences with AH Plus, regardless of PBS immersion. AH Plus was superior to the other sealers for both BS and quality of interface formation. Immersion in PBS did not interfere on BS or adhesive interface of the sealers tested.

The sealing ability of MTA apical plugs exposed to a phosphate-buffered saline.

OBJECTIVE: The aim of this study was to evaluate the influence of exposure of the mineral trioxide aggregate (MTA) - with and without calcium chloride (CaCl2) - to phosphate-buffered saline (PBS) on the apical microleakage using a glucose leakage system. MATERIAL AND METHODS: Sixty root segments were randomly divided into 4 experimental groups (n=15). After resecting the apical segments and enlarging the canals with Gates-Glidden drills, the apical cavities were filled with MTA with or without CaCl2 and the root canals were dressed with a moistened cotton pellet or PBS, as follows: 1) MTA/cotton pellet; 2) MTA/PBS; 3) MTA+10%CaCl2/cotton pellet; 4) MTA+10%CaCl2/PBS. All root segments were introduced in floral foams moistened with PBS. After 2 months, all root segments were prepared to evaluate the glucose leakage along the apical plugs. The amount of glucose leakage was measured following an enzymatic reaction and quantified by a spectrophotometer. Four roots were used as controls. The data were analyzed using Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: There were no differences between groups 1 and 2 (p>0.05), and 3 and 4 (p>0.05). The addition of CaCl2 to the MTA significantly decreased its sealing ability (p<0.05). CONCLUSION: The interaction with PBS did not improve the MTA sealing ability. The addition of CaCl2 to the MTA negatively influenced the apical seal.

The sealing ability of MTA apical plugs exposed to a phosphate-buffered saline

OBJECTIVE: The aim of this study was to evaluate the influence of exposure of the mineral trioxide aggregate (MTA) - with and without calcium chloride (CaCl2) - to phosphate-buffered saline (PBS) on the apical microleakage using a glucose leakage system. MATERIAL AND METHODS: Sixty root segments were randomly divided into 4 experimental groups (n=15). After resecting the apical segments and enlarging the canals with Gates-Glidden drills, the apical cavities were filled with MTA with or without CaCl2 and the root canals were dressed with a moistened cotton pellet or PBS, as follows: 1) MTA/cotton pellet; 2) MTA/PBS; 3) MTA+10%CaCl2/cotton pellet; 4) MTA+10%CaCl2/PBS. All root segments were introduced in floral foams moistened with PBS. After 2 months, all root segments were prepared to evaluate the glucose leakage along the apical plugs. The amount of glucose leakage was measured following an enzymatic reaction and quantified by a spectrophotometer. Four roots were used as controls. The data were analyzed using Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: There were no differences between groups 1 and 2 (p>0.05), and 3 and 4 (p>0.05). The addition of CaCl2 to the MTA significantly decreased its sealing ability (p<0.05). CONCLUSION: The interaction with PBS did not improve the MTA sealing ability. The addition of CaCl2 to the MTA negatively influenced the apical seal. .

Mineral trioxide aggregate and Portland cement promote biomineralization in vivo.

INTRODUCTION: Mineral trioxide aggregate (MTA) and Portland cement have been shown to be bioactive because of their ability to produce biologically compatible carbonated apatite. This study analyzed the interaction of MTA and white Portland cement with dentin in vivo. METHODS: Seventy-two human dentin tubes were filled with MTA Branco, MTA BIO, and white Portland cement + 20% bismuth oxide (PC1) or PC1 + 10% of calcium chloride (PC2) and implanted subcutaneously in 18 rats at 4 sites from the dorsal area. Empty dentin tubes, implanted in rats of a pilot study, were used as control. After 30, 60, and 90 days, the animals were killed, and the dentin tubes were retrieved for scanning electron microscope analysis. RESULTS: In the periods of 30 and 60 days, the mineral deposition in the material-dentin interface (interfacial layer) and in the interior of dentinal tubules was detected in more tubes filled with MTA Branco and MTA BIO than in tubes filled with PC1 and PC2. After 90 days, the interfacial layer and intratubular mineralization were detected in all tubes except for 3 and 1 of the tubes filled with PC2, respectively. CONCLUSIONS: It was concluded that all the cements tested were bioactive. The cements released some of their components in the tissue capable of stimulating mineral deposition in the cement-dentin interface and in the interior of the dentinal tubules. MTA BIO and MTA Branco were more effective in promoting the biomineralization process than Portland cements, mainly after 30 and 60 days.