Scanning electron microscopy evaluation of dentin ultrastructure after surface demineralization.

CONTEXT: Knowledge about dentin microstructure is essential for execution of clinical procedures which require adhesion of materials to dentin. AIMS: To evaluate by scanning electron microscopy (SEM) the dentin ultrastructure after demineralization with 6 M and 12 M hydrochloric acid (HCl). SUBJECTS AND METHODS: Twenty dentin segments were immersed in fixative solution and dehydrated in ethanol. After 24 h, segments were randomly divided into 2 groups (n = 10), demineralized with 6 M HCl (G6M) and 12 M HCl (G12M), and prepared for SEM analysis. STATISTICAL ANALYSIS USED: Based on photomicrographs and chemical composition (energy dispersive X-ray spectroscopy) of dentin, a descriptive analysis was conducted. RESULTS: G6M samples revealed a demineralized surface with peritubular dentin exposure and small magnification of the dentinal tubules openings. The intertubular dentin was partially demineralized. Demineralization of G12M samples was more aggressive and at different depths, promoting erosion and "detachment" of dentin layers. Peritubular dentin was observed on the dentin surface. There was a large magnification of the dentinal tubules openings. In both groups, tubular structures showed a similar chemical composition to the intertubular dentin. Lamina limitans was not observed. CONCLUSIONS: Dentin demineralization is dependent on the HCl molarity and promotes exposure of peritubular dentin.

Correlation between Bond Strength to Dentin and Sealers Penetration by Push-Out Test and CLSM Analysis.

This study correlated the bond strength (BS) and dentin penetration of different sealers by push-out test and Confocal Laser Scanning Microscopy (CLSM) analysis. Forty-five root canals were prepared according to the crown-down technique and filled with gutta-percha associated to the following sealers (n=15): Endofill, AH Plus and MTA Fillapex. Five canals of each group were filled with the sealers added with 0.1% Rhodamine B dye. Next, the specimens were transversely sectioned and submitted to the push-out test (n=10) and CLSM analysis (n=5). The BS data showed the following means (MPa) and standard deviation: AH Plus (4.17±1.86); MTA Fillapex (3.13±1.96) and Endofill (2.10±1.03). Statistical analysis (two-way ANOVA, α=0.05) showed significant difference among sealers (p<0.001) and root canal thirds (p<0.001). The BS results of Endofill and MTA Fillapex were statistically similar (p>0.05), however, they were statistically different from AH Plus (p<0.001). The regional analysis of BS showed similarity between middle and apical thirds (p>0.05), and both were different from coronal portion (p<0.001). CLSM analysis verified tags formation in all groups and higher penetration of the specimens filled with AH Plus (p<0.05). The Kendall test (correlation between BS to dentin and sealer penetration into dentinal tubules) and the Pearson test (between failures pattern and sealer penetration into dentinal tubules) did not show correlation between the variables evaluated for all the tested sealers (p>0.05). AH Plus group had higher BS to dentin, and deeper tags formation than the other sealers. There was no significant correlation between BS and intratubular penetration of the tested sealers.

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.

Incidence of Root Resorption after the Replantation of Avulsed Teeth: A Meta-analysis.

INTRODUCTION: An avulsion injury is a serious trauma to pulp and periodontal tissues. After avulsion and replantation, teeth are at risk of infection and root resorption, which may affect treatment outcome and survival rate. Thus, the purpose of this systematic review was to evaluate the incidence of root resorption after the replantation of avulsed teeth. METHODS: Two reviewers searched 7 electronic databases for observational studies involving human subjects that evaluated the incidence of root resorption after tooth avulsion. Risk of bias (RoB) was evaluated using the Meta-Analysis of Statistics Assessment and Review Instrument, and the quality of available evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation tool. RESULTS: Of the 1507 articles, 23 met the inclusion criteria. A meta-analysis was conducted and showed that the incidence of internal root resorption was 1.2% (95% confidence interval [CI], 0.02-5.50). Regarding external root resorption, the incidence of surface root resorption was 13.3% (95% CI, 6.21-22.62), that of inflammatory root resorption was 23.2% (95% CI, 13.94-34.19), and that of replacement root resorption was 51.0% (95% CI, 40.10-62.00). Two studies presented a high RoB, 16 had a moderate RoB, and 11 had a low RoB. The overall level of evidence identified was very low. CONCLUSIONS: The incidence of root resorption after avulsion and replantation in descending order was replacement root resorption > inflammatory root resorption > surface root resorption > internal root resorption.

Effectiveness of nanoparticles solutions and conventional endodontic irrigants against Enterococcus faecalis biofilm.

CONTEXT: To overcome the challenge imposed by the presence of biofilm and reach significant bacterial reduction of the root canals, many irrigants have been indicated during endodontic treatment, among them nanoparticles solutions. AIMS: This study aims to evaluate the effectiveness of experimental solutions containing silver and zinc oxide nanoparticles (ZnO Np) and conventional endodontic irrigants against Enterococcus faecalis biofilm, in root canals. METHODS: Seventy-six extracted human teeth were biomechanically prepared and sterilized. The root canal surface was exposed to E. faecalis suspension to form a 7-day-old biofilm. Four teeth were analyzed by scanning electron microscopy (SEM) to confirm the presence of biofilm. The remaining teeth were randomly divided into 6 groups (n = 12) and treated with passive ultrasonic irrigation and different solutions: G1 - 0.85% saline (control); G2 - 2% chlorhexidine gluconate (CHX); G3 - 5% sodium hypochlorite (NaOCl); G4 - 1% NaOCl; G5 - 1% silver nanoparticles (Ag Np) solution; and G6 - 26% ZnO Np solution. The susceptibility of E. faecalis biofilms to disinfecting solutions (n = 10) was determined by quantification of colony-forming units. SEM analysis was also carried out to examine the biofilm structure after treatments (n = 2). Data were analyzed by Kruskal-Wallis and Dunn post hoc tests (P < 0.05). RESULTS: All tested solutions showed superior effectiveness compared to 0.85% saline (P < 0.05). Overall, 2% CHX presented the most effective action against E. faecalis biofilm, followed by 5% NaOCl, 1% Ag Np, 26% ZnO Np, and 1% NaOCl. CONCLUSIONS:: 1% Ag Np and 26% ZnO Np were effective against E. faecalis biofilm similarly to conventional endodontic irrigants.

Influence of Infected Root Dentin on the Bond Strength of a Self-adhesive Resin Cement.

AIM: The aim of this study was to determine the bond strength (BS) of a self-adhesive resin cement to the contaminated root dentin. MATERIALS AND METHODS: The crown and apical third of twenty single-rooted teeth were removed. The root canals were flared and 1-mm-thick root sections were obtained. The sections were rinsed, dried, and sterilized. The control group (n=20) was composed of one section of each third, which remained immersed in sterile trypticase soy broth (TSB) for 2 months. The other sections comprised the experimental group (n = 40) and were immersed in a suspension of Enterococcus faecalis. The culture medium was changed at every 4 days for 2 months. The sections were rinsed with distilled water, dried, and the root canal space was filled with the self-adhesive resin cement RelyX™ U200. After 24 h, the push-out test was performed and the types of interface failure were observed on a stereo microscope. STATISTICAL ANALYSIS: Data were statistically analyzed by the nonparametric Mann-Whitney test (α=5%). RESULTS: A significant reduction was observed in the BS of resin cement to the contaminated dentin compared to the healthy dentin, for both thirds analyzed (P < 0.05). The BS was significantly greater at the cervical third compared to the middle third for specimens in the experimental group (P < 0.05). Adhesive and mixed failures were observed more frequently in specimens contaminated with E. faecalis. CONCLUSION: Bacterial contamination negatively infl uenced the BS of the self-adhesive resin cement to the root dentin, and there was a predominance of adhesive and mixed failures.

Bacterial penetration into filled root canals exposed to different pressures and to the oral environment-in vivo analysis.

OBJECTIVES: The study aims to correlate the depth of bacterial penetration into filled root canals with the time of exposure to the oral environment and different pressures. MATERIALS AND METHODS: One-hundred and twenty-two root canals of male Beagle dog teeth were prepared and filled. The root canals were distributed into three groups, according to the pressure applied: (A) no pressure, (B) 30 kPa, and (C) 60 kPa. Then, the root canals were exposed to the oral environment, establishing sub-groups considering the time intervals of exposure: (1) 45 days and (2) 120 days (n = 17). Sub-groups had positive and negative controls (n = 5). The animals were sacrificed, and the specimens were prepared for histological analysis. RESULTS: There was no significant difference in the bacterial penetration among groups A, B, and C at 45 days (P = 0.903) and 120 days (P = 0.211). No statistically significant difference was found (P = 0.608) between the exposure time intervals. Most of the specimens from experimental groups exposed for 120 days presented moderate inflammatory infiltrate. CONCLUSIONS: Pressures of 30 and 60 kPa did not affect sealing ability of root canal filling. The time of exposure did not influence bacterial penetration, which was limited to the first 4 mm of the root canals exposed for 120 days. CLINICAL RELEVANCE: This animal study demonstrated that disinfection of the first millimeters of root canals could be considered before retreatment of their entire length. However, clinical studies in humans should be conducted before validation of this protocol.

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.

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.

Florid Cemento-osseous Dysplasia: A Case of Misdiagnosis.

Florid cemento-osseous dysplasia (FCOD) belongs to the group of fibro-osseous lesions in which normal bone is replaced by fibrous connective tissue and calcified cementum tissue of the avascular type. Among the various types of fibro-osseous lesions, FCOD is one of the most commonly encountered diseases in clinical practice and may involve 3 or 4 of the quadrants. FCOD is located in the periapical regions of teeth, and the lesions are predominantly radiolucent (osteolytic phase), become mixed over time (cementoblast phase), and ultimately become radiopaque (osteogenic phase) with a thin radiolucent peripheral halo. The characteristics of FCOD in the initial stages are similar to those of periapical lesions of inflammatory origin, which may lead to misdiagnosis. A 38-year-old woman sought dental care because of complaints of pain on the right side of her face. A clinical examination revealed no marked alterations; a panoramic radiograph was therefore requested and revealed the presence of radiolucent lesions associated with the periapical regions of some of the lower teeth. Thus, the professional referred the patient for endodontic treatment of the associated teeth with the justification that the lesions were of endodontic origin. However, the endodontist found that the teeth responded positively to a sensitivity test. The initial diagnosis could have resulted in unnecessary root canal treatment, but after careful clinical, radiographic, and tomographic assessments by different professionals, FCOD was diagnosed, conservatively treated, and regularly monitored. It is important that dentists have a basic knowledge of the various injuries that affect the jaw bones to prevent errors in diagnosis and treatment and to promote oral health.