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Hank's balanced salt solution (HBSS) is recommended for the storage of avulsed teeth. The objective of this study was to evaluate if the HBSS storage time influences its ability to maintain the viability of human periodontal ligament fibroblasts (PDLF) by the analysis of cell metabolic function using MTT assay. PDLF were kept at 20°C for 3, 6, 24, 48, 72, 96 and 120 h in recently prepared HBSS (HBSS), HBSS stored for 6 months (HBSS 6 M), HBSS stored for 12 months (HBSS 12 M), and in Save-A-Tooth system's HBSS (Save). Minimum essential medium (MEM) at 37°C and tap water at 20°C served as positive and negative controls, respectively. Cell viability was determined by the tetrazolium salt-based colorimetric (MTT) assay. Data were statistically analyzed by the Kruskal-Wallis and Scheffé tests (α = 5%). Starting with the 6 h time-point, HBSS was significantly more effective than HBSS 6 M, HBSS 12 M and Save in maintaining cell viability. HBSS 6 M effectiveness was similar to that of HBSS 12 M for up to 48 h, becoming higher at 72 h. In conclusion, the storage time of HBSS had a negative influence on its ability to maintain PDLF viability. [ABSTRACT FROM AUTHOR]

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., Competing Interests: There are no conflicts of interest.

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., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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.

Aim: To evaluate nanoparticulate calcium carbonate (NPCC) using transmission electron microscopy and the effects of NPCC addition to MTA in regard to the setting time, dimensional change, compressive strength, solubility and pH., Methodology: The experimental groups were G1 (MTA), G2 (MTA with 5% NPCC) and G3 (MTA with 10% NPCC). The tests followed ISO and ADA standards. The specimens in the dimensional change and compressive strength tests were measured immediately after setting, after 24 h and after 30 days. In the solubility test, rings filled with cement were weighed after setting and after 30 days. The pH was measured after 24 h and 30 days. The data were analysed with the ANOVA, Tukey's and Kruskal-Wallis tests (α = 5%)., Results: The setting time was reduced (P < 0.05) in samples from G2 and G3 compared to G1. After 24 h, the dimensional change was similar amongst the groups, and after 30 days, G2 was associated with less alteration than G1 and G3. There was a difference in the compressive strength (P < 0.001) after 24 h and 30 days (G1 > G2 > G3). The solubility test revealed a difference amongst the groups when the specimens were hydrated: G2 > G1 > G3 and dehydrated: G3 > G2 > G1. The pH of the groups was similar at 24 h with higher values in each group after 30 days (P < 0.05), and G2 and G3 had similar mean pH values but both were higher than G1., Conclusions: Nanoparticulate calcium carbonate had a cubic morphology with few impurities. The addition of nanoparticulate calcium carbonate to MTA accelerated the setting time, decreased compressive strength and, after 30 days, resulted in lower dimensional change (G2), higher solubility and a higher pH., (© 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

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.

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.

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.

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., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The objective of this study was to evaluate the efficacy of passive ultrasonic irrigation (PUI) with 17% EDTA and 1% NaOCl solutions on smear layer removal., Methods: Root canal preparations of 32 human teeth were performed with the ProTaper system. Next, they were longitudinally fractured to permit quantitation of smear layer creation from the cervical, middle, and apical thirds of the roots by using scanning electron microscopy. After reassembling the fractured tooth halves, they were divided into 4 groups according to different final irrigation protocols: group1, EDTA + NaOCl; group 2, EDTA with PUI + NaOCl; group 3, EDTA + NaOCl with PUI; and group 4, EDTA + NaOCl, both with PUI. After irrigation, the tooth halves were separated to permit imaging the same areas by scanning electron microscopy, and a percentage of opened dentinal tubules in irrigated areas as a percent of the total area was obtained. The results were submitted to Kruskal-Wallis, analysis of variance, and Bonferroni tests (α = 0.05)., Results: The cervical third of the samples from all groups showed higher percentage of smear layer removal and open dentinal tubule areas, followed by the middle and apical thirds. Among the irrigation groups, there were statistically significant differences in cervical third between group 2 and group 4 samples, with the highest and lowest percentage of smear layer removal, respectively., Conclusions: PUI by using 1% NaOCl and ultrasonic tip placed within 1 mm of the apical foramen did not show higher efficacy in smear layer removal compared with conventional irrigation., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

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., (© 2014 Wiley Periodicals, Inc.)

Aim: To evaluate the diffusion of hydroxyl ions from calcium hydroxide paste (CH) before root canal filling and after retreatment., Methodology: After preparation of 60 root canals, the cementum layer was removed, and the canals and root surfaces were treated for smear layer removal. The apical third of roots was covered with adhesive. The canals were filled with CH, and the teeth were placed in individual vials containing 10 mL of distilled water, which had its pH measured after 7, 14, 21 and 28 days (pH1). The root canals were then divided into five groups and filled with Resilon/Real Seal (G1) or gutta-percha and Endofill (G2), Sealapex (G3), AH Plus (G4) or MTA Fillapex (G5) sealers. After storage for 7 days, the root canals were retreated. The CH was again inserted into the canals, and the teeth were placed in new vials containing 10 mL of distilled water. The pH was again measured at 7, 14, 21 and 28 days (pH2). The initial and final pH readings (pH1 and pH2) were compared by anova, anova2 and Tukey's tests (P < 0.05)., Results: The pH1 and pH2 measurements increased with time. The measurements obtained after retreatment were significantly higher than those obtained before root canal filling., Conclusions: Hydroxyl ions are able to diffuse through dentinal tubules. Regardless of the filling material, it was possible to re-establish the permeability of dentine to ionic diffusion after retreatment. Time had a positive influence on ionic diffusion., (© 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Aim: To evaluate connective tissue reactions to iRoot SP (Innovative Bioceramics, Vancouver, BC, Canada), mineral trioxide aggregate (MTA) Fillapex (FLPX) (Angelus Soluções Odontológicas, Londrina, Brazil), DiaRoot Bioaggregate (DiaDent Group International, Burnaby, BC, Canada) and white MTA (Angelus, Londrina, Brazil) in Wistar rats., Methodology: A total of 128 dentine tubes filled with the materials and 32 empty tubes (control) were implanted into 32 rats. After 7, 15, 30 and 90 days (n = 8 per period), the animals were euthanized, and the tissues were processed for histological evaluation using haematoxylin-eosin (H&E) and Von Kossa (VK) staining. Observations were made for cellular inflammatory components and the presence of multinucleated giant cells (MNGC), macrophages and tissue necrosis. Data were analysed by Fisher's exact and Kruskal–Wallis tests (P < 0.05)., Results: In all experimental periods, MTA FLPX and iRoot SP scored higher than the other groups for the variable macrophages (P < 0.05). After 30- and 90-day experimental periods, MTA FLPX scored higher than the other groups for the variable MNGC (P < 0.05). After 90 days, the only group that exhibited samples with severe inflammatory response was MTA FLPX. VK positivity was observed in areas of necrosis in all groups, except in the control group., Conclusions: The materials were considered biologically acceptable except MTA FLPX, which remained toxic to subcutaneous tissue even after 90 days.

Aim: To analyse the influence of exposure of mineral trioxide aggregate (MTA) with and without calcium chloride (CaCl2 ) to phosphate-buffered saline (PBS) on the push-out bond strength, over different experimental periods., Methodology: One hundred and twenty dentine discs with standardized cavities were filled with MTA with and without 10% CaCl2 . The specimens were randomly divided as follows (n = 30): (G1) MTA in contact with a moistened cotton pellet, (G2) MTA immersed in PBS, (G3) MTA + CaCl2 in contact with a moistened cotton pellet and (G4) MTA + CaCl2 immersed in PBS. The samples were stored for 3, 28 and 60 days. The bond strengths were measured with the Instron Testing machine. Data were analysed using the three-way anova and Tukey test (P < 0.05)., Results: In general, the samples of MTA with and without CaCl2 , exposed to PBS, had higher bond strength values in all study periods (P < 0.05). Analysis of the influence of addition of CaCl2 to MTA (G1 × G3) evidenced significant differences in bond strength in the different periods (P < 0.05)., Conclusions: The exposure of MTA to PBS positively influenced the push-out bond strength, whereas the addition of CaCl2 had a negative influence., (© 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

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.

Milk has been studied extensively and has gained wide acceptance as a suitable storage medium capable of maintenance of avulsed teeth that cannot be replanted immediately. The objective of this study was to evaluate whether the renewal of milk as a storage medium every 24 h for up to 120 h is able to increase its ability to maintain human periodontal ligament fibroblasts (PDLF) viability in vitro. Plates with confluent PDLF were soaked in minimum essential medium (MEM) at 37°C (positive control) and in skimmed milk (22 wells) and water (negative control) for 24, 48, 72, 96, and 120 h at 5 and 20°C. The skimmed milk was renewed every 24 h in 11 of the wells of each plate. After these periods, cell viability was determined by the tetrazolium salt-based colorimetric (MTT) assay. Data were statistically analyzed by Kruskal-Wallis and Scheffé tests (α = 5%). At 24 h, milk and MEM performed similarly. However, from 48 h onwards, MEM was significantly better than renewed and not renewed milk at both temperatures. Regardless of temperature (5 or 20°C), renewal of milk with fresh milk did not affect its ability to maintain PDLF viability., (© 2011 John Wiley & Sons A/S.)

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., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim: To evaluate the effectiveness of various storage media at 5 °C for maintaining the viability of human periodontal ligament fibroblasts (PDLF)., Methodology: Plates with PDLF were soaked in recently prepared Hank's balanced salt solution (HBSS), skimmed milk, whole milk, Save-A-Tooth(®) system's HBSS (Save), natural coconut water, industrialized coconut water or tap water (negative control) at 5 °C for 3, 6, 24, 48, 72, 96 and 120 h. Minimum essential medium (MEM) at 37 °C served as the positive control. PDL cell viability was determined by MTT assay. Data were statistically analysed by Kruskal-Wallis test complemented by the Scheffé test (α=5%)., Results: The greatest number of viable cells was observed for MEM. Skimmed and whole milk, followed by natural coconut water and HBSS, were the most effective media in maintaining cell viability (P<0.05). From 24 to 120 h, Save, industrialized coconut water and tap water were the worst storage media., Conclusions: Skimmed and whole milk had the greatest capacity to maintain PDLF viability when compared with natural coconut water, HBSS, Save, industrialized coconut water and tap water., (© 2010 International Endodontic Journal.)

The aim of this study was to verify the efficacy of doxycycline used alone or in association with sodium hypochlorite on smear layer removal. The canals of extracted human teeth were instrumented using a stepback technique. At the end of preparation, they were irrigated with doxycycline (Group 1), ethylenediaminetetraacetic acid + sodium hypochlorite (Group 2), doxycycline + sodium hypochlorite (Group 3) and water (Group 4). The dentinal wall of the cervical, middle and apical thirds was graded according to the amount of remaining debris and smear layer. The results were analysed using the Kruskal-Wallis test (P < 0.05). In Groups 2 and 4, the dentine was completely free and covered with smear layer, respectively. The results from the cervical and middle thirds of Group 3 were worse than those in Groups 1 and 2 (P < 0.05). In relation to apical third, there were differences (P < 0.05) between all groups with best results for Group 2. Doxycycline was effective in removing smear layer from cervical and middle thirds. The use of doxycycline + sodium hypochlorite was partially effective in the cervical and middle thirds, but ineffective in the apical third.

Introduction: The biological processes underlying the ability of mineral trioxide aggregate (MTA) to promote hard-tissue deposition and wound healing remain unclear. To further study these processes, specific signaling molecules related to the inflammatory response and the biomineralization process were analyzed to assess host-MTA interactions in vivo., Methods: For cytokine level quantification and immunohistochemical analysis, human dentin tubes were filled with ProRoot MTA (Dentsply, Tulsa Dental, OK) or kept empty and were implanted in subcutaneous tissues in the backs of mice. Dentin tubes were retrieved and subsequently observed using a scanning electron microscope., Results: MTA induced a time-dependent proinflammatory cytokine up-regulation up to 3 days. Immunohistochemical analyses showed an up-regulated expression of myeloperoxidase, nuclear factor-kappa B, activating protein-1, cyclooxygenase-2, inducible nitric oxide synthase, and vascular endothelial growth factor on day 1. Scanning electron microscopic examination revealed the presence of apatite-like clusters on collagen fibrils over the surface of tubes containing MTA. With the increase in time after implantation, a more extensive mineralization showing a compact layer of apatite was observed., Conclusion: MTA induced a proinflammatory and pro-wound healing environment. The biomineralization process occurred simultaneously at the biomaterial-dentin-tissue interface, with the acute inflammatory response. This promoted the integration of the biomaterial into the environment., (Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Many solutions have been examined as possible storage media for avulsed teeth. The purpose of this study was to compare the effectiveness of several storage media to preserve cultured periodontal ligament fibroblasts (PDLF) under different temperatures. The media tested were: sterile Hank's balanced salt solution (sHBSS), non-sterile HBSS (nHBSS), skimmed milk, Save-A-Tooth((R)), Minimum Essential Medium (MEM) and water (negative control). MEM at 37 degrees C was used as positive control. PDLF were obtained from explants of extracted healthy human teeth. Plates containing confluent PDLF were soaked in the various media for 3, 6, 24, 48 and 72 h at 37 degrees C and 20 degrees C. After incubation, viability of the cells was determined using the tetrazolium salt-based colorimetric (MTT) assay and the Trypan Blue exclusion test after 6, 24, 48 and 72 h of incubation at 20 degrees C. The results were analyzed statistically using Kruskal-Wallis, Scheffé and Mann-Whitney (alpha = 5%) tests. Results from the MTT assay at 37 degrees C and 20 degrees C showed that skimmed milk was the best storage medium for up to 24 and 48 h, respectively, followed by nHBSS and sHBSS. Results from the Trypan Blue exclusion test showed that the best storage media were milk, sHBSS and nHBSS, with no statistical differences, for any time period. The Save-A-Tooth((R)) had a detrimental effect on cells after 24 h. The influence of temperature on the effectiveness of the storage media tested showed at 20 degrees C a decreasing order of efficacy as follows: milk > sHBSS and nHBSS > MEM > Save-A-Tooth((R)) > water while at 37 degrees C it was: MEM > nHBSS > milk > sHBSS > Save-A-Tooth((R)) > water. In conclusion, incubation temperature altered the effectiveness of the storage media and skimmed milk at 20 degrees C was better than HBSS in maintaining PDLF viability.

The aim is to verify, under scanning electron microscopy, the occurrence of apical root resorption in anterior and posterior teeth with chronic and radiographically visible periapical lesions. Thirty-two teeth were extracted, the apical thirds (n = 39) were removed, and prepared to analyse the external apical root surface. All specimens presented irregular areas of root resorption with different depths, located mainly around the apical foramen. Teeth with chronic periapical lesions present areas of external apical root resorption with irregular surface and different depths located mainly around the apical foramen. Root resorptions may show different configurations and destroy the apical root structure more or less extensively.

Objectives: To evaluate the bonding interface in experimentally weakened roots reinforced with adhesive restorative materials and quartz fibre posts, varying the light-exposure time of the composite resin used for root reinforcement., Methods: Twelve extracted human maxillary incisors teeth were used. The crowns were removed and the roots were endodontically treated. After post space preparation, the roots were assigned to four groups. The thickness of the root dentine was reduced and adhesively restored with composite resin light-activated through a translucent fibre post for either 40s (group 1), 80s (group 2) or 120s (group 3). In the case of control (group 4), the roots were not weakened. One day after post cementation, the specimens were sectioned transversally in three slices and processed for scanning electron microscopic analysis to observe bonding interface formation, quality of the hybrid layer and density of resin tags using a four-step scale method., Results: Formation of a hybrid layer and resin tags were evident in all groups. There was no statistically (p>0.05) significant difference between the regions analysed in each group (Friedman test) and between groups in each section depth (Kruskal-Wallis test). Furthermore, comparison of the flared/reinforced groups showed that the different times used for composite resin cure did not affect the results significantly (Kruskal-Wallis test, p=0.2139)., Conclusions: Different light-exposure times used for composite resin polymerisation during root canal reinforcement did not affect significantly the formation and quality of the dentine/adhesive/composite resin bonding interface.

Background: Osteogenesis imperfecta (OI), also known as "brittle bone disease," can be difficult to diagnose in its mild form. The authors describe a clinical case of a diagnosis of dentinogenesis imperfecta (DI), in which a literature review combined with an analysis of dental alterations led to indications of OI involvement., Case Description: Since DI can be associated with OI, the authors reviewed correlated studies and obtained a new medical history from the patient. They then conducted a radiographic and clinical examination of the dentition and submitted an affected third molar to scanning electron microscopy analysis. They compared their findings with descriptions of OI type I dental alterations in the literature and confirmed their diagnosis by means of a medical evaluation., Clinical Implications: In cases in which DI is diagnosed, patients should be examined carefully and the occurrence of OI should be considered since, in its mild form, it might be misdiagnosed.

Aim: To evaluate the capacity of the ROOT ZX II to locate the apical foramen and to control the apical extent of rotary instrumentation., Methodology: Sixty-five extracted human single rooted teeth were selected and measured directly using a size 15 K-Flexofile introduced in the canal until the tip was visible at the major foramen (direct length, DL). The teeth were then measured electronically (EL1) with the ROOT ZX II when used passively, that is without rotation. To test the auto reverse function, the root canals were instrumented with nickel titanium rotary instruments. Instrumentation was carried out apically until rotation was reversed by the automatic apical reverse (AAR) function at different levels (2, 1 and 0.5). The instrumented length at each level was measured and registered as AAR2, AAR1 and AAR0.5, respectively. After instrumentation, a second passive electronic measurement was conducted and noted as electronic length 2 (EL2). All measurements were expressed in millimetres with accuracy set to 0.5 mm. Percentages of acceptable measurements for each electronic reading were calculated and compared using the proportions test. The Wilcoxon's signed rank test was used to compare the differences between DL/EL1 and DL/EL2, and to compare EL2 with the different AAR measurements. The critical value of statistical significance was 5%., Results: EL1 and EL2 measurements were coincident to DL in 56 (86%) and 54 (83%) of the cases, respectively. The proportions test showed no statistically significant difference between these percentages (P > 0.05). The Wilcoxon's signed rank test did not show any differences (P > 0.05) when comparing the mean difference between DL with EL1 (0.03) and DL with EL2 (0.10). Statistically significant differences were observed when comparing EL2 with AAR2 and with AAR1., Conclusions: The ROOT ZX II reliably located the major apical foramen, but was not an accurate method for controlling the apical extent of rotary instrumentation. Rotary instrumentation with the automatic apical reverse feature was always closer to the foramen than expected.

Aim: To evaluate the influence of mineral trioxide aggregate (MTA) on apexification and periapical healing of teeth in dogs with incomplete root formation and previously contaminated canals and to verify the necessity of employing calcium hydroxide paste before using MTA., Methodology: Twenty premolars from two 6-month old dogs were used. After access to the root canals and complete removal of the pulp, the canal systems remained exposed to the oral environment for 2 weeks. Canal preparation was then carried out using Hedström files, under irrigation with 1% sodium hypochlorite, 1 mm short of the radiographic apex. After drying, the canals of two premolars in each dog were left empty (control group). The other eight teeth in each animal were divided into two experimental groups. The apical thirds of the canals of group 1 were filled with MTA. In the teeth of group 2, the canals were dressed with a calcium hydroxide-propylene glycol paste. After 1 week, the paste was removed and the apical third was filled with MTA. All teeth were restored with reinforced zinc oxide cement (IRM) and amalgam. The animals were killed 5 months later, and blocks of the teeth and surrounding tissues were submitted to histological processing. The sections were studied to evaluate seven parameters: formation of an apical calcified tissue barrier, level of barrier formation, inflammatory reaction, bone and root resorption, MTA extrusion, and microorganisms. Results of experimental groups were analysed by Wilcoxon's nonparametric tests and by the test of proportions. The critical value of statistical significance was 5%., Results: Significant differences (P < 0.05) were found in relation to the position of barrier formation and MTA extrusion. The barrier was formed in the interior of the canal in 69.2% of roots from MTA group only. In group 2, it was formed beyond the limits of the canal walls in 75% of the roots. MTA extrusion occurred mainly in roots from group 2. There was similarity between the groups for the other parameters., Conclusions: Mineral trioxide aggregate used after root canal preparation favoured the occurrence of the apexification and periapical healing. The initial use of calcium hydroxide paste was not necessary for apexification to occur, and has shown to be strongly related to the extrusion of MTA and formation of barriers beyond the limits of the root canal walls.

Aim: To evaluate the effect of different irrigant solutions employed during removal and replacement of calcium hydroxide paste on the diffusion of hydroxyl ions through root canal dentine in vitro., Methodology: Thirty-five maxillary and mandibular human canines with straight and fully developed roots were used. After mechanical preparation up to 1mm short of tooth length, 30 canals were filled with calcium hydroxide paste and 5 canals were left empty; all teeth had their coronal accesses properly sealed. Teeth were placed in plastic containers with distilled water, and pH was read after 30 days when the paste from 20 teeth was renewed. After removal of the paste by endodontic instrumentation and irrigation with distilled water, canals were replenished with newly mixed paste in Group 1 and 2. In these groups, final irrigation was conducted with 5 mL of EDTA followed by 5 mL of NaOCl in specimens in Group 1, and 5 mL of NaOCl only in specimens in Group 2. In 10 teeth the paste was not replenished at 30 days (Group 3). All specimens were returned to the containers with fresh distilled water, and the pH was recorded after another 30 days. The differences between the first (30d) and second (60d) pH readings were calculated and submitted to analysis of variance and individual comparisons using the Scheffeé's test., Results: Results of mean analysis on differences of pH readings showed that greater diffusion had occurred on specimens in Group 3. Individual comparisons using Scheffeé's test showed statistical significance between Groups 2 and 3, and equivalence between all other groups., Conclusion: It was concluded that the use of EDTA did not enhance diffusion of hydroxyl ions through root canal dentine.

Aim: To evaluate ex vivo the capacity of the Tri Auto ZX to locate the apical foramen during root canal retreatment., Methodology: The root canals of 62 maxillary and mandibular canines were prepared to a length 1 mm short of the apical foramen, to an apical size 35 using 1% sodium hypochlorite as an irrigant. Once prepared, the length of each tooth was measured directly using a size 15 K-Flexofile introduced in the canal until the tip was visible at the apical foramen. After the file was removed, its length was recorded to a precision of 0.01 mm using a calliper. These direct lengths (DL) became the 'gold standard' for comparison with the electronic lengths (EL) derived from the Tri Auto ZX. After direct measurement, the tooth was measured electronically (EL1) and the canals were filled using lateral condensation of gutta-percha cones and sealer. Seven days later the root filling was removed using solvent, Gates-Glidden burs, and K-files, and new electronic lengths determined (EL2). The electronic lengths (EL1 and EL2) were compared with the DL, and the differences were analysed statistically using the proportions test and Student's t-test., Results: At a tolerance limit of +/-0.5 mm, EL1 coincided with the DL in 76% of cases. Lengths obtained in the presence of remnant of filling material (EL2) coincided in 81% of cases. The proportions test used to compare these percentages showed no statistically significant difference between EL1 and EL2 (P > 0.05). The Student's t-test revealed a statistically significant difference (P < 0.05) between the means of the differences between DL/EL1 (-0.36 mm) and DL/EL2 (-0.04 mm)., Conclusion: The Tri Auto ZX was accurate to +/-0.5 mm in more than 80% of teeth following removal of root fillings.

Aim: To evaluate the influence of renewing calcium hydroxide paste on apexification and periapical healing of teeth in dogs with incomplete root formation and previously contaminated canals., Methodology: Forty premolars from four 6-month-old dogs were used. After access to the root canals and complete removal of the pulp, the canal systems remained exposed to the oral environment for 2 weeks. Canal preparation was then carried out using Hedströem files, under irrigation with 1% sodium hypochlorite, 1 mm short of the radiographic apex. After drying, the canals of one premolar in each dog were left empty (group 4-control), and those of the other nine teeth in each animal were filled with a calcium hydroxide-propylene glycol paste. All teeth were restored with reinforced zinc oxide cement (IRM) or IRM and amalgam (group 4). The paste was renewed and the teeth restored again 1 week later. Then, the nine teeth in each animal were divided into three experimental groups: group 1 - paste not changed; group 2 - paste renewed every 4 weeks for 5 months; and group 3 - paste renewed after 3 months had elapsed. The teeth were restored with IRM and amalgam (groups 1 and 3) or IRM (group 2). The animals were killed 5 months later, and blocks of the teeth and surrounding tissues were submitted to histological processing. The sections were studied to evaluate six parameters: apical calcified tissue barrier, inflammatory reaction, bone and root resorption, paste extrusion and microorganisms. Results of experimental groups were analysed by Kruskal-Wallis nonparametric tests and by the test of proportions. The critical value of statistical significance was 5%., Results: Significant differences (P < 0.05) were found in relation to the presence of bone resorption and paste in the periradicular area, the formation of a calcified tissue barrier at the apex, and the intensity of the apical inflammatory reaction. Bone resorption was more evident in group 1 (medicament not changed), and the presence of paste in the periodontal tissues was more common in groups 2 and 3. Renewal of the paste reduced the intensity of the inflammatory reaction (groups 2 and 3), but the formation of apical calcified tissue was more noticeable in the teeth where the paste had not been renewed., Conclusions: Replacement of calcium hydroxide paste was not necessary for apexification to occur, however, it did reduce significantly the intensity of the inflammatory process. Monthly renewal of calcium hydroxide paste reduced significantly the occurrence of apexification.

Aim: To verify, under the scanning electron microscope (SEM), the influence of irrigation time with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) on intracanal smear layer removal., Methodology: Twenty-one extracted human permanent teeth with single straight root canals were included. The root canals of the teeth were instrumented and, at the end of preparation, were irrigated with 3 mL of 15% EDTA, followed by 3 mL of 1% NaOCl for 1 min (group 1), for 3 min (group 2), and for 5 min (group 3). The canals of teeth in group 4 (control) did not receive the final irrigation. The teeth were sectioned longitudinally and prepared for an SEM. The dentinal wall of cervical, middle and apical thirds was graded according to the amount of debris and smear layer remaining on the walls. The results were analysed using the Kruskal-Wallis and Conover-Inman tests., Results: In all the canals of experimental groups irrigation with EDTA and NaOCl completely removed the smear layer from the cervical and middle thirds. In the apical third, the dentine surface were partially covered, particularly in the teeth of group 1, where there was significantly more smear layer when compared with the other thirds in the same group (P<0.007). However, the Kruskal-Wallis test showed overall that there were no significant differences between groups 1, 2 and 3 (P>0.05)., Conclusion: In this limited laboratory study, canal irrigation with EDTA and NaOCl for 1, 3 and 5 min were equally effective in removing the smear layer from the canal walls of straight roots.

A new audiometric device to determine the location of the apical foramen of teeth undergoing endodontic treatment according to "the relative value method" was tested in in vitro experiments. In 96.5% of the 350 human teeth used in the experiment, the location of the apical foramen was determined within acceptable limits (0-0.5 mm). In 60 teeth, where the measurements were based on an intermittent audio signal, a point about 1 mm short of the apical foramen was located. The results were considered promising and a clinical evaluation of the device will be carried out.