Apical Microleakage of a Silicone Based Root Canal Sealer: an Electrochemical Study

Svrha: Elektrokemijskom metodom procijenilo se apikalno propuštanje materijala RoekoSeal Automix (RSA) za punjenje korijenskog kanala samostalno i u kombinaciji s gutaperkom. Materijali i metode: Pedeset i dva prednja maksilarna zuba podijeljena su u dvije skupine. U prvoj su korijenski kanali punjeni samo RSA-om, a u drugoj gutaperkom i RSA-om (n = 24 u svakoj skupini). Preostala četiri zuba služila su kao pozitivna i negativna kontrolna skupina. Eksperimentalna jedinica konstruirana je tako da je bila neprekidno spojena na izvor struje. Jedanpostotni kalijev jodid (KI) korišten je kao elektrolit te su zubi uronjeni u otopinu. Bakrene elektrode s provodnim kapacitetom od jednoga miliampera (mA) korištene su kao anode za zatvaranje strujnog kruga. Rezultati su se očitavali ukupno tri tjedna, jedanput na dan, digitalnim voltmetrom spojenim na eksperimentalnu jedinicu. Promjene u količini propuštanja u skupini procjenjivale su se svaki dan t-testom za ovisne uzorke, a razlika između dviju skupina analizirana je t-testom za neovisne uzorke. Rezultati: Razlika u apikalnom propuštanju između dviju eksperimentalnih skupina nije bila statistički značajna (p>0,05). U objema je zabilježeno značajno propuštanje u svim vremenskim intervalima (p<0,05). Zaključak: RoekoSeal Automix samostalno nije se razlikovao u propuštanju od gutaperke punjene njime. Također nije bio potpuno učinkovit u sprječavanju propuštanja.Objectives: To evaluate the apical leakage of the root canal fillings performed with RoekoSeal Automix (RSA) alone and in combined with gutta-percha electrochemically. Materials and methods: Fifty two maxillary anterior teeth were divided into two groups. In group 1, the root canals were filled with RSA alone and in group 2 the root canals were filled with gutta-percha and RSA (n=24 each group). The remaining 4 teeth were used for positive and negative control groups. An experimental cell was constructed which was connected with a constant current source. 1% potassium iodide (KI) solution was added to the cell as the electrolyte and the teeth were then immersed in this solution. Copper electrodes with 1 milliampere (mA) conductance capacity were used as anodes to complete the circuit. The results were read daily, with a digital voltmeter connected to the experimental cell, for a total of 21 days. The changes in amount of leakage from day to day within the groups were evaluated by a “t-test for dependent samples” and the difference between two groups was analyzed by “t-test for independent samples”. Results: The difference of apical leakage amount between two experimental groups was not statistically significant (p>0.05). Both groups showed significant leakage at all time periods (p<0.05). Conclusion: RSA alone was not different in terms of leakage from gutta-percha compacted with RSA. However, RSA was not totally effective in preventing leakage

Combined effects of bone morphogenetic protein-7 and mineral trioxide aggregate on the proliferation, migration, and differentiation of human dental pulp stem cells

Bioactive molecules present the potential to be used along with biomaterials in vital pulp therapy and regenerative endodontic treatment. Objective: The aim of this study was to assess the effects of the combined use of bone morphogenetic protein-7 (BMP-7) and mineral trioxide aggregate (MTA) on the proliferation, migration, and differentiation of human dental pulp stem cells (DPSCs). Methodology: For the proliferation analysis, DPSCs were incubated with a growth medium and treated with MTA and/or BMP-7 at different concentrations. For the following analyses, DPSCs were incubated with a differentiation medium and treated with MTA and/or BMP-7. Moreover, there were groups in which DPSCs were incubated with the growth medium (control), the differentiation medium, or DMEM/F12 containing fetal bovine serum, and not treated with MTA or BMP-7. Cell proliferation was analyzed using the WST-1 assay. The odontogenic/osteogenic differentiation was evaluated by immunocytochemistry, alkaline phosphatase (ALP) activity assay, alizarin red staining, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell migration was evaluated using a wound-healing assay. Data were analyzed using analysis of variance and Tukey test (p=0.05). Results: The use of BMP-7 with MTA presented no significant effect on cell proliferation in comparison with the treatment with MTA alone (p&gt;0.05), but showed higher ALP activity, increased mineralization, and higher expression of DMP1 and DSPP when compared with other groups (p&lt;0.05). Nestin expression was higher in the control group than in groups treated with MTA and/or BMP-7 (p&lt;0.05). The cell migration rate increased after treatment with MTA when compared with other groups in all periods of time (p&lt;0.05). At 72 hours, the wound area was smaller in groups treated with MTA and/or BMP-7 than in the control group (p&lt;0.05). Conclusion: The use of BMP-7 with MTA increased odontogenic/osteogenic differentiation without adversely affecting proliferation and migration of DPSCs. The use of BMP-7 with MTA may improve treatment outcomes by increasing repair and regeneration capacity of DPSCs

Farklı Kök Ucu Dolgu Materyallerinin Sitotoksik Etkilerinin ve Farklı Kök Ucu Kavite Preparasyon Tekniklerine Bağlı Olarak Apikal Sızıntı ve Kenar Uyumlarının Karşılaştırmalı Olarak Değerlendirilmesi

A comparative evaluation of the cytotoxicity of different rootend filling materials and their apical leakage and marginal adaptation in relation to different root-end cavity preparation techniques. Hacettepe University Institute of Health Sciences, Ph.D. Thesis in Endodontics, Ankara, 2014. The aims of this study are to evaluate the sealing efficacy and marginal adaptation of MTA, CEM and Biodentine in cavities prepared by different root-end cavity preparation techniques and to analyze the cytotoxic effects of these materials. A total of 72 extracted human upper anterior teeth were used. Teeth were randomly divided as 60 teeth in experimental groups and 6 teeth each for positive and negative control groups. The crowns were removed so that the length of all roots in experimental and positive control groups was adjusted to 15 mm and their root canals were instrumented. Only specimens in experimental groups were obturated and their root-end resections were performed. Specimens in experimental groups were randomly divided into six groups including 10 specimens in each group as follows: Grup 1: Ultrasonic retrotip+MTA, Grup 2: Ultrasonic retrotip+CEM, Grup 3: Ultrasonic retrotip+Biodentine, Grup 4: Er:YAG laser tip+MTA, Grup 5: Er:YAG laser tip+CEM, Grup 6: Er:YAG laser tip+Biodentine. Microleakage was measured by fluid-filtration method. Thereafter, 6 specimen from each experimental group were randomly selected to analyze marginal adaptation. The roots were transversally sectioned in order to obtain the apical 5 mm. Next, each specimen was prepared longitudinally with burs and subsequently with sandpapers in order to expose the filling materials. Then, the specimens were prepared for scanning electron microscopy analysis. Marginal adaptation was evaluated through scoring of taken micrographs and also measured with Image J software. Human periodontal ligament fibroblasts were cultured for cytotoxicity analysis. MTA, CEM and Biodentine were prepared and after 24 hours they were applied to cells by using Millicell-96 cell culture insert plates for 24, 48 and 72 hours of incubation periods. The effect of materials on cell viability was estimated by WST-1 assay. Data were analyzed with; two-way ANOVA, Bonferroni, Kruskall-Wallis, Mann-Whitney-U, Siegel & Castellan, Spearman correlation coefficient and ANOVA with repeated measures tests. According to the results, no significant difference was found between materials regarding microleakage and marginal adaptation (p>0.05). Significantly higher microleakage and worse marginal adaptation were seen for materials placed in cavities prepared by laser tips compared with those prepared by ultrasonic tips (p0.05). The highest cytotoxicity for Biodentine was seen at 24 hours whereas for MTA and CEM at 72 hours (p0,05). Lazer ile açılan kök ucu kavitelerine yerleştirilen materyallerde, ultrasonik ile açılanlara göre anlamlı olarak daha fazla mikrosızıntı ve daha kötü kenar uyumu görülmüştür (p0,05). En yüksek sitotoksisite Biodentine için 24 saat sonunda, MTA ve CEM için ise 72 saat sonunda görülmüştür (p<0,05). Farklı kök ucu kavite preparasyon tekniklerinin, dolgu materyallerinin mikrosızıntısı ve kenar uyumu üzerine etkisi olduğu görülmüştür. CEM ve Biodentine, MTA ile benzer mikrosızıntı, kenar uyumu ve sitotoksisite sonuçları oluşturmuştur

Effect of Placement Technique on The Push-Out Bond Strength of Calcium-Silicate Based Cements

The purpose of this study was to evaluate the effects of ultrasonic and manual placement techniques on the push-out bond strength of Biodentine and MTA with and without calcium chloride. One hundred and twenty mid-root slices from forty freshly extracted single-rooted human mandibular premolar teeth were instrumented and randomly divided into six groups (n=20) according to the filling material and placement technique applied, as follows: Gl: MTA-manual compaction, G2: Biodentine-manual compaction, G3: MTA+5% CaCl2-manual compaction, G4: MTA-ultrasonic activation, G5: Biodentine-ultrasonic activation, G6: MTA+5% CaCl2 ultrasonic activation. The push-out bond strengths were measured using an Instron testing machine. Data were analyzed using twoway analysis of variance (ANOVA) with Bonferroni correction. The ultrasonic activation significantly enhanced the bond strength values of the materials. Biodentine presented higher bond strength values than that of MTA groups. The addition of CaCl2 to MTA did not improve the bond strength of the material.WoSScopu

Koronal Bariyer Kalınlığının Gelişimi Tamamlanmamış Dişlerin Kırılma Dayanımına Etkisi

Amaç: Rejeneratif endodontik tedavi görmüş vakalarda kök kırıklarının en önemli nedenlerinden biri travmadır. Bu çalışmanın amacı, bariyer materyali olarak farklı kalınlıklarda yerleştirilen Biodentine’in gelişimi tamamlanmamış dişlerin kırılma dayanımına etkisini incelemektir. Gereç ve Yöntem: Gelişimi tamamlanmamış diş simulasyonu için, 65 adet üst santral dişin kök kanalları Peeso reamerlar ile genişletildi. On dişte giriş kavitesi açılmadı ve bunlar negatif kontrol grubu olarak ayrıldı. Giriş kavitesi açılmış 55 dişin, 10 tanesi pozitif kontrol olarak ayrıldı ve bu dişlerin kök kanalına kalsiyum hidroksit yerleştirildi. Kök kanallarına yerleştirilen Biodentine’in kalınlığına göre 45 diş rastgele olacak şekilde 3 gruba ayrıldı (n=15); Grup 1: 2-3 mm kalınlıkta koronal bariyer, Grup 2: 5-6 mm kalınlıkta koronal bariyer, Grup 3: tüm kanalın dolumu. Bekleme süresi sonrası, kırılma dayanımı analizi universal test cihazı ile gerçekleştirildi. Tek yönlü varyans analizi ve Tukey testleri ile istatistiksel analiz yapıldı. Bulgular: Pozitif kontrol, Grup 1 ve Grup 2 arasında anlamlı fark yoktu (P &gt; 0.05). Negatif kontrol ve Grup 3 en yüksek kırılma dayanımı değerlerini gösterdi (P &lt; 0.05) ve bu iki grup arasında anlamlı fark yoktu (P &gt; 0.05). Tüm kırıklar dişlerin servikal kısmında yatay veya eğik olarak meydana geldi. Sonuçlar: Biodentine koronal bariyer olarak kullanıldığında dişlerin kırılma dayanımı üzerinde güçlendirici bir etkisi olmadı. Kök kanalı tamamen Biodentine ile doldurulduğunda en iyi güçlendirme etkisi oluştu. Koronal bariyer kalınlığının gelişimi tamamlanmamış dişlerin kırılma dayanımına herhangi bir etkisi olmadı

TANNİK ASİTLE İRRİGASYONUN KÖK KANAL DENTİNİNİN MİKSROSERTLİĞİNE VE EPOKSİ REZİN ESASLI PATIN BAĞLANMA DAYANIMINA ETKİSİ

Background:To investigate the effects of final irrigation protocols with tannic acid (TA) on dentin microhardness and push-out bond strength of an epoxy resin based sealer to root canal dentin.Methods: The 50 root halves were embedded in an acrylic resin for the microhardness measurement. After the initial baseline microhardness measurement, the root halves were randomly divided into 5 groups according to the final irrigation protocol used (n=10): distilled water (control), 10% TA for 2 min, 10% TA for 5 min, 20% TA for 2 min, and 20% TA for 5 min. After surface treatment, dentin microhardness values were recorded at close proximity to the initial indentation areas. For push-out bond strength test the root canals of 75 single-rooted mandibular premolars were instrumented and the final irrigation protocols were applied as described above (n = 15). Following root canal obturation with single cone technique using matched-taper  gutta percha cones and an AH Plus- epoxy resin based root canal sealer, 1 mm-thick slices were obtained from the middle third of the root canals. Push-out bond strength test was applied. The data were analyzed using One way ANOVA and Tukey HSD tests (p=0.05).Results:In TA-treated groups, there was a significant increase in the microhardness values compared with the control group (p&lt;0.05). Regarding the push-out bond strength test, there was no significant difference between the bond strength values of 10% TA for 2 min and the control group (p&gt;0.05). The remaining groups presented higher bond strength values than the control group (p&lt;0.05).Conclusions: TA increased dentin microhardness and the bond strength of the epoxy resin based sealer to root canal dentin. The effect on the bond strength was time and concentration dependent. Keywords: bond strength, dentin, microhardness, epoxy resin based sealer, tannic aci

Critical evaluation of fracture strength testing for endodontically treated teeth

Objectives The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars. Methods A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs. 6 mm), plunger direction (vertical vs. 135° angular to the central fossa), and PDL simulation. The analysis was conducted using the CosmosWorks structural analysis program, and the results are presented in terms of von Mises stresses. Results The smaller plunger increased the stresses at the contact area of the crown, but the plunger diameter had no effect on the stress distribution within the root. An angular plunger direction increased stresses within the root, as well as at the buccal cusp of the crown, compared with the vertical direction. Simulation of the PDL caused higher stress accumulation, especially in the cervical region of the root. Conclusions The plunger diameter had no effect on the stress distribution in the roots, whereas the plunger direction and PDL simulation did affect the stress distribution. More stringent standards can be established by taking such parameters into account when performing fracture testing in future studies.PubMe

Surface and vertical dimensional changes of mineral trioxide aggregate and biodentine in different environmental conditions

Abstract Surface changes in biological environments are critical for the evaluation of physical and biological activity of biomaterials. Objective: This study investigated surface alterations of calcium silicate-based cements after exposure to different environments. Material and Methods: Forty-eight cylindrical cavities were prepared on root surfaces. The cavities were filled using ProRoot MTA or Biodentine and assigned to four subgroups (n=6): dry, wet, acidic, and blood. Surface topographies were evaluated using an optical profilometer for 28 days, and the roughness of the material surfaces was quantified. Vertical dimensional change was measured by determining the height difference between the material surface and the flat tooth surface. Data were compared with a two-way repeated measures ANOVA and Bonferroni tests. Results: In dry condition, the surface roughness of MTA or Biodentine was constant up to 3 days (p>0.05) but decreased after 28 days (p0.05). Both materials showed the highest roughness in blood conditions on the 1st day (p<0.05), while the surface roughness in blood decreased dramatically after 28 days. The roughness of Biodentine was higher in wet conditions up to 3 days compared with ProRoot MTA (p<0.05). Likewise, in blood condition, Biodentine showed higher roughness on the 28th day than ProRoot MTA (p<0.05). Conclusions: Dry, wet, and blood conditions had a time-dependent effect on the surface roughness and vertical dimensional changes of the materials. However, acidic conditions did not affect the roughness and the surface level of the materials

In Vitro Cytotoxicity Of Calcium Silicate-Based Endodontic Cement As Root-End Filling Materials

The aim of this study was to evaluate the cytotoxicity of three types of calcium silicate-based endodontic cement after different incubation periods with human periodontal ligament fibroblasts. Human periodontal ligament fibroblasts were cultured from extracted third molars and seeded in 96-well plates. MTA, calcium enriched mixture (CEM) cement, and Biodentine were prepared and added to culture insert plates which were immediately placed into 96-well plates containing cultured cells. After incubation periods of 24, 48, and 72 hours, cell viability was determined with WST-1 assay. Data were analysed statistically by ANOVA with repeated measures and Bonferroni tests. There was no significant difference in cell viability amongst the test materials after each incubation period (P > 0.05). MTA and CEM presented more than 90% cell viability after 24 and 48 hours of incubation and showed statistically significant decrease in cell viability after 72 hours of incubation (P < 0.05). Biodentine showed significantly less cell viability (73%) after 24 hours of incubation, whereas more than 90% cell viability was seen after 48 and 72 hours of incubation (P < 0.05). Despite the significant changes in cell viability over time, materials presented similar cytotoxicity profile. Biodentine and CEM can be considered as alternative materials for root-end surgery procedures.PubMedScopu