Mehmet Burak Guneser

Effect of Various Endodontic Irrigants on the Push-out Bond Strength of Biodentine and Conventional Root Perforation Repair Materials

INTRODUCTION The aim of this study was to evaluate the effect of various endodontic irrigants on the push-out bond strength of Biodentine (Septodont, Saint Maur des Fossés, France) in comparison with contemporary root perforation repair materials. METHODS Midroot dentin of canine teeth was horizontally sectioned into 1-mm-thick slices. The canal space of each dentin slice was enlarged with a diamond bur to 1.4 mm in diameter. The samples were divided into 5 groups (n = 40), and the following materials were placed, respectively: Biodentine, ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), amalgam, Dyract AP (Dentsply DeTrey, Konstanz, Germany), and intermediate restorative material (IRM, Dentsply DeTrey). The samples were wrapped in wet gauze for 10 minutes and divided into 3 subgroups (n = 10) to be immersed into 3.5% sodium hypochlorite, 2% chlorhexidine gluconate (CHX), or saline for 30 minutes. No irrigation was performed in the controls (n = 10), and a wet cotton pellet was placed over each test material. After incubation for 48 hours, the dislodgement resistance of the samples was measured using a universal testing machine. The samples were examined under a stereomicroscope to determine the nature of the bond failures. RESULTS Biodentine showed significantly higher push-out bond strength than MTA (P < .05). The statistical ranking of push-out bond strength values was as follows: Dyract AP > amalgam ≥ IRM ≥ Biodentine > MTA. The push-out bond strength of Dyract AP, amalgam, IRM, and Biodentine was not significantly different when immersed in NaOCl, CHX, and saline solutions, whereas MTA lost strength when exposed to CHX. CONCLUSIONS Biodentine showed considerable performance as a perforation repair material even after being exposed to various endodontic irrigants, whereas MTA had the lowest push-out bond strength to root dentin.

Tissue Dissolution Ability of Sodium Hypochlorite Activated by Photon-initiated Photoacoustic Streaming Technique

INTRODUCTION The aim of this study was to evaluate the effect of the photon-initiated photoacoustic streaming (PIPS) technique on the pulp tissue-dissolving capacity of sodium hypochlorite (NaOCl) and compare it with the EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK) and the Er:YAG laser with an endodontic fiber tip. METHODS Bovine pulp tissue samples (45 ± 15 mg) and dentin powder (10 mg) were placed in 1.5-mL Eppendorf tubes with 1 mL 5.25% NaOCl (Wizard; Rehber Kimya, Istanbul, Turkey) or distilled water (control) for 5 minutes with activation by the EndoActivator System, the Er:YAG laser with an endodontic fiber tip, and the PIPS technique. Nonactivated NaOCl served as the positive control. All testing procedures were performed at room temperature. The tissue samples were weighed before and after treatment, and the percentage of weight loss was calculated. The differences were statistically analyzed. RESULTS The highest rate of tissue dissolution was observed in the NaOCl + Er:YAG group (P < .05). The NaOCl + PIPS group dissolved more bovine pulp tissue than the nonactivated NaOCl group (P < .05). There was no statistically significant difference between the rates of tissue dissolution of the NaOCl + EA and the nonactivated NaOCl groups (P > .05). CONCLUSIONS NaOCl activation with the Er:YAG laser with an endodontic fiber tip was the most effective in bovine pulp tissue dissolution. The PIPS technique also promoted superior tissue-dissolving effects when compared with no activation. However, the EndoActivator System had no direct effect on tissue dissolution.

Fracture resistance of roots obturated with a novel calcium silicate-based endodontic sealer (BioRoot RCS)

Abstract The aim of this ex vivo study was to evaluate the vertical-fracture resistance of roots obturated with a newly developed tricalcium silicate cement (BioRoot RCS; Septodont, Saint Maur Des Fosses, France) using cold lateral compaction technique (LC) or matched-taper single-cone gutta-percha technique (SC). Decoronated 82 single-rooted mandibular premolars were chemo-mechanically prepared and then randomly divided into 6 experimental groups (n = 12) and 2 control groups (n = 5): Group 1 iRoot SP-LC; Group 2 iRoot SP-SC; Group 3 MTA Fillapex-LC; Group 4 MTA Fillapex-SC; Group 5 BioRoot RCS-LC and Group 6 BioRoot RCS-SC. In the positive-control group, roots were instrumented but not filled, and in the negative-control group, roots were neither instrumented nor filled. All samples were incubated for two weeks and then subjected to vertical loading force (1 mm/min) until fracture. The force required to fracture each specimen were determined, and the data were statistically analyzed. The highest significant fracture resistance was recorded for the iRoot SP-LC, iRoot SP-SC, BioRoot RCS-LC, and BioRoot RCS-SC groups, with no significant difference among them (p > 0.05) when compared with the positive-control group (p < 0.05), whereas the lowest significant values were observed in the MTA Fillapex-LC and MTA Fillapex-SC groups (p < 0.05). The vertical fracture resistance of roots obturated with BioRoot RCS and iRoot SP sealers using either LC or SC technique was found to be similar to that of intact teeth. BioRoot RCS, newly developed tricalcium silicate cement, might have the potential to reinforce the instrumented teeth against vertical root fracture.

Are dentin posts biomechanically intensive?: A laboratory and FEA study

The goal of this laboratory and finite elemental stress analysis (FEA) study was to compare fracture strength of dentin post (DP) with stainless steel and glass fiber posts. Single-rooted teeth were decoronated and restored with ParaPost (PP), i-TFC (TFC), and DPs (n = 10). Resin cores were created and loaded until failure (1.0 mm/min). The data were analyzed (ANOVA, Tukey, Chi-Square tests). Three-dimensional FEA models of the posts were created and the stress distributions were calculated using Solid Works/Cosmos works structural analysis program. A significant difference was found among the groups (p < 0.001). TFC group showed the highest and the DP group showed the lowest fracture resistance (p < 0.001). PP created more stress at the root dentin and inside the post. Restoration of roots with glass fiber and DPs may reduce stresses within the core material and the remaining root. However, a fracture-resistant restoration cannot be achieved by using a DP.

Evaluation of C. Albicans and S. Mutans adherence on different provisional crown materials

PURPOSE Bacterial adhesion on provisional crown materials retained for a long time can influence the duration for which permanent prosthetic restorations can be healthily worn in the oral cavity. The aim of this study was to compare seven different commonly used provisional crown materials with regard to Streptococcus mutans and Candida albicans surface adhesion. MATERIALS AND METHODS For each group, twenty specimens of the provisional fixed prosthodontic materials TemDent (Schütz), Imıdent (Imıcryl), Tab 2000 (Kerr), Structur Premium (Voco), Systemp (Ivoclar Vivadent), Acrytemp (Zhermack), and Takilon-BBF (Takilon) were prepared (diameter, 10.0 mm; height, 2.0 mm). Surface roughness was assessed by atomic force microscopy. Each group was then divided into 2 subgroups (n=10) according to the microbial suspensions used: S. mutans and C. albicans. The specimens were incubated at 37℃ with S. mutans or C. albicans for seven days. Bacterial adherence on surfaces was assessed using the 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) assay. RESULTS S. mutans showed maximum adhesion to Structur, followed by Systemp, Acrytemp, Takilon, Tab 2000, Imident, and TemDent (P<.05). The highest vital C. albicans adhesion was noted on Takilon, followed by Imident and Tab 2000; the lowest adhesion was noted on Systemp (P<.05). CONCLUSION The materials showed significant differences in the degree of bacterial adhesion. C. albicans showed higher surface adhesion than S. mutans on provisional crown and fixed partial denture denture materials.

Çeşitli Antiseptik Taşıyıcılarla Karıştırılan Kalsiyum Hidroksitin Enterococcus faecalis üzerindeki Antimikrobiyal Etkinliği

Amac: Bu in vitro calismanin amaci farkli antiseptik tasiyici - kalsiyum hidroksit (KH) kombinasyonlarinin Enterococcus faecalis (E. faecalis) ile enfekte kok kanallarindaki antibakteriyel etkinligini dentin blok modeli kullanarak test etmektir. Gerec ve Yontemler: Altmis adet cekilmis insan disi ornekleri hazirlandi. Elli-bes tane kok segmenti E. faecalis ile 2 hafta boyunca enfekte edildi. Ornekler 5 deney grubuna ayrildi (n=10) ve su KH – antiseptik tasiyici karisimlari uygulandi: Grup 1, KH + gliserin - distile su (7:1); Grup 2, KH + Octenisept; Grup 3, KH + %2’lik klorheksidin glukonat (CHX); Grup 4, KH + Savlex; Grup 5, KH + %5.25’lik sodyum hipoklorit (NaOCl). Antiseptik-KH karisimlari 7 gun boyunca kok kanallarinda bekletildi. Bes ornek sterilligi kontrol etmek icin (negatif kontrol), bes ornek de pozitif kontrol olarak kullanildi. Gates glidden frezler (# 3, 4, 5) yardimiyla kanal duvarlarindan elde edilen dentin ornekleri fosfat-tamponlu salin (PBS) ve cam boncuk iceren siselere aktarildi ve 30 sn vortekslendi. Bakteri iceren PBS’ye seri dilusyon yapildi. Her bir dilusyondan 25 μL halinde damlalar tripton soya agar plaklari uzerine ekildi ve 37°C’de 48 saat inkube edildi. Gorunur koloni sayilari incelendi ve log10 degerlerine donusturuldu. Istatistiksel analiz icin Kruskal-Wallis ve Mann Whitney-U testleri kullanildi. Bulgular: Negatif kontrol grubunda bakteri uremesi gorulmezken pozitif kontrol grubunun butun orneklerinde bakteri uremesi gozlemlenmistir (log10 3,47 CFU ml-1). Deney gruplari arasinda istatistiksel olarak anlamli bir fark bulunmamistir (p>0.05). KH + CHX ve KH + Savlex gruplarinda E. faecalis biyofilmi tamamen elimine edilmistir. Sonuc: Savlex, Octenisept ve NaOCl gibi cesitli antiseptik ajanlar KH ile karistirilarak kullanildiginda kok kanallarindan E. faecalis’i elimine etmede etkili bulunmustur.

Tooth discoloration effects of calcium silicate based barrier materials used in revascularization and treatment with internal bleaching

Background/purpose Usage of barrier materials is an important step in revascularization procedure. One of the undesired properties of these barrier materials is to cause coronal tooth discoloration. The aim of this in vitro study was to evaluate the tooth discoloration induced by ProRoot MTA (PMTA), Biodentine, and MM-MTA, as well as the efficacy of internal bleaching on this discoloration. Materials and methods Forty-two maxillary incisor teeth were prepared. Triple antibiotic paste (TAP) was placed in the root canals and incubated for 3 weeks. After removing the TAP, blood embedded spongostans were inserted into the root canals, and PMTA, Biodentine, or MM-MTA was placed over them. The teeth were incubated for 4 weeks at 37 °C; then, the internal bleaching agent was sealed for one week. The tooth color was measured throughout the study and the color change values (ΔE) of each specimen were calculated, and the data was statistically analyzed using the one-way ANOVA and Tamhanes T2 tests. Results The TAP significantly decreased the luminosity of the teeth (p < 0.05); however, no significant differences were observed between the tooth discolorations induced by the PMTA, Biodentine, and MM-MTA (p > 0.05). The teeth in the Biodentine group were more whitened than those of the PMTA and MM-MTA groups (p < 0.05). Conclusion Although the PMTA, Biodentine, and MM-MTA caused similar color alterations in the teeth, more bleaching was observed on those teeth discolored using TAP + blood + Biodentine.

Evaluation of antibacterial effects of contemporary orthodontic bonding materials

Abstract Aim: The aim of this study was to evaluate the antibacterial effects of five orthodontic bonding materials commonly used in orthodontics. Materials and Methods: The antibacterial effects of five orthodontic bonding materials were evaluated against Streptococcus mutans and Streptococcus salivarius by direct contact test (DCT). Using the DCT technique, quintet specimens of Transbond XT, Blugloo, Grengloo, Light Bond, and Opal Bond were applied to the bottom and the walls of the five wells of a 96-microtiter plate with a height of 2 mm. Samples were prepared in two sets: 1-day samples and 7-day samples. Ten microliters of bacterial suspension were added to each well for direct contact with each material for 1h at 37 °C. Bacterial growth was then measured in a microplate spectrophotometer hourly at 600 nm for 24 h. Five uncoated wells with identical inoculum sizes served as positive controls. The data obtained at the end of 24 h was statistically analyzed with one-way ANOVA, and post hoc comparisons were done using Tamhane’s T2 test. Results: Blugloo generally showed better antibacterial activity than the other materials. Transbond XT did not show any antibacterial activity. There was a statistically significant difference between Transbond XT and Light Bond in the 1-day sample against S. mutans (p < 0.05). No statistically significant differences were found among the other groups (p > 0.05). Conclusion: Blugloo had the most potent antibacterial activity against S. salivarious.

Effect of intracanal medicaments on the push-out bond strength of Biodentine in comparison with Bioaggregate apical plugs

Abstract To evaluate the effect of intracanal medicaments on the push-out bond strength of Biodentine in comparison with DiaRoot BioAggregate (BA) when used as apical plugs. Forty single-rooted teeth were prepared using Peeso reamers. The samples were divided into four groups. The intracanal medicaments were applied to the root canals as follows: Group1: a combination of metronidazole–ciprofloxacin–cefaclor, Group2: a combination of metronidazole–ciprofloxacin, Group3: calcium hydroxide, and Group4: no medication. After 21 days, the medicaments were removed. The apical part of each root was horizontally sectioned into 1-mm thick slices. The samples were divided into two subgroups, and the following materials were placed: Biodentine, DiaRoot-BioAggregate. After 48-h incubation, the push-out bond strength was measured. The data were analyzed by a two-way ANOVA. Biodentine showed a significantly higher mean push-out bond strength value than DiaRoot-BioAggregate (P = 0.00). The medications have an effect on the push-out bond strength of both materials (P = 0.002). Biodentine showed better adhesive performance as an apical plug than DiaRoot-BioAggregate.

The effect of gelatinase production of Enterococcus faecalis on adhesion to dentin after irrigation with various endodontic irrigants

Abstract Objectives: The aim of this study was to evaluate whether the gelatinase production ability of Enterococcus faecalis provides any advantage on adhesion of this bacterium to dentin treated with various irrigants and their combinations. Materials and methods: Standardized dentin discs were randomly divided into five groups (n = 20): group 1: 2.5% sodium hypochlorite (NaOCl), group 2: 2% chlorhexidine (CHX), group 3: NaOCl + Saline + CHX, group 4: NaOCl + EDTA + NaOCl, group 5: QMix. After incubation of dentin discs with irrigants, each group was divided into two subgroups (n = 10) according to the bacterial strains used; a gelatinase-producing and a gelatinase-deficient strain of E. faecalis. After incubation of the discs with the bacterial suspensions aerobically for 48 h, XTT assay was conducted for bacterial adherence evaluation. Data were statistically analyzed by ANOVA and Tukey’s HSD tests (p = .05). Results: Gelatinase-producing E. faecalis adhered to dentin was significantly more than gelatinase-deficient E. faecalis in all test groups (p < .05). Adherence to CHX-treated dentin was lower than to the surfaces treated with other irrigants, alone or in combination (p < .05). These differences were significant except for comparisons with QMix for gelatinase-producing bacteria (p < .05). Conclusions: Gelatinase production of E. faecalis may be an important factor for bacterial adhesion. The addition of CHX to the irrigation regimen resulted in fewer adhered bacteria to dentin. QMix was not as effective as CHX in terms of bacterial adhesion prevention.