In Vitro Evaluation of a Ceramicrete-based Root-end Filling Material
Kelvin C.Y. Tay, Bethany A. Loushine, BS, Cindy Oxford, BS, Rishi Kapur, BA, Carolyn M. Primus, PhD, James L. Gutmann, DDS, Robert J. Loushine, DDS, David H. Pashley, DMD, PhD, Franklin R. Tay, BDSc (Hons), PhD
Ceramicrete is an impervious inorganic binder widely used for encapsulating radioactive and hazardous wastes. This study evaluated the feasibility of using a radiopaque Ceramicrete-based material for root-end fillings. Apical seals of root-end preparations filled with Super EBA (Harry J. Bosworth Co, Skokie, IL), White ProRoot MTA (Dentsply Tulsa Dental Specialties, Tulsa, OK), or Ceramicrete-D were evaluated using a computerized fluid filtration approach after the fillings were immersed in phosphate-containing fluid (PCF). The Ceramicrete-D fillings exhibited significantly (P < 0.05) better seals than the other two commercially available, frequently advocated root-end–filling materials. Scanning electron microscopy and x-ray diffraction of Ceramicrete-D after setting revealed a relatively nonporous KMgPO4•6H2O matrix that binds other incompletely reacted and new reaction phases such as CaHPO4•2H2O. Polished dentin slabs filled with Ceramicrete-D and immersed in PCF for 72 hours revealed depositions of acicular-shaped, apatite-like crystallite clusters on the material surface as the pH of the PCF increased with immersion time. The experimental Ceramicrete-based material is potentially bioactive in the presence of PCF.
Effect of Tissue Fluids on Hydrophobicity and Adherence of Enterococcus faecalis to Dentin
Saji George, BSc, MSc, Anil Kishen, BDS, MDS, PhD
This in vitro study was carried out to determine (1) the hydrophobicity of selected oral bacteria, (2) the influence of growth media (saliva and serum) and mode of growth (planktonic or biofilm) on the hydrophobicity of Enterococcus faecalis, and (3) the influence of growth media and conditioning fluids on the adherence of E. faecalis to dentin. The ability to bind to a hydrocarbon phase (xylene) was used as an index of relative hydrophobicity of cells. Fluorescent microscopy–based technique was used to assay the bacterial adherence to dentin. Results showed that bacteria involved in the primary stage of oral biofilm formation such as Streptococcus mutans, Fusobacterium nucleatum, and Porphyromonas gingivalis are relatively more hydrophobic than E. faecalis. The hydrophobicity of E. faecalis was significantly increased during starvation and biofilm mode of growth (p < .05). The adherence of E. faecalis to dentin was appreciably increased after starvation and when dentin was conditioned with saliva. It was observed that surface conditioning of dentin with saliva and starvation can enhance the adherence of E. faecalis to dentin. The findings from this study indicated that the coronal leakage of saliva and the physiologic state of microbes might play an important role in the adherence and biofilm formation of bacteria to root canal dentin.
A Comparative Study of the Effects of Two Nickel–Titanium Preparation Techniques on Root Canal Geometry Assessed by Microcomputed Tomography
Alexios L. Loizides, DDS, MSc, Vasilios D. Kakavetsos, DDS, Giorgos N. Tzanetakis, DDS, Evangelos G. Kontakiotis, DDS, PhD, George Eliades, DDS, PhD
The present study was conducted with the aim of evaluating and comparing the effects of a new Hero group (Endoflare, Hero-shaper, and Hero-apical; Micro-Mega, Besancon, France) and Protaper Ni-Ti rotary instruments (Dentsply/Maillefer, Ballaigues, Switzerland) on root canal geometry in extracted human teeth using microcomputed tomography (μCT). Twenty-two mesial root canals of mandibular first molars were randomly divided into two groups. Canals were scanned before and after preparation with both systems. Cross-sectional images of each canal were obtained at 2-mm intervals. Differences in canal roundness, cross-sectional area, perimeter of each canal before and after instrumentation, and the extent of root canal transportation were calculated using image analysis software. There was no difference between the two rotary systems in regards to working time. Both systems create a similar round shape after instrumentation regardless of the initial root canal’s shape. The Hero instruments showed a greater cutting efficiency compared with the ProTaper at the levels of 8 mm, 6 mm, and 4 mm but not at the level of 2 mm. On the other hand, the ProTaper seems to have a similar cutting efficiency at all levels. However, the ProTaper showed a tendency toward apical transportation. Under the conditions of the present study, both preparation techniques prepared the canals rapidly with a sufficient round shape. Despite that, it seems that there is a great potential for the improvement of shaping ability of rotary instruments. Hybrid instrumentation techniques should be evaluated by future studies in order to provide better results regarding the shaping ability of rotary instruments.
Inferior Alveolar Nerve Damage Because of Overextended Endodontic Material: A Problem of Sealer Cement Biocompatibility?
Jaume Escoda-Francoli, DDS, Carles Canalda-Sahli, MD, DD, PhD, Albert Soler, PhD, Rui Figueiredo, DDS, Cosme Gay-Escoda, MD, DDS, PhD
Damage to the inferior alveolar nerve is a relatively infrequent complication in dental practice. When root canal treatment of a lower molar or premolar surpasses and/or overextends beyond the apical foramen and invades the periapical zone, the foreign material introduced within such a sensitive anatomical space may mechanically or even chemically affect the inferior alveolar nerve. We describe a case of endodontic treatment of a permanent right lower first molar in which the sealer cement overextended in large amounts and damaged the right inferior alveolar nerve. The condition reverted a few months after the surgical removal of the material. Evaluation of the removed material, using powder x-ray diffraction and scanning electron microscopy with coupled dispersive energy spectroscopy, showed it to consist of calcium tungstate (scheelite [CaWO4]) and zirconium oxide (baddeleyite [ZrO2]), which were chemical components of the sealer cement.
Influence of Previous Angular Deformation on Flexural Fatigue Resistance of K3 Nickel–Titanium Rotary Instruments
Fabiola Ormiga Galvão Barbosa, MSc, José Antônio da Cunha Ponciano Gomes, MSc, Marcos Cesar Pimenta de Araújo, DSc
Several studies have evaluated the influence of torsion and bending loads on the mechanical resistance of nickel-titanium instruments. The aim of the present study was to analyze the influence of previous angular deformation on K3 files resistance to flexural fatigue. New files and files previously submitted to different angular deformation were tested for flexural fatigue, and the number of cycles to fracture was compared. The results indicated that as the angular deformation increases, the number of cycles attained under flexural fatigue condition decreases. A reduction of fatigue resistance was registered even when a significant plastic deformation was not imposed. From the obtained results, it may be suggested that the sequential loading, including torsion and flexural fatigue, can be responsible for instrument separation during clinical practice. Successive torsion overloads, occurring together with flexural fatigue, reduce the mechanical resistance of nickel-titanium files.
In Vitro Evaluation of the Cleansing Working Time and Analysis of the Amount of Gutta-Percha or Resilon Remnants in the Root Canal Walls after Instrumentation for Endodontic Retreatment
Rodrigo Sanches Cunha, PhD, Alexandre Sigrist De Martin, PhD, Pedro Paulo Barros, PhD, Fabiola Mendonça da Silva, PhD, Rogério de Castilho Jacinto, PhD, Carlos Eduardo da Silveira Bueno, PhD
The present study assessed the obturation removal and reinstrumentation working time of canals filled with Resilon/Real Seal in comparison with canals filled with gutta-percha/AH Plus. Thirty human extracted canines were instrumented. In group 1 (n = 15) root canals were filled with Resilon/Real Seal and in group 2 (n = 15) with gutta-percha/AH Plus sealer. The obturations were removed from both by using chloroform and irrigation with 2.5% NaOCl, and the canals were manually reinstrumented. The teeth were radiographically analyzed. Specimens without obturation material remnants visible in the radiographic examination were selected for analysis under scanning electron microscopy. The Resilon/Real Seal system was removed in greater quantities from the canal walls compared with the gutta-percha cones and the AH Plus cement. Time was not a significant factor. Under scanning electron microscopy analysis, the teeth presented material remnants in the 3 analyzed thirds. Resilon was better removed from the canal than the gutta-percha cones and the AH Plus.
Disinfection of Dentinal Tubules with 2% Chlorhexidine, 2% Metronidazole, Bioactive Glass when Compared with Calcium Hydroxide as Intracanal Medicaments
Jogikalmat Krithikadatta, MDS, Rajamani Indira, MDS, Alfred Leo Dorothykalyani, MSc
Thorough disinfection of the root canal system is essential for the success of root canal therapy. This requires the use of an intra-canal medicament. Enterococcus faecalis is the most frequently found species in persistent/secondary intracanal infection associated endodontic treatment failure. This study evaluates the disinfection of dentinal tubules using 2% chlorhexidine gel, 2% metronidazole gel, bioactive glass (S53P4) in comparison with calcium hydroxide. The antibacterial efficacy of the four medicaments against Enterococcus faecalis was assessed in vitro using extracted premolar teeth at the depths of 200 μm and 400 μm. The overall percentage inhibition of bacterial growth (at 200 μm and 400 μm depth) was 100% with 2% chlorhexidine gel. The inhibition of growth was moderate with 2% metronidazole gel (86.5%), followed by bioactive glass (62.8%) and calcium hydroxide (58.5%). It can be concluded from the present study that 2% chlorhexidine gel alone was most effective against E. faecalis when compared to other medicaments tested.
An In Vitro Comparison of Microleakage between Resilon and Gutta-Percha with a Fluid Filtration Model
Jaron R. Wedding, DDS, MSD, Cecil E. Brown, DDS, MS, Joseph J. Legan, DDS, MS, B. Keith Moore, PhD, Mychel M. Vail, DDS, MSD
This investigation compared microleakage of teeth obturated with gutta-percha and teeth obturated with Resilon by using a fluid filtration model. Forty-six human, single-rooted, mandibular premolars were studied. Teeth were randomly assigned to 2 experimental groups of 21 teeth each, designated as group G (gutta-percha) and group R (Resilon). Two control groups, both containing 2 teeth, served as positive and negative controls. Group G, gutta-percha and AH 26 sealer, and group R, Resilon and Epiphany sealer, were obturated by using warm vertical condensation. The specimens were tested for microleakage with an in vitro fluid filtration apparatus at 10 psi at 4 intervals: 1, 7, 30, and 90 days. A two-way repeated measures analysis of variance model with fixed effects for group, time, and group by time interaction was used to analyze microleakage data. This study demonstrated that canals obturated with Resilon and Epiphany sealer leaked statistically less than canals obturated with gutta-percha and AH 26 sealer at day 1 (P < .0014), day 7 (P < .0002), day 30 (P < .0015), and day 90 (P < .0170). The mean fluid microleakage for both group G and group R increased from day 1 to day 90. The results showed that Resilon is a suitable replacement for gutta-percha as a root canal filling material on the basis of its increased resistance to fluid microleakage.
A Six-Year Evaluation of Cracked Teeth Diagnosed with Reversible Pulpitis: Treatment and Prognosis
Keith V. Krell, DDS, MS, MA, Eric M. Rivera, DDS, MS
The purpose of this investigation was to report on the clinical outcomes of cracked teeth diagnosed with reversible pulpitis (RP). Eight thousand one hundred seventy-five patients referred for evaluation and treatment during a 6-year period had medical and dental histories, radiographs, pulpal and periapical diagnosis, periodontal probings, direct identification of crack(s) with transillumination, and biting responses on various cusps recorded. All data were stored daily in a database. All cases were treatment planned according to the pulpal and periapical diagnosis. Cases with RP were treatment planned for crowns only, regardless of periapical diagnosis. All patients were recalled at 1 year unless root canal treatment was needed before the anniversary. Results indicated that cracks were identified in 9.7% (796 of 8175) of all teeth evaluated during this time period. Of 127 patients specifically diagnosed with RP, 27 converted to irreversible pulpitis (N = 21) in 58 days or to necrotic pulp (N = 6) in 149 days. To date, none of the original remaining 100 cases of RP have required root canal treatment. The outcomes of this study suggest that if a marginal ridge crack is identified early enough in teeth with a diagnosis of RP and a crown is placed, root canal treatment will be necessary in about 20% of these cases within a 6-month period.
Assessment of the Deviation after Biomechanical Preparation of the Coronal, Middle, and Apical Thirds of Root Canals Instrumented with Three HERO Rotary Systems
Andréa Cruz Câmara, BDS, MSc, Carlos Menezes Aguiar, BDS, MSc, PhD, Jose Antonio Poli de Figueiredo, BDS, MSc, PhD
The aim of the present study was to assess the risk of deviation of the root canals prepared by 3 HERO rotary systems, used solely or in association, by means of preoperative and postoperative imaging of a cross-section of their coronal, middle, and apical thirds. Fifty mesiobuccal canals of human first molars were randomly divided into 5 groups of 10 specimens each: group A, HERO 642; group B, HERO 642 + HERO Apical; group C, HERO Shaper; group D, HERO Shaper + HERO Apical; group E (control), NitiFlex files. Fisher exact test showed that the differences between the percentages of the presence of deviation and the differences observed between the proportions of instrumented and noninstrumented walls were not statistically significant. No system presented absolute effectiveness, because each of them produced morphologic changes and failed to instrument all the walls of the root canals. A level of significance of .05 was adopted.
The Correlation between Serum Immunoglobulin A and Immunoglobulin G Levels and the Presence of Treponema denticola in Human Periapical Lesions
Dilsah Cogulu, DDS, PhD, Ozant Oncag, DDS, PhD, Necil Kutukculer, MD, Atac Uzel, PhD, Cemal Eronat, DDS, PhD
The aim of this study was to compare the serum immunoglobulin A (IgA) and immunoglobulin G (IgG) levels and the presence of Treponema denticola in the root canals in a group of teeth with/without periapical lesion. A total of 66 children aged 8 to 13 years old were involved in this study. Five milliliters of blood samples were taken to detect the serum IgA and IgG levels. Sixty-six endodontic samplings were also obtained to determine the presence of T. denticola by polymerase chain reaction. The presence of T. denticola between the groups with/without periapical lesion was statistically significant (p = 0.026). A significant negative correlation was found between serum IgG and IgA levels and the presence of T. denticola (p = 0.023 and 0.038, respectively). This study may support the hypothesis that the presence of T. denticola in the root canals is mainly related to the periapical lesions, and the higher levels of serum IgG and IgA levels may protect against T. denticola.
Bacterial DNA Persists for Extended Periods after Cell Death
Geoffrey Young, BDS, Sally Turner, BSc, PhD, John K. Davies, BSc, PhD, Göran Sundqvist, DDS, PhD, David Figdor, MDSc, FRACDS, DipEndo, PhD, FASM
The fate of DNA from bacteria that infect the root canal but cannot survive is currently unknown, yet such information is essential in establishing the validity of polymerase chain reaction (PCR)–based identification methods for root canal samples. This in vitro study tested the hypothesis that PCR-detectable DNA from dead bacteria might persist after cell death and investigated the efficiency of sodium hypochlorite (NaOCl) as a field decontamination agent. Using heat-killed Enterococcus faecalis, the persistence of DNA encoding the 16S rRNA gene was monitored by PCR. While most probable number analysis showed an approximate 1000-fold decay in amplifiable template, E. faecalis DNA was still PCR-detectable 1 year after cell death. NaOCl (1%) eliminated amplifiable DNA within 60 seconds of exposure. Our findings also disclosed a previously overlooked problem of concentration-dependent inhibition of the PCR reaction by thiosulfate-inactivated NaOCl. These results highlight the challenges of reliably identifying the authentic living root canal flora with PCR techniques.
Cyclic Fatigue of EndoSequence and K3 Rotary Files in a Dynamic Model
Jarom J. Ray, Timothy C. Kirkpatrick, Richard E. Rutledge
The cyclic fatigue resistance of K3 and EndoSequence files was compared by rotating files against a highly polished surface inclined at 15 degrees to the horizontal. For each brand, files with a 25 tip in .04 and .06 taper and files with a 40 tip in .04 and .06 taper were tested at both 300 and 600 rpm. A 3-mm axial movement simulated a clinical pecking motion at 1 cycle per second. The number of rotations to failure was calculated and analyzed by using analysis of variance and Independent Student’s t tests, with results confirmed by nonparametric Mann-Whitney U tests with a Bonferroni correction. At both 300 and 600 rpm, K3 files exhibited statistically significantly more cycles to fracture than their EndoSequence counterparts with the same tip size and taper. Scanning electron microscopy images demonstrated surface features consistent with fracture due to cyclic fatigue. In this model, file design appeared to be the most important determinant of cyclic fatigue resistance.
Regional Push-out Bond Strength and Coronal Microleakage of Resilon after Different Light-curing Methods
Emre Nagas, DDS, Zafer C. Cehreli, DDS, PhD, Veli Durmaz, DDS, PhD, Pekka K. Vallittu, DDS, PhD, Lippo V.J. Lassila, DDS, MSc Eng
The purpose of this study was to assess the push-out bond strength and coronal microleakage of the Epiphany (Pentron Clinical Technologies, Wallingford, CT) + Resilon (Resilon Research LLC, Madison, CT) obturation system with respect to different photoactivation methods used. Roots of human maxillary central incisors (n = 60) were prepared with 0.06 taper nickel-titanum rotary files to size 30. After application of the Epiphany sealer, the roots were obturated with Resilon cones. The specimens were randomly assigned into three groups (n = 10/group) according to the light-curing unit (LCU) used from the coronal aspect: (1) quartz-tungsten-halogen/40 seconds, (2) light-emitting diode/20 seconds, and (3) plasma arc/6 seconds. Thereafter, 2-mm thick horizontal sections (n = 3) were obtained from each specimen from the coronal to apical direction and subjected to push-out test at a crosshead-speed of 1mm/min. Failure modes were assessed quantitatively under a stereomicroscope and morphologically under a scanning electron microscope. The remaining 30 roots were used for the dye-leakage assessments. Both the type of LCU and the level of sectioning had significant effects on bond strength. The following statistical ranking was obtained for bond strength values: quartz-tungsten-halogen > light-emitting diode > plasma arc. Coronal microleakage of specimens cured with the plasma arc was significantly greater than those of other groups (p < 0.05).
Vascular Endothelial Growth Factor Receptor–2 Expression in the Pulp of Human Primary and Young Permanent Teeth
Leticia Grando Mattuella, DDS, MSc, José Antonio Poli de Figueiredo, DDS, MSc, PhD, Jacques E. Nör, DDS, MSc, PhD, Fernando Borba de Araujo, DDS, MSc, PhD, Anna Christina Medeiros Fossati, DDS, MSc, PhD
The purpose of this study was to evaluate the expression of vascular endothelial growth factor receptor–2 (VEGFR-2) in endothelial cells within the dental pulp of human primary and young permanent teeth and the spatial distribution of VEGFR-2–positive cells. Nine sound primary teeth and 4 sound young permanent teeth were evaluated by immunohistochemistry with a human anti–VEGFR-2 antibody. Stained tissue sections were analyzed qualitatively under light microscopy. Here we observed that endothelial cells of both primary and permanent teeth showed positive immunostaining for VEGFR-2. Notably, VEGFR-2–positive cells in the primary teeth tended to be found close to the subodontoblastic layer, whereas the spatial distribution of VEGFR-2 immunostaining in the permanent teeth was more uniform. In conclusion, VEGFR-2 was expressed in the microvascular endothelial cells of both primary and young permanent teeth, which suggests that these cells are capable of responding to the morphogenetic and survival signals mediated by VEGF.
Sealing Ability of White and Gray Mineral Trioxide Aggregate Mixed with Distilled Water and 0.12% Chlorhexidine Gluconate When Used as Root-end Filling Materials
Shahriar Shahi, DDS, MSc, Saeed Rahimi, DDS, MSc, Hamid Reza Yavari, DDS, MSc, Sahar Shakouie, DDS, MSc, Saeed Nezafati, DDS, MSc, Majid Abdolrahimi, DDS
This in vitro study used dye penetration to compare the sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate when used as root-end filling materials. Ninety-six single-rooted human teeth were cleaned, shaped, and obturated with gutta-percha and AH26 root canal sealer. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The teeth were randomly divided into 4 experimental groups, each containing 20 teeth, and 2 negative and positive control groups, each containing 8 teeth. Root-end cavities in the experimental groups were filled with the experimental materials. After decoronation of the teeth and application of nail polish, the teeth were exposed to India ink for 72 hours and longitudinally sectioned, and the extent of dye penetration was measured with a stereomicroscope. Statistical analysis showed that there were no significant differences among the 4 experimental groups.
Apical Accuracy of Two Apex-locating Handpieces in Root Canal Retreatments of Root-end Resected Teeth
Özgür Uzun, DDS, PhD, Özgür Topuz, DDS, PhD, A. Cemal Tinaz, DDS, PhD, Tayfun Alaçam
We aimed to evaluate the accuracy of 2 apex locator integrated endodontic motors during retreatment of root-end resected teeth by using 40 extracted incisor teeth. The apical 3 mm of the roots were resected, and the root lengths were recorded as resected length of the roots. Forty roots were randomly divided into 2 groups of 20 to evaluate the 2 handpieces, Tri Auto ZX and TCM Endo V. The working lengths measured during the auto reverse function and during the electronic apex locator function with Tri Auto ZX and TCM Endo V were recorded and compared with resected length of the roots. The repeated measures analysis of variance was used for statistical analyses. Electronic apex locator functions of both devices might be used for apical accuracy, but the auto reverse functions might not be useful to 0.0-mm accuracy in retreatment procedures of root-end resected teeth.
Mandibular First Molar with Four Distal Canals
Jamileh Ghoddusi, DDS, MSc, Neda Naghavi, DDS, MSc, Mina Zarei, DDS, MSc, Ehsan Rohani, DDS
A mandibular first molar with more than four canals is an interesting example of anatomic variations, especially when four of these canals are located in distal roots. This report describes a case of a mandibular first molar with six canals (two mesial and four distal canals in two distal roots). The canals were equipped with a K-file and irrigated with NaOCl (5.25%) and normal saline as the final irrigant. The canals were filled laterally with gutta percha and AH26 sealer (De Trey, Dentsply, Switzerland). This case shows a rare anatomic configuration and points out the importance of looking for additional canals.
Effect of Environment on Low-cycle Fatigue of a Nickel–Titanium Instrument
Gary S.P. Cheung, MDS, MSc, PhD, Ya Shen, BDS, PhD, Brian W. Darvell, PhD, DSc
This study examined the low-cycle fatigue (LCF) behavior of a nickel-titanium (NiTi) engine-file under various environmental conditions. One brand of NiTi instrument was subjected to rotational-bending fatigue in air, deionized water, sodium hypochlorite, or silicone oil. The curvature of each instrument, diameter of the fracture cross-section, and the number of rotations to failure were determined. The strain-life relationship in the LCF region was examined by using one-way analysis of variance, and the number of crack origins with χ2, for differences between groups. The results showed a linear relationship, on logarithmic scales, between the LCF life and the surface strain amplitude; regression line slopes were significantly different between noncorrosive (air, silicone oil) and corrosive (water, hypochlorite) environments (P < .05), as well as number of crack origins (P < .05). Hypochlorite was more detrimental to fatigue life than water. In conclusion, environmental conditions significantly affect the LCF behavior of NiTi rotary instruments. Fatigue testing of NiTi engine-files should be in a service-like environment.
Cytotoxic Effects of Four Different Endodontic Materials in Human Periodontal Ligament Fibroblasts
Melahat Gorduysus, DDS, Nihal Avcu, DDS, Omer Gorduysus, DDS, Aysel Pekel, MsC, Yusuf Baran, PhD, Ferit Avcu, MD, Ali Ugur Ural, MD
The purpose of this study was to compare the cytotoxicity, induced apoptosis and/or necrosis, and apoptotic mechanisms in human periodontal ligament (PDL) fibroblasts treated with four different endodontic materials: White ProRoot mineral trioxide aggregate (MTA) (MTA/Dentsply; Tulsa Dental, Memphis, TN), Diaket (ESPE, Seefeld, Germany), Endion (VOCO, Cuxhaven, Germany), and CYMED 8410 (NANO, Kaohsiung, Taiwan). The effects of these four materials on the viability of PDL fibroblasts were determined by MTT (3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-SH-tetrazolium bromide) assay. Apoptotic pathways were evaluated via several mechanisms. Exposure to MTA for 24, 48, and 72 hours resulted in no significant differences in MTT reduction and viable cell number compared with controls. However, treatment of PDL fibroblasts with Diaket, Endion, and CYMED 8410 for 24, 48, and 72 hours resulted in cytotoxicity with MTT and a reduction of viable cell number with trypan blue dye exclusion test compared with controls (from p < 0.05 to p < 0.001). Annexin V-FITC/PI staining showed that Diaket, Endion, and CYMED 8410 induced higher percentages of apoptosis and/or necrosis than in controls (45.6%, 25.5%, and 6.3%, respectively). Results of cell-cycle analyses were concordant with annexin V-FITC/PI staining findings. These results suggest that MTA is a very biocompatible filling material. However, Diaket, Endion, and CYMED 8410 are toxic to PDL fibroblasts in vitro. The main form of cell death induced by these filling materials was determined to be apoptosis and/or necrosis.