A Comparative Evaluation of the Cleaning Efficacy of Five Different Root Canal Irrigation Devices: A Histological Study.

OBJECTIVES: This study is aimed to evaluate the cleaning efficacy of five different irrigation systems as SonicMax, RinsEndo, EndoVac, passive ultrasonic irrigation (PUI), and manual needle irrigation (MNI) to histologically evaluate the presence of organic structures and the penetration of irrigation solution. MATERIALS AND METHODS: Forty-two single-rooted, extracted human mandibular premolars were used in the study. Each tooth was decoronated at the cementoenamel junction and the root canals were instrumented using ProTaper rotary instruments in a crown-down manner. The specimens were randomly divided into five experimental groups (n = 7) Group (1) SonicMax, group (2) RinsEndo,group (3) EndoVac, group (4) PUI, group (5) MNI, and the control groups (n = 7). Each system used 2.5% sodium hypochlorite (NaOCl), 17% ethylenediamine tetraacetic acid (EDTA), and 2.5% NaOCl, respectively, in the experimental groups. The control group did not receive any final irrigation.The measurements were analyzed by employing two-way analysis of variance multivariate results to show significant differences between the length of the dentin tubules in the apical, middle, and coronal of the six groups. The post-hoc test was used when groups were compared by pairs. RESULTS: The results of this study indicate that among the five groups, the RinsEndo and EndoVac were found to be most effective in the cleaning of root canals. The RinsEndo shows highly significant results in the cleaning efficiency of the coronal and middle parts compared with the other groups. The cleaning efficiency in the apical area was the same for RinsEndo and EndoVac. CONCLUSION: The result of our study indicates that RinsEndo and EndoVac may be more effective in clinical practice.

Effectiveness of a novel chelating agent in removing calcium hydroxide using conventional and passive ultrasonic irrigation techniques.

Background: The present in vitro study aimed to compare the efficacy of a 25% copolymer of acrylic acid and maleic acid [poly(AA-co-MA)] and 17% of ethylenediaminetetraacetic acid (EDTA) in removing calcium hydroxide (CH) from root canals using the master apical file (MAF) and passive ultrasonic irrigation (PUI). Material and Methods: Fifty-eight teeth were dressed with CH. After 10 days, CH was removed using MAF+EDTA, MAF+poly(AA-co-MA), PUI+EDTA, and PUI+poly (AA-co-MA) (n=12). Ten teeth were used as controls. Residual CH was evaluated using a four-grade scoring system. Data analysis was performed using the Mann-Whitney U, Friedman, and Dunn-Bonferroni tests. Results: In the MAF and PUI groups, there was no significant difference in the CH scores between EDTA and Poly(AA-co-MA) (p<0.083). Although EDTA and poly(AA-co-MA) had lower CH scores when used with PUI, no significant difference was found between the two agents (p<0.083). Conclusions: Poly(AA-co-MA) did not remove significantly more CH than EDTA when used with MAF or PUI. Key words:Calcium hydroxide, Ethylenediaminetetraacetic acid, Acrylic acid, Maleic acid.

Graphene Oxide-based Endodontic Sealer: An in Vitro Study.

The failure of endodontic treatment is directly associated with microbial infection in the root canal or periapical areas. An endodontic sealer that is both bactericidal and biocompatible is essential for the success of root canal treatments. This is one of the vital issues yet to be solved in clinical dental practice. This in vitro study assessed the effectiveness of graphene oxide (GO) composites GO-CaF2 and GO-Ag-CaF2 as endodontic sealer materials. Dentin slices were coated with either the GO-based composites or commonly used root canal sealers (non-eugenol zinc oxide sealer). The coated slices were treated in 0.9% NaCl, phosphate-buffered saline (PBS), and simulated body fluid (SBF) at 37˚C for 24 hours to compare their sealing effect on the dentin surface. In addition, the radiopacity of these composites was examined to assess whether they complied with the requirements of a sealer for good radiographic visualization. Scanning electron microscopy showed the significant sealing capability of the composites as coating materials. Radiographic images confirmed their radiopacity. Mineral deposition indicated their bioactivity, especially of GO-Ag-CaF2, and thus it is potential for regenerative application. They were both previously shown to be bactericidal to oral microbes and cytocompatible with host cells. With such a unique assemblage of critical properties, these GO-based composites show promise as endodontic sealers for protection against reinfection in root canal treatment and enhanced success in endodontic treatment overall.

Evaluation of different irrigation techniques on dentin erosion and smear layer removal: A scanning electron microscopy study.

Aim: The purpose of the present study is to evaluate the effectiveness of different irrigation techniques EndoVac, RinsEndo, Canal CleanMax (CCMax), SonicMax, Passive Ultrasonic Irrigation (PUI), and Manual Needle Irrigation (MNI) on dentin erosion and smear layer removal using Scanning electron microscopy (SEM). Materials and Methods: Seventy extracted single-rooted teeth were instrumented with ProTaper rotary instruments. The roots were randomly divided into six experimental groups (n = 10): EndoVac, RinsEndo, CCMax, SonicMax, PUI, and MNI. Final irrigation was performed with NaOCl followed by ethylenediaminetetraacetic acid and NaOCl. Six roots served as control and were irrigated with only NaOCl. Next, the roots were sectioned in a buccolingual direction and the halves were examined by SEM. Smear layer and erosion scores were recorded in the cervical, middle and apical third of the roots. Data analysis was performed using the Kruskal-Wallis and Mann-Whitney U-tests with a level of significance α = 0.05. Results: PUI had the greatest amount of smear layer compared to other groups (P < 0.001). However, SonicMax had the greatest degree of erosion compared to RinsEndo, MNI, PUI, and EndoVac groups (P < 0.001) and CCMax group (P < 0.05). Conclusions: RinsEndo and EndoVac techniques left the least amount of smear layer while causing erosion the least compared to CCMax, PUI, and MNI techniques.

Interaction of backfilling techniques and MTA plugs with additives: Fracture strength and adaptation analyses.

The aims were to evaluate the effects of different additives on the adaptation of mineral trioxide aggregate (MTA) plugs before and after different backfilling techniques and analyze the interference of filling procedures on the fracture resistance of simulated immature teeth. The apical parts of 60 teeth were filled with MTA mixed with distilled water (DW), propylene glycol (PG) or calcium chloride (CaCl2) and backfilled with cold lateral condensation (CLC) or warm vertical compaction (WVC). The specimens were subjected to adaptation analysis and fracture testing. CaCl2 addition resulted in poor marginal adaptation, while PG addition significantly decreased the fracture values (p<0.05). WVC technique negatively affected the marginal adaptation of MTA-CaCl2 plugs and decreased the fracture values of teeth with MTA-PG plugs (p<0.05). Mixing MTA with DW can be recommended as apical plug when the remaining root canal space is going to be filled with either CLC or WVC techniques.

Final Irrigation Regimens Affect Fracture Resistance Values of Root-filled Teeth.

INTRODUCTION: The purpose of this study was to compare the effect of different final irrigation solutions on fracture resistance values (FRVs) of endodontically treated teeth. METHODS: Eighty extracted decoronated human incisors were used. Ten randomly selected roots were used as the negative control group. The remaining roots were prepared by the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) up to F2. Ten prepared roots were selected as the positive control. The other prepared roots were divided into 6 (n = 10) groups according to the final irrigation solution used: 5 mL saline, 17% EDTA, EDTA with a surfactant (REDTA), chlorhexidine, QMix (Dentsply Tulsa Dental Specialties, Tulsa, OK), and BioPure MTAD (Dentsply Tulsa Dental Specialties). In all groups, the final irrigation was performed for 1 minute except for the BioPure MTAD group; in this group, it was applied for 5 minutes according to the manufacturer's instructions. The specimens were filled with a single gutta-percha cone and AH 26 sealer (Dentsply, De Trey, Konstanz, Germany). After being stored under 37 °C and 100% humidity for a week, the specimens were loaded in a vertical direction at 1 mm/min speed until they were vertically fractured. The results were analyzed by the Kruskal-Wallis and Siegel Castellan tests. RESULTS: The negative control group showed the highest FRV. There were statistically significant differences between the negative and positive control groups (P < .05). Specimens irrigated with REDTA and QMix showed a higher FRV compared with the positive control group (P < .05). Specimens exposed to chlorhexidine and BioPure MTAD showed a lower FRV compared with the negative control group (P < .05). CONCLUSIONS: Root canal preparation weakens the tooth. The final irrigation regimen has an impact on the FRV. A short time exposure to irrigation solutions (REDTA and QMix) that include surfactants probably contributed to the higher FRV, instead of a long time exposure as done with BioPure MTAD.

Efficacy of Combined Use of Different Nickel-Titanium Files on Removing Root Canal Filling Materials.

INTRODUCTION: The aim of this study was to estimate the remaining amount of residual filling materials in root canals after retreatment using ProTaper Universal Retreatment (PTUR) files (Dentsply Maillefer, Ballaigues, Switzerland) alone or with the additional use of the Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel), Reciproc (VDW, Munich, Germany), or Hedström-files (H-file; VDW, Antaeos, Munich, Germany) with volumetric estimation using the stereologic method via cone-beam computed tomographic images. METHODS: Forty-eight mandibular premolars with single canals were used. The canals were instrumented with ProTaper rotary instruments up to F4 and filled with gutta-percha and AH26 sealer (Dentsply De Trey, Johnson City, TN). All the samples were placed into the silicone models. Samples were scanned with cone-beam computed tomographic imaging and assigned into 4 groups (n = 12) according to retreatment files: the PTUR system group, the PTUR system plus SAF group, the PTUR system plus Reciproc group, and the PTUR system plus H-file group. The specimens were rescanned after retreatment procedures, and the volume estimations of the remaining filling materials were performed using the stereologic method. Data were analyzed using Kruskal-Wallis and Dunn tests. RESULTS: There was no significant difference among the groups regarding mean percentage volumes of the filling materials before retreatment procedures (P > .05). None of the retreatment procedures provided complete removal of the filling materials. The additional use of the SAF did not significantly improve the removal of filling materials when compared with the PTUR system alone (P > .05). However, the additional use of Reciproc or hand H-files significantly improved the removal of filling materials when compared with the PTUR system alone (P < .05). CONCLUSIONS: The additional use of files with different motion kinetics improved the removal of root canal fillings; however, none of the systems completely removed the root canal filling material from the root canals.

Radiological, stereological, and microscopic evaluation of the quality of canal fillings in oval-shaped root canals prepared with self-adjusting file.

The aim of this study was to evaluate the quality of the canal fillings performed by thermoplastic technique (Herofill) and cold lateral condensation (CLC) techniques in oval shaped canals following self-adjusting file (SAF) preparation using radiological, stereological, and microscopic evaluation methods. Twelve pairs of oval-shaped root canals were prepared with SAF and filled using CLC (n = 12) or the Herofill system (n = 12). The quality of the root canal filling was evaluated by (i) scoring bidirectional storage phosphor plate images, (ii) stereological (volumetric) analysis of cone beam computerized tomography (CBCT) images, and (iii) microscopic analysis of the cross-sectioned area of the canal and gutta-percha via image analysis software. Chi-square test, t-test, and Mann-Whitney U-tests were used respectively (p < 0.05) for the aforementioned evaluations. 58.33% of the fillings (total n = 24) that were found to be sufficient in a bucco-lingual (BL) projection were considered insufficient in the mesio-distal (MD) projection according to radiological scoring. The difference in the findings between the two types of projections (BL and MD) was significant (p < 0.05). The results of the stereological evaluation of CBCT images and image analysis of cross-sections showed no statistically significant difference between the CLC and Herofill (p > 0.05). Herofill was not superior to cold lateral compaction. Stereology can be used to obtain unbiased information about the volume of root canal fillings. Both filling techniques failed to achieve the desirable goal of 0% empty volume in all of the cases and all evaluation systems confirmed this result. SCANNING 38:427-433, 2016. © 2015 Wiley Periodicals, Inc.

Effects of Different Rotary Files Combined with Different Irrigation Needles on Apically Extruded Debris.

The aim of this study was to compare the apically extruded debris associated with ProTaper Next and OneShape Apical files using two different irrigation needles, open-ended and closed-ended (Max-I-Probe). Forty-eight mandibular premolars were assigned to four groups (n=12) as follows: Group PTN-SN: Root canal was prepared with ProTaper Next (PTN) and irrigated with open-ended standard needle; Group PTN-MP: Root canal was prepared with PTN and irrigated with Max-I-Probe; Group OSA-SN: Root canal was prepared with OneShape Apical (OSA) and irrigated with open-ended needle; Group OSA-MP: Root canal was prepared with OSA and irrigated with Max-I-Probe. Debris extruded during instrumentation was collected into pre-weighed Eppendorf tubes. After storage in an incubator at 70 °C for 5 days, the Eppendorf tubes were weighed to obtain the final weight with extruded debris. The difference between pre-and post-debris weights was calculated and statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests (p<0.05). No statistically significant difference was observed between files and needles regarding amount of apically extruded debris (p>0.05). OneShape Apical and ProTaper Next resulted in extrusion of debris beyond the apical foramen, regardless of needle tip.

Evaluation of the effects of two novel irrigants on intraradicular dentine erosion, debris and smear layer removal.

OBJECTIVES: To evaluate the effects of copolymer of acrylic acid and maleic acid (Poly[AA-co-MA]) and calcium hypochlorite (Ca(OCl)2) on root canal dentin using scanning electron microscope (SEM). MATERIALS AND METHODS: Twenty-four single-rooted teeth were instrumented and the apical and coronal thirds of each root were removed, leaving the 5 mm middle thirds, which were then separated into two pieces longitudinally. The specimens were randomly divided into six groups and subjected to each irrigant for 5 min as follows: G1, Ca(OCl)2; G2, Poly(AA-co-MA); G3, Ca(OCl)2 + Poly(AA-co-MA); G4, sodium hypochlorite (NaOCl); G5, ethylenediaminetetraacetic acid (EDTA); G6, NaOCl+EDTA. The specimens were prepared for SEM evaluation. Smear layer, debris and erosion scores were recorded by two blinded examiners. One image from G3 was analyzed with energy dispersive spectroscopy (EDS) on suspicion of precipitate formation. Data were analyzed using the Kruskal-Wallis and Dunn tests. RESULTS: G1 and G4 showed the presence of debris and smear layer and they were statistically different from G2, G3, G5 and G6 where debris and smear layer were totally removed (p < 0.05). In G1 and G4, erosion evaluation could not be done because of debris and smear layer. G2, G3 and G5 showed no erosion, and there was no significant difference between them. G6 showed severe erosion and was statistically different from G2, G3 and G5 (p < 0.05). EDS microanalysis showed the presence of Na, P, and Ca elements on the surface. CONCLUSIONS: Poly(AA-co-MA) is effective in removing the smear layer and debris without causing erosion either alone or with Ca(OCl)2.

Effects of Different Rotary Files Combined with Different Irrigation Needles on Apically Extruded Debris

The aim of this study was to compare the apically extruded debris associated with ProTaper Next and OneShape Apical files using two different irrigation needles, open-ended and closed-ended (Max-I-Probe). Forty-eight mandibular premolars were assigned to four groups (n=12) as follows: Group PTN-SN: Root canal was prepared with ProTaper Next (PTN) and irrigated with open-ended standard needle; Group PTN-MP: Root canal was prepared with PTN and irrigated with Max-I-Probe; Group OSA-SN: Root canal was prepared with OneShape Apical (OSA) and irrigated with open-ended needle; Group OSA-MP: Root canal was prepared with OSA and irrigated with Max-I-Probe. Debris extruded during instrumentation was collected into pre-weighed Eppendorf tubes. After storage in an incubator at 70 °C for 5 days, the Eppendorf tubes were weighed to obtain the final weight with extruded debris. The difference between pre-and post-debris weights was calculated and statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests (p<0.05). No statistically significant difference was observed between files and needles regarding amount of apically extruded debris (p>0.05). OneShape Apical and ProTaper Next resulted in extrusion of debris beyond the apical foramen, regardless of needle tip.

O objetivo do presente estudo foi comparar a extrusão apical de restos de preparação de canais, associada às brocas ProTaper Next e OneShape Apical usando duas agulhas de irrigação, de ponta aberta e ponta fechada (Max-I-Probe). Quarenta e oito premolares inferiores foram divididos em quatro grupos (n=12): Grupo PTN-SN: o canal radicular foi preparado com ProTaper Next (PTN) e irrigado com agulha convencional de ponta aberta; Grupo PTN-MP: o canal radicular foi preparado com PTN e irrigado com Max-I-Probe; Grupo OSA-SN: o canal radicular foi preparado com OneShape Apical (OSA) e irrigado com agulha de ponta aberta; Grupo OSA-MP: o canal radicular foi preparado com OSA e irrigado com Max-I-Probe. Os restos extrudados apicalmente foram coletados em tubos Eppendorf previamente pesados. Após armazenagem por cinco dias a 70 °C, os tubos Eppendorf foram pesados para obter o peso final com os resíduos. A diferença entre as pesagens antes e depois foi calculada e análise estatística foi feita usando os testes de Kruskal-Wallis e Mann-Whitney U (p<0,05). Não houve diferença estatisticamente significante entre as brocas e agulhas com relação à quantidade de resíduos extrudados (p>0,05). As brocas ProTaper Next e OneShape Apical promoveram extrusão além do forame apical, independente do tipo de agulha utilizada.

A comparison of different irrigation systems and gravitational effect on final extrusion of the irrigant.

BACKGROUND: The aim of this study was to compare manual needle irrigation (MNI), RinsEndo (RE), and passive ultrasonic irrigation (PUI), and assess the effect of gravity on extrusion from the apex in vitro. MATERIAL AND METHODS: The distobuccal roots of molars were used and the canals were instrumented up to F2. Teeth were mounted on models, which permitted visualization and manipulation of the apices for necessary procedures. The models were placed in articulator to simulate the jaw. Six groups (G) were formed as: G1, G2 and G3 represented mandibular positioning of teeth and were irrigated with MNI, RE, and PUI, respectively, while G4, G5, and G6 represented maxillary positioning of teeth and were also irrigated in same sequence. Prior to the final irrigation, 72 cube-shaped foam pieces covered with aluminum foil were weighed and the values were recorded as the initial weights. The cubes were then placed on the apical part of each sample. Final irrigation was performed with distilled water and the cubes were weighed again to determine their final weight. Data were analyzed using Kruskal-Wallis and Mann-Whitney U post-hoc test (p<0.05). RESULTS: Irrespective of the irrigation technique used, the amount of irrigant extruded from the apex showed a statistically significant difference related to the effect of gravity (p<0.05). There was no statistically significant difference between irrigation methods (p>0.05). When the irrigation systems were compared to examine the effect of gravity, the significant difference was found between G2 and G5 (p<0.05). CONCLUSIONS: Within the limitations of this study, MNI and PUI were found to be reliable irrigation systems. Caution should be exercised when using RinsEndo. Key words:Final irrigation, manual needle irrigation, passive ultrasonic irrigation, RinsEndo.

Apical extrusion of debris and irrigant using novel preparation systems.

AIM: The aim of this in vitro study was to assess the amount of apically extruded debris and irrigant using Reciproc vs self-adjusting fle (SAF) and to investigate the effect, if any, of gravitational force via mandibular and maxillary positioning of the teeth. MATERIALS AND METHODS: Forty human mandibular premolars were randomly assigned to four groups of 10 teeth each. The root canals were instrumented according to the manufacturers' instructions using the Reciproc and SAF. Sodium hypochlorite was used as the irrigant. The apically extruded debris was collected in pre-weighted glass vials using the Myers and Montgomery method, and teeth were placed in vials both in downward and upward positions. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using two-way ANOVA with Bonferroni correction. RESULTS: All instrumentation techniques and positions caused measurable apical extrusion of debris. A significant difference was observed according to position and instrument used (p < 0.05). The Reciproc extruded significantly more debris than SAF and vial downward position extruded significantly more debris than upward position (p < 0.05). CONCLUSION: Under the conditions of this study, all systems caused apical debris extrusion, especially in the downward position. CLINICAL SIGNIFICANCE: According to results of this study, the SAF was associated with less debris extrusion compared to the Reciproc in both mandibular and maxillary positions.

Effectiveness of a new canal brushing technique in removing calcium hydroxide from the root canal system: A scanning electron microscope study.

AIM: To evaluate the effectiveness of Canal Brush technique removal Ca(OH)(2) from the root canal system using Scanning Electron Microscope (SEM). MATERIALS AND METHODS: Eighteen teeth were instrumented up to #40 and dressed with Ca(OH)(2). Ca(OH)(2) was removed with master apical file (MAF) (Group 1, n:6) and CanalBrush technique (Group 2, n:6). Six teeth served as positive and negative controls. The roots were splited in the buccolingual direction and prepared for SEM examination. Two examiners evaluated the wall cleanliness then statistical analysis was performed by Mann-Whitney U and Friedman tests. RESULTS: Differences in cleanliness were observed between Group 1 and Group 2 in the apical thirds (P=0.002). In the coronal and middle thirds, there were no differences between the two groups. CONCLUSIONS: It is essential to re-instrument the root canal walls using instrumentation techniques while irrigating with NaOCl and EDTA combination. The Canal Brush technique results in the packing effect of the Ca(OH)(2) through to the apex.

A comparison of three rotary systems and hand instrumentation technique for the elimination of Enterococcus faecalis from the root canal.

The aim of this study was to compare the in vitro reduction of a bacterial population in a root canal by mechanical instrumentation using three rotary systems and hand instrumentation technique. The root canals contaminated with a suspension of Enterococcus faecalis were instrumented using ProTaper, K3, HeroShaper and K-file hand instrumentation technique. Later the root canals were sampled. After serial dilutions, samples were incubated in culture media for 24 h. Bacterial colonies were counted and the results were given as number of colony-forming units per millilitre. The results showed that all the canal instrumentation systems reduced the number of bacterial cells in the root canals. Statistically, ProTaper instruments were more effective in reducing the number of bacteria than the other rotary files or hand instruments.

Evaluation of the radiopacity of different root canal sealers.

OBJECTIVE: The aims of this study were to compare the radiopacity of 8 root canal sealers relative to gutta-percha and dentin in standard discs and to evaluate the effect of these sealers on the radiopacity of root canal fillings in simulated canals. STUDY DESIGN: Radiographs were taken of 1-mm-thick specimens of 8 root canal sealers (Diaket, Endion, MTA, Endofil, Roeko Seal, Sealite, AH26, AH Plus) and gutta-percha, a 1-mm-thick human tooth slice, and aluminum stepwedge.Simulated canals were used to evaluate the effect of the sealer on radiopacity of the root fillings. After enlargement of the simulated canals with ProTaper instrument, root canals were filled with these 8 sealers alone and with single ProTaper gutta-percha cone. Radiographs of all filled simulated canals were taken with an aluminum stepwedge. RESULTS: All the sealers demonstrated greater radiopacity than dentin (0.7940 mm Al) (P < .001). AH Plus showed the highest radiopacity in the standard disc group (Group 1) (8.9881 mm Al) (P < .001), and in the sealer group in simulated canals (Group 2) (9.2100 mm Al) (P < .001). In the sealer plus gutta-percha group in simulated canals (Group 3), Sealite plus gutta-percha showed greater radiopacity (8.4460 mm Al) (P < .001). CONCLUSION: Whether the opacity of the sealers alone is more or less than 3 mm Al, their radiopacity is increased when they are used in combination with gutta-percha, because of its higher radiopacity. However, when sealers are used in conjunction with gutta-percha, they can affect the radiopacity of the root canal filling according to their type and thickness.

Spontaneously healed root fractures: two case reports.

We report on two undiagnosed horizontal root fractures of two maxillary right central incisors in two different patients caused by dental trauma which occurred several years ago. These fractures were discovered during a routine full-mouth radiographic examination. While, in case one, the fracture was located in the middle-third of the root, it was in the cervical-third of the root in case two. The fractured teeth were observed to have healed spontaneously without any sign or symptom, and tested as vital to electric pulp test.

Cytotoxic effects of four different endodontic materials in human periodontal ligament fibroblasts.

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.