Handan Ersev

Cytotoxic and mutagenic potencies of various root canal filling materials in eukaryotic and prokaryotic cells in vitro

Cytotoxic and mutagenic effects of root canal filling cements of various chemical composition were determined in vitro. Materials set for 24 h and 1 wk were eluted for 24 h in cell culture medium (cytotoxicity testing) and dimethyl sulfoxide or physiological saline (mutagenicity testing). The differences between cytotoxic potencies of eluates of the endodontic materials on L-929 cells were quantified colorimetrically (MTT test). Eluates of Traitement SPAD were about 5- to 30-fold more toxic than silver-free AH26, Tubli-Seal, CRCS, and Endomethsone N. The rank order of the toxic effects depended on the setting time of mixed materials. Dimethyl sulfoxide and saline eluates of Traitement SPAD, Tubli-Seal, Endomethasone N, CRCS, and Ketac-Endo were not mutagenic in the Ames test. Both eluates of silver-free AH26 set for 24 h were weakly mutagenic in Salmonella typhimurium TA100. Weak mutagenicity of saline eluates of the material was also observed in TA97a and TA102. These results point to the possibility that mixed silver-free AH26 might contain small amounts of two mutagenic substances: bisphenol A diglycidyl ether and formaldehyde.

Tetracycline HCl Solution as a Root Canal Irrigant

The effect of tetracycline hydrochloride as an endodontic irrigant on smear layer removal was examined by scanning electron microscopy and compared with bidistilled water, 2.5% sodium hypochlorite (NaOCl), and 50% citric acid in 20 extracted teeth. Five teeth, as a control, were irrigated with bidistilled water only in group 1. All the other groups were irrigated with NaOCI during instrumentation. The final rinses were NaOCl in group 2, citric acid in group 3, and 1% tetracycline hydrochloride in group 4. Scanning electron microscopic results and statistical analysis revealed that bidistilled water and NaOCl were ineffective in removing the smear layer, whereas citric acid and tetracycline hydrochloride were significantly more effective (p < 0.001). No statistically significant difference was detected between tetracycline hydrochloride and citric acid (p > 0.05). However tetracycline hydrochloride demineralized less peritubular dentin.

Cytotoxicity of 5 endodontic sealers on L929 cell line and human dental pulp cells.

AIM To investigate the cytotoxicity of five root canal sealers on L929 mouse fibroblasts and primary human dental pulp cells. METHODOLOGY Cylindrical specimens of AH Plus (Dentsply De Trey GmbH, Konstanz, Germany), RoekoSeal (Coltène Whaledent, Langenau, Germany), EndoREZ (Ultradent Products Inc., South Jordan, UT, USA), Epiphany (Pentron Clinical Technologies, LLCC, Wallingford, CT, USA) and Activ GP (Brasseller Inc., USA, Savannah, GA, USA) were kept at 37 °C in a humidified atmosphere of 5% CO(2) for thrice the length of the setting time given by the manufacturer. Extraction of specimens was performed after setting in cell growth medium for 1, 4 and 7 days. Undiluted, 50% and 25% diluted eluates were incubated with cultured cells for 24 and 72 h. Cytotoxicity was assessed using MTS colorimetric bioassay. Kruskal-Wallis test and post hoc Dunns multiple comparison test were used to compare the sealers and diluted/undiluted eluates in terms of cell viability (% of control). Friedman test and post hoc Dunns multiple comparison test were performed to compare extraction periods. Wilcoxon test was utilized in comparing 24- and 72-h readings. RESULTS Undiluted 1-day eluate of Activ GP was significantly more cytotoxic than all other sealers (P < 0.0001). Undiluted 4- and 7-day eluates of Epiphany and Activ GP were significantly more cytotoxic than the other three sealers (P < 0.0001). Diluted eluates of Activ GP and Epiphany were generally less toxic than the undiluted ones. The cytotoxicity of Epiphany significantly increased as the extraction period increased (P < 0.0001). Epiphany became more toxic with time of exposure to cells. No or minimal cytotoxicity was observed with RoekoSeal, AH Plus and EndoREZ. CONCLUSIONS The sealers exhibited varying degrees of cytotoxicity dependent on their chemical composition.

The efficacy of ProTaper Universal rotary retreatment instrumentation to remove single gutta‐percha cones cemented with several endodontic sealers

AIM To evaluate residual root filling material following removal of three newly developed root canal sealers used with a matched-taper single-cone root filling technique and to compare the efficacy of ProTaper Universal rotary retreatment instruments with that of a conventional manual technique. METHODOLOGY The canals of 120 palatal roots in maxillary molar teeth were instrumented with EndoWave nickel-titanium rotary instruments and filled using Hybrid Root SEAL, EndoSequence BC Sealer, Activ GP system or AH Plus with matched-taper single gutta-percha cones. The root fillings were then removed with ProTaper Universal retreatment rotary instruments or a manual technique. Buccolingual and proximal digital radiographs of the roots were exposed to determine the area of remaining filling material in the coronal, middle and apical thirds. The area percentages of remaining filling material in each third and total canal area were calculated. Data were analysed statistically with Kruskal-Wallis and Mann-Whitney U-tests. The level of significance was set at P<0.05. RESULTS Irrespective of the sealer type and retreatment technique, filling material could not be removed completely from the root canals. Significantly, more remaining filling material was observed in the apical third (P<0.05). When comparing the sealers, the only significant difference was detected between AH Plus/manual and Activ GP/manual groups with respect to residual material in the total canal area (P<0.05). There were no significant differences between manual and ProTaper groups. CONCLUSIONS When using gross radiographic criteria, the Activ GP was more effectively removed from root canals than AH Plus with hand instrumentation. Hybrid Root SEAL, EndoSequence BC Sealer and AH Plus were removed to a similar extent. ProTaper Universal retreatment instruments were as safe and effective as hand instruments in reaching the working length.

A comparison of the shaping effects of 5 nickel-titanium rotary instruments in simulated S-shaped canals

OBJECTIVE The objective of this study was to compare the shaping efficacy of 5 Ni-Ti rotary instruments with different cross-sectional designs in simulated S-shaped resin root canals. STUDY DESIGN One hundred canals (n = 20) were instrumented to apical size 0.04/25 with ProFile, K3, NiTi-TEE, EndoWave, or HeroShaper. Pre- and postoperative images were superimposed. Width of resin removal was measured. Total amount of material removal, amount and direction of transportation, and centering ratios were determined. Data were analyzed using 1-way ANOVA and post hoc Tukey and Newman-Keuls multiple comparison tests. RESULTS In terms of centering ratio and amount of transportation, ProFile followed by K3 gave the best results almost throughout the whole canal. However, ProFile created insufficient taper. Canals instrumented with the other 3 systems were transported and lacked flow. CONCLUSION The K3 system, probably owing to its cross-sectional design and sequence encompassing a high number of instruments, seems under the conditions of this study to be a better choice in preparing S-shaped simulated root canals.

Comparison of the fracture resistance of simulated immature permanent teeth using various canal filling materials and fiber posts

BACKGROUND   The purpose of this study was to compare the fracture resistances of immature teeth treated with MTA along with root canal obturation methods using AH Plus, MetaSEAL, MTA Fillapex sealers + lateral compaction technique, and Unicore quartz fiber posts. MATERIALS AND METHODS   Fifty single-rooted maxillary anterior teeth were divided into five groups. The crowns were dissected and root canals were enlarged. #6 Peeso reamers were allowed to protrude 1 mm. beyond the apex to simulate immature teeth. The apical 4-5 mm of each tooth was filled using Angelus white MTA. The remaining portions of canals were obturated as follows: Group 1: No backfilling (control), Group 2: AH Plus + gutta-percha, lateral compaction, Group 3: MetaSEAL + gutta-percha, lateral compaction, Group 4: MTA Fillapex + gutta-percha, lateral compaction, Group 5: UniCore Fiber posts luted using PermaFlo DC. The specimens were embedded into self-curing acrylic poured into identical cylinders which were mounted on a jig providing a 45° angle. A compressive load increasing at 1 mm min(-1) was applied and the maximum load at which fracture occurred was recorded. Statistical analysis was performed using Kruskal-Wallis and Dunns multiple tests. RESULTS   The highest fracture resistance was obtained with Group 5 (Fiber posts) whereas Group 4 (MTA Fillapex) yielded the lowest values. The mean fracture resistance value of Group 2 (AH Plus) was significantly higher than Group 4 (MTA Fillapex) (P = 0.001). The mean fracture value of Group 5 (Fiber posts) was significantly higher than Group 2 (AH Plus), Group 3 (MetaSEAL), and Group 4 (MTA Fillapex) (P = 0.02, 0.004, and 0.0001, respectively). CONCLUSION   Within the limitations of this study, UniCore quartz fiber posts provided the highest resistance. This methodology may specifically be advantageous for teeth with arrest of development at early stages, as these teeth are more susceptible to fracture owing to their excessively weak dentinal walls.

Effect of Rotational Speed on Root Canal Preparation with Hero 642 Rotary Ni-Ti Instruments

The purpose of this study was to evaluate the influence of Hero 642 rotary Ni-Ti instruments driven at 300, 400, or 600 rpm on root canal straightening, loss of working length, and instrument breakage. Sixty mesial root canals from extracted human mandibular molars were divided into 3 groups of 20 each and were instrumented at the aforementioned rotational speeds with a crown-down technique. Using a digital intraoral radiography system directly on the images of pre- and postoperative radiographs, degrees of canal curvatures were measured and recorded. Statistical analysis showed that final canal curvatures and working lengths were significantly reduced compared with those of original values in each group (p < 0.001). However, using Hero 642 rotary Ni-Ti system at different rotational speeds had no effect on canal curvature and working length alterations (p > 0.05). No file breakage was observed in any of the groups.

Resistance to Vertical Root Fracture of Endodontically Treated Teeth with MetaSEAL

INTRODUCTION The purpose of this in vitro study was to assess the influence of MetaSEAL and AH Plus on the resistance to vertical root fracture of endodontically treated teeth when either the matched-taper single-cone or lateral condensation technique was used. METHODS Ninety extracted single-canal mandibular premolar teeth were sectioned, leaving a standard root length of 13 mm. The buccolingual and mesiodistal diameters were measured, and the teeth were randomly divided into 6 groups (n = 15). There were no statistically significant differences between the groups in terms of the diameters. In group 1, no instrumentation or obturation was performed. The rest of the roots were chemomechanically prepared with nickel-titanium ProTaper rotary instruments up to size F3 at the working length. Group 2 was left unobturated. Groups 3 and 4 were obturated with AH Plus used with the matched-taper single-cone and lateral condensation techniques, respectively. In groups 5 and 6, MetaSEAL was used instead of AH Plus. All of the roots were mounted vertically in self-curing acrylic resin blocks that exposed 8 mm of the coronal part. Then the roots were subjected to a vertical loading force (1 mm/min). The force required to produce a fracture was recorded in newtons. The data were analyzed by using Kruskal-Wallis and post hoc Dunn multiple comparison tests (P < .05). RESULTS Although we did not detect statistical significance, there was a substantial difference between the fracture resistance values of the intact and instrumented but not obturated roots. The groups in which AH Plus and MetaSEAL were used with the matched-taper single-cone technique showed significantly higher fracture resistance values than the instrumented but not obturated roots (P < .05). There were no significant differences between the groups submitted to the matched-taper single-cone technique. The force required to fracture the roots in the group treated with AH Plus and the lateral condensation technique was similar to that required to fracture intact roots, whereas the group treated with MetaSEAL and the lateral condensation technique revealed comparable values to the instrumented but not obturated roots. CONCLUSIONS When used with the matched-taper single-cone technique, MetaSEAL and AH Plus have the potential to reinforce endodontically treated teeth.

Five-year follow-up of a root canal filling material in the maxillary sinus: a case report

This report describes the 5-year clinical and radiographic follow-up of an accidental extrusion of a root canal filling material into the maxillary sinus and emphasizes the importance of monitoring of similar cases. The most favorable prognosis is achieved by surgically removing the extruded material from the sinus. Excess zinc oxide-eugenol-based materials in the sinus might cause aspergillosis sinusitis, and this entity often needs many years to develop. In this case, endomethasone was the filling material; however, the patient refused to undergo any surgical intervention. After a follow-up period of 5 years, the patient had no symptoms and radiographic examination disclosed no pathologic changes in the antrum.

Endodontic and surgical management of a maxillary lateral incisor with type III dens invaginatus: a 12-month follow-up

This article reports the endodontic and surgical management and 12-month follow-up of a maxillary lateral incisor diagnosed as type III dens invaginatus. A 21-year-old male patient presented to our clinics with complaints of pain and swelling in the right maxillary region. Intraoral and radiographical examination disclosed the presence of a peg-shaped maxillary right lateral incisor diagnosed as type III dens invaginatus. Root canal treatment combined with periapical surgery was initiated. After the completion of root canal treatment for both maxillary right central and lateral incisors, periapical surgery was scheduled. During the surgery, periapical granulation tissue was curreted and bovine-derived hydroxil apatite (Unilab-Surgibone, Mississauga, Ontario, Canada) covered with collagen membrane (Unilab-Surgibone) was placed in the resorptive areas. ProRoot MTA (Dentsply, Tulsa, OK) was placed as a root end filling material. Postoperative 12-month follow-up revaled a satisfactory healing process.