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PubMed1998

Microleakage of super-EBA with and without finishing as determined by the fluid filtration method.

Super-EBA (SEBA) has been used as a root-end filling material because of its superior sealing properties and clinical success. The purpose of this study was to evaluate whether finishing SEBA after it had set would affect the apical seal. Sixty-five extracted maxillary anterior teeth were instrumented and obturated with a single gutta-percha master cone. The root end was resected, and a 3 mm deep root-end preparation was made using ultrasonic tips. Teeth were randomly divided into three groups. Group 1 received SEBA and was finished with a 30-flute high-speed finishing bur. Group 2 received SEBA, which was cold-burnished with a ball burnisher. Temporary Endodontic Restorative Material was used as the negative control in group 3. Microleakage (microliter/min) was measured under 10 psi using the fluid filtration method at days 1, 7, 30, 90, and 180. SEBA/finished exhibited significant microleakage at day 1 when compared with the burnished group. The differences in leakage were not significant at any other time period.

Dental Leakage↗
PubMed2001

Sealing ability of Dyract, Geristore, IRM, and super-EBA as root-end filling materials.

The purpose of this study was to evaluate the apical sealing ability of two compomers (Dyract and Geristore), IRM, and Super-EBA. Forty single canal roots from human teeth were instrumented until a size 40 file extended 1 mm beyond the apex. One millimeter of root apex was removed and a preparation 3-mm deep was prepared. Roots were divided into 4 groups of 10 roots each and filled with IRM, Super-EBA, Dyract, or Geristore. Canals were not obturated to ensure that any leakage was due to the apical filling material alone. Each root was then affixed to a fluid filtration device and subjected to a pressure of 14 cm of H2O, which has been determined to be the normal pulpal tissue pressure. The integrity of the seal was evaluated for 5 min at 1, 7, 30, and 180 days. Data were analyzed at each time point using one-way analysis of variance on ranks. The results of this study suggest that the new compomers Dyract and Geristore are equal or superior to IRM and equivalent to Super-EBA in their ability to reduce apical leakage when used as retrofilling materials.

Analysis of Variance↗
PubMed1995

Investigation of mineral trioxide aggregate for root-end filling in dogs.

Numerous compounds have been used as root-end filling materials. Based on the results of in vitro and intraosseous implantation tests, mineral trioxide aggregate (MTA) seems to have potential as a root-end filling material. The purpose of this study was to examine the periradicular tissue response of dogs to MTA and amalgam. Lesions were developed in periradicular tissues of 46 roots in six beagle dogs. The canals on half of the roots were instrumented and obturated with gutta-percha and sealer, and their access cavities were sealed with MTA. The remaining root canals were instrumented and obturated with gutta-percha and sealer, and their access cavities were sealed with MTA. The remaining root canals were instrumented and obturated with gutta-percha without root canal sealer. The access cavities of the teeth in this group were left open to the oral cavity. After surgical resection of roots, half of the root-end cavities were filled with amalgam and the rest with MTA. The periradicular tissue response of the dogs was evaluated histologically 2 to 5 and 10 to 18 wk following periradicular surgery. Statistical analysis of the results showed less periradicular inflammation and more fibrous capsules adjacent to MTA, compared with amalgam. In addition, the presence of cementum on the surface of MTA was a frequent finding. The results show that MTA can be used as a root-end filling material.

Aluminum Compounds↗
PubMed1998

Longitudinal study of the microleakage of two root-end filling materials using a fluid conductive system.

A comparison of the microleakage of mineral trioxide aggregate (MTA) and a high copper admix amalgam (Valiant PhD) in root-end preparations was made using a fluid conductive device. Thirty-three bilaterally matched pairs of extracted, single-rooted teeth were prepared and obturated using lateral compaction of gutta-percha. The root-ends were resected and 3-mm-deep class I cavity preparations were made. The root-end preparations were filled with either amalgam or MTA. Guttapercha coronal to the root-end fillings was removed leaving only the amalgam or MTA present as a barrier to fluid movement. In the fluid-conductive device, the root canals were filled with a phosphate-buffered saline solution at a pressure of 10 psi. The flow of fluid was measured and compared at 1, 2, 3, 4, 8, 12, 16, 20, and 24 wk. The results showed amalgam to have significantly higher microleakage after 4 wk and higher variability compared with the MTA group.

Aluminum Compounds↗
PubMed1995

Leakage of amalgam and Super-EBA root-end fillings using two preparation techniques and surgical microscopy.

An in vitro dye leakage study was conducted to test the root-end sealing ability of amalgam with varnish or Super-EBA using two root-end preparation techniques and surgical microscopy. Sixty-four single-rooted teeth were instrumented and obturated with gutta-percha. Teeth were randomly placed into four groups. Two groups received perpendicular root-end resections, 3-mm-deep ultrasonic root-end preparations, and either amalgam with varnish or Super-EBA root-end fillings. The other two groups received beveled root-end resections, 3-mm-deep micro-handpiece preparations, and either amalgam with varnish or Super-EBA. All root-end procedures were performed at x5 to x8 magnification. Micro-leakage was assessed at 4 months using methylene blue dye and a passive hydrostatic pressure technique. Statistical analysis showed that, regardless of technique, Super-EBA leaked significantly less than amalgam with varnish. There was no significant difference between the two root-end resection and preparation techniques.

Chi-Square Distribution↗
PubMed1992

Scanning electron microscopic study of the apical dentine surfaces lased with ND:YAG laser following apicectomy and retrofill.

The purpose of this investigation was to study the effects of a Nd:YAG laser on the cut surface of teeth using scanning electron microscopy (SEM). Eighteen single-rooted teeth were cleaned, shaped, and obturated with gutta-percha and root canal sealer. The apical 3 mm of each tooth were resected with a diamond fissure bur, and the teeth were randomly divided into two groups of nine teeth each. The resected surface of each root in one group was lased twice. The duration of lasing and the number of pulses were recorded for each tooth. The teeth were air dried, mounted on stubs, sputter-coated with gold-palladium and examined under SEM. Application of the Nd:YAG laser caused melting of apical dentine surfaces. The melted material resembled the appearance of glazed interconnected droplets. Resolidification and recrystalization of the melted areas appeared to be incomplete and discontinuous. Some areas between the glazed regions appeared similar to those of non-lased apical dentine resected root surfaces.

Apicoectomy↗
PubMed1997

An in vitro investigation of coronal leakage with three gutta-percha backfilling techniques.

The aim of this study was to compare the backfilling capabilities of System B, Obtura II and Alphaseal. Forty-six lower premolar teeth were prepared chemomechanically and allocated to four experimental and two control groups. Ten were obturated using lateral condensation as a standard and 30 were obturated in the apical third using the System B. The latter 30 teeth were then backfilled using one of three techniques, System B, Obtura II or Alphaseal (n = 10 in each group). The remaining six teeth served as controls. Roots were radiographed from the proximal in order to evaluate voids and then placed in India ink for 65 h prior to being demineralized and rendered transparent, coronal leakage was quantified by linear measurement of ink penetration. No significant difference was found between the four groups with respect to the presence of voids radiographically (P < 0.05). The difference in leakage between the System B and Obtura II groups was not significant (P > 0.05). Both System B and Obtura II leaked significantly less than Alphaseal and lateral condensation (P < 0.001).

Bicuspid↗
PubMed1991

A 24-week study of the microleakage of four retrofilling materials using a fluid filtration method.

The microleakage after retrofillings of amalgam, amalgam with cavity varnish, silver-containing glass ionomer cement, and intermediate restorative material was compared in vitro. Thirty-six extracted human incisors and canines were instrumented, obturated with gutta-percha without sealer, subjected to apicoectomy, and retrofilled with the materials described above. After removal of the gutta-percha filling, the microleakage from both directions (apically and coronally) was measured quantitatively and longitudinally for 24 wk after filling by a fluid filtration technique. All four retrofilling materials revealed some apical and coronal leakage at all time periods. The amalgam group showed statistically significant (p less than 0.001) apical leakage at 1.5 h. The use of cavity varnish significantly reduced the apical leakage of the amalgam group at 1.5 h. The silver-containing glass ionomer cement and intermediate restorative material groups showed significantly (p less than 0.05) less coronal leakage compared with the amalgam group at 1.5 h. Scanning electron microscopy of selected samples showed marginal defects of approximately 5 microns between the root dentin and the retrofilling material.

Cermet Cements↗
PubMed1998

Sealing ability of super EBA and Dyract as root-end fillings: a study in vitro.

The purpose of this study was to compare, in vitro, the sealing ability of Super EBA and a compomer, Dyract, as root-end filling materials. Forty-eight single-rooted human teeth were cleaned, shaped and obturated with gutta-percha. The root apices were resected and root-end cavities were prepared. Twenty teeth were retrofilled with Super EBA and Dyract; eight teeth served as positive and negative controls. Half of the teeth in each group were immersed in basic fuschin for 4 weeks, the other half for 12 weeks. The teeth were then embedded in resin, sectioned, and the maximum extent of dye penetration measured. Statistical analysis (ANOVA) did not reveal a significant difference between the two materials at 4 weeks. At 12 weeks, the extent of dye penetration was statistically significant with Super EBA leaking more than Dyract (P = 0.002). Moreover, the extent of the dye penetration was statistically significantly different for Super EBA between the 4- and 12-week groups (P = 0), whereas no such difference was found for Dyract. Thus, the sealing ability of Dyract was found to be better than Super EBA at 12 weeks.

Compomers↗
PubMed1992

Effects of Nd:YAG laser on apical seal of teeth after apicoectomy and retrofill.

The application of Nd:YAG laser to tooth surface can change its surface permeability. The purpose of this study was to investigate the effects of Nd:YAG laser on the permeability of dentin following apicoectomy and retrofill. Sixty single-rooted teeth were randomly assigned to six groups of 10 teeth each. The six groups were arranged in three pairs, experimental and control groups. The canals of teeth in pairs 1 and 2 were cleaned, shaped, obturated, and their apical 2 mm were resected. A class I preparation was prepared and filled with amalgam in each tooth in pair 1. The apical 2 mm of each tooth in pair 3 was removed, and a class I preparation was prepared and filled with amalgam. The apical surface of resected roots in half of the samples in each pair was lased twice by using Nd:YAG laser. The duration of lasing and the number of pulses were recorded for each tooth. After application of nail polish to the unoperated surface of each tooth, the teeth were placed in 0.5% methylene blue dye for 48 h. The amount of dye penetration in sagittal sections of each tooth was measured. The amount of dye penetration was significantly lower in lased roots than in nonlased ones (p < 0.05). Based on our results, it appears that application of Nd:YAG laser reduces the permeability of resected roots.

Analysis of Variance↗
PubMed1999

A comparison in vitro of fibroblast attachment to resected root-ends.

AIM: The aim of this study was to investigate the effect of surface morphology of root ends resected with various bur configurations on fibroblast attachment. METHODOLOGY: Seventy-two human single-rooted teeth were collected and decoronated. The root canals were instrumented, and then obturated with thermoplasticized gutta-percha using AH-26 as the sealer. The roots were randomly divided into eight different groups, and apical root-end resections were performed using eight different instruments, which included high and low speed burs and a scalpel blade. After each root was resected, the surface area of the root end was measured. Cultured human periodontal ligament fibroblasts were radiolabelled and then allowed to attach, in vitro, to the root-ends. Cell attachment to the resected root-ends was determined by counting in a liquid scintillation system and expressed as the number of decays per min/mm2 (DPM/mm2) of root surface. RESULTS: There was no significant difference in fibroblast attachment to the root-ends prepared with various instruments. CONCLUSIONS: These findings indicate that the choice of instrument for root-end resection has little influence on the initial attachment of fibroblasts, and thus may have little effect on healing following root-end resection.

Analysis of Variance↗
PubMed1999

Ultrasonic root-end preparation with smooth and diamond-coated tips.

The purpose of this study was to compare the effects of smooth and diamond-coated ultrasonic retrotips on the external and internal surfaces of root-end preparations with the aid of a scanning electron microscope (SEM). Forty-four mesial roots of human mandibular molars were selected. The canals were cleaned, shaped and obturated using gutta-percha and sealer. The apical portions were resected at a 45 degrees-angle bevel exposing both mesial canals and the isthmus area. The roots were then divided into two groups according to the type of root-end preparation: Group A--performed with smooth retrotips (S) and Group B--performed with diamond-coated retrotips (DC). The specimens were coded and prepared for SEM evaluation. Observations of the external surface preparation showed that the S and DC retrotips produced very well-centered cavities involving both canals and isthmus area with minimal deviations and no perforative defects. When the internal surface of the root-end preparations was evaluated, it was evident that the use of S retrotips resulted in clean canal walls with little superficial debris and smear layer. Internal canal surfaces done with DC retrotips were irregular showing patent grooves, in contrast with the more uniform, regular and smoother surfaces when S retrotips were employed.

Apicoectomy↗
PubMed1994

Ultrasonic root-end preparation, Part 2. Microleakage of EBA root-end fillings.

The effect of three methods of root-end preparation, following apical resection, on the apical seal of root-end fillings, was studied in vitro. Root canals of 116 single-rooted teeth with mature apices were prepared chemomechanically and obturated with gutta-percha and sealer. The root ends were resected with a diamond bur under water coolant and were prepared as follows: group I a size 010 round bur was used to prepare an apical cavity 2-3 mm down the long axis of the root; group II treatment as per group 1 followed by a 60-s rinse with a solution of 10:3 (10% citric acid: 3% Fe2Cl3); and group III an ultrasonic retrotip was used to prepare a 2-3 mm deep apical cavity. The root end was restored with an EBA cement. Apical leakage was determined using India ink after 7 days and 7 months. The teeth were demineralized, rendered transparent and linear dye penetration was recorded. Results showed that there was no significant difference in leakage between the groups at each time interval (P > 0.05) but there was increased leakage after 7 months (P < 0.01). Cracking of the root surface was seen most often with the ultrasonically prepared roots (P < 0.001).

Chi-Square Distribution↗
PubMed1995

Comparative investigation of marginal adaptation of mineral trioxide aggregate and other commonly used root-end filling materials.

This study investigated the marginal adaptation of mineral trioxide aggregate (MTA) as a root-end filling material, compared with commonly used root-end filling materials by scanning electron microscopy (SEM). Eighty-eight single-rooted freshly extracted human teeth were cleaned, shaped, and obturated with gutta-percha and root canal sealer. Following root-end resection and cavity preparation, the root-end cavities were filled with amalgam, Super-EBA, Intermediate Restorative Material (IRM), or MTA. Using a slow-speed diamond saw, 40 roots were longitudinally sectioned into two halves. Resin replicas of resected root ends of the remaining nonsectioned roots were also prepared. After mounting longitudinal sections of roots and resin replicas of resected roots on aluminum stubs, the distance between the test root-end filling materials and surrounding dentin was measured at four points under SEM. Examination of the original samples showed numerous artifacts in the longitudinal sections of the specimens. In contrast, the resin replicas of resected and filled root ends had no artifacts. Statistical analysis of data comparing gap sizes between the root-end filling materials and their surrounding dentin shows that MTA had better adaptation compared with amalgam, Super-EBA, and IRM.

Aluminum Compounds↗
PubMed1993

A comparative sealability study of different retrofilling materials.

The purpose of this study was to compare the sealing ability of high-copper amalgam, glass ionomer cement, and silver glass ionomer cement as retrofilling materials when used with and without varnish. Seventy extracted human single-rooted anterior teeth were instrumented and the root canals obturated with laterally condensed gutta-percha and sealer. The apical 3 mm of each root was resected and a 2 mm-deep apical Class I preparation cut. The roots were then randomly allocated to six groups of 10 teeth and retrofilled with one of the experiment materials. Group I comprised high-copper amalgam; group 2, high-copper amalgam with cavity varnish; group 3, glass ionomer cement without varnish; group 4, glass ionomer cement with varnish; group 5, silver glass ionomer cement without varnish; and group 6, silver glass ionomer cement with varnish. Two groups of five roots each were used as positive and negative controls. The root surfaces were coated with nail polish and specimens immersed in 2% methylene blue solution for 14 days. After vertical sectioning, dye penetration was examined under a stereomicroscope. The results of the study were analysed statistically. The sealing ability of the conventional glass ionomer cement with varnish was significantly better while dye penetration was higher in silver glass ionomer cement without varnish group than the other groups (P < 0.01).

Acid Etching, Dental↗
PubMed1999

A scanning electron microscopic evaluation of root surfaces and the gutta-percha interface following root-end resection in vitro.

AIM: The aim of this study was to evaluate the effects that various commonly used instruments have on root surface morphology, the obturating material, and the interface between the obturation and the root canal walls following root-end resection in vitro. METHODOLOGY: Sixty human single-rooted teeth with fully formed apices were collected and decoronated. The root canals were instrumented, and then obturated with thermoplasticized gutta-percha using AH-26 as the sealer. The roots were randomly divided into 12 different groups, and apical root-end resections were performed using eight different instrument configurations, and two different directions in which the bur moved across the root face in relation to its direction of rotation. Epoxy resin replicas of the resected root ends were examined using scanning electron microscopy. RESULTS: Each instrument produced a characteristic surface finish on the resected root end that mirrored its cutting profile. Irrespective of the design of the bur used, smearing and shredding of the gutta-percha across the root face occurred only when the handpiece was moved across the root face in reverse direction in relation to the direction of rotation of the bur. CONCLUSIONS: To ensure minimal disruption and distortion of the root filling and to prevent shredding of the gutta-percha interface, care should be taken to ensure that the final pass of the bur across the root canal is in the correct direction in relation to its direction of rotation.

Bismuth↗
PubMed1995

Marginal leakage of Gallium Alloy root-end fillings: an in-vitro assessment.

The sealing ability of amalgam and Gallium Alloy Gallium Filling (GF) root-end fillings was evaluated in vitro using a highly uniform collection of sheep incisor roots. Following ultrasonic canal debridement and orthograde obturation with gutta-percha and sealer, root-end cavities were prepared in 100 roots and filled with amalgam (50 teeth) or Gallium Alloy GF (50 teeth), Twenty-five teeth from each group were subjected to immediate dye leakage assessment under vacuum conditions with methylene blue dye (2%), pH 7. Linear dye penetration was measured following longitudinal splitting. The other 25 teeth from each group were incubated in Ringer's solution for 12 weeks before leakage assessment by the same method. Control teeth were included in each component of the study. Mean linear dye penetration was: amalgam--5.17 mm at baseline, 2.33 mm after 12 week's incubation; Gallium Alloy GF--2.21 mm at baseline, 1.41 mm after 12 week's incubation. The apical marginal seal of both materials improved significantly following storage in Ringer's solution (P<0.001). Gallium Alloy GF provided a better apical seal than amalgam, both at baseline and following storage (P<0.001). Subjective evaluation of the general handling characteristics of Gallium Alloy GF revealed that it was a more difficult material to manipulate than amalgam, largely because of its wetting ability and consequent adhesion to dental instruments.

Alloys↗
PubMed2002

Case selection for apical surgery: a retrospective evaluation of associated factors and rational.

Endodontic failures associated with poor quality of endodontics respond favorably to retreatment. Nevertheless, under certain clinical conditions, apicoectomy should be the preferred procedure. A retrospective survey of 200 roots that were referred for apical surgery revealed that 83% of the roots were inadequately obturated, including 8.5% with no root canal filling at all. In 49 of the roots in this group (24.5% of the referred cases) nonsurgical retreatment was judged by an endodontist as either impossible or improbable because it might jeopardize the root integrity. Retreatment should have been the preferred treatment modality for the rest of the group, provided that coronal restorations could be safely bypassed or removed. Posts were found in 63 of these teeth, however 35 of them were either short or loosely fitting and could safely be removed. The rest of the posts were longer than 5 mm, which might have presented a problem if their removal was attempted. In 45% of the 200 cases in the present study, surgical intervention was justified. The rest of the cases (55%) should have either been subjected to a follow-up (10.5%) or retreated nonsurgically by a skilled endodontist (44.5%). These results indicate that referring dentists may not appreciate the retreatment possibilities offered by modern endodontics, and they emphasize the need for a shift of concept: endodontists should be involved in the decision making before referring a patient to surgery.

Apicoectomy↗