Coronal Microleakage Research Articles

A study of suitability of referrals for periradicular surgery.

To determine if the clinical and radiographic presentation of patients referred by their general dental practitioner requesting periradicular surgery fulfilled a set of predetermined guidelines as to the appropriateness of the procedure. Multicentre prospective study. Maxillofacial departments of district general hospitals. Consecutive analysis of referrals within four hospitals over a 1-year period between 1995 and 1996. From 205 referrals, mostly of patients in the 30 to 40 years age group, 79.5% (n = 163) of referrals failed to meet the criteria, mainly because of an unsatisfactory root canal filling, but also due to obvious coronal microleakage and adjacent teeth contributing to the disease process not yet having received endodontic treatment. In only 6.3% (n = 13) of patients had there been an attempt to retreat the pulp space infection by conventional means. The majority of referrals in this study did not fulfil the guideline criteria on the provision of periradicular surgery. The factors influencing failure in endodontics and periradicular disease did not appear to have been appreciated, or were not acted upon. Conventional retreatment of the pulp space needs to be considered or attempted prior to referral for surgery.

An in vitro study of coronal microleakage in root‐canal‐treated teeth restored by the post and core technique

The aims of this study were to compare coronal microleakage around cast and prefabricated post and cores and to examine the coronal seal achieved by temporary post crowns. Thirty extracted, single-rooted, human teeth were prepared chemomechanically, root filled with gutta-percha and sealer and prepared for a standard post. Three groups, each of 10 teeth, were restored with either: (i) cast post and cores cemented with zinc phosphate cement; (ii) prefabricated posts and composite cores cemented with a composite luting cement; or (iii) temporary post crowns cemented with a temporary zinc oxide-eugenol cement. The teeth were thermocycled and placed in Indian ink for 1 week, then demineralized and rendered transparent. Linear coronal dye penetration around the posts was measured and recorded. Results indicated that while cast post and cores and prefabricated posts and composite cores produced a good seal, leakage was significantly greater with temporary post crowns (P < 0.05). It is concluded that to prevent re-infection of the root canal system, it may be preferable to restore the tooth immediately with a prefabricated post and composite system rather than place a temporary post crown and subsequently a cast post and core.

An in vitro study of coronal microleakage in root-canal-treated teeth restored by the post and core technique

An in vitro study of coronal microleakage in root-canal-treated teeth restored by the post and core technique

Coronal leakage: Effects of smear layer, obturation technique, and sealer

Coronal microleakage may be a major factor in the etiology of treatment failure. This study examined the effect of obturation technique, sealer, and the presence of smear layer on coronal microleakage. Two hundred extracted human teeth were assigned to 20 treatment groups. Groups were examined with the smear layer present or smear layer removed (17% REDTA). Access cavities were exposed to artificial saliva then Pelikan Ink. Teeth were cleared and linear dye penetration measured. When all groups with the smear layer removed were compared with all groups with the smear layer present, significantly less leakage was seen when the smear layer was removed. Ultrafil displayed significantly more leakage than all other groups. Vertical compaction of lateral condensation and Thermafil obturations significantly reduced leakage. AH-26 displayed significantly less leakage than Roth's 811 sealer. These results indicate that removal of the smear layer, the use of AH-26, and vertical compactin have cumulative effects in reducing coronal leakage.

OR 34 Intraorifice sealing of obturated root canals to prevent coronal microleakage

OR 34 Intraorifice sealing of obturated root canals to prevent coronal microleakage

An in vitro evaluation of coronal microleakage in obturated root canals without coronal restorations

A study was conducted to evaluate coronal microleakage of Super EBA and Ketac-Endo when used as sealers with single-cone gutta-percha (GP) root canal obturation. The root canals of 24 extracted human teeth were instrumented with flared preparations to a minimum #40 master apical file size. Ten teeth were obturated with a single GP cone and Super EBA as the sealer and ten teeth were obturated with a single GP cone and Ketac-Endo as the sealer. Four teeth were used as controls. Salivary bacterial microleakage studies were conducted to determine whether these sealers could prevent coronal microleakage through the root canal in the absence of a coronal tooth restoration. There was no bacterial penetration through the apical foramen for either sealer tested during the 60-day test period.

Effect of smear layer on coronal microleakage

The purpose of this study was to examine the effect of smear layer on coronal microleakage. Fifty-two single-rooted extracted human teeth with a straight root canal were chemomechanically prepared and equally divided into experimental groups A and B. The teeth in group B were treated with ethylenediamine tetraacetic acid and sodium hypochlorite to remove the smear layer. All teeth in the experimental groups were next obturated with gutta-percha and sealer. Finally they were tested for dye leakage with methylene blue. Linear and volumetric measurement of dye penetration was used to assess leakage. The results of this study suggest that the removal of smear layer significantly improves the tightness of the sealing in the coronal area.

Evaluation of coronal microleakage after endodontic treatment

A new method is suggested for placing a coronal seal in the orifice of the root canal right after root canal therapy. Root canal therapy was done on 94 extracted human maxillary centrals. Three mm of the coronal gutta-percha was replaced by either Cavit, TERM, or amalgam with cavity varnish. After thermocycling and 2 wk of immersion in dye, the amount of dye penetration was measured. The results showed that amalgam with two coats of cavity varnish sealed significantly better than Cavit and TERM. However, Cavit and TERM were still significantly better than a positive control group.

PC 27 Apical and coronal microleakage of two root canal filling techniques

Root Canal Filling Techniques. M. Carter, S. Frost, V. Karapanou*, C. Pastan, M. Goldman, R. White, Tufts University, Boston, MA This study assessed apical and coronal dye leakage of a single gutta percha cone, resin sealer, filling technique compared with lateral condensation of gutta percha and sealer. 68 single canal teeth were instrumented to an apical size of 40 using a crown-down, step-back technique. To remove the smear layer, final irrigation with 15% E.D.T.A. was followed by 5.25% NaOCl. The teeth were then randomly divided into 2 groups of 30 and 4 controls. 30 samples in Gr. A were filled using lat. condensed g.p. and Z.O.E. sealer. A single fitted cone and resin sealer were used to fill the 30 teethin Gr. B. (+) controls were filled with loosely fitted g.p. w/out sealer. (-) controls were covered with sticky wax. Wax covered all but the apical foramen in 15 teeth from Gr. A and B. Wax covered all surfaces except the coronal access of the remaining 15 teeth in each group. After 7 days, all samples were placed in 2% methylene blue under a vacuum. The samples were then split longitudinally and measured for leakage by 2 examiners. Inter-examiner reliability correlated_. A students' T test demonstrated that the resin sealer demonstrated siqnificantly less coronal leakaqe than lateral condensation. There was no siqnificant difference in the apical leakaqe.

Influence of a base on coronal microleakage of post-prepared teeth

This study compared the coronal microleakage of post-prepared teeth with and without the placement of a zinc oxide-eugenol cement seal coronal to the gutta-percha. Forty single-rooted extracted teeth were prepared and obturated with sealer and gutta-percha. These teeth were divided into two groups of teeth 20 each. A post space was prepared for each tooth so that 5 to 6 mm of gutta-percha remained in one group and 3 to 4 mm in the other group. To the latter group, 2 to 3 mm of zinc oxide-eugenol cement base was placed directly coronal to the gutta-percha. The sealer was allowed to set for 48 h and the outer root surfaces of the teeth were covered with finger nail varnish and sticky wax, except for the access openings. The teeth were immersed in dye for 1 wk to allow coronal microleakage. The specimens were sectioned and measurements were made on the extent of dye penetration into the root filling. The teeth without a zinc oxide-eugenol base showed significantly greater microleakage than those protected with a zinc oxide-eugenol base.

An evaluation of three materials as barriers to coronal microleakage in endodontically treated teeth

Barrier Dentin Sealant, glass ionomer cement, and TERM were evaluated as possible barriers to coronal microleakage. The root canals of 70 extracted teeth were accessed, cleaned and shaped, and then obturated with gutta-percha and sealer. The teeth were divided into four groups, one for each barrier material evaluated and one control group. Subgroups were stored in a humidor or immersed in artificial saliva for 7 days and then placed in methylene blue dye. Barrier Dentin Sealant and TERM groups demonstrated the lowest dye penetration measurements. The difference between them was not statistically different. Glass ionomer cement demonstrated the greatest dye penetration and was statistically different from the other two barrier materials.

Abstract #9 — An evaluation of three materials as barriers to coronal microleakage in endodontically treated teeth

Abstract #9 — An evaluation of three materials as barriers to coronal microleakage in endodontically treated teeth

Abstract #29 — Effect of bleaching on coronal microleakage of endodontically treated teeth

Abstract #29 — Effect of bleaching on coronal microleakage of endodontically treated teeth

MEDICATIONS AND TEMPORARIES IN ENDODONTIC TREATMENT

We have attempted to present in this article an overview of the medications used as intracanal dressings during root canal treatment and the materials used to seal endodontic access preparations. Because all the medications reviewed have an antimicrobial effect (with the exception of steroids), they seemingly would be useful in root canal treatment. However, the potentially harmful side effects of the chemical agents, which include cytotoxicity and antigenicity, may make the treatment worse than the cure. With an improved understanding of the principles of root canal cleaning, strong medications placed into canals may be unnecessary. At best, intracanal dressings should be used only in situations that might benefit from such therapy. Temporary restoration of endodontically treated teeth is an essential part of root canal therapy. Commonly used materials and techniques for their uses have been presented. With proper temporization and timely final restoration, the potential for coronal microleakage will be minimized.

Human saliva coronal microleakage in obturated root canals: An in vitro study

This study assessed salivary penetration through obturated root canals as related to time by using two methods of analysis--histological examination and dye penetrations. A total of 160 human maxillary anterior teeth were instrumented to size 60 Hedstrom file. Ten of the teeth were not obturated; 150 teeth were obturated by lateral condensation of gutta-percha and Roth's root canal sealer. Fifty of these teeth received intermediate restorative material temporaries to a thickness of approximately 3 mm. All teeth were immersed in 50 ml of whole human saliva and kept at 37 degrees C and 100% humidity. The saliva was changed daily. At 2, 7, 14, 28, and 90 days, 32 teeth were removed from the saliva. Of these, two were unobturated and were examined for bacterial penetration by culturing of the apical one-third. Ten teeth without temporaries were immersed in Pelikan ink for 2 days to demonstrate the extent of salivary penetration. These teeth were decalcified and cleared to allow direct measurement of dye penetration. Decalcified serial 7-microns-thick sections were prepared from the remaining 20 teeth, 10 with and 10 without intermediate restorative material temporaries. The sections were stained with hematoxylin and eosin stain and Brown and Hopps stain. Saliva penetration assessed in histological sections was significantly less than was visualized with dye analysis. Salivary penetration at 3 months was significantly greater than at the four earlier study periods. This amount of salivary penetration was considered to be clinically significant. The results strongly suggest retreatment of obturated root canals that have been exposed to the oral cavity for at least 3 months.

Restoration of endodontically treated anterior teeth: An evaluation of coronal microleakage of glass ionomer and composite resin materials

A glass ionomer material was evaluated for coronal microleakage in permanent lingual access restorations of endodontically treated anterior teeth. The material was tested as a restoration, placed over a zinc oxide-eugenol base, and as a base with an acid-etched composite resin veneer and a dentinal bonding agent. Restored teeth were thermocycled, immersed in silver nitrate, developed, and sectioned to assess microleakage. Significant coronal leakage was observed with all materials used.

A comparative in vitro coronal microleakage study of new endodontic restorative materials

Complete sealing of endodontic access openings between appointments and after completion of therapy is an essential element in achieving endodontic success. Recently, two new products for use as temporary restorative materials, TERM and Dentemp, have become available. The purpose of this study was to compare in vitro the sealing ability of Cavit, Cavit-G, Cavit-W, and IRM-Caps, with TERM, Hard-TERM, and Dentemp. Standard access cavities were prepared in 144 intact extracted human teeth. They were equally and randomly distributed into seven groups, and their access openings were temporized. Specimens were submitted to thermocycling (5 to 55 degrees C) for 7 days and stained with silver nitrate. The teeth were split in half, and the greatest depth of dye penetration at the tooth surface was recorded. TERM exhibited the least leakage, while Hard-TERM demonstrated the greatest leakage, at the tooth-restoration interface.

A comparison of two temporary restorations: Light-cured resin versus a self-polymerizing temporary restoration

Temporary restorative materials are an important component of endodontic therapy. They must both adequately seal the access preparation between visits and protect the obturated canal(s) from microleakage until a permanent restoration can be placed. The efficacy of Cavit and T.E.R.M. (a new light-cured composite product) was compared with the use of a carbon black coronal microleakage protocol. The teeth examined had previously received coronal restorations. After the teeth were accessed, restored with Cavit or T.E.R.M., and exposed to the dye, they were cleared. Three-dimensional assessment then revealed that Cavit more consistently provided an effective seal. In addition, a great deal of microleakage was observed around the permanent restoration-tooth interface. This indicates that perhaps leaking permanent restorations should be removed in their entirety before initiation of endodontic treatment.

Coronal microleakage of permanent lingual access restorations in endodontically treated anterior teeth

Forty-six intact extracted human anterior teeth were treated endodontically with laterally condensed gutta-percha and sealer. The teeth were restored with a base of either zinc phosphate or temporary stopping and a permanent restoration of either acid etched composite resin with GLUMA as the dentin bonding agent or with Ketac-Fil glass ionomer. The teeth were thermocycled, coated with nail varnish (except for the access), immersed in silver nitrate, developed, and sectioned longitudinally. The linear dye penetration was measured. All restorations permitted leakage into the base. All groups had specimens which leaked into the gutta-percha. There was a tendency for the glass ionomer/zinc phosphate group to leak least, but there were no statistically significant differences among the groups.

An evaluation of coronal microleakage in endodontically treated teeth. Part III. In vivo study

Root canal therapy was performed on posterior teeth in monkeys using gutta-percha and various sealers for obturation. The access openings were restored with zinc oxide-eugenol. Seventy-two hours later, the temporary restorations were removed and the coronal openings exposed to the oral environment for 1 wk. Following removal, the teeth were placed in dye and cleared to allow visualization of dye penetration. The results showed the presence of dye in teeth in all groups with no significant differences among the groups. Root canal therapy was performed on posterior teeth in monkeys using gutta-percha and various sealers for obturation. The access openings were restored with zinc oxide-eugenol. Seventy-two hours later, the temporary restorations were removed and the coronal openings exposed to the oral environment for 1 wk. Following removal, the teeth were placed in dye and cleared to allow visualization of dye penetration. The results showed the presence of dye in teeth in all groups with no significant differences among the groups.