Apical leakage in canals filled with glass ionomer sealer and gutta-percha after dentin conditioning

The use of glass ionomer cements in both conventional and surgical endodontics

The capacity to bond to dental tissues, especially to dentine, their long-term fluoride release and their biocompatibility make glass ionomer cements (GICs) advantageous for use in endodontics, as well as in restorative dentistry. This review provides information on the basic properties of GICs, such as adhesion, antimicrobial effects and biocompatibility, particularly as they relate to use in endodontics. Indications for the use of GICs in endodontics are orthograde root canal sealing, root-end filling, repair of perforations and root resorption defects, treatment of vertical fractures and maintenance of the coronal seal. The paper includes a review on each of these indications. It is concluded that in spite of the critical handling characteristics and the inconclusive findings regarding sealing ability and antimicrobial activity, there is substantial evidence to confirm their satisfactory clinical performance. Both soft tissue and bone compatibility make them suitable for use during endodontic surgery.

The shear bond strength of glass ionomer cement sealers to bovine dentine conditioned with common endodontic irrigants

AIM

The aim of this in vitro study was to evaluate the shear bond strength of commercially available and experimental glass ionomer cement (GIC) sealers to dentine exposed to common endodontic irrigants.

METHODOLOGY

The enamel of 90 bovine incisor crowns, randomly divided into nine equal groups, was ground to expose the superficial dentine layer. The exposed surface was conditioned with either: (i) distilled H2O; (ii) 2.6% NaOCl; or (iii) 17% EDTA followed by 2.6% NaOCl. Five cc of each irrigant was applied over a 30-second period. The following GIC sealers were tested: (i) Ketac-Endo; (ii) KT-308, an experimental sealer; and (iii) ZUT, a combination of KT-308 and an antibacterial agent (0.2% by weight). The test sealers were applied to form cylinders with a standardized contact surface area (17.8 mm2) on the conditioned dentine surfaces. Specimens were bench set for 90 min and stored in distilled water at 37 degrees C for 48 h, then tested to failure for shear bond strength (MPa) in an Instron machine.

RESULTS

KT-308 and ZUT had significantly higher MPa values than Ketac-Endo (two-factor ANOVA, P < 0.0001), regardless of the dentine conditioning. All specimens conditioned with 17% EDTA and 2.6% NaOCl combined had significantly lower MPa values than those conditioned with water or 2.6% NaOCl alone (P < 0.02).

CONCLUSIONS

It was concluded that the experimental sealers KT-308 and ZUT bonded better to bovine dentine than Ketac-Endo, and that the bond of all three GIC sealers was better with the smear layer present.

Dental materials: 1997 literature review

This review of the published literature on dental materials for the year 1997 has been compiled by the Dental Materials Panel of UK. It continues a series of annual reviews started in 1973. Emphasis has been placed upon publications, which report upon the materials science or clinical performance of the materials. The review has been divided by accepted materials classifications (fissure sealants, glass polyalkenoate cements, dentine bonding, dental amalgam, endodontic materials, casting alloys, ceramometallic restorations and resin-bonded bridges, ceramics, denture base resins and soft lining materials, impression materials, dental implant materials, orthodontic materials, biomechanics and image processing, resin composites, and casting investment materials and waxes). Three hundred and thirty three articles have been reviewed.