Microleakage of Permanent Restorations in Endodontically Treated Teeth

Objectives: The purpose of this in vitro study was to investigate by dye penetration the microleakage of permanent restorative materials used to seal access cavities in endodontically treated teeth. Methods: Occlusal endodontic access cavities were prepared in 30 intact premolar teeth and restored with equal numbers of 3 commonly used plastic materials viz. - a high copper amalgam after sealing the cavity with copal varnish, composite resin after sealing with Prime & Bond NT, and a resin-modified glass ionomer (GC Fuji II LC) in a conditioned cavity. Three additional intact premolars were used as negative controls, and a further 3 with unrestored access cavities acted as positive controls. All specimens were subjected to 1000 thermal cycles alternating between 5ºC and 55ºC in water, then immersed in dye for 24 hours. Specimens were longitudinally sectioned then photographed with a calibrated digital camera. Image analysis software was used to identify and measure the relative amounts of micro-leakage alongside each material. Statistical analysis of the depths of dye penetration in the control and experimental groups using ANOVA and T-tests was undertaken. Results: The amounts of microleakage in all three experimental groups were significantly different from one another (p= 0.000<0.001). Amalgam restorations lined with copal varnish showed less micro-leakage than the other materials (p<0.0001). Composite showed less microleakage than glass ionomer. Conclusions: Access cavities of endodontically treated teeth should be sealed with amalgam restorations lined with copal varnish, and not with composite or glass ionomer, if microleakage is to be minimised.