Sealing composite resin restorations with a cavity sealant.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
1. The following dental cements are listed in order of decreasing mean bonding strenghts on varnish-free dentin: polycarboxylate, zinc phosphate, EBA, Fynal, and CBA. 2. The application of either Copalite or Varnal decreased the dentinal bonding strength of polycarboxylate and zinc phosphate cements. There was no change for CBA cement. 3. The application of Copalite and Varnal increased the dentinal bonding strength for Fynal to the level of zinc phosphate cement on varnish-free dentin. 4. The dentinal bonding strength of EBA cement increased with the application of Varnal but not with Copalite.
Adhesion or surface roughness and discoloration at the interface between pulpinsulating materials and composite resins were taken as indications for interaction between the resins and the insulating materials. Some interaction occurred between all insulating materials and resins investigated. After separation of the restorative resins, the interaction of Dycal with the different composite resins varied considerably and decreased in the following sequence: Opotow, Natural, and Adaptic. The interactions of ZOE with Natural and with Adaptic were similar and more pronounced than the interaction at the Adaptic-Dycal interface but less pronounced than at the Dycal-Natural interface. A very thin film of Tubulitec was found to adhere to the composite resins in some areas. The adherence of liners containing calcium hydroxide to dentin was found to be generally stronger than the bond between these liners and composite resins. Separation of the composite resins caused tears in the varnishes and frequently in Hydroxyline. Almost completely intact layers of the varnish Copalite were observed on dentin, but Zahnlack apparently dissolved to a great extent in the resins. Among the liners containing calcium hydroxide, Dycal and Tubulitec were found to give rise to a high pH in samples of saliva, but Hydroxyline did not. Porosity and a folded surface were observed for Hydroxyline, indicating the entrapment of the solvent beneath a dry superficial layer.
The pulpal irritation, such as inflammatory reaction and aspiration of pulpal cells, demonstrated after insertion of the zinc oxide/eugenol cement (Nobetec) seems to warrant the following recommendations: (1) A temporary restoration with a zinc oxide/eugenol base should not be inserted in deep cavities without a protective liner or a calcium hydroxide base covering the exposed dentinal tubules. (2) Before the temporary cementing of inlays and crowns with a zinc oxide/eugenol cement, not only should the dentin be properly cleaned and debris removed, but the prepared surfaces should be covered with a calcium hydroxide liner.
No significant increase or decrease in microleakage occurred as a result of single or double burnishing of amalgam. When cavity varnish use was compared with no use of cavity varnish, significantly less microleakage was noted with the nonburnished control, single-burnish, and double-burnish techniques utilizing the cavity varnish. It was concluded that burnishing is not a factor in microleakage when using Optaloy, but microleakage can be reduced by the use of a cavity liner such as Copalite.
Explore the source record for details and available documents.
The considerable decrease in microkeakage in the compound-reinforced restorations may be due to the tighter fit of the matrix band at the gingival wall of the preparation, which allows better condensation and marginal sealing of the restoration. The compound prevents lateral migration of the band during condensation pressures.
Explore the source record for details and available documents.
Temperature diffusion was monitored through in vivo restorations with and without bases 0.5 and 1 mm thick. Temperature diffusion was highest through amalgam restorations and slowest through unfilled resin restorations. The rate of diffusion through composite resins and silicate cement fell between the extremes. Bases of both zinc phosphate cement and zinc oxide-eugenol cement reduced the rate of temperature change on the floor of the cavity beneath amalgam restorations. The temperature change was generally less under the 1 mm base than the 0.5 mm base. Bases used beneath the nonmetallic restorations did not reduce the magnitude of temperature change on the cavity floor.
Conclusions reached within the constraints of this study showed the following: 1. Fracture strength of Class II amalgam restorations decreased as the thickness of the bases increased. 2. Fracture strengths of amalgam restorations based with different thicknesses of zinc phosphate cement underline with 0.5 mm Dycal were not different from each other. 3. The strength of the restorations varied with the type of base. Zinc phosphate cement is equal to no base and superior to zinc phosphate cement plus Dycal, which is equal to Dycal. Dycal is superior to Cavitec, which is the same as Cavitec plus Dycal. 4. The base materials did not fracture. The amalgam restorations were stronger over a base with a higher modulus of elasticity, indicating that modulus of elasticity of a base is more important than compressive strength in supporting an amalgam restoration. 5. There is no advantage (no improvement in resistance to fracture of the amalgam restoration) to be gained from placing zinc phosphate cement over Dycal. 6. When a calcium hydroxide liner is not needed, the cements with a higher modulus of elasticity, such as zinc phosphate cement and reinforced ZOE, will provide for stronger amalgam restorations than Cavitec and unreinforced ZOE.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Simulated clinical experiments showed that the hand condensation of amalgam on single or multiple layers of Dycal in Class II cavities does not cause significant fracture or displacement of the liner. Cyclic loading experiments demonstrated that the plastic deformation of Dycal decreases and its stiffness increases with each additional load cycle. This indicates that minor displacement of Dycal during amalgam condensation occurs mainly during the first thrusts with the condenser, and that its mechanical properties are improved by repeated condensation with heavy pressure. Cyclic loading tests may be of considerable value in the evaluation of the performance of liners during amalgam condensation.
Explore the source record for details and available documents.
To study the appearance of a cavity varnish and a cavity liner on prepared enamel and dentin surfaces, longitudinal tooth sections were coated once or twice with Copalite or Tubulitec. Some test specimens were immersed in saline solution for 24 hours, while others were kept in air. They were observed in SEM, and the degree of coverage of the test surfaces, and the smoothness of the materials were evaluated. Neither material provided complete coverage whether one or two layers were applied. Tubulitec seemed to be partially dissolved after immersion in saline solution. Generally, Copalite covered the surfaces better and was smoother than Tubulitec. These findings have implications in regard to the ability of the materials to protect the underlying tissues and to prevent microleakage, which were discussed.
Explore the source record for details and available documents.