ABSTRACT
The purpose of this in vitro study was to determine whether adhesive lining materials reduce microleakage in amalgam restorations, and to observe the degree of microleakage at the interface between freshly placed (new) and existing (old) amalgam. Forty-eight specimens were used in the experimental groups. The materials used to study microleakage in this investigation were: copal varnish, a dentin bonding agent (Clearfil New Bond), and a 4-META adhesive (Amalgambond). No significant difference in microleakage was found at the interfaces between freshly placed and existing amalgam. Significantly less microleakage was noted in specimens using the 4-META adhesive and the dentin bonding agent as compared to specimens in which no lining material was placed. Significantly less microleakage was noted in specimens using the 4-META adhesive compared to specimens using cavity varnish.
Subject(s)
Dental Amalgam , Dental Bonding , Dental Leakage/prevention & control , Dental Prosthesis Repair , Resin Cements , Analysis of Variance , Composite Resins , Dental Alloys , Dental Cavity Lining , Dentin-Bonding Agents , Humans , Methacrylates , MolarABSTRACT
The purpose of this study was to compare the shear and flexural strength obtained when various adhesives or liners were used to bond freshly placed amalgam to existing amalgam. The adhesives used in this study were the following: cavity varnish, 4-META adhesive (Amalgambond), and a dentin bonding agent (Clearfil New Bond). After samples were fabricated, shear bond strengths were determined by using an Instron Testing Machine, and flexural strengths determined using a Material Test System (MTS) testing machine. All test groups produced shear and flexural strengths less than one half of the control group. The dentin bonding agent and the 4-META adhesive produced significantly higher shear and flexural strengths than the test group in which no lining material was used.
Subject(s)
Dental Amalgam , Dental Bonding , Dental Prosthesis Repair , Resin Cements , Analysis of Variance , Composite Resins , Dental Materials , Dental Stress Analysis , Elasticity , Materials Testing , Methacrylates , Resins, Plant , Tensile StrengthABSTRACT
The purpose of this study was to observe the interfaces between (1) dentin and amalgam and (2) freshly placed amalgam and existing amalgam using various adhesive liners. Specimens were randomly assigned to four equal groups for liner placement: Group I--control, no liner used; Group II--copal varnish; Group III--4-META adhesive; Group IV--dentin bonding agent. After liner placement and amalgam replacement, specimens set for 24 hours and were then thermocycled in 0.5% basic Fuchsin dye, sectioned, and SEM analyses performed. Microgaps appeared in a disjointed fashion at the interface between freshly placed and existing amalgam. The 4-META adhesive appeared to establish a bond between amalgam and tooth structure and, thus, diminished the microgap between amalgam and dentin.
