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This study evaluated the clinical performance of a self-etching adhesive for resin composites over one year. Thirty pairs of restorations of Pertac II, using the adhesive Prompt L-Pop, were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. One of each pair was cured using "soft-start" polymerization, while the other was polymerized with high-intensity halogen light. Restorations were clinically evaluated at baseline, six and 12 months using modified Ryge/USPHS criteria. Although no significant difference (p>0.05) was observed between the curing methods, adhesive performance was poor, with a 35% loss of restorations overall.

The purpose of this study was to compare the effect of various finishing sequences on the surface roughness of four new light-activated (LAGIC) restorative materials. Restorative materials included a polyacid-modified composite resin (Variglass VLC) and three resin-modified glass-ionomer cements (Vitremer, Photac-fil, and Fuji II LC). Thirty specimens of each material were prepared in Macor dies and randomly divided into six finishing sequence groups (n = 5): (1) Mylar strip (control), (2) carbide bur/Sof-Lex XT disks, (3) ET finishing diamonds, (4) carbide bur/Enhance polishing system, (5) carbide bur/Politip rubber finishers, and (6) carbide bur alone. Average surface roughness (Ra) in micrometers was measured with a Mitutoyo Surftest 401 Surface Roughness Tester and the data compared using ANOVA, Student-Newman-Keuls Multiple Comparison tests, and Dunnett's test at P < or = 0.05. Surface topography was also assessed using the scanning electron microscope (SEM) on epoxy replicas from samples of each group. The Mylar strip produced the smoothest surface and finishing sequences; (2) and (3) were significantly smoother than (4), (5), and (6). There were no significant differences between restorative materials when all finishing sequences were combined. SEM analysis was consistent with the profilometer results. Materials with higher (Ra) values appeared to have rougher surfaces. Rubber abrasives and polishing pastes seem to preferentially remove the polysalt and resin matrix of these materials.

The purpose of this investigation was to determine the effect of dentin primers from Scotchbond Multi-Purpose, ProBond, All-Bond 2, and Syntac on the shear bond strength of composite resin to etched enamel. Two groups of extracted human molar teeth with flattened enamel surfaces (n = 12) were randomly assigned to each enamel/dentin bonding system. Following manufacturers' instructions enamel surfaces were etched, rinsed, and dried. Composite bonding procedures were conducted similarly in both groups for each enamel/dentin bonding system, except that in one of the two groups, dentin primer was applied prior to adhesive resin and composite placement. Samples were thermocycled and tested in shear until failure. Fracture analysis was performed on enamel surfaces with both light and scanning electron microscopy. Shear bond values (Mean +/- SD, MPa) were: Scotchbond Multi-Purpose unprimed 22.4 +/- 3.2, primed 17.9 +/- 5.9; ProBond unprimed 19.4 +/- 6.2, primed 18.3 +/- 3.3; All-Bond 2 unprimed 19.0 +/- 3.6, primed 17.3 +/- 3.0; and Syntac unprimed 26.2 +/- 9.0, primed 22.0 +/- 5.4. The only significant difference found between primed and unprimed groups was with Scotchbond Multi-Purpose, though there was a trend for primer application to decrease enamel bond strengths. Fracture surface analysis revealed that most failures were cohesive within the composite resin. These data suggest that the effect of primer on bonded composite resin to etched enamel is material specific.

The esthetic restoration of anterior root canal-treated teeth with significant loss of tooth structure is a challenging clinical situation. For younger patients or for patients requiring interim treatment plans, restoring badly broken-down anterior teeth with composite resin provides an expedient and esthetic solution. Current visible-light-activated composite resin materials require an incremental build-up to ensure adequate depth of cure. With the use of custom-contoured, stabilized, thin crown forms and strategically placed vent holes, the clinician can efficiently provide cost-effective direct composite resin restorations that meet the patients' esthetic needs.

Amalgambond (a 4-META derivative resin bond agent) was evaluated for its effectiveness in reducing microleakage compared to copal varnish and no lining agent in class 5 amalgam preparations restored with either an admix alloy (Dispersalloy) or a spherical alloy (Tytin). Teeth were thermocycled between 5 and 55 degrees C with two 4-META/amalgam groups additionally aged in 37 degrees C water for 30 days prior to thermocycling. Nonaged, 4-META/amalgam restorations showed significantly less microleakage (P < 0.05) at enamel and dentin margins compared to copal varnish or nonlined restorations. Within the 4-META groups, the 4-META/Dispersalloy restorations had significantly less microleakage than the 4-META/Tytin restorations at enamel margins. Microleakage in the aged 4-META/amalgam restorations was significantly greater at both the enamel and dentin margins than in the analogous nonaged groups. SEM evaluation of the 4-META lined restorations found internal cavity surfaces of the preparations to be sealed by the resin liner with separations and apparent microleakage occurring at the 4-META/amalgam interface.