The purpose of this investigation was to compare the bond strengths to enamel obtained in shear/peel and tensile/peel modes of testing using five different ceramic brackets and two different light-cured composites. The site of failure was also examined. Shear/peel bond strength was significantly affected by adhesive type, with Heliosit having higher mean bond strengths than Prismafil. Bond strength was significantly affected by bracket type; the highest mean bond strength in both tests being attained using Transcend with Heliosit. All brackets resisted shear/peel forces better than tensile/peel forces. High bond strengths are associated with an increased incidence of bracket and enamel fractures with Transcend and Starfire.

This is a relatively new technique and to date there remains a lack of evidence of long-term stability of anterior open bite closure with TAD.

The shear/peel and tensile/peel bond strengths of mesh-backed orthodontic brackets bonded to porcelain, using a highly filled composite and four different silane bonding agents were determined. Sites of failure were recorded for each method of testing. A method of debonding and restoring the procelain surface to its original state after debonding was also investigated. All silane bonding systems tested provided adequate bond strength for clinical use. Fusion produced significantly higher force values to failure in shear testing. There was no significant difference between the bond strengths obtained in tensile testing. Patterns of failure differed in each mode of testing, suggesting that a shear mode of debonding is more likely to cause porcelain fracture and that the possibility of porcelain fracture during function or debonding cannot be excluded. The use of a Lift-Off plier is recommended in debonding brackets from porcelain where a silane bonding agent has been used. Diamond polishing paste was better at restoring the procelain surface to its original appearance than Shofu polishing stones.

No abstract

A pre-production sample of zirconium oxide (ceramic) brackets was examined in this study. A laboratory investigation of the tensile/peel bond strength of the brackets was carried out using two light-cured adhesives (Prismafil and Heliosit) and one chemically-cured adhesive (Delphic). The mode of failure was also investigated using optical and scanning electron microscopy. The bond strengths achieved with Prismafil were statistically significantly (P < 0·05) lower than Heliosit and Delphic between which no significant differences were found. All samples failed at the bracket—adhesive interface. A clinical test demonstrated the extreme ease of sliding along stainless steel and nickel-titanium archwires. and revealed a low plaque adhesion. The principal disadvantage of these brackets appears to be their off-white highly opaque appearance which in addition to giving poor aesthetics may adversely affect bond strength with light-cured adhesives.