Interfacial fracture toughness between resin-modified glass ionomer and dentin using three different surface treatments.
OBJECTIVE
To identify the long-term dentin-resin modified glass ionomer cement (RMGIC) interfacial fracture toughness (FT) using three different dentin surface treatments prior to RMGIC placement. Fuji II LC (GC America) was bonded to dentin using cavity conditioner (CC), Scotchbond Multipurpose (3M ESPE) complete system (SS), or Scotchbond etching and priming without adhesive (SP). Twenty-four teeth were used for each of the three groups.


METHODS
Two samples were obtained from each tooth and they were stored in artificial saliva (AS) or oil for 1- or 24-weeks before determining interfacial FT. The results were fit to Weibull distributions with log-rank and Wilcoxon tests for comparison of failure curves over time for each experimental condition. Statistical analysis was performed at a 0.05 level of significance.


RESULTS
FT values in artificial saliva were as follows: 1 week SS=SP>CC, 6 months SS>SP=CC; in oil SS=SP=CC for both storage times. A significant decline in FT occurred between 1- and 24-week storage for SS and SP. Storage in oil, on the other hand tended to increase FT values for all groups.


CONCLUSIONS
These observations support findings of hydrolytic degradation in adhesive resin-based surface treatments.
Setien
Victor J
VJ
Restorative Dentistry Department, Facultad de Odontologia, University of the Andes, Calle 24 entre Av 2 y 3, Merida 5101, Venezuela. vsetien@ula.ve
Armstrong
Steven R
SR
Wefel
James S
JS
D000134:Acid Etching, Dental / Q000379:methods; D000180:Acrylic Resins; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D006801:Humans; D008422:Materials Testing; D009821:Oils; D063065:Organophosphonates; D011897:Random Allocation; D019279:Resin Cements; D012117:Resins, Synthetic; D012464:Saliva, Artificial; D013499:Surface Properties; D016019:Survival Analysis
D000180:Acrylic Resins; D017220:Dentin-Bonding Agents; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D009821:Oils; D063065:Organophosphonates; D019279:Resin Cements; D012117:Resins, Synthetic; D012464:Saliva, Artificial; C084018:Scotchbond Multi-Purpose; C454540:Scotchbond etchant; C006903:carbopol 940